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Biomedical subjects

B Gay

Publications and source records attributed to B Gay.

At least 73 records · Page 4Linked 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↗
PubMed1984

Ultrastructural localization of NADPH-oxidase activity in murine peritoneal macrophages during phagocytosis of Brucella. Correlation with the production of superoxide anions.

The localization of the enzyme NADPH oxidase in mouse peritoneal macrophages unstimulated or after phagocytosis of Brucella suis was investigated by electron microscopy in normal mice and mice immunized against B. suis. The enzyme was clearly visualized on mitochondrial cristae, smooth endoplasmic reticulum, and the plasma membrane; its activity correlated mainly with the state of the endoplasmic reticulum which itself reflected macrophage activation. The enzyme turnover appeared to be accelerated after phagocytosis; the phagosome membrane was seldom stained by the enzyme reaction. These macrophages were also examined for the production of superoxide anions in vitro, either unstimulated or after phagocytosis. Phagocytosis increased the production of superoxide anions, especially in immunized animals. These results are discussed with regard to the role that the products of oxidative metabolism play in the inactivation of bacteria by phagocytic cells.

Animals↗
PubMed1983

[Experiences in the after treatment of surgically treated ligament rupture of the ankle joint using a special shoe].

Early surgical reconstruction of lesions of ankle joint ligaments is generally accepted and yields best functional results. The wearing of a cast for 6-7 weeks limits movement to a greater extent than required for ligament healing. Functional physiotherapy and the use of a special shoe results in healing equal to that obtained with casts, but without the disadvantages of prolonged wearing of a cast. The high laced, laterally reinforced shoe permits physiotherapy and limited movement. The disadvantages of complete immobilization and trophic changes are avoided, while the ligament can be mobilized without undue strain. Extreme movements such as supination, adduction and maximal extension and flexion are prevented as effectively as with a cast. The time during which the patient is unable to work is reduced for most vocations, which also reduces insurance costs. This postoperative physiotherapy of a selected, active patient group is an effective alternative to conventional cast immobilization.

Adolescent↗