Search PubMed⌕ Search

Biomedical subjects

C Wolf

Publications and source records attributed to C Wolf.

At least 271 records · Page 15Linked to original sources
PubMed1978

[Studies of spin-labeled spectrin].

Spectrin isolated from human erythrocytes has been spin-labeled with five maleimide nitroxides. The mobility of the labels is strongly dependent on their size, and on the temperature. A thermal transition of spectrin is shown to occur above 30 degrees C. Calcium and magnesium provoke a strong immobilization of the labels. This effect is yet more pronounced when spectrin is allowed to reassociate with the cytoplasmic surface of the membrane.

Electron Spin Resonance Spectroscopy↗
PubMed1978

Phospholipases of plasmic membranes of adipose tissue. Possible intermediaries for insulin action.

In the present investigation we have shown that cytoplasmic membranes of adipocytes contain A1 and A2 phospholipase activities which are optimal in a buffer with 5 mM Ca2+ (pH 8.5). Insulin enhances these activities within phosphatidylethanolamine. Insulin increases also the amount of free fatty acids in membranes. Rodbell and Blecher have already shown an insulin-like action of phospholipases towards the uptake of glucose and amino-acids by adipocytes. Shier and Asakawa have recently described that lysolecithin and unsaturated fatty acids can change nucleotide-cyclase activities of cytoplasmic membranes towards GTP and ATP; lysolecithins and Triton X 100 seem to react in an identical way. Results from these studies give new suggestions on insulin action; phospholipase activation changes membrane physiochemical properties inducing an increase of glucose carrier mobility and leading the membrane cyclase enzyme (s) towards GMP cyclic synthesis.

Adipose Tissue↗
PubMed1977

[Plasma bile acids fractionnation by gas-liquid chromatography : application to hepatocellular deficiency investigation (author's transl)].

The level of the four major bile acids was measured in the plasma using gas liquid chromatography. The enhancement of the level of the primary bile acids was well known during bile duct obstruction. In the case of hepatic diseases, the chenodesoxycholiccholic acid concentration ratio (CDC/C) was equal or lower than unity when cholestasis occurred rather than hepatic deficiency. When hepatic deficiency developed, the ratio CDC/C was higher than unity. Plasma bile acid fractionnation exhibits also a prognostic value. When the ratio CDC/C is very high, it is significant of progressive hepatic deficiency. A high level of lithocholic acid is also a sign of unfavourable prognosis.

Bile Acids and Salts↗
PubMed1976

[Investigation of the choleretic action of febuprol on healthy test subjects (author's transl)].

The choleretic effect of 3-butoxy-1-phenoxypropanol-(2), Febuprol (INN), was examined in healthy volunteer subjects. In a dose range from 50 to 200 mg, the total bile is dose-dependent and excretion is significantly increased. The excretion of the bile constituents bile acids, bilirubin, cholesterol and phospholipids is increased proportionally with the bile secretion. The lithogenic index remains unaltered.

Adult↗
PubMed1976

Phospholipases A1 and A2 of rat liver plasma membranes; mechanism of action.

While V/S plots of phospholipase A1 show a phase transition, kinetic behaviour of phospholipase A2 acting in the same concentration range is hyperbolic. However after phospholipase A2 has been solubilized from the plasma membranes by 1 M NaCl, the V/S curve shows a phase transition. Membrane-bound phospholipase A1 shows a narrow optimum pH at 8.5 -9, while phospholipase A2 activity presents only small variations between pH 7 and 9.5. Towards exogenous phospholipids at the optimum pH 8.5 of phospholipase A1, the specific activity of the latter is 3-fold higher than phospholipase A2 specific activity. On the contrary towards endogenous phospholipids, phospolipase A2 activity is higher than phospholipase A2 activity. Moreover labeled endogenous PE hydrolysis by phospholipase A2 is decreased by addition of non labeled exogenous PE into the incubation medium. All these data suggest that the active site of phospholipase A1 is turned to the outside and acts only on exogenous substrates: for phospholipase A2 it would be inside, and exogenous phospholipids could be hydrolyzed only after penetrating the membrane.

Animals↗
PubMed1975

[Subcellular localization of rat adipocyte lipoprotein lipase].

The sub-cellular localisation in rat fat cells of lipoprotein lipase is discussed in this paper. The lipoprotein lipase was found with maximum activity in the microsomal fraction. Some special features of this activity in membrane fraction are pointed out.

Adipose Tissue↗