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Biomedical subjects

K E Hampel

Publications and source records attributed to K E Hampel.

At least 19 recordsLinked to original sources
PubMed1997

Bile acid-independent bile flow is differently regulated by glucagon and secretin in humans after orthotopic liver transplantation.

The present study characterizes recovery of bile secretion after orthotopic liver transplantation (OLT) in humans with special regard to hormonal regulation of bile acid-independent bile flow by glucagon and secretin. Sixty-seven patients with an uncomplicated postoperative course were studied during the first 3 weeks after OLT to determine normalization of bile flow. A group of 7 and 10 patients, respectively, underwent a biliary stimulation test by either glucagon at days 7, 14, and 21 after OLT or by secretin at days 2, 10, and 21 after OLT. Secretin tests were similarly performed in patients with acute severe rejection during the first 10 days after OLT, while glucagon tests were performed in patients with acute allograft rejection occurring 2 weeks after OLT. Furthermore, hormone effects were studied in nontransplanted patients after cholecystectomy with indwelling biliary T tube. After OLT, bile secretory function recovered and stabilized within 14 days after surgery by reconstitution of both bile acid-dependent and -independent bile flow. Two weeks after OLT, bile secretion was comparable with nontransplanted patients after cholecystectomy. Glucagon and secretin stimulated bile acid-independent bile flow in transplanted and nontransplanted patients significantly, yet secretin choleresis, unlike glucagon choleresis, had already occurred during the first days after OLT and was unaffected by acute allograft rejection. These results allow the speculation that, in humans, glucagon and secretin exert their choleretic activity by different mechanisms and/or at different anatomical sites in the liver. Assuming that secretin acts at the bile duct cells, its secretory capacity was not altered by the transplantation procedure and during moderate or severe rejection episodes, as opposed to glucagon choleresis, which most likely originates in the hepatocytes and requires an entirely reconstituted canalicular transport system after OLT.

Acute Disease↗
PubMed1995

Gastroesophageal reflux in patients with sleep apnea syndrome.

UNLABELLED: Gastroesophageal reflux (GER) may be associated with pulmonary diseases. The aim of this study was to investigate the role of GER in patients with sleep apnea syndrome (SAS). We evaluated, therefore, in patients with SAS the occurrence of GER during simultaneous apnea monitoring, and whether GER is related to the severity of SAS. METHODS: 17 consecutive patients with proven SAS were divided into two groups according to the severity of SAS: (A) apnea index > or = 5 and < 15, n = 8; (B) apnea index > or = 15, n = 9. All patients underwent 24 hours pH-metry in the proximal and distal esophagus and simultaneous apnea monitoring during the night. RESULTS: There was a high occurrence of GER in patients with SAS, but no significant difference was found between the two groups with respect to reflux times at the distal or at the proximal esophageal site. Reflux episodes and apnea periods were not timely correlated. Most of the patients of both groups were obese. CONCLUSIONS: Patients with SAS often have GER. However, there is neither a relation of GER with the severity of SAS nor a timely association between GER- and SAS-episodes. Thus, it is unlikely that there is a direct link between GER and SAS. However, there may be factors predisposing for both diseases.

Adult↗
PubMed1993

[Delayed stenosis after endoscopic sphincterotomy (EST)?].

To answer the question of restenosis following endoscopic sphincterotomy (EST) different and sophisticated methods were performed. Using the Erlangen type papillotome we developed a practicable and standardised method for measurement of the size of the EST that is able to define a restenosis. Depending on the indication for EST we found different percentages of restenosis: common bile-duct stones 14%, papillary stenosis 23.1%, duodenal diverticula without bile duct stones as cholestatic entity 40%. On one hand reduction of EST size is not corresponding to clinical symptoms, on the other hand the symptoms of patients after EST with sufficient EST size have to explained in other ways such as gall bladder still existing. Due to these experiences in patients with symptoms following EST we propose a control ERC combined with mechanical measurement of the sphincterotomy size.

Adult↗
PubMed1990

[Metoclopramide antagonizes dopamine-induced inhibition of lower esophageal sphincter pressure in the awake beagle].

Different contradictory results, even in the same species of the DOP-effect on LESP have been reported. The aim of the present studies was to evaluate the effect of DOP on LES in purebread male beagles and whether in could be antagonised by the DOP-antagonist MCP. The LESP in beagles is sensitive to dopamine (DOP) and its "antagonist", metoclopramide (MCP). MCP raised the inhibited LESP after DOP-infusion in vivo, while it failed to change DOP-induced relaxation of opossum LES in vitro [1]. Data obtained after monotherapie with MCP did not exceed LESP-response to MCP after DOP-pretreatment. DOP applied as background counter-inhibition could be used to correct interdigestive phasic changements of LESP in order to reach a stable starting-point to investigate the action of LESP-stimulating compounds pharmacomanometrically. Due to DOP reflux-facilitating side effect via its decrease of LESP, large doses of DOP, as used in the intensiv care unit, should be administered together with sphincter-strengthening agents or antacid compounds.

Animals↗
PubMed1989

[Determination of gastric bicarbonate secretion in the human without acid suppression].

Gastric CO2/HCO3 was determined in absence of simultaneous inhibition of acid secretion by intra- and extragastric pCO2/pH measurements in 23 persons and calculated using the equation of Henderson-Hasselbalch. pCO2 was measured with use of a new electrode. The characteristics of the CO2 selective electrode membrane were tested in vitro. The CO2 selective membrane proved to be stable against 0.1 n HCl, gastric fluid with a pH of 1, and bile as well as mechanical irritations. 96.8 +/- 0.52% of given amounts of bicarbonate were detected in test fluids ranging in pH from 2.5-7.1. In gas and fluid, a linear relationship between given and measured bicarbonate of y = 0.97 x +1.03 with a correlation coefficient of 0.99 was observed. In vivo at pH less than 6, the intragastric pCO2 was significantly higher than that in venous blood. CO2 diffusion could be prevented by equilibration of intragastric pCO2 with venous pCO2. pCO2 was then measured in fluid as well as in reaspirated gas. Thus 94.6 +/- 8.8%, HCO3- that had been instilled intragastrically, could be detected. Without equilibration and resultant volume increase of the gas phase, bicarbonate secretion was 296.4 +/- 41.9 mumol/h under basal conditions and 520.8 +/- 252.8 mumol/h after acid stimulation. With equilibration, a bicarbonate secretion of 574.4 +/- 66.7 and 754.4 +/- 81.2 mumol/h was observed during basal and stimulated acid secretion. Our results indicate that bicarbonate measurements in absence of acid suppression require determination of CO2 in the fluid as well as in the gas phase.

Bicarbonates↗
PubMed1989

[The diagnostic value of serum PABA determination in pancreatic disease and in relation to anticholinergic medication].

PABA-serum and urine-concentration were studied in patients with normal, pathologic and pharmacologically inhibited pancreatic function. Secretin-pancreozymine test was selected as reference method. In patients with normal pancreas function and volunteers, PABA-serum-concentration was characterized by a rapid increase during the first 1 1/2 hours. A maximum increase of 32.42 +/- 10.04 mumol/l was reached after 90 minutes. In patients with exocrine pancrease insufficiency, difference to the control group was greatest after 30, 60, 90, and 120 min. Pharmacologic inhibition of the exocrine pancreas using pirenzepine also resulted in a significantly reduced PABA-serum-concentration after 30, 60 and 90 min. In correspondence to the delayed and smaller serum PABA increase, urine-PABA-concentrations were also diminished. Our results indicate that the optimal interval to differentiate between normal and impaired pancreas function with use of serum PABA determination is at 90 min after test begin.

4-Aminobenzoic Acid↗
PubMed1988

[Various effects of secretin and pentagastrin on peripheral venous blood gas analysis].

Until recently, vasomotor effects of gastrointestinal polypeptide hormones have been observed primarily in animal experimentation. 33 volunteers were observed to survey the influence of secretin (1 CU/bw./h) and pentagastrin (0.75 micrograms/bw/h) on peripheral blood gas concentrations and on the acid/base balance. Compared to a control group, secretin caused a significant increase in pO2 and in O2 saturation (p less than 0.05). In contrast to secretin, pentagastrin caused a significant decrease in the pO2 as well as in the O2 saturation (p less than 0.05) pCO2, pH and HCO3 were not significantly affected by either secretin or pentagastrin. These results can be interpreted as possible direct vasodilatative/constrictive as well as local metabolic effects of secretin and pentagastrin.

Adult↗
PubMed1986

Changes in the blood gas concentration caused by secretin and cholecystokinin. Indication of a vasomotor effect?

The assumption that secretin has a general vascular effect led to an investigation of the blood gas level in the peripheral veins and the acid/base balance under the influence of secretin (1 CU/kg/h, 0-120 min) and cholecystokinin (CCK) (1 IU/kg/h, 60-120 min) in a group of 10 volunteers. Six of the volunteers were subjected to a randomized, cross-over NaCl infusion study. With a secretin infusion alone (0-60 min) there was a transient, significant rise in PO2 (p less than 0.01) and oxygen saturation (p less than 0.05), which was no longer detectable after 60 min (p greater than 0.05). With an additional administration of CCK (60-120 min) and in the follow-up phase of observation (120-180 min) there was a significant fall in both parameters (120 min: p less than 0.05, 180 min: p less than 0.01). PCO2, HCO-3, and pH remained unaffected. The isolated increase in PO2 and O2 saturation may be attributed to vasodilation induced by secretin. The drop in both parameters under the influence of an additional infusion of CCK and in the follow-up phase of observation is linked to a possible vascular effect of CCK.

Adult↗
PubMed1985

[Absence of effect of secretin and cholecystokinin on plasma concentrations of vasoactive intestinal polypeptide and pancreatic glucagon].

There is little information about the effect of peptides on the VIPergic system. Reports of the influence of secretin and cholecystokinin (CCK) on pancreatic alpha cells are contradictory. With the help of volunteers we investigated the influence of a new synthetic secretin (1 CU/kg/h, 0 to 120 min) alone and in combination with GIH-CCK (1 IU/kg/h, 60 to 120 min) on the concentrations of VIP (n = 13), pancreatic glucagon (PG) (n = 15) and blood sugar (n = 10). 6 of the volunteers were subjected to a randomized cross-over NaCl infusion study. Neither secretin (0 to 60 min) nor secretin and CCK (60 to 120 min) infusion caused a significant change in VIP (31 +/- 3 vs. 34 +/- 4.5 pg/ml, mean +/- SEM, p greater than 0.05), PG (102 +/- 9 vs. 116 +/- 12 vs. 114 +/- 12 pg/ml, p greater than 0.05) or blood sugar (about 90 mg/dl) concentrations. There is no evidence of an influence of secretin and CCK on te VIPergic system and the pancreatic alpha cells.

Adolescent↗
PubMed1985

[Indication of the vasomotor effects of secretin and cholecystokinin by changes in blood gas concentration?].

The assumption that secretin has a general vascular effect led to an investigation of the blood gas level in the peripheral veins and the acid/base balance under the influence of secretin (1 CU/Kg/h, 0 to 120 mins) and cholecystokinin (1 IU/Kg/h, 60 to 120 mins) in a group of 10 volunteers. Six of the volunteers were subjected to a randomised crossover study under NaCl infusion. With a secretin infusion alone (0 to 60 mins) there was a transient, significant rise in PO2 (p less than 0.01) and oxygen saturation (p less than 0.05), which was no longer detectable after 60 minutes (p greater than 0.05). With an additional administration of cholecystokinin (60 to 120 mins) and in the follow-up phase of observation (120 to 180 mins) there was a significant fall in both parameters (120 min.: p less than 0.05, 180 min.: p less than 0.01). PCO2, HCO-3 and pH remained unaffected. The isolated increase in PO2 and O2 saturation may be attributed to vasodilation induced by secretin. The drop in both parameters under the influence of an additional infusion of cholecystokinin and in the follow-up phase of observation is linked to a possible vascular effect of cholecystokinin.

Acid-Base Equilibrium↗
PubMed1984

[Effect of synthetic secretin and GIH-cholecystokinin on serum gastrin levels].

In response to the report of a false-positive increase in serum gastrin with the use of natural secretin (Boots), 11 test persons were enlisted in order to examine the effect of a new synthetic secretin (Hoechst), both alone and in combination with natural CCK, on serum gastrin concentration. 6 of the test persons were subjected to a randomised cross-over study under NaCl infusion. Under secretin (0 to 60 minutes) there was a significant fall in gastrin from 32 +/- 2.3 pg/ml to 23 +/- 2 pg/ml (p less than 0.01). When CCK was also administered (60 to 120 minutes) the gastrin level increased to 46 +/- 3.5 pg/ml (75 versus 0 minutes: p less than 0.01), 75 versus 60 minutes: p less than 0.001). At the end of the infusion the gastrin level had fallen significantly once more to 21 +/- 2 pg/ml (135 versus 120 minutes: p less than 0.001, 135 versus 0 minutes: p less than 0.01). On the basis of in vitro studies -- which revealed a cross-reaction of 2.4% - the increase in gastrin under CCK is not regarded as being due to cross-reaction with CCK but rather to contamination by other peptides.

Adult↗
PubMed1984

[Endoscopy of the upper gastrointestinal tract: changes in the concentration of vasoactive intestinal polypeptide and gastrin?].

The report of a significant increase in plasma VIP concentration (PVC) during endoscopy of the upper gastrointestinal tract prompted us to examine this question under comparable experimental conditions, with simultaneous determination of serum gastrin concentration (SGC). Thirteen patients took part in a study wherein PVC and SGC were determined before, during and after oesophagogastroduodenoscopy (OGD). Before OGD the value for PVC was 30 +/- 2.5 pg/ml (means +/- SEM); during endoscopy it tended to increase slightly, to 35 +/- 3.2 pg/ml immediately after the examination (p greater than 0.05). By contrast with this finding, the SGC increased rapidly and significantly from 47 +/- 4.7 pg/ml prior to the examination to maximal values up to 68 +/- 6 pg/ml on inspection of the fundus (p less than 0,005), and was at a significantly increased level (p less than 0.05), with a value of 61.5 +/- 7.2 pg/ml, as much as thirty minutes after the examination. Sixty minutes after the examination the values had fallen to their original level (47.5 +/- 7.5 pg/ml). The present study shows that OGD has no significant influence on PVC, but that it is possible that stimulation of the VIP-ergic system is accompanied by a trivial increase in PVC. By contrast with this OGD significantly increases the concentration of endocrinally secreted gastrin, an effect which lasts as much as thirty minutes after the examination. The release of gastrin is a result of the combined effect of mechanical stimulation, distension due to insufflation of air and simultaneously induced neural influences. However, these mechanisms exert at most an insignificant influence on PVC - if indeed they have any effect on it at all.

Adult↗
PubMed1984

Is abdominal compression a useful stimulation test for analysis of lower esophageal sphincter function?

The change in pressure of competent and incompetent lower esophageal sphincter (LES) due to abdominal compression is still a controversial subject. Therefore, we studied the effect of sustained (SAC) and intermittent (IAC) abdominal compression on lower esophageal sphincter pressure (LESP) in normals (N), patients with hiatus hernia (HH), and patients with scleroderma (S). When resting lower esophageal sphincter pressure exceeded 15 mm Hg, response to SAC and IAC was similar in patients with HH and in normals. On the other hand when basal LESP was below 15 mm Hg, stimulated sphincter pressure during IAC was significantly lower than during SAC. Values recorded during SAC were also falsely high in patients with scleroderma. Values obtained during either SAC or IAC did not depend on presence or absence of reflux symptoms in any group. LES stimulation with IAC gives valid results which correlate closely with LESP. Stress tests with IAC therefore seem to be a useful stimulation test for the analysis of LES function.

Abdomen↗
PubMed1984

[Radioimmunological determination of plasma VIP and serum gastrin concentrations as affected by nutrition].

In 10 volunteers, the plasma VIP and serum gastrin concentrations before and after a test meal were measured at thirty minute intervals over a period of 5 hours. The precision of the VIP radioimmunoassay (double antibody method) is indicated by a coefficient of variation of 6%; its accuracy is reflected by the percentage deviation in the dilution test of between 0.6 and 8.5%. There was no significant difference in VIP concentrations before and after consumption of the test meal (p less than 0.05), WILCOXON test). In contrast, the gastrin concentration had already risen significantly (p less than 0.01) after thirty minutes. It then dropped back to the fasting range over a period of 5 hours. The lack of a rise in VIP after ingestion of the test meal supports the contention that VIP is purely a neurotransmitter. In contrast, the test meal induced a luminal stimulation of G-cells with endocrine secretion.

Adult↗
PubMed1984

[Secretin and cholecystokinin: hormonal action on the concentration of vasoactive intestinal polypeptide and gastrin in human subjects?].

There is little, and partially contradictory information about the mutual hormonal effects of peptides. With the help of volunteers we investigated the influence of a new synthetic secretin (1 CU/kg/h, 0 to 120 min.) alone and in combination with GIH-CCK (1 IU/kg/h, 60 to 120 min.) on the concentration of VIP (n = 13) and gastrin (n = 20). Six of the volunteers were subjected to a randomized cross-over study under NaCl infusion in which both peptides were determined. The VIP concentration was not significantly influenced (31 +/- 3 - 34 +/- 4 - 38 +/- 4.5 pg/ml, p greater than 0.05) by either secretin (0 to 60 min.) or by secretin and CCK (60 to 120 min.). In contrast, secretin induced a significant fall in the gastrin level (30 +/- 2 vs. 24 +/- 2 pg/ml, p less than 0.05). With an additional administration of CCK there was a significant rise in gastrin (75 min.: 46 +/- 3 pg/ml, p less than 0.005) with a decline in peptide levels at the end of the infusion (135 min.: 23 +/- 2 pg/ml, p less than 0.005). The cross reactivity with GIH-CCK and CCK-octapeptide was 2.4 and 3% respectively. The increase in gastrin is not regarded as being due to cross reaction with CCK. This may be due to either contamination of the CCK preparation by other peptides which exert an influence on the gastrin level or the CCK induced release of bile.

Adolescent↗
PubMed1984

Histologic abnormalities in routine biopsies of patients with esophagitis and different gastric acid secretion.

Intraepithelial eosinophilic granulocytes were previously reported to evidence prolonged acid reflux in patients with reflux esophagitis. The following study was performed to investigate whether or not these histologic abnormalities are specific to patients with esophagitis and high H+ ion activity of the gastric juice. Esophagitis was proved endoscopically in all patients. Biopsy specimens were obtained during endoscopy by forceps biopsy from the area involved. Afterwards an acid secretion test to determine basal and pentagastrin-stimulated H+ ion activity and a Bernstein test were performed. Histologic findings were correlated with the results of the acid secretion test. In this study, the occurrence of intraepithelial eosinophils was similar in patients with high and with low gastric acid output, but was overall low in these patients and has not proved to be a specific diagnostic criterion for reflux.

Adult↗