Pathology
Pathology is the study of the causes and effects of disease or injury. The word pathology refers to the study of disease in general, incorporating a wide range of bioscience research fields and medical practices. However, when used in the context of modern medical treatment, the term is used in a more narrow fashion to refer to processes and tests which fall within the contemporary medical field of "general pathology," an area which includes a number of distinct but inter-related medical specialties that diagnose disease through analysis of tissue and body fluid samples. Idiomatically, "a pathology" may refer to the predicted or actual progression of particular diseases, the affix path is sometimes used to indicate a state of disease in cases of both physical ailment and psychological conditions. A physician practicing pathology is called a pathologist; as a field of general inquiry and research, pathology addresses four components of disease: cause, mechanisms of development, structural alterations of cells, the consequences of changes.
In common medical practice, general pathology is concerned with analyzing known clinical abnormalities that are markers or precursors for both infectious and non-infectious disease and is conducted by experts in one of two major specialties, anatomical pathology and clinical pathology. Further divisions in specialty exist on the basis of the involved sample types and physiological systems, as well as on the basis of the focus of the examination. Pathology is a significant field in medical research; the study of pathology, including the detailed examination of the body, including dissection and inquiry into specific maladies, dates back to antiquity. Rudimentary understanding of many conditions was present in most early societies and is attested to in the records of the earliest historical societies, including those of the Middle East and China. By the Hellenic period of ancient Greece, a concerted causal study of disease was underway, with many notable early physicians having developed methods of diagnosis and prognosis for a number of diseases.
The medical practices of the Romans and those of the Byzantines continued from these Greek roots, but, as with many areas of scientific inquiry, growth in understanding of medicine stagnated some after the Classical Era, but continued to develop throughout numerous cultures. Notably, many advances were made in the medieval era of Islam, during which numerous texts of complex pathologies were developed based on the Greek tradition. So, growth in complex understanding of disease languished until knowledge and experimentation again began to proliferate in the Renaissance and Baroque eras, following the resurgence of the empirical method at new centers of scholarship. By the 17th century, the study of microscopy was underway and examination of tissues had led British Royal Society member Robert Hooke to coin the word "cell", setting the stage for germ theory. Modern pathology began to develop as a distinct field of inquiry during the 19th Century through natural philosophers and physicians that studied disease and the informal study of what they termed “pathological anatomy” or “morbid anatomy”.
However, pathology as a formal area of specialty was not developed until the late 19th and early 20th centuries, with the advent of detailed study of microbiology. In the 19th century, physicians had begun to understand that disease-causing pathogens, or "germs" existed and were capable of reproduction and multiplication, replacing earlier beliefs in humors or spiritual agents, that had dominated for much of the previous 1,500 years in European medicine. With the new understanding of causative agents, physicians began to compare the characteristics of one germ’s symptoms as they developed within an affected individual to another germ’s characteristics and symptoms; this realization led to the foundational understanding that diseases are able to replicate themselves, that they can have many profound and varied effects on the human host. To determine causes of diseases, medical experts used the most common and accepted assumptions or symptoms of their times, a general principal of approach that persists into modern medicine.
Modern medicine was advanced by further developments of the microscope to analyze tissues, to which Rudolf Virchow gave a significant contribution, leading to a slew of research developments. By the late 1920s to early 1930s pathology was deemed a medical specialty. Combined with developments in the understanding of general physiology, by the beginning of the 20th century, the study of pathology had begun to split into a number of rarefied fields and resulting in the development of large number of modern specialties within pathology and related disciplines of diagnostic medicine; the term pathology comes from the Ancient Greek roots of pathos, meaning "experience" or "suffering" and -logia, "study of". The modern practice of pathology is divided into a number of subdisciplines within the discrete but interconnected aims of biological research and medical practice. Biomedical research into disease incorporates the
Osler's node
Osler's nodes are painful, raised lesions found on the hands and feet. They are associated with a number of conditions, including infective endocarditis, are caused by immune complex deposition, their presence is one definition of Osler's sign. Osler's nodes result from the deposition of immune complexes; the resulting inflammatory response leads to swelling and pain that characterize these lesions. The nodes are indicative of subacute bacterial endocarditis. 10–25% of endocarditis patients will have Osler's nodes. Other signs of endocarditis include Janeway lesions; the latter, which occur on the palms and soles, can be differentiated from Osler's nodes because they are non-tender. Osler's nodes can be seen in Systemic lupus erythematosus Marantic endocarditis Disseminated gonococcal infection Distal to infected arterial catheter Osler's nodes are named after Sir William Osler who described them in the early 20th century. Picture of Osler's nodes and Janeway's lesions
Degloving
A degloving injury is a type of avulsion in which an extensive section of skin is torn off the underlying tissue, severing its blood supply. It is named by analogy to the process of removing a glove. Degloving injuries affect the extremities and limbs. Any injury which would induce degloving of the head or torso is to be lethal. However, controlled facial degloving is featured in plastic surgery. Degloving injuries invariably require major surgical interventions. Treatment options include replantation or revascularization of the degloved skins, or when these are not possible, skin grafts or skin flaps. While the preservation of the extremities and limbs is preferred, in some cases amputations may be advised or required. Post-operative physiotherapy is of particular importance for degloving injuries involving the hand. Many small mammals are able to induce degloving of their tails to escape capture. Report on degloving injuries in children
Bullseye (target)
The bullseye, or bull's-eye, is the centre of a shooting target, by extension the name given to any shot that hits the bullseye. By extension, the word bullseye can refer to any design or pattern featuring prominent concentric circles, visually suggesting an archery target, "hitting the bullseye" is a term for an unexpectedly good success. In some archery traditions the term "gold" is used in preference to "bullseye". Hitting the most central ring of an international target is worth 10 points, or an Imperial target 9 points in target archery. In Japanese Kyūdō it is called "zuboshi". In darts it is 5 foot 8 inches above the floor. Before the start of a match players throw closest to the bull to decide who has the advantage of throwing first. An inner bullseye is a smaller, inner circle and counts for 50 points while an outer bull is worth 25 points. Two treble 20s when combined with an inner bullseye is worth 170 points in darts, the highest possible checkout. In the World Grand Prix, which has a double start format, an inner bullseye can begin a leg.
In the dart golf game, the bullseye is used as part of a three-part tie breaker that includes the treble twenty. Hitting three bullseyes in darts is known as the "Alan Evans shot". Bullseye Roundel, a round shape in heraldry Bullseye, a British game show based on darts
Ablation
Ablation is removal of material from the surface of an object by vaporization, chipping, or other erosive processes. Examples of ablative materials are described below, include spacecraft material for ascent and atmospheric reentry and snow in glaciology, biological tissues in medicine and passive fire protection materials. Biological ablation is the removal of a biological functionality. Genetic ablation is another term for gene silencing, in which gene expression is abolished through the alteration or deletion of genetic sequence information. In cell ablation, individual cells in a population or culture are removed. Both can be used as experimental tools, as in loss-of-function experiments. In glaciology and meteorology, ablation—the opposite of accumulation—refers to all processes that remove snow, ice, or water from a glacier or snowfield. Ablation refers to the melting of snow or ice that runs off the glacier, sublimation, calving, or erosive removal of snow by wind. Air temperature is the dominant control of ablation, with precipitation exercising secondary control.
In a temperate climate during ablation season, ablation rates average around 2 mm/h. Where solar radiation is the dominant cause of snow ablation, characteristic ablation textures such as suncups and penitentes may develop on the snow surface. Ablation can refer either to the processes removing ice and snow or to the quantity of ice and snow removed. Debris-covered glaciers have been shown to impact the ablation process. There is a thin debris layer that can be located on the top of glaciers that intensifies the ablation process below the ice; the debris-covered parts of a glacier, experiencing ablation are sectioned into three categories which include ice cliffs and debris. These three sections allow scientists to measure the heat digested by the debris-covered area and is calculated; the calculations are dependent on the area and net absorbed heat amounts in regards to the entire debris-covered zones. These types of calculations are done to various glaciers to understand and analyze future patterns of melting.
Moraine is moved by natural processes that allow for down-slope movement of materials on the glacier body. It is noted that if the slope of a glacier is too high the debris will continue to move along the glacier to a further location; the sizes and locations of glaciers vary around the world, so depending on the climate and physical geography the varieties of debris can differ. The size and magnitude of the debris is dependent on the area of glacier and can vary from dust-size fragments to blocks as large as a house. There has been many experiments done to demonstrate the effect of debris on the surface of glaciers. Yoshiyuki Fujii, a professor at the National Institute of Polar Research designed an experiment that showed ablation rate was accelerated under a thin debris layer and was retarded under a thick one as compared with that of a natural snow surface; this science is significant due to the importance of long-term availability of water resources and assess glacier response to climate change.
Natural resource availability is a major drive behind research conducted in regards to the ablation process and overall study of glaciers. Laser ablation is affected by the nature of the material and its ability to absorb energy, therefore the wavelength of the ablation laser should have a minimum absorption depth. While these lasers can average a low power, they can offer peak intensity and fluence given by: Intensity = average power focal spot area Peak intensity = peak power focal spot area Fluence = laser pulse energy focal spot area while the peak power is Peak power = pulse energy pulse duration {\displaystyle ={\frac {(\
Amino acid
Amino acids are organic compounds containing amine and carboxyl functional groups, along with a side chain specific to each amino acid. The key elements of an amino acid are carbon, hydrogen and nitrogen, although other elements are found in the side chains of certain amino acids. About 500 occurring amino acids are known and can be classified in many ways, they can be classified according to the core structural functional groups' locations as alpha-, beta-, gamma- or delta- amino acids. In the form of proteins, amino acid residues form the second-largest component of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. In biochemistry, amino acids having both the amine and the carboxylic acid groups attached to the first carbon atom have particular importance, they are known as α-amino acids. They include the 22 proteinogenic amino acids, which combine into peptide chains to form the building-blocks of a vast array of proteins.
These are all L-stereoisomers, although a few D-amino acids occur in bacterial envelopes, as a neuromodulator, in some antibiotics. Twenty of the proteinogenic amino acids are encoded directly by triplet codons in the genetic code and are known as "standard" amino acids; the other two are selenocysteine, pyrrolysine. Pyrrolysine and selenocysteine are encoded via variant codons. N-formylmethionine is considered as a form of methionine rather than as a separate proteinogenic amino acid. Codon–tRNA combinations not found in nature can be used to "expand" the genetic code and form novel proteins known as alloproteins incorporating non-proteinogenic amino acids. Many important proteinogenic and non-proteinogenic amino acids have biological functions. For example, in the human brain and gamma-amino-butyric acid are the main excitatory and inhibitory neurotransmitters. Hydroxyproline, a major component of the connective tissue collagen, is synthesised from proline. Glycine is a biosynthetic precursor to porphyrins used in red blood cells.
Carnitine is used in lipid transport. Nine proteinogenic amino acids are called "essential" for humans because they cannot be produced from other compounds by the human body and so must be taken in as food. Others may be conditionally essential for medical conditions. Essential amino acids may differ between species; because of their biological significance, amino acids are important in nutrition and are used in nutritional supplements, fertilizers and food technology. Industrial uses include the production of drugs, biodegradable plastics, chiral catalysts; the first few amino acids were discovered in the early 19th century. In 1806, French chemists Louis-Nicolas Vauquelin and Pierre Jean Robiquet isolated a compound in asparagus, subsequently named asparagine, the first amino acid to be discovered. Cystine was discovered in 1810, although its monomer, remained undiscovered until 1884. Glycine and leucine were discovered in 1820; the last of the 20 common amino acids to be discovered was threonine in 1935 by William Cumming Rose, who determined the essential amino acids and established the minimum daily requirements of all amino acids for optimal growth.
The unity of the chemical category was recognized by Wurtz in 1865, but he gave no particular name to it. Usage of the term "amino acid" in the English language is from 1898, while the German term, Aminosäure, was used earlier. Proteins were found to yield amino acids after enzymatic acid hydrolysis. In 1902, Emil Fischer and Franz Hofmeister independently proposed that proteins are formed from many amino acids, whereby bonds are formed between the amino group of one amino acid with the carboxyl group of another, resulting in a linear structure that Fischer termed "peptide". In the structure shown at the top of the page, R represents a side chain specific to each amino acid; the carbon atom next to the carboxyl group is called the α–carbon. Amino acids containing an amino group bonded directly to the alpha carbon are referred to as alpha amino acids; these include amino acids such as proline which contain secondary amines, which used to be referred to as "imino acids". The alpha amino acids are the most common form found in nature, but only when occurring in the L-isomer.
The alpha carbon is a chiral carbon atom, with the exception of glycine which has two indistinguishable hydrogen atoms on the alpha carbon. Therefore, all alpha amino acids but glycine can exist in either of two enantiomers, called L or D amino acids, which are mirror images of each other. While L-amino acids represent all of the amino acids found in proteins during translation in the ribosome, D-amin
Bankart lesion
A Bankart lesion is an injury of the anterior glenoid labrum of the shoulder due to anterior shoulder dislocation. When this happens, a pocket at the front of the glenoid forms that allows the humeral head to dislocate into it, it is an indication for surgery and accompanied by a Hill-Sachs lesion, damage to the posterior humeral head. The Bankart lesion is named after English orthopedic surgeon Arthur Sydney Blundell Bankart. A bony Bankart is a Bankart lesion that includes a fracture in of the anterior-inferior glenoid cavity of the scapula bone; the diagnosis is initially made by a combination of physical exam and medical imaging, where the latter may be projectional radiography and/or MRI of the shoulder. The presence of intra-articular contrast allows for better evaluation of the glenoid labrum. Type V SLAP tears extends into the Bankart defect. Arthroscopic repair of Bankart injuries have good success rates, though nearly one-third of patients require further surgery for continued instability after the initial procedure in a study of young adults, with higher re-operation rates in those less than 20 years of age.
Options for repair include an arthroscopic technique or a more invasive open Latarjet procedure, with the open technique tending to have a lower incidence of recurrent dislocation, but a reduced range of motion following surgery. Terms for anatomical location Bankart lesion - orthop.washington.edu Bankart lesion - zadeh.co.uk
