Oxford Textbook of Medicine最新文献

{"title":"Radiology of the gastrointestinal tract","authors":"F. Moloney, M. Maher","doi":"10.1148/101.3.530","DOIUrl":"https://doi.org/10.1148/101.3.530","url":null,"abstract":"The widespread introduction of endoscopic techniques has reduced the need for radiological examination of the intestinal tract and has almost completely rendered imaging of the stomach obsolete. There remains, however, a substantial role for radiological imaging in the investigation of the small and large bowel in the diagnosis of abdominal and gastrointestinal disease. The small intestine may be examined by a number of radiological techniques, including plain films, barium contrast studies, ultrasonography, CT, MRI, and nuclear medicine. Barium studies (follow-through or small-bowel enema) can provide good morphological detail of the mucosal surface of the bowel; cross-sectional imaging (usually CT or MRI) is required for disease in the wall of the bowel or outside it. CT is increasingly used as the primary investigation in suspected bowel obstruction. Nuclear medicine studies have a major role in the examination of the small bowel for the presence of inflammatory conditions, and for demonstration of potential bleeding sources. Colonoscopy has revolutionized imaging approaches to the colon because of its proven diagnostic efficacy and the added facility for biopsy of diffuse mucosal pathology and focal mucosal lesions, but is associated with a small risk of perforation. The use of barium enema continues to decline steadily. The advent of multidetector CT that allows three-dimensional reconstruction has led to a large number of new applications, including virtual colonoscopy or colonography, use of which is steadily increasing and is particularly valuable in the setting of unsuccessful or incomplete optical colonoscopy, although it is disadvantaged by inability to perform biopsy.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"46 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":"116855504","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":"Erythrocyte enzymopathies","authors":"A. Zanella, P. Bianchi","doi":"10.1093/med/9780198746690.003.0540","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0540","url":null,"abstract":"Numerous enzymes, including those of the hexose monophosphate and glycolytic pathways, are active in the red cell. They are required for the generation of ATP and the reductants NADH and NADPH. 2,3-Diphosphoglycerate, an intermediate of glucose metabolism, is a key regulator of the affinity of haemoglobin for oxygen, and accessory enzymes are also active for the synthesis of glutathione, disposal of oxygen free radicals, and for nucleotide metabolism. With the exception of heavy metal poisoning and rare cases of myelodysplasia, most red cell enzyme deficiency disorders are inherited. They may cause haematological abnormalities, (most commonly nonspherocytic haemolytic anaemias, but also rarely polycythaemia or methaemoglobinaemia, manifest with autosomal recessive or sex-linked inheritance), and may also be associated with nonhaematological disease when the defective enzyme is expressed throughout the body. Some may mirror important metabolic disorders, without producing haematological problems, making them of diagnostic value. Others are of no known clinical consequence. With rare exceptions, it is impossible to differentiate the enzymatic defects from one another by clinical or routine laboratory methods. Diagnosis depends on the combination of (1) accurate ascertainment of the family history; (2) morphological observations—these can determine whether haemolysis is present, rule out some causes of haemolysis (e.g. hereditary spherocytosis and other red blood cell membrane disorders), and diagnose pyrimidine 5′-nucleotidase deficiency (prominent red cell stippling); (3) estimation of red cell enzyme activity; and (4) molecular analysis. The most common red cell enzyme defects are glucose-6-phosphate dehydrogenase deficiency, pyruvate kinase deficiency, glucose-6-phosphate isomerase deficiency, pyrimidine 5′-nucleotidase deficiency—which may also induced by exposure to environmental lead—and triosephosphate isomerase deficiency.","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":"117276332","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 innate immune system","authors":"P. Bowness","doi":"10.1093/med/9780199204854.003.050101","DOIUrl":"https://doi.org/10.1093/med/9780199204854.003.050101","url":null,"abstract":"The innate immune system comprises evolutionarily ancient mechanisms that mediate first-line responses against microbial pathogens, and are also important in priming and execution of adaptive immune responses, and in defence against tumours. These responses, which recognize microbial non-self, damaged self, and absent self, are characterized by rapidity of action and they involve various different cell types, cell-associated receptors, and soluble factors. Previously thought to lack plasticity or memory, certain innate immune responses have recently been shown to be capable of ‘learning’ or ‘training’. Most cells of the innate immune system are derived from the myeloid precursors in the bone marrow. These include monocytes and their derivatives—macrophages and dendritic cells, blood granulocytes (neutrophils, basophils, and eosinophils), and tissue mast cells.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"22 9 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":"123240517","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":"Hereditary haemochromatosis","authors":"W. Griffiths, T. Cox","doi":"10.1093/med/9780198746690.003.0233","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0233","url":null,"abstract":"Hereditary haemochromatosis syndromes are inherited disorders whereby inappropriate absorption of iron by the small intestine leads to iron deposition in the viscera, endocrine organs, and other sites, causing structural injury and impaired function. The most common form is classical adult (HFE-related) haemochromatosis, but other forms are recognized. Extended genetic platforms are increasingly used for specific diagnosis and noninvasive methods are increasingly used to evaluate hepatic damage. The mainstay of treatment is venesection although iron chelation therapy is an emerging oral alternative. Unravelling the molecular genetics of haemochromatosis is underpinning promising new therapies for disorders of iron homeostasis. Classical adult (HFE-related) haemochromatosis: aetiology and pathogenesis—inherited as a recessive trait and due to mutations in the major histocompatibility complex class I-related HFE gene that appear to reduce liver production of hepcidin. The principal mutant allele of HFE, designated C282Y, is carried by approximately 1 in 10 individuals of European ancestry, hence around 1 in 200 are homozygotes, usually with biochemical abnormalities of iron storage that may lead to full-blown clinical haemochromatosis. Clinical features—expression of disease may range from slight abnormalities of blood parameters that reflect iron metabolism to the established clinical syndrome of cutaneous pigmentation, cardiomyopathy, endocrine failure (especially diabetes mellitus and hypogonadism), arthritis, and pigment cirrhosis. Diagnosis—usually established by demonstrating abnormalities of iron metabolism. Molecular analysis of the HFE gene, in particular for homozygosity for the C282Y allele, is confirmatory. Management and prognosis—this is directed to the removal of iron by phlebotomy until the serum ferritin concentration is reduced to within the low normal range, after which the frequency of phlebotomy is reduced. Family members—first-degree relatives should be offered screening.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"21 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":"124267809","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":"Thrombosis in pregnancy","authors":"P. Maccallum, L. Bowles","doi":"10.1093/med/9780198746690.003.0269","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0269","url":null,"abstract":"Pregnancy and the puerperium are associated with a 10-fold increase in the risk of venous thromboembolism, comprising deep vein thrombosis and pulmonary embolism, compared to the non-pregnant state. Pulmonary embolism has been the leading direct cause of maternal mortality in most of the United Kingdom’s triennial Confidential Enquiries into Maternal Deaths over the past 30 years, attesting to the importance of prevention and prompt diagnosis and treatment of venous thromboembolism during pregnancy and following delivery. The diagnosis of venous thromboembolism is challenging in pregnancy because it can be difficult to distinguish features of venous thromboembolism, such as leg swelling and breathlessness, from those of normal pregnancy, and there are no validated clinical scoring systems. All women should undergo risk assessment for venous thromboembolism in early pregnancy, at the time of hospital admission or change in clinical condition, and after delivery.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"8 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":"125505508","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":"Bartonellas excluding B. bacilliformis","authors":"E. Angelakis, D. Raoult, J. Rolain","doi":"10.1093/med/9780199204854.003.070642_update_001","DOIUrl":"https://doi.org/10.1093/med/9780199204854.003.070642_update_001","url":null,"abstract":"Bartonellae are Gram-negative bacilli or coccobacilli belonging to the α‎-2 subgroup of Proteobacteria. A given Bartonella species usually persists within a given mammalian host, with transmission between hosts by haematophagous arthropods. A single species, such as B. henselae or B. quintana, can cause acute or chronic infection, with vascular, proliferative, or suppurative features depending on the host’s immune response. Many new Bartonella species isolated from various mammals have been identified as zoonotic.\u0000 \u0000 Cat-scratch disease—caused by B. henselae and commonly associated with a cat scratch, presents with a discrete papule or vesicle typically developing at the site within a week, followed by regional lymphadenopathy, sometimes with fever and constitutional symptoms. Disseminated infection can cause neuro-retinitis and (rarely) encephalopathy.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"23 4 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":"126225038","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":"Eosinophilia","authors":"P. Weller","doi":"10.1093/med/9780198746690.003.0520","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0520","url":null,"abstract":"Eosinophilia (eosinophil count >0.45 × 109/litre) is associated with some infections, some allergic diseases, and a variety of other conditions, sometimes neoplastic. Parasitic diseases—eosinophilia is a characteristic feature of infection by multicellular helminth parasites (e.g. Strongyloides stercoralis) with diagnosis typically based on geographical/dietary history, serological tests, and examination of stool or tissues for parasite forms. Other diseases—eosinophilia can be caused by the fungal disease coccidioidomycosis, and modest eosinophilia may accompany retroviral infections such as HIV and HTLV-1. Common allergic diseases—asthma, rhinitis, and atopic dermatitis are associated with modest eosinophilia. Drug reactions—these are a frequent cause of eosinophilia, at times in reactions characterized by rashes and pyrexia. More severe reactions may also manifest with (1) pulmonary eosinophilia and lung infiltrates; (2) interstitial nephritis; (3) hepatitis; (4) myocarditis; (5) drug-induced hypersensitivity vasculitis; (6) gastroenterocolitis; and (7) DRESS syndrome. Other conditions—these include (1) eosinophilic granulomatosis with polyangiitis; (2) hyper-IgE syndromes; (3) chronic myeloid leukaemia, acute myeloid leukaemia, and lymphoma; (4) a variety of pulmonary, skin, gastrointestinal, and endocrine diseases. Hypereosinophilic syndromes are defined by (1) eosinophilia (>1.5 × 109/litre) sustained over a month, (2) lack of an identifiable cause precipitating a secondary eosinophilia, and (3) symptoms and signs of organ involvement. About 30% of patients will have either a myeloproliferative condition (chronic eosinophilic leukaemia) or hypereosinophilia mediated by clonal expansion of specific T cells producing interleukin-5 (IL-5). Treatment—patients without organ damage do not require treatment. Aside from supportive care, chronic eosinophilic leukaemia may respond to tyrosine kinase inhibitors (e.g. imatinib), and nonmyeloproliferative hypereosinophilic syndrome may respond to high-dose corticosteroids, with hydroxyurea, interferon-α‎ or anti-IL-5 monoclonal antibody used in refractory cases.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"21 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":"126032164","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":"Erythropoiesis","authors":"V. Sankaran","doi":"10.1093/med/9780198746690.003.0531","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0531","url":null,"abstract":"Erythropoiesis is a highly regulated, multistep process in which stem cells, after a series of amplification divisions, generate multipotential progenitor cells, then oligo- and finally unilineage erythroid progenitors, and then morphologically recognizable erythroid precursors and mature red cells. The ontogeny of erythropoiesis involves a series of well-coordinated events during embryonic and early fetal life. In the fetus, the main site of erythropoiesis is the liver, which initially produces mainly fetal haemoglobin (HbF, α‎2γ‎2) and a small component (10–15%) of adult haemoglobin (HbA, α‎2β‎2), with the fraction of HbA rising to about 50% at birth. After birth, the site of erythroid cell production maintained throughout life is the bone marrow, with the final adult erythroid pattern (adult Hb with <1% fetal Hb) being reached a few months after birth. Regulation of erythropoiesis—the main regulator is erythropoietin, a sialoglycoprotein that is produced by interstitial cells in the kidney in response to tissue hypoxia and exerts its effect by binding to a specific receptor on erythroid burst-forming units, erythroid colony-forming units, and proerythroblasts. Abnormal erythropoietin production—anaemia can be caused by acquired or congenital deficiency in erythropoietin production, most commonly in chronic kidney disease. Impaired tissue oxygen delivery is a common cause of erythropoietin-driven secondary erythrocytosis. Some kidney cancers increase erythropoietin production and hence cause secondary erythrocytosis. Other causes of abnormal erythroid production include (1) acquired and congenital defects in erythropoietin signalling; (2) acquired and congenital defects in the transcription factors GATA1 or EKLF; (3) acquired or congenital abnormalities in ribosome synthesis or splicing factors; and (4) factors that lead to premature red cell destruction.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"1 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":"126041415","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":"Self-harm","authors":"K. Saunders, K. Hawton","doi":"10.7748/en.16.3.6.s9","DOIUrl":"https://doi.org/10.7748/en.16.3.6.s9","url":null,"abstract":"Self-harm is one of the commonest reasons people present to hospital emergency departments and the most frequent form of self-harm is overdose. Most patients who self-harm have an emotional disturbance, commonly an adjustment or mood disorder, often in a context of situational or relationship stresses, and personality difficulties. Some have more severe psychiatric disorders. Intoxication with alcohol is common. All patients presenting with self-harm require both a medical and a psychiatric assessment. The latter should include an assessment of problems, needs and suicide risk. Children require particularly careful assessment. In assessing suicide risk, it should be noted that the medical dangerousness of the act does not necessarily reflect the intent, and that repeat self-harm greatly increases the risk of eventual suicide. Psychiatric management depends on the patient's problems and diagnosis. There is some evidence that brief psychological intervention can decrease the risk of repeat self-harm.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"1 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":"130020637","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 kidney in rheumatological disorders","authors":"L. Lightstone, H. Beckwith","doi":"10.1093/med/9780198746690.003.0493","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0493","url":null,"abstract":"Many rheumatological conditions have systemic effects. Antibody production, complement activation, and protein deposition can all result in damage to the kidney, sometimes with devastating sequelae. Systemic lupus erythematosus—lupus nephritis is clinically evident in up to 75% of patients with systemic lupus erythematosus (SLE), and endstage renal disease is seen in 5 to 10% of patients at 10 years. Proteinuria is the most common clinical presentation, closely followed by nonvisible haematuria and tubular abnormalities. Patients with active lupus nephritis often have features of active SLE. The gold standard for lupus nephritis diagnosis is a renal biopsy, with treatment related to histopathological features observed. Adjunctive immunosuppressive agents such as rituximab and tacrolimus are emerging as increasingly important lupus nephritis therapies. Systemic sclerosis is a multiorgan connective tissue disease. Most renal manifestations are clinically silent. By contrast, the scleroderma renal crisis is characterized by accelerated-phase hypertension and impaired renal function. It carries a high mortality risk. Rheumatoid arthritis can affect the kidneys in many ways, most commonly by causing amyloid A amyloidosis. This presents with proteinuria, often severe enough to cause nephrotic syndrome, with 50% progressing to endstage renal failure after 5 years (90% at 10 years). Renal vasculitis, mesangiocapillary glomerulonephritis, and mesangial IgA proliferative glomerulonephritis are also described. Gold and penicillamine (now rarely used) can cause proteinuria, sometimes with nephrotic syndrome. Renal involvement in Sjögren’s syndrome is generally mild, but up to a quarter of patients develop acute or chronic kidney disease, typically with evidence of tubular dysfunction. Glomerular abnormalities are rare and the most common histological abnormality is tubulointerstitial nephritis. Drug nephrotoxicity—conventional antirheumatics and over-the-counter nonsteroidal anti-inflammatory drugs are used exceptionally widely in the community and are nephrotoxic. Their almost ubiquitous use, especially during intercurrent illnesses, means they are frequent contributors to acute and chronic kidney damage.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"26 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":"129561592","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}