PubMed Health⌕ Search

Biomedical subjects

H Mauss

Publications and source records attributed to H Mauss.

16 recordsLinked to original sources
PubMed1986

Identification of fibronectins in peritoneal macrophages during the phagocytosis of Brucella. An immunocytochemical study by electron microscopy.

Fibronectin is a high-molecular-weight molecule whose opsonic properties favor the endocytosis of bacteria and particulate material. Using immunolabeling with anti-fibronectin IgGs coupled with peroxidase, we have looked for its localization in peritoneal macrophages from antigenically stimulated and nonstimulated mice. Ultrastructural location of fibronectin in macrophages sheds light on several points. It confirms that it is synthesized and secreted by mouse peritoneal macrophages. In addition, we found significant variability among the cells of a given population, and also between populations from stimulated and nonstimulated animals. Under certain conditions macrophages secrete an extracellular matrix whose aspect varies with the physiological conditions, but which generally consist of fibronectins either on a fibrillar network connecting the macrophages to one another or in an agglutinating extracellular cement. Endocytosis of Brucella by macrophages is accompanied by secretion of fibronectin inside endocytic vacuoles; this secretion contributes to the formation of an electron-dense material closely surrounding phagocytosed bacteria.

Animals↗
PubMed1975

Peripheral nervous system involvement in experimental tuberculosis.

Following intravenous injection of mycobacteria in the mouse the bacilli are regularly found in the peripheral nervous system after the 5th day. The peripheral nerves and autonomic ganglia are involved at the level of the perineural cells and the sheath of Schwann. When the organisms are of low virulence (BCG, Mycobacterium intracellulare) the development of the nodules is limited. In the case of a virulent strain (Ravenel) extensive granulomas are found but epitheloid cells, always found in other organs, are constantly absent. In animals previously immunized, the bacilli seem to implant themselves as in the controls, but multiply more slowly; the nodules are more infrequent and the lymphoid infiltration appears earlier with the multiplication of interstitial cells.

Animals↗
PubMedDate not supplied

Response of the lymphoid organs of the mouse to the peptidoglycan of a gram-positive bacterium (Streptococcus pyogenes).

The response of the lymphoid organs of the mouse to the injection of a Gram-positive (Streptococcus pyogenes) bacterial peptidoglycan (PGL) has been investigated by several complementary techniques. Special cares were brought to: a) the extraction mode and the characterization of the bacterial fraction, b) the sanitary and microbiological status of the mice, and c) the lack of biologically active contaminants, even at a trace level. In these conditions, the local reaction at the site of inoculation was very moderate, transient and not very distinctive. No toxic reactions were observed, even with doses of several milligrams per mouse. Changes in lymphoid organs, as determined by changes in weight, incorporation of radioactive precursors and detailed histological study revealed that PGL did not induce the typical responses of ordinary antigens. Changes in the weight of organs were not significant and there was no dose-response relationship. In the lymph node, the response was confined to the paracortical area; the lymphocyte activation stood at an early stage and became characterized only after booster injection. There was no activation of antibody-producing cells. An important recruitment of active macrophages was observed; this could participate to the adjuvant activity of PGL, whose at least a part of the biological activity is therefore independent of the inflammatory and/or toxic response.

Animals↗