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Biomedical subjects

A Weber

Publications and source records attributed to A Weber.

At least 577 records · Page 32Linked to original sources

[Liver deiodinase activity in rats after high and low fat iodine deficient diets].

Male Wistar rats were restricted on iodine intake by feeding pure diets, without iodine addition. The high fat diet contained 50% fat (HFD), the low fat diet 3% fat (LFD). Control animals received the same diets, but with iodine addition. After feeding the diets for 7 or 19 weeks liver deiodinase activity was estimated. The iodine deficient animals showed a diminished enzyme activity in both diet groups. But after feeding the diet without iodine addition for 7 weeks the deiodinase activity significantly decreased in the HFD-group only in relation to liver weight per 100 g body weight. After 19 weeks the liver deiodinase activity in the HFD-group was diminished significantly, but the decrease was much smaller than in the LFD-group. The estimation of relative thyroid weight and iodoamino acid distribution demonstrate that the level of iodine deficiency was in iodine restricted HFD-rats greater than in appropriate LFD-rats. This result was verified by investigations of thyroidal radio iodine uptake and iodine content, PB131I, serum iodine and T4 levels in both diet groups. The reason for the lower decrease of deiodinase activity at higher iodine deficiency in HFD-rats as compared to LFD-rats and the possible importance of food enriched with fat in endemic goiter areas is discussed.

Animals↗

One-hour blood-xylose test in diagnosis of cow's milk protein intolerance.

In this prospective study, 18 consecutive children suspected of cow's milk protein intolerance (C.M.P.I.) on clinical grounds were investigated before and after challenge with cow's milk. One-hour blood-xylose, serum-IgE, eosinophil count, serum-complement (C3) and a jejunal biopsy specimen for histology and disaccharidase activity were obtained from all patients before challenge. Serum-complement was measured again 24 h after the beginning of the challenge and the first three tests were repeated on the fifth day. A second jejunal biopsy was obtained in 9 of the first 10 children. 15 of the 18 children were considered to have C.M.P.I. The one-hour blood-xylose test emerged as a simple and valuable test in the diagnosis of C.M.P.I. A significant drop (51--81%) in the one-hour blood-xylose level was observed in all 15 patients. In all patients but one it dropped below 25 mg/dl. Mean value (+/- S.D.) for the group was 47.5 +/- 11.1 mg/dl before and 17.2 +/- 4.2 mg/dl after cow's milk ingestion.

Animals↗

Modifications of aldolase during in vivo aging of rabbit red cells.

Crude hemolysates, partially purified aldolase and aldolase purified to homogeneity from reticulocytes and mature erythrocytes, were incubated with a specific antiserum raised against crystalline rabbit muscle aldolase. We show that the same aldolasic activity corresponds to a greater amount of antigen in older than in younger cells, in crude hemolysates as well as in the above mentioned preparations; that is to say, old-cell aldolase contains cross-reacting material (CRM). Properties of purified enzyme from reticulocytes and mature erythrocytes were compared to those of muscle crystalline aldolase: -- the molecular specific activity of purified aldolase from erythrocytes is lower than with crystalline muscle aldolase, i.e. CRM is maintained throughout the purification steps. -- the specific activity of red cell aldolase towards both substrates (FDP and F1P) is lower than that of crystalline muscle aldolase. However, the ratio of activity towards the two substrates FDP/F1P is decreased in erythrocytes and reticulocytes. -- no other difference was found: Michaelis constant towards FDP, thermodenaturation constant and C terminal extremities are identical as are the molecular weights.

Amino Acids↗

[Passive smoking].

Passive smoking is the involuntary inspiration of smoky indoor air. Based on the information available today, it may be assumed that passive smoking normally is no health hazard as far as the classical smoker's diseases (lung cancer, myocardial infarct, etc.) are concerned. Nevertheless, it is probable that irritations caused by tobacco smoke have an unfavorable influence on the health of small children and that of already sick persons. The main problem of passive smoking is annoyance due to odor and irritations of eyes and respiratory organs. Our investigations in a climatic chamber with healthy subjects show that air pollution caused by tobacco smoke as indicated by 5 ppm CO leads to marked eye irritations--objectively as well as subjectively--in 15 to 20% of the subjects. This corresponds to smoking 10 cigarettes per hour in a small room with an air ventilation rate of four times per hour. If air pollution caused by tobacco smoke lies below the level of 2 ppm CO, irritations and annoyance for healthy persons are regarded as low and tolerable. This corresponds to about four cigarettes per hour under the same circumstances.

Adult↗