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Biomedical subjects

E Weser

Publications and source records attributed to E Weser.

At least 37 records · Page 2Linked to original sources
PubMed1979

Nutritional aspects of malabsorption. Short gut adaptation.

Adaptation of remaining small bowel after extensive intestinal resection plays an important part in maintaining adequate nutrition. The metabolic consequences of short bowel depend upon the anatomic extent of bowel removed, the functional condition of remaining digestive organs and the degree to which adaptive changes occur. The pathophysiology of short bowel results primarily from the abnormal absorption of nutrients and selective metabolites leading to malnutrition and other organ complications. Nutrients in the lumen of the small intestine are required to stimulate the process of intestinal adaptation (mucosal hyperplasia). This stimulation may be mediated via direct mucosal absorption or metabolism of nutrients, the presence of pancreaticobiliary secretions in the intestine, trophic effects of circulating enteric hormones, or neurovascular influences. Understanding the mechanisms by which mucosal growth may be stimulated could lead to important clinical applications.

Animals↗
PubMed1978

Changes in gastric glandular cell kinetics after small bowel resection in the rat.

The proliferation of gastric mucosal cells was studied in male Sprague-Dawley rats after a 50% resection involving the proximal small intestine. Two months after the operation, resected and control animals were given either a single or four successive intraperitoneal injections of 1 muCi of [3H]thymidine per g of body weight. Animals from each group were killed 1 hr after the single injection and 3, 7, 30, and 60 days after the first multiple dose injection [3H]thymidine. The number of labeled parietal, chief, and mucous cells of the gastric glands were measured. At the 3-, 30-, and 60-day periods, the percentages of labeled parietal and chief cells were significantly increased in animals with small bowel resection when compared with corresponding controls. The percentages of labeled mucous cells of the gastric glands were also increased in animals with small bowel resection at the 3- and 7-day periods. One hour after a single injection of [3H]thymidine, the percentage of labeled gastric mucosal progenitor cells in animals with small bowel resection, although increased, was not significantly different from that in controls. It is, therefore, believed that the increases in percentage labeling of gastric glandular epithelial cells at 3, 7, 30, and 60 days could not solely be explained on the basis of an increased turnover rate of gastric progenitor cells. Rather, it might be concluded that the increase in glandular epithelial cells is accomplished, in part, by increased differentiation of gastric progenitor cells.

Animals↗
PubMed1977

Lactose malabsorption in Mexican-American adults.

Lactose malabsorption was determined in 277 Mexican-American (MA) and 142 Anglo-American (AA) adults aged 18 to 94 years old, and correlated with nutrient intake assessed from 24-hr dietary recalls, as well as with milk and dairy product consumption. Lactose malabsorption occurred in 144 of 277 (53%) MA and 21 of 142 (15%) AA. Analysis of dietary questionnaires revealed no differences between lactose absorbers and malabsorbers within each ethnic group in their consumption of protein, calories, riboflavin, vitamin A, or calcium. Vitamin A, calcium, and riboflavin intake was greater in AA than in MA subjects. Milk and dairy product consumption was the same in lactose absorbers and malabsorbers in both ethnic groups. Nearly 60% of MA malabsorbers and 24% of AA malabsorbers recognized experiencing symptoms after milk ingestion. Although group differences in milk consumption on the basis of lactose absorption status are not apparent, individual lactose malabsorbers may alter milk ingestion in response to lactose-induced symptoms. Lactose malabsorption occurs in over half of MA adults and may in some individuals present a clinically relevant problem.

Adolescent↗
PubMed1977

Effect of small bowel resection on the gastric mucosa in the rat.

Male Sprague-Dawley rats (120 to 130 gm), unoperated, sham-operated, and those with a 50% resection of the proximal small intestine, were studied after periods of 3, 6, 9, or 12 months. Differences in body weight and in the surface area, thickness, volume, and cellular content of the gastric mucosa between these three groups of animals were compared and statistically analyzed. After an initial loss in body weight, animals with small bowel resection and sham-operated animals attained weights equivalent to unoperated controls. Comparison of the groups for mucosal surface areas of the body of the stomachs showed no significant differences at the 3-, 6-, or 9-month periods. However, 12 months after surgery, the mucosal surface area of stomachs from resected animals was significantly greater than in corresponding controls. At 3, 6, and 9 months after resection, the thickness and volume of the gastric mucosa and the epithelial cell populations (parietal and nonparietal) of the gastric glands were significantly greater than in controls. However, at 12 months, there was no significant difference in any of these parameters between the controls and the experimental animals. The DNA content of the gastric mucosa was significantly greater for animals with small bowel resection than for corresponding controls at 1 and 6 months after surgery. It is concluded that hyperplasia of the gastric glands exists for at least 9 months after proximal small bowel resection in the rat. This hyperplastic response may be responsible for the previously observed (N Engl J Med 272:509-514, 1965; Surgery 65:292-297, 1969) gastric hypersecretion associated with extensive small bowel resection.

Animals↗
PubMed1977

Stimulation of mucosal growth in the rat ileum by bile and pancreatic secretions after jejunal resection.

After proximal small bowel resection, the remaining small intestine undergoes adaptive hyperplasia. The role of bile and pancreatic secretions in stimulating ileal mucosal growth after jejunectomy was studied. Male Sprague-Dawley rats were fed either standard rat chow or a liquid elemental diet, and were divided into four surgical groups: sham-operated; transplantation of the duodenal papilla (containing the bile and pancreatic ducts) into the ileum; 50% proximal small bowel resection (jejunectomy); and combined transplantation of the duodenal papilla into the ileum and 50% proximal small bowel resection. Four weeks after surgery the rats were killed and segments of ileum were assayed for total weight and mucosal weight, and for DNA and protein concentration per centimeter of segment. These measurements of mucosal mass were significantly increased in ileal segments adjacent to the transplanted duodenal papilla both in nonresected and jejunectomized rats, compared with their respective controls. Transplanting the duodenal papilla into the ileum significantly increased growth of the ileal mucosa after jejunectomy. The results indicate that bile and pancreatic secretions flowing into the ileal lumen stimulate mucosal growth and play a direct role in ileal adaptation to jejunal resection.

Adaptation, Physiological↗
PubMed1976

Lactose malabsorption in Mexican-American children.

Inability to absorb lactose due to low intestinal lactase is common in many population groups. This study is the first to compare lactose tolerance in 282 Mexican-American (MA) children and 51 Anglo-American (AA) children 2 to 14 years of age with the dietary intake of selected nutrients found in milk. A lactose tolerance test and a 24-hr dietary recall were obtained for each child. Gastrointestinal symptoms were carefully recorded for a 24-hr period following the lactose load. Overall prevalence of lactose malabsorption was 37% in MA children and 8% in AA children, and it increased with age. Number of symptoms occurring in lactose malabsorbers of both ethnic groups also increased with age. Mean protein intake exceeded Recommended Dietary Allowances at all ages for both ethnic groups. Mean consumption of vitamin A, calcium, and energy was below the Recommended Dietary Allowance for MA children. There were no differences in calories, nutrient, or milk intakes between lactose absorbers and malabsorbers, but AA children drank more milk than MA children. Fifteen percent of lactose-absorbing MA, 23% of malabsorbing MA, but no AA children reported having symptoms after drinking milk. There was a significantly greater incidence of lactose intolerance in MA as compared to AA children. This suggests that Mexican-Americans share in the high incidence of primary lactose intolerance characteristic of the majority of the orld's peoples.

Adolescent↗
PubMed1976

Epithelial cell loss in remaining intestine after small bowel resection in the rat.

It is known that after small bowel resection, mucosal hyperplasia and increased cell turnover occur in the remaining intestine, particularly the ileum. At the end of their life span, epithelial cells are extruded into the bowel lumen. Comparative estimates of this cell loss may be obtained by collecting the DNA from a perfused gut segment. Male Sprague-Dawley rats underwent resection of 50 cm of proximal or distal small intestine or sham operation. One and six months after surgery, 50 cm of the remaining proximal or distal remnant were perfused with saline in vivo and the perfusate DNA was assayed. The DNA recovered from the perfusate of the distal remnant was at least twice as much as that from sham control segments. This was associated with comparable increases in mucosal weight, DNA, and protein concentration per centimeter of distal remnant. No significant changes were found in perfusate DNA recovered from proximal remnants. This correlated with minimal, if any, changes in mucosal weight, DNA, or protein concentration per centimeter of these remnants. Increased desquamation of epithelial cells may reflect the hyperplasia of intestinal mucosa after bowel resection. Recovery of intraluminal DNA may prove useful as an index of intestinal adaptation.

Animals↗
PubMed1975

Comparative nutritional analysis of chemically defined diets.

Low residue, chemically defined diets containing all essential nutrients in a readily assimilated form, require minimal digestion and are almost entirely absorbed in the upper gastrointestinal tract. Within the past decade, these diets have been reported to provide nutritional support in a variety of clinical situations. The chemically defined diets presently available commercially differ in several respects. In order to provide optimal nutritional care utilizing chemically defined diets, the physician should compare the diet formulas and make the most appropriate choice for each individual patient. A comparative nutritional analysis of the currently available chemically defined diets is given.

Amino Acids↗
PubMed1975

Pyrimidine biosynthetic enzymes in rat intestine after small bowel resection.

After small bowel resection in the rat, mucosal hyperplasia and an increase in nucleic acid synthesis and cell proliferation occur in remaining small intestine. Male Sprague-Dawley rate underwent resection of 50 cm of proximal or distal intestine or sham operation. One month and 6 months after surgery, aspartate transcarbamylase, dihydroorotase, and uridine kinase were assayed in whole mucosa, and in some instances, in crypt mucosa ffrom the remaining intestinal segment. In control bowel, enzyme activity was significantly greater proximal compared with distal segments. One month after proximal or distal resection, mucosal enzyme activity per cm of gut was greater in the remnant bowel compared with controls. There was no such difference at 6 months. Specific enzyme activity of whole mucosa did not increase after resection because the assay was influenced by the disproportionately large contribution of villous protein. Specific enzyme activity (including thymidine kinase) of isolated crypt mucosa was significantly increased 1 month after distal resection. In addition, [3H]thymidine uptake into DNA of crypt mucosa from proximal remnants was also significantly increased. These results indicate that after small bowel resection, the enzymes of pryimidine biosynthesis increase in remaining bowel and parallel the accelerated rate of cell proliferation.

Adaptation, Physiological↗