摘要:

Proposed pathophysiologic mechanisms relating gastroesophageal reflux disease to cigarette smoking are reviewed. Acute experiments have shown that smokers have chronically diminished lower esophageal sphincter (LES) pressure and that periods of smoking are associated with an increased rate of reflux events. Reflux occurred primarily by the ‘abdominal strain mechanism’ rather than by transient LES relaxation. Smoking also caused chronically diminished salivary function that results in prolonged acid clearance time. Thus, smoking potentially increases esophageal acid exposure, both by increases in the number of reflux events, and a prolongation of the esophageal acid clearance t

ISSN:0257-2753    

DOI:10.1159/000171345

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Clues from patient and experimental animal studies suggest that events occurring early in the pathogenesis of Crohn’s disease are related to an inability of the immune system to eradicate one or a number of luminal antigens resulting in persistent T cell and macrophage activation. Whether the primary abnormality rests with the nature of the luminal antigen, disturbances of antigen uptake by the mucosa, antigen handling by macrophages, or macrophage-T cell interactions remains unresolved. Given the heterogeneity of clinical presentations and experimental data, Crohn’s disease may be a group of disorders associated with a number of primary defe

ISSN:0257-2753    

DOI:10.1159/000171346

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The nine different antimitochondrial antibody specificities found in non-hepatic and hepatic disorders are described. Anti-M1 and anti-M7 antibodies are associated with infectious disorders such as syphilis or myocarditis. Anti-M3 and anti-M6 have been found in the course of a drug allergic disease due to Venocuran and iproniazid, and anti-M5 antibodies seem to occur occasionally in some forms of ANA-positive and ANA-negative collagen disorders. The M1- and M7-antigens are biochemically defined as cardiolipin and sarcosine dehydrogenase, respectively. Anti-M2, anti-M4, anti-M8, anti-M9 are associated with primary biliary cirrhosis (PBC). M2 was identified as α-ketoacid-dehydrogenase complex of the inner mitochondrial membrane, anti-M4 as sulfite oxidase, an enzyme of the mitochondrial intermembrane space, and anti-M9 as glycogen phosphorylase, a cytoplasmic enzyme. M8 copurifies with outer mitochondrial membranes derived from pig kidney. Anti-M9 can occur in the absence of anti-M2 while anti-M4 and anti-M8 are always associated with anti-M2. A progressive course of PBC can be predicted with high probability even at early stages of the disease when complement fixing antibodies against M2, M4 and/or M8 are present in patients’ sera. In contrast, the presence of anti-M2/M9 antibodies heralds a benign course. The etiopathogenesis of PBC is still unknown. In PBC contact persons a strong stimulation of naturally occurring mitochondrial antibodies (NOMA) has been observed which was in contrast to the lack of this antibody type in PBC patients. Considering the generally accepted role of those antibodies in protecting individuals from infections, the failure of NOMA production may be a predisposing factor to acquire PBC more easi

ISSN:0257-2753    

DOI:10.1159/000171347

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Giardia lamblia are protozoan parasites which cause human intestinal disease. The life cycle has a multiplying intraduodenal trophozoite and an excreted cyst. Infection occurs after cyst ingestion from faecally contaminated water or by direct faecal-oral transmission in situations of poor sanitary standards, but the zoonotic nature of giardiasis is debated. The pathophysiology may arise from enzyme or active transport deficiencies, synergy with intestinal bacteria or an immunopathological process. Diagnosis is made by microscopic identification of cysts or trophozoites in small bowel samples or faeces. Symptoms are acute with diarrhoea (without blood), abdominal cramps, bloating and flatulence. The treatment of choice is either metronidazole or tinidazole. No vaccine or drug prophylaxis exists, and measures to avoid cyst ingestion should be undertaken.

ISSN:0257-2753    

DOI:10.1159/000171348

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Research into the role of the gastrointestinal tract in the regulation of hydration has primarily concentrated on its function in the prevention of dehydration. The role of the gut in thirst, in the absorption of fluids and the consequences of diarrhoea are of importance in this respect. The function of the gut in the prevention of overhydration is less well understood. Intake of fluid increases excretion of water by the kidney. Inhibition of arginine vasopressin secretion, activation of renal nerves or hormonal release are possible effector mechanisms in this response.

ISSN:0257-2753    

DOI:10.1159/000171349

出版商:S. Karger AG    

年代:1992

数据来源: Karger