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J Nandi

Publications and source records attributed to J Nandi.

71 records · Page 4Linked to original sources

Evaluation of mycobacillin and versicolin as agricultural fungicides. III. Growth pattern and antibiotic production in soil by Aspergillus versicolor.

Soil supports the growth of a jute pathogen Colletotrichum gloeosporioides but only to a limited extent that of its antagonist Aspergillus versicolor. The growth of the sensitive pathogen is considerably checked by the antagonist in mixed soil culture although versicolin production could not be demonstrated within the limits of assay. Both the sensitive and the antagonistic organisms grow well in soil-compost medium and versicolin production by the latter is also enhanced. The antagonistic effect of Aspergillus versicolor on Colletotrichum gloeosporioides is expectedly more marked in soil-compost medium than in soil medium.

Antifungal Agents↗

Evaluation of mycobacillin and versicolin as agricultural fungicides. II. Stability in soil.

The effect of paddy soils on mycobacillin and versicolin was investigated. Soil inactivated mycobacillin as determined by spectral analysis and microbiological assay. Soil can inactive mycobacillin only at or above the threshold concentration (125 approximately 130 mug per 10 mg of soil), the excess being unreacted. No new peak appears in the ultraviolet spectrum (240 approximately 300 nm) while mycobacillin is inactivated. Soil is without any effect on versicolin.

Adsorption↗

In vitro and in vivo evaluation of versicolin, an antifungal antibiotic.

Versicolin is mainly active against Trichophyton rubrum. It is inactivated by serum. However, attainable blood level can be fifteen to twenty times higher than the fungicidal concentration for as long as 4 hours after a single intravenous administration of the maximum tolerable dose of 25 mg/kg body weight of mouse. It has no haemolytic activity like other polypeptide antibiotics. Skin does not show the presence of any measurable amount of the antibiotic. It is excreted through urine to the extent of 65% of the maximum tolerable dose of the antibiotic administered intravenously. Versicolin is effective against experimental infection by T. rubrum in guinea pigs at dose as low as 2.5 mg/kg body weight. The antibiotic shows no sign of subacute toxicity at these curative doses.

Animals↗

Evaluation of mycobacillin and versicolin as agricultural fungicides. I. Antifungal spectrum and phytotoxicity.

Two antifungal antibiotics, mycobacillin and versicolin, were studied as agricultural fungicides in the control of fungal infection of rice and jute. Mycobacillin is especially active against Piricularia oryzae at a concentration of 10 mug/ml, and versicolin against Colletotrichum gloeosporioides at a concentration of 2.5 mug/ml. Mycobacillin has no adverse effect on germination of seeds and growth of seedlings of rice and jute plants as a concentration of 500ppm, even for prolonged exposure. (24 or 48 hours); in fact, it is stimulatory. On the other hand, versicolin has showed detectable phytotoxicity at 500ppm for prolonged exposure

Antifungal Agents↗

Detection of human immunodeficiency virus antibody among homosexual men from Bombay.

BACKGROUND AND OBJECTIVES: In India, heterosexual transmission of HIV-infection is considered to be the major mode of transmission. However, no report is available on transmission of HIV-infection among homosexually active men. The prevalence of human immunodeficiency virus-1 (HIV-1) and human immunodeficiency virus-2 (HIV-2) infections among homosexual men from Bombay is discussed. GOAL OF THE STUDY: To determine the extent of presence of anti-HIV-1, anti-HIV-2 antibodies, or both anti-HIV-1 and anti-HIV-2 antibodies among homosexual men in India. STUDY DESIGN: Sixty-three blood samples were collected from two STD clinics of Bombay over a 6-month period from men with a history of homosexual behavior who were asymptomatic for HIV-infection. The mean age of the subjects was 31.6 years. For serological detection anti-HIV-1 antibody ELISA was used as the primary screening test followed by Western blot to confirm the results. For distinction between anti-HIV-1 and anti-HIV-2 antibody, line immunoassay was used. The sexually transmitted diseases (STDs) were diagnosed clinically, although Venereal Disease Research Laboratory (VDRL) tests were carried out as a routine test for screening STDs. For detection of gonorrhea, Gram stains of urethral smear were done routinely. RESULTS: From the 63 blood samples tested, 10 samples were reactive by ELISA for HIV-1 infection, and three samples were borderline reactive. These three samples were found to be reactive for anti-HIV-2 by the line immunoassay. The above 10 samples were also positive by Western blot for anti-HIV-1 antibody. Two blood samples were positive for both anti-HIV-1 and anti-HIV-2 antibodies. Using clinical diagnosis as the criteria, the different types of STD among the 63 subjects were as follows: condylomata (22), herpes (20), gonorrhea (15), candidiasis (3), and syphilis (3). However with VDRL, seven subjects were found to be reactive. Gram stains indicated gonorrhea in all the 15 subjects. CONCLUSIONS: This study reports for the first time the homosexual transmission of both HIV-1 and HIV-2 infections in India, although heterosexual transmission still is the major mode of transmission of the infection. The associated incidence of STDs among these men and that a few of these subjects were bisexual make them at high risk for transmission of HIV infection.

Adult↗

Detection of hepatitis B virus DNA in donor blood by the polymerase chain reaction.

BACKGROUND: Blood collected from voluntary donors at local blood banks and blood donation camps was screened for the hepatitis B virus genome using the polymerase chain reaction and for viral markers by standard serological techniques. The sensitivities of the two screening strategies were compared. METHODS: One hundred and twenty-six blood samples were tested for HBV serological markers--HBsAg, anti-Hbs and anti-HBc--by ELISA: The same samples were also subjected to the polymerase chain reaction using primers made by us. RESULTS: Analysis of the polymerase chain reaction amplified products revealed that 24% of the blood samples which tested negative for HBsAg using the ELISA technique were positive for HBV DNA by the polymerase chain reaction. All the HBsAg positive samples (by ELISA) were also positive by the polymerase chain reaction (which detected additional samples as well). Anti-HBc antibodies showed a much greater concordance with the polymerase chain reaction. CONCLUSIONS: The results emphasize that the screening strategies for donor blood need to be re-evaluated in order to check inadvertent transmission of hepatitis B virus during blood transfusion. The ELISA technique to detect HBsAg as the sole serological marker is inadequate to indicate the actual prevalence of hepatitis B virus in the donor blood. The polymerase chain reaction may be a better screening test. If this is not available, the detection of anti-HBc antibodies appear to be a better means of screening blood than HBsAg.

Base Sequence↗

Human immunodeficiency virus-1 infection in spouses of seropositive individuals.

BACKGROUND: Unprotected sex can lead to transmission of the human immunodeficiency virus-1 (HIV-1) to the spouse of an infected individual. We studied the incidence of HIV-1 infection in the spouses of cases diagnosed to have HIV-1 infection by serology and the polymerase chain reaction (PCR). METHODS: Blood samples collected from 9 index cases and their respective spouses were tested for HIV-1 infection by ELISA, Western blot (WB) and PCR as well as from 10 healthy individuals with no high-risk behaviour. DNA extracted from both plasma and peripheral blood mononuclear cells was amplified by PCR, using multiple primer pairs for distinct regions of the HIV-1 genome. Specificity of the PCR product was demonstrated by hybridization to an oligonucleotide probe. RESULTS: All the index cases which were seropositive by ELISA and WB were also positive by PCR of plasma extracted DNA. Eight of the spouses were seronegative. Of these seven were positive by PCR--one spouse was negative by ELISA but showed a p55 band on WB and was positive by PCR. One spouse was negative by serology and PCR. The spouse belonging to the lone concordant couple was positive by serology and PCR. Except for one index case, PCR signals were obtainable only from DNA extracted from plasma but not from the DNA extracted from peripheral blood mononuclear cells. The control samples were negative by serology and PCR. CONCLUSION: It is possible to detect HIV-1 infection by PCR using DNA extracted from plasma even when the individuals are negative by ELISA and WB. It can help in the early counselling of HIV infected persons and their spouses.

AIDS Serodiagnosis↗