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Biomedical subjects

P Bhatnagar

Publications and source records attributed to P Bhatnagar.

At least 37 records · Page 2Linked to original sources
PubMed1990

Organochlorine residues in water from the Mahala water reservoir, Jaipur, India.

Residues of p,p'-DDE, p,p'-DDT alpha-, beta-, gamma-isomers of HCH, aldrin and heptachlor in water, from four different sites of the Mahala water reservoir were monitored periodically from September 1985 to October 1987. All the samples contained the above residues in varying concentrations. Isomers of HCH predominated and were followed in relative dominance by aldrin, total DDT and heptachlor residues, p,p'-DDE and p,p'-DDD constituted the major fraction of total p,p'-DDT. Monthly total organochlorine residue levels in water ranged between 1.07 and 81.23 microg litre-1. The variation is attributed to the run-off or subsoil water movement from the catchment area.

Journal Article↗
PubMed1989

Necessity of adjuvants for inducing effective antibody response to zona pellucida antigens.

Rhesus monkeys evoked a vigorous antibody response to a single heteroimmunization dose of zona pellucida antigens, when these were administered along with complete Freund's adjuvant. The antisera recognized all the three major porcine zona glycoprotein families and the animals were rendered amenorrheic after such immunization. Monkeys immunized with zona without adjuvant, however, failed to show any anti-zona antibody response and had normal menstrual cycles. Zona pellucida glycoproteins are thus not effective immunogens unless administered along with a powerful adjuvant.

Adjuvants, Immunologic↗
PubMed1989

Embryotoxic and teratogenic studies of phosphamidon in Swiss albino mice.

Phosphamidon, an organophosphate pesticide, is little known for its possible effects on mammalian conceptus. The present investigation was carried out to evaluate its embryotoxic and teratogenic effects on Swiss albino mice. Female mice of similar age and weight were divided into four experimental groups. The animals of groups I and II received 15 and 35 ppm phosphamidon ad libitum, respectively, during the entire gestational period, that is, from days 1 to 18. Groups III and IV were treated before mating with 35 ppm phosphamidon for 30 and 60 days, respectively, and the treatment was continued during pregnancy up to the 18th day. The autopsies were performed on the 18th day of gestation, and routine teratological observations were made. The lower dose did not produce significant effects. The higher dose reduced the number of implants, litter size, and foetal weight and increased the resorption of embryos when administered for 30 days prior to mating. Exposure to the pesticide for 60 days prior to mating and during gestation, however, did not produce significant effects. It appears that the mice probably developed some resistance to the pesticide, when exposed for such a long duration.

Animals↗
PubMed1989

The effects of dieldrin, dimethoate and permethrin on Tetrahymena pyriformis.

The effects of three insecticides, dieldrin, dimethoate and permethrin, on the growth of a holotrichous ciliate, Tetrahymena pyriformis, were studied for 5 days. The ciliate was very sensitive to dieldrin and dimethoate. Both these insecticides produced approximately 81% and 84% inhibition of growth within two days. Dieldrin caused rounding of cells, while dimethoate induced cell lysis. Dimethoate also triggered a general mucocyst discharge. Of the three insecticides, permethrin was the least toxic and induced no morphological alterations.

Journal Article↗
PubMed1989

Long-term effects of immunization with porcine zona pellucida on rabbit ovaries.

Groups of rabbits were immunized with 4 doses of porcine zona pellucida antigen along with different adjuvants. The presence of antibody after immunization was checked periodically using different assay systems. The impact of immunization on ovaries was evaluated at different time intervals up to 2 years. Results of the study showed generation of high titre antibodies which could be detected until the end of the period of observation. The antibodies specifically bound to zona pellucida in situ were demonstrated by immunoperoxidase staining, and in vitro by inhibition of enzymatic digestion of zonae. Histologically, antibodies had numerous pathological effects on ovaries including thinning of the cortex, aberrant cell clusters, stromal cell hyperplasia, perifollicular fibrosis, irregular zona formation and arrest of follicle development. These changes could be correlated with the length of exposure to antibodies. It is concluded that heat-solubilized porcine zona (HSPZ) protein is a very strong immunogen and causes infertility by arresting the maturation of developing follicles. There is a need to identify the sperm receptor so that immunization could selectively impair sperm-egg interaction.

Animals↗
PubMed1989

Condylomatous lesion (HPV infection) of uterine cervix. A clinical, colposcopic, cyto, histomorphological and immunohistochemical study.

43, patients, subjected to cervical cytology, colposcopy and colposcopic directed biopsy, were found to have lesions suggestive of human Papillomavirus (HPV) infection by one or more parameters. Immunohistochemical staining for HPV antigen yielded positive results in 23 (53.5 p. cent) cases. Amongst 30 cases with HPV lesions both in cytology and histopathology, 19 (63.3 p. cent) were positive for the HPV antigen. This was significantly higher as compared to the groups where HPV lesion was observed in cytology or histology alone (p = 0.05). The rate of positivity was the highest (81.3 p. cent) in a group of 16 patients having low grade dysplasia (mild to moderate) and both cytology and histologic evidence of koilocytotic changes. Presence or absence of HPV lesion by colposcopic examination in these 43 cases did not make any significant difference in rate of antigen positivity.

Adult↗
PubMed1989

Dapsone drug compliance study among leprosy patients: a comparison between qualitative and quantitative methods.

The methods currently employed to monitor self-administration of dapsone have been evaluated by comparing the results of the qualitative spot test and quantitative DDS/creatinine ratio test. Random urine samples of 242 leprosy patients, periodically attending the Leprosy Clinic were tested. Although a good correlation between the results of the two tests was evident, the DDS/creatinine ratio technique appeared to be more sensitive than the spot test. The concentration of DDS and its metabolites in urine specimens found to be negative by the spot test, ranged from 3.32-12.37 micrograms of DDS/mg creatinine. The spot test was found to be more specific and stays to be the method of choice, when rapidity and reproducibility are the prime objectives, and sensitivity can be marginally compromised. Acidification of urine prior to the spot test was found to be desirable to rule out false negative and false positive reactions.

Creatinine↗
PubMed1988

Uptake of dieldrin, dimethoate and permethrin by cyanobacteria, Anabaena sp. and Aulosira fertilissima.

Blue-green algae showed a poor ability to pick up and concentrate dieldrin and dimethoate. However, the uptake and bioconcentration factor for permethrin was very high. The uptake of dieldrin by Anabaena and Aulosira ranged from 5.1 to 73.2 and 5.5 to 17.4 microg g(-1) (ppm), respectively. The uptake of permethrin was from 9.0 to 249.7 and 4.6 to 1422.5 microg g(-1) by Anabaena and Aulosira, respectively. The highest bioconcentration factors for permethrin in Anabaena and Aulosira were 813 and 2373, respectively. This was followed by the bioconcentration factor of dieldrin (620) and dimethoate (119) in Aulosira fertilissima.

Journal Article↗
PubMed1988

Evaluation of the teratogenic potential of phosphamidon in mice by gavage.

Phosphamidon, an organophosphate pesticide, is an established cholinesterase inhibitor. Alteration of tissue and plasma cholinesterase activity at a critical developmental period may influence cellular division and growth sufficiently to produce anatomically or functionally abnormal tissue or organ. The present study was, therefore, undertaken to evaluate the teratogenic potential of phosphamidon in pregnant Swiss albino mice, when administered at different gestational days during the period of organogenesis. The animals were sacrificed on day 18 of gestation for routine teratological examinations. It was observed that phosphamidon was more embryotoxic than teratogenic. Maximum effects were observed when administered on day 7 and day 13. Treatment on day 10 produced little effects. Repeated exposure during the organogenetic phase also produced significant adverse effects. This possibly indicates that phosphamidon is more embryotoxic during the post-implantation period (day 7) and during late organogenesis (day 13) as compared to the early organogenesis period (day 10).

Abnormalities, Drug-Induced↗