1.
San Augustine County, Texas
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San Augustine County is a county located in the U. S. state of Texas. As of the 2010 census, its population was 8,865 and its county seat is San Augustine. San Augustine County was formed in 1837 and it was supposedly named after the Saint, Augustine of Hippo. However, it seems plausible that the county was named for the town of San Augustine, according to the U. S. Census Bureau, the county has a total area of 592 square miles, of which 531 square miles is land and 62 square miles is water. The population density was 17 people per square mile, there were 5,356 housing units at an average density of 10 per square mile. The racial makeup of the county was 69. 26% White,27. 95% Black or African American,0. 20% Native American,0. 20% Asian,1. 64% from other races,3. 58% of the population were Hispanic or Latino of any race. 27. 00% of all households were made up of individuals and 14. 90% had someone living alone who was 65 years of age or older, the average household size was 2.43 and the average family size was 2.93. In the county, the population was out with 23. 70% under the age of 18,6. 80% from 18 to 24,23. 00% from 25 to 44,25. 10% from 45 to 64. The median age was 42 years, for every 100 females there were 92.10 males. For every 100 females age 18 and over, there were 85.90 males, the median income for a household in the county was $27,025, and the median income for a family was $32,772. Males had an income of $28,395 versus $18,925 for females. The per capita income for the county was $15,548, about 15. 60% of families and 21. 20% of the population were below the poverty line, including 30. 70% of those under age 18 and 20. 10% of those age 65 or over. At the presidential level, San Augustine County has voted for the Republican candidate in every election since 2000, like many areas of the South, while Republicans generally win federal and state elections, Democrats tend to perform better in down-ballot races for local offices. Identification with the Democratic Party is strong in San Augustine County, at the Federal level, San Augustine County is part of the 1st Congressional District, which is currently represented by Louie Gohmert, a Republican from Tyler. In the Texas Legislature, the county is represented by State Representative Trent Ashby, and by State Senator Robert Nichols
San Augustine County, Texas
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The San Augustine County Courthouse
San Augustine County, Texas
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Rural school children, San Augustine County, Texas. Photograph by
John Vachon.
2.
U.S. Office of War Information
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OWI operated from June 1942 until September 1945. Through radio broadcasts, newspapers, posters, photographs, films and other forms of media, the office also established several overseas branches, which launched a large-scale information and propaganda campaign abroad. The Foreign Information Service, a division of the Office of the Coordinator of Information, at the onset of World War II, the American public was in the dark regarding wartime information. Further, the American public confessed a lack of understanding as to why the world was at war, President Roosevelt established the OWI to both meet the demands for news and less confusion, as well as resolve American apathy towards the war. The OWI’s creation was not without controversy, the American public, and the United States Congress in particular, were wary of propaganda for several reasons. First, the press feared a centralized agency as the distributor of wartime information. Second, Congress feared an American propaganda machine that could resemble Joseph Goebbels’ operation in Nazi Germany, third, previous attempts at propaganda under the Committee on Public Information/Creel Committee during WWI were viewed as a failure. And fourth, America was experiencing endemic isolationism and was hesitant to become involved in a propaganda campaign. The OWI’s operations were divided between the Domestic and Overseas Branches. In 1942 OWI established the Voice of America, which remains in service as of 2015 as the government broadcasting service of the United States. The VOA initially borrowed transmitters from the commercial networks, the programs OWI produced included those provided by the Labor Short Wave Bureau, whose material came from the American Federation of Labor and the Congress of Industrial Organizations. In conjunction with the War Relocation Authority, the OWI produced a series of films related to the internment of Japanese Americans. The OWI also worked with camp newspapers to disseminate information to internees, in addition, the OWI produced a series of 267 newsreels in 16 mm film, The United Newsreel which were shown overseas and to US audiences. These newsreels incorporated U. S. military footage, for examples see this Google list. The OWI Bureau of Motion Pictures worked with Hollywood to produce films that advanced American war aims, successful films depicted the Allied armed forces as valiant Freedom fighters, and advocated for civilian participation, such as conserving fuel or donating food to troops. By July 1942 OWI administrators realized that the best way to reach American audiences was to present war films in conjunction with feature films, OWIs presence in Hollywood deepened throughout World War II, and by 1943 every Hollywood studio allowed OWI to examine all movie scripts. OWI evaluated whether each film would promote the honor of the Allies mission, the Overseas Branch enjoyed greater success and less controversy than the Domestic Branch. Abroad, the OWI operated a Psychological Warfare Branch, which used propaganda to enemy forces in combat zones
U.S. Office of War Information
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Riveting team working on the cockpit shell of a
C-47 cargo plane at the plant of
North American Aviation
U.S. Office of War Information
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Pearl Harbor, Hawaii. A small boat rescues a seaman from the 31,800 ton USS West Virginia burning in the foreground.
U.S. Office of War Information
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Elmer Davis, Director of the Office of War Information, examines Nazi and Japanese propaganda organs.
U.S. Office of War Information
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M-4 tank crew. OWI photo, 1942.
3.
Immune system
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The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. To function properly, a system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms. In many species, the system can be classified into subsystems, such as the innate immune system versus the adaptive immune system. In humans, the barrier, blood–cerebrospinal fluid barrier, and similar fluid–brain barriers separate the peripheral immune system from the neuroimmune system. Even simple unicellular organisms such as bacteria possess a rudimentary immune system in the form of enzymes that protect against bacteriophage infections, other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants and invertebrates. These mechanisms include phagocytosis, antimicrobial peptides called defensins, and the complement system, jawed vertebrates, including humans, have even more sophisticated defense mechanisms, including the ability to adapt over time to recognize specific pathogens more efficiently. Adaptive immunity creates immunological memory after a response to a specific pathogen. This process of acquired immunity is the basis of vaccination, disorders of the immune system can result in autoimmune diseases, inflammatory diseases and cancer. Immunodeficiency occurs when the system is less active than normal. In humans, immunodeficiency can either be the result of a disease such as severe combined immunodeficiency, acquired conditions such as HIV/AIDS. In contrast, autoimmunity results from an immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimotos thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, immunology covers the study of all aspects of the immune system. Immunology is a science that examines the structure and function of the immune system and it originates from medicine and early studies on the causes of immunity to disease. The earliest known reference to immunity was during the plague of Athens in 430 BC, thucydides noted that people who had recovered from a previous bout of the disease could nurse the sick without contracting the illness a second time. In the 18th century, Pierre-Louis Moreau de Maupertuis made experiments with scorpion venom and observed that certain dogs and this and other observations of acquired immunity were later exploited by Louis Pasteur in his development of vaccination and his proposed germ theory of disease. Pasteurs theory was in opposition to contemporary theories of disease. It was not until Robert Kochs 1891 proofs, for which he was awarded a Nobel Prize in 1905, viruses were confirmed as human pathogens in 1901, with the discovery of the yellow fever virus by Walter Reed. Immunology made an advance towards the end of the 19th century, through rapid developments, in the study of humoral immunity
Immune system
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A
scanning electron microscope image of a single
neutrophil (yellow), engulfing
anthrax bacteria (orange)
Immune system
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A
scanning electron microscope image of normal circulating human
blood. One can see
red blood cells, several knobby white blood cells including
lymphocytes, a
monocyte, a
neutrophil, and many small disc-shaped
platelets.
Immune system
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An antibody is made up of two heavy chains and two light chains. The unique variable region allows an antibody to recognize its matching antigen.
Immune system
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The time-course of an immune response begins with the initial pathogen encounter, (or initial vaccination) and leads to the formation and maintenance of active immunological memory.
4.
Antigen
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In immunology, an antigen is a molecule capable of inducing an immune response on the part of the host organism, though sometimes antigens can be part of the host itself. In other words, an antigen is any substance that causes a system to produce antibodies against it. In most cases, an antibody can bind one specific antigen, in some instances, however. An antigen is a molecule that binds to Ag-specific receptors, Antigens are usually peptides, polysaccharides or lipids. In general, molecules other than peptides qualify as antigens but not as immunogens since they cannot elicit a response on their own. Furthermore, for a peptide to induce a response it must be a large enough size. The term antigen originally described a structural molecule that specifically to an antibody. It expanded to refer to any molecule or a molecular fragment that can be recognized by highly variable antigen receptors of the adaptive immune system. The antigen may originate from within the body or from the external environment, antigen presenting cells present antigens in the form of peptides on histocompatibility molecules. The T cells of the immune system recognize the antigens. Depending on the antigen and the type of the histocompatibility molecule, for T-Cell Receptor recognition, the peptide must be processed into small fragments inside the cell and presented by a major histocompatibility complex. The antigen cannot elicit the immune response without the help of an immunologic adjuvant, similarly, the adjuvant component of vaccines plays an essential role in the activation of the innate immune system. An immunogen is a substance that is able to trigger a humoral and/or cell-mediated immune response and it first initiates an innate immune response, which then causes the activation of the adaptive immune response. An antigen binds the highly variable immunoreceptor products once these have been generated, all immunogen molecules are also antigens, although the reverse is not true. At the molecular level, an antigen can be characterized by its ability to bind to an antibodys variable Fab region, different antibodies have the potential to discriminate among specific epitopes present on the antigen surface. A hapten is a molecule that changes the structure of an antigenic epitope. In order to induce a response, it needs to be attached to a large carrier molecule such as a protein. Antigens are usually proteins and polysaccharides, and less frequently, lipids and this includes parts of bacteria, viruses, and other microorganisms
Antigen
–
Contents
5.
Molecule
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A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge, however, in quantum physics, organic chemistry, and biochemistry, the term molecule is often used less strictly, also being applied to polyatomic ions. In the kinetic theory of gases, the molecule is often used for any gaseous particle regardless of its composition. According to this definition, noble gas atoms are considered molecules as they are in fact monoatomic molecules. A molecule may be homonuclear, that is, it consists of atoms of one element, as with oxygen, or it may be heteronuclear. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are not considered single molecules. Molecules as components of matter are common in organic substances and they also make up most of the oceans and atmosphere. Also, no typical molecule can be defined for ionic crystals and covalent crystals, the theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding, which means that solid metals are also not made of molecules. In glasses, atoms may also be together by chemical bonds with no presence of any definable molecule. The science of molecules is called molecular chemistry or molecular physics, in practice, however, this distinction is vague. In molecular sciences, a molecule consists of a system composed of two or more atoms. Polyatomic ions may sometimes be thought of as electrically charged molecules. The term unstable molecule is used for very reactive species, i. e, according to Merriam-Webster and the Online Etymology Dictionary, the word molecule derives from the Latin moles or small unit of mass. Molecule – extremely minute particle, from French molécule, from New Latin molecula, diminutive of Latin moles mass, a vague meaning at first, the vogue for the word can be traced to the philosophy of Descartes. The definition of the molecule has evolved as knowledge of the structure of molecules has increased, earlier definitions were less precise, defining molecules as the smallest particles of pure chemical substances that still retain their composition and chemical properties. Molecules are held together by covalent bonding or ionic bonding. Several types of non-metal elements exist only as molecules in the environment, for example, hydrogen only exists as hydrogen molecule. A molecule of a compound is made out of two or more elements, a covalent bond is a chemical bond that involves the sharing of electron pairs between atoms
Molecule
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Atomic force microscopy image of a
PTCDA molecule, which contains five carbon rings in a non-linear arrangement.
Molecule
Molecule
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A
scanning tunneling microscopy image of
pentacene molecules, which consist of linear chains of five carbon rings.
Molecule
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Arrangement of
polyvinylidene fluoride molecules in a
nanofiber –
transmission electron microscopy image.
6.
Immunological memory
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Immunity is the capability of multicellular organisms to resist harmful microorganisms from entering it. Immunity involves both specific and nonspecific components, the nonspecific components act as barriers or eliminators of a wide range of pathogens irrespective of their antigenic make-up. Other components of the immune system adapt themselves to each new disease encountered and are able to generate pathogen-specific immunity, an immune system may contain innate and adaptive components. The innate system in mammalians for example is composed of bone marrow cells that are programmed to recognise foreign substances. The adaptive system is composed of more advanced lymphatic cells that are programmed to recognise self substances, the reaction to foreign substances is etymologically described as inflammation, meaning to set on fire. The non-reaction to self substances is described as immunity, meaning to exempt or as immunotolerance, disease can arise when what is foreign cannot be eliminated or what is self is not spared. Innate immunity, also called native immunity, exists by virtue of an organisms constitution and it is divided into two types, Non-Specific innate immunity, a degree of resistance to all infections in general. Specific innate immunity, a resistance to a kind of microorganism only. As a result some races, specific individuals or breeds in agriculture do not suffer from certain infectious diseases, passive immunity is acquired through transfer of antibodies or activated T-cells from an immune host, it is short lived—usually lasting only a few months. The diagram below summarizes these divisions of immunity, humoral immunity is called active when the organism generates its own antibodies, and passive when antibodies are transferred between individuals or species. Similarly, cell mediated immunity is active when the organisms’ own T-cells are stimulated, the concept of immunity has intrigued mankind for thousands of years. Between the time of Hippocrates and the 19th century, when the foundations of the methods were laid. If someone were exposed to the miasma in a swamp, in evening air, or breathing air in a sickroom or hospital ward, the modern word immunity derives from the Latin immunis, meaning exemption from military service, tax payments or other public services. For no one was attacked a second time, or not with a fatal result. The term immunes, is found in the epic poem Pharsalia written around 60 B. C. by the poet Marcus Annaeus Lucanus to describe a North African tribes resistance to snake venom. In the treatise, Al Razi describes the presentation of smallpox. The first scientist who developed full theory of immunity was Ilya Mechnikov after he revealed phagocytosis in 1882, the birth of active immunotherapy may have begun with Mithridates VI of Pontus. To induce active immunity for snake venom, he recommended using a similar to modern toxoid serum therapy
Immunological memory
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A representation of the
cholera epidemic of the nineteenth century.
Immunological memory
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Scheme of a
Fc receptor
Immunological memory
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Louis Pasteur in his laboratory, 1885.
Immunological memory
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One of the first bottles of
diphtheria antitoxin produced (Dated 1895).
7.
Adaptive immune system
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The adaptive immune system is one of the two main immunity strategies found in vertebrates. Adaptive immunity creates immunological memory after a response to a specific pathogen. This process of acquired immunity is the basis of vaccination, like the innate system, the adaptive system includes both humoral immunity components and cell-mediated immunity components. Unlike the innate system, the adaptive immune system is highly specific to a particular pathogen. Adaptive immunity can also provide long-lasting protection, for example, someone who recovers from measles is now protected against measles for their lifetime, in other cases it does not provide lifetime protection, for example, chickenpox. The adaptive system response destroys invading pathogens and any toxic molecules they produce, sometimes the adaptive system is unable to distinguish harmful from harmless foreign molecules, the effects of this may be hayfever, asthma or any other allergy. Antigens are any substances that elicit the immune response. The cells that carry out the immune response are white blood cells known as lymphocytes. Two main broad classes—antibody responses and cell mediated immune response—are also carried by two different lymphocytes, in antibody responses, B cells are activated to secrete antibodies, which are proteins also known as immunoglobulins. Antibodies travel through the bloodstream and bind to the foreign antigen causing it to inactivate, in acquired immunity, pathogen-specific receptors are acquired during the lifetime of the organism. The acquired response is called adaptive because it prepares the immune system for future challenges. The system is highly adaptable because of somatic hypermutation, and VJ recombination and this mechanism allows a small number of genes to generate a vast number of different antigen receptors, which are then uniquely expressed on each individual lymphocyte. A theoretical framework explaining the workings of the immune system is provided by immune network theory. This theory, which builds on established concepts of clonal selection, is being applied in the search for an HIV vaccine, the major functions of the adaptive immune system include, Recognition of specific non-self antigens in the presence of self, during the process of antigen presentation. Generation of responses that are tailored to eliminate specific pathogens or pathogen-infected cells. Development of immunological memory, in which pathogens are remembered through memory B cells, the cells of the adaptive immune system are T and B lymphocytes, lymphocytes are a subset of leukocyte. B cells and T cells are the types of lymphocytes. The human body has about 2 trillion lymphocytes, constituting 20–40% of white blood cells, the peripheral blood contains 2% of circulating lymphocytes, the rest move within the tissues and lymphatic system
Adaptive immune system
–
A
scanning electron microscope (SEM) image of a single human
lymphocyte
8.
T cell
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A T cell, or T lymphocyte, is a type of lymphocyte that plays a central role in cell-mediated immunity. T cells can be distinguished from other lymphocytes, such as B cells and natural killer cells and they are called T cells because they mature in the thymus from thymocytes. The several subsets of T cells each have a distinct function, the majority of human T cells rearrange their alpha and beta chains on the cell receptor and are termed alpha beta T cells and are part of the adaptive immune system. The category of effector T cell is a one that includes various T cell types that actively respond to a stimulus. This includes helper, killer, regulatory, and potentially other T cell types, T helper cells assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages. These cells are known as CD4+ T cells because they express the CD4 glycoprotein on their surfaces. Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, once activated, they divide rapidly and secrete small proteins called cytokines that regulate or assist in the active immune response. These cells can differentiate one of several subtypes, including TH1, TH2, TH3, TH17, TH9, or TFH. Signalling from the APC directs T cells into particular subtypes, cytotoxic T cells destroy virus-infected cells and tumor cells, and are also implicated in transplant rejection. These cells are known as CD8+ T cells since they express the CD8 glycoprotein at their surfaces. These cells recognize their targets by binding to antigen associated with MHC class I molecules, through IL-10, adenosine, and other molecules secreted by regulatory T cells, the CD8+ cells can be inactivated to an anergic state, which prevents autoimmune diseases. Appropriate co-stimulation must be present at the time of encounter for this process to occur. Historically, memory T cells were thought to belong to either the effector or central memory subtypes, subsequently, numerous new populations of memory T cells were discovered including tissue-resident memory T cells, stem memory TSCM cells, and virtual memory T cells. The single unifying theme for all memory T cell subtypes is that they are long-lived, by this mechanism they provide the immune system with memory against previously encountered pathogens. Memory T cells may be either CD4+ or CD8+ and usually express CD45RO, memory T cell subtypes, Central memory T cells express CD45RO, C-C chemokine receptor type 7, and L-selectin. Central memory T cells also have intermediate to high expression of CD44 and this memory subpopulation is commonly found in the lymph nodes and in the peripheral circulation. Effector memory T cells express CD45RO but lack expression of CCR7 and they also have intermediate to high expression of CD44. These memory T cells lack lymph node-homing receptors and are found in the peripheral circulation
T cell
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Scanning electron micrograph of a human T cell
T cell
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Scanning electron micrograph of T lymphocyte (right), a
platelet (center) and a
red blood cell (left)
9.
B cell
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B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the immune system by secreting antibodies. Additionally, B cells present antigen and secrete cytokines, in mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricius, B cells, unlike the other two classes of lymphocytes, T cells and natural killer cells, express B cell receptors on their cell membrane. BCRs allow the B cell to bind a specific antigen, against which it will initiate an antibody response, B cells develop from hematopoietic stem cells that originate from bone marrow. HSCs first differentiate into multipotent progenitor cells, then common lymphoid progenitor cells, B cells undergo two types of selection while developing in the bone marrow to ensure proper development. Positive selection occurs through antigen-independent signaling involving both the pre-BCR and the BCR, if these receptors do not bind to their ligand, B cells do not receive the proper signals and cease to develop. This negative selection process leads to a state of central tolerance, to complete development, immature B cells migrate from the bone marrow to the spleen as well as pass through two transitional stages, T1 and T2. Throughout their migration to the spleen and after spleen entry, they are considered T1 B cells, within the spleen, T1 B cells transition to T2 B cells. T2 B cells differentiate into either follicular B cells or marginal zone B cells depending on signals received through the BCR, once differentiated, they are now considered mature B cells, or naive B cells. While immature and during the T1 phase, B cells express BCRCR of class IgH, B cell activation occurs in the secondary lymphoid organs, such as the spleen and lymph nodes. After B cells mature in the marrow, they migrate through the blood to SLOs. At the SLO, B cell activation begins when the B cell binds to an antigen via its BCR, antigen is presented to lymphocytes by APCs such as macrophages or dendritic cells, and include proteins, glycoproteins, polysaccharides, whole virus particles, and whole bacterial cells. Of the three B cell subsets, FO B cells preferentially undergo T cell-dependent activation while MZ B cells, B cell activation is enhanced through the activity of CD21, a surface receptor in complex with surface proteins CD19 and CD81. Antigens that activate B cells with the help of T-cell are known as T cell-dependent antigens and they are named as such because they are unable to induce a humoral response in organisms that lack T cells. B cell response to these antigens takes multiple days, though antibodies generated have an affinity and are more functionally versatile than those generated from T cell-independent activation. T helper cells, typically follicular T helper cells, that were activated with the same antigen recognize, following TCR-MHC-II-peptide binding, T cells express the surface protein CD40L as well as cytokines such as IL-4 and IL-21. T cell-derived cytokines bound by B cell cytokine receptors also promote B cell proliferation, immunoglobulin class switching, after B cells receive these signals, they are considered activated
B cell
10.
Antibody
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An antibody, also known as an immunoglobulin, is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as bacteria and viruses. The antibody recognizes a molecule of the harmful agent, called an antigen. Each tip of the Y of an antibody contains a paratope that is specific for one particular epitope on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or a cell for attack by other parts of the immune system. Depending on the antigen, the binding may impede the process causing the disease or may activate macrophages to destroy the foreign substance. The ability of an antibody to communicate with the components of the immune system is mediated via its Fc region. The production of antibodies is the function of the humoral immune system. Antibodies are secreted by B cells of the immune system. In most cases, interaction of the B cell with a T helper cell is necessary to produce full activation of the B cell and, therefore, soluble antibodies are released into the blood and tissue fluids, as well as many secretions to continue to survey for invading microorganisms. Antibodies are glycoproteins belonging to the immunoglobulin superfamily and they constitute most of the gamma globulin fraction of the blood proteins. They are typically made of basic structural units—each with two heavy chains and two small light chains. There are several different types of heavy chains that define the five different types of crystallisable fragments that may be attached to the antigen-binding fragments. The five different types of Fc regions allow antibodies to be grouped into five isotypes, each Fc region of a particular antibody isotype is able to bind to its specific Fc Receptor, thus allowing the antigen-antibody complex to mediate different roles depending on which FcR it binds. The ability of an antibody to bind to its corresponding FcR is further modulated by the structure of the present at conserved sites within its Fc region. The ability of antibodies to bind to FcRs helps to direct the immune response for each different type of foreign object they encounter. For example, IgE is responsible for an allergic response consisting of mast cell degranulation, igEs Fab paratope binds to allergic antigen, for example house dust mite particles, while its Fc region binds to Fc receptor ε. The allergen-IgE-FcRε interaction mediates allergic signal transduction to induce conditions such as asthma and this region is known as the hypervariable region. Each of these variants can bind to a different antigen and this enormous diversity of antibody paratopes on the antigen-binding fragments allows the immune system to recognize an equally wide variety of antigens
Antibody
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Immunofluorescence image of the eukaryotic
cytoskeleton.
Actin filaments are shown in red,
microtubules in green, and the
nuclei in blue.
Antibody
–
Each antibody binds to a specific
antigen; an interaction similar to a lock and key.
Antibody
–
Example of tissue cross-reactivity on human
tissue microarray
Antibody
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Angel of the West (2008) by
Julian Voss-Andreae is a sculpture based on the antibody structure published by E. Padlan. Created for the Florida campus of
the Scripps Research Institute, the antibody is placed into a ring referencing
Leonardo da Vinci's Vitruvian Man thus highlighting the similarity of the antibody and the human body.
11.
Memory B cell
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Activated B cells that fail to undergo germinal center differentiation do not persist as effective memory B cells and are rapidly negatively selected against. Within germinal centers, B cells proliferate and mutate the genetic coding for their surface antibody. The process is called somatic hypermutation and is responsible for introducing spontaneous mutations with a frequency of about 1 in every 1600 cell division, then after gaining a set number of mutations, germinal center B cells are subjected to a round of selection by TFH cells. Thus, an antibody response having improved affinity towards antigen is typically observed in the secondary immune response. It is unclear at what stage such a model reaches saturation to provide a level of antibody-mediated immune protection against the same antigen
Memory B cell
–
B lymphocytes are the cells of the immune system that make antibodies to invading pathogens like viruses. They form memory cells that remember the same pathogen for faster antibody production in future infections.
12.
Memory T cell
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Such T cells can recognize foreign invaders, such as bacteria or viruses, as well as cancer cells. Memory T cells have become experienced by having encountered antigen during an infection, encounter with cancer. At a second encounter with the invader, memory T cells can reproduce to mount a faster and stronger immune response than the first time the system responded to the invader. This behaviour is utilized in T lymphocyte proliferation assays, which can reveal exposure to specific antigens, within the overall memory T cell population, at least three distinct subpopulations have been described and can be recognised by the differential expression of chemokine receptor CCR7 and L-selectin. Central memory TCM cells express L-selectin and the CCR7, they secrete IL-2, effector memory TEM cells, however, do not express L-selectin or CCR7 but produce effector cytokines like IFNγ and IL-4. In mouse, this population would be highly expressive of CD44, more recently, other sub-populations have been explored using co-stimulatory molecules CD27 and CD28 expression in addition to CCR7 and CD62L. Those peripheral tissues are the skin, gut and joints, and are thought to be a key source of the immune systems protective memory, dysfunctional TRM cells are strongly implicated in autoimmune diseases, such as psoriasis, rheumatoid arthritis, inflammatory bowel disease. Specific to TRMs are genes involved in metabolism, being highly active. Antigen-specific memory T cells against viruses or other molecules can be found in both TCM and TEM subsets. Although most information is based on observations in the cytotoxic T cells subset. The TCM cells are thought to some properties associated with memory cells stem cells. TCM display a capacity for self-renewal due to levels of phosphorylation of an important transcription factor known as STAT5. In mice, TCM cells have shown to confer superior protection against viruses, bacteria. This population, now termed stem cell memory, can be identified by the markers CD44CD62LCD122sca-1 and are capable of generating TCM, in preclinical studies, adoptively transferred TSCM confer superior immunity compared with other T memory subsets. Whether such a population is found in humans is the subject of active investigation, naive T cell VJ recombination of DNA Memory B cell Janeway, Charles. Immunobiology, the system in health and disease. Lichtman, Andrew H. Abbas, Abul K
Memory T cell
–
A
lymphocyte is shown in the center of this picture
Memory T cell
13.
Passive immunization
–
Passive immunity is the transfer of active humoral immunity in the form of ready-made antibodies. Passive immunization can be provided when people cannot synthesize antibodies, maternal passive immunity is a type of naturally acquired passive immunity, and refers to antibody-mediated immunity conveyed to a fetus or infant by its mother. Naturally acquired passive immunity can be provided during pregnancy, and through breast-feeding, in humans, maternal antibodies are passed through the placenta to the fetus by an FcRn receptor on placental cells. This occurs predominately during the third trimester of pregnancy, and thus is reduced in babies born prematurely. Immunoglobulin G is the only isotype that can pass through the human placenta. IgG antibodies protects against bacterial and viral infections in fetuses and this effect is usually overcome by secondary responses to booster immunization. Maternal antibodies protect against some diseases more than such as measles, rubella, and tetanus compared to the protection provided against polio. Maternal passive immunity offers immediate protection, though protection mediated by maternal IgG typically only lasting four to six months after birth, only a few other species besides humans transfer maternal antibodies before birth, including primates and lagomorphs. In some of these species IgM can be transferred across the placenta as well as IgG, all other mammalian species predominantly or solely transfer maternal antibodies after birth through milk. In these species, the gut is able to absorb IgG for hours to days after birth. However, after a period of time the neonate can no longer absorb maternal IgG through their gut, an event that is referred to as gut closure. If a neonatal animal does not receive adequate amounts of colostrum prior to gut closure, is does not have a sufficient amount of maternal IgG in its blood to fight off common diseases and this condition is referred to as failure of passive transfer. It can be diagnosed by measuring the amount of IgG in a newborns blood, if not treated, it can be fatal. Passive transfer is used to prevent disease or used prophylactically in the case of immunodeficiency diseases and it is also used in the treatment of several types of acute infection, and to treat poisoning. Immunity derived from passive immunization lasts for a few weeks to three to four months, there is also a potential risk for hypersensitivity reactions, and serum sickness, especially from gamma globulin of non-human origin. By 1896, the introduction of diphtheria antitoxin was hailed as the most important advance of the Century in the treatment of acute infective disease. Prior to the advent of vaccines and antibiotics, specific antitoxin was often the treatment available for infections such as diphtheria. Immunoglobulin therapy continued to be a first line therapy in the treatment of respiratory diseases until the 1930s
Passive immunization
–
A vial of diphtheria antitoxin, dated 1895
14.
Vaccination
–
Vaccination is the administration of antigenic material to stimulate an individuals immune system to develop adaptive immunity to a pathogen. Vaccines can prevent or ameliorate morbidity from infection, when a sufficiently large percentage of a population has been vaccinated, this results in herd immunity. The effectiveness of vaccination has been studied and verified, for example, the influenza vaccine, the HPV vaccine. The World Health Organization reports that licensed vaccines are available to prevent or contribute to the prevention. The active agent of a vaccine may be intact but inactivated or attenuated forms of the causative pathogens, toxoids are produced for immunization against toxin-based diseases, such as the modification of tetanospasmin toxin of tetanus to remove its toxic effect but retain its immunogenic effect. Smallpox was most likely the first disease people tried to prevent by inoculating themselves and was the first disease for which a vaccine was produced, Louis Pasteur furthered the concept through his work in microbiology. The immunization was called vaccination because it was derived from a virus affecting cows, smallpox was a contagious and deadly disease, causing the deaths of 20–60% of infected adults and over 80% of infected children. When smallpox was finally eradicated in 1979, it had killed an estimated 300–500 million people in the 20th century. In common speech, vaccination and immunization have a similar meaning and this distinguishes it from inoculation, which uses unweakened live pathogens, although in common usage either can refer to an immunization. Vaccination efforts have met with some controversy on scientific, ethical, political, medical safety. In rare cases, vaccinations can injure people and, in the United States, early success and compulsion brought widespread acceptance, and mass vaccination campaigns have greatly reduced the incidence of many diseases in numerous geographic regions. Generically, the process of induction of immunity, in an effort to protect against infectious disease. Stimulating immune responses with an agent is known as immunization. Vaccination includes various ways of administering immunogens, some vaccines are administered after the patient already has contracted a disease. The first rabies immunization was given by Louis Pasteur to a child after he was bitten by a rabid dog, other examples include experimental AIDS, cancer and Alzheimers disease vaccines. Such immunizations aim to trigger a response more rapidly and with less harm than natural infection. Most vaccines are given by injection as they are not absorbed reliably through the intestines. Live attenuated polio, some typhoid, and some cholera vaccines are given orally to produce immunity in the bowel, while vaccination provides a lasting effect, it usually takes several weeks to develop, while passive immunity has immediate effect
Vaccination
–
Child receiving an
oral polio vaccine
Vaccination
–
Polio vaccination started in Sweden in 1957.
Vaccination
–
Jenner's handwritten draft of the first vaccination
Vaccination
–
A doctor performing a
typhoid vaccination in
Texas, 1943
15.
Microorganism
–
A microorganism or microbe is a microscopic organism, which may be single-celled or multicellular. The study of microorganisms is called microbiology, a subject that began with the discovery of microorganisms in 1674 by Antonie van Leeuwenhoek, microorganisms are very diverse and include all bacteria, archaea and most protozoa. This group also contains some fungi, algae, and some such as rotifers. Many macroscopic animals and plants have microscopic juvenile stages, some microbiologists classify viruses and viroids as microorganisms, but others consider these as nonliving. In July 2016, scientists identified a set of 355 genes from the last universal ancestor of all life, including microorganisms. Microorganisms, under certain test conditions, have observed to thrive in the vacuum of outer space. Microorganisms likely far outweigh all other living things combined, the mass of prokaryote microorganisms including the bacteria and archaea may be as much as 0.8 trillion tons of carbon, out of the total biomass of between 1 and 4 trillion tons. Microorganisms appear to thrive in the Mariana Trench, the deepest spot in the Earths oceans, in August 2014, scientists confirmed the existence of microorganisms living 800 m below the ice of Antarctica. According to one researcher, You can find microbes everywhere — theyre extremely adaptable to conditions, microorganisms are crucial to nutrient recycling in ecosystems as they act as decomposers. As some microorganisms can fix nitrogen, they are a part of the nitrogen cycle. Microorganisms are also exploited in biotechnology, both in food and beverage preparation, and in modern technologies based on genetic engineering. A small proportion of microorganisms are pathogenic, causing disease and even death in plants, Robert Hooke coined the term cell after viewing plant cells under his microscope. Antonie Van Leeuwenhoek was one of the first people to observe microorganisms in 1673, later, in the 19th century, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In 1876 Robert Koch discovered that microorganisms cause diseases, single-celled microorganisms were the first forms of life to develop on Earth, approximately 3–4 billion years ago. Further evolution was slow, and for about 3 billion years in the Precambrian eon, so, for most of the history of life on Earth, the only forms of life were microorganisms. Bacteria, algae and fungi have been identified in amber that is 220 million years old, microorganisms tend to have a relatively fast rate of evolution. Most microorganisms can reproduce rapidly, and bacteria are able to freely exchange genes through conjugation, transformation and transduction. This rapid evolution is important in medicine, as it has led to the development of multidrug resistant pathogenic bacteria, superbugs, the possible existence of microorganisms was discussed for many centuries before their discovery in the 17th century
Microorganism
–
A cluster of
Escherichia coli bacteria magnified 10,000 times
Microorganism
–
Antonie van Leeuwenhoek, the first
microbiologist and the first to observe microorganisms using a
microscope
Microorganism
–
Lazzaro Spallanzani showed that boiling a broth stopped it from decaying
Microorganism
–
Louis Pasteur showed that Spallanzani's findings held even if air could enter through a filter that kept particles out
16.
Disease
–
A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the study of cause, Disease is often construed as a medical condition associated with specific symptoms and signs. When caused by pathogens, even in the literature, the term disease is often misleadingly used in the place of its causal agent. This language habitat can cause confusion in the communication of the principle in epidemiology. Diseases can affect not only physically, but also emotionally. Death due to disease is called death by natural causes, there are four main types of disease, infectious diseases, deficiency diseases, genetic diseases, and physiological diseases. Diseases can also be classified as communicable and non-communicable, the deadliest diseases in humans are coronary artery disease, followed by cerebrovascular disease and lower respiratory infections. In many cases, terms such as disease, disorder, morbidity, there are situations, however, when specific terms are considered preferable. Disease The term disease broadly refers to any condition that impairs the normal functioning of the body, for this reason, diseases are associated with dysfunctioning of the bodys normal homeostatic processes. The term disease has both a count sense and a noncount sense, by contrast, an infection that is asymptomatic during its incubation period, but expected to produce symptoms later, is usually considered a disease. Non-infectious diseases are all other diseases, including most forms of cancer, heart disease, acquired disease disease that began at some point during ones lifetime, as opposed to disease that was already present at birth, which is congenital disease. Acquired sounds like it could mean caught via contagion, but it simply means acquired sometime after birth and it also sounds like it could imply secondary disease, but acquired disease can be primary disease. It is often, genetic and can be inherited and it can also be the result of a vertically transmitted infection from the mother such as HIV/AIDS. Genetic disease disease that is caused by genetic mutation and it is often inherited, but some mutations are random and de novo. Hereditary or inherited disease a type of disease caused by mutation that is hereditary Iatrogenic disease A disease condition caused by medical intervention. Idiopathic disease disease whose cause is unknown, as medical science has advanced, many diseases whose causes were formerly complete mysteries have been somewhat explained or even extensively explained. Bacterial infections can be primary or secondary to a viral infection or burn. Terminal disease disease with death as an inevitable result Illness Illness is generally used as a synonym for disease, however, this term is occasionally used to refer specifically to the patients personal experience of his or her disease
Disease
–
Scanning electron micrograph of
Mycobacterium tuberculosis, a
bacterium that causes
tuberculosis.
Disease
–
Obesity was a status symbol in
Renaissance culture: "The Tuscan General
Alessandro del Borro ", attributed to
Andrea Sacchi, 1645. It is now generally regarded as a disease.
17.
Mutation
–
In biology, a mutation is the permanent alteration of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements. Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements, mutations may or may not produce discernible changes in the observable characteristics of an organism. Mutations play a part in normal and abnormal biological processes including, evolution, cancer, and the development of the immune system. The genomes of RNA viruses are based on RNA rather than DNA, the RNA viral genome can be double stranded or single stranded. In some of these viruses replication occurs quickly and there are no mechanisms to check the genome for accuracy and this error-prone process often results in mutations. Mutation can result in different types of change in sequences. Mutations in genes can either have no effect, alter the product of a gene, mutations can also occur in nongenic regions. Mutations can involve the duplication of large sections of DNA, usually through genetic recombination and these duplications are a major source of raw material for evolving new genes, with tens to hundreds of genes duplicated in animal genomes every million years. Most genes belong to larger families of shared ancestry, known as homology. Here, protein domains act as modules, each with a particular and independent function, that can be mixed together to produce genes encoding new proteins with novel properties. For example, the eye uses four genes to make structures that sense light. Another advantage of duplicating a gene is that this increases engineering redundancy, other types of mutation occasionally create new genes from previously noncoding DNA. Changes in chromosome number may involve even larger mutations, where segments of the DNA within chromosomes break and then rearrange. For example, in the Homininae, two fused to produce human chromosome 2, this fusion did not occur in the lineage of the other apes. Sequences of DNA that can move about the genome, such as transposons, make up a fraction of the genetic material of plants and animals. For example, more than a million copies of the Alu sequence are present in the genome. Another effect of these mobile DNA sequences is that when they move within a genome, they can mutate or delete existing genes, nonlethal mutations accumulate within the gene pool and increase the amount of genetic variation. The abundance of some changes within the gene pool can be reduced by natural selection, while other more favorable mutations may accumulate
Mutation
–
A mutation has caused this garden
moss rose to produce flowers of different colors. This is a
somatic mutation that may also be passed on in the
germline.
Mutation
–
Diagrammatic representation of the
divergence of modern
taxonomic groups from their
common ancestor
18.
Cell (biology)
–
The cell is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life that can replicate independently, the study of cells is called cell biology. Cells consist of cytoplasm enclosed within a membrane, which contains many such as proteins. Organisms can be classified as unicellular or multicellular, while the number of cells in plants and animals varies from species to species, humans contain more than 10 trillion cells. Most plant and animal cells are only under a microscope. The cell was discovered by Robert Hooke in 1665, who named the unit for its resemblance to cells inhabited by Christian monks in a monastery. Cells emerged on Earth at least 3.5 billion years ago, Cells are of two types, eukaryotic, which contain a nucleus, and prokaryotic, which do not. Prokaryotes are single-celled organisms, while eukaryotes can be either single-celled or multicellular, prokaryotic cells were the first form of life on Earth, characterised by having vital biological processes including cell signaling and being self-sustaining. They are simpler and smaller than eukaryotic cells, and lack membrane-bound organelles such as the nucleus, prokaryotes include two of the domains of life, bacteria and archaea. The DNA of a prokaryotic cell consists of a chromosome that is in direct contact with the cytoplasm. The nuclear region in the cytoplasm is called the nucleoid, most prokaryotes are the smallest of all organisms ranging from 0.5 to 2.0 µm in diameter. Though most prokaryotes have both a cell membrane and a wall, there are exceptions such as Mycoplasma and Thermoplasma which only possess the cell membrane layer. The envelope gives rigidity to the cell and separates the interior of the cell from its environment, the cell wall consists of peptidoglycan in bacteria, and acts as an additional barrier against exterior forces. It also prevents the cell from expanding and bursting from osmotic pressure due to a hypotonic environment, some eukaryotic cells also have a cell wall. Inside the cell is the region that contains the genome, ribosomes. The genetic material is found in the cytoplasm. Prokaryotes can carry extrachromosomal DNA elements called plasmids, which are usually circular, linear bacterial plasmids have been identified in several species of spirochete bacteria, including members of the genus Borrelia notably Borrelia burgdorferi, which causes Lyme disease. Though not forming a nucleus, the DNA is condensed in a nucleoid, plasmids encode additional genes, such as antibiotic resistance genes
Cell (biology)
–
Onion (
Allium) cells in different phases of the cell cycle
Cell (biology)
–
Structure of an animal cell
Cell (biology)
–
A fluorescent image of an endothelial cell. Nuclei are stained blue,
mitochondria are stained red, and microfilaments are stained green.
Cell (biology)
–
Human cancer cells with nuclei (specifically the DNA) stained blue. The central and rightmost cell are in
interphase, so the entire nuclei are labeled. The cell on the left is going through
mitosis and its DNA has condensed.
19.
Nicotine
–
Nicotine is a potent parasympathomimetic stimulant and an alkaloid found in the nightshade family of plants. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors, Nicotine is found in the leaves of Nicotiana rustica in amounts of 2–14%, the tobacco plant Nicotiana tabacum, Duboisia hopwoodii and Asclepias syriaca. Nicotine constitutes approximately 0. 6–3. 0% of the dry weight of tobacco, less than one millionth of that concentration is found in edible Solanaceae such as eggplants and tomatoes. It functions as a chemical, consequently, nicotine was widely used as an insecticide in the past. An average cigarette yields about 2 mg of absorbed nicotine, and in lesser doses of that order and this stimulant effect is a contributing factor to the addictive properties of tobacco smoking. Nicotines addictive nature includes psychoactive effects, drug-reinforced behavior, compulsive use, relapse after abstinence, beyond addiction, both short and long-term nicotine exposure have not been established as dangerous to adults, except among certain vulnerable groups. At high-enough doses, nicotine is associated with poisonings and is potentially lethal, Nicotine as a tool for quitting smoking has a good safety history. There is inadequate research to show that nicotine itself is associated with cancer in humans, Nicotine in the form of nicotine replacement products is less of a cancer risk than smoking. Nicotine is linked to birth defects. During pregnancy, there are risks to the later in life for type 2 diabetes, obesity, hypertension, neurobehavioral defects, respiratory dysfunction. Nicotines mood-altering effects are different by report, in particular it is both a stimulant and a relaxant, first causing a release of glucose from the liver and epinephrine from the adrenal medulla, it causes stimulation. Users report feelings of relaxation, sharpness, calmness, and alertness, like any stimulant, it may very rarely cause the often uncomfortable akathisia. By reducing the appetite and raising the metabolism, some smokers may lose weight as a consequence, Nicotine also extends the duration of positive effects of dopamine and increases the sensitivity of the brains reward system to rewarding stimuli. Most cigarettes contain 1–3 milligrams of inhalable nicotine, studies suggest that when smokers wish to achieve a stimulating effect, they take short quick puffs, which produce a low level of blood nicotine. At very high doses it dampens neuronal activity, the primary therapeutic use of nicotine is in treating nicotine dependence in order to eliminate smoking with the damage it does to health. Controlled levels of nicotine are given to patients through gums, dermal patches, lozenges, studies have found that these therapies increase the chance of success of quitting by 50 to 70%, though reductions in the population as a whole have not been demonstrated. Nicotine is frequently used for its effects on cognition, alertness. Nicotine is commonly consumed as a drug for its stimulant effects
Nicotine
–
A 21 mg patch applied to the left arm. The
Cochrane Collaboration finds that
nicotine replacement therapy increases a quitter's chance of success by 50% to 70%.
Nicotine
–
Nicotine
Nicotine
–
Types
20.
Ghrelin
–
Besides regulating appetite, ghrelin also plays a significant role in regulating the distribution and rate of use of energy. When the stomach is empty, ghrelin is secreted, Ghrelin is encoded by the GHRL gene and is presumably produced from the cleavage of the prepropeptide ghrelin/obestatin. Full-length preproghrelin is homologous to promotilin and both are members of the motilin family, unlike the case of many other endogenous peptides, ghrelin is able to cross the blood-brain-barrier, giving exogenously-administered ghrelin unique clinical potential. Ghrelin was discovered after the ghrelin receptor was discovered in 1996 and was reported in 1999, the hormone name is based on its role as a growth hormone-releasing peptide, with reference to the Proto-Indo-European root ghre-, meaning to grow. The GHRL gene produces mRNA which has four exons, five products arise, the first is the 117-amino acid preproghrelin. It is cleaved to produce proghrelin which is cleaved to produce a 28-amino acid ghrelin and C-ghrelin, obestatin is presumed to be cleaved from C-ghrelin. Ghrelin only becomes active when caprylic acid is linked posttranslationally to serine at the 3-position by the enzyme ghrelin O-acyltransferase and it is located on the cell membrane of ghrelin cells in the stomach and pancreas. The non-octanoylated form is desacyl ghrelin, in particular, decanoyl ghrelin has been found to constitute a significant portion of circulating ghrelin in mice, but as of 2011 its presence in humans has not been established. The ghrelin cell is known as an A-like cell, X-cell, X/A-like cell, Epsilon cell, P/D sub 1 cell. Ghrelin cells are mainly in the stomach and duodenum, but also in the jejunum, lungs, pancreatic islets, gonads, adrenal cortex, placenta. It has recently shown that ghrelin is produced locally in the brain Ghrelin cells are found in oxyntic glands, pyloric glands. They are ovoid cells with granules, Ghrelin cells are not terminally differentiated in the pancreas, they are progenitor cells that can give rise to A-cells, PP cells and Beta-cells there. The net result of processes is reflected in body weight. At any given moment in time, it may be in equilibrium or disequilibrium, Ghrelin and synthetic ghrelin mimetics increase body weight and fat mass by triggering receptors in the arcuate nucleus that include the orexigenic neuropeptide Y and agouti-related protein neurons. Ghrelin-responsiveness of these neurons is both leptin- and insulin-sensitive, Ghrelin reduces the mechanosensitivity of gastric vagal afferents, so they are less sensitive to gastric distension. Ghrelin receptors are located on neurons in this circuit, hypothalamic ghrelin signalling is required for reward from alcohol and palatable/rewarding foods. Ghrelin also improves endothelial function and inhibits proatherogenic changes in cell cultures and it activates the endothelial isoform of nitric oxide synthase in a pathway that depends on various kinases including Akt. Ghrelin has been linked to inducing appetite and feeding behaviors, circulating ghrelin levels are the highest right before a meal and the lowest right after
Ghrelin
–
Preproghrelin (green and blue) and ghrelin (green).
21.
Inoculation
–
The terms inoculation, vaccination, immunization and injection are often used synonymously to refer to artificial induction of immunity against various infectious diseases. This is supported by some dictionaries, however, there are some important historical and current differences. In English medicine, inoculation referred only to the prevention of smallpox until the very early 1800s, when Edward Jenner introduced smallpox vaccine in 1798, this was initially called cowpox inoculation or vaccine inoculation. Soon, to avoid confusion, smallpox inoculation was referred to as variolation, then, in 1891 Louis Pasteur proposed that the terms vaccine and vaccination should be extended to include the new protective procedures being developed. Immunization refers to the use of all vaccines but also extends to the use of antitoxin, Inoculation is now more or less synonymous in nontechnical usage with injection etc. and the question e. g. Have you had your flu injection/vaccination/inoculation/immunization, the focus is on what is being given and why, not the literal meaning of the technique used. Inoculation also has a meaning for procedures done in vitro. In almost all cases the material inoculated is called the inoculum, or less commonly the inoculant, the term inoculation entered medical English through horticultural usage meaning to graft a bud from one plant into another. It is derived from the Latin in + oculus, though innoculation/innoculate is sometimes seen, this is incorrect, possibly erroneously thought to be related to innocuous, which is derived from the Latin in + nocuus. Inoculation originated as a method for the prevention of smallpox by deliberate introduction of material from smallpox pustules into the skin and this generally produced a less severe infection than naturally-acquired smallpox, but still induced immunity to it. This first method for smallpox prevention, smallpox inoculation, is now known as variolation. The earliest hints of the practice of inoculation for smallpox in China come during the 10th century, however, the sinologist Joseph Needham states that this information comes from the Zhongdou xinfa written in 1808 by Zhu Yiliang, centuries after the alleged events. Inoculation was first vividly described by Yu Chang in his book Yuyi cao, or Notes on My Judgment and this was called to implant the sprouts, an idea of transplanting the disease which fit their conception of beansprouts in germination. Wrap the scabs carefully in paper and put them into a small container bottle, cork it tightly so that the activity is not dissipated. The container must not be exposed to sunlight or warmed beside a fire and it is best to carry it for some time on the person so that the scabs dry naturally and slowly. The container should be marked clearly with the date on which the contents were taken from the patient, in winter, the material has yang potency within it, so it remains active even after being kept from thirty to forty days. But in summer the yang potency will be lost in approximately twenty days, According to Voltaire, the Turks derived their use of inoculation to neighbouring Circassia. This pustule produces the effect in the arm it is laid in as yeast in a piece of dough, it ferments
Inoculation
–
Mary Wortley Montagu, by
Charles Jervas, after 1716
Inoculation
–
Comparison of smallpox (left) and cowpox (right) inoculations 16 days after administration
22.
Lady Mary Wortley Montagu
–
Lady Mary Wortley Montagu was an English aristocrat, letter writer and poet. Aside from her writing, Lady Mary is also known for introducing and advocating for smallpox inoculation to Britain after her return from Turkey and her writings usually address and challenge the hindering contemporary social attitudes towards women and their intellectual and social growth. Lady Mary Wortley Montagu was born Mary Pierrepont in May 1689, her baptism took place on 26 May, at a few days old and she was the eldest child of Evelyn Pierrepont, 1st Duke of Kingston-upon-Hull, and his first wife, Mary Pierrepont. Her mother had three children, two girls and a boy, before dying in October 1692. The children were raised by their Pierrepont grandmother until Mary was nine years old, Lady Mary was then passed to the care of her father upon her grandmothers death. She began her education in her fathers home, family holdings were extensive, including Thoresby Hall and Holme Pierrepont Hall in Nottinghamshire, and a house in West Dean in Wiltshire. She also corresponded with two bishops, Thomas Tenison and Gilbert Burnet, by 1710 Lady Mary had two possible suitors to choose from, Edward Wortley Montagu and Clotworthy Skeffington. Lady Mary corresponded with Edward Wortley Montagu via letters from 28 March 1710 to 2 May 1711, after May 1711 there was a break in contact between Lady Mary and Edward Wortley Montagu. Marys father, now Marquess of Dorchester, rejected Wortley Montagu as a prospect because he refused to entail his estate on a possible heir and her father pressured her to marry Clotworthy Skeffington, heir to an Irish peerage. In order to avoid marriage to Skeffington, she eloped with Wortley, the marriage license is dated 17 August 1712, the marriage probably took place on 23 August 1712. The early years of Lady Mary Wortley Montagus married life were spent in the country and she had a son, Edward Wortley Montagu the younger, on 16 May 1713, in London. A couple of later, on 1 July 1713 Lady Marys brother, aged twenty, died of smallpox. On 13 October 1714, her husband accepted post as Junior Commissioner of Treasury, when Lady Mary joined him in London, her wit and beauty soon made her a prominent figure at court. In December 1715, Lady Mary contracted smallpox and she survived, but while she was ill someone circulated the satirical court eclogues she had been writing. One of the poems was read as an attack on Caroline, Princess of Wales, in 1716, Edward Wortley Montagu was appointed Ambassador at Istanbul. In August 1716, Lady Mary accompanied him to Vienna, and thence to Adrianople and he was recalled in 1717, but they remained at Istanbul until 1718. While away from England, the Wortley Montagus had a daughter on 19 January 1718, after an unsuccessful delegation between Austria and Turkey/Ottoman Empire, they set sail for England via the Mediterranean, and reached London on 2 October 1718. During her visit she was charmed by the beauty and hospitality of the Ottoman women she encountered
Lady Mary Wortley Montagu
–
A painting of Mary Wortley Montagu by Jonathan Richardson the Younger
Lady Mary Wortley Montagu
–
Mary Wortley Montagu with her son
Edward, by
Jean-Baptiste van Mour
Lady Mary Wortley Montagu
–
Mary Wortley Montagu, by
Charles Jervas, after 1716
Lady Mary Wortley Montagu
–
Alexander Pope declared his love to Lady Mary, who responded with laughter.
23.
Boston
–
Boston is the capital and most populous city of the Commonwealth of Massachusetts in the United States. Boston is also the seat of Suffolk County, although the county government was disbanded on July 1,1999. The city proper covers 48 square miles with a population of 667,137 in 2015, making it the largest city in New England. Alternately, as a Combined Statistical Area, this wider commuting region is home to some 8.1 million people, One of the oldest cities in the United States, Boston was founded on the Shawmut Peninsula in 1630 by Puritan settlers from England. It was the scene of several key events of the American Revolution, such as the Boston Massacre, the Boston Tea Party, the Battle of Bunker Hill, and the Siege of Boston. Upon U. S. independence from Great Britain, it continued to be an important port and manufacturing hub as well as a center for education, through land reclamation and municipal annexation, Boston has expanded beyond the original peninsula. Its rich history attracts many tourists, with Faneuil Hall alone drawing over 20 million visitors per year, Bostons many firsts include the United States first public school, Boston Latin School, first subway system, the Tremont Street Subway, and first public park, Boston Common. Bostons economic base also includes finance, professional and business services, biotechnology, information technology, the city has one of the highest costs of living in the United States as it has undergone gentrification, though it remains high on world livability rankings. Bostons early European settlers had first called the area Trimountaine but later renamed it Boston after Boston, Lincolnshire, England, the renaming on September 7,1630 was by Puritan colonists from England who had moved over from Charlestown earlier that year in quest of fresh water. Their settlement was limited to the Shawmut Peninsula, at that time surrounded by the Massachusetts Bay and Charles River. The peninsula is thought to have been inhabited as early as 5000 BC, in 1629, the Massachusetts Bay Colonys first governor John Winthrop led the signing of the Cambridge Agreement, a key founding document of the city. Puritan ethics and their focus on education influenced its early history, over the next 130 years, the city participated in four French and Indian Wars, until the British defeated the French and their Indian allies in North America. Boston was the largest town in British America until Philadelphia grew larger in the mid-18th century, Bostons harbor activity was significantly curtailed by the Embargo Act of 1807 and the War of 1812. Foreign trade returned after these hostilities, but Bostons merchants had found alternatives for their investments in the interim. Manufacturing became an important component of the economy, and the citys industrial manufacturing overtook international trade in economic importance by the mid-19th century. Boston remained one of the nations largest manufacturing centers until the early 20th century, a network of small rivers bordering the city and connecting it to the surrounding region facilitated shipment of goods and led to a proliferation of mills and factories. Later, a network of railroads furthered the regions industry. Boston was a port of the Atlantic triangular slave trade in the New England colonies
Boston
–
From top to bottom, left to right: the
Boston skyline viewed from the
Bunker Hill Monument; the
Museum of Fine Arts;
Faneuil Hall;
Massachusetts State House;
The First Church of Christ, Scientist;
Boston Public Library; the
John F. Kennedy Presidential Library and Museum;
South Station;
Boston University and the
Charles River;
Arnold Arboretum;
Fenway Park; and the
Boston Common
Boston
–
State Street, 1801
Boston
–
View of Boston from
Dorchester Heights, 1841
Boston
–
Scollay Square in the 1880s
24.
Edward Jenner
–
Edward Jenner, FRS was an English physician and scientist who was the pioneer of smallpox vaccine, the worlds first vaccine. The terms vaccine and vaccination are derived from Variolae vaccinae, the term devised by Jenner to denote cowpox. He used it in 1798 in the title of his Inquiry into the. Variolae vaccinae. known. the Cow Pox. Jenner is often called the father of immunology, and his work is said to have saved more lives than the work of any other human. A member of the Royal Society, in the field of zoology he was the first person to describe the brood parasitism of the cuckoo, in 2002, Jenner was named in the BBCs list of the 100 Greatest Britons. Edward Anthony Jenner was born on 17 May 1749 in Berkeley, Gloucestershire and his father, the Reverend Stephen Jenner, was the vicar of Berkeley, so Jenner received a strong basic education. He went to school in Wotton-under-Edge and Cirencester, during this time, he was inoculated for smallpox, which had a lifelong effect upon his general health. At the age of 14, he was apprenticed for seven years to Daniel Ludlow, a surgeon of Chipping Sodbury, South Gloucestershire, in 1770, Jenner became apprenticed in surgery and anatomy under surgeon John Hunter and others at St Georges Hospital. William Osler records that Hunter gave Jenner William Harveys advice, very famous in medical circles, Dont think, Hunter remained in correspondence with Jenner over natural history and proposed him for the Royal Society. Returning to his native countryside by 1773, Jenner became a family doctor and surgeon. Jenner contributed papers on angina pectoris, ophthalmia, and cardiac valvular disease and he also belonged to a similar society which met in Alveston, near Bristol. He became a mason on 30 December 1802, in Lodge of Faith. From 1812–1813, he served as master of Royal Berkeley Lodge of Faith. He described how the newly hatched cuckoo pushed its hosts eggs, the adult does not remain long enough in the area to perform this task. Jenners findings were published in Philosophical Transactions of the Royal Society in 1788, when it is about twelve days old, this cavity is quite filled up, and then the back assumes the shape of nestling birds in general. Jenners nephew assisted in the study and he was born on 30 June 1737. Jenners understanding of the behaviour was not entirely believed, until the artist Jemima Blackburn. Her description and illustration of this were enough to convince Charles Darwin to revise a later edition of On the Origin of Species, Jenner married Catherine Kingscote in March 1788
Edward Jenner
–
Edward Jenner by James Northcote
Edward Jenner
–
Memorial to Jenner in
Gloucester Cathedral
Edward Jenner
–
Common cuckoo
Edward Jenner
–
A lecturer's certificate of attendance given to Jenner. He attended many lectures on chemistry, medicine and physics.
25.
Smallpox vaccine
–
Smallpox vaccine, the first successful vaccine to be developed, was introduced by Edward Jenner in 1796. He followed up his observation that milkmaids who had previously caught cowpox did not later catch smallpox by showing that inoculated cowpox protected against inoculated smallpox. Vaccination, the term which soon replaced cowpox inoculation and vaccine inoculation, was first used in print by Jenners friend, the mortality of the severe form of smallpox—variola major—was very high without vaccination, up to 35% in some outbreaks. This is disputed, however, other investigators contend the ancient Sanskrit medical texts of India do not describe these techniques, the first clear reference to smallpox inoculation was made by the Chinese author Wan Quan in his Douzhen xinfa published in 1549. Inoculation for smallpox does not appear to have been widespread in China until the era of the Longqing Emperor during the Ming Dynasty. In China, powdered smallpox scabs were blown up the noses of the healthy, the patients would then develop a mild case of the disease and from then on were immune to it. The technique did have a 0. 5–2. 0% mortality rate, variolation was also practiced throughout the latter half of the 17th century by physicians in Turkey, Persia, and Africa. Lady Mary Wortley Montagu, wife of the British ambassador to Ottoman Constantinople, is credited with introducing the process to Great Britain in 1721. Source material tells us on Montagu, When Lady Mary was in the Ottoman Empire, in 1718 she had her son, aged five variolated. She returned to London and had her daughter variolated in 1721 by Charles Maitland and this encouraged the British Royal Family to take an interest and a trial of variolation was carried out on prisoners in Newgate Prison. This was successful and in 1722 Princess Augusta, the Princess of Wales, the success of these variolations assured the British people that the procedure was safe. Stimulated by an epidemic, variolation was first employed in North America in 1721. The practice was, at first, widely criticized, however, a limited trial showed six deaths occurred out of 244 who were variolated, while 844 out of 5980 died of natural disease, and the process was widely adopted throughout the colonies. The inoculation technique was documented as having a mortality rate of one in a thousand. Two years after Kennedys description appeared, March 1718, Dr, there is a set of old women who make it their business to perform the operation. Every autumn in the month of September, when the heat is abated. They make parties for this purpose, and when they are met the old woman comes with a full of the matter of the best sort of small-pox. The children or young patients play together all the rest of the day and are in perfect health till the eighth, then the fever begins to seize them and they keep their beds two days, very seldom three
Smallpox vaccine
–
Smallpox vaccine being administered. Note the
bifurcated needle.
Smallpox vaccine
–
An 1802 caricature by
James Gillray depicting the early controversy surrounding Jenner's vaccination theory
Smallpox vaccine
–
Smallpox eradication promotional poster
Smallpox vaccine
–
Smallpox vaccination lesion, ten days after vaccination.
26.
Variolation
–
The procedure was most commonly carried out by inserting/rubbing powdered smallpox scabs or fluid from pustules into superficial scratches made in the skin. The patient would develop pustules identical to those caused by naturally occurring smallpox, eventually, after about two to four weeks, these symptoms would subside, indicating successful recovery and immunity. The method was first used in China and the Middle East before it was introduced into England, the method is no longer used today. It was replaced by smallpox vaccine, a safer alternative and this in turn led to the development of the many vaccines now available against other diseases. The terminology used to describe the prevention of smallpox can cause confusion, in 18th-century medical terminology, inoculation refers to smallpox inoculation. Confusion is caused by writers who interchange variolation and vaccination through either mistranslation or misinterpretation, the term variolation refers solely to inoculation with smallpox virus and is not interchangeable with vaccination. The latter term was first used in 1800 soon after Edward Jenner introduced smallpox vaccine derived from cowpox, the term variolation was then used from the 19th century to avoid confusion with vaccination. Most modern writers tend to refer to smallpox inoculation as variolation throughout without regard for chronology, further confusion was caused when, in 1891, Louis Pasteur honoured Jenner by widening the terms vaccine/vaccination to refer to the artificial induction of immunity against any infectious disease. Inoculation is used synonymously with injection in connection with the use of vaccines or other biopharmaceuticals, the Chinese practiced the oldest documented use of variolation, dating back to the fifteenth century. They implemented a method of nasal insufflation administered by blowing powdered smallpox material, usually scabs, various insufflation techniques have been recorded throughout the sixteenth and seventeenth centuries within China. According to such documentation, mild smallpox cases were selected as donors in order to prevent serious attack, the technique used scabs that had been left to dry out for some time. Fresh scabs were more likely to lead to a full-blown infection, three or four scabs were ground into powder or mixed with a grain of musk and bound in cotton. Infected material was packed into a pipe and puffed up the patients nostril. The practice of variolation is believed to have been ritualized by the Chinese, the blowpipe used during the procedure was made of silver. The right nostril was used for boys and the left for girls, variolated cases were treated as if they were as infectious as those who had acquired the disease naturally. These patients were kept apart from others until the rash had cleared. Similar methods were seen through the Middle East and Africa, two similar methods were described in Sudan during the late eighteenth and early nineteenth centuries. Both had been established and stemmed from Arabic practices
Variolation
–
Portrait of Lady Mary Wortley Montagu
27.
Louis Pasteur
–
Louis Pasteur was a French biologist, microbiologist and chemist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization. He is remembered for his breakthroughs in the causes and prevention of diseases. He reduced mortality from puerperal fever, and created the first vaccines for rabies and his medical discoveries provided direct support for the germ theory of disease and its application in clinical medicine. He is best known to the public for his invention of the technique of treating milk and wine to stop bacterial contamination. He is regarded as one of the three founders of bacteriology, together with Ferdinand Cohn and Robert Koch, and is popularly known as the father of microbiology. Pasteur was responsible for disproving the doctrine of spontaneous generation and he performed experiments that showed that without contamination, microorganisms could not develop. Under the auspices of the French Academy of Sciences, he demonstrated that in sterilized and sealed flasks nothing ever developed, although Pasteur was not the first to propose the germ theory, his experiments indicated its correctness and convinced most of Europe that it was true. Today, he is regarded as one of the fathers of germ theory. Pasteur also made significant discoveries in chemistry, most notably on the basis for the asymmetry of certain crystals. Early in his career, his investigation of tartaric acid resulted in the first resolution of what is now called optical isomers and his work led the way to the current understanding of a fundamental principle in the structure of organic compounds. He was the director of the Pasteur Institute, established in 1887, till his death, although Pasteur made groundbreaking experiments, his reputation became associated with various controversies. Historical reassessment of his notebook revealed that he practiced deception to overcome his rivals, Louis Pasteur was born on December 27,1822, in Dole, Jura, France, to a Catholic family of a poor tanner. He was the child of Jean-Joseph Pasteur and Jeanne-Etiennette Roqui. The family moved to Marnoz in 1826 and then to Arbois in 1827, Pasteur entered primary school in 1831. He was a student in his early years, and not particularly academic. He drew many pastels and portraits of his parents, friends, Pasteur attended secondary school at the Collège dArbois. In October 1838, he left for Paris to join the Pension Barbet, in 1839, he entered the Collège Royal de Besançon to study philosophy and earned his Bachelor of Letters degree in 1840. He was appointed a tutor at the Besançon college while continuing a degree course with special mathematics
Louis Pasteur
–
Photograph by
Nadar
Louis Pasteur
–
The house in which Pasteur was born,
Dole
Louis Pasteur
–
Pasteur in 1857
Louis Pasteur
–
Pasteur experimenting in his laboratory.
28.
Active immunity
–
The adaptive immune system is one of the two main immunity strategies found in vertebrates. Adaptive immunity creates immunological memory after a response to a specific pathogen. This process of acquired immunity is the basis of vaccination, like the innate system, the adaptive system includes both humoral immunity components and cell-mediated immunity components. Unlike the innate system, the adaptive immune system is highly specific to a particular pathogen. Adaptive immunity can also provide long-lasting protection, for example, someone who recovers from measles is now protected against measles for their lifetime, in other cases it does not provide lifetime protection, for example, chickenpox. The adaptive system response destroys invading pathogens and any toxic molecules they produce, sometimes the adaptive system is unable to distinguish harmful from harmless foreign molecules, the effects of this may be hayfever, asthma or any other allergy. Antigens are any substances that elicit the immune response. The cells that carry out the immune response are white blood cells known as lymphocytes. Two main broad classes—antibody responses and cell mediated immune response—are also carried by two different lymphocytes, in antibody responses, B cells are activated to secrete antibodies, which are proteins also known as immunoglobulins. Antibodies travel through the bloodstream and bind to the foreign antigen causing it to inactivate, in acquired immunity, pathogen-specific receptors are acquired during the lifetime of the organism. The acquired response is called adaptive because it prepares the immune system for future challenges. The system is highly adaptable because of somatic hypermutation, and VJ recombination and this mechanism allows a small number of genes to generate a vast number of different antigen receptors, which are then uniquely expressed on each individual lymphocyte. A theoretical framework explaining the workings of the immune system is provided by immune network theory. This theory, which builds on established concepts of clonal selection, is being applied in the search for an HIV vaccine, the major functions of the adaptive immune system include, Recognition of specific non-self antigens in the presence of self, during the process of antigen presentation. Generation of responses that are tailored to eliminate specific pathogens or pathogen-infected cells. Development of immunological memory, in which pathogens are remembered through memory B cells, the cells of the adaptive immune system are T and B lymphocytes, lymphocytes are a subset of leukocyte. B cells and T cells are the types of lymphocytes. The human body has about 2 trillion lymphocytes, constituting 20–40% of white blood cells, the peripheral blood contains 2% of circulating lymphocytes, the rest move within the tissues and lymphatic system
Active immunity
–
A
scanning electron microscope (SEM) image of a single human
lymphocyte
29.
Centers for Disease Control and Prevention
–
The Centers for Disease Control and Prevention is the leading national public health institute of the United States. The CDC is a United States federal agency under the Department of Health and Human Services, headquartered near Atlanta and its main goal is to protect public health and safety through the control and prevention of disease, injury, and disability in the US and internationally. The CDC focuses national attention on developing and applying disease control, the Communicable Disease Center was founded July 1,1946, as the successor to the World War II Malaria Control in War Areas program of the Office of National Defense Malaria Control Activities. Preceding its founding, organizations with global influence in malaria control were the Malaria Commission of the League of Nations, the Rockefeller Foundation greatly supported malaria control, sought to have the governments take over some of its efforts, and collaborated with the agency. The new agency was a branch of the U. S, Public Health Service and Atlanta was chosen as the location because malaria was endemic in the Southern United States. The agency changed names before adopting the name Communicable Disease Center in 1946, Offices were located on the sixth floor of the Volunteer Building on Peachtree Street. Among its 369 employees, the jobs at CDC were originally entomology. In CDCs initial years, more than six and a million homes were sprayed. In 1946, there were only seven officers on duty. Under Joseph Walter Mountin, the CDC continued to advocate for health issues. In 1947, the CDC made a payment of $10 to Emory University for 15 acres of land on Clifton Road in DeKalb County. CDC employees collected the money to make the purchase, the benefactor behind the “gift” was Robert W. Woodruff, chairman of the board of The Coca-Cola Company. Woodruff had a long-time interest in control, which had been a problem in areas where he went hunting. The same year, the PHS transferred its San Francisco based plague laboratory into the CDC as the Epidemiology Division, the mission of CDC expanded beyond its original focus on malaria to include sexually transmitted diseases when the Venereal Disease Division of the U. S. Public Health Service was transferred to the CDC in 1957, shortly thereafter, Tuberculosis Control was transferred to the CDC from PHS, and then in 1963 the Immunization program was established. It became the National Communicable Disease Center effective July 1,1967, the organization was renamed the Center for Disease Control on June 24,1970, and Centers for Disease Control effective October 14,1980. An act of the United States Congress appended the words and Prevention to the name effective October 27,1992, however, Congress directed that the initialism CDC be retained because of its name recognition. Currently the CDC focus has broadened to include chronic diseases, disabilities, injury control, workplace hazards, environmental health threats, and terrorism preparedness
Centers for Disease Control and Prevention
–
CDC headquarters in
Druid Hills, Georgia, as seen from
Emory University
Centers for Disease Control and Prevention
–
Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
–
CDC′s Roybal campus in Atlanta, Georgia
Centers for Disease Control and Prevention
–
Arlen Specter Headquarters and Emergency Operations Center
30.
Mumps
–
MUMPS, or alternatively M, is a general-purpose computer programming language that provides ACID transaction processing. The M database is a database engine optimized for high-throughput transaction processing. As such it is in the class of schema-less, schema-free, internally, M stores data in multidimensional hierarchical sparse arrays. Each array may have up to 32 subscripts, or dimensions, a scalar can be thought of as an array element with zero subscripts. Nodes with varying numbers of subscripts can freely co-exist in the same array, perhaps the most unusual aspect of the M language is the notion that the database is accessed through variables, rather than queries or retrievals. This means that accessing volatile memory and non-volatile storage use the basic syntax. Practically, this provides for high performance data access. Originally designed in 1966 for the industry, M continues to be used today by many large hospitals. MUMPS was developed by Neil Pappalardo, Robert Greenes, and Curt Marble in Dr. Octo Barnetts animal lab at the Massachusetts General Hospital in Boston during 1966 and 1967, the original MUMPS system was, like Unix a few years later, built on a spare DEC PDP-7. MUMPS was then a language, yet even then, incorporated a hierarchical database file system to standardize interaction with the data. Some aspects of MUMPS can be traced from Rand Corporations JOSS through BBNs TELCOMP and STRINGCOMP, the MUMPS team deliberately chose to include portability between machines as a design goal. Another feature, not widely supported for machines of the era, in operating systems or in computer hardware, was multitasking, the portability was soon useful, as MUMPS was shortly adapted to a DEC PDP-15, where it lived for some time. Word about MUMPS spread mostly through the community, and by the early 1970s was in widespread use. By the early 1970s, there were many and varied implementations of MUMPS on a range of hardware platforms, the most widespread was DECs MUMPS-11 on the PDP-11, and MEDITECHs MIIS. In 1972, many MUMPS users attended a conference which standardized the then-fractured language and these efforts proved successful, a standard was complete by 1974, and was approved, on September 15,1977, as ANSI standard, X11. 1-1977. At about the same time DEC launched DSM-11 for the PDP-11 and this quickly dominated the market, and became the reference implementation of the time. Also, InterSystems sold ISM-11 for the PDP-11, during the early 1980s several vendors brought MUMPS-based platforms that met the ANSI standard to market. The most significant were, Digital Equipment Corporation with DSM, DSM-11 was superseded by VAX/DSM for the VAX/VMS platform, and that was ported to the Alpha in two variants, DSM for OpenVMS, and as DSM for Ultrix
Mumps
31.
MMR vaccine
–
The MMR vaccine is an immunization vaccine against measles, mumps, and rubella. It is a mixture of live attenuated viruses of the three diseases, administered via injection and it was first developed by Maurice Hilleman while at Merck. A licensed vaccine to prevent measles first became available in 1963, vaccines for mumps and rubella became available in 1967 and 1969, respectively. The three vaccines were combined in 1971 to become the measles-mumps-rubella vaccine, the MMR vaccine is generally administered to children around the age of one year, with a second dose before starting school. The second dose is a dose to produce immunity in the number of persons who fail to develop measles immunity after the first dose. In the United States, the vaccine was licensed in 1971 and it is widely used around the world, since introduction of its earliest versions in the 1970s, over 500 million doses have been used in over 60 countries. The vaccine is sold by Merck as M-M-R II, GlaxoSmithKline Biologicals as Priorix, Serum Institute of India as Tresivac and it is usually considered a childhood vaccination. However, it is recommended for use in some cases of adults with HIV. Before the widespread use of a vaccine against measles, its incidence was so high that infection with measles was felt to be as inevitable as death and taxes. Reported cases of measles in the United States fell from hundreds of thousands to tens of thousands per year following introduction of the vaccine in 1963, increasing uptake of the vaccine following outbreaks in 1971 and 1977 brought this down to thousands of cases per year in the 1980s. An outbreak of almost 30,000 cases in 1990 led to a push for vaccination. Fewer than 200 cases have been reported each year between 1997 and 2013, and the disease is no longer considered endemic, the benefit of measles vaccination in preventing illness, disability, and death has been well documented. The first 20 years of licensed measles vaccination in the U. S. prevented an estimated 52 million cases of the disease,17,400 cases of intellectual disability, and 5,200 deaths. During 1999–2004, a strategy led by the World Health Organization, between 2000 and 2013, measles vaccination resulted in a 75% decrease in deaths from the disease. Of the 66 cases of reported in the U. S. in 2005. This individual returned to a community with many unvaccinated children, the resulting outbreak infected 34 people, mostly children and virtually all unvaccinated, 9% were hospitalized, and the cost of containing the outbreak was estimated at $167,685. A major epidemic was averted due to rates of vaccination in the surrounding communities. Mumps is another disease of childhood that was once very common
MMR vaccine
–
Maurice Hilleman
MMR vaccine
–
Two workers make openings in chicken eggs in preparation for a measles vaccine
32.
Live attenuated influenza vaccine
–
Live attenuated influenza vaccine is a type of influenza vaccine in the form of a nasal spray that used to be recommended to prevent influenza. In June 2016 the CDC stopped recommending the use of LAIV as its effectiveness has appeared to have decreased between 2013 and 2016 and it is an attenuated vaccine, unlike most influenza vaccines, which are inactivated vaccines. LAIV is administered intranasally, while inactivated vaccines are administered by intramuscular injection, both live attenuated and inactivated vaccines are typically trivalent. LAIV is sold under the trade name FluMist in the United States and Canada, FluMist is manufactured by MedImmune and was first introduced in 2003. In 2016 the CDC recommended that LAIV not be used for the 2016-2017 flu season and this is due to the poor effectiveness of this type of vaccine between 2013 and 2016 with it being non effective during the 2015-2016 season. A2012 review found that LAIV prevents influenza in about one out of six children under six it is given to and it was believed to prevent about 50% more cases of flu than the flu shot in younger children. In those less than 2 years old evidence the evidence was however unclear, why there appears to be a decrease in effectiveness is unknown. Children <24 months of age, due to increased risk of wheezing individuals with a history of hypersensitivity to previous influenza vaccination, for this reason it is recommended that those vaccinated with FluMist avoid close contact with individuals with weak immune systems during that time. Even though the virus in LAIV is attenuated, it is still a living virus, in contrast, inactivated virus vaccines contain no living virus, and cannot cause a live infection. Persons receiving LAIV may shed small amounts of the virus during the first week. People coming in contact with the person are not considered to be at risk. MedImmune, Inc. purchased Aviron in 2002, and the FDA approved FluMist in June 2003, FluMist was first made available in September 2003. The U. S. FDA initially approved FluMist only for people ages 5 to 49 because of concerns over possible side effects. Now FluMist is approved and recommended for healthy children 24 months of age, the FDA approved the current unfrozen refrigerated version for the same age group in August 2006 following completion of phase 3 clinical trials. CAIV-T has been approved by the FDA and is the version offered on the beginning in fall of 2007. The current version of the vaccine is called CAIV-T, and is stable for storage in a refrigerator, approved for the 2007-2008 flu season, the refrigerated formulation can be distributed more economically, so that the price differential with shots is now largely eliminated. The price was lowered the next year, and the company reports distributing 1.6 million doses in 2005. Because of the drop, despite selling almost three times as many doses in 2005, the company reported $21 million in FluMist sales
Live attenuated influenza vaccine
–
Influenza (Flu)
Live attenuated influenza vaccine
–
Nurse administering the FluMist product to a patient.
33.
Passive immunity
–
Passive immunity is the transfer of active humoral immunity in the form of ready-made antibodies. Passive immunization can be provided when people cannot synthesize antibodies, maternal passive immunity is a type of naturally acquired passive immunity, and refers to antibody-mediated immunity conveyed to a fetus or infant by its mother. Naturally acquired passive immunity can be provided during pregnancy, and through breast-feeding, in humans, maternal antibodies are passed through the placenta to the fetus by an FcRn receptor on placental cells. This occurs predominately during the third trimester of pregnancy, and thus is reduced in babies born prematurely. Immunoglobulin G is the only isotype that can pass through the human placenta. IgG antibodies protects against bacterial and viral infections in fetuses and this effect is usually overcome by secondary responses to booster immunization. Maternal antibodies protect against some diseases more than such as measles, rubella, and tetanus compared to the protection provided against polio. Maternal passive immunity offers immediate protection, though protection mediated by maternal IgG typically only lasting four to six months after birth, only a few other species besides humans transfer maternal antibodies before birth, including primates and lagomorphs. In some of these species IgM can be transferred across the placenta as well as IgG, all other mammalian species predominantly or solely transfer maternal antibodies after birth through milk. In these species, the gut is able to absorb IgG for hours to days after birth. However, after a period of time the neonate can no longer absorb maternal IgG through their gut, an event that is referred to as gut closure. If a neonatal animal does not receive adequate amounts of colostrum prior to gut closure, is does not have a sufficient amount of maternal IgG in its blood to fight off common diseases and this condition is referred to as failure of passive transfer. It can be diagnosed by measuring the amount of IgG in a newborns blood, if not treated, it can be fatal. Passive transfer is used to prevent disease or used prophylactically in the case of immunodeficiency diseases and it is also used in the treatment of several types of acute infection, and to treat poisoning. Immunity derived from passive immunization lasts for a few weeks to three to four months, there is also a potential risk for hypersensitivity reactions, and serum sickness, especially from gamma globulin of non-human origin. By 1896, the introduction of diphtheria antitoxin was hailed as the most important advance of the Century in the treatment of acute infective disease. Prior to the advent of vaccines and antibiotics, specific antitoxin was often the treatment available for infections such as diphtheria. Immunoglobulin therapy continued to be a first line therapy in the treatment of respiratory diseases until the 1930s
Passive immunity
–
A vial of diphtheria antitoxin, dated 1895
34.
Antibodies
–
An antibody, also known as an immunoglobulin, is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as bacteria and viruses. The antibody recognizes a molecule of the harmful agent, called an antigen. Each tip of the Y of an antibody contains a paratope that is specific for one particular epitope on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or a cell for attack by other parts of the immune system. Depending on the antigen, the binding may impede the process causing the disease or may activate macrophages to destroy the foreign substance. The ability of an antibody to communicate with the components of the immune system is mediated via its Fc region. The production of antibodies is the function of the humoral immune system. Antibodies are secreted by B cells of the immune system. In most cases, interaction of the B cell with a T helper cell is necessary to produce full activation of the B cell and, therefore, soluble antibodies are released into the blood and tissue fluids, as well as many secretions to continue to survey for invading microorganisms. Antibodies are glycoproteins belonging to the immunoglobulin superfamily and they constitute most of the gamma globulin fraction of the blood proteins. They are typically made of basic structural units—each with two heavy chains and two small light chains. There are several different types of heavy chains that define the five different types of crystallisable fragments that may be attached to the antigen-binding fragments. The five different types of Fc regions allow antibodies to be grouped into five isotypes, each Fc region of a particular antibody isotype is able to bind to its specific Fc Receptor, thus allowing the antigen-antibody complex to mediate different roles depending on which FcR it binds. The ability of an antibody to bind to its corresponding FcR is further modulated by the structure of the present at conserved sites within its Fc region. The ability of antibodies to bind to FcRs helps to direct the immune response for each different type of foreign object they encounter. For example, IgE is responsible for an allergic response consisting of mast cell degranulation, igEs Fab paratope binds to allergic antigen, for example house dust mite particles, while its Fc region binds to Fc receptor ε. The allergen-IgE-FcRε interaction mediates allergic signal transduction to induce conditions such as asthma and this region is known as the hypervariable region. Each of these variants can bind to a different antigen and this enormous diversity of antibody paratopes on the antigen-binding fragments allows the immune system to recognize an equally wide variety of antigens
Antibodies
–
Immunofluorescence image of the eukaryotic
cytoskeleton.
Actin filaments are shown in red,
microtubules in green, and the
nuclei in blue.
Antibodies
–
Each antibody binds to a specific
antigen; an interaction similar to a lock and key.
Antibodies
–
Example of tissue cross-reactivity on human
tissue microarray
Antibodies
–
Angel of the West (2008) by
Julian Voss-Andreae is a sculpture based on the antibody structure published by E. Padlan. Created for the Florida campus of
the Scripps Research Institute, the antibody is placed into a ring referencing
Leonardo da Vinci's Vitruvian Man thus highlighting the similarity of the antibody and the human body.
35.
Fetus
–
A fetus is a stage in the prenatal development of viviparous organisms. In human development, a fetus or foetus is a human between the embryonic state and birth. The fetal stage of development tends to be taken as beginning at the age of eleven weeks. In biological terms, however, prenatal development is a continuum, the use of the term fetus generally implies that an embryo has developed to the point of being recognizable as a human, this is the point usually taken to be the ninth week after fertilization. A fetus is also characterized by the presence of all the body organs, though they will not yet be fully developed and functional. The word fetus is from the Latin fētus, the British, Irish, and Commonwealth spelling is foetus, which has been in use since at least 1594. It arose as a hypercorrection based on an incorrect etymology that may have originated with an error by Isidore of Seville in AD620 and this spelling is the most common in most Commonwealth nations, except in the medical literature, where fetus is used. The etymologically accurate original spelling fetus is used in Canada and the United States, in addition, fetus is now the standard English spelling throughout the world in medical journals. The spelling faetus was used historically, in humans, the fetal stage commences at the beginning of the ninth week. At the start of the stage, the fetus is typically about 30 millimetres in length from crown to rump. The head makes up half of the fetus size. Breathing-like movement of the fetus is necessary for stimulation of lung development, the heart, hands, feet, brain and other organs are present, but are only at the beginning of development and have minimal operation. The genitalia of the starts to form and placenta becomes fully functional during week 9. At this point in development, uncontrolled movements and twitches occur as muscles, the brain, and pathways begin to develop. A woman pregnant for the first time, typically feels fetal movements at about 21 weeks, whereas a woman who has given birth at least once, by the end of the fifth month, the fetus is about 20 cm long. The amount of body fat rapidly increases, thalamic brain connections, which mediate sensory input, form. Bones are fully developed, but are soft and pliable. Iron, calcium, and phosphorus become more abundant, fingernails reach the end of the fingertips
Fetus
–
A human fetus, attached to
placenta, at around twelve weeks after
fertilization. Until around nine weeks after fertilization, this prenatal human would have been described as an
embryo.
Fetus
–
3D ultrasound of 3-inch (76 mm) fetus (about 14 weeks
gestational age)
Fetus
–
Fetus at 17 weeks
Fetus
–
Fetus at 20 weeks
36.
Injection (medicine)
–
An injection follows a parenteral route of administration, that is, administration via a route other than through the digestive tract. Since the process involves a small puncture wound to the body. Rodents used for research are often administered intracerebral, intracerebroventricular, or intraportal injections as well, long-acting forms of subcutaneous/intramuscular injections are available for various drugs, and are called depot injections. Injections are among the most common health care procedures, with at least 16 billion administered in developing, 95% of injections are administered in curative care, 3% are for immunization, and the rest for other purposes, such as blood transfusions. In some instances the term injection is used synonymously with inoculation even by different workers in the same hospital and this should not cause confusion, the focus is on what is being injected/inoculated, not the terminology of the procedure. In an intramuscular injection, the medication is delivered directly into a muscle, many vaccines are administered intramuscularly, as are codeine, metoclopramide, and many other medications. Many drugs injected intramuscularly are absorbed into the muscle fairly quickly, injections to the buttocks are known to reach the bloodstream quickly due to the large amount of muscular tissue and corresponding blood supply. Such injection allows the compound to be released in a consistent way over a long period. Depot injections are usually either solid or oil-based, depot injections may be available as certain forms of a drug, such as decanoate salts or esters. Examples of depot injections include Depo Provera and haloperidol decanoate, prostate cancer patients receiving hormone therapy usually get depot injections as a treatment or therapy. Zoladex is an example of a medication delivered by depot for prostate cancer treatment or therapy, naltrexone may be administered in a monthly depot injection to control opiod abuse, in this case, the depot injection improves compliance by replacing daily pill administration. The advantages of using a long-acting depot injection include increased medication compliance due to reduction in the frequency of dosing, a significant disadvantage is that the drug is not immediately reversible, since it is slowly released. In psychiatric nursing, a short acting depot, zuclopenthixol acetate, the pharmaceutical injection type of infiltration involves loading a volume of tissue with the drug, filling the interstitial space. Local anesthetics are often infiltrated into the dermis and hypodermis, various animals, and some plants, have been injecting for various reasons long before humans began doing so in a process commonly called stinging. Some examples include, Snakes, wasps, scorpions, venom, to kill prey, some bees, venom, to defend themselves and their nests. Stinging nettles, venom, to try to avoid being eaten, stingrays, venom, defense mechanism when provoked. The pain of an injection may be lessened by prior application of ice or topical anesthetic, recent studies suggest that forced coughing during an injection stimulates a transient rise in blood pressure which inhibits the perception of pain. Sometimes, as with an amniocentesis, an anesthetic is given
Injection (medicine)
–
A
Somali boy receiving a
subcutaneous injection of
polio vaccine
Injection (medicine)
–
An
intramuscular injection
37.
Humanized antibodies
–
Humanized antibodies are antibodies from non-human species whose protein sequences have been modified to increase their similarity to antibody variants produced naturally in humans. The process of humanization is usually applied to monoclonal antibodies developed for administration to humans, humanization can be necessary when the process of developing a specific antibody involves generation in a non-human immune system. There are other types of antibodies developed, the International Nonproprietary Names of humanized antibodies end in -zumab, as in omalizumab. Humanized antibodies are distinct from chimeric antibodies, the latter also have their protein sequences made more similar to human antibodies, but carry a larger stretch of non-human protein. The step involving recombinant DNA provides a point that can be readily exploited to alter the protein sequence of the expressed antibody. The alterations to antibody structure that are achieved in the process are therefore all effectuated through techniques at the DNA level. Humanization is usually seen as distinct from the creation of an antibody chimera. So, although the creation of a chimera is normally undertaken to achieve a more human-like antibody simple chimeras of this type are not usually referred to as humanized. Chimeric antibody names contain a -xi- stem, examples of chimeric antibodies approved for human therapy include abciximab, basiliximab, cetuximab, infliximab and rituximab. There are also examples of chimerics currently in clinical trials. The humanization process may, however, include the creation of a chimera in an initial step. Thereafter the chimera might be further humanized by the alteration of the sequence of amino acids in the Fab portion of the molecule. The process must be selective to retain the specificity for which the antibody was originally developed, aside from the CDR segments, the portions of the Fab sequence that differ from those in humans can be corrected by exchanging the appropriate individual amino acids. This is accomplished at the DNA level using mutagenesis, naming of humanized chimeras includes the stem for both designations. Otelixizumab is an example of a humanized chimera currently in trials for treatment of rheumatoid arthritis. It is possible to produce a humanized antibody without creating a chimeric intermediate, direct creation of a humanized antibody can be accomplished by inserting the appropriate CDR coding segments into a human antibody scaffold. As discussed above, this is achieved through recombinant DNA methods using an appropriate vector and that is, after an antibody is developed to have the desired properties in a mouse, the DNA coding for that antibody can be isolated, cloned into a vector and sequenced. The DNA sequence corresponding to the antibody CDRs can then be determined, once the precise sequence of the desired CDRs are known, a strategy can be devised for inserting these sequences appropriately into a construct containing the DNA for a human antibody variant
Humanized antibodies
–
Sketches of
chimeric (top right), humanized (bottom left) and chimeric/humanized (bottom middle) monoclonal antibodies. Human parts are shown in brown, non-human parts in blue.
38.
In vitro
–
In vitro studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. In contrast, in studies are those conducted in animals, including humans. In vitro studies are conducted using components of an organism that have been isolated from their biological surroundings, such as microorganisms, cells. For example, microrganisms or cells can be studied in artificial culture media, colloquially called test-tube experiments, these studies in biology, medicine, and their subdisciplines are traditionally done in test tubes, flasks, Petri dishes, etc. They now involve the range of techniques used in molecular biology. In contrast, studies conducted in living beings are called in vivo, polymerase chain reaction is a method for selective replication of specific DNA and RNA sequences in the test tube. Protein purification involves the isolation of a protein of interest from a complex mixture of proteins. In vitro fertilization is used to allow spermatozoa to fertilize eggs in a culture dish before implanting the resulting embryo or embryos into the uterus of the prospective mother and these ADME process parameters can then be integrated into so called physiologically based pharmacokinetic models or PBPK. In vitro studies permit a species-specific, simpler, more convenient, just as studies in whole animals more and more replace human trials, so are in vitro studies replacing studies in whole animals. This complexity makes it difficult to identify the interactions between individual components and to explore their basic biological functions, in vitro work simplifies the system under study, so the investigator can focus on a small number of components. Another advantage of in vitro methods is that cells can be studied without extrapolation from an experimental animals cellular response. Investigators doing in vitro work must be careful to avoid over-interpretation of their results, for example, scientists developing a new viral drug to treat an infection with a pathogenic virus may find that a candidate drug functions to prevent viral replication in an in vitro setting. However, before this drug is used in the clinic, it must progress through a series of in vivo trials to determine if it is safe and effective in intact organisms. Results obtained from in vitro experiments cannot usually be transposed, as is, building a consistent and reliable extrapolation procedure from in vitro results to in vivo is therefore extremely important. However, increasingly sophisticated in vitro experiments collect increasingly numerous, complex, mathematical models, such as systems biology models, are much needed here. In pharmacology, IVIVE can be used to approximate pharmacokinetics or pharmacodynamics and that indicates that extrapolating effects observed in vitro needs a quantitative model of in vivo PK. Physiologically based PK models are generally accepted to be central to the extrapolations, in these conditions, developing a simple PD model of the dose–response relationship observed in vitro, and transposing it without changes to predict in vivo effects is not enough
In vitro
–
Top view of a module base (lid removed) looking into the four separated wells where cell culture inserts would usually sit and be exposed to tobacco smoke or an
aerosol for an in-vitro study of the effects.
39.
Cell culture
–
Cell culture is the process by which cells are grown under controlled conditions, generally outside of their natural environment. Most cells require a surface or an artificial substrate whereas others can be free floating in culture medium. The historical development and methods of culture are closely interrelated to those of tissue culture. Viral culture is related, with cells as hosts for the viruses. The laboratory technique of maintaining live cell lines separated from their original tissue source became more robust in the middle 20th century. In 1885, Wilhelm Roux removed a portion of the plate of an embryonic chicken and maintained it in a warm saline solution for several days. Ross Granville Harrison, working at Johns Hopkins Medical School and then at Yale University, published results of his experiments from 1907 to 1910, Cell culture techniques were advanced significantly in the 1940s and 1950s to support research in virology. Growing viruses in cell cultures allowed preparation of purified viruses for the manufacture of vaccines, the injectable polio vaccine developed by Jonas Salk was one of the first products mass-produced using cell culture techniques. Cells can be isolated from tissues for ex vivo culture in several ways, cells can be easily purified from blood, however, only the white cells are capable of growth in culture. Mononuclear cells can be released from soft tissues by enzymatic digestion with enzymes such as collagenase, trypsin, or pronase, alternatively, pieces of tissue can be placed in growth media, and the cells that grow out are available for culture. This method is known as explant culture, cells that are cultured directly from a subject are known as primary cells. With the exception of some derived from tumors, most primary cell cultures have limited lifespan, numerous cell lines are well established as representative of particular cell types. For the majority of isolated cells, they undergo the process of senescence. Cells are grown and maintained at a temperature and gas mixture in a cell incubator. Culture conditions vary widely for each type, and variation of conditions for a particular cell type can result in different phenotypes. Aside from temperature and gas mixture, the most commonly varied factor in culture systems is the growth medium. Recipes for growth media can vary in pH, glucose concentration, growth factors, the growth factors used to supplement media are often derived from the serum of animal blood, such as fetal bovine serum, bovine calf serum, equine serum, and porcine serum. One complication of these blood-derived ingredients is the potential for contamination of the culture with viruses or prions, current practice is to minimize or eliminate the use of these ingredients wherever possible and use human platelet lysate
Cell culture
–
Cell culture in a special tissue culture dish
Cell culture
–
Epithelial cells in culture,
stained for
keratin (red) and
DNA (green)
Cell culture
–
A bottle of DMEM cell culture medium
Cell culture
–
Cultured
HeLa cells have been stained with
Hoechst turning their
nuclei blue, and are one of the earliest human cell lines descended from
Henrietta Lacks, who died of cervical cancer from which these cells originated.
40.
Influenza vaccine
–
Influenza vaccines, also known as flu shots or jabs, are vaccines that protect against influenza. A new version of the vaccine is developed twice a year as the influenza virus rapidly changes, while their effectiveness varies from year to year, most provide modest to high protection against influenza. They decrease the number of missed days of work by a day on average. Vaccinating children may protect those around them, the effectiveness in those under two years old and over 65 years old is unknown due to the low quality of the research. The World Health Organization and Centers for Disease Control and Prevention recommends yearly vaccination for all people over the age of six months. The European Centre for Disease Prevention and Control also recommends yearly vaccination of high risk groups and these groups include pregnant women, the elderly, children between six months and five years of age, those with other health problems, and those who work in healthcare. In children, fever occurs in five to ten per cent, in certain years, the vaccine causes Guillain–Barré syndrome in older people in about one per million doses. It should not be given to those with allergies to eggs or to previous versions of the vaccine. The vaccines come in both inactive and weakened viral forms, the inactive version should be used for those who are pregnant. They come in forms that are injected into a muscle, sprayed into the nose, vaccination against influenza began in the 1930s with large scale availability in the United States beginning in 1945. It is on the World Health Organizations List of Essential Medicines, the wholesale price in the developing world is about $5.25 USD per dose as of 2014. In the United States, it costs less than $25 USD, the Centers for Disease Control and Prevention, recommend the flu vaccine as the best way to protect people against the flu and prevent its spread. The flu vaccine can also reduce the severity of the flu if a person contracts a flu strain that the vaccine did not contain and it takes about two weeks following vaccination for protective antibodies to form. In the case of influenza, effectiveness is expected to be lower than the efficacy because it is measured using the rates of influenza-like illness, Influenza vaccines generally show high efficacy, as measured by the antibody production in animal models or vaccinated people. However, in most years, the flu vaccine strains have been a match for the circulating strains. Trials of both live and inactivated vaccines against seasonal influenza have been summarized in several 2012 meta-analyses. Studies on live vaccines have very limited data, but these preparations may be effective than inactivated vaccines. The meta-analyses examined the efficacy and effectiveness of inactivated vaccines against seasonal influenza in adults, children, the CDC recommend that everyone except infants under the age of six months should receive the seasonal influenza vaccine
Influenza vaccine
–
Influenza (Flu)
Influenza vaccine
–
U.S. Navy personnel receiving influenza vaccination
Influenza vaccine
–
A young woman shows off her flu shot after receiving vaccine at a local
drug store.
41.
Vaccine-preventable diseases
–
A vaccine-preventable disease is an infectious disease for which an effective preventive exists. If a person acquires a vaccine-preventable disease and dies from it, the WHO reports licensed vaccines being available to prevent, or contribute to the prevention and control of,25 vaccine-preventable infections. In 2012, the World Health Organization estimated that vaccination prevents 2.5 million deaths each year, four diseases were responsible for 98% of vaccine-preventable deaths, measles, Haemophilus influenzae serotype b, pertussis, and neonatal tetanus. Vaccine-preventable deaths are caused by a failure to obtain the vaccine in a timely manner. This may be due to financial constraints or to lack of access to the vaccine, a vaccine that is generally recommended may be medically inappropriate for a small number of people due to severe allergies or a damaged immune system. In addition, a vaccine against a disease may not be recommended for general use in a given country, or may be recommended only to certain populations. Every country makes its own immunization recommendations, based on the diseases that are common in its area, if a vaccine-preventable disease is uncommon in a country, then residents of that country are unlikely to receive a vaccine against it. Anthrax Plague Q fever Smallpox Vaccination policy World Immunization Week
Vaccine-preventable diseases
–
A child being immunized against
polio.
42.
World Immunization Week
–
World Immunization Week is a global public health campaign to raise awareness and increase rates of immunization against vaccine-preventable diseases around the world. It takes place each year during last week of April, Immunization can protect against 25 different infectious agents or diseases, from infancy to old age, including diphtheria, measles, pertussis, polio and tetanus. The World Health Organization estimates active immunization currently averts 2 to 3 million deaths every year, however 22.6 million infants worldwide are still missing out on basic vaccines, mostly in developing countries. Inadequate immunization coverage rates often result from limited resources, competing health priorities, poor management of health systems, World Immunization Week sprung out of the efforts taking place across different countries and regions for a week-long immunization awareness commemoration. The World Health Assembly endorsed World Immunization Week during its May 2012 meeting, previously, Immunization Week activities were observed on different dates in different regions of the world. Immunization Week was observed simultaneously for the first time in 2012, each World Immunization Week focuses on a theme. The themes have included the following, 2015-2016, Close the immunization gap 2014, Are you up-to-date
World Immunization Week
–
World Immunization Week
World Immunization Week
–
A child being immunized against
polio.
43.
Targeted immunization strategies
–
Targeted immunization strategies are approaches designed to increase the immunization level of populations and decrease the chances of epidemic outbreaks. Identification of at-risk groups and individuals with higher odds of spreading the disease often plays an important role in these strategies, often however these vaccine programmes require the immunization of a large majority of the population to provide herd immunity. More recently researchers have looked at exploiting network connectivity properties to better understand, in large networks this results in the vast majority of nodes having few connections or low degree k, while a few hubs have many more connections than the average <k>. This wide variability in degree offers immunization strategies based on targeting members of the according to their connectivity rather than random immunization of the network. In epidemic modeling on scale-free networks, targeted immunization schemes can lower the vulnerability of a network to epidemic outbreaks over random immunization schemes. Typically these strategies result in the need for far fewer nodes to be immunized in order to provide the level of protection to the entire network as in random immunization. In circumstances then where vaccines are scarce, efficient immunization strategies become necessary to preventing infectious outbreaks, examples A common approach for targeted immunization studies in scale-free networks focuses on targeting the highest degree nodes for immunization. These nodes are the most highly connected in the network, making more likely to spread the contagion if infected. Immunizing this segment of the network can reduce the impact of the disease on the network. However, this relies on knowing the global structure of the network. Another strategy, acquaintance immunization, tries to target all of the most highly connected nodes for immunization by going through their neighbors without knowing the full network topology. In this approach a group of nodes are chosen and then a random set of their neighbors are selected for immunization. These degree based strategies consistently require fewer nodes to be immunized and as such improve a networks chances against epidemic attacks
Targeted immunization strategies
44.
Infant
–
An infant is the more formal or specialised synonym for baby, the very young offspring of a human or other animal. A newborn is, in use, an infant who is only hours, days. In medical contexts, newborn or neonate refers to an infant in the first 28 days after birth, the term applies to premature, full term, and postmature infants, before birth, the term fetus is used. The term infant is typically applied to children under one year of age, however, definitions may vary. When a human child learns to walk, the toddler may be used instead. In British English, infant is a term that can be applied to children aged between four and seven. As a legal term, infancy continues from birth until age 18, a newborns shoulders and hips are wide, the abdomen protrudes slightly, and the arms and legs are relatively long with respect to the rest of their body. In first world nations, the total body length of newborns are 35. 6–50.8 cm. The Apgar score is a measure of a transition from the uterus during the first minutes after birth. In developed countries, the birth weight of a full-term newborn is approximately 3.4 kg. After the first week, healthy term neonates should gain 10–20 grams/day, a newborns head is very large in proportion to the body, and the cranium is enormous relative to his or her face. While the adult human skull is one seventh of the total body length. Normal head circumference for an infant is 33–36 cm at birth. At birth, many regions of the skull have not yet been converted to bone. The two largest are the anterior fontanel, located at the top front portion of the head, and the smaller triangular-shaped posterior fontanel. Later in the life, these bones will fuse together in a natural process. A protein called noggin is responsible for the delay in an infants skull fusion, during labour and birth, the infants skull changes shape to fit through the birth canal, sometimes causing the child to be born with a misshapen or elongated head. It will usually return to normal on its own within a few days or weeks, special exercises sometimes advised by physicians may assist the process
Infant
–
Eight-month-old twin sisters
Infant
–
Eight months old infant; as a common feature eyes are usually larger compared to the face.
Infant
–
A crying newborn, a few days after birth
Infant
–
A newborn baby in Indonesia, with umbilical cord ready to be clamped
45.
Baby food
–
Baby food is any soft, easily consumed food, other than breastmilk or infant formula, that is made specifically for babies, roughly between the ages of four to six months and two years. Baby food can be given when the child is ready to eat. Signs of readiness include the ability to sit without help, loss of tongue thrust, most six-month-old infants are physiologically and developmentally ready for new foods, textures and modes of feeding. Experts advising the World Health Assembly have provided evidence that introducing solids earlier than six months increases babies chances of illness, one of the health concerns associated with the introduction of solid foods before six months is iron deficiency. The early introduction of foods may satisfy the hunger of the infant, resulting in less frequent breastfeeding. This way, if the child is unable to tolerate a certain food, newborns need a diet of breastmilk or infant formula. About 40% of the energy in these milks comes from carbohydrates. Toddlers and preschoolers generally ate too little dietary fiber, and preschoolers generally ate too much saturated fat, micronutrient levels were typically within the recommended levels. A small group of infants in the American study needed more iron and zinc. A substantial proportion of toddlers and preschoolers exceeded the recommended level of synthetic folate, preformed vitamin A, zinc. Baby foods are either a soft, liquid paste or an easily chewed food since babies lack developed muscles, Babies typically move to consuming baby food once nursing or formula is not sufficient for the childs appetite. Babies do not need to have teeth to transition to eating solid foods, teeth, however, normally do begin to show up at this age. Care should be taken with foods that pose a choking hazard, such as undercooked vegetables, grapes. Babies begin eating liquid style baby food consisting of pureed vegetables and fruits, sometimes mixed with rice cereal and formula, then, as the baby is better able to chew, small, soft pieces or lumps may be included. Around 6 months of age, babies may begin to feed themselves with help from parents, homemade baby food is less expensive than commercial baby foods. Homemade food is only when the family has a sufficient and varied diet, as well as access to refrigeration. Homemade food requires more time than opening a jar or box of ready-to-eat commercial baby food. Food may need to be minced or pureed for young babies, or cooked separately without the salt, intense spices, or sugar that the family chooses to eat
Baby food
–
Baby wearing a
bib and eating pureed
green beans.
Baby food
–
Commercial baby food is often a humanitarian relief item, although delivery of
infant formula is criticized because it can discourage breastfeeding and because the local water supplies may be contaminated after a disaster, making powdered infant formula unsafe.
Baby food
–
Market aisle stocked with commercial baby food
Baby food
–
A Hindu child receives its first solid food in a religious ceremony called
Annaprashana
46.
Birth weight
–
Birth weight is the body weight of a baby at its birth. The average birth weight in babies of European heritage is 3.5 kilograms, babies of south Asian and Chinese heritage weigh about 240 grams less. Low birth weight is associated with neonatal infection, the incidence of birth weight being outside what is normal is influenced by the parents in numerous ways, including, Genetics The health of the mother, particularly during the pregnancy. Intercurrent diseases in pregnancy are sometimes associated with decreased birth weight, for example, Celiac disease confers an odds ratio of low birth weight of approximately 1.8. Other factors, like multiple births, where each baby is likely to be outside the AGA, a low birth weight can be caused either by a preterm birth or of the infant being small for gestational age, or a combination of both. This includes theorised links with obesity, diabetes and intelligence, a baby born small or large for gestational age is thought to have an increased risk of obesity in later life, but it was also shown that this relationship is fully explained by maternal weight. GH therapy at a certain dose induced catch-up of lean body mass, however percentage body fat decreased in the GH-treated subjects. Babies that have a low weight are thought to have an increased risk of developing type 2 diabetes in later life. Some studies have shown a link between an increased birth weight and an increased intelligence quotient. Increased birth weight is also linked to greater risk of developing autism, recent evidence suggests that the effects of low birth weight are constant across developmental years, suggesting that poor neonatal care has long term impacts. Barkers hypothesis MOMO syndrome Low birth weight paradox Prenatal nutrition and birth weight MedlinePlus Encyclopedia Intrauterine growth restriction Peleg D, Kennedy CM, Intrauterine growth restriction, identification and management
Birth weight
–
Baby weighed as appropriate for gestational age.
Birth weight
–
Relation of weight and
gestational age.
47.
Breast pump
–
A breast pump is a mechanical device that extracts milk from the breasts of a lactating woman. Breast pumps may be manual devices powered by hand or foot movements or electrical devices powered by batteries or electricity from the grid, on June 20,1854, the United States Patent Office issued Patent No.11,135 to O. H. Colbin as the inventor and patent applicant of a breast pump, Patent 1,644,257 for Laskers breast pump. In 1956 Einar Egnell published his work, Viewpoints on what happens mechanically in the female breast during various methods of milk collection. This article provided insight to the aspects of milk extraction from the breast. The Egnell SMB breastpump designed through this research is quite robust, archaeologists working at a glass factory site in Philadelphia, Pennsylvania, excavated a 19th-century breast pipe that matches breast pumping instruments in period advertisements. Mechanically, a breast pump is analogous to a machine used in commercial dairy production. A misconception is that the breast pump suctions milk out of the breast, a breast pumps job is to trigger the milk ejection response or letdown. Pumps achieve this by using suction to pull the nipple into the tunnel of the breast shield or flange, then release, thirty to sixty cycles per minute can be expected with better-quality electric breast pumps. The breast pump is not as efficient at removing milk from the breast as most nursing babies, most manufacturers have multiple sizes of nipple tunnels available. These tunnels range in size from 24mm to 36mm, there are several types of pump mechanisms. Piston pumps draw a piston through a cylinder to create suction and these are generally considered top-of-the-line units. They have characteristics of low speed, high reliability, low noise, rotary vane pumps use a cam with retractable vanes to create suction. These rotary vane pumps are not widely used anymore, fast diaphragm pumps use a diaphragm that is acted on by a lever, with thousands of cycles per minute. They operate at speed and are usually noisier. Slow diaphragm pumps use a large diaphragm operated by a cam or lever to generate suction with each stroke, pumps have also been designed that use venturi effects powered by a faucet or water stream, wall suction in hospitals, or pumps powered by oral suctioning. A report in 2009 on research done at Stanford University showed the correlation of various factors with mature milk production in mothers of preterm babies. The research found that using massage techniques in addition to a breast pump, a second article on the same study found that the combination of the HOP techniques increased the fat content of the milk expressed
Breast pump
–
Hygeia Enjoye electric breast pump
Breast pump
–
AVENT isis manual breast pump
Breast pump
–
Medela Symphony electric breast pump
Breast pump
–
Medela Lactina Select electric breast pump
48.
Breastfeeding
–
Breastfeeding, also known as nursing, is the feeding of babies and young children with milk from a womans breast. Health professionals recommend that breastfeeding begin within the first hour of a life and continue as often. During the first few weeks of life babies may nurse roughly every two to three hours, the duration of a feeding is usually ten to fifteen minutes on each breast. Mothers may pump milk so that it can be used later when breastfeeding is not possible, Breastfeeding has a number of benefits to both mother and baby, which infant formula lacks. Deaths of an estimated 820,000 children under the age of five could be prevented every year with increased breastfeeding. Breastfeeding decreases the risk of respiratory infections and diarrhea, both in developing and developed countries. Other benefits include lower risks of asthma, food allergies, celiac disease, type 1 diabetes, Breastfeeding may also improve cognitive development and decrease the risk of obesity in adulthood. Mothers may feel pressure to breastfeed, however in the developed world children generally grow up normally when bottle fed, benefits for the mother include less blood loss following delivery, better uterus shrinkage, weight loss, and less postpartum depression. Breastfeeding delays the return of menstruation and fertility, a known as lactational amenorrhea. Long term benefits for the mother include decreased risk of breast cancer, cardiovascular disease, Breastfeeding is less expensive than infant formula. Health organizations, including the World Health Organization, recommend breastfeeding exclusively for six months and this means that no other foods or drinks other than possibly vitamin D are typically given. After the introduction of foods at six months of age, recommendations include continued breastfeeding until at least one to two years of age, globally about 38% of infants are only breastfed during their first six months of life. In the United States, about 75% of women begin breastfeeding, Medical conditions that do not allow breastfeeding are rare. Mothers who take certain drugs and medications should not breastfeed. Smoking, limited intake of alcohol, and coffee are not reasons to avoid breastfeeding, the endocrine system drives milk production during pregnancy and the first few days after the birth. From the twenty-fourth week of pregnancy, a body produces hormones that stimulate the growth of the breasts milk duct system. After birth, the hormone oxytocin contracts the muscle layer of cells surrounding the alveoli to squeeze milk into the duct system. Oxytocin is also necessary for the milk ejection reflex, or let-down to occur, let-down occurs in response to the babys suckling, though it also may be a conditioned response, e. g. to the cry of the baby
Breastfeeding
–
A baby breastfeeding
Breastfeeding
–
Himba woman and child
Breastfeeding
–
Newborn rests as caregiver checks breath sounds
Breastfeeding
–
Rooming-in bassinet
49.
Bottle feeding
–
A baby bottle is a bottle with a teat to drink directly from. It is typically used by infants and young children, or if someone cannot drink from a cup, in particular it is used to feed infant formula, expressed breast milk or pediatric electrolyte solution. A large-sized bottle typically holds 280 ml, the small size 150 ml and it is composed of a bottle itself, a teat, a ring to seal the teat to the bottle, a cap to cover the teat and optionally a disposable liner. The height-to-width ratio of bottles is high because it is needed to ensure the contents flood the teat when used at normal angles, however, if the bottle is too tall, it easily tips. There are asymmetric bottles that ensure the contents flood the teat if the bottle is held at a certain direction, the teat itself is generally designed to be slimmer than the mothers nipple. Teats come in a selection of flow rates, marketed to be based on the age of the infant, different flow rate teats either have more holes or larger holes. Variable flow rate teats are available for older infants, the hole is asymmetric so that by turning the bottle/teat, different flows can occur. Specialized teats are available for infants with cleft palate, vented bottles allow air to enter the bottle while the baby is drinking without the need to break the babys suction during feeding. Alternatively a bottle liner can be used to enclose the formula instead of directly in the bottle, the liner collapses as the formula is drained. Vented bottles work by allowing air to enter while preventing the liquid inside from escaping and it works by an anti-vacuum skirt in the base of the teat, where it forms a seal with the bottle. The skirt acts as a one way valve, allowing air to enter the bottle, if the sealing ring is tightened too much, the skirt is compressed too tightly to allow it to open and the bottle will not vent. If the sealing ring is too loose, liquid leaks from the bottle, there are multiple patents for technologies in this area. Initial designs called for a spring and valve system that was impossible to clean. Current research is in specialized materials with pores that allow the entry of air without the escape of liquids. This avoids the caregiver having to get the sealing ring tension just right and it remains to be seen whether these materials can withstand the rigours of daily cleaning and sterilization. Another competitor, Dr. Browns, offers a system whereby the air is conducted through a tube to the bottom of the bottle where the airspace is when the bottle is in use. This avoids the air from bubbling through the liquid and unnecessarily aerating the liquid. The aeration may cause nutrients in milk and infant formula decrease in concentration
Bottle feeding
–
A
girl being fed by bottle
Bottle feeding
–
A baby bottle of yesteryear (c. 1950s). The double ended bottles didn't actually have two teats; they had a teat and a valve. Photo credit:
Time Tunnel museum.
Bottle feeding
–
An
infant being fed by bottle
Bottle feeding
–
A large-sized feeding bottle designed to transfer breast milk.
50.
Childhood immunizations in the United States
–
The schedule of childhood immunizations in the United States is given by the Centers for Disease Control and Prevention. The vaccination schedule is broken down by age, birth to six years of age, seven to eighteen, childhood Immunizations are key in preventing children for diseases that were once epidemics. It is important to remember that vaccines are continually monitored for safety, there is a risk that the child could have a severe allergic reaction, but these reactions are rare. However, a not to immunize a child also involves risk and could put the child. Hepatitis means inflammation of the liver, Hepatitis B is a contagious virus that effects the liver, infection can last from a few weeks to a serious lifelong illness. Two different types of infection exist for this disease, acute, acute Hepatitis B is a short term illness that occurs within 6 months of exposure, Chronic Hepatitis B is long term and happens when the virus remains in the body. The younger the child is, the greater their chance of developing a chronic infection, approximately 90% of infected infants will develop a chronic infection. Since 1990, when the vaccine was introduced as a routine vaccination in children, rates of acute Hepatitus B has decreased in the United States by 82%. This vaccine is given as a series of shots, the first dose is given at birth, some side effects of this vaccination include, soreness at injection site fever of 99. Hepatitis B is spread in different ways. There is currently no medication to treat acute Hepatitus B and those with chronic Hepatitus B need to be monitored regularly for signs of liver disease, there are currently a few medications to treat chronic Hepatitus B and new drugs are being researched. The rotavirus is most commonly found in infants and young children, prior to the introduction of the vaccine in 2006, almost all children in the United States became infected with the virus before their 5th birthday. Globally, rotavirus is still the cause of half a million deaths each year in children younger than 5 years of age. Unfortunately, there are strains of rotavirus and the vaccine can not cover all of them. Having the illness previously also does not grant immunity, again there are so many different strains. However, the first infection usually causes the most severe symptoms and this vaccine is a little different in that it is a liquid that is given orally, rather than as an injection. This vaccine is a 2 or 3 dose series, depending on the brand of the vaccine, studies show that this vaccine is 85-98% effective against severe rotavirus disease and is 74-87% effective against rotavirus disease of any severity in the first year after the vaccination. If this were to happen, it would occur within a week after the first dose or second dose of the vaccine is given
Childhood immunizations in the United States
–
timeline of the CDC recommended childhood immunization schedule from birth to 6 years of age.
Childhood immunizations in the United States
–
Hepatitis B virus 01
Childhood immunizations in the United States
–
Multiple rotavirus particles
Childhood immunizations in the United States
–
Dirty white pseudomembrane classically seen in diphtheria
