Search PubMed⌕ Search

Biomedical subjects

A Ayalon

Publications and source records attributed to A Ayalon.

At least 73 records · Page 4Linked to original sources
PubMed1982

Removal of circulating gastrin and cholecystokinin into the lumen of the small intestine.

This study was undertaken to investigate the mechanism by which the small intestine removes circulating gastrin and cholecystokinin (CCK). A 100-cm (acute study, 10 dogs) or a 50-cm (chronic study, 5 dogs) segment of midjejunum was excluded in all 15 dogs. The excluded loop was perfused with 0.1 M phosphate buffer (pH 7.4), which was constantly recirculated by a peristaltic pump. It the acute control study (5 dogs), gastrin concentrations in the intestinal perfusate were increased gradually to a level of 320 +/- 49 pg/ml at 90 min (i.e., 7.6 +/- 0.9 times higher than serum gastrin levels). In the antrectomy group (5 dogs), perfusate gastrin concentrations were greatly decreased after antrectomy, in consonance with the decrease in serum gastrin concentrations. In the chronic study (5 dogs), perfusate gastrin concentrations were significantly increased after food stimulation, in consonance with the increase in serum gastrin concentrations. CCK was also released into the bowel lumen in considerable amounts basally and after endogenous release. Although one cannot exclude the possibility that a considerable amount of gastrin or CCK in the lumen may originate from the bowel segment, this study shows that the small bowel removes gastrin and CCK from the circulation by their secretion into the bowel lumen. Loss of this mechanism might partially explain the rise in gastrin levels that is observed in some patients after extensive small bowel resections.

Animals↗
PubMed1982

Release of antral gastrin in response to an intestinal meal in dogs.

This study was designed to determine whether gastrin is released by the antrum in response to an intestinal meal in dogs. Two groups of anesthetized dogs were prepared with innervated antral pouches. The antrum and duodenum were separated by complete division at the pylorus to prevent duodenoantral reflux. The duodenum and proximal jejunum were perfused with 10% liver extract at 200 ml/hr. In one group of six dogs a significant elevation of antral vein gastrin levels was observed after 45 minutes. Gastrin levels in portal and peripheral blood were not significantly elevated. In another group of eight dogs, in which antral veins were not cannulated, a significant rise in peripheral gastrin concentration was noted after 60 minutes. We conclude that gastrin is released by the antrum during the intestinal phase of gastric acid secretion; significantly increased levels of gastrin are detected in both antral and peripheral venous blood. Duodenoantral reflux, as a possible cause of this release, is ruled out by complete surgical separation between duodenum and antrum.

Animals↗
PubMed1981

Does luminal gastrin stimulate gastric acid secretion?

The effects of pentagastrin on acid secretion, short circuit current, electrical conductance and potential difference were determined in isolated bullfrog fundic mucosa. Biologically active luminal pentagastrin had no effect on gastric mucosa, even at a concentration 100 times higher than that necessary for stimulation of the mucosa from the serosal side. It is concluded that luminal gastrin does not appear to have a physiologic role in gastric secretory processes.

Animals↗
PubMed1980

Suppression of gastric acid secretion by furosemide in isolated gastric mucosa of guinea pig.

The effect of furosemide on acid secretion and Cl- transport was studied in isolated fundic mucosa of the guinea pig. Furosemide (10(-3) M), applied to the serosal side produced an immediate effect on the short-circuit current (Isc), lowering it by 47 +/- 2%. Potential difference decreased by 29 +/- 3%, electrical conductance by 18 +/- 4%, acid secretion by 38 +/- 1%, and net flux of Cl- from serosal-to-mucosal side by 37%. Application of the drug to the mucosal side produced similar effects on acid secretion and on the electrical parameters. It is suggested that furosemide blocks the entrance of Cl-, by the Na+--Cl- cotransport mechanism, through the basolateral membrane of the secreting cell. The consequent reduction in electrogenic Cl- transport would cause Isc and acid secretion to decrease. A reduction of Cl- conductance of the apical membrane, upon mucosal application of the drug, would cause similar effects on acid secretion and Cl- transport.

Animals↗
PubMed1980

Horner's syndrome: a complication of internal jugular vein cannulation.

Percutaneous internal jugular vein cannulation has become an accepted method for placement of central venous catheters. A variety of complications connected with this procedure have been noted, but direct injury to the sympathetic trunk causing Horner's syndrome is extremely rare. A description of repeated attempts of percutaneous cannulation of the right internal jugular vein which led to the occurrence of Horner's syndrome is given.

Adult↗
PubMed1980

Gastric outlet obstruction after parietal cell vagotomy with omentopexy for perforated duodenal ulcer.

A 38-year-old man developed pyloric stenosis one year after parietal cell vagotomy with omentopexy had been performed for perforated duodenal ulcer. Gastric outlet obstruction frequently occurs after treatment of perforated ulcer by omentopexy alone, and may also occur after parietal cell vagotomy with omentopexy. The usefulness of this combined procedure as a definitive treatment for perforated duodenal ulcer remains in question.

Adult↗
PubMed1979

Precipitation membrane effects in biologic membranes: the role of calcium.

Biologic membranes display rectification of electrical current, as well as other properties, in many respects similar to precipitation membranes. The experiments reported here, performed in frog skin, show that these characteristics are dependent upon the presence of calcium. Upon elimination of calcium from the bathing solution, the property of electrical rectification is lost, the current-voltage relation assuming a linear form. Readministration of calcium brings about complete recovery of the rectification pattern. This behavior is analogous to chemical deconditioning of precipitation membranes. Our findings support the assumption that the binding of calcium in biologic membranes produces electrical effects characteristic of precipitation membranes.

Animals↗
PubMed1979

Ureterocele--a familial congenital anomaly.

Nonidentical twins with ectopic ureteroceles, and duplication of the urinary collecting system in two more members of the same family are described. This incidence may indicate that inborn anomalies of the urinary tract may have a genetic background.

Diseases in Twins↗
PubMed1979

Percutaneous cannulation of the internal jugular vein in infants and children.

A technique for percutaneous catheterization of the internal jugular vein in infants and children was used since January 1975 in 206 patients ranging in age from a few hours to 12 years old. The series included 31 premature infants weighing less than 2,500 grams and 107 babies weighing less than 4,000 grams. Five attempts at cannulation failed. Each catheterization procedure required an average of 1.8 needle insertions before the vein was entered. In 129 patients, the first attempt was successful. Sixteen complications related to the procedure occurred early in our experience, seven of which were life threatening. One death was directly ascribed to the actual insertion of the catheter and mediastinal extravasation of infusion material. Most of the early complications probably could have been injected through the catheter immediately after cannulation, in addition to aspirating the blood and lowering the infusion bottle. The 22 late complications were related to infection; one infant died because of catheter sepsis. To minimize septic complications, an arbitrary limit of seven days was set, after which the catheter was replaced. Cannulation of the internal jugular vein in infants and children should be regarded as a serious surgical procedure to be performed by a trained team and only when properly indicated.

Bacterial Infections↗
PubMed1979

Acute appendicitis in a premature baby.

Acute appendicitis with perforation in a premature baby, weighing 1 050 g, is described. Initially the infant did well after surgery, but succumbed to sepsis, as a result of hyperalimentation, eleven days later. This is the smallest infant suffering from appendicitis reported in the English literature.

Acute Disease↗