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Biomedical subjects

S R Bloom

Publications and source records attributed to S R Bloom.

At least 1,045 records · Page 58Linked to original sources
PubMed1981

[Coeliac sprue and gut hormones: pathophysiological and clinical aspects (author's transl)].

In adult coeliac sprue patients, intraduodenal instillation of a hypertonic glucose-citric acid solution may release gastrointestinal hormones of the proximal (secretin, gastric inhibitory polypeptide, motilin) and distal (enteroglucagon, neurotensin) small intestine and, indirectly, of the pancreas (glucagon, insulin, pancreatic polypeptide). Characteristic plasma hormone profiles can be measured radioimmunologically. The reduced secretin response reflects most sensitively the impaired function of the small intestine. Exposure of the distal small bowel to greater nutrient loads leads to markedly and constantly elevated plasma levels of enteroglucagon. Only after complete functional as well as morphologic mucosal restoration, the increased enteroglucagon concentrations return to normal. On the other hand, the neurotensin response, which is likewise enhanced in active coeliac sprue, is sooner corrected during treatment. Gastrointestinal hormones with predominantly neurocrine action, such as vasoactive intestinal peptide (VIP), are apparently less affected by coeliac sprue. Pancreatic hormones are involved in the pathophysiology of sprue only indirectly, e. g. via diminished glucose absorption.

Adult↗
PubMed1981

The gut hormone profile of fulminant hepatic failure.

Twenty-five patients with fulminant hepatic failure and grade III or IV hepatic encephalopathy were studied. Plasma insulin, glucagon, pancreatic polypeptide and enteroglucagon were significantly raised. Levels of secretin and gastrin were normal, while motilin concentrations were significantly depressed. Vasoactive intestinal polypeptide was increased in six patients and was significantly higher in those patients who were hypotensive or who had marked prolongation of prothrombin time.

Acute Kidney Injury↗
PubMed1981

Molecular forms of motilin in the mammalian and human gut and human plasma.

Regional specific antibodies and gel permeation chromatography were used to analyze the molecular forms of motilin in the human gut and plasma and in the porcine gut. The same antibodies were also used for immunocytochemical localization of the cell of origin of motilin. Two main molecular forms of motilin were identified, peak I eluting at a volume suggesting a larger molecular weight substance (Kav = 0.16) and peak II coeluting with the porcine motilin standard (Kav = 0.67). Peak I accounted for over 50% of the total motilin immunoreactivity in the human gut, whereas in the porcine intestine it represented less than 5%. Peak I thus appeared to have a greater N-terminal sequence similarity with the porcine motilin standard. Chromatographic analysis of human plasma showed the presence of both immunoreactive peaks in approximately equal amounts which were both suppressed following infusion of somatostatin. Infusion of porcine motilin resulted in the expected rise of plasma immunoreactivity in the peak II position, whereas peak I was significantly depressed, suggesting the possibility of a negative feedback. Immunocytochemistry revealed that both antibodies immunostained equally the non argentaffin cell, which contained small round, electron-dense granules. In addition some argentaffin enterochromaffin cells were stained predominantly with the N-terminal specific antibody.

Adult↗
PubMed1980

[Behavior of plasma insulin and GIP in obese patients subjected to biliopancreatic bypass].

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-Y reconstruction, being the small bowel transected at its midpoint and the enteroenteroanastomosis placed 50 cm proximal to the ileocecal valve. Insulin and GIP fasting and meal-stimulated plasma concentrations were determined in 13 nonobese healthy volunteers, in 13 nonoperated obese patients, in 11 subjects within two months, in 12 subjects four to twelve months, and in 7 subjects fifteen to twenty months after operation. Insulin in the obese patients was significantly higher than in the control group. Postoperatively these patients showed a sharp reduction in basal and postprandial values. Plasma insulin levels, both basally and following the test meal, were very similar in the 15-20 month and the control group. Plasma GIP fasting level, meal-stimulated peak and integrated response in the obese group were higher than in control group. Due to the extreme variability among subjects in the obese group, the difference was significant only for the mean peak response. All values were greatly reduced after surgery. The mean fasting level in the 15-20 month group was very similar to that in the control group, and both peak and integrated responses were significantly lower than in the preoperative and control groups.

Fasting↗
PubMed1980

[Behavior of plasma enteroglucagon and neurotensin in obese patients subjected to biliopancreatic bypass].

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-Y reconstruction, being the small bowel transected at its midpoint and the enteroenteroanastomosis place 50 cm proximal to the ileocecal valve. Neurotensin and enteroglucagon fasting and meal-stimulated plasma concentrations were determined in 13 nonobese healthy volunteers, in 13 nonoperated obese patients, in 11 subjects within two months, in 12 subjects four to twelve months and in 7 subjects fifteen to twenty months after operation. Basal plasma enteroglucagon was significantly higher in the obese group than in the controls. However, there was no difference in the peak response, and a decrease, though not statistically significant, was seen in the integrated response. All three values were strikingly augmented in the 0-2 month group, with a highly significant difference from the preoperative group. The 4-12 and 15-20 month groups, in comparison with the 0-2 month group, showed no changes in fasting levels, a clear-cut decreased peak response and a sharp progressive reduction in integrated response, mean value in the 15-20 month group being significantly lower than that of 0-2 month group. Neurotensin basal and meal-stimulated peak plasma concentrations in the obese group were significantly higher than in the control group, whilst the integrated response was almost identical in the two groups. In postoperative groups no substantial changes in fasting levels and an increase in the peak response were observed, with a considerable progressive rise in the integrated response.

Fasting↗
PubMed1980

[Behavior of plasma pancreatic polypeptides and motilin in obese patients subjected to biliopancreatic bypass].

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-y reconstruction, being the small bowel transected at its midpoint and the enteroenteroanastomosis placed 50 cm proximal to the ileocecal value. Pancreatic polypeptide (PP) and motilin fasting and meal-stimulated plasma concentrations were determined in 13 nonobese healthy volunteers, in 13 nonoperated obese patients, in 9 subjects within two months, in 12 subjects four to twelve months, and in 7 subjects fifteen to twenty months after operation. There were no significant differences in PP fasting levels between either the obese and control groups or between the postoperative groups and the preoperative group. Both meal-stimulated peak and integrated response values were similar in the obese and control groups, and were strikingly and progressively reduced postoperatively, with statistically significant difference between all postoperative groups and preoperative group. Mean plasma motilin fasting and peak values were higher in the obese group than in the control group, and significantly reduced in the 4-12 and 15-20 month group. Despite the huge variability among data, the integrated response in the 0-2 month group was significantly decreased in comparison with the preoperative group, while a subsequent progressive increase was shown by the 4-12 and 15-20 month groups.

Fasting↗
PubMed1980

[Behavior of plasma gastrin in obese subjects subjected to biliopancreatic bypass].

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-Y reconstruction, small bowel being transected at its midpoint and the enteroenterostomy placed 50 cm proximal to the ileocecal valve. Plasma fasting and meal-stimulated gastrin concentrations were measured by radioimmunoassay in 13 nonobese healthy volunteers, 13 pre-surgery obese patients, 11 patients within two months, 12 patients between four and twelve months and 7 patients between fifteen and twenty months after operation. There were no significant differences in fasting and meal-stimulated peak plasma gastrin levels between obese group and the control group and between any of the postoperative groups and the preoperative group. The 15-20 month post-surgery group mean fasting value was lower than in the other groups, whilst the mean peak value was unchanged. Integrated gastrin response was significantly higher in this group than in the preoperative group.

Biliary Tract Surgical Procedures↗
PubMed1980

Serum trypsin concentration and pancreatic trypsin secretion in insulin-dependent diabetes mellitus.

Fasting serum trypsin concentration and pancreatic trypsin output, stimulated by secretin and cholecystokinin-pancreozymin, were measured in 18 patients with insulin-dependent diabetes, to assess a possible correlation between these two indices of exocrine pancreatic function. Serum trypsin concentration was subnormal in 13, and pancreatic trypsin output was decreased in 14 patients, but there was no significant correlation between the two measurements. There was no correlation between serum trypsin and residual beta cell function measured by plasma C-peptide immunoreactivity (CPR). After an interval of four years serum trypsin measurements were repeated in 11 subjects. All individual trypsin levels were lower than the previous results, the difference being highly significant (t = 9.0; p < 0.001). Serum trypsin concentration therefore represents a qualitative index of reduced exocrine pancreatic function in diabetes, but has no value in quantitating the degree of deficiency.

Adolescent↗
PubMed1980

Breast vs bottle: endocrine responses are different with formula feeding.

Differences in pancreatic and gut-hormone release between breast-fed and bottle-fed infants have not been documented although these hormones may play a key role in postnatal adaptation. In a study of 77 six-day-old healthy term infants, bottle-fed neonates ('Cow and Gate Premium') had significant changes in plasma-concentrations of insulin, motilin, enteroglucagon, neurotensin, and pancreatic polypeptide after feeding, whereas in breast-fed infants these changes were reduced or absent. Basal levels of gastric inhibitory polypeptide, motilin, neurotensin, and vasoactive intestinal peptide were also higher in the bottle-fed infants than in those who were breast-fed. These findings may partly explain differences in the deposition of subcutaneous fat and in stool frequency between breast-fed and bottle-fed neonates.

Bottle Feeding↗
PubMed1980

Effect of neurotensin on gastric function in man.

Neurotensin is a peptide recently discovered in the human ileum and it is released into plasma after ingestion of food. Neurotensin was infused intravenously into 12 healthy volunteers at a mean dose of 2.4 pmol/kg/min, the mean rise in plasma levels being 89 +/- 8 pmol/l. An inhibition of both gastric acid and pepsin output, and also a delay in gastric emptying of oral glucose, were observed. Neurotensin may therefore have a physiological role in modulating gastric function in man.

Adult↗
PubMed1980

Enkephalin-, VIP- and substance P-like immunoreactivity in the carotid body.

The carotid body type I cell contains amines and has features, both morphological and cytochemical, which indicate that it may also produce a peptide. Many regulatory peptides are now known to be present in both central and peripheral tissues. In the periphery these neuropeptides occur in both classical endocrine (APUD) cells and the neurones of the autonomic nervous system. We have now investigated the possible presence of neuropeptides in the cat carotid body using both immunocytochemistry and radioimmunoassay. Met- and Leu-enkephalin-like material occurred in considerable quantities in carotid body extracts and enkephalin-like immunoreactivity was localised in type I cells. Both vasoactive intestinal polypeptide (VIP)- and substance P-like immunoreactivity was also present but was localised in nerve fibres distributed throughout the organ. These active neuropeptides are widely distributed in mammalian tissues, forming a diffuse regulatory system which now seems to include the carotid body.

Animals↗
PubMed1980

Neural and hormonal peptides in rectal biopsy specimens from patients with Chagas' disease and chronic autonomic failure.

The neural and hormonal peptide content of rectal biopsy specimens from 10 patients with chronic autonomic failure, 10 patients with chronic gastrointestinal Chagas' disease, and 13 controls was studied with radioimmunoassay and immunocytochemistry. In the patients with Chagas' disease the mean concentrations of rectal vasoactive intestinal polypeptide, enteroglucagon, substance P, and somatostatin were all less than half of those in controls and in patients with chronic autonomic failure. Immunocytochemistry revealed a considerable reduction in the number and immunostaining of the peptide-containing cells and nerves. Concentrations of regulatory peptides in the rectum are thus reduced in association with intrinsic but not extrinsic autonomic neuropathy.

Autonomic Nervous System↗
PubMed1980

Peptide-containing neurones connect the two ganglionated plexuses of the enteric nervous system.

The enteric nervous system (ENS) of the mammalian gut consists principally of two ganglionated plexuses, the myenteric and submucous, which are embedded in the gut wall. Little is known about the anatomical and functional connections between the two plexuses and further clarification of their relationship is of central importance for the understanding of the ENS. In the present study we have approached this problem in a new way, using methods we have previously developed for maintaining the myenteric and submucous plexuses separately in vitro for several weeks. In an immunohistochemical study of these preparations and also of sections from normal and extrinsically denervated gut wall, we have found evidence for reciprocal projections between the myenteric and submucous plexuses, by nerve fibres containing two putative neurotransmitters, vasoactive intestinal polypeptide (VIP) and substance P (ref. 5) (see Fig. 1). Our observations were supported by radioimmunoassay of tissue extracts. These results suggest that one of the roles of these peptides in the gut is to coordinate the function of the two enteric plexuses.

Animals↗