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Biomedical subjects

N Anand

Publications and source records attributed to N Anand.

At least 73 records · Page 4Linked to original sources
PubMed1988

Susceptibility of glucose-6-phosphate dehydrogenase deficient red cells to primaquine enantiomers and two putative metabolites--I. Effect on reduced glutathione, methemoglobin content and release of hemoglobin.

The effects of the primaquine (PQ) enantiomers, (+)PQ and (-)PQ, and two putative metabolites [5-hydroxyprimaquine (5HPQ) and 6-desmethyl-5-hydroxyprimaquine (6D5HPQ)] on methemoglobin (Met Hb) and glutathione content and release of hemoglobin into plasma from glucose-6-phosphate dehydrogenase (G-6-PD) deficient red cells were studied in vitro. The results show that a 1.5 mM concentration of (-)PQ produced a significantly greater increase in Met Hb content and decrease in reduced glutathione (GSH) level than did (+)PQ. However, the release of plasma hemoglobin was greater with (+)PQ than with (-)PQ. The hydroxy derivatives of primaquine, 5HPQ and 6D5HPQ, were significantly more active than PQ. Their individual effects differed; whereas 5HPQ produced significantly greater reduction in GSH compared to 6D5HPQ, the effect of 6D5HPQ on Met Hb content and release of plasma hemoglobin was greater than that of 5HPQ. The qualitative effects of these compounds on normal, heterozygous and hemizygous G-6-PD deficient red cells were similar, but quantitatively the effects were greatest on hemizygous G-6-PD deficient cells and intermediate on heterozygous cells.

Erythrocytes↗
PubMed1988

Litomosoides carinii in rodents: immunomodulation in potentiating action of diethylcarbamazine.

The antifilarial activity of combination of diethylcarbamazine (DEC) and an immunomodulator, N-Palmitoylmuramyl-L-alanyl-D-isoglutamine (NP-MDP) was evaluated against Litomosoides carinii in cotton rat (Sigmodon hispidus) and Mastomys natalensis. DEC was used at 6 mg/kg in cotton rat whereas it was 75 mg/kg x 5 days in mastomys. The immunomodulator was administered at 62.5 to 500 micrograms/animal x 2 days. Combination therapy with optimum dose of immunomodulator resulted in prolonged and significant suppression of microfilaraemia in comparison to infected animals treated only with DEC. The effective doses of immunomodulator alone or in combination with DEC also caused enhanced antibody titre in treated animals. Though combination therapy resulted in prolonged suppression of microfilaraemia, the effect disappeared slowly and caused no damage to adult worms.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1986

Protection of mice against Plasmodium berghei infection by a tuftsin derivative.

In Plasmodium berghei infections, the mortality rate and parasitaemias were significantly reduced and the mean survival time was considerably enhanced by pretreating the animals with a tuftsin derivative, Thr-Lys-Pro-ARg-NH-(CH2)2-NHCOC15H31. This effect of the modified tuftsin was further increased upon its incorporation in the liposome bilayer. These results indicate that tuftsin and its derivatives may prove useful in enhancing nonspecific host resistance against protozoan infections.

Animals↗
PubMed1986

Enhancement in anti-Semliki Forest virus activity of ds RNA by a muramyl dipeptide.

Antiviral activity of an interferon-inducing mycoviral ds RNA against Semliki Forest virus infection was considerably enhanced by N-palmitoylmuramyl-L-alanyl-D-isoglutamine (PMDP), a new muramyl dipeptide. This enhancement in activity was not due to increased production of interferon, but resulted probably from a PMDP-induced increase in nonspecific resistance to infection. These results indicate that a combined treatment with an interferon inducer and muramyl dipeptide may prove highly useful to control effectively viral infections.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1986

Studies in antifertility agents. 50. Stereoselective binding of d- and l-centchromans to estrogen receptors and their antifertility activity.

Centchroman [dl-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(beta-pyrrolidinoethoxy)phenyl] - 7-methoxychroman hydrochloride], an antifertility agent under clinical evaluation, has been resolved into its optical enantiomers. The cytosol estrogen receptor binding affinity and estrogenic, antiestrogenic and antiimplantation activities of the two enantiomers have been determined. The enantiomers display a 7-fold difference in receptor affinity, and a corresponding difference in stimulation of the uterine growth and antiimplantation activity was observed in rats.

Animals↗
PubMed1984

Studies of potential filaricides: Part 14--Activity of 1-iso-butoxycarbonyl-4-methylpiperazine against experimental filariasis.

The synthesis and filaricidal activity of 1-iso-butoxycarbonyl-4-methylpiperazine against Litomosoides carinii in Sigmodon hispidus and Dipetalonema viteae in Mastomys natalensis is reported. At an intraperitoneal or oral dose of 3 mg/kg given for 6 days, the compound removed 91% of the circulating microfilariae but had no effect on adult L. carinii. However, it killed all microfilariae and adults of D. viteae at a subcutaneous dose of 50 mg/kg given for 6 days. The compound also possessed chemoprophylactic activity against the larvae of L. carinii and D. viteae at a dose of 30 and 50 mg/kg respectively.

Animals↗
PubMed1984

Combined vitrectomy, intraocular microsurgery and liquid silicone in the treatment of proliferative vitreoretinopathy.

This study investigates the effectiveness of combining vitrectomy, scleral buckling, intraocular microsurgery and liquid silicone injection for the treatment of retinal detachment complicated by proliferative vitreoretinopathy: 48 eyes were treated using these techniques combined. Complete attachment was achieved in 16 eyes (33%), partial attachment in 20 eyes (42%), and 12 eyes (25%) remained detached. Vision was improved in 17 eyes (35%), unchanged in 17 eyes (35%), and worse in 14 eyes (30%). Complications included emulsification of the silicone, glaucoma, cataract, band degeneration of the cornea, reproliferation of membranes and passage of silicone into the subretinal space. Significant preservation of mobility vision was achieved. A larger series of patients with longer follow-up will ultimately determine the place of this technique in the management of this complicated problem.

Combined Modality Therapy↗
PubMed1984

Vitreous cytology in primary cerebroretinal malignant lymphoma.

We report the case of a 72-year-old woman who presented with vitreous opacities of unknown cause. A pars plana vitrectomy yielded material in which there were atypical lymphoid cells consistent with malignant lymphoma. Five months after the vitrectomy, the patient re-presented with cerebral lymphoma. Our report emphasizes the value of cytological examination of the vitreous in selected cases. We also review the features of malignant lymphoma of the retina and stress the cerebroretinal axis of involvement in this disease.

Aged↗
PubMed1983

Studies in antifertility agents--Part XLI : Secosteroids--X : Syntheses of various stereoisomers of (+/-) 2,6 beta -diethyl-7 alpha -ethynyl-3-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7 beta-ol.

The syntheses of (+/-) 2 alpha,6 beta -diethyl-7 alpha -ethynyl-3 alpha-(p-hydroxyphenyl)-trans- bicyclo[4.3.0]nonan-7 beta-ol (8), (+/-)2 beta,6 beta-diethyl-7 alpha-ethynyl-3 beta-(p-methoxy-phenyl)-trans-bicyclo[4.3.0]nonan-7 beta-ol 12 and (+/-) 2 alpha,6 beta-diethyl-7 alpha-ethynyl-3 beta-(p-hydroxyphenyl)- trans-bicyclo[4.3.0]nonan-7 beta-ol (18) and their derivatives, which are essentially B-seco-steroids having cis-anti-trans, cis-syn-trans and trans-anti-trans geometries have been carried out. A study of their antiimplantation activities (AI) and receptor binding affinities (RBA) show that trans-anti-trans compounds are biologically most potent, followed by the corresponding cis-anti-trans and cis-syn-trans compounds. The most potent compound 18 is active at 1 mg/kg in rats. Introduction of 7 alpha-ethynyl group increases their AI activity; however, no significant effect on their RBA is observed.

Animals↗
PubMed1983

Antifertility agents. 38. Effect of the side chain and its position on the activity of 3,4-diarylchromans.

In a study of the effect of the substituent on the receptor binding affinity (RBA), estrogenicity, and antiimplantation (AI) activity in trans-3,4-diarylchromans, it has been found that demethylation of trans-2, 2-dimethyl-3-phenyl-4-[p-(beta-pyrrolidinoethoxy)phenyl]-7-methoxychroman (centchroman, 1) to the corresponding 7-hydroxy compound (7) results in a 20-fold increase in RBA (112%) without any appreciable change in AI activity. On the other hand, absence of the pyrrolidinoethyl group from the 4-phenyl residue (6) leads to a drop in both RBA and AI activity. A chain length of two to three carbon atoms and a pyrrolidino ring appear to be necessary for activity in these compounds. It has been found that while the trans isomers with the tertiary aminoalkoxy side chain in the para position of the 4-phenyl radical were the most active, in the corresponding cis-chromans and chromenes, analogues with this chain in the meta position were most active; the ortho substituted compounds of all these series were inactive. In 3-phenyl-substituted compounds, the trans isomer carrying the p-hydroxy substituent (33) was found to be the most active; the corresponding pyrrolidinoethyl ether (13) showed a lower order of activity. The implication of these observations on the mapping of the different subsites on the receptor has been discussed.

Animals↗
PubMed1979

Neuroleptic receptors: stereoselectivity for neuroleptic enantiomers.

In order to identify a pair of neuroleptic enantiomers with the highest stereoselective interaction with neuroleptic/dopamine receptors, the effects of eight pairs of neuroleptic enantiomers were tested on the specific binding of 3H-spiperone to crude homogenates of calf caudate nucleus. The ratios of the Ki values were: (+)-butaclamol/(-)-butaclamol = 3000; dexclamol/(-)-analogue = 151; (+)-isobutaclamol/(-)-isobutaclamol = 146; (-)-CTC/(+)-CTC= 109; (-)-centbutindole/(+)-centbutindole = 20; S(+)-octoclothepin/R(-)-octoclothepin = 11. Thus, the neuroleptic receptor is highly stereoselective for the rigid butaclamol derivatives, but much less so for the flexible neuroleptics. The 3H-apomorphine binding site, however, had a stereoselectivity ratio of only 7 for isobutaclamol, further suggesting that the high affinity sites (i.e. nM) for 3H-neuroleptic binding and for 3H-apomorphine binding are different.

Animals↗