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Biomedical subjects

H Sommer

Publications and source records attributed to H Sommer.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1976

[Measurement of exhaust gases of cars in the neighbourhood of roads (author's transl)].

Air samples were collected in plastic bags simultaneously at various measuring points in the close range of streets. When examining the various bag materials, Teflon bags showed the smallest deviations in direct analyses and in analyses of up to two hours after the drawing of samples. The following methods were used for the analysis of the air samples collected in the bags: coulometry for CO and SO2, chemiluminescence for NO/NO2, chromotropic acid for CH2O and flame ionization for hydrocarbon. The various components were measured close to a highway and near streets in residential and business areas.

Air Pollution↗
PubMedDate not supplied

[Air pollution in the vicinity of streets].

Air samples were collected in plastic bags simultaneously at various measuring points in the close range of streets. When examining the various bag materials, Teflon bags showed the smallest deviations in direct analyses and in analyses of up to two hours after the drawing of samples. The following methods were used for the analysis of the air samples collected in the bags: coulometry for CO and SO2, chemiluminescence for NO/NO2, chromotrophic acid for CH2O and flame ionization for hydrocarbons. The various components were measured close to a highway and near streets in residential and business areas. The simultaneously drawn samples showed a marked dependence on traffic frequency, type of built-up area along the streets as well as meteorological conditions. An opinion survey among adjacent residents on annoyance caused by air pollution and noise resulted in distinct differences between the sections with different traffic intensity.

Air Pollutants↗