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Biomedical subjects

G Willems

Publications and source records attributed to G Willems.

At least 145 records · Page 8Linked to original sources
PubMed1981

The effect of a liquid elemental diet on cell proliferation in the colon of rats.

A liquid elemental diet (Vivonex) was given to rats for 6 days while control animals received a normal diet. At the end of the experiment each animal received one intraperitoneal injection of tritiated thymidine at 8 a.m. Animals from each group were killed hourly during the first 24 h after the injection and the proliferative activity was studied by autoradiography of the mucosa of the colon using the labeled mitoses-wave method. The epithelial cell proliferation was significantly decreased in the colon of the Vivonex-fed animals.

Animals↗
PubMed1981

Effect of a lithogenic diet on cell proliferation in the murine gallbladder epithelium.

A cholesterol-cholic acid lithogenic diet was administered to mice for periods from 2 days to 12 weeks. Intraperitoneal injections of tritiated thymidine and autoradiographs were used for the estimation of the proliferative parameters in the gallbladder epithelium. The total DNA content of the gallbladder was determined. Significantly higher labeling (p less than 0.01) and mitotic (p less than 0.01) indices were observed from the 2nd day and the total DNA content of the gallbladder was increased (p less than 0.01) from the 2nd week of the diet. Increased proliferative activity was followed by hyperplasia of the gallbladder epithelium. A significant dilatation of the gallbladders was also noted from the 2nd day of the diet (p less than 0.01). Gallstones appeared after at least 4 weeks. Our results indicate that gallstone formation is preceded by a higher proliferative activity in the gallbladder mucosa. Distension of the gallbladder could be one of the factors explaining this phenomenon in mice, but the influence of intraluminal modifications in the bile salt composition cannot be excluded.

Animals↗
PubMed1980

The effect of caerulein on epithelial growth in the mouse gall bladder.

Caerulein, a synthetic decapeptide, was injected into mice in order to study its effect on DNA-synthesis activity in the gall bladder epithelium. Histoautoradiography after the injection of labeled thymidine was used. Higher labeling indices were observed at 8, 12, 12 and 24 h after caerulein injection. These data indicate that caerulein, apart from its cholecystokinetic effects, exerts a trophic effect on the gall bladder mucosa.

Animals↗
PubMed1980

Antral gastrin cell hyperplasia in patients with peptic ulcer.

The total number of gastrin (G) cells in the stomach was determined by using a histologic counting method and planimetry in ulcerous and nonulcerous patients. The preoperative basal and postprandial serum gastrin values and the gastrin cell mass in the gastrectomy specimen could be compared in 16 surgical patients. There was a significant correlation between the integrated gastrin response to feeding and the total gastrin cell number in the stomach. No correlation was found between the basal serum gastrin level and the total gastrin cell count. A total gastrin cell number higher than 50 million was found in the stomach of three duodenal ulcer patients with preoperative postprandial hypergastrinemia as well as in one patient with normal serum gastrin values. Gastrin cell counts between 6 and 42 million were found in control stomachs and in patients with gastric ulcer. Preoperative feeding tests could be useful to select patients with an elevated antral G cell number.

Cell Count↗
PubMed1980

[Effect of foreign bodies on the gallbladder mucosa of guinea pigs].

Foreign bodies were introduced in the gallbladder of the guinea pig in order to study their effect on the cell proliferative parameters in the gallbladder mucosa. In vitro labeling with radioactive thymidine and autoradiographies were used. Our data show that the surgical manipulation of the control gallbladders had no effect on the mucosa. The introduction of polystyrene bodies was accompanied by a significant increase in DNA synthesis activity in the gallbladder epithelium.

Animals↗
PubMed1980

Induction of antral gastrin cell proliferation by refeeding of rats after fasting.

The proliferation of antral gastrin cells after fasting and refeeding of rats was studied by using a quantitative histologic method for determining the gastrin cell number and a radioautographic technique after injections of tritiated thymidine for recognizing and quantitating the newly formed gastrin cells. The total number of gastrin cells decreased 68% (P less than 0.01) after a 4-day fasting period, whereas refeeding of rats during 6 days after a 4-day fasting period resulted in a 79% (P less than 0.01) increase of the gastrin cell mass. The labeling index of gastrin cells after six daily injections of tritiated thymidine given during this period of refeeding was significantly (P less than 0.01) increased when compared with this value in control animals. The observed intensity of the proliferative response during refeeding was compatible with the increase in gastrin cell number observed during refeeding. These observations indicate that a new population of gastrin cells is formed in the antral glands when rats are refed after fasting.

Animals↗
PubMed1979

Cell proliferation in the human gallbladder epithelium: effect of distension.

DNA synthesis activity in the epithelium of the human gallbladder was studied through in vitro labelling of mucosal specimens with 3H-thymidine and autoradiography. The specimens were taken at the time of a surgical operation. Eight 'normal' gallbladders and six distended gallbladders from patients with carcinomatous obstruction of the common bile duct were examined. Proliferative activity was very low in the normal and significantly higher in the distended gallbladders.

Adolescent↗
PubMed1978

Antral gastrin cell proliferation after vagotomy in rats.

The total number of antral gastrin cells, the antral surface area and the serum gastrin concentration were determined in two groups of rats. The animals had been submitted at random either to vagotomy and pyloroplasty or to pyloroplasty alone 3 weeks before. The indirect immunoperoxidase reaction and a direct quantitative histological method were used to count the gastrin cells. Radioimmunoassay was used to estimate the serum gastrin concentration. The total number of gastrin cells in the stomach was 52% (p less than 0.01) more elevated in the vagotomized animals. Both antral mucosal surface and calculated concentration of gastrin cells per square millimeter of mucosa were significantly higher (0.01 less than p less than 0.05) in this group of animals. The serum gastrin values were significantly (p less than 0.01) more elevated after vagotomy. These observations indicate that vagotomy may induce an antral gastrin cell hyperplasia which could explain in part the hypergastrinemia observed after this surgical procedure.

Animals↗
PubMed1978

Estimation of the antral and duodenal gastrin cell population removed by gastrectomy from patients with peptic ulcer.

The total number of gastric and duodenal gastrin cells was determined in the gastrectomy specimens from eight patients with peptic ulcer. Planimetry was used to determine the antral and duodenal surface. The immunoperoxydase method with specific antigastrin antibodies was used for staining gastrin cells, and the mean concentration of nucleated gastrin cells per square millimeter of antral and duodenal surface was determined by light microscopy. The mean number of duodenal gastrin cells in the resected duodenum was 4.8 per cent of the total gastric gastrin cell mass. The concentration of gastrin cells in the antrum was quite variable from one mucosal site to another. The degree of extension of the antral gastritic areas was a major factor influencing the mean concentration value. The total number of gastrin cells in the stomach varied from approximately 7 to 74 million cells. Our data indicate that hyperplasia of gastrin cells cannot be demonstrated by studies performed in small specimens taken for biopsy.

Cell Count↗
PubMed1977

Endogenous hypergastrinemia and cell proliferation in the fundic mucosa in dogs.

Endogenous hypergastrinemia (P less than 0.01) was produced in 4 dogs with a Heidenhain pouch through surgical exclusion of the pyloric antrum. This was followed by acid hypersecrection and increased DNA synthesis and mitotic activity (P less than 0.01) in the mucosa of the Heidenhain pouch. The acid hypersecretion induced by histamine in beeswax in 4 other dogs did not increase the proliferative parameters in the pouch mucosa of the latter. A positive correlation (r = 0.84, P less than 0.01) was found between the serum gastrin levels and the DNA synthesis index values measured in the 4 animals before antral exclusion, after antral exclusion, and after antrectomy. These data support the hypothesis that the trophic effect of gastrin on the fundic mucosa can be elicited by physiological doses of endogenous hormone.

Animals↗
PubMed1977

Opposite effects of gastrin on cell proliferation in the antrum and other parts of the upper-gastrointestinal tract in the rat.

The effect of gastrin on DNA synthesis and mitotic activity in the mucosa of the upper-gastrointestinal tract was explored in unanesthetized rats with a gastric fistula. Animals were killed at 4-hr intervals, after starting a 3-hr intravenous infusion with the lowest dose of gastrin provoking a maximal acid output. Tritiated thymidine was injected 1 hr before killing. Autoradiography was used, and labeling and mitotic indices were estimated in the fundic, antral, duodenal, and jejunal mucosa. The proliferative activity in the fundic, duodenal, and jejunal glands was significantly increased 16 hr after the administration of gastrin. In the antral glands, however, a significant decrease in both labeling and mitotic indices was observed. Rhythmic variations in proliferative activity were observed in the antral, duodenal, and jejunal mucosa in control animals. They were different from those in the gastrin-treated animals. Our data confirm the trophic action of gastrin in the fundic, duodenal, and jejunal mucosa. They also indicate an inhibitory effect of this hormone on cell proliferation in the antral mucosa.

Animals↗