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M M Monteiro

Publications and source records attributed to M M Monteiro.

3 recordsLinked to original sources
PubMed2000

Distinct ability to accumulate eosinophils during the inflammatory cellular response to M. bovis BCG in the mouse pleural cavity.

OBJECTIVE AND DESIGN: The host response to Mycobacteria focuses on the development of cell-mediated immunity and granuloma formation. Here, we investigated the onset of cellular responses to mycobacteria in murine pleurisy. MATERIAL: Distinct mouse strains previously described as Bcg susceptible or resistant were inoculated intrathoracically with different doses of live M. bovis BCG. METHODS: At various time intervals, cells harvested from the inflammatory site were identified and ultra-structurally analysed. RESULTS: BCG-induced pleurisy had two peaks of cellular influx at 1 and 15 days after infection. At the first half hour, macrophages were found to be heavily infected. Neutrophil arrival started after 2 h of infection and peaked at 4 h. At this time, neutrophils were found ingesting mycobacteria exclusively with a high infecting dose. BCG was potently more eosinophilotactic in Bcg susceptible mice than in the resistant ones and to other well known eosinophilia inducers: IL-5, PAF-acether or LPS. CONCLUSIONS: Mycobacterial load and mouse susceptibility seem to determine the early granulocyte dynamics in the lesion.

Adjuvants, Immunologic↗
PubMed1999

Structural elements common to mitosis and apoptosis.

Both mitotic and apoptotic cells display hypercondensation of the chromatin and loss of the nuclear envelope (Lazebnik et al., 1993). Herein, we describe a third similarity between the two processes. We have observed, initially in apoptotic cells of the PC-12 lineage clusters of 40-60 (approximately 50) nm vesicles adjoined by a minor contingent of tubule vesicular elements of 100-200 nm which are indistinguishable from their vesicular counterparts in mitotic PC-12 cells. The clusters of approximately 50 nm vesicles were subsequently observed in all studied rat tissue cells in apoptosis (plasma cells and macrophages, secretory epithelial cells from pancreatic acini, ventral lobe of prostate and mammary gland). Clusters of approximately 50 nm vesicles comparable to those of the PC-12 cells were found in HeLa cells treated with human alfa TNF, in WEHI-3 cells exposed to VM 26 (a teneposide) (Sesso et al., 1997) and in HL-60 cells treated with thapsigargin. PC-12 and HeLa cells affixed to coverslips were double labelled and examined with the fluorescence microscope to reveal simultaneously the disposition of the chromatin with Hoechst stain and the distribution of the fluorescence of Golgi or of Golgi-associated proteins. A common pattern of fluorescence was observed in a minor proportion of apoptotic cells using three different antibodies used. The label frequently appeared as finely dispersed granules in the cytoplasm. In some apoptotic cells, relatively coarse granules were observed. This pattern of label distribution is compatible with the disposition of vesicular clusters we have encountered in apoptotic PC-12 cells sectioned serially or semi serially. In such sections of both mitotic and apoptotic PC-12 cells, we noticed that the conglomerates of 50 nm vesicles were frequently associated with cisternae of the rough ER. Vesicles of similar size were also noted pinching off from the extremities of Golgi cisternae reduced in size. These cisternae diminish in length and width when they are in the process of disassembling at the very beginning of mitosis and in apoptosis.

Animals↗