Biochemistry and experimental biology最新文献

The action of Solcoseryl, a free protein extract of calf blood, was studied on chick embryo fibroblasts cultivated in vitro. Solcoseryl stimulates the permitotic DNA synthesis and increases the number of mitoses.,

Effect of whole body gamma irradiation (1200 r) on spleen lipid metabolism of male and female rats 24 hrs and 48 hrs after irradiation and the effect of radioprotective chemicals vis. AET, serotonin, their mixture and cystamine on radiation induced changes in spleen lipid metabolism has been studied. In male rats both 24 and 48 hrs after irradiation a significant increase in spleen total lipids, cholesterol, phospholipids, phosphatidylethanolamine and phosphatidylcholine was observed. Administration of AET before irradiation prevented the changes in spleen total lipids and cholesterol but not in phospholipids, which was prevented by prior administration of both serotonin and the mixture of serotonin and AET. In female rats 24 hrs after irradiation only spleen total lipids showed an increase which was prevented by prior administration of cystamine. In male rats, 24 hrs after irradiation the incorporation of NaH2 32PO4 (counts/min/ug PLP and counts/min/g spleen) into spleen total phospholipids, phosphatidylcholine and phosphatidylethanolamine was reduced and this was corrected by prior administration of AET. Serotonin and the mixture of serotonin + AET did not protect the specific activity of phosphatidy choline. In female rats irradiation increased the incorporation of NaH2 32PO4 into phosphatidylcholine, which was not prevented by prior administration of cystamine. The fatty acid composition of spleen lipid of female rats was profoundly altered 24 hrs after irradiation. Palmitic acid and oleic acid showed an increase whereas arachidonic and fatty acid above arachidonic acid showed an decrease, which were corrected by administration of cystamine before irradiation.

Cell populations of rat stomach have been counted following varying (4-60 days) periods of magnesium-deficient diet and compared to a control group. The activity of beta-glucuronidase and the serotonin concentration were assayed in magnesium-deficient and control rats within four weeks. In the rat stomach the magnesium deficiency produces a numerical decrease in mucous cells, especially marked after 3 and 4 weeks. At this time, the activity of beta-glucuronidase decreases significantly. The concentration of serotonin increases at an earlier time and this increase coincides with the onset of the typical erythema occurring in magnesium-deficient rats.

The dietary stress conditions such as starvation influenced Na+K+-ATPase activity which increased steadily above normal fed levels between the starvation periods of 24--48 hr. Also, an increased enzyme level was observed in alloxan diabetic rats and administration of insulin to diabetic rats led to a tendency towards a lowering of Na+K+-ATPase. Adrenalectomy brought about a lowering of Na+K+-ATPase activity from those of normals while the administration of hydrocortisone induced an enhancement. The results indicate that both starvation and diabetic conditions might cause a stress-like activation of adrenal cortex resulting in increased levels of glucocorticoids which in turn activate the intestinal Na+K+-ATPase activity.

Daily blood samples over a fifteen day period were obtained from two adult female black-tailed deer and circulating levels of progesterone, estrogens, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin were measured by radioimmunoassay. LH levels showed an apogee at the time when there was observed estrous behaviour. The length of the estrous cycle appeared to be 7 days. Progesterone levels peaked just subsequent to the LH peak. High estrogen levels coincided with high progesterone and prolactin levels. FSH reached maximum levels prior to peak estrogen levels. LH and FSH levels reached maxima on different days. There were two steroid peaks between the LH apogees.

The effect of Peptichemio (PTC) on cellular growth and on macromolecular syntheses was analyzed through the cell cycle of EUE cells. The cell response to the various treatments was measured by determining plating efficiency, growth rates and incorporation of labelled precursors of DNA, RNA and protein syntheses. Three maximum inhibition points were found on cell survival, one corresponding to the early G1, another to the middle S and a last one to the late G2. Parallel experiments of incorporation of labelled precursors of DNA, RNA and proteins revealed an effect only on DNA during the early and middle S phase.

Bioassay experiments showed the presence of sex pheromone in females of Poecilocerus pictus. It was further confirmed experimentally that the sex pheromone substances are secreted in the metathoracic and first two abdominal segments. Dissections of the females revealed the presence of a thin sac-like gland in the metathoracic segment. Ethernal extract of this gland was tested in a bioassaying apparatus to confirm its identity as a sex pheromone producing organ.

The antagonistic substances used in our experiments showed various relationships to the pathogenic protozoa Trichomonas foetus. Theseinacid and L-2-Methyl-2-Aminoaethenole demonstrated comparable inhibiting influences on the Trichomonas population. Puriniribosid, 6-Mercaptopurine, 4-Mercaptopteridine and Decobald-Cobamide exercised no recognisable influence on the Trichomonas foetus.

Free amino acids composition of six Heteropteran insects belonging to aquatic and terrestral habitate has been observed and it is suggested that the distribution of proline is related to the habitate of these insects. Proline probably plays a role in the retention/conservation of the water in terrestrial insects.

Frequency distributions of ten biochemical parameters are reported for a sample (40000 events) of the populations of Milano. Average values and standard deviations have been calculated for the female and male populations, subdivided in four classes of age. The values of the parameters increase with age; generally, except in the case of the rate of sedimentation, the values for the female population are lower with respect to those for the male population.