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Biomedical subjects

M A Ansari

Publications and source records attributed to M A Ansari.

At least 37 records · Page 2Linked to original sources
PubMed1999

Gonadotropin-releasing hormone increases CD4 T-lymphocyte numbers in an animal model of immunodeficiency.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) possesses immunostimulatory properties. We have previously demonstrated that GnRH antagonists decrease lymphocyte numbers in an animal model of autoimmune disease. We speculated that the converse might be true, that GnRH administration would increase lymphocyte numbers or alter lymphocyte subsets in an immunodeficiency state. OBJECTIVE: Our purpose was to test the hypothesis that GnRH agonist would increase IgG and CD4 counts in a rat model of immunodeficiency independently of gonadal steroids. METHODS: We used diabetes-prone (DP) BB rats. This model has been characterized to have an AIDS-like lymphocyte profile, with lymphopenia and depressed CD4 counts. Ovariectomized female DP rats were randomized to receive subcutaneous injections with GnRH or vehicle 6 times weekly. DR rats were ovariectomized and treated with vehicle as controls. We performed flow cytometric analysis and complete blood cell counts at baseline, 3.5 weeks, and 7 weeks of treatment. We also measured total serum IgG and luteinizing hormone levels. RESULTS: GnRH administration significantly increased total serum IgG levels in DP rats compared with vehicle. The percentages of CD4(+) cells in blood were also significantly increased in the GnRH-treated group compared with the vehicle-treated group and compared with baseline. Similarly, the absolute numbers of CD4(+) positive T cells were increased over controls at 7 weeks. The effects of GnRH were specific for the CD4 subset because there were no significant differences in numbers of CD8(+) positive cells between the 2 treatment groups. CONCLUSION: GnRH shows potential utility as an immunostimulatory agent in immunodeficient states manifesting diminished numbers of immunocompetent CD4(+) T lymphocytes.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Gender-specific exacerbation of murine lupus by gonadotropin-releasing hormone: potential role of G alpha(q/11).

We have previously demonstrated that GnRH and its analogues modulate the severity of murine systemic lupus erythematosus. In the present study, we demonstrate that GnRH alters disease severity in a sexually dimorphic fashion, even in gonadectomized mice. GnRH administration leads to an exacerbation of lupus in ovariectomized females, whereas it exerts no effect in castrated males. We initially hypothesized that gender differences in lymphocytic expression of GnRH receptor might explain these observations. Using competitive RT-PCR and binding studies to quantitate GnRH receptor expression in lymphoid organs, we found that GnRH administration led to decreased expression of GnRH receptor messenger RNA (mRNA) and GnRH binding, compared with vehicle, in spleens of ovariectomized females after 2 weeks of treatment. These decreases occurred concurrently with increased expression of interleukin-2 receptor mRNA and protein in females. GnRH administration did not alter GnRH receptor or interleukin-2 receptor mRNA or protein in castrated males. GnRH exerts actions on the pituitary through G protein signal transduction, specifically through G alpha(q/11). Competitive RT-PCR revealed that GnRH administration was associated with increases in the expression of G alpha(q/11) mRNA, compared with vehicle, in spleens in ovariectomized females but not in castrated males. Immunoblot analysis revealed a similar pattern. We conclude that gender differences in expression of G alpha(q/11) may contribute to gender differences in immunity and/or autoimmune disease.

Animals↗
PubMed1999

Renal lesions associated with AIDS--an autopsy study.

Kidneys from 55 cases (20 with HIV infection and 35 with AIDS) were studied by routine Haematoxylin and Eosin stains and special stains (PAS, PASM GMS, ZN, Mucicarmine and Congo red) to evaluate, glomerular, interstitial and vascular pathology. Twenty-four of the 35 (68.6%) cases of AIDS showed infective aetiology which included 17 cases (48.5%) of tuberculosis, 5 cases (14.4%) of fungal infection (3 cryptococcus neoformans and 2 candida species) and 2 cases (5.7%) of CMV infection. Other lesions noted were amyloidosis and tubular calcinosis. HIV associated nephropathy (HIVAN) was not detected in any of the cases. Intravenous drug abuse was not a risk factor in our cases which probably explains the absence of HIV associated nephropathy in the present study.

AIDS-Associated Nephropathy↗
PubMed1998

Relative efficacy of synthetic pyrethroid-impregnated fabrics against mosquitoes under laboratory conditions.

The efficacy of synthetic pyrethroid-impregnated fabrics was evaluated against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, under laboratory conditions. Results revealed that delta-methrin was significantly superior in comparison to lambdacyhalothrin and cyfluthrin. Results of bioassay tests revealed that deltamethrin was 1.5 and 1.9 times more effective than lambdacyhalothrin and cyfluthrin, respectively, against An. stephensi exposed to cotton fabric treated at 100 g/m2. Deltamethrin was 3.9 and 4.6 times more effective against Ae. aegypti and 3.53 and 4.0 times more effective against Cx. quinquefasciatus. Of cotton, nylon, polyethylene, and jute fabrics, the cotton was the best on the basis of median lethal dose (LD50) and 95% lethal dose (LD90) values and persistence of insecticide.

Aedes↗
PubMed1998

A longitudinal study of sero-reactivity to Plasmodium falciparum antigen in children and adult living in an endemic area of U.P.

Antibody levels of Pf RESA derived peptide R1 (EENVEHDA-C) from individuals living in malaria endemic areas correlated well with levels of endemicity. Serological and parasitological investigations were done in 32 adults (> 20 yrs) and 35 children (2-5 yrs) for three years; i.e. from 1992-95 periodically in village Piyawoli, U.P. Antibody levels against R1 peptide was estimated by ELISA, and blood smear for P. falciparum and P. vivax were screened using Jaswant Singh-Bhattacharya (JSB) staining. It appeared from our investigations that anti-R1 antibodies had a short span of life, i.e. 6-9 months. The longevity of these antibodies do not differ much in adults and children. The studies do not indicate any protective role for these antibodies. However, the levels of anti-R1 antibodies in a population living under malariogenic condition are related to Pf malaria endemicity.

Adult↗
PubMed1997

Thyrotropin-releasing hormone accelerates fetal mouse lung ultrastructural maturation via stimulation of extra thyroidal pathway.

Maternal administration of TSH-releasing hormone (TRH) in the euthyroid mouse accelerates fetal lung ultrastructural maturation. However, the mechanism(s) of TRH in fetal lung development remains unclear; it could be due to its neuroendocrine and/or neurotransmitter effects. Although the neuroendocrine effect of TRH is mediated via stimulation of the fetal pituitary-thyroid axis, the neurotransmitter effect is mediated via stimulation of fetal autonomic nervous system activity. In the hyt/hyt mouse there is a point mutation in the beta subunit of the TSH receptor in the thyroid gland of the Balb-c mouse. In these mice TSH does not bind to its receptors, leading ultimately to the development of primary hypothyroidism, which is transmitted as an autosomal recessive trait. A maturational delay in the lung ultrastructure of the hyt/hyt mouse fetus has been observed. This investigation was undertaken to study the effect of maternal TRH treatment on lung ultrastructural maturation in the hyt/hyt mouse fetus. If the effect of TRH is mediated via stimulation of fetal pituitary-thyroid axis, TRH treatment should not enhance lung maturity in the hyt/hyt fetus and vice versa. Adult hyt/hyt mice made euthyroid by triiodothyronine supplementation were mated to carry hyt/hyt pups. Saline or TRH (0.4 or 0.6 mg/kg/dose) was administered to the mother (i.p.) on d 16 and 17 (b.i.d.) and on d 18 of pregnancy 1 h before killing (term, approximately 20 d). The fetal lung electron micrographs were subjected to ultrastructural morphometric analysis of the number of lamellar bodies and glycogen/nuclear ratio in type II cells, and the alveolar/parenchymal ratio by Chalkley point counting with an interactive computerized image analyzer (Optimas, Bioscan). Fetal lungs exposed to the lower dose of TRH (n = 7) showed no significant difference in their ultrastructural maturation when compared with saline-treated controls (n = 5). However, fetal lungs exposed to a higher dose of TRH (n = 6) showed increased numbers of lamellar bodies per type II cell, an increase in the alveolar/parenchymal ratio, larger air spaces, thinner alveolar septa, presence of tubular myelin, and increased numbers of air-blood barriers. We conclude that the effect of TRH in accelerating fetal mouse lung maturation is at least in part mediated via stimulation of extra thyroidal pathways.

Animals↗
PubMed1997

Residual efficacy of deltamethrin 2.5 wp (K-othrin) sprayed on different types of surfaces against malaria vector Anopheles culicifacies.

Residual efficacy of deltamethrin 2.5 wp on various types of surfaces was tested against Anopheles culicifacies under field conditions using WHO standard procedure. Deltamethrin was most effective on the thatched surface and produced 100% mortality of An. culicifacies adults up to 12 weeks, even when exposed at the lowest dose /12.5 mg/m2. It was least effective on brick surface and 100% mortality was observed only for three weeks. The efficacy was observed for 8 and 7 weeks on mud and cement surfaces, respectively. However, at the higher rate of application, i.e. 25 mg/m2, 100% mortality of this species was obtained for 12, 10, 9 and 12 weeks on mud, cement, brick and thatch surfaces, respectively.

Animals↗
PubMed1996

High prevalence of chloroquine resistant Plasmodium falciparum infection in Rajasthan epidemic.

Plasmodium falciparum is the main killer among all human malaria parasites. In 1994, there was a falciparum malaria epidemic in Rajasthan, India, with many deaths. We have investigated active falciparum malaria cases from this epidemic and found that most of the parasite isolates (95%) were resistant to chloroquine. Nevertheless, all the tested isolates from the epidemic, were sensitive to mefloquine and quinine and ninety percent were also susceptible to sulfadoxine/pyrimethamine. Most individuals had moderate levels of TNF-alpha (20-220 pg/ml) and anti-parasite IgM antibodies compared to IgG levels which were relatively lower. In conclusion, the high transmission rate of the chloroquine resistant P. falciparum parasite could be the probable cause of the disease epidemic in Rajasthan. The timely drug sensitivity test and availability of appropriate antimalarial drugs are, therefore, warranted.

Animals↗
PubMed1996

Major differences in the spectrum of gastrointestinal infections associated with AIDS in India versus the west: an autopsy study.

The spectrum of bowel infections in patients with AIDS in India is not well characterized. To examine this spectrum of infections, an autopsy study of 49 subjects was carried out. Multiple sections were obtained from the gastrointestinal tract. A pathogenic organism was detected in 25 (71%) of 35 patients with diarrhea vs. 4 (29%) of 14 patients without diarrhea (P < .01). The most frequent pathogen was cytomegalovirus (in 13; 27%), followed by parasites (9; 18%), fungi (8; 16%) and Mycobacterium tuberculosis (7; 14%). This is the first autopsy study of patients with AIDS in the Indian subcontinent and shows important differences in the profile of their opportunistic infections compared with those of such patients in the West. These findings will help define the optimal diagnostic and therapeutic approaches to patients with AIDS, which, in view of the considerable budgetary restrictions in developing countries, should be targeted toward the pathogens most frequently identified in such areas.

AIDS-Related Opportunistic Infections↗
PubMed1996

Upper airway obstruction secondary to acinic cell carcinoma of the trachea. Use of Nd:YAG laser.

Comprising 1 to 4% of all tumors and 7 to 15% of malignant neoplasms of the major salivary glands, acinic cell carcinoma (ACC) rarely occurs in the respiratory tract. There has been only one case of ACC of the trachea previously reported in the medical literature. A second case of ACC of the trachea associated with upper airway obstruction and its management by Nd: YAG laser and surgical resection is reported.

Airway Obstruction↗
PubMed1996

Operational feasibility of malaria control by burning neem oil in kerosene lamp in Beel Akbarpur village, District Ghaziabad, India.

A field trial in Beel Akbarpur village, Dadri PHC, District Ghaziabad (U.P.) was carried out to test the impact of burning neem oil in kerosene lamp from dusk-to-dawn in living rooms on vector populations and incidence of malaria. Results revealed that burning 1% neem oil in kerosene lamps resulted in the deviation of An. culicifacies from living rooms to cattlesheds. This was also reflected when malaria incidence was compared in experimental and control villages. Cases/000 and Pf/000 were 1.03 and 0.0 in experimental village as against 9.6 and 4.3 in control village. Discontinuation of burning 1% neem oil in kerosene lamp resulted in recurrence of An. culicifacies in living rooms and increase in malaria incidence in experimental village.

Animals↗
PubMed1996

Study on the feasibility of delineating mosquitogenic conditions in and around Delhi using Indian Remote Sensing Satellite data.

A feasibility study to identify mosquitogenic conditions in six study sites in and around Delhi (Bhalaswa lake, Nazafgarh drain, Seelampur lake, Sanjay lake, Okhla barrage and Hindon barrage) using Indian Remote Sensing Satellites was carried out. The water bodies with marshy areas, vegetation and human settlements were considered as environmental variables responsible for mosquitogenic conditions. Multidate IRS 1A and B, LISS-II satellite data were collected and analysed on Vax 11/780 computers. False colour composite (FCC) images were generated and land cover assessed using supervised classification based on ground truth training sets. Ground truth validation of satellite data was done on satellite pass dates. Concurrent monitoring of larval and adult mosquito density was performed by selecting sub-sites in each study site. The results indicate that mosquitogenic conditions can be identified (with limitation of resolution, i.e. 36.5 m) using FCC images and these images can be used as base maps of study sites. Characterization of study sites based on land cover was done from the view point of mosquitogenic conditions. Spatial changes in mosquito density vis-a-vis changes in environmental variables revealed positive correlation with water bodies and vegetation in some study sites.

Animals↗
PubMed1996

Preliminary evaluation of safety aspects of neem oil in kerosene lamp.

Kerosene lamps containing one per cent neem oil were used for mosquito repellent action in a village near Delhi. The safety aspects of this personal protection method developed by Malaria Research Centre were evaluated by animal studies and clinical examination of population before and after exposure. Single application of neem oil (1%) did not produce skin irritation in rabbits and adverse effect on guinea pigs after exposure to aerosol. Clinical examination of 156 adults and 110 children did not reveal any major adverse effects after one year of exposure to 1% neem oil.

Adult↗
PubMed1996

Solitary thyroid nodule: a study of 100 cases.

One hundred cases of solitary thyroid nodules attending the thyroid clinic, Institute of Postgraduate Medicine & Research, Dhaka (IPGMR) and the Institute of Nuclear Medicine (INM) were included in a prospective study. Thyroid ultrasonography (USG), scintiscanning, radioactive iodine (I131) uptake (RAIU), estimation of serum total T3, T4 & TSH and Fine Needle Aspiration Cytology (FNAC) were performed in all cases. Surgical resection with histopathologic study was performed in selected cases. Extra-nodular part of the thyroid gland was normal in 68 and diffusely enlarged in 32, RAIU was normal in 62, high in 36 and very low in two subjects. Nodules were solid at USG in 67 subjects, cystic in 16 subjects and of mixed consistency in 17 subjects. Goitrous subjects had significantly lower T4 (p < 0.001) and higher T3 (p < 0.01) and TSH (p < 0.001) than non-goitrous ones. Colloid nodule was the commonest pathology occurring in 41 cases, followed by thyroid cysts (26), follicular adenoma (23), adenoma with cystic change (7), subacute thyroiditis (2) and papillary carcinoma (1). Colloid nodules were more common in goitrous subjects which could hint at iodine deficiency as the major cause of such nodules. Hyperfunctioning follicular adenomas occurred exclusively in non-goitrous subjects. Carcinoma appeared to be uncommon in patients with solitary nodules. It gives an opportunity to our physicians to be more conservative in selecting patients with solitary thyroid nodules for surgical treatment.

Adenoma↗
PubMed1995

Efficacy of two flowable formulations of Bacillus sphaericus against larvae of mosquitoes.

Laboratory evaluation revealed that the Spherimos and Vectolex formulations of Bacillus sphaericus produced 97 and 100% larval mortality respectively in Culex quinquefasciatus at a dose as low as 0.008 ml/sq m as against 93 and 97% mortality respectively at 1 ml/sq m in Anopheles stephensi. However, in An. culicifacies similar level of mortality was not observed even at 10 ml/sq m of these formulations. Field evaluation revealed 100% reduction of Cx. quinquefasciatus larvae for 2-3 weeks in pools and wells with single application of Spherimos @ 2 ml/sq m as against 95.4% reduction @ 10 ml/sq m in irrigation channel for one week. Vectolex @ 10 ml/sq m provided 99-100% reduction of Cx. quinquefasciatus larvae up to 9 weeks in wells and 1 week in channels.

Animals↗
PubMed1995

Relative efficacy of various oils in repelling mosquitoes.

Field studies were carried out to determine the relative efficacy of repellant action of vegetable, essential and chemical base oils against vector mosquitoes. Results revealed that essential oils viz. Cymbopogan martinii martinii var. Sofia (palmarosa), Cymbopogan citratus (lemon grass) and Cymbopogan nardus (citronella) oils are as effective as chemical base oil namely mylol. These oils provide almost complete protection against Anopheles culicifacies and other anopheline species. Per cent protection against Culex quinquefasciatus ranged between 95-96%. Camphor (C. camphora) oil also showed repellent action and provided 97.6% protection against An. culicifacies and 80.7% against Cx. quinquefasciatus. Vegetable oils namely mustard (B. compestris) and coconut (C. nucisera) showed repellent action, however the efficacy of these oils was not much pronounced against Cx. quinquefasciatus. Results of statistical analysis revealed significant difference between vegetable and essential oils (p < 0.01) against tested species of mosquitoes. Essential oils were found marginally superior in repellancy than camphor and mylol (p < 0.01) against An. culicifacies and Cx. quinquefasciatus.

Animals↗