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Biomedical subjects

B R Chatterjee

Publications and source records attributed to B R Chatterjee.

29 records · Page 2Linked to original sources
PubMed1976

Acid-fast bacillary positivity in asymptomatic individuals in leprosy endemic villages around Jhalda in West Bengal.

Three general surveys of a village population of 7000 in a highly endemic area in Purulia District, West Bengal, have included clinical examination and earlobe skin snip examinations. Multiple between-survey follow-up examinations have also been conducted of both bacillary positives and cases. In the general population 5.8% of the individuals showed bacteriological positivity with a concentration technique for AFB without showing clinical signs of infection. During two years of observation clinical leprosy was diagnosed in 13.6% of bacillary positives, in 4.8% of nuclear family contacts of clinical cases and 2.3% of the rest of the general population of the villages.

Adolescent↗
PubMed1976

A non-acid-fast coccoid precursor--possible cultivable phase of Mycobacterium leprae.

A non-acid-fast coccoid organism isolated from human leproma, and skin and nasal smears of leprosy patients shows tendency to revert to an acid-fast mycobacterial form during test tube passages. One of these coccoid isolates gave strong DOPA oxidase activity. There is also preliminary evidence of mycobacterial conversion from these coccoids in intraperitoneally inoculated mice. The possibility that these non-acid-fast coccoids could be a cultivable precursor phase of M. leprae has been raised and discussed.

Animals↗
PubMedDate not supplied

Leprosy immunopathogenesis and vaccine development.

The truly effective immunity against intracellular parasites, including mycobacteria, is mediated by monocyte/macrophages, and in the immunologically responding (resistant) host these phagocytes need minimal antigenic stimulus, specific or non-specific, to become activated and be microbicidal. T-cell mediated delayed hypersensitivity (DTH) causes tissue damage and destruction, which is particularly unwelcome in leprosy because of its nerve-damaging potential. Gamma interferon (INF-gamma), the terminal lymphokine of a DTH response, promotes mycobacterial survival and growth. There are T-cells (TH1 subtypes) that produce DH response either independent of, or, only partly dependent on INF-gamma; this type of DH peaking at 24 hours appears similar to the Jones-Mote type rather than to the tuberculin type of DTH peaking at 48-72 hours and is devoid of the necrotic component of tuberculin type of DTH. M. leprae antigens normally elicit this Jones-Mote type of DH. Suppressor T-cells are associated with a protective immune response, while helper T-cells mediating DTH are harmful. In view of this immunobiology, it would appear that pathogenic mycobacteria that generate a tuberculin type DTH response should not be used as immunogens in leprosy.

Bacterial Vaccines↗
PubMedDate not supplied

Growth of Mycobacterium leprae in a redox system: II. Further improvements in the system and growth efficiency.

Improvement of the Redox System for growth of M. leprae as brought about by modification in the concentration and mode of preparation of individual media constituents, and by addition of newer substances, is being reported. A structural modification in the construction of the Thunberg's tubes and flasks that are used as culture vessels, has been introduced for ease of handling. Vitamin E (alpha-tocopherol) has been found to be useful. Concentrations of Liposomes and Gelatin in the medium could be reduced by at least five folds, considerably easing thereby smearing and harvesting of cultures. Dimercaptopropanol British Anti-lewisite or BAL) has been used, but its usefulness or otherwise is yet to be determined conclusively. The basis of intracellular parasitism of M. leprae has been discussed.

Adenosine Triphosphate↗