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William George MacCallum
William George MacCallum (18 April 1874 – 3 February 1944) was a Canadian-American physician and pathologist. He was of Scottish descent and was born in Dunnville village in Canada, where his father was a physician. He was educated at the University of Toronto. He graduated with BA in 1894. Initially inclined towards Greeks as academic career, his father influenced him to enter medicine. He joined the second year of the first batch of medicine course in the Johns Hopkins Medical School, and became one of the first graduates of the institute in 1897. He was appointed assistant resident of pathology of the medical school in 1897, resident pathologist in 1901, soon after Associate Professor, and full Professor in 1908. Between 1909 and 1917 he held a twin position of Professor of Pathology at Columbia University and the NewYork–Presbyterian Hospital. From 1917 to 1943 he held the Chair of Pathogy at Johns Hopkins University. MacCallum discovered the existence of two forms (now kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunnville
Dunnville is an unincorporated community located near the mouth of the Grand River in Haldimand County, Ontario, Canada near the historic Talbot Trail. It was formerly an incorporated town encompassing the surrounding area with a total population of 12,000. History Dunnville was the site of a Cayuga settlement called ''Detgahnegaha'gó:wah''. The European settlement was originally built as the entrance to the Welland "feeder" canal and the town once boasted several water-powered mills and a once-bustling canal port. The feeder canal closed in the late 1880s and the last mill was destroyed and replaced with a condominium complex about ten years ago. There is an impassable dam at Dunnville which regulates the level of the Grand River at Port Maitland which, in the 19th century, also helped regulate the level of the Welland Canal (from 1829 until 1887 when the third canal began to intake its water directly from Lake Erie). Dunnville was incorporated as a village in 1860 and then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haemoproteus
''Haemoproteus'' is a genus of alveolates that are parasitic in birds, reptiles and amphibians. Its name is derived from Greek: ''Haima'', "blood", and ''Proteus'', a sea god who had the power of assuming different shapes. The name ''Haemoproteus'' was first used in the description of '' H. columbae'' in the blood of the pigeon '' Columba livia'' by Kruse in 1890. This was also the first description of this genus. Two other genera — '' Halteridium'' and '' Simondia'' — are now considered to be synonyms of ''Haemoproteus''. The protozoa are intracellular parasites that infect the erythrocytes. They are transmitted by blood sucking insects including mosquitoes, biting midges (''Culicoides''), louse flies (''Hippoboscidae'') and horse-flies (" tabanids", "tabanid flies"). Infection with this genus is sometimes known as pseudomalaria because of the parasites' similarities with ''Plasmodium'' species. Within the genus there are at least 173 species, 5 varieties and 1 subspeci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doctor Of Medicine
Doctor of Medicine (abbreviated M.D., from the Latin ''Medicinae Doctor'') is a medical degree, the meaning of which varies between different jurisdictions. In the United States, and some other countries, the M.D. denotes a professional degree. This generally arose because many in 18th-century medical professions trained in Scotland, which used the M.D. degree nomenclature. In England, however, Bachelor of Medicine, Bachelor of Surgery was used and eventually in the 19th century became the standard in Scotland too. Thus, in the United Kingdom, Ireland and other countries, the M.D. is a research doctorate, honorary doctorate or applied clinical degree restricted to those who already hold a professional degree (Bachelor's/Master's/Doctoral) in medicine. In those countries, the equivalent professional degree to the North American, and some others use of M.D., is still typically titled Bachelor of Medicine, Bachelor of Surgery ( M.B.B.S.). History The first medical degrees were a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in which case it is known as latent tuberculosis. Around 10% of latent infections progress to active disease which, if left untreated, kill about half of those affected. Typical symptoms of active TB are chronic cough with blood-containing mucus, fever, night sweats, and weight loss. It was historically referred to as consumption due to the weight loss associated with the disease. Infection of other organs can cause a wide range of symptoms. Tuberculosis is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze. People with Latent TB do not spread the disease. Active infection occurs more often in people with HIV/AIDS and in those who smoke. Diagnosis of active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest William Goodpasture
Ernest William Goodpasture (October 17, 1886 – September 20, 1960) was an American pathologist and physician. Goodpasture advanced the scientific understanding of the pathogenesis of infectious diseases, parasitism, and a variety of rickettsial and viral infections. Together with colleagues at Vanderbilt University, he invented methods for growing viruses and rickettsiae in chicken embryos and fertilized chicken eggs. This enabled the development of vaccines against influenza, chicken pox, smallpox, yellow fever, typhus, Rocky mountain spotted fever, and other diseases. He also described Goodpasture syndrome.Valentini, Rudolph PPediatric Anti-GBM Disease (Goodpasture Syndrome). Accessed 8-28-2009. Education and professional career Goodpasture was born in Clarksville, Tennessee, in 1886. He received his B.A. from Vanderbilt University in 1908. In 1912, Goodpasture graduated from Johns Hopkins School of Medicine with an M.D. degree. There, under professors William H. Welch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', '' Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pylorus
The pylorus ( or ), or pyloric part, connects the stomach to the duodenum. The pylorus is considered as having two parts, the ''pyloric antrum'' (opening to the body of the stomach) and the ''pyloric canal'' (opening to the duodenum). The ''pyloric canal'' ends as the ''pyloric orifice'', which marks the junction between the stomach and the duodenum. The orifice is surrounded by a sphincter, a band of muscle, called the ''pyloric sphincter''. The word ''pylorus'' comes from Greek πυλωρός, via Latin. The word ''pylorus'' in Greek means "gatekeeper", related to "gate" ( el, pyle) and is thus linguistically related to the word " pylon". Structure The pylorus is the furthest part of the stomach that connects to the duodenum. It is divided into two parts, the ''antrum'', which connects to the body of the stomach, and the ''pyloric canal'', which connects to the duodenum. Antrum The ''pyloric antrum'' is the initial portion of the pylorus. It is near the bottom of the stomach, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Contraction
Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as when holding something heavy in the same position. The termination of muscle contraction is followed by muscle relaxation, which is a return of the muscle fibers to their low tension-generating state. For the contractions to happen, the muscle cells must rely on the interaction of two types of filaments which are the thin and thick filaments. Thin filaments are two strands of actin coiled around each, and thick filaments consist of mostly elongated proteins called myosin. Together, these two filaments form myofibrils which are important organelles in the skeletal muscle system. Muscle contraction can also be described based on two variables: length and tension. A muscle contraction is described as isometric if the muscle tension changes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetany
Tetany or tetanic seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disorders that increase the action potential frequency of muscle cells or the nerves that innervate them. Muscle cramps caused by the disease tetanus are not classified as tetany; rather, they are due to a lack of inhibition to the neurons that supply muscles. Tetanic contractions (physiologic tetanus) are a broad range of muscle contraction types, of which tetany is only one. Signs and symptoms Tetany is characterized by contraction of distal muscles of the hands (carpal spasm with extension of interphalangeal joints and adduction and flexion of the metacarpophalangeal joints) and feet (pedal spasm) and is associated with tingling around the mouth and distally in the limbs. Causes * The usual cause of tetany is a deficiency of calcium. An excess of phosphate (high phosphate-to-calcium ratio) can also trigger the spasms. * Underfunction of the parathyroid gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parathyroid Gland
Parathyroid glands are small endocrine glands in the neck of humans and other tetrapods. Humans usually have four parathyroid glands, located on the back of the thyroid gland in variable locations. The parathyroid gland produces and secretes parathyroid hormone in response to a low blood calcium, which plays a key role in regulating the amount of calcium in the blood and within the bones. Parathyroid glands share a similar blood supply, venous drainage, and lymphatic drainage to the thyroid glands. Parathyroid glands are derived from the epithelial lining of the third and fourth pharyngeal pouches, with the superior glands arising from the fourth pouch and the inferior glands arising from the higher third pouch. The relative position of the inferior and superior glands, which are named according to their final location, changes because of the migration of embryological tissues. Hyperparathyroidism and hypoparathyroidism, characterized by alterations in the blood calcium levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thyroid is located at the front of the neck, below the Adam's apple. Microscopically, the functional unit of the thyroid gland is the spherical thyroid follicle, lined with follicular cells (thyrocytes), and occasional parafollicular cells that surround a lumen containing colloid. The thyroid gland secretes three hormones: the two thyroid hormones triiodothyronine (T3) and thyroxine (T4)and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis, and in children, growth and development. Calcitonin plays a role in calcium homeostasis. Secretion of the two thyroid hormones is regulated by thyroid-stimulating hormone (TSH), which is secreted from the anterior pituitary gland. TSH is regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
