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Biomedical subjects

A Schafmayer

Publications and source records attributed to A Schafmayer.

At least 55 records · Page 3Linked to original sources
PubMed1990

Cholecystokinin release by gastric distension--an atropine-sensitive mechanism.

The effect of gastric distension on plasma cholecystokinin (CCK), pancreatic polypeptide (PP) and gastrin concentrations was investigated in healthy volunteers. Fundic and antral distension was achieved by balloons attached to a gastric tube and inflated with 300 and 600 ml and 100 and 200 ml of air for fundic and antral distension, respectively. Gastric juice was continuously aspirated. Fundic distension was additionally studied during a concomitant intravenous infusion of atropine (5 micrograms/kg/h) or a bolus injection of propranolol (2 mg). Fundic distension with 300 ml caused a significant increase in PP release (+17% above basal). Distension with 600 ml significantly stimulated CCK (+81%), gastrin (+31%) and PP output (+74%) over 30 min. Atropine completely blocked PP release and almost abolished CCK release, whereas gastrin output was enhanced. Propranolol did not prevent CCK release induced by fundic distension, whereas gastrin and PP responses were diminished. Antral distension did not cause any significant changes in hormone response. In conclusion, we demonstrated a gastric phase of CCK release which is atropine sensitive, but not influenced by propranolol.

Adult↗
PubMed1990

Contribution of neurotensin to the entero-pancreatic axis.

Plasma neurotensin concentrations are markedly elevated in patients with severe exocrine pancreatic insufficiency. We therefore investigated whether the exocrine pancreatic function could influence postprandial neurotensin plasma concentrations. Subsequently, we tested the hypothesis that this peptide hormone is involved in regulation of pancreatic secretion. When pancreatic juice is diverted from modified Herrera fistulas in dogs, a simultaneous application of physiological amounts of lipase reduces the elevated plasma neurotensin concentrations. On the other hand, immunoneutralisation of the circulating neurotensin inhibits pancreatic secretion. This suggests a physiological role of neurotensin in the regulation of the exocrine pancreas via an entero-pancreatic axis.

Animals↗
PubMed1990

Cholecystokinin receptor antagonist loxiglumide: influence on bilio-pancreatic secretion and gastrointestinal hormones in man.

We characterized the effect of the specific cholecystokinin (CCK) receptor antagonist loxiglumide (CR 1505) on gallbladder contraction, pancreatic enzyme output and plasma CCK concentrations determined by radioimmunoassay and bioassay. Gallbladder emptying and bilirubin output in response to the intraduodenal administration of a mixed liquid meal were completely inhibited by an intravenous infusion of loxiglumide (10 mg/kg/h). In contrast, meal-stimulated pancreatic enzyme secretion was diminished by only 30-40%. CCK concentrations in response to the test meal were 3-fold higher during infusion of loxiglumide, as determined by radioimmunoassay. In the absence of the antagonist, the bioassay measured CCK plasma levels identical to those determined by radioimmunoassay. In the presence of loxiglumide, CCK-like bioactivity was not detectable, indicating that the plasma concentrations of the CCK receptor antagonist were sufficient to abolish all circulating CCK-like bioactivity. We conclude that fasting volume and meal-induced contraction of the gallbladder are controlled by CCK. Postprandial pancreatic enzyme secretion, however, is mainly mediated by non-CCK-dependent mechanisms. Plasma CCK-like immunoreactivity is increased by loxiglumide, whereas plasma CCK-like bioactivity is zero in the presence of an CCK-receptor antagonist.

Adult↗
PubMed1990

[Diaphragmatic injuries, classification and therapy].

Injuries of the diaphragm are caused either by direct or indirect violence. In all such ruptures various portions of the abdominal viscera may have ascended into the thoracic cavity. The clinical manifestations are unpredictable and of infinite variety, and especially in massively traumatized patient masked by other injuries. A presumptive preoperative diagnosis of diaphragmatic injury from chest x-ray findings is only possible in about 50% of the cases. In other cases the diagnosis can be confirmed by water.soluble contrast enema into the stomach or colon. Rupture of the diaphragm is a strong indication for operation. In cases of fresh rupture we attempt repair of the diaphragm through a laparotomy incision. In old diaphragmatic rupture we prefer a thoracotomy incision.

Diagnosis, Differential↗
PubMed1990

[Pancreatico-pleural fistula. Clinical aspects and therapy of a rare disease entity].

We report of 2 patients with pancreatic-pleural fistulas in chronic pancreatitis. In both cases abdominal symptoms were missed, the primary clinical manifestation was a recurrent pleural effusion with a high content of amylase. Endoscopic retrograde cholangiopancreaticography is necessary for a precise evaluation of the fistula and is indispensable to the surgical therapy. Computed tomography and ultrasonography showed in both cases a pancreatic pseudocyst. Our recommendation is surgical therapy when the fistula is not closed spontaneously within 2 weeks. Both patients were successfully treated by a left pancreatectomy.

Adult↗
PubMed1989

Effect of atropine on feedback regulation of pancreatic secretion in rats.

In the present study the effect of atropine on feedback regulation of pancreatic function was investigated in male rats. Orogastric tube feeding of a single dose of the protease inhibitor camostate (100 mg) caused a 6-fold increase in plasma CCK. This was accompanied by a 50% decrease in pancreatic enzyme content for up to 6 h. The effect of i.v. infusion of atropine (100 micrograms.kg-1.h-1) was studied 60 and 180 min after camostate feeding. Atropine completely abolished the decrease in enzyme content 180 min after camostate feeding. The stimulated CCK plasma levels were significantly lowered by the infusion of atropine 60 min, but not 180 min, after feeding of camostate. It is discussed that a cholinergic pathway mediates CCK release in the early phase of feedback regulation of pancreatic function.

Amylases↗
PubMed1989

Differential effects of atropine and a cholecystokinin receptor antagonist on pancreatic secretion.

The present study evaluates the effect of atropine and of the cholecystokinin receptor antagonist loxiglumide on feedback regulation of basal pancreatic secretion in 6 healthy volunteers. The intraduodenal instillation of the protease inhibitor camostate reduced enzymatic activities of trypsin and chymotrypsin by 80%. This was accompanied by a strong increase in amylase and lipase output. The intravenous infusion of atropine (5 micrograms/kg.h) completely abolished the stimulatory effect of camostate on enzyme output. The infusion of loxiglumide (10 mg/kg.h) caused no changes in camostate-induced stimulation of enzyme output. Plasma levels of cholecystokinin were not altered after intraduodenal instillation of camostate whether atropine, loxiglumide, or saline were infused. We suggest that the protease inhibitor camostate, by inhibition of the enzymatic activity of trypsin and chymotrypsin, interferes with feedback regulation of basal pancreatic secretion in humans, and this mechanism is predominantly mediated by the cholinergic system.

Adult↗
PubMed1989

The influence of the duodenal passage on postprandial neurotensin release in dogs.

All types of gastric resections induce an abnormal release of gastrointestinal hormones. The missing duodenal passage seems to be the most important factor for these disturbances. In the present study we have examined the effect of exclusion and restoration of the duodenal passage on the postprandial release of neurotensin in dogs. After feeding a standard canned dog meal, exclusion of the duodenal passage by a Billroth-II-resection caused a significant increase in postprandial neurotensin release compared to the control group (peak levels 52 +/- 5.6 to 29 +/- 6 pg/ml preoperatively, integrated output 2132 +/- 228 to 3604 +/- 213 pg/ml x 150 min. p less than 0.05). Reconstruction of the duodenal passage by the Biebl-Henly-Soupault-procedure tended the elevated neurotensin levels towards normal (peak levels 36 +/- 4.8 pg/ml, integrated output 2448 +/- 236 pg/ml x 150 min., p less than 0.05). From our data we conclude that changes in intestinal transit time are responsible for the pathological increase in neurotensin release after exclusion of the duodenal passage.

Animals↗
PubMed1989

The biological relevance of N-terminal neurotensin fragments in the regulation of exocrine pancreas secretion.

Stimulation of the exocrine pancreas is one of the biological effects attributed to the tridecapeptide neurotensin (NT). Only the C-terminal 8-13 fragment with its extremely short plasma half-life in the peripheral circulation was considered to be necessary for biological activity. The N-terminal fragments that are detectable in peripheral blood in much greater concentrations were considered to be of no importance. In order to elucidate the biological relevance of these N-terminal fragments, five dogs were infused with neurotensin at a rate (50 pmol/kg/h) that had been determined to give physiological plasma concentrations. Pancreatic secretions were collected from previously implanted modified Herrera pouches. The effects of the N-terminal fragments NT 1-8 and NT 1-11 on the exocrine pancreas secretion were tested in the same way. It was possible for the first time to demonstrate a biological effect of the N-terminal fragments found in the postprandial circulation in vivo. The plasma concentrations determined by radioimmunoassay remained within the physiological range (less than 40 pg/ml). These N-terminal neurotensin fragments may therefore participate in the hormonal regulation of the exocrine pancreas secretion.

Animals↗
PubMed1989

Do bile acids exert a negative feedback control of cholecystokinin release?

The influence of intraduodenal bile deficiency due to chronic bile duct obstruction and acute exogenous administration of bile acids on plasma cholecystokinin (CCK) and pancreatic polypeptide (PP) was investigated. Fourteen patients with tumor-induced bile duct stenosis and five healthy volunteers were given a liquid test meal. Four of the patients had a simultaneous pancreatic duct stenosis. On another day 4 g chenodeoxycholic acid were administered concomitantly with the liquid test meal in six of the patients and all controls. Basal and meal-stimulated plasma CCK did not differ between patients and controls. A pancreatic duct stenosis, which was associated with diminished plasma PP concentrations, had no influence on plasma CCK release. Exogenous bile acids significantly reduced the postprandial CCK response in both groups. Bile-induced inhibition was significantly greater in patients than in controls (75 +/- 7% and 44 +/- 11%, respectively; p less than 0.05). It is concluded that intraduodenal bile is an important modulator of the postprandial secretory activity of the CCK cell. Although chronic intraduodenal bile acid reduction in tumor-induced biliary duct stenosis did not influence plasma CCK levels, a negative feedback control of plasma CCK by acute bile acid administration could be demonstrated.

Adult↗
PubMed1989

[Stapler-dependent surgical procedures in the colorectal area].

Since its introduction, stapling has gained considerable interest in colon surgery. The double stapling technique is a further development. From 1984 to 1989, 110 low anterior resections were performed at the Department of General Surgery, University of Goettingen. In 73 patients anastomosis was performed by double stapling; in 37 cases the EEA stapler was used. The double stapling group had an insufficiency rate of 2.7% compared with 5.4% in the EEA group. Another useful indication for stapler techniques is a reconstructive operation according to the Hartmann procedure. In none of 43 such interventions between 1983 and 1988 was insufficiency of the anastomosis seen. Another useful employment of staplers is construction of colonic reservoirs after proctocolectomy.

Anastomosis, Surgical↗
PubMed1989

[Does the stomach balloon modify the function of the esophagus and lower esophageal sphincter, stomach emptying and release of gastrointestinal peptides?].

The Willmen gastric bubble has been used as an adjunct to weight loss in morbidly obese patients. 35 patients with morbid obesity were studied with routine manometry, esophageal 24-h-pH-measurement, and gastric emptying studies before and 4 weeks after bubble placement. During emptying studies blood samples were taken to measure gastrin, PP, CCK, VIP, neurotensin and insulin. No patient developed heartburn or regurgitation after bubble placement. Esophageal motility and LES function remained unchanged. There was no important pathological gastroesophageal reflux before and after gastric bubble. The gastric emptying time of solid food was unchanged by gastric bubble placement and the emptying time of liquids was accelerated up to normal. In patients with fasting gastrin levels less than 20 pg/ml at the beginning of the first test we found no differences in gastrin release before and after bubble insertion. In patients with primary high fasting values gastrin release was significantly increased. CCK, VIP, neurotensin and insulin levels were unchanged. With PP we measured significantly raised fasting levels after gastric bubble. We conclude that esophageal and LES functions are not altered by Willmen gastric bubble placement and that primary retardation of fluids is changed to normal. Bubble induced gastric tension increases fasting PP. In case of high fasting gastrin the bubble leads to an extremely high food response without any clinical signs.

Adult↗
PubMed1989

[Hemodynamic characteristics of necrotizing pancreatitis].

Seventy-one patients with necrotizing pancreatitis in stages II and III were treated at the surgical intensive care unit in the authors' hospital, between 1982 and 1986. Pathological courses in 23 patients were so severe that a pulmonary catheter had to be applied to monitor haemodynamic changes. Seventeen of these 23 patients died (73.9 per cent), while six survived. The gravest difference between these two groups was relating to vasculopulmonary resistance, which went up strongly in the first group (428 +/- 19 dyn X sec X cm-5) and stayed moderate in the second (201 +/- 13 dyn X sec X cm-5). The left-ventricular stroke work index in the first group was lower with significance than that in the second, the values being 33.4 +/- 2 g X m/m2 versus 44 +/- 4.6 g X m/m2.

Acute Disease↗
PubMed1988

Effect of cholestyramine on plasma cholecystokinin and pancreatic polypeptide levels, and exocrine pancreatic secretion.

The effect of acute and long-term administration of cholestyramine, a non-absorbable bile salt binding resin, on exocrine pancreatic secretion, plasma-cholecystokinin (CCK) and plasma-pancreatic polypeptide (PP) was investigated in 10 healthy volunteers. Oral ingestion of 12 g cholestyramine augmented the stimulatory effect of a liquid test meal on plasma-CCK (3.5-fold) and plasma-PP (2-fold). During prolonged treatment with 3 x 12 g cholestyramine daily for 4 weeks, the most pronounced increase in basal hormone levels was observed after 1 day, but progressively decreased during treatment and had normalized after 4 weeks. However, the stimulated plasma-CCK output was still significantly elevated after cessation of treatment, compared with pretreatment values. After acute and chronic cholestyramine administration only stimulated lipase secretion was elevated, whereas trypsin and amylase remained unchanged. It is suggested that removal of bile salts enhances CCK and thereby PP release and pancreatic lipase secretion.

Adult↗
PubMed1988

Vagal influence on cholecystokinin and neurotensin release in conscious dogs.

Cholecystokinin (CCK) release in seven conscious dogs was investigated by means of modified sham feeding. After sham feeding mean CCK concentrations rose from a basal value of 1.0 +/- 0.2 pmol/l to a peak value of 2.4 +/- 0.3 pmol/l (p less than 0.005). The release in response to sham feeding amounted to half of that seen after normal feeding. Atropine significantly altered CCK output after sham feeding (basal, 1.0 +/- 0.2 pmol/l; peak 1.3 +/- 0.3 pmol/l). Sham feeding did not affect neurotensin release. It is concluded that an important cephalic phase of CCK release exists which seems to be dependent on a cholinergic mechanism.

Animals↗
PubMed1988

[Achievements of tumor surgery in tumors of the breast].

Radical mastectomy (Rotter-Halsted) lowered the local and regional recurrence rate from 60% to 6%. Prospective randomized trials showed that there are no differences in overall survival or disease-free survival when a combination of simple mastectomy and lymph node dissection is used; the axillary recurrence rate was 1.8%. Adjuvant radiotherapy is superfluous. Conservative therapy should be reserved for stage I carcinomas in breast cancer.

Breast Neoplasms↗
PubMed1987

Surgical treatment of pancreatic pseudocysts.

Between 1966 and 1980, 54 patients (40 men and 14 women) with a mean age of 38 years were operated on for a pancreatic pseudocyst at the Department of General Surgery, University of Göttingen. The aetiology of the cysts was alcohol abuse in 35 patients, biliary diseases in 8, blunt abdominal trauma in 4, virus-induced in 2 and unknown in 5. With the exception of those who had had trauma, all patients were suffering from chronic pancreatitis. Surgical therapy included in all cases a cystojejunostomy (52 with a Roux-Y-limb and 2 with an omega loop). The mean follow-up period was 13 years (range 6 to 20 years). The late mortality was 15 per cent (8 of 52 patients). Recurrent cysts occurred in two patients (5 per cent) and relapse of pancreatitis in one third of the patients. Deterioration of carbohydrate metabolism was observed in 20 per cent of the patients. After drainage operation stool fat content became normal in 20 per cent and deteriorated in 13 per cent. Persistence or cessation of alcohol intake influenced the long-term results. From these data we conclude that both alcohol withdrawal and sufficient drainage of the pseudocyst are important factors in the prognosis of pseudocyst.

Adult↗