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Biomedical subjects

R N Sharma

Publications and source records attributed to R N Sharma.

At least 19 recordsLinked to original sources
PubMed2006

Seroprevalence of Toxoplasma gondii in pregnant women and cats in Grenada, West Indies.

Prevalence of antibodies against Toxoplasma gondii was studied in 534 pregnant women and 40 domestic cats in Grenada, West Indies. Antibodies (IgG) for T. gondii were sought in human sera by an enzyme-linked immunosorbent assay and in cat sera by using the modified agglutination test (MAT). Antibodies were found in 57 % of pregnant women. Seroprevalence increased with age; 51% of 15- to 19-yr-old women (100 total) had antibodies versus 60% of 20- to 24-yr-old women (127 total). Antibodies to T. gondii (MAT, 1:25 serum dilution) were found in 35% of cats; titers were 1:25 in 7 cats, 1:50 in 4 cats, and 1:500 in 3 cats. Epidemiological data suggested that the ingestion of food or water contaminated with oocysts was an important mode of transmission of T. gondii to women.

Adolescent↗
PubMed2006

Prevalence of Toxoplasma gondii in rats (Rattus norvegicus) in Grenada, West Indies.

Cats are important in the natural epidemiology of Toxoplasma gondii, because they are the only hosts that can excrete environmentally resistant oocysts. Cats are infected with T. gondii via predation on infected birds and rodents. During 2005, 238 rats (Rattus norvegicus) were trapped in Grenada, West Indies, and their sera along with tissue samples from their hearts and brains were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, titer 1:40 or higher); only 2 (0.8%) of 238 rats were found to be infected. Brains and hearts of all rats were bioassayed in mice. Toxoplasma gondii was isolated from the brain and the heart of only 1 rat, which had a MAT titer of 1:320. All of 5 mice inoculated with the heart tissue, and the 5 mice inoculated with the brain tissue of the infected rat remained asymptomatic, even though tissue cysts were found in their brains. Genetically, the isolates of T. gondii from the heart and the brain were identical and had genotype III by using the SAG1, SAG2, SAG3, BTUB, and GRA6 gene markers. These data indicate that rats are not important in the natural history of T. gondii in Grenada.

Agglutination Tests↗
PubMed2006

Eosinophilic meningitis due to Angiostrongylus cantonensis.

Angiostrongylus cantonensis is a nematode parasite that inhabits the pulmonary arteries and heart of rodents. It is one of the causative agents of fatal eosinophilic meningoencephalitis in man. We present five cases of eosinophilic meningitis presumably due to infection with Angiostrongylus cantonensis . All the five patients gave history of ingestion of monitor lizard within ten days of onset of symptoms.

Adult↗
PubMed2005

Isolation, tissue distribution, and molecular characterization of Toxoplasma gondii from chickens in Grenada, West Indies.

The prevalence of Toxoplasma gondii in free-range chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 102 free-range chickens (Gallus domesticus) from Grenada was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 53 (52%) chickens with titers of 1:5 in 6, 1:10 in 4, 1:20 in 4, 1:40 in 4, 1:80 in 15, 1:160 in 9, 1: 320 in 5, 1:640 in 4, and 1:1,280 or greater in 2. Hearts, pectoral muscles, and brains of 43 seropositive chickens with MAT titers of 1:20 or greater were bioassayed individually in mice. Tissues of each of 10 chickens with titers of 1:5 and 1:10 were pooled and bioassayed in mice. Tissues from the remaining 49 seronegative chickens were pooled and fed to 4 T. gondii-free cats. Feces of cats were examined for oocysts; they did not shed oocysts. T. gondii was isolated from 35 of 43 chickens with MAT titers of 1:20 or greater; from the hearts, brains, and pectoral muscles of 2, hearts and brains of 20, from the hearts alone of 11, and brains alone of 2. T. gondii was isolated from 1 of 10 chickens with titers of 1:5 or 1:10. All 36 T. gondii isolates were avirulent for mice. Genotyping of these 36 isolates using polymorphisms at the SAG2 locus indicated that 29 were Type III, 5 were Type I, 1 was Type II, and 1 had both Type I and Type III. Genetically, the isolates from Grenada were different from those from the United States; Type II was the predominant type from the United States. Phenotypically, all isolates from Grenada were avirulent for mice, whereas those from Brazil were mouse-virulent. This is the first report of isolation of T. gondii from chickens from Grenada, West Indies.

Agglutination Tests↗
PubMed2001

Preliminary report on a single-tube, non-interrupted reverse transcription-polymerase chain reaction for the detection of rabies virus in brain tissue.

A simple method for the rapid detection of rabies virus was developed employing a single-tube reverse transcription polymerase chain reaction (RT-PCR). The method utilized a single buffer system for both RT and PCR and was performed without interruption as a single thermal cycling programme. Two primer sets within the genes coding for rabies nucleoprotein and glycoprotein were used to amplify a 533 bp and a 406 bp amplicon, respectively. The amplified products were detected with a challenge virus strain (CVS) of rabies. There was no amplified product with uninfected mouse or dog brain. The method was applied to detect rabies virus in 10 mouse inoculation test (MIT)-positive and three MIT-negative brain tissue samples. The amplified product was found only in the MIT-positive samples. The amplified product was confirmed by restriction endonuclease analysis using Hinf1. The results from RT-PCR correlated well with the results from MIT. This indicates that the single-tube RT-PCR may be a useful method for detecting rabies virus in brain tissue samples from suspected cases of rabies.

Animals↗
PubMed2001

Developmental inhibition and reproductive potential impairment in Musca domestica L. by heavy metals.

Post embryonic development and adult emergence of housefly, M. domestica L. was adversely affected in varying degrees on exposure of larvae to 6 different heavy metals. Of these, salts of mercury, aluminium and cadmium exhibited significant reduction in normal adult emergence. High decline in reproductive potential in terms of female fecundity and egg hatchability was also observed in the F1 progenies of treated larvae. The results are discussed in light of heavy pollution of environment by such contaminants.

Animals↗
PubMed2001

Effects of some trace heavy metals on Poecilia reticulata (Peters).

Three trace heavy metals viz., nickel, copper and zinc were studied for their toxic action against Poecilia retriculata (Peters). Among these, copper was found to be most active followed by zinc and nickel. Accumulations of these metals as well as behavioural studies were carried out after exposing fish to sub-lethal concentration of LC20. It was found that the highest quantity of nickel was accumulated in the fish body followed by zinc and copper. After exposure to sub-lethal concentration of metals some behavioural changes in fish were observed due to stress, such as mucus like secretion over gills, excessive excretion, anoretic condition and increased distance between gills and operculum. In all the cases fin movement was observed. Role and use of such changes as biological indicators or as biological early warning system in water quality assessment has been discussed.

Animals↗
PubMed2000

Apert syndrome variant with overlapping features of Crouzon syndrome.

A rare variant of Apert syndrome having overlapping features of Crouzon syndrome is described. The salient features of the two syndromes are briefly discussed and overlapping features are highlighted. A possible genetic explanation for the same is mentioned.

Acrocephalosyndactylia↗
PubMed2000

The runaway corruption-cynicism syndrome in Asian cultures: its redemption and the future of bioethics.

Corruption has been cynically dismissed as a global phenomenon by some Asian leaders. This attitude becomes a plausible cloak for mala fide deeds. Worse, it becomes a veritable shield for the corrupt. But modern information and investigative systems can penetrate the meticulously built smoke screens and illuminate the murky shadows. Bailouts due to political-economic patronage are, however, routine and considered unworthy of protracted media pursuance, resulting in further cycles of brazen corruption. Public indifference towards the latter is a product of institutional, moral and cultural failures, resulting in corresponding cycles of cynicism. The overall consequence is near total despondence of any meaningful redemption, or overall improvement. In Asia, demographic pressures and/or socio-economic frailities, as also politico-religious bigotry add to the general public disillusion and indifference, and breeds an unending treadmill of further corruption and disgruntled cynicism without much hope for amelioration. The solution, and salvation, lies only in individual and collective (social) espousal of the ethical in every walk, and work, of life. Social, spiritual and cultural pressures enabling political activism in ostracizing both criminal intent and action in public life, maintenance of decorum and propriety in private life by public figures can rekindle hope and confidence, and banish sullen cynicism from the heart and mind of the lay public. In most of Asia this has become an imperative needing urgent attention and implementation, but hardly any silver clouds are yet discernible on any Asian horizon. A sea change in moral perspectives of whole communities only can redeem the situation, and pave the way to a renaissance of the Bioethical culture which, the author asserts, has been an underlying universal ingredient of the Asian psyche through the ages.

Asia↗
PubMed1997

Reactive oxygen species formation in peripheral blood neutrophils in different types of smokers.

The present study was envisaged to assess the state of oxidative metabolism of neutrophils, recovered from smokers (cigarette, beedi, hookah and mixed products) and non-smokers. Superoxide anion (O2.-) production was significantly higher in neutrophils from all groups of smokers (P < 0.001). Total leukocyte count (TLC) was significantly more in symptomatic subjects among the cigarette, hookah and mixed smokers (P < 0.05). Total neutrophil count (TNC) was significantly higher in symptomatic than asymptomatic subjects of hookah and mixed smoking groups (P < 0.05). In the pathogenesis of chronic obstructive pulmonary disease (COPD) in tobacco smokers, the role of leukocytosis, increased neutrophil sequestration into the lung, increased neutrophil toxic oxygen species including superoxide release in the lung may cause direct injury to lung tissues.

Adult↗
PubMed1996

The isolation of peste des petits ruminants virus from northern India.

The aetiological agent responsible for an epizootic of a rinderpest-like disease afflicting sheep and goats in three states of northern India was confirmed as peste des petits ruminants virus. To differentiate the virus from rinderpest a number of diagnostic tests were used, including immunocapture ELISA, specific oligonucleotide primers in a reverse transcriptase polymerase chain reaction, immunofluorescence with virus specific monoclonal antibodies and virus isolation. The virulence profile of one isolate in cattle sheep and goats was established. Infected animals developed specific antibody responses and excreted specific antigen in their lachrymal secretions.

Animals↗
PubMed1996

Detection of Salmonella DNA in chicken embryos and environmental samples by polymerase chain reaction.

By polymerase chain reaction (PCR) using a pair of primers specific for Salmonella phoE gene a 365-bp specific gene fragment could be amplified from yolk of infertile eggs and dead-in-shell chicken embryos, and from environmental samples. Out of 45 dead-in-shell embryo samples, 20 (44.4%) were found positive for Salmonella DNA by PCR compared to 11 (24.4%) by bacteria isolation. Salmonella DNA could also be detected from infertile eggs, chicken faeces, floor litter and chick fluff, which incidence was higher than that by bacteria isolation.

Animals↗
PubMed1996

Laboratory evaluation of toxic baits for mosquito (Aedes aegypti) larvae.

Toxic bait discs were prepared by incorporating the larvicide Abate (Temephos) technical, with yeast and dog biscuit (1:1), the latter forming the attractant source. These were assessed in 1, 10 and 25 litre aquaria and 100 litre drums against Aedes aegypti larvae. Floating as well as sinking bait discs were found equally effective in controlling free moving larvae. Larvae confined in artificially suspended cages were not affected. The baits were found effective for 5 to 6 weeks. Toxic disc bait preparation methodology and evaluation protocols are discussed in this communication.

Aedes↗
PubMed1995

Laboratory evaluation of an ovipositional trap for mosquito adults Aedes aegypti (L.) (Diptera: Culicidae).

A trap was designed, fabricated and evaluated for trapping and killing ovipositing females of the yellow fever mosquito Aedes. aegypti. Water in which larval stages had previously dwelt for 48 hrs. formed the attractant source for ovipositing mosquito females. The trap was evaluated under different experimental conditions. Single choice and double choice experiments were performed with or without glue applied to inner surfaces, to determine trap efficacy. Effect of population size and alteration in assay conditions on percentage catch are discussed.

Adhesives↗
PubMed1995

Effect of some new insect growth regulators on metamorphosis & reproduction of Aedes aegypti.

Fourth instar larvae and pupae of Ae. aegypti were treated with four most active insect growth regulators from a new series of mixed alkyl and aryl diethers based on geraniol. Considerable reduction in fecundity and fertility of adults was obtained. Treatment of pupae or pharate adults did not affect adult emergence. Topical treatment of adult females caused great reduction in fertility and fecundity in older as compared to younger females. In addition to the effects on reproduction, adult survival was also reduced in the treated younger females.

Aedes↗