Search PubMed⌕ Search

Biomedical subjects

P Vasilenko

Publications and source records attributed to P Vasilenko.

27 records · Page 2Linked to original sources

Diabetes induced by streptozocin results in a decrease in immunoreactive beta-endorphin levels in the pituitary and hypothalamus of female rats.

Immunoreactive beta-endorphin (IR-BE) was measured by radioimmunoassay in the anterior pituitary (AP), neurointermediate lobe of the pituitary (NIL), and hypothalamus of female rats 4 wk after being made diabetic by a single injection of streptozocin (STZ). STZ-induced diabetes resulted in a significant reduction in the content and concentration of IR-BE in the AP and the content of IR-BE in the hypothalamus. Total hypothalamic protein was also significantly diminished. IR-BE levels in the NIL were unchanged. Column chromatography indicated that the reduction in IR-BE in the AP of the diabetic female rats represented a decrease in peptides that co-eluted with beta-endorphin and beta-lipotropin. In the hypothalamus, the reduction in IR-BE was represented solely by a decrease in a peptide co-eluting with beta-endorphin. Beta-lipotropin was not detectable in the hypothalami of control or diabetic female rats. These results suggest that, in the rat, diabetes may produce alterations in the mechanism(s) that regulate endogenous opiate levels in the pituitary and hypothalamus.

Animals↗

Effects of long- and short-term vasectomy on structural and functional parameters of the rat.

The effects of vasectomy were examined by comparing various parameters from sham operated and vasectomized rats that had undergone surgery at 90 days of age and were killed at 190 or 390 days of age. Significant alterations in the vasectomized rats from sham rats included: testicular and epididymal hypertrophy, formation of pathologic vas deferens granulomas, decreased total serum protein, lowered alpha-globulin levels as shown by serum electrophoresis, and increased sperm agglutinin antibody titers. For vasectomized rats, the differential white blood cell count showed increased numbers of neutrophils and large lymphocytes and decreased numbers of small lymphocytes and basophils. Both the number and extent of many vasectomy-induced alterations were greater in long-term vasectomized than in short-term vasectomized rats.

Animals↗

Effects of early maturation on fetal growth.

While the association of young maternal age with low birthweight (LBW) is well known, the contribution of early menarche to this association has never been studied. We examined the effects of early menarche (less than or equal to 11 years) on LBW and its two major underlying causes: pre-term delivery and smallness-for-gestational-age (SGA). Results represent a narrow chronological age range, 17-18 years, of a larger geographically based cohort of 2789 pregnant adolescents. Adjusted odds ratios (AOR) indicated that early menarche was significantly associated with an increased risk of LBW which was specific to SGA. The attributable risk of SGA with early menarche exceeded 20%. Early age at menarche is also correlated with an earlier onset of sexual activity, pregnancy, and childbearing. Consequently, adolescents with early menarche are over-represented in a sample limited to young gravidae or a sample that contains a stratum of young gravidae. This may have previously obscured the effects or early menarche on foetal growth and attributed them to a more frequently measured characteristic, young maternal age. Thus, effects of secular change in age at menarche may not be wholly benign. Improvements in maternal fertility and nutritional status appear to be offset by intrauterine growth retardation in the offspring.

Adolescent↗