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Biomedical subjects

M Bessis

Publications and source records attributed to M Bessis.

At least 55 records · Page 3Linked to original sources
PubMed1970

Cell death.

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Cell Biology↗
PubMed1966

An electron microscopy study of vitally stained single cells irradiated with a ruby laser microbeam.

An electron microscope study has been made of vitally stained single cells whose cytoplasm has been subjected to a localized ruby laser microbeam. Light and moderate laser absorption (the resultant of stain concentration and laser energy density) produced restricted selective damage of mitochondria in cells stained with Janus green B; heavy laser absorption resulted in mitochondrial damage, as well as in nonselective interaction with other cell structures. With four other basic vital stains, the polysomes, ergastoplasm, mitochondria and other organelles at the irradiated site were uniformly damaged. Unstained cells showed no morphological alterations. With light primary damage (that restricted to the irradiation site), no secondary effects of the incident radiation were observed. With moderate primary damage, however, secondary damage of the mitochondria in the unirradiated cell portions was produced, which was reversible within 4 hr after irradiation. Heavy primary lesions caused severe secondary alteration of all cell structures that was irreversible and cell death occurred within 2 hr. Surviving cells examined 24 hr after light and moderate irradiation could not be distinguished from unirradiated controls. The possible mechanisms involved in the production of laser-induced cellular alterations are discussed.

Animals↗
PubMedDate not supplied

Origin of stress macroreticulocytes from macronormoblasts.

Stress erythropoiesis was induced in rats and guinea-pigs by graded amounts of bleeding and phenyl-hydrazine administration. Hemoglobin and DNA content was measured by microspectrophometry of single erythroblasts in the process of nuclear extrusion. DNA content was always 2 C. Hemoglobin content was in all cases superior to the normal value, occasionally reaching a value of almost twice normal.

Animals↗