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Biomedical subjects

S Domschke

Publications and source records attributed to S Domschke.

At least 55 records · Page 3Linked to original sources

Pancreatic juice protein associated with chronic pancreatitis and adenocarcinoma of the pancreas.

125I-protein-radioiodinated pure pancreatic juice samples from patients with adenocarcinoma of the pancreas, chronic pancreatitis, or intact pancreas were analysed by high-resolution SDS-polyacrylamide gel electrophoresis and subsequent autoradiography. Experiments resulted in the detection of a 180K protein, probably a glycoprotein, in the pure pancreatic juice from pancreatic carcinoma (93%) and chronic pancreatitis (73%) patients, which was completely absent from pancreatic juice from intact pancreas. Sephadex G-200-isolated 180K protein was found to be different from carcinoembryonic antigen (CEA) when traced by a commercial CEA radioimmunoassay, but it seemed identical in pancreatic juice samples from patients with pancreatic carcinoma and chronic pancreatitis, at least with regard to isoelectric point. In brief, the present results suggest that 180K protein identification in pancreatic juice permits adenocarcinoma of the pancreas and chronic pancreatitis to be differentiated from normal conditions but that distinction between pancreatic carcinoma and chronic pancreatitis is unlikely.

Adenocarcinoma↗

Measurement of gut hormonal peptides in biopsies from human stomach and proximal small intestine.

Using sensitive and specific radioimmunoassays, concentrations of hormonal peptides have been measured in small biopsies taken from the human stomach, duodenum, and proximal jejunum. Comparison is made of these hormone concentrations and the number of respective endocrine cells present determined by quantitative immunocytochemistry. Immunoreactive somatostatin, VIP, motilin, and gastrin were detected in all regions examined, whereas secretin and GIP were undetectable in antral extracts. Enteroglucagon-like immunoreactivity was present only at and beyond the ligament of Treitz, although a few enteroglucagon-producing cells were shown by immunocytochemistry in the duodenum. The variation of hormone concentration was found to be small in these biopsies of normal tissue within each region of the gut examined, indicating that representative hormone concentrations may be reliably obtained from small biopsy tissues. An attempt has been made to establish reference values for gut hormone concentrations in such biopsies; this may allow future study of any changes in concentration that may occur in pathological conditions.

Adult↗

Partial prevention of ethanol damage of human gastroduodenal mucosa by prostaglandin E2 in vitro.

Biopsies were taken endoscopically from the fundic, antral, and upper duodenal region of healthy volunteers and gastric ulcer patients and were incubated in carbogen-saturated and buffered Medium 199 at 37 degrees C. The rate of DNA synthesis, estimated as incorporation of tritiated thymidine into tissue DNA, was determined as an index of cellular integrity. During the 30-min incubation, ethanol (25% v/v) significantly (p less than 0.01) depressed DNA synthesis by about 50% in the gastroduodenal mucosa of normal subjects and even by two thirds in the gastric mucosa of gastric ulcer patients. Prostaglandin E2 (PGE2) by itself (1 mg/50 ml) had no stimulatory effect on DNA synthesis; it did, however, reduce the drastic fall in DNA synthesis due to ethanol (p less than 0.005) when administered concomitantly. The basic process underlying cytoprotection by PGE2 in vitro remains to be elucidated. Some indirect mechanisms, such as stimulation of gastric mucosal blood flow, are ruled out by these experiments.

Adult↗

[Lead poisoning - also today still current].

Even today lead intoxication may occasionally occur. As shown in this case report, careful history including that of the occupational environment may cause suspicion, when complaints such as abdominal pain and constipation are associated with erythrogenic disturbances due to inhibition of certain enzymes of hem synthesis. Although changes in peripheral blood and bone marrow may be typical, lead intoxication can definitely be diagnosed only by determination of lead in blood and urine, of accumulated porphyrins in the red blood cells and of the typical pattern of hem precursors in the urine. Finally, this report deals with the therapy of lead intoxication.

Adult↗

[Drug testing today].

According to the new West German drug legislation, new drugs will only be registered if their quality, effectiveness and safety is ensured. Safety means a favourable ratio of therapeutic value and risk of side-effects. Effectiveness can usually be verified most objectively in adequate and well-controlled clinical investigations (phase II and phase III of drug evaluation), which are preceded by pharmacological and toxicological experiments in animals and preliminary pharmakokinetic and pharmakodynamic studies in volunteers (phase I). In phase III and IV, rare but important adverse drug effects are looked for.

Animals↗

[Coeliac sprue and gut hormones: pathophysiological and clinical aspects (author's transl)].

In adult coeliac sprue patients, intraduodenal instillation of a hypertonic glucose-citric acid solution may release gastrointestinal hormones of the proximal (secretin, gastric inhibitory polypeptide, motilin) and distal (enteroglucagon, neurotensin) small intestine and, indirectly, of the pancreas (glucagon, insulin, pancreatic polypeptide). Characteristic plasma hormone profiles can be measured radioimmunologically. The reduced secretin response reflects most sensitively the impaired function of the small intestine. Exposure of the distal small bowel to greater nutrient loads leads to markedly and constantly elevated plasma levels of enteroglucagon. Only after complete functional as well as morphologic mucosal restoration, the increased enteroglucagon concentrations return to normal. On the other hand, the neurotensin response, which is likewise enhanced in active coeliac sprue, is sooner corrected during treatment. Gastrointestinal hormones with predominantly neurocrine action, such as vasoactive intestinal peptide (VIP), are apparently less affected by coeliac sprue. Pancreatic hormones are involved in the pathophysiology of sprue only indirectly, e. g. via diminished glucose absorption.

Adult↗

Furan H2-antagonist ranitidine inhibits pentagastrin-stimulated gastric secretion stronger than cimetidine.

In each of 7 healthy volunteers, the new furan H2-antagonist ranitidine (0.125, 0.25, 0.5, and 1.0 mg . kg-1 . hr-1) or the imidazole derivative cimetidine or normal saline were intravenously infused in the midhour of a 3-hr pentagastrin period (1.5 micrograms . kg-1 . hr-1 i.v.). With increasing doses of ranitidine, gastric acid secretion dropped dose dependently: 62, 78, 89, and 94%, respectively (P < 0.05 for all doses). A cimetidine dose of 0.82 mg . kg-1 . hr-1 (2.8 mumol . kg-1 . hr-1), equivalent to the highest ranitidine dose, led to a similar reduction of acid output (54%) as an eightfold smaller ranitidine dose. Apparently in human gastric mucosa, recognition of H2-receptors is not exclusively determined by the imidazole ring. Strong inhibitory efficacy of ranitidine was also reflected by the low calculated mean ID50 of 54 micrograms (0.15 mumol) . kg-1 . hr-1 and the IC50 of 36 ng/ml (0.1 microM). Acid inhibition by ranitidine involved both reduction in volume and acidity. The lowering effect on pepsin output was less pronounced though significant. Secretion of free N-acetylneuraminic acid and N-acetylneuraminic acid bound to glycoproteins did not change after H2-blocker administration indicating an unimpaired mucus secretion. In these short-term experiments, there were no obvious side effects or alterations in routine laboratory parameters including serum gastrin and prolactin attributable to either drug.

Adult↗