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1.
Kitasato Arch Exp Med ; 64(4): 205-12, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1823920

RESUMO

Mycobacterium leprae is an obligate intracellular parasite and grows within mononuclear phagocytes. When murine macrophages derived from the peritoneal cavities of CBA mice were infected in vitro with M. leprae (Thai-53 strain), intracellular multiplication was observed three weeks after infection. On the other hand, there was no increase in the number of heat-killed M. leprae at the same times after infection. Morphological studies showed that the growth rate of the bacteria increased by about 20-30% in medium supplemented with cycloheximide. With the addition of cycloheximide to the culture medium, metabolic activity of macrophages was decreased but infected cells were maintained in good condition and seldom floated off from the culture flask.


Assuntos
Técnicas Bacteriológicas , Cicloeximida/farmacologia , Macrófagos/microbiologia , Mycobacterium leprae/crescimento & desenvolvimento , Animais , Divisão Celular/efeitos dos fármacos , Feminino , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos CBA/microbiologia
2.
Kitasato Arch Exp Med ; 64(4): 213-20, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1823921

RESUMO

Mycobacterium leprae is an obligate intracellular parasite which grows within mononuclear phagocytes. In clinical cases, M. leprae reaches enormous numbers in the macrophage-rich granulomas of leprosy. Peritoneal macrophages from CBA mice were cultured in Waymouth medium containing fresh horse serum in Costar 3424 trays (24 wells, 16 mm in diameter) each containing 9 x 12 mm cover slips. This medium was supplemented with 0.5 micrograms/ml of cycloheximide. These cells were infected with M. leprae Thai-53 strain obtained by nude mice inoculation. Significant multiplication of the acid-fast bacilli in the macrophages was observed three weeks after inoculation. This experiment showed M. leprae mainly multiplied in cells and not by rephagocytization of M. leprae derived from destroyed cells.


Assuntos
Técnicas Bacteriológicas , Macrófagos/microbiologia , Mycobacterium leprae/crescimento & desenvolvimento , Animais , Técnicas Bacteriológicas/instrumentação , Divisão Celular/efeitos dos fármacos , Cicloeximida/farmacologia , Feminino , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos CBA/microbiologia , Camundongos Nus/microbiologia , Fagocitose
4.
Infect Immun ; 41(1): 121-7, 1983 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6345387

RESUMO

Macrophage cultures pulsed with viable Mycobacterium leprae were assessed for erythrocyte rosetting in three groups of individuals, i.e., normal subjects, and tuberculoid and lepromatous patients. Of these, only the lepromatous group showed a reduction in rosetting ability after infection with M. leprae. The specificity of such a reduction pattern was confirmed by using various mycobacteria to infect the macrophages. A threshold effect was noted in all three groups. Although a reduction was obtained in the amount of rosetting of macrophages from lepromatous patients with 10(4) acid-fast bacilli per culture, tuberculoid and normal macrophages resisted such an effect with as large a dose as 20 X 10(6) to 30 X 10(6) and 30 X 10(6) bacilli per culture, respectively. The M. leprae-caused alterations in macrophages from lepromatous patients were reversible by treatment with trypsin and colchicine. Cytochalasin B and Tween 80 were unable to alter the pattern. Treatment of cells with neuraminidase was inconclusive since it enhanced rosetting values of both control and infected cultures. These manipulations were significant in elucidating the target point of the host (macrophage) and parasite (M. leprae) interaction and in delineation of the external and internal effects upon the macrophages. Both M. leprae and macrophages were participants in Fc reduction, as treatment of the former with rifampicin and of the latter with cyclocheximide significantly augmented the rosetting ability. In conclusion, it appears that M. leprae, upon entering a lepromatous macrophage, initiates the production of a protein which acts via the microtubules to alter membrane topography. It is possible that the altered membrane prevents effective macrophage-lymphocyte interaction. This could be one of the mechanisms by which cell-mediated immunity is suppressed in lepromatous leprosy.


Assuntos
Hanseníase/imunologia , Macrófagos/imunologia , Mycobacterium leprae/fisiologia , Animais , Células Cultivadas , Colchicina/farmacologia , Cicloeximida/farmacologia , Citocalasina B/farmacologia , Humanos , Macrófagos/microbiologia , Neuraminidase/farmacologia , Polissorbatos/farmacologia , Receptores Fc/fisiologia , Rifampina/farmacologia , Formação de Roseta , Tripsina/farmacologia
5.
Int J Lepr Other Mycobact Dis ; 51(1): 72-6, 1983 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6345414

RESUMO

A serial increase in the number of Mycobacterium lepraemurium with successful subcultures has been obtained in cell culture with cycloheximide treatment. The infected cells seldom floated off the culture vessel. They could be maintained and would support the bacillary multiplication in good condition for ten weeks or more without changing the medium frequently. An overall generation time of the intracellular bacilli up to the tertiary culture for the total period of 35 weeks was 22.1 days.


Assuntos
Cicloeximida/farmacologia , Mycobacterium lepraemurium/crescimento & desenvolvimento , Células Cultivadas , Meios de Cultura , Mycobacterium lepraemurium/efeitos dos fármacos
6.
J Gen Microbiol ; 128(2): 423-5, 1982 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7042905

RESUMO

Mycobacterium leprae isolated from armadillo tissue incorporated radioactivity from D-(14C)glucose and (14C)protein hydrolysate. In the presence of glucose, the rate of incorporation of (14C)protein hydrolysate was increased. Uptake of glucose was inhibited by 2-deoxy-D-glucose and sodium azide; that of the amino acids was inhibited by puromycin and chloramphenicol and, weakly, by cycloheximide.


Assuntos
Aminoácidos/metabolismo , Glucose/metabolismo , Mycobacterium leprae/metabolismo , Azidas/farmacologia , Proteínas de Bactérias/biossíntese , Transporte Biológico , Cloranfenicol/farmacologia , Cicloeximida/farmacologia , Cinética , Puromicina/farmacologia , Azida Sódica
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