ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

An earlier hypothesis based on the results of pancreatic studies in cystic fibrosis (CF) patients without steatorrhoea suggesting that the basic defect was related to an abnormality in control of electrolyte movement, particularly the bicarbonate ion, and water in exocrine secretory tissue is reviewed in light of recent advances in knowledge of secretory mechanisms. Evidence for defective bicarbonate–chloride exchange in a variety of CF exocrine tissues other than the pancreas is cited. Recent recognition of the close relationship between bicarbonate and mucus secretion and their stimulation by prostaglandin E2is discussed. Consideration is given to the possibility of altered metabolism of PGE2because of abnormal handling of essential fatty acids in CF, and an attempt is made to relate such a defect to the recent confirmation of oligosaccharide side chain differences such as an increased fucose–sialic acid ratio in CF gastrointestinal mucus and other glycoproteins. It is suggested that membrane permeability to chloride, bicarbonate–chloride exchange, and movement of water through extra-and intracellular exocrine tissues depends on modifications of the carbohydrate structure of glycoproteins during secretion and that these changes are stimulated by co-ordination of cell messengers PGE2, calcium, and cyclic AMP. Disturbed PGE2metabolism in CF could inhibit these changes rendering resulting secretions dry, concentrated, and readily able to block ducts or tubes.

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A 1-h basal collection of gastric secretions was taken from 14 healthy full-term infants (group I) and 10 premature infants (group II). Simultaneously, acid and intrinsic factor (IF) secretion was measured. In an additional group of 19 full-term infants (group III), 16 had IF detectable in their gastric secretions immediately at birth. Volumes of gastric juice (ml/kg/h) and IF secretion (ng/ kg/h) were similar for group I and group II infants. Acid secretion (mEq/kg/h) was significantly less in group II (p < 0.01). There was a linear correlation between acid secretion (mEq/kg/h) and IF secretion (ng/kg/h) for group I (r = 0.85, p < 0.001). There was no correlation between the values for the premature infants in group II. The study documents that the parietal cell of the premature infant has the same capacity to secrete IF as the cell of the more mature infant. It also demonstrates the presence at birth of IF in gastric secretions, which suggestsin uterosecretion and independence from enteral feeding for stimulation.

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Particles of meconium sedimenting at 105,000gcontain sucrase and various brush border peptidase activities. Oligoaminopeptidase, dipeptidylaminopeptidase, and sucrase solubilized by papain from meconium particles of preterm newborns or from brush border of human fetuses during the 4th month of gestation were compared with the same enzymes prepared from adult jejunal and ileal brush border. The following are characteristics of fetal intestinal brush border enzymes: (a) a faster anodal electrophoretic mobility in polyacrylamide and in agar gel; (b) the same specific activity, as measured by quantitative crossed immunoelectrophoresis utilizing an antiserum against adult brush border membranes; (c) complete fusion of the immunoprecipitation lines with the adult enzymes by using the same antiserum; and (d) a different binding pattern toHelix pomatialectin and lentil lectin. The results suggest that the charge difference between adult and fetal human brush border enzymes, which causes the difference in the gel electrophoretic mobility, is most probably due, at least in part, to differences in carbohydrate composition of these glycoproteins. Extensive neuraminidase digestion causes no or only minor changes of the electrophoretic mobility of the meconial enzymes. The difference between adult and meconial enzymes is therefore apparently not, or not only, due to different sialic acid content. These results suggest that many intestinal brush border enzymes in fetal life and at birth are in forms structurally different from those in adult life.

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

We report results on determinations of small intestinal brush-border enzyme activities in 22 children (aged 11 months to 14 years) with giardiasis. In particular, activities of disaccharidases (lactase, sucrase, maltase) and of alkaline phosphatase were investigated. Forty-one percent of the patients, irrespective of age, had a demonstrable depression of disaccharidase activities, usually in a combination involving two or more enzymes. A depression of intestinal alkaline phosphatase activity was present in 33% of patients, and only in those who demonstrated disaccharidase deficiencies. Mild villus atrophy was present in two mucosal specimens, whereas all others showed normal villus morphology by light microscopy. The results obtained in this study suggest that giardiasis in otherwise healthy children does not cause marked structural damage to the small bowel mucosa, as seen by the light microscope. However, some form of damage to the brush border does occur frequently, as evidenced by a depression of brush-border enzymes. This damage most likely contributes to the diarrhea and also to the carbohydrate intolerance in these patients.

ISSN:0277-2116    

出版商:OVID    

年代:1984

数据来源: OVID