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Biomedical subjects

H D Janisch

Publications and source records attributed to H D Janisch.

At least 37 records · Page 2Linked to original sources
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

The influence of two histamine H2-receptor antagonists, cimetidine and ranitidine, on the plasma levels and clinical effect of nifedipine and metoprolol.

In six healthy volunteers pharmacokinetic and pharmacodynamic interaction of metoprolol and nifedipine with cimetidine and ranitidine was investigated after 1 week of monotherapy with nifedipine and metoprolol and after 1 week each of combined treatment of these drugs with the H2-receptor antagonists. Ranitidine led to a 50% increase in mean peak plasma levels and in the area under the plasma level time curve (AUC) of metoprolol (p less than 0.05) and to an insignificant 30% rise in these parameters of nifedipine (p less than 0.05). Cimetidine increased metoprolol's peak plasma levels of AUC by about 60% (p less than 0.05) and those of nifedipine by 80% (p less than 0.05). Compared to monotherapy with metoprolol beta blocking activity measured by exercise induced tachycardia was not significantly stronger inhibited under the combined treatment of metoprolol with each of the two H2-receptor antagonists. On the other hand the antihypertensive effect of nifedipine was significantly increased during concurrent administration of cimetidine in seven hypertensive patients when compared with monotherapy.

Adult↗
PubMed1984

Daytime acid secretion after a single dose of ranitidine and cimetidine--a double blind crossover study.

The purpose of the study was to evaluate the duration of inhibition of acid secretion by single oral doses of cimetidine and ranitidine. Basal and postprandial acid secretion in 6 healthy volunteers were measured for 14h by intermittent aspiration and prolonged intragastric titration. 400 mg cimetidine reduced daytime acid secretion by 22% and 150 mg ranitidine produced 38% inhibition. Although the elimination half lives of the drugs were similar, ranitidine led to more pronounced inhibition of acid secretion during the later part of the day. The longer duration of pronounced acid inhibition by ranitidine appears to be due solely to its greater potency.

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

Drug interactions with nitrendipine.

Interactions between calcium channel blockers like nifedipine and concurrently administered drugs like digoxin or cimetidine have been described in the literature. Therefore, possible interactions of the new calcium channel blocker nitrendipine (20 mg daily) with digoxin (0.5 mg daily), digitoxin (0.1 mg daily), cimetidine (1,000 mg daily), ranitidine (300 mg daily), atenolol (100 mg daily), metoprolol (200 mg daily), and acebutolol (400 mg daily) were studied following 1 week of combined treatment of nitrendipine with each of these drugs. Six healthy volunteers were investigated (mean age, 30.2 +/- 2.1 years; mean body weight, 69.7 +/- 4.7 kg; means +/- SEM). Under nitrendipine monotherapy, maximum plasma levels (Cmax) averaged 41.6 +/- 12.8 ng/ml, and they were reached after 2 h. Mean area under the curve was 131.5 +/- 40 ng ml-1 h, and "oral" plasma clearance (Clpl) amounted to 80.8 +/- 27.5 L/h. The H2 receptor antagonists cimetidine and ranitidine and the digitalis glycosides like digoxin or digitoxin did not alter nitrendipine kinetics significantly. Also simultaneous treatment with beta-blockers did not significantly influence kinetic values of the calcium channel blocker, but atenolol showed a tendency to increase Cmax of nitrendipine to 54.2 +/- 19.7 ng/ml, when its Clpl was distinctly lowered to 42.7 +/- 10.4 L/h (p greater than 0.05 compared with 80.8 +/- 27.5 L/h under nitrendipine monotherapy). Increased digoxin plasma levels and digoxin-induced side-effects were seen under nitrendipine co-administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
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↗
PubMed1983

[Effect of cimetidine and ranitidine on the pharmacokinetics and anti-hypertensive effect of nifedipine].

Simultaneous administration of cimetidine and nifedipine to six healthy volunteers produced an about 80% rise in maximal plasma levels and the area under the plasma level-time curve of nifedipine compared with results on nifedipine administration alone (P less than 0.05). After treatment for one week with 4 X 10 mg nifedipine daily and 3 X 200 mg cimetidine daily and 400 mg at night plasma level peaks of nifedipine averaged 87.7 +/- 19.1 ng/ml, while after 4 X 10 mg nifedipine alone they were only 46.1 +/- 10.6 ng/ml. Ranitidine produced an approximately 25%, nonsignificant, rise in plasma level-time curve and peak plasma levels of nifedipine. Seven hypertensives (WHO stage I and II) had a mean arterial blood pressure level of 127 +/- 2.5 mm Hg after two-week placebo administration, and of 109 +/- 2.38 mm Hg after four weeks of nifedipine alone at 4 X 10 mg daily (P less than 0.01). After additional administration of 1 g cimetidine daily for two weeks the mean blood pressure fell significantly to 95 +/- 3.1 mm Hg (P = 0.02), while blood pressure fell to 103 +/- 3.88 mm Hg after two weeks of additional administration of 300 mg ranitidine daily, a fall which was not significant (P greater than 0.05). The interaction of nifedipine and cimetidine is thus of clinical significance because of its pharmacodynamic effect.

Adult↗
PubMed1983

Wet swallows stimulate abnormal contractions in patients with oesophageal motility disorders.

The aim of this study was to determine the effect of dry and wet swallows on oesophageal contractions in patients with oesophageal motility disorders (achalasia, diffuse oesophageal spasm and "intermediate" motility disorders). Wet swallows resulted in greater amplitude of oesophageal contractions than did dry swallows, both in patients with oesophageal motility disorders and controls. In patients with oesophageal motility disorders wet swallows were also followed by a greater incidence of repetitive contractions than dry swallows. This increased incidence of abnormal contractions correlated significantly with the increase in oesophageal baseline pressure during wet swallows. The administration of pentagastrin further increased the amplitude and duration of oesophageal contractions in patients with oesophageal motility disorders, but the incidence of abnormal contractions remained unaltered. It is concluded that wet swallows compared to dry swallows pronounce the abnormality of oesophageal contractions in patients with oesophageal motility disorders.

Adult↗
PubMed1983

[Trauma-induced thrombosis of the inferior vena cava].

A 25 year old foreign patient, in his native country had a blunt polytrauma of the abdomen and of the thigh. The consequence was a complete thrombosis of the vena cava inferior in a distal position to the junction with the liver veins. The diagnosis was realized with phlebography, angiography and computertomography. The diaphragmatic part of the vena cava inferior and the liver veins were not affected by the thrombosis. The increasing edemas of the shank and a stasis ulcer which were the reason for the patients admission to the hospital could be treated successfully by Furosemid and Phenprocoumon within a period of 4 weeks.

Abdominal Injuries↗
PubMed1983

Barrett's syndrome: correlation of oesophageal morphology with potential difference measurements.

This study was undertaken to correlate oesophageal histology with the results of potential difference measurements in patients with Barrett's syndrome. Combined manometric and potential difference measurements were performed in 10 patients with Barrett's syndrome and in 12 healthy volunteers. In addition patients with Barrett's syndrome underwent repeated endoscopy with multiple biopsies. In contrast to normal persons, patients with Barrett's syndrome exhibited the potential difference transition zone proximal to the lower oesophageal sphincter. However, compared to histologic findings potential difference measurements underestimated the extent of the pathological epithelium. These differences appear to be due to the occurrence of specialized columnar epithelium in patients with Barrett's syndrome which cannot be differentiated from oesophageal squamous epithelium by potential difference measurements. Thus, PD measurements identify the presence of Barrett's syndrome but do not allow to determine the extent of the disease.

Action Potentials↗