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Biomedical subjects

R Bajpai

Publications and source records attributed to R Bajpai.

29 records · Page 2Linked to original sources
PubMed1989

Pharmacology of alpha/beta arteether--a potential antimalarial drug.

Pharmacological studies on alpha/beta arteether (a 30:70 mixture of isomers), a potential drug for the treatment of cerebral malaria, were carried out in experimental animals by giving the drug in arachis oil suspension. The compound appears to be devoid of significant pharmacological activity on the central nervous, cardiovascular and urinary systems. It lacks an anti-inflammatory response in rats up to 50 mg/kg intramuscularly but at 50-200 mg/kg it has some antianaphylactic potential.

Animals↗
PubMed1989

Artemisinin (qinghaosu)--a new gametocytocidal drug for malaria.

Gametocytocidal activity of artemisinin (qinghaosu) has been demonstrated against simian malaria parasite Plasmodium cynomolgi B. Colony-bred Anopheles stephensi were allowed to feed on gametocyte-carrying rhesus monkeys and the mosquito infectivity rate and oocyst count of the infected mosquito gut were recorded on day 8-9 postinfection. Control (pretreatment) feedings of mosquito on gametocyte-carrying monkeys showed good infectivity in different batches of the mosquitoes ranging from 57.14 to 95.0%. Administration of single intramuscular injection of 5 mg/kg artemisinin (suspended in neutralised oil) resulted in complete loss of mosquito infectivity within 24 h of drug administration. This is the first report on the possible use of artemisinin to stop malaria transmission. The drug has no sporontocidal action.

Animals↗
PubMedDate not supplied

Comparison of antimalarial efficacy of artemisinin (qinghaosu) and arteether against Plasmodium cynomolgi B infection in monkeys.

Arteether (30:70 mixture of alpha and beta epimers) used as injectable intramuscular preparation (in neutralized ground-nut oil) had curative action at 5 mg/kg x 3 d against blood-induced Plasmodium cynomolgi B infection in rhesus monkeys, while the curative dose of artemisinin (qinghaosu) oil suspension was 10 mg/kg x 7 d or 20 mg/kg x 3 d. Parasite clearance with arteether was achieved within 24 h. Neither arteether nor artemisinin exhibited any causal prophylactic or radical curative action up to dose levels of 20 mg/kg against sporozoite-induced P. cynomolgi B infection in rhesus monkeys.

Animals↗
PubMedDate not supplied

Antimalarial efficacy of arteether against multiple drug resistant strain of Plasmodium yoelii nigeriensis.

New quick-acting blood schizontocides are needed to contain the spread of multiple drug resistant strains of P. falciparum and for the treatment of the cerebral malaria cases. A multiple drug resistant strain of P. yoelii nigeriensis resistant to mefloquine (128 mg/kg x 6 days), quinine (300 mg/kg x 7 days) and chloroquine (64 mg/kg x 8 days) was found to be completely susceptible to arteether (a 30:70 mixture of alpha and beta enantiomers) and a dose of 5 mg/kg x 3 days by i.m. route was curative in Swiss mice. Artemisinin at 50 mg/kg x 7 days had only suppressive action against this strain.

Animals↗
PubMedDate not supplied

Reaction of pulmonary macrophages exposed to nickel and cadmium in vitro.

We examined the morphological and functional characteristics of goat alveolar macrophages exposed in a serum-free medium in vitro for up to 20 hr to cadmium as CdCl2 and nickel as NiCl2. The concentration of these metals varied from 0.04 to 1.00 mM. Cadmium reduced the viability and phagocytosis of macrophages and increased the release of lactate dehydrogenase from cells into the culture medium at all the concentrations tested. Alterations in macrophage surface morphology, evaluated by scanning electron microscopy, consisted of withdrawal of pseudopodia and rounding of cells exposed to 0.20 and 1.00 mM of CdCl2. In nickel-exposed macrophages these changes were marked only at higher concentrations of the metal. Higher concentrations of Ni were necessary to produce effects similar to those produced by lower Cd concentrations. Our results demonstrated that the higher toxicity of cadmium as compared to that of nickel for alveolar macrophages is related to a difference in the alterations in the morphology and function of the exposed cells.

Animals↗
PubMedDate not supplied

A carbon-limited medium for growth and sporulation of Bacillus thuringiensis var. kurstaki.

A culture medium for batch production of d-endotoxin by Bacillus thuringiensis (B., t.) has been modified. Through batch and continuous cultivation studies, the original medium was diagnosed to be limited in organic nitrogen. Corn steep liquor was found to be an excellent source for the organic nitrogen and its addition resulted in a carbon limited medium and in a significant increase in the amount of spore-toxin complex formed in shake flasks. Results of bioassay, conducted on Trichoplusia ni, suggest enhancement of larvicidal efficacy under carbon-limited growth conditions.

Ammonium Sulfate↗