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Biomedical subjects

V D Purohit

Publications and source records attributed to V D Purohit.

13 recordsLinked to original sources
PubMed1998

Abortion in guinea pigs by Chlamydia psittaci isolates from natural sheep abortion.

Experimental model for chlamydial abortion was planned using pregnant guinea pigs to study whether the isolate of Chlamydia psittaci from natural cases of sheep abortion is able to cause experimental abortion in pregnant guinea pigs or not. Follow up and clinical observations like thermal reaction and haematological changes exhibited biphaic febrile response and marked leucopenia in both intraperitoneal group as well as intravaginal group. The laboratory examinations revealed presence of chlamydial intracytoplasmic inclusions in the impression smears of aborted foetal tissues. C. psittaci was reisolated successfully from all the aborted foetal tissues. It was observed that rate and severity of abortion were more in the intraperitoneal group as compared to intravaginal group. On correlating the results of clinical and laboratory examinations it was observed that guinea pig can be used as a suitable model for chlamydial abortion in future studies like cell mediate immune response and to see protective role of chlamydial vaccine, if any.

Abortion, Veterinary↗
PubMed1979

Testicular response of non-breeding pheasants to human chorionic gonadotropin, chicken pituitary extract, and photoperiod.

This investigation was designed to compare the testicular response of non-breeding pheasants to human chorionic gonadotropin (HCG), chicken pituitary extract (CPE), and extended photoperiod exposure (20L:4D) by analyzing testicular weights, testicular histology, and plasma testosterone levels. Exposure to 20L:4D increased testicular weights and plasma testosterone levels significantly (P less than .01) and recovered spermatogenesis completely. Injections of CPE increased testicular weights (P less than .01) and recovered spermatogenesis partially, but had no significant effect on plasma testosterone levels. Effects of HCG were non-significant. It is suggested that either doses of HCG and CPE used in this study were not enough or non-breeding pheasants require pheasant gonadotropins for the complete recovery of testicular function.

Animals↗
PubMed1978

Effects of testosterone on the testes of sexually quiescent pheasants: evidence for a negative feedback mechanism.

1. The testicular response of sexually quiescent pheasants to testosterone was studied by injection of testosterone alone and in combination with chicken pituitary extract (CPE) for 20 d. 2. Testosterone alone caused a significant decrease in testicular weight, whereas CPE alone caused a significant increase. In combination testosterone and CPE caused no significant change in testicular weight, suggesting a suppression of the stimulatory effect of CPE by testosterone. The depressive effect of testosterone on testicular weight may be explained on the basis of negative feedback mechanism. 3. CPE alone stimulated the production of spermatogonia and primary spermatocytes whereas testosterone, alone or with CPE, did not elicit such a response. The lack of response of the germinal epithelium to testosterone may indicate the ineffectiveness of the hormone in initiating spermatogenesis in pheasants.

Animals↗
PubMed1978

Testosterone levels in the blood plasma of male chicken-pheasant hybrids.

Testosterone levels in the blood plasma of sterile male chicken-pheasant hybrids were compared with plasma testosterone levels of roosters and male pheasants, using radioimmunoassay. Mean values of testosterone in the roosters, male pheasants and chicken-pheasant hybrids during spring were 155.47 +/- 4.03, 24.29 +/- 1.55 and 0.68 +/- 0.05 ng./100 ml., respectively and the corresponding values for winter were 88.88 +/- 4.10, 0.61 +/- 0.04 and 0.76 +/- 0.07 ng./100 ml. The pheasant testes were inactive in winter but active in spring whereas the hybrid testes were inactive in winter and spring unlike those of roosters which were active during these seasons. The low levels of testosterone in hybrids during both seasons could be attributed to the impairment of steroid biosynthetic activity of the Leydig cells and may be causally related to the absence of secondary sexual characteristics and the interruption of spermatogenesis in chicken-pheasant hybrids.

Animals↗
PubMed1977

Histochemical localization of 3 beta-hydroxysteroid dehydrogenase in the testes of chicken-pheasant hybrids.

Histochemical studies on the activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) in the testes of adult chicken-pheasant hybrids and domestic fowl of similar age were carried out using dehydroepiandrosterone as the substrate. The reaction for 3beta-HSD was positive in the interstitial tissue and negative within seminiferous tubules of domestic fowl. In chicken-pheasant hybrids, a strong positive reaction for 3 beta-HSD was observed in the interstital tissue and within the seminferous tubules suggesting that, in hybrid testes, both Leydig cells and cells of seminiferous tubules may be capable of steroid biosynthesis. Since the plasma testosterone levels in these birds were found to be extremely low, it is hypothesized that either the chicken-pheasant hybrids do not release testosterone in sufficient amounts in the circulation or the type of steroid produced by the 3 beta HSD-positive cells may be different from testosterone that is required for the maintenance of normal fertility and the development of secondary sexual characteristics.

Animals↗
PubMed1977

Exencephaly in chicken-pheasant hybrids.

1. The incidence of exencephaly was investigated in chicken-pheasant hybrids. 2. With the pheasant as sire, fertility was 7-6%, but with the fowl it was 19-5%; hatchability of fertile eggs, however, was similar, 42% and 41% respectivley. 3. Only one exencephalic hybrid was obtained when the sire was the pheasant but 70 were noted when the fowl was sire. The incidence of this malformation in hatched chicks was 12 times more in crosses with the fowl as sire than in the reverse cross. 4. The frequency of exencephaly was greater with Rhode Island Red, Barred Leghorn or White Leghorn roosters than with Columbian Rock roosters.

Animals↗
PubMed1977

Persistent right oviduct in ring-necked pheasant.

1. A right oviduct, approximately two-thirds the length of the left oviduct, and with a separate opening into the cloaca was observed in a female Ring-necked pheasant. 2. It is suggested that interference of the synthesis of Müllerian inhibiting factor from the gonads may have allowed its development.

Animals↗
PubMed1977

Effect of extended photoperiod on the spermatogenic activity of chicken-pheasant hybrids.

1. Males of chicken-pheasant hybrids and non-breeding pheasants were exposed to photoperiods of 10 or 20 h/d to test the effect of light on spermatogenic activity. 2. Testicular weights of hybrids and pheasants exposed to 10 h/d were similar and extending the photoperiod did not increase this in hybrids, although it caused a 48-fold increase, and complete recovery of spermatogenic activity, in pheasant. 3. Extending the photoperiod caused an increase in the number of primary spermatocytes and a corresponding decrease in the number of spermatogonia in hybrids, however, stages beyond primary spermatocytes were not present. This suggests that the stimulus of extending the photoperiod, while sufficient to induce meiosis in existing germ cells, is not enough to effect proliferative bursts or to overcome the meiotic arrest in the hybrids.

Animals↗