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Biomedical subjects

R N Sharma

Publications and source records attributed to R N Sharma.

At least 37 records · Page 2Linked to original sources
PubMed1995

Laboratory and field evaluation of an insecticidal trap for houseflies.

Several substances/food baits and admixtures thereof were tested in a perspex trap, treated with insecticide K-othrine@0.01 mg/cm2. Bioefficacy for housefly trapping was evaluated. Combination of ingredients was found to be more effective than individual ingredients. A combination of some easily available and cheap ingredients were employed for field trials. The admixtures of milk powder, dog biscuit, jaggery and banana peeling was found very effective. The trap efficacy including persistence of the toxicant K-othrine was observed for more than 6 months. Observations on number of flies trapped and utility of such a trap in actual field situation are discussed.

Animals↗
PubMed1995

Spontaneous lesions in the thyroid of sheep and goats in Iran.

A slaughterhouse survey conducted in Ahwaz (Iran) revealed higher incidence of pathological lesions in the thyroid glands of goats (6.54%) than in sheep (2.8%). Goitre was found in 4.99% and 1.96% of slaughtered goats and sheep, respectively. However, ultimobranchial body cysts were present three times more in sheep than in goats.

Animals↗
PubMed1994

Indeterminate leprosy: a seroimmunological and histochemical evaluation.

An effort was made to differentiate indeterminate (IND) leprosy from other types of the paucibacillary (PB) group of leprosy and to identify among indeterminate leprosy cases those which may evolve to multibacillary (MB) leprosy, using serological, immunological and histochemical parameters. A total of 92 untreated, histologically classified (TT-19, BT-30, IND-32) patients, including 11 cases diagnosed as nonspecific dermatitis (NSD), which were clinically strongly suspected to be leprotic, were screened for antibodies against PGL-I, 35-kDa and LAM antigens. Lepromin tests and antigen demonstration in tissue by indirect immunoperoxidase staining were also carried out. Though a qualitative analysis did not differentiate, a quantitative analysis in terms of a cumulative index (CI) showed a higher antibody level amongst the indeterminate group of patients than the other groups included in PB leprosy. Also, the lepromin negative indeterminate group patients showed a higher CI than the lepromin positive cases, indicating that perhaps these may be the cases which may develop into MB leprosy. Thus, the semiquantification of antibody levels in the form of a CI may be a useful parameter to predict the possible evolution of a given case of indeterminate leprosy. Interestingly 64% of NSD cases had either antigen or antibody which indicated that they were probably cases of leprosy.

Antigens, Bacterial↗
PubMed1994

A device for monitoring and control of mosquitoes by behaviour manipulation.

A trap was designed and fabricated for capturing mosquito larvae based on their behavioural responses to food and light. The larvae upon entering the trap died ultimately due to asphyxiation. Maximum success was achieved with Aedes aegypti larvae in lesser water volumes. The usefulness of the device for studying the response of mosquito larvae and aquatic organisms to chemicals, baits, light, various stimuli and possible pest/vector monitoring and management in aquatic eco-system is discussed.

Aedes↗
PubMed1994

Comparative repellent properties of certain chemicals against mosquitoes, house flies and cockroaches using modified techniques.

Several terpenoids were assessed for their repellent/toxic properties against mosquitoes (Aedes aegypti), house flies (Musca domestica) and cockroaches (Periplaneta americana). Impregnated wide mesh netting was used in the case of the Dipterans, while treated filtered paper was employed for the bioassays with cockroaches. Persistence of the repellent chemicals was studied. Doses ranged from 5-20 gm/M2 for the Dipterans and 25-100 mg per 4 x 4 cm filter paper for the cockroaches. Dimethyl phthalate (DMP) offered the maximum protection of the chemicals tested against mosquitoes but was not so effective against house flies and cockroaches. Citral and Eugenol were effective against all the three test insects. Other test compounds afforded varying degrees of protection. Application strategy and utility of the findings are discussed.

Animals↗
PubMed1994

Toxicity of newly synthesized pyrethroids against the yellow fever mosquito larvae, Aedes aegypti (Diptera: Culicidae).

Synthesis of p-substituted benzyl esters of (+/-) cis 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane-carboxylic acid has been reported. (+/-) cis Dichlorovinyl acid esters of p-substituted phenols acquired insecticidal activity after introduction of methylene group. The insecticidal activity shown against mosquito larvae A. aegypti by compounds having electron withdrawing groups such as -NO2, -CN was substantially higher than that of the compounds having electron-donating groups such as -CH3, -OCH3.

Aedes↗
PubMed1993

Immunodiagnosis of dracunculiasis by dot-ELISA.

A dot-enzyme-linked immunosorbent assay (dot-ELISA) using soluble adult-guineaworm antigen was developed for immunodiagnosis of Dracunculus medinensis infection. The test was found to be specific and sensitive when compared with ELISA. The dot-ELISA described here was found to be time-saving and easy to perform, and its possible use as a diagnostic and epidemiological tool under field conditions is therefore discussed.

Animals↗
PubMed1993

Serological response of leprosy patients to Mycobacterium leprae specific and mycobacteria specific antigens: possibility of using these assays in combinations.

The serological response of 147 leprosy patients to 3 mycobacterial antigens, PGL-I, 35 kDa (Mycobacterium leprae-specific) and LAM (which is a common mycobacterial antigen) were analysed. A stronger serological response was seen amongst the MB patients than the PB patients in all the assays. The 3 antibody levels correlated positively with each other in both MB and PB cases. An overlap of seropositivity was seen between anti-PGL-I and anti-LAM (p > 0.05). A progressive increase in seropositivity and a significant difference of absorbance or titre in antibody levels in all 3 assays over increasing grades of BI were seen in the MB patients (p < 0.05). A significant difference in seropositivity between untreated and treated groups of patients was observed for anti PGL-I (p < 0.05) and antiLAM (p < 0.01) antibodies. The sensitivity, specificity and efficiency of antiPGL-I (50%; 99%; 70%), antiLAM (43%; 95%; 64%) and anti35 kDa (66%; 100%; 80%) assays taken individually were less than that of combinations of antiPGL-I/anti-35 kDa (74%; 99%; 84%) or antiPGL-I/anti-35 kDa/antiLAM (80%; 94%; 86%). The difference in the efficiency of both sets of combination of assays were not statistically significant (p > 0.05).

Antibodies, Bacterial↗
PubMed1993

Action of some new insect growth regulators on mosquito vectors. Part II: Geraniol based diethers.

Biological activity of saturated diethers viz. 1-benzyloxy/phenoxy-8-alkoxy and 1-alkoxy-8-benzyloxy-3,7-dimethyl-1, 8-octanes (IIa-IIq) prepared from Geraniol, were studied on three mosquito species and the bug Dysdercus koenigii. These diethers exhibited oviposition deterrent and developmental inhibition activities of greater magnitudes than the compounds based on citronellol reported in Part I of this paper. Some of these new compounds inhibit development of mosquitoes at 0.05 ppm and deter oviposition at 0.05 per cent doses. Tests were extended to field simulated conditions in selected cases.

Acyclic Monoterpenes↗
PubMed1993

An apparatus for the experimental demonstration of behavioural responses of the cyclopoid copepod, Mesocyclops leuckarti sensu lato to light and temperature.

To demonstrate the behavioural responses of Mesocyclops leuckarti sensu lato to light and temperature, an apparatus was designed and fabricated. It was found that light did not effect the orientational response significantly (p > 0.05) compared to the control. However, temperature gradient definitely influenced the orientational response (p < 0.05). The suitability of this apparatus for studying the behavioural response of other aquatic organisms are also discussed.

Animals↗
PubMed1993

Vapour toxicity & repellence of some essential oils & terpenoids to adults of Aedes aegypti (L) (Diptera: Culicidae).

Bioefficacy of commercially used synthetic insecticides/repellents and potential of selected essential oils and terpenoids were assessed against mosquitoes. Essential oils and terpenoids, were vapourised in commercially manufactured mosquito repellent electronic assemblies and effects of such vapours were tested on 6-7 days old adult female Aedes aegypti. Commercially available 'mats' (coir rectangles) impregnated with allethrin were used as standards for comparison of Kt50 and Kt90 values. Fastest knock-down was seen in case of allethrin, followed by terpeneol (anhydrous) and (-) carvone. Maximum knock-down time was observed for beta citronellol. All compounds exhibited a repellent effect also, terpeneol (anhydrous) being the best, followed by (-) carvone and citronellal. In repellent tests, no mortality was caused by terpenoids, but allethrin caused > 80 per cent knock-down.

Aedes↗
PubMed1992

The effect of rapamycin on kidney function in the Sprague-Dawley rat.

The effects of rapamycin (RAPA) on kidney function and histology were investigated in the Sprague-Dawley rat and compared with cyclosporine. Drugs were administered orally in a Cremophor-ethanol formulation for 14 days in two separate studies. RAPA, at 1 mg/kg, had no effect either functionally or histologically on the kidney. At 10 mg/kg, RAPA depressed the gain in body weight by 20% in the rat but had only minor functional disturbances on urine output, plasma creatinine, and creatinine clearance in the kidney. It did not induce any histomorphologic abnormalities. CsA, at 25 mg/kg, produced functional alterations in the kidney including elevated plasma creatinine and depressed clearance of creatinine as well as depressed body weight gain (17%). Histologically, CsA induced proximal tubule damage. These results demonstrate that RAPA (10 mg/kg) does not produce nephrotoxicity in the Sprague-Dawley rat at doses three times higher than its effective immunosuppressive doses established in the rat.

Animals↗
PubMed1992

Mosquito repellent activity of oils from Vitex negundo Linn. leaves.

Oil obtained from stream distillate of V. negundo leaves was fractionated by column chromatography. Mosquito repellence activity, as evaluated against Aedes aegypti was mainly confined to the most polar fractions. The protection period against mosquito bites by polar fractions ranged between 1-3 h. However, the mean protection period values of these fractions did not show significant increase in the subsequent subfractions.

Aedes↗
PubMed1991

Action of some insect growth regulators on mosquito vectors: Part I--Citronellol based diethers.

New series of compounds starting from common terpenoids (Geraniol, citronellol) have been examined for biological activity on mosquito larvae. Many of these exhibited development disruption on eggs as well larvae. Some also affected adult oviposition behaviour. Developmental disturbances were classified as JH type by inducing typical metamorphosis inhibition in Dysdercus koenigii in the standard Hemipteran JH bioassay. Where indicated simulated field trials were also undertaken. This report describes results of bioevaluation of the citronellol based compounds. The results indicate that these show multifarious activity against mosquitoes but at relatively high doses, suggesting that exploration of further structural variety is needed before truly promising analogues can be obtained.

Acyclic Monoterpenes↗
PubMed1991

Effect of selected chemicals on mosquito larval orientation behaviour using a new apparatus.

An apparatus was designed and fabricated for studying the effects of aromatic chemicals on the IV instar larvae of Aedes aegypti (L.). The test chemicals (essential oils and monoterpenoids) were incorporated in agar along with yeast and dog biscuits which formed an attractant food source (bait). A fairly rapid decrease in the migration of larvae towards the bait cum chemical source was observed during the first hour after which a steady state was observed. Minimum migration (9.67%) was seen with terpeneol anhydrous and maximum (15.0%) with beta-citronellal as compared to control (65.67%), at the end of a 4 hr exposure period. Food particles were also detected on microscopic examination.

Aedes↗
PubMed1990

An outbreak of gizzard erosion and ulceration in chicks in Zambia.

An outbreak of gizzard erosion and ulceration in broilers in Zambia is described. Approximately 100,000 chickens in the age group of 2-9 weeks were affected. Mortality ranged from 5 to 30%. In a majority of cases, crops, oesophaguses and gizzards were engorged with dark brown to black watery material. Lesions were mainly in the gizzard comprising erosions and ulcers. High levels of fish meal in the ration is indicated as a causative factor.

Animals↗
PubMed1990

Effect of azadirachtin on Mesocyclops leuckarti sensu lato, vector of dracunculiasis.

Extension or otherwise of characteristic insect development inhibitory effects of the neem sesquiterpenoid azadirachtin have been examined on eggs and nauplii of the crustacean cyclops, M. leuckarti sensu lato, a major vector of guineaworm disease at 0.1 ppm and above doses. Azadirachtin reduced survival of early nauplii (N1 to N3) at 0.1 ppm and above doses. No such effect was observed when eggs and late nauplii (N4 to N5) were exposed. Azadirachtin did not affect the moult cycle when late nauplii (N4 to N5) were exposed continuously till adulthood. At all concentrations tested, adult cyclops exhibited normal mating.

Animals↗