title: Human cellular immune responsiveness following space flight.
abstract: Peripheral circulating lymphocytes were separated from astronaut blood samples three times before and two times after the first four US Space Shuttle flights. The ability of the in vitro T lymphocytes to respond to Phytohemagglutinin by blastogenesis was found to be reduced for each crewmember following spaceflight. In addition, the astronauts experienced a postflight increase in neutrophils and a decrease in eosinophils. These postflight changes in leukocytes are shown to increase with subjectively-evaluated increases in the incidence of inflight stress, indicating that stress, and not hypogravity, is likely to be the major effector of these changes.
mesh_terms: D000337:Aerospace Medicine; D004804:Eosinophils / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D010835:Phytohemagglutinins; D013026:Space Flight; D013312:Stress, Physiological / Q000276:immunology; D014481:United States
chemical_list: D010835:Phytohemagglutinins