[On adaptation of adolescents to the vocational training in the point of view of schooldoctors (author's transl)]

Since 1969 bibliographie informes that growing numbers of apprentices and young workers are absent from work in spite of their obviously good health-state. All reported results of several studies and investigation-programms show that in most of the described cases problems of juvenile adaptability are linked with. Difficulties arise when young people change over from school education to vocational training. At first the paper deals with the differently used terminus adaptation. Three empirical principles from available studies may be deduced. They are interpreted under the point of view of school-doctors, works-doctors and vocational-school-instructors. Recommendations for school-doctors finish the paper.

Effect of nutrition on subcellular localization of rat fat-cell lipoprotein lipase

This study supports the possibility for multiple subcellular forms of lipoprotein lipase. 1. The total activity of lipoprotein lipase per g of intact epididymal adipose tissue from fed rats is much higher than that from starved rats. 2. The isolated fat-cells of fed and of starved rats have lipoprotein lipase of almost the same activity per g of fat-pads. The isolated fat-cells of starved rats have a much higher proportion of total activity per g of the intact tissue than do those of fed rats. 3. Under the conditions of homogenization used, only a small proportion of the total activity per g of intact tissue from fed rats was associated with the fat layer which floated to the top of the homogenate during low-speed centrifugation. The different proportions of the specific enzyme activity found in each subcellular fraction are described. 4. Lipoprotein lipase from plasma membranes and microsomal fractions from starved and fed rats was purified by affinity chromatography. 5. The total activity of microsomal lipoprotein lipase per g of intact adipose tissue is enhanced by a normal diet. 6. In intact epididymal adipose tissue from fed rats, the activity per g of tissue of lipoprotein lipase of plasma membranes is much higher than that in the same fraction from starved rats. By contrast, the activities per g of tissue in plasma membranes obtained from starved or from fed rats by collagenase treatment were similar.

[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.

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.

[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.

[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.

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.

Organogenic Elements and Compounds in Surface Samples from the Sea of Tranquillity

Organogenic elements, mainly carbon, nitrogen, phosphorus, and sulfur are present in the particulate material and in a breccia rock from Tranquillity Base in amounts ranging from 5 to 4200 parts per million. The major compounds of carbon released by heating are carbon monoxide and carbon dioxide; the former predominates. Small amounts of other compounds of carbon have also been observed. Sulfur can be released as hydrogen sulfide by treatment with acid. The carbon isotopic delta(13L)C values are definitely nonterrestrial (+ 13 to + 18.5 per mil).