{"title":"Chagas disease","authors":"M. Miles","doi":"10.1093/med/9780198746690.003.0170","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0170","url":null,"abstract":"\u0000 Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, is a zoonotic infection with many mammal host and vector species. It is transmitted to humans by contamination of mucous membranes or abraded skin with infected faeces of bloodsucking triatomine bugs, also by blood transfusion, organ transplantation, transplacentally, and orally by food contaminated with infective forms. It multiplies intracellularly (pseudocysts) as amastigotes in mammalian cells, particularly heart and smooth muscle, from which flagellated trypomastigotes emerge to reinvade cells or circulate in blood. Around 10 million people are infected in Latin America; imported cases and congenital cases may occur elsewhere. Proven methods of controlling domestic triatomine bugs include insecticide spraying (with pyrethroids), health education, community support, and house improvement. Serological surveillance of children detects residual endemic foci or congenital transmission and is vital for monitoring the success of control programmes. There is no vaccine.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132992612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The porphyrias","authors":"T. Cox","doi":"10.1093/med/9780198746690.003.0231","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0231","url":null,"abstract":"The porphyrias are a remarkable family of metabolic disorders characterized biochemically by overproduction of haem precursors, principally in the liver and bone marrow. The acute porphyrias are inborn errors of varying penetrance that affect enzymatic steps in a tightly regulated biosynthetic pathway for haem; nonacute acquired forms also occur in genetically predisposed individuals. Clinical presentation of acute porphyria—life-threatening neurovisceral attacks occur in four of the porphyrias: acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and Doss’ porphyria (5-aminolaevulinate dehydratase deficiency). These present with abdominal pain, psychiatric symptoms, and signs of sympathetic and hypothalamic autonomic overactivity, sometimes accompanied by convulsions and motor and sensory deficits. Diagnosis of acute porphyria—this is key to survival of an acute attack of porphyria, which can be suspected on the basis of the past history, in particular of photosensitivity or the intermittent discoloration of urine, and family history, and is confirmed by finding excess water-soluble haem precursors in urine. Management of acute porphyria—treatment of an acute porphyric attack mandates immediate withdrawal of inappropriate drugs and other precipitating factors; infusions of haem arginate or other licensed preparations of haem shorten life-threatening episodes and may be effective prophylaxis for recurrent porphyria in women with periodic attacks. The nonacute porphyrias are photosensitivity syndromes caused by excess photoactive macrocyclic porphyrins triggered especially by visible light in the blue–violet range. In the most severe form, manifestations are of severe blistering lesions on sun-exposed skin, particularly of the hands and face, with the formation of vesicles and bullae that may become infected. Healing may lead to loss of digits, scarring of the eyelids, nose, lips, and scalp, and occasionally blindness due to corneal scarring.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133415523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Introduction to palliative care","authors":"S. Salt","doi":"10.1093/med/9780198746690.003.0063","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0063","url":null,"abstract":"Palliative care shifts the focus of care from managing the underlying pathophysiological processes to one that looks at the individual and the impact of life-threatening illness on them and those important to them. It aims to prevent and relieve suffering by means of early identification, assessment, and treatment of pain and other problems, physical, psychosocial, and spiritual. It focuses on interventions which might improve an individual’s quality of life rather than alter the underlying disease process, and routinely extends support to those important to the individual both during that individual’s lifetime and into bereavement. Challenges to the provision of effective palliative care include prognostic uncertainty, the necessity for engaging in difficult conversations, and the need to deal with a variety of ethical issues.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"522 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115469987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Delirium","authors":"Bart Sheehan","doi":"10.1093/med/9780198746690.003.0627","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0627","url":null,"abstract":"Delirium is one of the most common psychiatric problems encountered in elderly medical inpatients. It involves a fluctuating cognitive impairment with reduced alertness and often with poorly formed delusions and/or visual hallucinations. The main differential diagnosis is from dementia, although delirium is more likely to develop in patients with existing dementia. Almost any medical condition that affects brain function may cause delirium. Infection is the most common cause, and it is important to consider prescribed drugs as a cause and to remember drug and alcohol withdrawal. Imperatives in management are first to keep the patient safe from harm (they may wander or put themselves in danger), and second to find and correct the cause. Urgent medical investigation and treatment is required as long periods of delirium put the patient at risk of harm, including permanent cognitive impairment.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117285293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Endocarditis","authors":"J. Harrison, J. Klein, W. Littler, B. Prendergast","doi":"10.1093/med/9780198746690.003.0358","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0358","url":null,"abstract":"Endocarditis predominantly affects the aortic and mitral valves; involvement of the tricuspid valve occurs in approximately one-fifth of cases and pulmonary valve involvement is rare. In the developing world rheumatic heart disease is the most common predisposing factor. In developed countries endocarditis is more common in older people with native valve disease and in patients with prosthetic valves and intracardiac devices (pacemakers and defibrillators). In these countries up to 50% of cases have no predisposing cardiac lesion and more cases are related to intravenous drug abuse and nosocomial infection related to invasive procedures. Mortality remains high (30%) despite advances in antimicrobial therapy and surgery, and at least 50% of cases require valve surgery. Early diagnosis, specialist management, and timely intervention are key to successful outcome.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116449299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Papillomaviruses and polyomaviruses","authors":"R. Viscidi, Chengxiang Tan, C. Fakhry","doi":"10.1093/med/9780198746690.003.0094","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0094","url":null,"abstract":"There are nearly 200 human papillomavirus types that infect epithelia of skin and mucous membranes. They infect only humans, and cause conditions including the following:\u0000 skin warts and verrucas, which are caused by types 1 and 2; infection initiated when, after minor skin abrasions, for example, the basal cells of the epithelium come in contact with infectious virus;\u0000 anogenital warts, which are caused by types 6 and 11; transmitted by direct sexual contact, these are the most common sexually transmitted infection; present clinically as multiple exophytic lesions or as subclinical flat lesions. They can be treated topically with podophyllin or imiquimod, or by ablative surgical methods. Recurrences are common. A highly efficacious prophylactic vaccine is available.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"59 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123304775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Percutaneous interventional cardiac procedures","authors":"Edward D. Follan","doi":"10.1093/med/9780198746690.003.0368","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0368","url":null,"abstract":"Percutaneous coronary intervention is the term applied to a variety of percutaneous, catheter-based procedures that accomplish revascularization by angioplasty (enlargement of a vessel lumen by modification of plaque structure), stenting (deployment of an internal armature or stent), atherectomy (removal or ablation of plaque), or thrombectomy (removal of thrombus). The most common single indication for percutaneous coronary intervention is acute coronary syndrome. Randomized trials have shown that direct intervention for ST-elevation myocardial infarction is superior to initial thrombolytic therapy when performed in appropriate centres, and it can be used as a salvage procedure after failed thrombolytic therapy. Balloon angioplasty is the traditional, basic technique of coronary intervention, but this is now uncommonly employed as a stand-alone treatment. A variety of percutaneous techniques can be used to remove atheroma or thrombus from coronary arteries as a prelude to angioplasty/stenting.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121908355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Osteomyelitis","authors":"M. McNally, A. Berendt","doi":"10.1093/med/9780198746690.003.0468","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0468","url":null,"abstract":"Bacteria can penetrate bone from a contiguous focus of infection (e.g. a diabetic foot ulcer or local injury) or by haematogenous spread. Osteomyelitis is most commonly caused by Staphylococcus aureus, β-haemolytic streptococci, and—in some situations—aerobic Gram-negative rods. An acute inflammatory response causes oedema within bone and soft tissue, and thrombosis in vessels that can result in bone infarction. Pus may form within cancellous bone and beneath the periosteum, stripping it from the bone and leading to extensive necrosis that sometimes involves an entire bone. The process may become chronic and relapsing. Definitive diagnosis can only be confirmed with culture of bacteria from representative bone samples, supported by histological evidence of inflammation. This cannot be achieved in all cases and diagnosis is commonly made on the basis of clinical features and imaging. MRI is the standard and best method.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116815290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Immune disorders of the gastrointestinal tract","authors":"J. Bhattacharyya, A. Kaser","doi":"10.1093/med/9780198746690.003.0292","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0292","url":null,"abstract":"Immune homeostasis in the gut is the result of a delicate balance between peaceful coexistence with commensal microbiota, immunomodulatory effects of dietary antigens, and appropriate responses to pathogens. Immune disorders of the gut arise when defects in the integrity of these components lead to a dysregulated immune response to the commensal environment. Primary immunodeficiency syndromes can present with intestinal inflammation but are commonly characterized by an increased susceptibility to infections in childhood. Secondary immunodeficiency can occur in a protein-losing enteropathy where loss of immunoglobulins and lymphocytes increase susceptibility to infections, or as a result of metabolic diseases (e.g. diabetes or liver cirrhosis), infections (e.g. HIV), or drugs (e.g. chemotherapy). Immunosuppressive medication can not only lead to secondary immunodeficiency but in the context of neutropenia, cytotoxic gastrointestinal mucosal injury can lead to neutropenic typhlitis. Graft-versus-host disease arises from host antigen-presenting cells engaging with donor T cells and triggering an inflammatory cascade. Immunotherapy with checkpoint inhibitors can have significant gastrointestinal immune-related adverse effects, most notably enterocolitis. Autoimmune diseases can impact gastrointestinal function. Autoimmune dysautonomia can result in gastrointestinal-specific dysmotility and systemic IgG4-related disease can lead to autoimmune pancreatitis. Systemic autoimmune diseases can have gastrointestinal manifestations related to the primary autoimmune process or as an adverse effect of treatment. Hypersensitivity reactions to dietary antigens (e.g. peanuts) result in food allergies and can be either IgE or non-IgE mediated. Food intolerance which is not immunologically mediated is the result of pharmacological (e.g. monosodium glutamate), enzyme-related (e.g. lactose intolerance), or noncoeliac gluten sensitivity. Eosinophilic gastrointestinal tract disorders are often associated with a food allergen: treatment is with steroids and avoidance of the allergen.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124001084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structure and function of the kidney","authors":"D. G. Shirley, R. Unwin","doi":"10.1093/med/9780198746690.003.0472","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0472","url":null,"abstract":"The kidneys are the archetypal organs of homeostasis. Their primary function is filtration and segregation. Through these processes they rebalance the continual electrolyte and chemical disturbances that derive from physiological and pathological metabolic processes. Electrolytes, hydrogen (H+) ions from metabolic acids, amino acids, fatty acids, plasma proteins, immunoglobulins, and metabolic products are either retained, reabsorbed, and recycled; or they are filtered, secreted, concentrated, and excreted. These processes convert approximately 120 ml/min of primary glomerular filtrate into 1 ml/min of urine. In addition, the kidneys play crucial roles in bone mineralization, the maintenance of cardiovascular tone, systemic blood pressure, and bone marrow synthetic function via their contribution to vitamin D production, the renin–angiotensin system, and erythropoiesis.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124067755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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