Showing papers by "Central Drug Research Institute published in 1982"

Role of uteroglobin and transglutaminase in masking the antigenicity of implanting rabbit embryos.

Abstract: Using rabbit as a model, the roles of uteroglobin (UG) and transglutaminase (TG) in masking the antigenicity of early developing mammalian embryo have been investigated. Maternal lymphocytes in vitro, when mixed with mitomycin-C inactivated blastomeres, incorporated H3-thymidine, suggesting recognition of embryonic antigens by these cells. However, pretreatment of blastomeres with pregnant uterine fluid (PUF) or with UG alone or in combination with TG (coagulation factor XIIIa), resulted in a significant and dose-dependent suppression of H3-thymidine incorporation into these lymphocytes. A complete suppression was achieved at a concentration of 250 micrograms of UG/ml, in the absence of TG. However, in the presence of TG, only 1.0 micrograms of UG/ml was required for total suppression. Neither nonpregnant uterine fluid (NPUF), nor myoglobin, a nonspecific protein similar in molecular weight to UG, had any suppressive effect. Incubation of uteroglobin with anti-UG or TG with its antiserum prior to the pretreatment of blastomeres eliminated the suppressive effect of these proteins. Inhibition of TG by neopentyl chloroethyl nitrosourea (NPCNU) also eliminated the suppressive effects of uteroglobin on H3-thymidine incorporation into maternal lymphocytes. These results suggest that in the pregnant uterus UG in conjunction with TG may play a specific role in masking the antigenicity of developing embryos during implantation.

A new look at nonparasitized red cells of malaria-infected monkeys.

Abstract: Many reports have shown that malarial parasites can produce distinct morphological and molecular alterations in the membranes of the parasitized erythrocytes1–8, but few studies have been carried out on nonparasitized erythrocytes of infected animals9–11. We report here that the outer leaflet of the membrane bilayer of nonparasitized erythrocytes contains significantly larger amounts of aminophospholipids (phos-phatidylethanolamine (PE) and phosphatidylserine (PS)), than the normal red cell membrane. This alteration in nonparasitized red cells is probably caused by Ca2+-induced cross-linking of spectrin, and gradually disappears after chloroquine treatment. The external localization of PS in these cells together with defective structure of their cytoskeletal network provide a strong basis for the complications associated with malaria infection like thrombosis, infarction and severe anaemia.

Scanning electron microscopic observations on the tegumental surfaces of two rumen flukes (Trematoda: Paramphistomata)

Abstract: The surface microtopography of Calicophoron papillosum (Stiles & Goldberger) and C. calicophorum (Fischoeder), inhabiting the rumen of sheep, has been studied by SEM. In C. papillosum, conspicuous transverse ridges encircle the mid-body, gradually lessening dorsally towards the posterior end. The general body surface is aspinose and smooth except for minute bead-like tubercles in the circumoral area. Two types of putative sensory structures—domed aciliate papillae and tegumental pits—are present. Their characteristic aggregation in certain regions and their distribution in other parts of the body is described. A unique pattern of ridges, confined only to the base of the genital papilla and the genital atrium, has been observed. In C. calicophorum, tegumental folds encircle the body, these are more numerous near the anterior end and fewer posteriorly. The oral area has numerous concentric folds with domed aciliate papillae; between or on the papillae are tegumental elevated pits from the centre of which a knob-like structure protrudes. These sensory structures occur to a lesser extent in the acctabular area.

Analysis of histamine receptors in the central thermoregulatory mechanism of Mastomys natalensis.

Abstract: 1 The effect of intracerebroventricular (i.c.v.) injection of histamine on the rectal temperature of Mastomys natalensis at ambient temperatures of 10, 24 and 33 degrees C has been studied. 2 Low doses (0.1-1.0 microgram) of histamine produced hypothermia while larger doses (5-20 micrograms) produced dose-dependent hyperthermia. The hypothermic effect was significantly antagonized by mepyramine while the hyperthermia was blocked by cimetidine. 3 Histamine H1-receptor agonists, 2-methyl-histamine and 2-pyridyl-ethylamine, also produced hypothermia which could be blocked by mepyramine. 4 Histamine H2-receptor agonists, impromidine and dimaprit, produced hyperthermia which was antagonized by cimetidine. 5 Pretreatment of the animals with a beta-adrenoceptor antagonist, MJ1999, did not affect the response to histamine. 6 The hyperthermic effect of histamine (10 micrograms) was most marked at 10 degrees C and was attenuated at 33 degrees C. 7 It is concluded that both H1 and H2-histamine receptors are present in the brain of Mastomys. The H1-receptors mediate hypothermia and H2-receptors hyperthermia.

3, 5-Dibromo-2'-chloro-4'-isothiocyanatosalicylanilide, a potent anthelmintic.

Abstract: The compound, 3, 5-dibromo-2'-chloro-4'-isothiocyanatosalicylanilide, has been tested against various nematode and cestode parasites in experimental and domestic animals. It shoved 100% activity against Ancylostoma ceylanicum, A tubaeformis, Syphacia obvelata, ascaridia galli, Toxocara spp., Toxascaris sp., Gnathostoma spinigerum, Hymenolepis nana, Raillietina spp. and Taenia spp. in doses 25-70 mg/kg given in single or multiple administrations.

Antibiotics in the chemotherapy of malaria

Abstract: During the last three decades considerable progress has been made in the field of chemotherapy of malaria and several comprehensive books and reviews on this subject, particularly dealing with the use of antimalarial drugs in the control of malaria, have been published [1–7]. The chemotherapy of malaria involves the development of new chemotherapeutic agents as well as evaluation of existing ones for (1) causal chemoprophylaxis, (2) blood schizontocidal activity, (3) tissue schizontocidal activity (or anti-relapse drugs), (4) gametocytocidal activity to stop transmission and (5) sporontocidal activity to kill the growing stages of the parasite in mosquito vector. The available antimalarials are highly selective in their action [7, 8] and a combination of drugs is needed to achieve chemoprophylactic and curative action. An ideal antimalarial drug, which has activity against different phases of the malarial parasites, is yet to be developed.

Synthesis of substituted benzamides, benzimidazoles and benzoxazines as potential anthelmintic and antimicrobial agents.

Abstract: A number of substituted benzamides 5–21, 2,5(6)-disubstituted benzimidazoles 12–24, 6-chloro-3-(2-nitro-5R-phenyl)-2,3-benzoxazines 15–28 and 3,8-dichloro-6-oxobenzimidazo[3,2-α] [1,3]benzoxazine (19) have been synthesized. Their anthelmintic and antimicrobial activities are reported. Synthese von substituierten Benzamiden, Benzimidazolen und Benzoxazinen als potentielle Anthelmintika und antimikrobielle Agenzien Eine Reihe von substituierten Benzamiden 5–11, 2,5(6)-disubstituierten Benzimidazolen 12–14, 6-Chlor-3-(2-nitro-5R-phenyl)-1,3-benzoxazinen 15–18 und 3,8-Dichlor-6-oxobenzimidazo[3,2-a][1,3]benzoxazin (19) wurden synthetisiert. Sie wurden auf ihre anthelmintische und antimikrobielle Aktivitat getestet.

Clinical and experimental keratitis due to Curvularia lunata (Wakker) Boedijn var. Aeria (Batista, Lima and Vasconcelos) Ellis

Abstract: A case of mycotic keratitis due to Curvularia lunata var. aeria is reported for the first time from India. Direct microscopic examination of the corneal scrapings in KOH (50gl-1), stained with lactophenol cotton blue, revealed brown septate hyphae and the cultures were found positive for fungus. It was identified as C. lunata (Wakker) Boedijn var. aeria (Batista, Lima and Vasconcelos) Ellis (IMI 253204) and its growth was better at 28°C than at 37°C. In vitro, the fungus was most sensitive to amphotericin B followed by miconazole nitrate, clotrimazole and triphenyltin isoselenocyanate 4-picoline which had the same activity. Lactones were least active and tolciclate and arnebins were inactive. The fungus produced experimental keratomycosis in the rabbit cornea and the infection severity as well as histopathological changes were more pronounced in rabbits that received penicillin, streptomycin and cortisone.

Setaria cervi: enzymes in microfilariae and in vitro action of antifilarials.

Abstract: Microfilariae of bovine filarial parasiteSetaria cervi are equipped with the enzymes of glycolysis, pentose phosphate and PEP-succinate pathways and thus resemble the adult form in its metabolic pattern. Malate dehydrogenase was the most active enzyme in microfilariae followed by lactic dehydrogenase and fumarase, while phosphoglucoisomerase, PEP-carboxykinase and FDP-aldolase were comparatively less active. The very low ratio of PK/PEPCK inS. cervi microfilariae indicates active fixation of CO2 into PEP to produce oxalacetate. Centperazine and diethylcarbamazine significantly inhibited PEP-carboxykinase, fumarate reductase and succinic dehydrogenase, suggesting that these antifilarials probably exert microfilaricidal action by blocking the PEP-succinate pathway.

Symbiotic nitrogen fixation efficiency of mutant strains of lentil (Lens esculenta) Rhizobium growing from pH 4-5 to 7-5

Abstract: A strain of Rhizobium isolated from the root nodule of lentil was caused to produce mutants and screened on a medium of pH 4·5. Five mutant colonies of Rhizobium were isolated from lentil which differed in growth over a pH range 4·5–7·5. Strains differed in their growth in acidic and calcareous soils and also in their effectiveness of N fixation.

The enzyme linked immunosorbent assay in the immunodiagnosis of human malaria

Abstract: The sera of 20 malaria (Plasmodium vivax) positive patients were examined for the presence of antibodies by enzyme linked immunosorbent assay (ELISA) using heterologous P. knowlesi antigen collected from parasitized erythrocytes from a Rhesus monkey (Macaca mulatta). All the samples from malaria patients gave a strong ELISA test. The test was negative or weak with the sera of control subjects.

Zinc in the epididymal and vasal spermatozoa of rhesus monkey (Macaca mulatta).

Abstract: Zinc level in maturing spermatozoa collected from caput, corpus, and cauda regions of the epididymis and vas deferens of rhesus monkey was measured. Spermatozoa collected from the caput epididymis have the highest concentration of zinc (36μg/108 spermatozoa). There was a marked reduction in the zinc content of corpus spermatozoa and a further decrease in the spermatozoa of cauda epididymis. Thus the zinc content of spermatozoa gradually decreases as they migrate from the caput to cauda epididymis. There was a significant increase in the zinc content of vasal spermatozoa as compared to those collected from the cauda region of epididymis.

Enzyme linked immuno-sorbent assay for detection of antibody activity in female genital tract of immunized rabbits.

Abstract: A method to assay anti-HCG activity was developed. Polystyrene micro-ELISA plates were coated with HCG and uterine and tubal washings were incubated in the wells. Sera were diluted to equate the protein content with that in the washings and were included in the assay to serve as internal reference standards. Anti-rabbit-IgG (sheep) conjugated to horse-radish peroxidase was added to each well and enzyme activity was monitored using ortho-phenyl-diamine as chromogen agent. Enzyme activity was a direct measure of anti-HCG activity. This method was used to compare anti-HCG activity in the genital tract fluid of rabbits immunized with HCG with that of serum from the same animal. The results of the present study show that at equal protein concentrations, the anti-HCG activity was only 2.64% to 18.73% of the activity present in serum. Thus, it seems that antibody activity in the genital tract of the female rabbits immunized systemically may not be sufficient enough to neutralize the biological function of the antigen needs for contraceptive protection.

Chemotherapy of hookworm infections.

Abstract: Among the various helminth parasites which infect man, livestock, poultry and pets, the intestinal helminths pose the most serious threat to the health and general well being of the population. The hookworms are one of the important intestinal nematodes whose prevalence and concomitant detrimental effects upon the body functions have made them to be ranked as one of the important helminthic disease problems of man today. The worms stealthily sap the vitality of the patients long before the symptoms appear and the disease is diagnosed. If unattended, the infection may take a devastating socioeconomic and medical toll in the endemic areas.

Increased virulence ofMycobacterium avium Kirschberg in thioacetamide treated rabbits

Abstract: An attempt has been made to determine the correlation between liver damage and the virulence of mildly pathogenicMycobacterium avium in thioacetamide treated rabbits. Liver damage increased the susceptibility of rabbits to infection even with a moderately virulent organism.