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Biomedical subjects

C L Fischer

Publications and source records attributed to C L Fischer.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Skylab experiment results: hematology studies.

These studies were designed and coordinated to evaluate specific aspects of man's immunologic and hematologic systems which might be altered by or respond to the space flight environment. The biochemical functions investigated included cytogenetic damage to blood cells, immune resistance to disease, regulation of plasma and red cell volumes, metabolic processes of the red blood cell, and physical chemical aspects of red blood cell functions. Only minor changes were observed in the functional capacity of erythrocytes as determined by measuring the concentrations of selected intracellular enzymes and metabolites. Tests of red cell osmotic regulation indicated some elevation in the activity of the metabolic dependent Na-K pump, with no significant alterations in the cellular Na and K concentrations or osmotic fragility. A transient shift in red cell specific-gravity profile was observed on recovery, possibly related to changes in cellular water content. Measurements of hemoconcentration (hematocrit, hemoglobin concentration, red cell count) indicated significant fluctuations postflight, reflecting observed changes in red cell mass and plasma volume. There was no apparent reticulocytosis during the 18 days following the first manned Skylab mission in spite of a significant loss in red cell mass. However, the reticulocyte count and index did increase significantly 5 to 7 days after completion of the second, longer duration, flight. There were no significant changes in either the while blood cell count or differential. However, the capacity of lymphocytes to respond to an in vitro mitogenic challenge was repressed postflight, and appeared to be related to mission duration. The cause of this repression is unknown at this time. Only minor differences were observed in plasma protein patterns. In the second mission there were changes in the proteins involved in the coagulation process which suggested a hypercoagulative condition.

Aerospace Medicine↗
PubMedDate not supplied

Lymphocyte blastoid transformation assay by cytofluorography.

This rapid, automated, micromethod quantitates blastoid transformation using a supra vital stain, acridine orange, in quantitating the ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) before and after cell stimulation. Only 0.2 ml of culture containing 1.0 X 10(5) to 1.5 X 10(5) lymphocytes is required to obtain results every 5 minutes. These results include a total cell count and cell counts of the populations with increased RNA (I-RNA), and increased DNA (I-DNA). The I-RNA and I-DNA lymphocyte populations, as determined by the cytofluorometric method, correlate well with the accepted H3 uridine and C14 thymidine uptake methodology. The phytohemagglutinin dose response measurements by the 2 methods also correlate well. Blast cell counts, by Wright-Giemsa staining, showed near identity to the I-RNA cell population.

Blood Cell Count↗
PubMedDate not supplied

Automated differential cell counting of viable cells.

A rapid, automated method of differentially counting viable cells by ethidium bromide-acridine orange cytofluorography is described (Takasugi 1971). The method is shown to have comparability, equal precision, and sensitivity to the standard trypan blue, visual method. The method is applicable to microcytotoxicity testing.

Automation↗