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Biomedical subjects

R Kaur

Publications and source records attributed to R Kaur.

At least 55 records · Page 3Linked to original sources
PubMed1994

Effects of dietary selenium on differentiation, morphology and functions of spermatozoa of the house rat, Rattus rattus L.

Ingestion of 2 ppm and 4 ppm selenium in the diet by the house rat, Rattus rattus, for 5 weeks caused a dose-dependent reduction in its body weight, testicular and cauda epididymidis weights, concentration, motility and percentage of live spermatozoa with a simultaneous increase in the percentage of their abnormal forms. Compared to 1.39% abnormal spermatozoa in cauda epididymidis in untreated control rats, 3.89% and 24.64% abnormal spermatozoa were observed in rats with 2 ppm and 4 ppm dietary selenium respectively. Ingestion of 4 ppm selenium had no significant effect on abnormalities of the head and neck regions but abnormalities of the midpiece region and multiple abnormalities increased significantly. Analysis of the various stages of differentiation of spermatids in the testis has revealed that with 4 ppm dietary selenium, the abnormalities are induced mainly in the midpiece region of the flagellum which is a site of energy production.

Animals↗
PubMed1994

Spermatogenic cells and stages of the seminiferous epithelial cycle in the Indian gerbil field rat, Tatera indica.

Four types of spermatogonia (A0, A, In, B) are distinguished in T. indica. Four generations of A type, a single generation of intermediate (In) and two generations of B type spermatogonia are identified. Seven divisions of spermatogonia have been observed, in Stages 1b, 2b, 3b, 4b, 5, 6 and 7 respectively. Spermatocytes have been observed in prophase, metaphase, anaphase and telophase; in terms of size and morphology, the phases of prophase could be further divided. Pre-leptotene and leptotene appear in Stage 8 and Stage 1 respectively. Round spermatids become asymmetrical in Stage 1b. For the first time in rodents, Stages 1, 2, 3, 4 and 8 have been subdivided. The percentage frequencies of Stages 1-8 are 12.93, 10.69, 17.54, 10.33, 3.76, 11.20, 7.88 and 25.67 respectively. Although the morphology of the spermatogenic cells and associations of these cell types are basically similar to those in albino rats, T. indica markedly differs from all other rodents studied in having two generations of B spermatogonia and subdivisions of Stages 1, 2, 3, 4 and 8; in addition, the relative frequencies of the stages distinctly differ from those recorded in previous studies of rats. Hence, the durations of different cell types in T. indica may differ markedly from those in other rodents.

Animals↗
PubMed1993

Studies on the pathophysiological mechanism of Campylobacter jejuni-induced fluid secretion in rat ileum.

Calcium has been reported to play an important role in regulating the intestinal electrolyte transport via Ca2+/calmodulin (CaM) and/or protein kinase C (PKC) systems. The role of Ca2+, CaM and PKC in the pathogenesis of Campylobacter jejuni-induced fluid accumulation was studied in vivo in ligated rat ileal loops. Calcium ionophore A23187 (5 microM) and PKC activator, phorbol-12-myristate-13-acetate (PMA, 100 micrograms kg-1) when injected alone induced fluid accumulation in the control loops. However, these modulators did not enhance further C. jejuni-induced fluid accumulation when injected along with C. jejuni live culture in the experimental loops. Both 1-verapamil (100 microM) and PKC antagonist, H-7 (15 micrograms/ml-1) significantly reduced C. jejuni-induced fluid accumulation (P < 0.001). The effect of CaM antagonist W-7 (60 microM) on C. jejuni-induced fluid secretion was not significant (P > 0.05). Our findings suggest that both Ca2+ and PKC appear to be the important second messengers involved in the stimulation of intestinal fluid accumulation in C. jejuni infection.

Animals↗
PubMed1993

A birth control vaccine is on the horizon for family planning.

Vaccines for control of fertility are likely to have an important impact on family planning methods. They are designed to act by mobilization of an internal physiological process and do not require external medication on a continuous basis. A number of birth control vaccines are at different stages of development, the most advanced being a vaccine inducing antibodies against human chorionic gonadotrophin (hCG). This vaccine consists of a heterospecies dimer (HSD, beta hCG associated with alpha-subunit of ovine luteinizing hormone, beta hCG:alpha oLH) linked to tetanus toxoid (TT) or diphtheria toxoid (DT) as carriers. The vaccine has recently passed an important milestone; it has completed the first leg of phase II efficacy trials. Women of proven fertility leading active sexual life were protected from becoming pregnant at antibody titres > or = 50 ng of hCG bioneutralization capacity per ml. This vaccine has previously been demonstrated to be reversible in its effect. It is free from any notable side-effects on endocrine, cardiovascular and other body functions. Ovulation was not disturbed and menstrual regularity was maintained. A logistic disadvantage of the present vaccine is the requirement for multiple injections. This is expected to be overcome by encapsulation of the requisite doses of the vaccine in biodegradable microspheres, which could be given at a single contact point for sustained antibody titres lasting over a year. A live recombinant vaccine has also been made that elicits high anti-hCG titres in monkeys for nearly 2 years following primary immunization and a booster at 8-9 months.

Adult↗
PubMed1990

Gossypol-induced inhibition of glucose uptake in human ejaculated spermatozoa may be mediated by lipid peroxidation.

Gossypol, a plant-derived polyphenolic compound known to exert contraceptive actions in men, inhibits 14C-glucose uptake in vitro in human ejaculated spermatozoa. Spermatozoal glucose uptake was found to increase monotonically up to 40 min, and then decreased by 60 min, possibly because of the saturation of the transport loci in the membrane. Gossypol at the concentrations of 5 and 10 microns caused a reduction of both the linear portion of the uptake and the fall afterwards. Gossypol similarly affects both the Na-dependent and -independent glucose uptake. The kinetic parameters of glucose uptake indicate that gossypol might be interfering with the transport/carrier protein as reduction in maximum uptake velocity (Vmax) was observed without any change in the affinity constant (Km). Similarly, gossypol also produced an increase in spermatozoal lipid peroxidation as evidenced by a steep rise in thiobarbituric acid reaction products in the human sperm cells. A significant decrease in total phospholipid level and the individual classes was noted after gossypol addition. Gossypol-induced inhibition of glucose uptake may be related to the generation of lipid peroxides and consequent membrane damage.

Glucose↗
PubMed1990

Pathology of ovary, uterus, vagina and gonadotrophs of female mice fed on Zn-deficient diet.

Dietary Zn-deficiency in mature female mice for 6 weeks caused a retardation of ovarian growth characterized by lack of vesicular and Grafian follicles, degenerated corpus luteum, distorted cell membranes of granulosa cells with pycnotic nuclei, poor development of theca interna, inordinate accumulation of sudanophilic granules in theca interna and interstitial cells. The vagina and uterus did not exhibit cyclic changes in their cytoarchitecture as a result of the cessation of estrous cycle after 6 weeks of dietary treatment. They displayed wide spread degenerative changes in their myometrial and endometrial layers. The uterine glands appeared collapsed with little or no secretion. The vagina lacked cornification. Their gonadotrophs reacted positive to PAS, identical to the control group observed at diestrous stage. However, they did not display a negative reaction, characteristic of the gonadotrophs at estrous stage of the control group, examined even at an interval of 1 day for 6 days in succession. These results point towards the suspension of steroidogenesis inspite of intact gonadotrophs under Zn-deficiency condition.

Animals↗
PubMed1989

Feasibility of controlling lymphatic filarial diseases through primary health care system.

A study was undertaken to explore the feasibility of treatment of clinical cases of filariasis by the Village Health Guides (VHG) and to assess the impact of different dose schedules by Diethylcarbamazine (DEC) on the frequency of acute attacks. It was observed that six days treatment with DEC at a dose of 500 mg daily was the most effective regimen in controlling recurrence of filarial attacks. The VHGs can serve the community in treating filarial cases with DEC.

Community Health Workers↗
PubMed1988

Correlation of histologic types of carcinoma of the uterine cervix and human papillomavirus and herpes simplex virus type 2 DNA sequences in the uterine cervical biopsies.

Forty patients with invasive cancer of cervix from New Delhi were examined for the presence of human papillomavirus (HPV) and herpes simplex virus (HSV) type 2 DNA sequences in a Southern hybridization assay. Data were analysed according to the histologic type of cancer. HPV DNA sequences were detected in 82.5% biopsies and HSV-2 DNA sequences were found in 10% biopsies. HPV-16 DNA sequences were found either alone or together with HPV-18 and/or HSV-2 Bgl II N fragment in 55% biopsies from keratinizing squamous cell carcinoma, whereas HPV-18 sequences were found in 35% biopsies. Similarly, 50% biopsies from patients with non keratinizing squamous cell carcinoma contained HPV-16 DNA and 38.9% biopsies had HPV-18 DNA. HSV-2 Bgl II N DNA sequences were present in 10% biopsies which were also positive for HPV-16 and/or HPV-18 DNA sequences. Two biopsies from adenocarcinoma of uterine cervix contained HPV-18 and HPV-16 DNA sequences. Therefore, no significant correlation seems to exist between HPV-types and histologic types or grades of differentiation of tumor.

Adenocarcinoma↗