Clinical science and molecular medicine最新文献

1. The administration of a single oral dose of 2, 3, 4 or 5 g of ethanol/kg (43.5, 65.2, 87.0 or 108.7 mmol/kg respectively) to rats increases the rate of oxygen consumption by liver slices from animals killed 24--48 h later. 2. The increase in the rate of hepatic respiration can be blocked by incubation in a medium containing ouabain, an inhibitor of the sodium pump, or in a calcium-free medium. 3. The enhancement of oxygen uptake caused by a single dose of ethanol can be abolished by adrenalectomy or by prior administration of the alpha-adrenergic blocking agent phentolamine, and is markedly less in thyroidectomized animals. 4. It is suggested that the effect which is elicited by acute ethanol administration on respiration by liver slices is mediated by adrenaline and by throid hormones, both of which appear to exert a calorigenic effect by activation of the sodium pump. The results are discussed in relation to the changes in liver oxidative capacity induced by chronic alcohol ingestion.

1. The metabolism of oxygen by phagocytosing neutrophils was traced by using 15O2. 2. The isotope did not exchange with the incubation medium or cells to an appreciable extent and unmetabolized oxygen was readily eluted by gassing the cell suspension. 3. The polarographic measurements of oxygen consumption closely paralleled the recovery of metabolized 15O2. 4. Almost all the metabolized 15O2 was converted into water, both in the presence and absence of KCN, supporting the concept that the oxygen consumed by neutrophils is converted into H2O2. It is unlikely that an appreciable proportion of this oxygen is incorporated into the organic composition of the cell or of the ingested micro-organism.

1. Arterial concentration and arterial-venous differences of glutamine across the kidney, forearm, hepato-splanchnic bed and brain were measured in patients with chronic renal insufficiency and in patients with normally functioning kidneys before and during chronic ammonium chloride acidosis. 2. In chronic renal insufficiency and in chronic metabolic acidosis there is a rise in glutamine release from the muscles and a suppression of glutamine uptake by the hepato-splanchnic bed and the brain. 3. In chronic renal insufficiency arterial glutamine concentrations is significantly increased in comparison with subjects with normal renal function and either normal acid-base balance or chronic metabolic acidosis. 4. In patients with chronic renal insufficiency the kidney extracts negligible amounts of glutamine, which cannot account for the renal ammonia production measured in the same patients.

1. The effects of phenol and phenyl glucuronide on the responses of normal rat brain adenyl cyclase to noradrenaline and dopamine have been investigated. Neurotransmitter responses have also been examined in brains from uraemic and normal rats. 2. A depressive effect of phenol on the adenosine 3' :5' -cyclic monophosphate response of the neostriatum to dopamine was shown to be completely abolished if the toxin was present in the conjugated form; the response of the cortex to noradrenaline was stimulated by the presence of phenyl glucuronide, even though the unconjugated form had no effect. 3. The uraemic state in the rat also resulted in a depression of the neostriatum response to dopamine, yet an enhancement of the cortical response to noradrenaline. 4. The action of phenols of the brain is relevant to hepatic and uraemic coma.

1. Jejunal biopsies from five patients with non-responsive coeliac disease have been subjected to analytical subcellular fractionation and enzymic microassay in order to compare the organelle pathology of this group with untreated but glutensensitive patients. 2. Compared with the gluten-sensitive group these non-responsive patients showed marked reduction of the endoplasmic reticulum enzymes, normal activities of lysosomal enzymes and slightly less severely reduced brush border activities. 3. It is suggested that the present biochemical studies in combination with previous clinical reports and measurements of DNA and protein synthesis by cultured mucosal biopsies delineate non-responsive coeliac disease as a distinct entity. 4. The patients were treated with oral prednisolone (20 mg daily) for between 5 and 9 weeks and the properties of the jejunal biopsies restudied. 5. Although morphologically there was only a partial restoration of the villus architecture the enzymic alterations and organelle abnormalities returned essentially to normal values.