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, by the presence of a T-cell receptor on the cell surface, they are called T cells. The several subsets of T cells each have a distinct function; the majority of human T cells, termed alpha beta T cells, rearrange their alpha and beta chains on the cell receptor and are part of the adaptive immune system. Specialized gamma delta T cells, have invariant T-cell receptors with limited diversity, that can present antigens to other T cells and are considered to be part of the innate immune system. Effector cells are the superset of all the various T cell types that respond to a stimulus, such as co-stimulation; this includes helper, killer and other T cell types. Memory cells are their opposite counterpart that are longer lived to target future infections as necessary. T helper cells assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, 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, which are expressed on the surface of antigen-presenting cells. Once activated, they divide and secrete small proteins called cytokines that regulate or assist in the active immune response; these cells can differentiate into one of several subtypes, including TH1, TH2, TH3, TH17, TH9, or TFH, which secrete different cytokines to facilitate different types of immune responses. Signalling from the APC directs T cells into particular subtypes. Cytotoxic T cells destroy virus-infected cells and tumor cells, are 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, which are present on the surface of all nucleated cells. Through IL-10, other molecules secreted by regulatory T cells, the CD8+ cells can be inactivated to an anergic state, which prevents autoimmune diseases.
Antigen-naïve T cells expand and differentiate into memory and effector T cells after they encounter their cognate antigen within the context of an MHC molecule on the surface of a professional antigen presenting cell. Appropriate co-stimulation must be present at the time of antigen encounter for this process to occur. Memory T cells were thought to belong to either the effector or central memory subtypes, each with their own distinguishing set of cell surface markers. Subsequently, numerous new populations of memory T cells were discovered including tissue-resident memory T cells, stem memory TSCM cells, virtual memory T cells; the single unifying theme for all memory T cell subtypes is that they are long-lived and can expand to large numbers of effector T cells upon re-exposure to their cognate antigen. By this mechanism they provide the immune system with "memory" against encountered pathogens. Memory T cells may be either CD4+ or CD8+ and express CD45RO. Memory T cell subtypes: Central memory T cells express CD45RO, C-C chemokine receptor type 7, L-selectin.
Central memory T cells have intermediate to high expression of CD44. This memory subpopulation is found in the lymph nodes and in the peripheral circulation.. Effector memory T cells lack expression of CCR7 and L-selectin, they have intermediate to high expression of CD44. These memory T cells lack lymph node-homing receptors and are thus found in the peripheral circulation and tissues. TEMRA stands for terminally differentiated effector memory cells re-expressing CD45RA, a marker found on naive T cells. Tissue resident memory T cells occupy tissues without recirculating. One cell surface marker, associated with TRM is the integrin αeβ7. Virtual memory T cells differ from the other memory subsets in that they do not originate following a strong clonal expansion event. Thus, although this population as a whole is abundant within the peripheral circulation, individual virtual memory T cell clones reside at low frequencies. One theory is. Although CD8 virtual memory T cells were the first to be described, it is now known that CD4 virtual memory cells exist.
Regulatory T cells are crucial for the maintenance of immunological tolerance. Their major role is to shut down T cell-mediated immunity toward the end of an immune reaction and to suppress autoreactive T cells that escaped the process of negative selection in the thymus. Suppressor T cells along with Helper T cells can collectively be called Regulatory T cells due to their regulatory functions. Two major classes of CD4 + Treg cells have been described -- FOXP3 − Treg cells. Regulatory T cells can develop either during normal development in the thymus, are known as thymic Treg cells, or can be induced peripherally and are called peripherally derived Treg cel
Heredity is the passing on of traits from parents to their offspring, either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection; the study of heredity in biology is genetics. In humans, eye color is an example of an inherited characteristic: an individual might inherit the "brown-eye trait" from one of the parents. Inherited traits are controlled by genes and the complete set of genes within an organism's genome is called its genotype; the complete set of observable traits of the structure and behavior of an organism is called its phenotype. These traits arise from the interaction of its genotype with the environment; as a result, many aspects of an organism's phenotype are not inherited. For example, suntanned skin comes from the interaction between a person's sunlight. However, some people tan more than others, due to differences in their genotype: a striking example is people with the inherited trait of albinism, who do not tan at all and are sensitive to sunburn.
Heritable traits are known to be passed from one generation to the next via DNA, a molecule that encodes genetic information. DNA is a long polymer; the sequence of bases along a particular DNA molecule specifies the genetic information: this is comparable to a sequence of letters spelling out a passage of text. Before a cell divides through mitosis, the DNA is copied, so that each of the resulting two cells will inherit the DNA sequence. A portion of a DNA molecule that specifies a single functional unit is called a gene. Within cells, the long strands of DNA form condensed structures called chromosomes. Organisms inherit genetic material from their parents in the form of homologous chromosomes, containing a unique combination of DNA sequences that code for genes; the specific location of a DNA sequence within a chromosome is known as a locus. If the DNA sequence at a particular locus varies between individuals, the different forms of this sequence are called alleles. DNA sequences can change through mutations.
If a mutation occurs within a gene, the new allele may affect the trait that the gene controls, altering the phenotype of the organism. However, while this simple correspondence between an allele and a trait works in some cases, most traits are more complex and are controlled by multiple interacting genes within and among organisms. Developmental biologists suggest that complex interactions in genetic networks and communication among cells can lead to heritable variations that may underlie some of the mechanics in developmental plasticity and canalization. Recent findings have confirmed important examples of heritable changes that cannot be explained by direct agency of the DNA molecule; these phenomena are classed as epigenetic inheritance systems that are causally or independently evolving over genes. Research into modes and mechanisms of epigenetic inheritance is still in its scientific infancy, this area of research has attracted much recent activity as it broadens the scope of heritability and evolutionary biology in general.
DNA methylation marking chromatin, self-sustaining metabolic loops, gene silencing by RNA interference, the three dimensional conformation of proteins are areas where epigenetic inheritance systems have been discovered at the organismic level. Heritability may occur at larger scales. For example, ecological inheritance through the process of niche construction is defined by the regular and repeated activities of organisms in their environment; this generates a legacy of effect that modifies and feeds back into the selection regime of subsequent generations. Descendants inherit genes plus environmental characteristics generated by the ecological actions of ancestors. Other examples of heritability in evolution that are not under the direct control of genes include the inheritance of cultural traits, group heritability, symbiogenesis; these examples of heritability that operate above the gene are covered broadly under the title of multilevel or hierarchical selection, a subject of intense debate in the history of evolutionary science.
When Charles Darwin proposed his theory of evolution in 1859, one of its major problems was the lack of an underlying mechanism for heredity. Darwin believed in the inheritance of acquired traits. Blending inheritance would lead to uniformity across populations in only a few generations and would remove variation from a population on which natural selection could act; this led to Darwin adopting some Lamarckian ideas in editions of On the Origin of Species and his biological works. Darwin's primary approach to heredity was to outline how it appeared to work rather than suggesting mechanisms. Darwin's initial model of heredity was adopted by, heavily modified by, his cousin Francis Galton, who laid the framework for the biometric school of heredity. Galton found no evidence to support the aspects of Darwin's pangenesis model, which relied on acquired traits; the inheritance of acquired traits was shown to have little basis in the 1880s when August Weismann cut the tails off many generations of mice and found that their offspring continued to develop tails.
Scientists in Antiquity had a variety of ideas about heredity: Theophrastus proposed that male flowers caused f
Tacrolimus known as fujimycin or FK506, is an immunosuppressive drug used after allogeneic organ transplant to lower the risk of organ rejection. It achieves this by inhibiting the production of interleukin-2, a molecule that promotes the development and proliferation of T cells, which are vital to the body's learned immune response. Tacrolimus is used in the treatment of other T cell-mediated diseases such as eczema, severe refractory uveitis after bone marrow transplants, exacerbations of minimal change disease, Kimura's disease, the skin condition vitiligo. Chemically it is a 23-membered macrolide lactone, first discovered in 1987 from the fermentation broth of a Japanese soil sample that contained the bacterium Streptomyces tsukubaensis. Tacrolimus is used to treat dry eye syndrome in cats and dogs, it is much more potent. Immunosuppression with tacrolimus was associated with a lower rate of acute rejection compared with ciclosporin-based immunosuppression in one study. Clinical outcome is better with tacrolimus than with ciclosporin during the first year of liver transplantation.
Long-term outcome has not been improved to the same extent. Tacrolimus is prescribed as part of a post-transplant cocktail including steroids, IL-2 receptor inhibitors such as basiliximab. Dosages are titrated to target blood levels. In recent years, tacrolimus has been used to suppress the inflammation associated with ulcerative colitis, a form of inflammatory bowel disease. Although exclusively used in trial cases only, tacrolimus has shown to be effective in the suppression of outbreaks of UC; as an ointment, tacrolimus is used in particular atopic dermatitis. It suppresses inflammation in a similar way to steroids, is as effective as a mid-potency steroid. An important advantage of tacrolimus is that, unlike steroids, it does not cause skin thinning, or other steroid related side effects, it is applied on the active lesions until they heal off, but may be used continuously in low doses, applied to the thinner skin over the face and eyelids. Clinical trials of up to one year have been conducted.
It has been used to treat segmental vitiligo in children in areas on the face. Lupus Nephritis Tacrolimus has been shown to reduce the risk of serious infection in lupus nephritis, when compared to other agents. Contraindications and precautions include: Breast-feeding Hepatic disease Immunosuppression Infants Infection Neoplastic disease, such as: Skin cancer Lung cancer Oliguria Pregnancy QT interval prolongation Sunlight exposure Grapefruit juice Occlusive dressing Known or suspected malignant lesions Netherton's syndrome or similar skin diseases Certain skin infections Side effects can be severe and include infection, cardiac damage, blurred vision and kidney problems, hypomagnesemia, diabetes mellitus, lung damage, various neuropsychiatric problems such as loss of appetite, posterior reversible encephalopathy syndrome, weakness, vivid nightmares, neuropathy, seizures and catatonia. In addition, it may increase the severity of existing fungal or infectious conditions such as herpes zoster or polyoma viral infections.
In people receiving immunosuppressants to reduce transplant graft rejection, an increased risk of malignancy is a recognised complication. The most common cancers are non-Hodgkin's skin cancers; the risk appears to be related to the duration of treatment. The most common adverse events associated with the use of topical tacrolimus ointments if used over a wide area, include a burning or itching sensation on the initial applications, with increased sensitivity to sunlight and heat on the affected areas. Less common are flu-like symptoms, headache and burning eyes. Tacrolimus and a related drug for eczema were suspected of carrying a cancer risk, though the matter is still a subject of controversy; the FDA issued a health warning in March 2005 for the drug, based on animal models and a small number of patients. Until further human studies yield more conclusive results, the FDA recommends that users be advised of the potential risks. However, current practice by UK dermatologists is not to consider this a significant real concern and they are recommending the use of these new drugs.
Like cyclosporin, it has a wide range of interactions. Tacrolimus is metabolised by the cytochrome P450 system of liver enzymes, there are many substances that interact with this system and induce or inhibit the system's metabolic activity. Interactions include that with grapefruit; as infections are a major cause of morbidity and mortality in the post-transplant patient, the most reported interactions include interactions with anti-microbial drugs. Macrolide antibiotics including erythromycin and clarithromycin, as well as several of the newer classes of antifungals of the azole class, increase tacrolimus levels by competing for cytochrome enzymes. Tacrolimus is a macrolide calcineurin inhibitor. In T-cells, activation of the T-cell receptor increases intracellular calcium, which acts via calmodulin to activate calcineurin. Calcineurin dephosphorylates the transcription factor nuclear factor of activated T-cells, which moves to the nucleus of the T-cell and i
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms, an allergen is an antigen, capable of stimulating a type-I hypersensitivity reaction in atopic individuals through Immunoglobulin E responses. Most humans mount significant Immunoglobulin E responses only as a defense against parasitic infections. However, some individuals may respond to many common environmental antigens; this hereditary predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity. Sensitivities vary from one person to another. A broad range of substances can be allergens to sensitive individuals. Allergens can be found in a variety of sources, such as dust mite excretion, pet dander, or royal jelly. Food allergies are not as common as food sensitivity, but some foods such as peanuts, nuts and shellfish are the cause of serious allergies in many people.
The United States Food and Drug Administration does recognize eight foods as being common for allergic reactions in a large segment of the sensitive population. These include peanuts, tree nuts, milk, fish and their derivatives, soy and their derivatives, as well as sulfites at 10ppm and over. See the FDA website for complete details. Other countries, in view of the differences in the genetic profiles of their citizens and different levels of exposure to specific foods due to different dietary habits, the "official" allergen list will change. Canada recognizes all eight of the allergens recognized by the US, recognizes sesame seeds, mustard; the European Union additionally recognizes other gluten-containing cereals as well as celery and lupin. Another allergen is urushiol, a resin produced by poison ivy and poison oak, which causes the skin rash condition known as urushiol-induced contact dermatitis by changing a skin cell's configuration so that it is no longer recognized by the immune system as part of the body.
Various trees and wood products such as paper, cardboard, MDF etc. can cause mild to severe allergy symptoms through touch or inhalation of sawdust such as asthma and skin rash. An allergic reaction can be caused by any form of direct contact with the allergen—consuming food or drink one is sensitive to, breathing in pollen, perfume or pet dander, or brushing a body part against an allergy-causing plant. Other common causes of serious allergy are wasp, fire ant and bee stings and latex. An serious form of an allergic reaction is called anaphylaxis. One form of treatment is the administration of sterile epinephrine to the person experiencing anaphylaxis, which suppresses the body's overreaction to the allergen, allows for the patient to be transported to a medical facility. In addition to foreign proteins found in foreign serum and vaccines, common allergens include: Animal products Fel d 1 fur and dander cockroach calyx wool dust mite excretion Drugs penicillin sulfonamides salicylates Foods celery and celeriac corn or maize eggs fruit pumpkin, egg-plant legumes beans peas peanuts soybeans milk seafood sesame soy tree nuts pecans almonds wheat Insect stings bee sting venom wasp sting venom mosquito stings Mold spores Top 5 allergens discovered in patch tests in 2005–06: nickel sulfate Balsam of Peru fragrance mix I quaternium-15, neomycin.
Metals Nickel Chromium Other latex wood Plant pollens grass — ryegrass, timothy-grass weeds — ragweed, nettle, Artemisia vulgaris, Chenopodium album, sorrel trees — birch, hazel, Aesculus, poplar, Tilia, Ashe juniper, Alstonia scholaris Seasonal allergy symptoms are experienced during specific parts of the year during spring, summer or fall when certain trees or grasses pollinate. This depends on the kind of grass. For instance, some trees such as oak and maple pollinate in the spring, while grasses such as Bermuda and orchard pollinate in the summer. Grass allergy is linked to hay fever because their symptoms and causes are somehow similar to each other. Symptoms include rhinitis, which causes sneezing and a runny nose, as well as allergic conjunctivitis, which includes watering and itchy eyes. An initial tickle on the roof of the mouth or in the back of the throat may be experienced. Depending on the season, the symptoms may be more severe and people may experience coughing and irritability.
A few people become depressed, lose their appetite, or have problems sleeping. Moreover, since the sinuses may become congested, some people experience headaches. If both parents suffered from allergies in the past, there is a 66% chance for the individual to suffer from seasonal allergies, the risk lowers to 60% if just one parent had suffered from allergies; the immune system has strong influence on seasonal allergies, since it reacts differently to diverse allergens like pollen. When an allergen enters the body of an individual, predisposed to allergies, it triggers an immune reaction and the production of antibodies; these allergen antibodies migrate to mast cells lining the nose and lungs. When an allergen drifts into the nose more than once, mast cells release a slew of chemicals or histamines that irritate and inflame the moist membranes lining the nose and produ
The Ancient Greek language includes the forms of Greek used in Ancient Greece and the ancient world from around the 9th century BCE to the 6th century CE. It is roughly divided into the Archaic period, Classical period, Hellenistic period, it is succeeded by medieval Greek. Koine is regarded as a separate historical stage of its own, although in its earliest form it resembled Attic Greek and in its latest form it approaches Medieval Greek. Prior to the Koine period, Greek of the classic and earlier periods included several regional dialects. Ancient Greek was the language of Homer and of fifth-century Athenian historians and philosophers, it has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article contains information about the Epic and Classical periods of the language. Ancient Greek was a pluricentric language, divided into many dialects; the main dialect groups are Attic and Ionic, Aeolic and Doric, many of them with several subdivisions.
Some dialects are found in standardized literary forms used in literature, while others are attested only in inscriptions. There are several historical forms. Homeric Greek is a literary form of Archaic Greek used in the epic poems, the "Iliad" and "Odyssey", in poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic and other Classical-era dialects; the origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between the divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period, they differ in some of the detail. The only attested dialect from this period is Mycenaean Greek, but its relationship to the historical dialects and the historical circumstances of the times imply that the overall groups existed in some form. Scholars assume that major Ancient Greek period dialect groups developed not than 1120 BCE, at the time of the Dorian invasion—and that their first appearances as precise alphabetic writing began in the 8th century BCE.
The invasion would not be "Dorian" unless the invaders had some cultural relationship to the historical Dorians. The invasion is known to have displaced population to the Attic-Ionic regions, who regarded themselves as descendants of the population displaced by or contending with the Dorians; the Greeks of this period believed there were three major divisions of all Greek people—Dorians and Ionians, each with their own defining and distinctive dialects. Allowing for their oversight of Arcadian, an obscure mountain dialect, Cypriot, far from the center of Greek scholarship, this division of people and language is quite similar to the results of modern archaeological-linguistic investigation. One standard formulation for the dialects is: West vs. non-west Greek is the strongest marked and earliest division, with non-west in subsets of Ionic-Attic and Aeolic vs. Arcadocypriot, or Aeolic and Arcado-Cypriot vs. Ionic-Attic. Non-west is called East Greek. Arcadocypriot descended more from the Mycenaean Greek of the Bronze Age.
Boeotian had come under a strong Northwest Greek influence, can in some respects be considered a transitional dialect. Thessalian had come under Northwest Greek influence, though to a lesser degree. Pamphylian Greek, spoken in a small area on the southwestern coast of Anatolia and little preserved in inscriptions, may be either a fifth major dialect group, or it is Mycenaean Greek overlaid by Doric, with a non-Greek native influence. Most of the dialect sub-groups listed above had further subdivisions equivalent to a city-state and its surrounding territory, or to an island. Doric notably had several intermediate divisions as well, into Island Doric, Southern Peloponnesus Doric, Northern Peloponnesus Doric; the Lesbian dialect was Aeolic Greek. All the groups were represented by colonies beyond Greece proper as well, these colonies developed local characteristics under the influence of settlers or neighbors speaking different Greek dialects; the dialects outside the Ionic group are known from inscriptions, notable exceptions being: fragments of the works of the poet Sappho from the island of Lesbos, in Aeolian, the poems of the Boeotian poet Pindar and other lyric poets in Doric.
After the conquests of Alexander the Great in the late 4th century BCE, a new international dialect known as Koine or Common Greek developed based on Attic Greek, but with influence from other dialects. This dialect replaced most of the older dialects, although Doric dialect has survived in the Tsakonian language, spoken in the region of modern Sparta. Doric has passed down its aorist terminations into most verbs of Demotic Greek. By about the 6th century CE, the Koine had metamorphosized into Medieval Greek. Ancient Macedonian was an Indo-European language at least related to Greek, but its exact relationship is unclear because of insufficient data: a dialect of Greek; the Macedonian dialect (or l
Immunoglobulin E is a type of antibody that has only been found in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains and two light chains, with the ε chain containing 4 Ig-like constant domains. IgE's main function is immunity to parasites such as helminths like Schistosoma mansoni, Trichinella spiralis, Fasciola hepatica. IgE is utilized during immune defense against certain protozoan parasites such as Plasmodium falciparum. IgE has an essential role in type I hypersensitivity, which manifests in various allergic diseases, such as allergic asthma, most types of sinusitis, allergic rhinitis, food allergies, specific types of chronic urticaria and atopic dermatitis. IgE plays a pivotal role in responses to allergens, such as: anaphylactic drugs, bee stings, antigen preparations used in desensitization immunotherapy. Although IgE is the least abundant isotype—blood serum IgE levels in a normal individual are only 0.05% of the Ig concentration, compared to 75% for the IgGs at 10 mg/ml, which are the isotypes responsible for most of the classical adaptive immune response—it is capable of triggering the most powerful inflammatory reactions.
IgE was discovered in 1966 and 1967 by two independent groups: Kimishige Ishizaka and his wife Teruko Ishizaka at the Children's Asthma Research Institute and Hospital in Denver, by S. G. O Johansson and Hans Bennich in Sweden, their joint paper was published in April 1969. IgE primes the IgE-mediated allergic response by binding to Fc receptors found on the surface of mast cells and basophils. Fc receptors are found on eosinophils, monocytes and platelets in humans. There are two types of Fcε receptors: FcεRI, the high-affinity IgE receptor FcεRII known as CD23, the low-affinity IgE receptorIgE can upregulate the expression of both types of Fcε receptors. FcεRI is expressed on mast cells and the antigen-presenting dendritic cells in both mice and humans. Binding of antigens to IgE bound by the FcεRI on mast cells causes cross-linking of the bound IgE and the aggregation of the underlying FcεRI, leading to degranulation and the secretion of several types of type 2 cytokines like IL-3 and Stem Cell Factor which both help the mast cells survive and accumulate in tissue, IL-4, IL-5 and IL-13 as well as IL-33 which in turn activate group 2-innate lymphoid cells.
Basophils, which share a common haemopoietic progenitor with mast cells, upon the cross-linking of their surface bound IgE by antigens release type 2 cytokines like interleukin-4 and interleukin-13 and other inflammatory mediators. The low-affinity receptor is always expressed on B cells. There has been an accumulating evidence in the past decade on the physiological role of IgE: this isotype has co-evolved with basophils and mast cells in the defence against parasites like helminths but may be effective in bacterial infections. Epidemiological research shows that IgE level is increased when infected by Schistosoma mansoni, Necator americanus, nematodes in humans, it is most beneficial in removal of hookworms from the lung. Although it is not yet well understood, IgE may play an important role in the immune system’s recognition of cancer, in which the stimulation of a strong cytotoxic response against cells displaying only small amounts of early cancer markers would be beneficial. If this were the case, anti-IgE treatments such as omalizumab might have some undesirable side effects.
However, a recent study, performed based on pooled analysis using comprehensive data from 67 phase I to IV clinical trials of omalizumab in various indications, concluded that a causal relationship between omalizumab therapy and malignancy is unlikely. Atopic individuals can have up to ten times the normal level of IgE in their blood. However, this may not be a requirement for symptoms to occur as has been seen in asthmatics with normal IgE levels in their blood—recent research has shown that IgE production can occur locally in the nasal mucosa. IgE that can recognise an allergen has a unique long-lived interaction with its high-affinity receptor FcεRI so that basophils and mast cells, capable of mediating inflammatory reactions, become "primed", ready to release chemicals like histamine and certain interleukins; these chemicals cause many of the symptoms we associate with allergy, such as airway constriction in asthma, local inflammation in eczema, increased mucus secretion in allergic rhinitis, increased vascular permeability, it is presumed, to allow other immune cells to gain access to tissues, but which can lead to a fatal drop in blood pressure as in anaphylaxis.
IgE is known to be elevated in various autoimmune disorders such as Lupus, Rheumatoid Arthritis & psoriasis, is theorized to be of pathogenetic importance in RA and SLE by eliciting a hypersensitivity reaction. Regulation of IgE levels through control of B cell differentiation to antibody-secreting plasma cells is thought to involve the "low-affinity" receptor FcεRII, or CD23. CD23 may allow facilitated antigen presentation, an IgE-dependent mechanism whereby B cells expressing CD23 are able to present allergen to specific T helper cells, causing the perpetuation of a Th2 response, one of the hallmarks o
Waldorf education known as Steiner education, is based on the educational philosophy of Rudolf Steiner, the founder of Anthroposophy. Its pedagogy strives to develop pupils' intellectual and practical skills in an integrated and holistic manner; the cultivation of pupils' imagination and creativity is a central focus. Individual teachers and schools have a great deal of autonomy in determining curriculum content, teaching methodology, governance. Qualitative assessments of student work are integrated into the daily life of the classroom, with quantitative testing playing a minimal role and standardized testing limited to what is required to enter post-secondary education; the first Waldorf school opened in 1919 in Germany. A century it has become the largest independent school movement in the world, with about 1,150 independent Waldorf schools, 1,800 kindergartens and 646 centers for special education located in 75 countries. There are a number of Waldorf-based public schools, charter schools and academies, homeschooling environments.
Public funding of Waldorf schools in English-speaking countries has met some road blocks due to widespread rejection of vaccines among the parents of Waldorf pupils and the mystical and antiquated nature of some of Steiner's theories. Several Waldorf schools in the UK have closed due to their administrations' failure to adhere to accepted standards of education; the first school based upon the ideas of Rudolf Steiner was opened in 1919 in response to a request from Emil Molt, the owner and managing director of the Waldorf-Astoria Cigarette Company in Stuttgart, Germany. This is the source of the name Waldorf, now trademarked in some countries when used in connection with the overall method that grew out of this original Waldorf school. Molt's proposed school would educate the children of employees of the factory. Molt was a follower of Anthroposophy, the esoteric spiritual movement based on the notion that an objectively comprehensible spiritual realm exists and can be observed by humans. Emil Molt was a close confidant of Rudolf Steiner, Anthroposophy's founder and spiritual leader.
Many of Steiner's ideas influenced the pedagogy of the original Waldorf school and still play a central role in modern Waldorf classrooms.. As the co-educational school served children from outside the factory, it included children from a diverse social spectrum, it was the first comprehensive school in Germany. Waldorf education became more known in Britain in 1922 through lectures Steiner gave at a conference at Oxford University on educational methods. Two years on his final trip to Britain at Torquay in 1924, Steiner delivered a Waldorf teacher training course; the first school in England was founded in 1925. By the 1930s, numerous schools inspired by the original and/or Steiner's pedagogical principles had opened in Germany, the Netherlands, Austria, the United States, England. From 1933 to 1945, political interference from the Nazi regime limited and closed most Waldorf schools in Europe, with the exception of the British and some Dutch schools; the affected schools were reopened after the Second World War, though those in Soviet-dominated Eastern Germany were closed again a few years by the Communist German Democratic Republic government.
In North America, the number of Waldorf schools increased from nine in the United States and one in Canada in 1967 to around 200 in the United States and over 20 in Canada as of 2014. There are 29 Steiner schools in the United Kingdom and 3 in the Republic of Ireland. After the dissolution of the Soviet Union, Waldorf schools again began to proliferate in Central and Eastern Europe. Most many schools have opened in Asia in China. There are over 1,000 independent Waldorf schools worldwide; the structure of Waldorf education follows a theory of childhood development devised by Rudolf Steiner, utilizing three distinct learning strategies for each of three distinct developmental stages. These stages each last seven years, as Steiner believed human beings develop in seven-year-long spiritual cycles, he believed each stage was imbued with a different "sphere" - the Moon and Venus. Aside from these spiritual underpinnings, Steiner's seven-year stages are broadly similar to those described by Jean Piaget.
In other respects, Steiner's ideas are descended from educational theories developed by Comenius and Pestalozzi. The stated purpose of this approach is to awaken the "physical, emotional, cognitive and spiritual" aspects of each individual, fostering creative and inquisitive thought. Where is the book in which the teacher can read about what teaching is? The children themselves are this book. We should not learn to teach out of any book other than the one lying open before us and consisting of the children themselves. Waldorf pedagogical theory considers that during the first years of life children learn best by being immersed in an environment they can learn from through un-selfconscious imitation of practical activities; the early childhood curriculum therefore centers on experiential education, allowing children to learn by example, opportunities for imaginative play. The overall goal of the curriculum is to "imbue the child with a sense that the world is good."Waldorf preschools employ a regular daily routine that includes free play, artistic work (e.g. drawing