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Biomedical subjects

V P Sharma

Publications and source records attributed to V P Sharma.

At least 145 records · Page 8Linked to original sources
PubMed1993

Use of kerosene lamp containing synthetic pyrethroids to repel mosquitoes.

An indigenous and appropriate method of personal protection was developed and tested in rural areas. It consists of an ordinary kerosene lamp made of tin with a regulator to adjust the wick. Different concentrations of esbiothrin, a synthetic pyrethroid, were mixed in kerosene and allowed to burn in living rooms and cattlesheds from dusk to dawn to observe hourly entry of mosquitoes. The tin lamp (100 ml capacity) without chimney provided the most efficient protection from mosquito bites. The protection varied from 84.2 +/- 8.2 to 97.8 +/- 2.8. Maximum protection was observed against An. culicifacies. Esbiothrin kerosene lamp (0.01%) lighted in living room provided 99.7% protection to exposed human baits seated at a distance of 1 m from the lamp. The technique is simple, cost-effective and does not require electricity and can be used both for illumination and repelling mosquitoes in remote and inaccesible areas.

Allethrins↗
PubMed1993

Inheritance and linkage of malic enzyme in Anopheles stephensi.

Genetics and linkage analysis of malic enzyme (Me) have been worked out in Anopheles stephensi. Genetic analysis revealed the 2 variants to be codominant alleles at a locus Me, which is sex-linked. Linkage studies with another X-linked mutant red-eye (r), indicated that the map distance between 2 loci was 44.60 +/- 1.07.

Animals↗
PubMed1993

Mosquito repellent action of neem (Azadirachta indica) oil.

Two percent neem oil mixed in coconut oil, when applied to the exposed body parts of human volunteers, provided complete protection for 12 h from the bites of all anopheline species. Application of neem oil is safe and can be used for protection from malaria in endemic countries.

Animals↗
PubMed1993

Neem oil as a sand fly (Diptera: Psychodidae) repellent.

The repellent action of neem oil was evaluated against sand flies under laboratory and field conditions. Concentrations of 2% neem oil mixed in coconut or mustard oil provided 100% protection against Phlebotomus argentipes throughout the night under field conditions; against Phlebotomus papatasi it repelled sand flies for about 7 h in the laboratory. Neem oil is an indigenous product and a low-cost alternative for personal protection against sand fly bites.

Animals↗
PubMed1993

In-vivo and in-vitro sensitivity of Plasmodium falciparum to chloroquine at Indian Oil Corporation, Mathura (U.P.).

In vivo and in vitro susceptibility of Plasmodium falciparum to chloroquine were conducted at Indian Oil Corporation (IOC), Mathura, India. 18 out of 31 cases showed resistance [minimum inhibitory concentration (MIC) 8 pmol] in in vitro study. EC50 and EC90 values estimated from log-probit analysis for resistant isolates were 0.66 and 1.44 microM/litre, and for sensitive isolates 0.28 and 0.96 microM/litre blood respectively. In vivo tests identified 13 cases (40.62%) as resistant and 19 cases (59.73%) as sensitive out of 32 cases. All the cases belonged to IOC, Mathura complex, or its vicinity.

Animals↗
PubMed1993

Laboratory and field evaluation of Spherix, a formulation of Bacillus sphaericus (B-101), to control breeding of Anopheles stephensi and Culex quinquefasciatus.

Spherix, a powder formulation of Bacillus sphaericus strain B-101, serotype H5a 5b, was evaluated against larvae of Anopheles stephensi and Culex quinquefasciatus in both the laboratory and field. In laboratory tests the formulation @ 0.1 g/sq m produced 100% mortality against larvae of both mosquito species at room temperature (28-32 degrees C). The larvicidal activity of Spherix against An. stephensi @ 0.5 g/sq m persisted for over 12 weeks under laboratory conditions. Field evaluation of Spherix @ 0.25-2.0 g/sq m produced 95-100% reduction in the larval density of both An. stephensi and Culex quinquefasciatus within 48 h in different habitats, and the larvicidal activity persisted for 2-4 weeks in water habitats.

Animals↗
PubMed1993

Anopheles culicifacies complex: cytogenetic characterization of Rameshwaram island populations.

Anopheles culicifacies sensu lato collected from Rameshwaram island, Tamil Nadu state, India was identified as species B based on the diagnostic inversion karyotype Xab 2g1+h1 as observed in polytene chromosomes. Among male mitotic karyotypes made from larval neurogonial cells, two types were observed: one with an acrocentric Y-chromosome and the other with a sub-metacentric Y-chromosome, both had sub-metacentric X and metacentric autosomes. The Rameshwaram population is identical to species B in its genetic relationship with species A and C as determined by experimental hybridizations (sterile and fertile male hybrids, respectively).

Animals↗
PubMed1993

Biomechanical evaluation of bonding with glass ionomer cement.

This study was designed to determine the bond strength of three commercially available glass ionomer cements when used to bond mesh-backed medium twin standard edgewise (.022" x .028") brackets to enamel surface. The bond strength of one composite resin was compared with those of the glass ionomer cements. Scanning electron microscopic study of the debonded enamel surface was carried out to evaluate the effects of the bonding agents on enamel. The teeth were bonded with all the materials according to manufacturers' specifications. Each specimen was embedded in Dental stone with the bonded facial surface exposed. A special bracket holder was used to hold the brackets precisely under the wings during debonding. An Instron universal testing machine was used to measure the force required for bond failure. To simulate oral conditions, the direction of pull was so designed that it included an element of torsional stress along with tensile force. The findings indicate that Ketac-cem and Fuji II Glass ionomer cements hae adequate bond strength for clinical use. The scanning electron photomicrographs revealed that the enamel was least affected and well preserved in the Glass ionomer cement group. Further investigation is required to test the bond strengths of Glass ionomer cements clinically.

Biomechanical Phenomena↗
PubMed1992

Assignment of 6-phosphogluconate dehydrogenase and malate dehydrogenase to chromosome 3 of Anopheles stephensi.

Genetics and linkage analysis of 6-phosphogluconate dehydrogenase (6-PGD) and malate dehydrogenase (MDH) have been investigated in Anopheles stephensi. Both these markers were found to be autosomal and linked and have been assigned to linkage group III. Two mutant markers, Black larva (Bl) and golden-yellow larva (gy), were used to establish the map distances, and the current sequence of loci on chromosome 3 is as follows: Bl (3.75)-gy (14.53)-Mdh-2 (49.83)-6-pgd.

Animals↗
PubMed1992

Differential selection of malathion resistance in Anopheles culicifacies A and B (Diptera: Culicidae) in Haryana State, India.

In November 1989, for the first time after the introduction of malathion spray in 1982, increased densities of Anopheles culicifacies Giles s.l. were observed in Chhatera and Barota, two villages in Halalpur block in Sonepat District, Haryana State, India. In bioassay tests against the diagnostic dose of malathion (5% for 1 h), 41-47% of mosquitoes survived. An culicifacies populations in this area comprise two sibling species, A and B. Differential malathion resistance was observed; in species A it was 2-9% and in species B 62-66%. Likewise, species A was found to be more susceptible to DDT than was species B. The possible use of DDT spray to delay the onset of malathion resistance is discussed.

Animals↗
PubMed1992

Esbiothrin-impregnated ropes as mosquito repellent.

Esbiothrin [(+/-)-3-allyl-2-methyl-4-oxocylopent-2-enyl-(+)-trans- chrysanthemate] is an improved isomeric composition of allethrin series and consists essentially of esters of chrysanthemic acid and allethrolone. Jute rope was impregnated with esbiothrin and the smoke from smouldering ropes was evaluated as mosquito repellent in human dwellings and cattlesheds with open doors and windows at different dosages. Esbiothrin-impregranted (500 ppm) ropes prevented the entry of more than 95% An. culicifacles and other anophelines, 90.9-88.8% Culex quinquefasciatus and 96-95.1% total mosquitoes in open rooms of houses and cattlesheds respectively. The impact of ropes was more pronounced on the biting rate of mosquitoes. Indoors and outdoors human baits seated at a distance of about 3 m from smouldering esbiothrin ropes experienced no bite at all from An. culicifacies. An iron mesh around the rope prevents fire hazards.

Allethrins↗
PubMed1992

Sensitivity status of Plasmodium falciparum to chloroquine, amodiaquine, quinine, mefloquine and sulfadoxine/pyrimethamine in a tribal population of District Sundargarh, Orissa.

In a malaria-endemic area of Orissa, wherein chloroquine has been in use for over thirty years, 58.3% (14/24) P. falciparum cases did not respond to single dose chloroquine (10 mg base/kg) in in-vivo test. With standard dose (25 mg base/kg) 31.2% cases (10/32) showed resistance, i.e. at RI (15.6%), RII (9.4%) and RIII (6.2%) levels. Standard dose was superior in response to the single dose therapy [p < 0.05; chi 2 (df 1) = 4.11]. Out of eight isolates tested in vitro, two showed resistance to chloroquine, five to sulfadoxine/pyrimethamine (SP) but all were sensitive to amodiaquine, quinine and mefloquine. Whereas the standard dose of chloroquine would be a better option in general, in resistant cases, SP, quinine and mefloquine offer an alternative drug choice. The implications of drug resistance in a malaria-control programme and the need to revise drug policy in India are discussed.

Amodiaquine↗
PubMed1992

Fishes of District Sundargarh, Orissa, with special reference to their potential in mosquito control.

An extensive fish fauna survey was carried out in Sundargarh, a malaria-endemic district in Orissa, during 1988 to 1990 to identify and evaluate the indigenous larvivorous fishes for mosquito control. In all, 57 species belonging to 19 families under 6 orders were found in the local water bodies. On laboratory evaluation against anopheline and culicine larvae, six potential larvivorous fishes, viz. Aplocheilus panchax, Oryzias melastigma, Oreochromis mossambicus, Gambusia affinis, Danio (B.) rerio and Esomus danricus were selected. Feasibility of mass multiplication of these fishes in village ponds for operational use is being studied.

Animals↗
PubMed1992

Gambusia affinis: dispersal due to floods and its failure to colonize new water bodies in Shahjahanpur District (U.P.).

In villages of District Shahjahanpur, 122 decentralized Gambusia multiplication ponds were established to cover the need of the entire district. Profuse breeding of Gambusia was observed in these ponds. The fishes are being successfully used in mosquito control all over the district. In July 1990 there was a widespread flood due to which 70 Gambusia multiplication ponds were affected and the fish was washed away in large numbers, leaving only a scanty population in the flood-affected ponds. We utilized this opportunity to study the natural dispersal and colonization of Gambusia in different aquatic habitats. The study revealed that Gambusia was either not found in most habitats or was present in very small numbers, and on its own Gambusia was unable to eliminate the local fauna to become a dominant species. Predatory fishes and birds played a major role in eliminating Gambusia. Gambusia is therefore unlikely to pose any ecological hazard in vector-control programmes.

Animals↗
PubMed1992

Biochemical and pathological changes in response to hyperoxia and protection by antioxidants in rats.

A significant decrease in blood haemoglobin, reduced glutathione and protein in lung and liver, without any change in blood reduced glutathione, was observed in rats exposed to 80% oxygen. Hydrogen peroxide induced erythrocyte haemolysis was significantly increased following exposure to hyperoxia. The lungs of rats exposed to hyperoxia showed perivascular edema. Simultaneous treatment with antioxidants, vitamin A, C, or E, protected the animals against oxygen toxicity.

Animals↗