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Vegetation (pathology)
In medicine, a vegetation is an abnormal growth named for its similarity to natural vegetation. Vegetations are often associated with endocarditis. They can be made of fibrin and platelet Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby i ...s. Types Certain conditions are associated with specific vegetation patterns: References Medical terminology {{pathology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histopathology Of Vegetation Of Bacterial Endocarditis
Histopathology (compound of three Greek language, Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logy, -logia'' "study of") refers to the light microscope, microscopic examination of Tissue (biology), tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopathology refers to the examination of a biopsy or surgical Laboratory specimen, specimen by a pathology, pathologist, after the specimen has been processed and histological sections have been placed onto glass slides. In contrast, cytopathology examines free cells or tissue micro-fragments (as "cell blocks"). Collection of tissues Histopathological examination of tissues starts with surgery, biopsy, or autopsy. The tissue is removed from the Human body, body or plant, and then, often following expert dissection in the fresh state, placed in a fixation (histology), fixative which stabilizes the tissues to prevent Decomposition, decay. The most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetation
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader than the term ''flora'' which refers to species composition. Perhaps the closest synonym is plant community, but ''vegetation'' can, and often does, refer to a wider range of spatial scales than that term does, including scales as large as the global. Primeval redwood forests, coastal mangrove stands, sphagnum bogs, desert soil crusts, roadside weed patches, wheat fields, cultivated gardens and lawns; all are encompassed by the term ''vegetation''. The vegetation type is defined by characteristic dominant species, or a common aspect of the assemblage, such as an elevation range or environmental commonality. The contemporary use of ''vegetation'' approximates that of ecologist Frederic Clements' term earth cover, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the surfaces of intracardiac devices. Endocarditis is characterized by lesions, known as '' vegetations'', which is a mass of platelets, fibrin, microcolonies of microorganisms, and scant inflammatory cells. In the subacute form of infective endocarditis, the vegetation may also include a center of granulomatous tissue, which may fibrose or calcify. There are several ways to classify endocarditis. The simplest classification is based on cause: either ''infective'' or ''non-infective'', depending on whether a microorganism is the source of the inflammation or not. Regardless, the diagnosis of endocarditis is based on clinical features, investigations such as an echocardiogram, and blood cultures demonstrating the presence of endocarditis-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrin
Fibrin (also called Factor Ia) is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen, which causes it to polymerize. The polymerized fibrin, together with platelets, forms a hemostatic plug or clot over a wound site. When the lining of a blood vessel is broken, platelets are attracted, forming a platelet plug. These platelets have thrombin receptors on their surfaces that bind serum thrombin molecules, which in turn convert soluble fibrinogen in the serum into fibrin at the wound site. Fibrin forms long strands of tough insoluble protein that are bound to the platelets. Factor XIII completes the cross-linking of fibrin so that it hardens and contracts. The cross-linked fibrin forms a mesh atop the platelet plug that completes the clot. Fibrin was discovered by Marcello Malpighi in 1666. Role in disease Excessive generation of fibrin due to activation of the coagulation cascade leads to thrombos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelet
Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow or lung, which then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells. One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and, unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: ''adhesion''. Second, they change shape, turn on receptors and secrete chemical messengers: ''activatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infective Endocarditis
Infective endocarditis is an infection of the inner surface of the heart, usually the valves. Signs and symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cell count. Complications may include backward blood flow in the heart, heart failure – the heart struggling to pump a sufficient amount of blood to meet the body's needs, abnormal electrical conduction in the heart, stroke, and kidney failure. The cause is typically a bacterial infection and less commonly a fungal infection. Risk factors include valvular heart disease, including rheumatic disease, congenital heart disease, artificial valves, hemodialysis, intravenous drug use, and electronic pacemakers. The bacteria most commonly involved are streptococci or staphylococci. Diagnosis is suspected based on symptoms and supported by blood cultures or ultrasound of the heart. There is also a noninfective form of endocarditis. The usefulness of antibiotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aureus'' (MRSA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheumatic Fever
Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful joints, involuntary muscle movements, and occasionally a characteristic non-itchy rash known as erythema marginatum. The heart is involved in about half of the cases. Damage to the heart valves, known as rheumatic heart disease (RHD), usually occurs after repeated attacks but can sometimes occur after one. The damaged valves may result in heart failure, atrial fibrillation and infection of the valves. Rheumatic fever may occur following an infection of the throat by the bacterium ''Streptococcus pyogenes''. If the infection is left untreated, rheumatic fever occurs in up to three percent of people. The underlying mechanism is believed to involve the production of antibodies against a person's own tissues. Due to their genetics, some peo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Pyogenes
''Streptococcus pyogenes'' is a species of Gram-positive, aerotolerant bacteria in the genus ''Streptococcus''. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They are clinically important for humans, as they are an infrequent, but usually pathogenic, part of the skin microbiota that can cause Group A streptococcal infection. ''S. pyogenes'' is the predominant species harboring the Lancefield group A antigen, and is often called group A ''Streptococcus'' (GAS). However, both '' Streptococcus dysgalactiae'' and the '' Streptococcus anginosus'' group can possess group A antigen as well. Group A streptococci, when grown on blood agar, typically produce small (2–3 mm) zones of beta-hemolysis, a complete destruction of red blood cells. The name group A (beta-hemolytic) ''Streptococcus'' (GABHS) is thus also used. The species name is derived from Greek words meaning 'a chain' () of berries ( a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libman–Sacks Endocarditis
Libman–Sacks endocarditis is a form of non-bacterial endocarditis that is seen in association with systemic lupus erythematosus, antiphospholipid syndrome, and malignancies. It is one of the most common cardiac manifestations of lupus (the most common being pericarditis). Presentation Libman–Sacks endocarditis itself is typically asymptomatic. Affected persons most commonly present with embolisms secondary to dislodged vegetations. However, in some cases, severe valvular dysfunction may develop. People with systemic lupus erythematosus may present with other symptoms of the underlying diseases that give rise to Libman–Sacks endocarditis. Complications Libman–Sacks endocarditis may result in arterial emboli, valvular insufficiency, and heart failure. Infective endocarditis occurs more frequently with those with systemic lupus erythematosus. Emboli Vegetations occurring in the context of Libman–Sacks endocarditis may dislodge to form emboli and cause embolism (incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Lupus Erythematosus
Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. The cause of SLE is not clear. It is thought to involve a mixture of genetics combined with environmental factors. Among identical twins, if one is affected there is a 24% chance the other one will also develop the disease. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increase a person's risk. The mechanism involves an immune response by autoantibodies against a person's own tissues. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonbacterial Thrombotic Endocarditis
Nonbacterial thrombotic endocarditis (NBTE) is a form of endocarditis in which small sterile vegetations are deposited on the valve leaflets. Formerly known as marantic endocarditis, which comes from the Greek , meaning "wasting away". The term "marantic endocarditis" is still sometimes used to emphasize the association with a wasting state such as cancer. Risk factors Marantic vegetations are often associated with previous rheumatic fever. Other risk factors include: * hypercoagulable states * malignant cancers, especially mucin-producing adenocarcinomas (most commonly associated with pancreatic adenocarcinomas) * systemic lupus erythematosus: Referred to as Libman-Sacks endocarditis * trauma (e.g., catheters) Valve predilection The disease affects the valves with following predilection: mitral valve > aortic valve > tricuspid valve > pulmonary valve Histopathology Grossly, vegetations form along lines of valve closure and are generally symmetric with a smooth or verruc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
