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Biomedical subjects

F Halter

Publications and source records attributed to F Halter.

At least 91 records · Page 5Linked to original sources
PubMed1978

[Indications for and dangers of methods for gastroenterological endoscopy].

The value of modern fiberoptic endoscopy is discussed by comparing negative and positive aspects of both radiology and endoscopy. A detailed analysis is provided of the complications observed in 16,477 invasive gastrointestinal investigations performed over the last 11 1/2 years in our unit. The morbidity was 0.1% in 5886 large bowel examinations and 0.2% in esophago-gastroduodenoscopy and in all 2871 investigations involving invasive liver-pancreas diagnostics. The overall mortality was 0.06%. It is emphasized that in invasive gastrointestinal examinations elderly and debilitated patients are at risk, whereas the danger is minimal for patients in reasonable health.

Aged↗
PubMed1978

A comparison between intragastric titration and aspiration technique under basal conditions and after food or pentagastrin stimulation.

A total of 16 healthy subjects had gastric secretory studies where acid was either measured by the conventional aspiration technique (AT) or by intragastric titration at a pH of 5.0 (IT). In a first study food- and pentagastrin-stimulated PAO levels, both measured by IT, were within similar ranges. However, as compared to the respective AT data of the same subjects, the mean IT results were 35% higher, although both values were well correlated. In a second study a similar difference was observed between IT and AT data throughout the whole range of the pentagastrin dose-response curve. Both curves followed Michaelis-Menten kinetics and had similar Km values, while Vmax values were significantly higher at IT. This constellation excludes an increase of the gastrin sensitivity of the parietal cells as a cause for the higher IT data. It is, however, in keeping with the hypothesis that the distension stimulus present at IT potentiates the pentagastrin-stimulated acid secretion. It is likely that methodological problems such as overtitration of acid at IT and transpyloric loss of acid at AT additively contribute to the relatively large difference between AT and IT values. It is therefore not possible to fully interchange AT and IT data, despite their good correlation.

Adult↗
PubMed1978

The endogenous release of pancreatic polypeptide by acid and meal in dogs. Effect of somatostatin.

The response of pancreatic polypeptide (PP) to testmeal (5 ml/kg) and intraduodenal acid (4 mEq HCl/5min) and its reaction to somatostatin (3.5 microgram/kg/h following bolus injection of 3.5 microgram/kg) was studied in dogs with chronic duodenal and gastric fistulae. In addition the influence of atropin (0.5 mg/kg/h) on acid-induced PP response was examined. PP was measured by radioimmunoassay pancreatic secretion by determinating volume, bicarbonate, protein, and enzyme in duodenal contents and pancreatic juice. Plasma PP increased significantly following intraduodenal application of testmeal and hydrochloric acid. Its release was completely suppressed by SST. Furthermore, PP response to intraduodenal acid was blocked by atropin. Exocrine pancreatic secretion of bicarbonate and protein was inhibited by somatostatin as well as atropin. Since PP was released following administration of testmeal and acid, both potent stimulators of pancreatotropic duodenal hormones, it may play an important role in the control of the entero-pancreatic axis. The effect of atropin indicates a cholinergic nervous component of PP release.

Amylases↗
PubMed1977

Intragastric titration of acid in the perfused rat stomach preparation following parenteral and intraluminal stimulation.

The anaesthetised rat stomach preparation was adapted to assay intraluminally administered stimulants and inhibitors of acid secretion by continuously recirculating the perfusate (15 ml of 5% glucose) and measuring acid by the pH-stat technique. The responses obtained were linear. Continuous artificial neutralisation of the stomach to pH 5.5 as well as variation of the pH between 6.5 and 4.0 did not significantly alter the sensitivity of the preparation to intravenously administered human gastrin-heptadecapeptide I (HG I). Basal acid secretion however significantly declined following stepwise lowering of the intragastric pH between 6.5 and 4.0. The threshold values for responses to i.v. HG I were below 16 ng. 6 doses could be given per rat without tachyphylaxis. Acetylcholine, 1.3, 2.5, 5.2 and 10.4 micron g/ml in the perfusate, induced a dose-dependent linear (r=0.902) acid secretion. Metiamide 1.66 mg/ml in the perfusate, produced a parallel shift to the right of the HG I dose--response curve producing an agonist dose ratio of 3.66. The data suggest that intragastrically applied stimulants and inhibitors of acid secretion can be studied precisely in this relatively simple preparation.

Acetylcholine↗
PubMed1977

Diagnostic value of biopsy, guided lavage, and brush cytology in esophagogastroscopy.

In a prospective study 96 patients with esophageal and gastric lesions were investigated by multiple endoscopic biopsy, brush cytology, and guided lavage cytology. The aim was to evaluate the diagnostic accuracy of each of these methods in a prospective study. 50 malignant and 46 benign lesions were found. The final diagnosis was proven by operation or autopsy in 53 cases, by multiple endoscopic follow-up in 31, and by clinical control in 8. No follow-up was possible in 4 patients. The malignant lesions were diagnosed by multilple biopsy in 86.0%, by brush cytology in 84.0%, and by lavage cytology in 50.0%. The diagnostic yield of lavage cytology was thus significantly lower (P less than 0.01). It is concluded that a combination of multiple biopsy and brush cytology is the most valuable aid in endoscopic diagnisis of esophageal and gastric malignancy with a diagnostic accuracy of 96%.

Adolescent↗
PubMed1977

Gastric and duodenal ulcer healing under placebo treatment.

The healing time relation of 30 gastric and 15 duodenal ulcers was assessed by repeated endoscopic measurements of ulcer size on days 1, 21, and 42 of a 6-week period, during which a selected population of patients was being treated as outpatients on an inert placebo. Antacids in small amounts were only given in case of ulcer pain. There was evidence for a linear relationship between the absolute initial ulcer size and its reduction with the time in incompletely healed ulcers of both types. Their percentage reduction from the original size was 71% after 3 weeks in gastric and 83% in duodenal ulcers; 82% after 6 weeks in gastric and 83% in duodenal ulcers. The healing time course for both types of ulcers appeared to follow an exponential function. The calculated half-life was 1.7 weeks for gastric and 1.9 weeks for duodenal ulcers. The number of healed duodenal ulcers observed at the 3-week examination was significantly greater than that of healed gastric ulcers (P = 0.05). It is concluded that repeated measurements of the ulcer size before complete ulcer healing contribute to a optimal characterization of the healing time course. The calculated half-life of less than 2 weeks makes shorter control intervals reasonable for both types of ulcers. The ulcer half-life appears to be a more accurate criterion of the healing process than that of complete healing.

Adolescent↗
PubMed1976

The development of a reliable and sensitive bioassay for gastrin in body fluids.

The sensitivity and reliability of the Ghosh and Schild rat stomach preparation was improved by implantation of bulky intragastric cannulae, recirculation of the perfusate and measurement of conductivity instead of pH. With these procedures, the threshold values for gastrin I were in the range of 1-2 ng. In attempts to increase the sensitivity further it was shown that neither vagotomy nor antrectomy influenced the sensitivity of the method. The threshold values were not lowered by attempts to reduce gastrin metabolism through nephroligature or small bowel resection. Although rats fitted with portacaval shunts did raise the threshold, the limited increase in sensitivity was also achieved by selecting the rats that gave an initially high response to a test dose of gastrin thus avoiding the complicated shunt operation. The assay procedure enabled statistically valid measurements of gastrin in plasma and from tumour extracts from patients suffering from the Zollinger-Ellison Syndrome to be assayed using a 2 + 2 block design.

Analysis of Variance↗