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Biomedical subjects

H Sommer

Publications and source records attributed to H Sommer.

At least 181 records · Page 10Linked to original sources
PubMed1978

Immune status in Crohn's disease. I. Leukocyte and lymphocyte subpopulations in peripheral blood.

Proportions and absolute numbers of circulating leukocyte populations and lymphocyte subpopulations (T- and B-cells) were determined in 33 patients with Crohn's disease (group CD), and were compared with those of age- and sex-matched healthy subjects. Group CD comprised 15 patients with newly diagnosed, short-standing, and untreated CD (group CD 1) and 18 patients with long-standing, previously drug treated CD (group CD 2). All CD groups showed a significant absoulte leukocytosis, based on a significant absolute and relative increase of the neutrophils, and, as far as group CD and CD 1 were concerned, also of the absolute number of monocytes. In group CD 1, absolute lymphocyte and relative as well as absolute T-cell numbers were close to normal. In contrast, in group CD 2 absolute as well as relative numbers of lymphocytes and absolute numbers of T-cells were highly significantly reduced, whereas the reduction of the relative T-cell concentration barely reached significance. The proportion of B-cells was significantly above normal in all patient groups, the absolute number in group CD only. Also group CD 1 showed considerably, though statistically insignificantly, higher than normal absolute B-cell numbers. In group CD 1 , there was an inverse correlation between absolute T-cell numbers and disease activity, and between absolute lymphocyte numbers and duration of disease. These data indicate that there is no gross numerical reduction of the carriers of the cell-mediated immunity as a primary predisposing factor for CD, but that a reduction of these cells occurs in the circulation after the disease has started.

Adult↗
PubMed1978

Gastric transmural potential difference in rats fed with a retionol-free diet.

The concentration of retinol is decreased in serum after periods of stress. The incidence of stress ulcers can be reduced in experimental animals and in man by high doses of retinol. It has been postulated that the stress-induced reduction of serum retinol may be implicated as one of the factors favouring the development of stress ulcers. Functional damage to the gastric mucosa triggered off by noxious agents and particularly ulcerogenic drugs is followed by a fall of the transmural potential difference (P. D.). This observation has led us to investigate whether retinol-depleted rats display an alteration of the P.D. as a parameter of gastric mucosal dysfunction, when compared with animals optimally supplied with retinol. In this study it should not be demonstrated that the P.D. differs between optimally fed and retinol-deficient animals in spite of severe retinol depletion.

Animals↗
PubMed1978

Pancreatic exocrine function in rats with severe retinol deficiency.

Starting from the fact that extensive retinol deficiency leads to morphological pancreatic alterations, the secretion of the gland and the specific enzyme activities in the pancreatic tissue were studied in rats fed a retinol-free diet for 70 days. No clear alteration of the exogen stimulated pancreatic secretion and of the enzyme content of the gland was observed.

Amylases↗
PubMed1977

Serum ribonuclease activity in patients during parenteral nutrition, chronic hemodialysis and acute pancreatitis.

Animal experiments have shown that malnutrition and protein deficiency states, respectively are associated with elevated tissue ribonuclease (RNase, E.C. 3.1.4.22) activities. The causal intracellular alterations are unknown. Assuming that increased tissue RNase activities are reflected by serum levels, a study was made of the serum RNase activities in 10 healthy controls eating a normal diet (group I), 7 patients on long-term parenteral nutrition (group II), 13 chronic hemodialysis patients (group III), and 9 patients with acute pancreatitis (group IV). In group I the serum RNase activity corresponded to 195.3 + or -58.8 U/ml. A significant (p less than 0.005) elevation was noted in groups II (314.6 +/- 95.3 U/ml) and III (374.1 +/- 102.1 U/ml), no difference being detected in group IV (295.1 +/- 191.9 U/ml).

Acute Disease↗
PubMed1977

Study on lipid absorption in uraemia.

While the occurrence of morphological and functional small intestinal alterations in chronic uraemia is well established, analyses of intestinal lipid utilization are rare. In the present study faecal fat excretion in chronically uraemic humans and rats and the reesterification of a long-chain fatty acid in the mucosa of the small intestine of uraemic rats were investigated. -Reesterification of 14C-palmitic acid in the intestinal mucosa of rats with chronic uraemia produced by 5/6-nephrectomy (BUN 37.8 +/- 12.8 mg/100 ml, serum creatinine 3.0 +/- 0.44 mg/100 ml) was found to be significantly lower (374.2 +/- 166.8 mumol/mg protein x h) than in controls (604.9 +/- 274.2 mumol/mg protein x h) pointing to a disturbance of the intracellular process of absorption of long-chain fatty acids. However, the mean daily fat excretion in the faeces of chronically uraemic rats fed a diet with normal (4.2 per cent) or relatively high fat content (10 and 15 per cent) was not increased. In 20 patients with chronic renal insufficiency (BUN 75.9 +/- 35.9 mg/100 ml, serum creatinine 7.5 +/- 2.8 mg/100 ml) the faecal fat excretion was within the normal range (4.2 +/- 1.2 g/day). These results indicate a sufficient compensation of the impaired intestinal reesterification of fatty acids by the large functional reserve of the small intestine.

Animals↗
PubMed1976

Lac Repressor. Fluorescence of the two tryptophans.

By comparing the fluorescence emission properties of the wild type lac repressor with two lac repressors altered at tryptophan 190 and 209, respectively, we show that tryptophan residue 209 has its environment changed, either by its own motion, or that of the surrounding amino acids when an inducer molecule is bound. Substitution of this tryptophan with other amino acids results in lac respressor molecules with reduced affinity for inducer molecules, indicating that the geometry at residue 209 affects the geometry of the inducer-binding site. From the results of potassium iodide quenching of fluorescence from the tryptophans, and from attempts to react the native lac repressor with dimethyl(2-hydroxy-5-nitrobenzyl) sulfonium bromide and 2-hydroxy-5-nitrobenzyl bromide, we propose that tryptophan residue 209 is involved in a conformational change of the protein upon binding of inducer, but does not come in direct contact with inducer.

Amino Acids↗