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Biomedical subjects

E Lebenthal

Publications and source records attributed to E Lebenthal.

At least 163 records · Page 9Linked to original sources
PubMed1982

Effect of fasting and refeeding on pancreatic enzymes and secretagogue responsiveness in rats.

Fasting reduced amylase and increased lipase concentrations but did not affect trypsinogen concentrations in the adult rat pancreas. Fasting also decreased the pancreatic contents of trypsinogen and amylase. A decrease in the responsiveness of dispersed pancreatic acini to carbachol was evident after 3 days of fasting but only at high concentrations of secretagogues. Acini regained their responsiveness, and enzyme concentrations returned to normal after refeeding. Serum insulin levels of fasted rats decreased to one-fourth of control levels but rose to normal 24 h after refeeding. Insulin or glucose given alone prevented the increase in lipase after fasting. Both insulin and glucose were needed to maintain the acinar response to secretagogues in fasted rats. Although cholecystokinin restored the protein and trypsinogen content in fasted rats, it did not correct the relative changes in the exocrine enzymes. There are therefore reversible changes in the exocrine pancreas after fasting. Insulin, glucose, and cholecystokinin seem to regulate these changes.

Adenosine Triphosphate↗
PubMed1982

Effect of pancreozymin and secretin on intraluminal enterokinase, trypsin, and chymotrypsin activities of cystic fibrosis and control children.

Duodenal fluids from control and cystic fibrosis (CF) patients were assayed for enterokinase (EK), trypsin and chymotrypsin activities. CF patients as a group were found to have higher basal EK activity in spite of low trypsin and chymotrypsin activities. In control patients, pancreozymin (CCK) injection led to increases in specific activities of trypsin and chymotrypsin and a decrease in EK but did not change the total EK activities. Secretin administration led to decreases in specific activities of trypsin and chymotrypsin compared to post-CCK levels. The total EK activities were greatly increased following secretin administration. Thus, secretin may have direct influence on the release of EK into the duodenum. CCK and secretin have no effect on the specific activities of trypsin, chymotrypsin and EK in CF patients. EK release in CF patients is either constitutive and therefore not affected by CCK and secretin or it has been fully induced by the low trypsin content and becomes unresponsive to further hormonal stimulation.

Adolescent↗
PubMed1982

Gastric emptying in prematures of isocaloric feedings with differing osmolalities.

The role of osmolar load in the regulation of gastric emptying time was studied in 10 healthy premature infants. Two isocaloric infant feedings of similar composition with mean osmolalities of 279 and 448 mOsm/kg were compared. Emptying was studied over 120 min by the double sampling marker dilution technique and by a single aspiration of the feeding at 30 min. Similar gastric emptying times were noted for both formulas with approximately half of the initial gastric contents remaining at 30 min. The secretory response to the two meals during the first 30 min after feeding was compared by measuring the secretions present in the stomach during that time. The mean secretory response to the feedings did not differ significantly and was less than 2.5 ml in both cases. In general, a biphasic pattern of gastric emptying with a rapid early emptying phase was noted with both feedings. This study, therefore, provides evidence that when isocaloric feedings with similar composition are used, osmolar load does not play a significant role in the regulation of gastric emptying in premature infants. This study also demonstrates that differences in osmolality do not significantly affect the secretory response to a meal in the stomach of the premature infant.

Diet↗
PubMed1982

Effect of early weaning and prolonged nursing on development of the rat pancreas.

Pancreatic development was studied in rats 17-28 days of age. Control pups, weaned naturally at 21-24 days showed a gradual increase in body weight, pancreatic weight, total DNA and protein content with age. Pups weaned at 17 days showed a transient increase in pancreatic weight and protein content only at day 22; at no time did they show a difference in either DNA content or body weight. Pups nursed up to 25 days of age had a smaller body weight, but had DNA and protein content similar to control rats. Control pups showed gradual increases in lipase and trypsinogen with a sharp increase in amylase between days 22 and 25. Pups weaned at 17 days showed a precocious increase in trypsinogen and a sharp increase in amylase between days 19-22, but an immediate decrease in lipase which eventually returned to the control level at day 28. Pups nursed beyond the weaning stage showed an increase in lipase and trypsinogen but no sharp increase in amylase. A significant increase in all pancreatic enzymes, pancreatic mass, pancreatic DNA and protein content was seen in all groups of rats irrespective of their diet. The results suggest an inherent biological program as a basic control of pancreatic ontogeny with diet playing a modifying role.

Aging↗
PubMed1982

Sulfasalazine metabolite pharmacokinetics in pediatric patients with inflammatory bowel disease: effects of disease activity, acetylator phenotype, and age.

The pharmacokinetics and protein binding of sulfapyridine (SP) and its major metabolite, acetylsulfapyridine (ACSP) were examined in 17 prepubertal children and 4 postpubertal adolescents receiving sulfasalazine (SASP) for treatment of inflammatory bowel disease (IBD). Five patients were studied in both active disease and remission. Comparisons were made with a group of 24 outpatients (9-62 years) with IBD controlled on SASP and in remission. Acetylator phenotype was calculated from plasma metabolite ratios. Slow acetylators had increased plasma concentrations of SP and ACSP + SP (P less than 0.05). Apparent SP clearance (clearance/availability) was increased in active disease (P less than 0.05) and AUCSP + ACSP and AUCSP were decreased (P less than 0.05). There were no age-related alterations in apparent SP clearance. Side effects were frequent but were unrelated to SASP dose, SP concentrations, or acetylator phenotype. Disease activity did not significantly alter the serum protein binding of SP or ACSP. The decreased SP and ACSP concentrations seen in active disease may be due to a combination of disease related alterations in either cleavage of SASP or absorption and clearance of SP.

Acetylation↗
PubMed1982

Pancreozymin and secretin enhance duodenal fluid antibody levels to cow's milk proteins.

Duodenal fluid was collected from normal volunteers before and after stimulation with pancreozymin-cholecystokinin and secretin. Protein content, proteolytic enzyme activities, and antibody activities against cow's milk proteins, alpha-casein, and beta-lactoglobulin B, were measured in the duodenal fluid. After pancreozymin-cholecystokinin stimulation, immunoglobulin A and immunoglobulin M antibody activities rose to peak levels in 5-10 min. The increase in protein content and proteolytic enzyme activities after pancreozymin-cholecystokinin stimulation paralleled the increase in antibody activity against the two cow's milk proteins. Secretin, in spite of its known dilutional effect on duodenal fluid enzyme concentration, also produced a rise in immunoglobulin M and immunoglobulin A antibody activities. Only a slight increase in immunoglobulin G antibody activity was noted after both pancreozymin-cholecystokinin and secretin. It is suggested that, pancreozymin-cholecystokinin and secretin, in addition to their well-established effects on the release of digestive enzymes, also stimulate release of specific antibodies against food proteins. Release of antibody coincident with food intake may act in preventing the inadvertent absorption of antigenic food proteins.

Adult↗
PubMed1981

Effect of leukemia and methotrexate on digestive enzymes in the jejunum of mice.

A leukemic mouse model was employed to elucidate the separate effect of leukemia and cytotoxic drugs on the jejunal mucosa and its associated digestive enzymes. The mitotic activity, depth of the crypt and villus-crypt quotient were not significantly changed in leukemic mice in comparison to normal mice. The mitotic activity and the depth of the crypt 48 h after 20 mg methotrexate (MTX)/kg were significantly reduced (p less than 0.01) in leukemic mice. Sucrase (p less than 0.001) and maltase (p less than 0.025) activities in the jejunum from leukemic mice were significantly elevated in comparison with non-leukemic controls. In both non-leukemic and leukemic mice, the dose-response curves for MTX administration revealed a significant decrease and a nadir in sucrase (p less than 0.001) and maltase (p less than 0.0025) activities at the dosage of 20 mg/kg. Thus, in the mouse model, leukemia per se does not contribute to significant diminution in small intestinal function. In the small intestine, MTX appears to be responsible for a decrease in the mitotic activity of crypt cells, depth of the crypt and diminished sucrase and maltase activities.

Alkaline Phosphatase↗
PubMed1981

Effect of intrauterine growth retardation on the activities of fetal intestinal enzymes in rats.

The activities of maltase, lactase, alkaline phosphatase and enterokinase were followed in the small intestine of rats during prenatal development. These enzymes were detectable only after the 17th day of gestation. Furthermore, each enzyme exhibited a different pattern of prenatal presence. Maltase activity appeared first (day 18), followed by lactase and alkaline phosphatase (day 19) and then enterokinase (day 20). Except for enterokinase, all of the enzymes attained a level of activity close to the newborn levels at the final day of gestation. Induced intrauterine growth retardation during the 3rd trimester led to a decrease in intestinal weight proportional to the reduction of body weight. These decrease in size of the small intestine was caused by a reduction in cell number rather than cell size. Induced intrauterine growth retardation also resulted in a selective reduction in the specific activities of lactase and alkaline phosphatase, but not of enterokinase and maltase. These results suggest that reduction in maternofetal blood flow in the 3rd trimester of gestation will cause a selective decrease in some brush border enzymes (lactase and alkaline phosphatase) but does not effect others (maltase and enterokinase).

Alkaline Phosphatase↗
PubMed1981

The development of pancreatic function in premature infants after milk-based and soy-based formulas.

Thirty-one premature infants who required nasojejunal feeding were evaluated for pancreatic exocrine function before and after feeding of milk-based or soy-based formulas for 30 days. The two groups were well matched for age and birth weight (about 1.5 kg). At birth, all infants had high basal secretion of trypsin and chymotrypsin, but low lipase and no amylase activity. Additionally, there was no response to pancreozymin (CCK). After 30 days of feeding with either soy or milk-based formulas, both groups showed a similar increase in body weight (to 1.8 kg) and basal secretion of trypsin, chymotrypsin, and lipase and failure to secrete amylase. The group that was fed milk-based formula failed to respond to CCK and secretin administration. Thus, soy- and milk-based formulas result in similar weight gain and similar basal pancreatic enzyme secretion while feeding with soy-based formula selectively increases the trypsin and lipase response to CCK.

Animals↗
PubMed1981

Recurrent abdominal pain and lactose absorption in children.

The association of lactase deficiency with recurrent abdominal pain was investigated. One hundred three white children between the ages of 6 to 14 years with recurrent abdominal pain were evaluated. Sixty-nine underwent lactose tolerance tests and 26 had intestinal biopsies with lactase determinations; 21 of 69 (30.4%) had abnormal lactose tolerance tests and eight of 26 (31%) were lactase deficient. However, 16 of 61 (26.4%) control subjects matched for age and ethnic background exhibited lactase deficiency. Thus, a similar prevalence of lactase deficiency was found in the control and the recurrent abdominal pain groups. Thirty-eight patients with recurrent abdominal pain completed three successive six-week diet trials conducted in a double-blind fashion. An increase above base line value in pain frequency was seen in ten of 21 (48%) lactose malabsorbers and four of 17 (24%) lactose absorbers. After a 12-month milk elimination diet, six of 15 (40%) malabsorbers and five of 13 (38%) absorbers had elimination of their pain. This result compared with improvement occurring in five of 12 (42%) absorbers with recurrent abdominal pain who received a regular diet for one year and suggests that the elimination of lactose will not affect the overall frequency of improvement in recurrent abdominal pain. In addition, the recovery rate from recurrent abdominal pain is similar in both lactose absorbers and nonabsorbers independent of dietary restrictions.

Abdomen↗
PubMed1981

Peptic ulcer in children: the predominance of gastric ulcers.

Thirty-two children with ulcer disease were seen over a four-year period. Twenty-seven children had a primary ulcer and five had an ulcer associated with an acute or chronic illness (secondary ulcer). Antral ulcer was diagnosed most commonly, followed by duodenal ulcer and gastric body ulcer. The ratio of gastric ulcer to duodenal ulcer was 17:11. Diagnosis of ulcer was accomplished by endoscopy in 97% of the patients and by radiography in 70% of those studied. Radiologic accuracy was obtained in 89% with duodenal ulcer but in only 50% of those with gastric ulcer. Children with primary gastric ulcer presented with no evidence of chronicity and 12% had persistence or recurrence of ulcer during follow-up. Eighty-two percent of the children with primary duodenal ulcer presented with chronic symptoms consisting of abdominal pain, nausea, vomiting or recurrent bleeding and 45% had persistence or recurrence of ulcer during follow-up. Children with secondary ulcer all presented with acute symptoms and none had persistence or recurrence. Twenty children were treated prospectively with cimetidine and 11 were treated with antacids. Repeat endoscopy was employed in 16 as a measure of healing. All children with isolated antral ulcer did well clinically, regardless of mode of therapy and of those studied by re-endoscopy all showed complete or substantial healing at six to eight weeks. Treatment of a small group of children with primary duodenal ulcer using cimetidine was initially efficacious, although recurrence of ulcer was noted after cessation of treatment in four of six children given cimetidine. In addition, cimetidine appears to offer no advantage compared to antacids in the treatment of uncomplicated antral ulcer in children.

Adolescent↗
PubMed1981

Immunoglobulin concentrations in the duodenal fluids of infants and children. II. The effect of pancreozymin and secretin.

A study was conducted to determine whether pancreozymin and secretin affect the levels of immunoglobulins in duodenal fluid of children. The subjects consisted of 45 infants and children without gastrointestinal disease. Ig-A concentrations in duodenal fluid were significantly increased (P less than 0.02) after secretion administration (2 U./kg) as compared to resting fluid levels (18.3 +/- 0.8 vs. 12.9 +/- 1.1 mg./gm. protein). Secretin also produced a significant increase (P less than 0.0002) in Ig-M duodenal fluid levels (25.5 +/- 3.6 vs. 13.8 +/- 1.4 mg./gm. protein). Duodenal fluid Ig-G concentrations were not significantly changed in response to secretin (30.7 +/- 2.3 vs. 29.1 +/- 1.2 mg./gm. protein) or to pancreozymin (29.0 +/- 0.8 mg./gm. protein). Pancreozymin administration (2 U./kg) produced a significant decrease (P less than 0.01) in Ig-A concentration (11.2 +/- 0.8 mg./gm. protein) and a significant increase (P less than .0002) in the Ig-M levels of human duodenal fluid (20.8 +/- 1.8 mg./gm. protein).

Adolescent↗
PubMed1980

Immunoglobulin concentrations in duodenal fluid of infants and children.

The immunoglobulin content of duodenal fluid in children at different ages has not as yet been determined, while that of serum, feces, and saliva has been well established. In 92 normal infants, children, and young adults on whom duodenal intubation was performed, duodenal fluid IgA, IgM, and IgG levels were measured. From these data, a developmental profile of immunoglobulins in duodenal fluid from 2 weeks of life to 19 years was obtained. Duodenal fluid IgA, IgM, and IgG appeared to maintain rather constant levels. The grand mean IgA level was lower than the mean IgG level (12.7 +/- 0.8 vs 29.1 +/- 2.5 mg/g of protein). Secretory component was detected in all duodenal fluids. IgG concentrations were greater than those of IgM (29.1 +/- 2.5 vs 13.2 +/- 1.4 mg/g of protein) over all age ranges. The developmental patterns of all immunoglobulins appeared to be different from those observed in serum or saliva with the exception of duodenal fluid IgA, which has a pattern similar to that of salivary IgA.

Adolescent↗