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Biomedical subjects

P Bhatnagar

Publications and source records attributed to P Bhatnagar.

46 records · Page 3Linked to original sources
PubMed1978

Histopathology and histochemistry of the insects treated with chemosterilants VI: brain damage including reduced neurosecretion caused by chemosterilants in Periplaneta americana (L).

The brain is damaged and neurosecretion is reduced in the P. americana treated with chemosterilants thio-tepa and bis (dimethylamino) dithiazolium chloride. The damage includes, separation of neurolemma, vacuolisation and chromatolysis in the nuclei of neurons and extensive damage to fibres. Reduced neurosecretion, vacuolisation in the cytoplasm and karyolysis in the nucleus of neurosecretory cells, are also observed. These changes in the brain are of considerable importance to understand the mode of action of the chemosterilants.

Animals↗
PubMed1976

Chloroplast coupling factor 1: A species-specific receptor for tentoxin.

Tentoxin, a cyclic tetrapeptide, induces chlorosis in certain plant species. It inactivated photophosphorylation and coupling factor 1 (CF(1)) ATPase in lettuce, a sensitive species. This effect was due to binding of tentoxin with CF(1) at a single site (affinity constant 1.3 to 20 x 10(7) M(-1)). Neither AMP nor adenyl-5'-yl imidodiphosphate appeared to bind to this site. In radish, an insensitive species, 20 times more tentoxin was required for 50% inhibition of photophosphorylation. In this species CF(1) ATPase was unaffected by tentoxin, and its CF(1) bound tentoxin only weakly (affinity constant less than 1 x 10(4) M(-1)). Sensitivity of photophosphorylation to tentoxin was correlated with chlorosis sensitivity in six other species examined.

Journal Article↗
PubMedDate not supplied

Immunogenicity of deglycosylated zona pellucida antigens and their inhibitory effects on fertility in rabbits.

Influence of carbohydrates on the immunogenicity and immunocontraceptive potential of zona pellucida glycoproteins has been investigated in rabbits. Porcine zonae pellucidae, following deglycosylation with trifluoromethane-sulfonic acid, retained significant immunogenic potential, as shown by the ability to generate antibodies which cross-reacted with the heterologous antigen. Antibody response, however, was much stronger against the native zona glycoproteins, thereby suggesting that both carbohydrate and protein moieties contribute to the overall immunogenicity of the zona pellucida antigens. Contraceptive efficacy of active immunization with the deglycosylated zona antigens, when evaluated by mating experiments, demonstrated inhibition of fertility in all immunized rabbits. Normal ovarian functions were disrupted in these animals, as revealed by the reduction in ovarian weights and gross impairment of folliculogenesis. Flushing of the oviducts of the immunized animals yielded a markedly reduced number of ova ovulated in response to hCG administration, none of which were fertilizable. Results collectively suggest that active heteroimmunization with deglycosylated zona pellucida antigens is effective in reducing fertility in rabbits.

Analysis of Variance↗
PubMedDate not supplied

Natural history of precancerous and early cancerous lesions of the uterine cervix.

A prospective study of cervical dysplasia cases and control cases matched for age and parity was undertaken in search of factors related to cervical carcinogenesis. Cytologic examination of 66,736 women revealed negative findings in 28.5%, inflammation in 70.3%, dysplasia in 1.4% and carcinoma in 0.1% of the cases. Data on epidemiologic features, cytomorphologic characteristics and serologic findings of antibodies to herpes simplex virus (HSV) were collected for proven cancer patients, dysplasia cases and control subjects. Cancer patients revealed significantly elevated antibodies to HSV as compared to the controls. The analysis revealed a higher proportion of dysplasia cases with an age at consummation of marriage of less than or equal to 15 years as compared to controls, with a relative risk of 1.5 (P less than .05). Similarly, a higher proportion of women with dysplasia had HSV-II-specific antibodies as compared to control women. The relative risk was found to be 1.3, which was not statistically significant (P greater than .05). The Mantel-Haenszel summary relative risk between antibodies to HSV and the two groups (dysplasia cases and controls), adjusted for the age at consummation of marriage, worked out to be 1.38, which was also statistically not significant (P greater than .05). The overall progression rate of dysplasia to malignancy was found to be 11.7% at the end of 54 months (during a total follow-up period of 84 months). Progression to cancer was highest in severe dysplasia cases and less in mild dysplasia cases. The progression rates were also significantly higher in the group of women who revealed antibodies to HSV II. Similar differences in the progression rates were observed with regard to the age at consummation of marriage.

Adult↗
PubMedDate not supplied

Cytologic monitoring of women using copper-containing intrauterine devices: five-year follow-up study.

Cytologic monitoring of the epithelia of the female genital tract in 2,603 women using copper-containing intrauterine devices (Cu IUDs) was carried out, with a detailed cytomorphologic study of the cervical smears. The women were followed-up to a maximum period of 60 months of study. The rate of dysplastic lesions in the initial smears was 2.5%. Grouping the 60 months into five time intervals of one year each, the annual rates of dysplasia at follow-up were 4.2%, 1.6%, 3.8%, 0.9% and 3.0%. The rate of dysplasia development in women with initially negative or inflammatory smears did not change significantly during the five years. No dysplasia progressed to carcinoma during the follow-up period. No difference in the behavior of dysplastic lesions detected at the initial stage as compared to those developing during the course of Cu IUD use was observed during the study. This study indicated that there is no significant risk of an increased incidence of cervical dysplasia or carcinoma development in women using copper-containing IUDs for five years.

Adolescent↗
PubMedDate not supplied

Epidemiologic analysis of Trichomonas vaginalis infection in inflammatory smears.

Infections of the lower reproductive tract are common in Indian women of reproductive age. Hospital-based cytologic screening was undertaken on 63,265 women. The smears were examined for the presence of specific infections, such as Candida, herpes simplex virus, human papillomavirus, Trichomonas vaginalis (TV) and Chlamydia. This paper highlights the prevalence of TV infection in inflammatory cervical smears. Among the various infections detected, the rate of TV infection was the highest (5.1%). On further analysis the rate of TV infection showed an increasing trend up to the age of 49 years; an inverse association was observed with the educational status of the women. The prevalence was high in women with clinical signs (vaginitis, 6.9%) and low in those with a prolapsed uterus (1.2%) as compared to a normal cervix. These observations reveal the need for providing proper counseling and education on sexual behavior and genital hygiene besides treatment to control and prevent these infections.

Adult↗