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Biomedical subjects

A Schafmayer

Publications and source records attributed to A Schafmayer.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Effect of pancreatic innervation on exocrine secretory performance of the pancreas].

In the present study we examined the influence of extrinsic pancreatic innervation on exocrine pancreatic response to secretin, caerulein, tryptophan and fat, and furthermore the amino acid- and fat-stimulated release of neurotensin and CCK in dogs. Denervation of the pancreas did not alter secretory response to secretin and caerulein, whereas transsection of the extrinsic nerves significantly diminished the protein response to tryptophan and fat. Release of CCK was not altered by pancreatic denervation. However, fat-evoked neurotensin plasma levels were significantly increased after denervation of the pancreas.

Animals↗
PubMed1992

Influence of different methods of vagotomies on the secretion of cholecystokinin in dogs.

In six dogs, a selective proximal vagotomy, gastric vagotomy, and truncal vagotomy were performed successively. Basal and postprandial cholecystokinin (CCK) concentrations in the peripheral blood were measured by radioimmunoassay. After all the different types of vagotomy, especially after truncal vagotomy, an increased postprandial secretion of CCK was found compared with the healthy animal. Possible causes discussed are the cutting of vagal fibers, which might inhibit the secretion of CCK cells, and the changed gastric and pancreatic secretion.

Animals↗
PubMed1992

Endocrine response to intragastric and intravenous glucose challenge in the denervated dog pancreas.

The functional connection between the gut and the islet cells comprises nerves and gastrointestinal hormones. In this study, we quantified the incretin effect and the glucose tolerance (KG value) before and after denervation of the pancreas in dogs in order to find out whether the incretin effect is mediated by nerves. The participation of nerves was estimated by comparing metabolic tests before and after total extrinsic pancreatic denervation in 10 dogs. Fifty-nine percent of the insulin response after intragastric glucose was calculated preoperatively to be the result of incretin factors, a value similar to the 62% found in the postoperative series (with denervated pancreas). The response of GIP to intragastric glucose was not significantly different between pre- and postoperative tests. The KG values pre- and postoperative were in the same range. From our data, we conclude that extrinsic nerves of the pancreas do not seem to play an important role in mediating glucose homeostasis in dogs.

Animals↗
PubMed1992

Role of octreotide in the prevention of postoperative complications following pancreatic resection.

Though morbidity and mortality rates following pancreatic resection have improved in recent years, they are still around 35% and 5%, respectively. Typical complications, such as pancreatic fistula, abscess, and subsequent sepsis, are chiefly associated with exocrine pancreatic secretion. In order to clarify whether the perioperative inhibition of exocrine pancreatic secretion prevents complications, we assessed the efficacy of octreotide, a long-acting somatostatin analogue. We conducted a randomized, double-blind, placebo-controlled, multicenter trial in 246 patients undergoing major elective pancreatic surgery. Patients were stratified into a high-risk stratum (limited to patients with pancreatic and periampullary tumors) or low-risk stratum (patients with chronic pancreatitis). Patients received octreotide (3 x 100 micrograms) or placebo subcutaneously for 7 days perioperatively. Eleven complications were defined: death, leakage of anastomosis, pancreatic fistula, abscess, fluid collection, shock, sepsis, bleeding, pulmonary insufficiency, renal insufficiency, and postoperative pancreatitis. Two hundred patients underwent pancreatic head resection, 31 patients underwent left resection, and 15 patients had other procedures. The overall mortality rate within 90 days was 4.5%, with 3.2% in the octreotide group and 5.8% in the placebo group. The complication rate was 32% in the patients receiving octreotide (40 of 125 patients) and 55% in patients receiving placebo (67 of 121 patients) (p less than 0.005). In the patients in the high-risk stratum, complications were observed in 26 of the 68 (38%) patients treated with octreotide and in 46 of 71 (65%) patients given placebo (p less than 0.01). Whereas in patients in the low-risk stratum, the complication rate was 25% (14 of 57 patients) in those treated with octreotide and 42% (21 of 50 patients) in patients given placebo (p = NS). The perioperative application of octreotide reduces the occurrence of typical postoperative complications after pancreatic resection, particularly in patients with tumors.

Double-Blind Method↗
PubMed1992

Effect of total extrinsic denervation and atropine on HCl-stimulated pancreatic exocrine secretion and CCK release in conscious dogs.

In 10 dogs with pancreatic fistulas, we studied the effect of extrinsic pancreatic innervation and atropine on protein and bicarbonate secretion and cholecystokinin (CCK) release after intraduodenal perfusion with HCl. Before and after extrinsic denervation of the pancreas, the dogs were given 0.05 M HCl in increasing doses (1.5-48 mmol/h). Tests were repeated with atropine. Increasing doses of HCl resulted in a dose-dependent release of protein and bicarbonate output in both the intact and the denervated pancreas. However, pancreatic denervation significantly decreased pancreatic secretion in response to low loads but not to high loads of HCl. HCl-stimulated CCK release was not altered by pancreatic denervation. In the intact pancreas, atropine significantly reduced bicarbonate and protein response to low loads but not to high doses of HCl. In the denervated gland, atropine had no further inhibitory effect on exocrine pancreatic secretion. Furthermore, atropine showed no influence on HCl-stimulated CCK release under either condition.

Animals↗
PubMed1992

[Endoscopic hernia repair].

A laparoscopic procedure for surgical hernia repair is reported. In comparison to other methods we do not only remove the peritoneal sac, but close although the inguinal canal with a nonresorbable marlex mesh. Up to now we practiced this technique in 35 patients. First post-operative results are encouraging but nothing can be said about longterm results, especially the recurrence rate.

Adolescent↗
PubMed1992

[Influence of extrinsic denervation of the pancreas on food-stimulated pancreas secretion and cholecystokinin and neurotensin release in the dog].

In the present study we examined the effect of extrinsic pancreatic denervation on meal-stimulated pancreatic exocrine secretion and the release of neurotensin and CCK in dogs. Denervation of the pancreas significantly decreased protein output from preoperatively 16,661 +/- 1824 mg x 150 min to 2033 +/- 316 mg x 150 min postoperatively (p less than 0.001), and bicarbonate secretion from 297.5 +/- 36 mmol x 150 min to 104.85 +/- 16 mmol x 150 min (p less than 0.01). Release of neurotensin and CCK was not altered by interruption of the extrinsic pancreatic nerves. Our findings are consistent with the hypothesis that pancreatic secretory response to a meal is predominantly mediated by neutral extrinsic reflexes.

Animals↗
PubMed1991

[New aspects of large intestine surgery].

Use of the biofragmentable anastomosis ring led to no significant differences in clinical results when compared with the use of conventional suture techniques. The patients' prognosis and the efficiency of perioperative portal chemotherapy are impaired by perioperative blood transfusions in colorectal cancer. Regarding proved risk factors for development of local recurrence, there is no significant difference between low anterior resection and abdominoperineal excision. Lymph node dissection is one important factor for ensuring an adequate oncological strategy in colorectal surgery.

Colectomy↗
PubMed1991

Dissociation of cholecystokinin and pancreaticobiliary response to intraduodenal bile acids and cholestyramine in humans.

The role of intraduodenal bile acids in the regulation of cholecystokinin (CCK), pancreatic polypeptide (PP), and secretin as well as exocrine pancreatic and biliary secretion was investigated by means of a duodenal marker perfusion technique in volunteers. The following solutions were perfused: (1) liquid test meal, (2) test meal with 6 g cholestyramine, (3) test meal with 2 g chenodeoxycholic acid (CDC), (4) test meal with 6 g cholestyramine and 2 g CDC, (5) 6 g cholestyramine alone, and (6) 2 g CDC alone. The test meal caused an immediate increase in CCK and PP plasma levels, whereas secretin was not significantly altered. CCK release was further enhanced by addition of cholestyramine, whereas CDC inhibited release. The stimulatory effect of cholestyramine was abolished by CDC. CDC alone and in combination with the test meal stimulated secretin release. The response of PP to the test meal was not altered by addition of either compound. Cholestyramine and CDC alone caused only a very small increase in CCK levels, whereas PP was stimulated to nearly postprandial values. Meal-stimulated pancreatic and biliary secretion was significantly enhanced by cholestyramine, CDC, and the combination of both. CDC and cholestyramine alone each stimulated enzyme and bile secretion to a greater extent than the test meal. We conclude that intraduodenal bile salts are a modulator of postprandial CCK release. Changes in exocrine pancreatic and biliary and PP secretion do not necessarily parallel CCK concentrations, suggesting that different mediators are involved in the observed bile acid-induced changes in humans.

Adult↗
PubMed1991

Total denervation of the pancreas does not alter the pancreatic polypeptide-induced inhibition of pancreatic exocrine secretion in dogs.

Pancreatic polypeptide (PP) is a potent inhibitor of pancreatic exocrine secretion in vivo. The mechanism of pancreatic inhibition by PP is unknown, but the absence of PP receptors on pancreatic exocrine cells makes a direct effect of this hormone on the gland unlikely. In this study, we investigated the hypothesis that PP exerts its inhibitory effect via extrinsic neural pathways. Ten dogs with gastric and pancreatic fistulas were given an intravenous infusion of 250 ng/kg-1 h-1 secretin and 50 ng/kg-1 h-1 caerulein over 3 h. One hour after starting the infusion, 400 pmol kg-1 h-1 porcine PP were administered over 1 h. Pancreatic bicarbonate and protein secretions were measured. Later, the pancreas was extrinsically denervated. PP infusion decreased bicarbonate secretion in the intact gland by 47% and in the denervated pancreas by 57%. Protein secretion was diminished by exogenous PP by 31% in the intact and by 44% in the denervated pancreas. Despite pancreatic denervation, PP still exerted a significant inhibitory effect. Atropine infusion completely blocked the inhibitory effect of PP on caerulein-stimulated pancreatic protein secretion both in the intact and denervated pancreas and of secretion-evoked bicarbonate output in the denervated gland. We conclude that the inhibitory action of the hormone is not mediated via extrinsic neural pathways of the pancreas, but PP may exert its effect via intrinsic atropine-sensitive mechanisms.

Animals↗
PubMed1991

Treatment of iatrogenic common bile duct injury during laparoscopic cholecystectomy through the laparoscopic insertion of a T-tube stent.

Iatrogenic injury to the common bile duct during laparoscopic cholecystectomy has previously necessitated an immediate laparotomy to alleviate bile leakage. In the course of 171 laparoscopic cholecystectomies performed at our hospital, intraoperative common bile duct injuries occurred in 2 patients. Each case was successfully treated using a laparoscopically placed T-tube, thus avoiding the need for a laparotomy. This novel intraoperative procedure successfully treated common bile duct injuries without resulting in postoperative complications.

Adult↗
PubMed1991

Interaction of the cholinergic system and cholecystokinin in the regulation of endogenous and exogenous stimulation of pancreatic secretion in humans.

Pancreatic enzyme secretion is regulated in humans by the cholinergic system and by cholecystokinin (CCK). The interaction between both regulatory systems in response to exogenous and endogenous stimulation was analyzed in the present study using the cholinergic antagonist atropine and the CCK antagonist loxiglumide. A dose-dependent stimulation of pancreatic enzyme output was achieved either by duodenal perfusion of graded caloric loads or by IV infusion of increasing doses of cerulein. Prestimulated pancreatic secretion was inhibited by atropine and loxiglumide. Atropine furthermore almost completely blocked meal-stimulated pancreatic secretion, whereas loxiglumide caused 60% inhibition. The enzyme response to graded doses of exogenous CCK was significantly inhibited by atropine and loxiglumide. Plasma levels of CCK were not altered by atropine but increased with infusion of loxiglumide. This study supports the concept that pancreatic enzyme secretion is predominantly dependent on a cholinergic tone and that CCK modulates the enzyme-secretory response.

Adult↗
PubMed1991

Plasma concentrations of neurotensin and CCK in patients with chronic pancreatitis with and without enzyme substitution.

The peptide hormones neurotensin (NT) and cholecystokinin (CCK) are commonly attributed with a physiological role in the stimulation of exocrine pancreatic secretion. However, on the other hand, little is known about the effect of diminished exocrine pancreatic function and of the resulting maldigestion on postprandial plasma levels of these two gastrointestinal peptides. We investigated, therefore, the effect of enzyme substitution therapy on the magnitude and time course of plasma concentrations of both hormones in patients suffering from severe chronic pancreatitis. Pancreatic insufficiency led to elevated NT-concentrations, in response to a standard meal, which could be reduced by enzyme replacement therapy. Prior to enzyme therapy, the mean integrated postprandial release of NT amounted to 2800 +/- 250 pg/ml after 60 min in patients with severe chronic pancreatitis. This amount was significantly reduced to 1250 +/- 150 pg/ml after 60 min after enzyme therapy, compared to 810 +/- 90 pg/ml after 60 min in healthy volunteers after the standard meal. The integrated postprandial CCK level in patients investigated was significantly lower (35 +/- 4.8 pmol/L after 60 min) without any substitution therapy, compared to the integrated peptide amount in healthy volunteers (145 +/- 13.5 pmol/L after 60 min). Enzyme therapy in patients suffering from chronic pancreatitis led to an increased postprandial CCK-level (80 +/- 9.6 pmol/L after 60 min). Elevated CCK-plasma concentrations have not been demonstrated in these patients with pancreatic insufficiency. We therefore suggest that CCK might not play a major role in feedback regulation in patients with chronic pancreatitis. However, in light of elevated NT plasma concentrations in patients with chronic pancreatitis, NT-mediated influence on the pancreas deserves further study.

Amylases↗
PubMed1991

[Neurotensin liberation during the consumption of mineral water from Bad Mergentheimer Karlsquelle].

The contraction of the gallbladder mainly mediated by CCK after oral administration of pharmacological doses of magnesium sulfate is familiar. The same applies to the cholekinetic action of courses of sulfatic mineral water treatment. It was demonstrated in 12 patients in a controlled study that besides other known secretions of gastrointestinal hormones, there is also a significant rise of the plasma level of neurotensin when Bad Mergentheimer Karlsquelle mineral water containing sulfate (3.7 g SO4/l) is drunk on an empty stomach (300 ml, 26 degrees C). This was significantly greater (basal values 6.8 +/- 4.1 pg/ml and a maximum of 15.7 +/- 8.1 pg/ml after 40 min) than in a control group consisting of the same patients who had drunk tapwater. Whereas the involvement of the neuropeptide neurotensin in the regulation of the exocrine functions of the pancreas has been established, its effect in the regulation of gallbladder contraction is probably of rather minor significance compared to CCK.

Adult↗
PubMed1991

[Disorders of wound healing of the sacral cavity after abdomino-perineal resection of the rectum].

In 95 patients it was necessary to perform abdominoperineal resection and colostomy due to malignant tumours of the rectum, the anus, as well as gynaecological tumours. After standardized preoperative preparation and comparable operative techniques in more than 93 per cent of the cases we performed suction drainage of the sacral cavity. In 86 per cent we observed primary perineal wound closure and the patients were spared lengthy secondary wound healing.

Adult↗
PubMed1990

Cholecystokinin is a regulator of intestinal phase-stimulated PP release.

The purpose of this study was to determine the role of CCK during the intestinal phase of pancreatic polypeptide (PP) release in man. We first compared the PP response to exogenous caerulein infusion in the presence or absence of either loxiglumide (a specific CCK antagonist) or atropine in six healthy subjects. In the second part of the study, a meal was perfused to the duodenum with and without either loxiglumide or atropine. Both loxiglumide and atropine completely abolished the PP response to exogenous or endogenous stimulation (P less than 0.05). We conclude that CCK participates in the intestinal phase of PP secretion.

Adult↗
PubMed1990

Measurement of tissue cholecystokinin (CCK) concentrations by bioassay and specific radioimmunoassay: characterization of the bioactivity of CCK-58 before and after tryptic cleavage.

Cholecystokinin (CCK) was measured in an extract of porcine brain by a bioassay system based on the enzyme release from isolated pancreatic acini and a specific radioimmunoassay. The tissue extract represented a crude peptide preparation of porcine brain that contained several molecular forms of CCK, most of them of high molecular weight including CCK-58. The different molecular forms of CCK in the porcine brain extract were isolated by high performance liquid chromatography (HPLC). Determination of CCK-like bioactivity and immunoreactivity after HPLC was performed in parallel by bioassay and radioimmunoassay, respectively CCK-58 was the most abundant molecular form in the porcine brain extract, followed by CCK-33, and CCK-8. Both assay systems measured similar relative concentrations of all different molecular forms of CCK. To elucidate the biological potency of CCK-58 before and after tryptic cleavage, a CCK-58-enriched fraction was prepared by HPLC. Part of this material was quantitatively cleaved by trypsin resulting in the formation of small molecular forms of CCK. Bioactivity and immunoreactivity of equal amounts of cleaved and uncleaved material (= CCK-58) were determined by bioassay and radioimmunoassay in parallel. Cleavage of CCK-58 increased CCK-like bioactivity by 260% and CCK-like immunoreactivity by 310%. These results indicate that in a rat pancreatic acini system, porcine CCK-58 exerts 25-30% bioactivity compared to smaller CCK forms. The specific CCK antiserum G-160 seems to possess 25-30% affinity to CCK-58 in comparison to trypsin-cleaved CCK-58. It can be concluded that this antiserum exhibits an affinity to different molecular forms of CCK which parallels their relative bioactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗