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Duane L. Pierson, Ph.D. NASA Johnson Space Center Houston, Texas. ADAPTATION TO SPACEFLIGHT. Neurosensory adaptations. Psychological-Behavioral- Performance issues. Taste and odor sensitivity. Cardiovascular adaptations. Sleep and circadian rhythm disturbances.
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Duane L. Pierson, Ph.D. NASA Johnson Space Center Houston, Texas
ADAPTATION TO SPACEFLIGHT Neurosensory adaptations Psychological-Behavioral- Performance issues Taste and odor sensitivity Cardiovascular adaptations Sleep and circadian rhythm disturbances Gastrointestinal alterations Fluid shifts, hematological changes Bone loss Muscle loss Immune changes
HUMAN IMMUNE RESPONSE • Blood Cell Count • Lymphocyte Proliferative Responses • Cell Mediated Immunity • Cytokine Production • NK Cell Cytotoxicity • Humoral Factors • Specific Antibody Response • Wound Healing • Neutrophil Functions
FACTORS INCREASING DISEASE RISK HEALTH HEALTH DISEASE DISEASE • Crowded Living Conditions • • Closed-Loop Environment (Water/Air) • • Reduced Capability for Personal Hygiene • • Limited Clean-up and Disinfection Capability • • Inability to Isolate Contagious Crewmember • • Limited Treatment Capability and Crew Return • • Altered Immune Response •
INFECTIOUS DISEASE RISKS Skin Infections • Gastrointestinal Distress • Urinary Tract Infections • Upper Respiratory • Latent Viral Reactivation •
WHY HERPESVIRUSES? • Herpesviruses are the most readily recognized latent viruses. • These viruses are ubiquitous and represent important infectious disease risks with oncogenic potential. • They are not mitigated by preflight quarantine. • Space flight stress alters immune response. • Diminished immunity results in reactivation and dissemination (“shedding”) of latent viruses. SPECIFIC APPLICATION May be used as an early predictor of impending medically significant changes in the immune response.
Antarctica: EBV 5 Post Pre Isolation Subject 1 Normal 4 3 DTH response EBV DNA O.D. @ 405nm Hypoergic 2 Anergic 1 0 -100 -50 0 50 100 150 200 250 Days in Isolation
EBV Frequency:16% EBV copies 417+ 31 2-4 5-7 8-14 Day of flight Space Shuttle: EBV copies 1000 • Control • Mir n = 32 Space Flights = 10 800 600 EBV Copies per ml 400 EBV Frequency: 29% EBV copies 40+ 2 EBV Frequency: 16% EBV copies 44+ 5 200 0 200-140 139-60 59-1 1-30 31-45 Day after recovery (R+) Day before launch (L-)
Space Shuttle: CMV Frequency 30 n = 71 25 20 % Positive CMV Urine Samples 15 10 5 n = 61 0 Astronauts Control
† 15 CMV Shedders * * * * significant increase from BL (p<0.001) † significant increase from L-10 (p< 0.001) CMV IgG Antibody Titers 8 55 Astronauts 40 non-shedders 7 6 CMV IgG Antibody Titers (Mean +/- SE log2) 5 4 3 2 BL L-10 R+0 R+3
CONCLUSIONS Space flight is a unique stress model Antarctic Science Stations model many aspects of space flight Stress associated with space flight results in increased reactivation of EBV, CMV and VZV. Viral reactivation in astronauts appears to be linked to duration in Space (Stress/ Microgravity ?). Space flight associated stress manifested through the HPA-axis result in increased stress hormones, reduced CMI, and increased viral reactivation.
ACKNOWLEDGEMENTS • Satish K Mehta, Ph.D., NASA-JSC • Desmond J. Lugg, M.D., Australian Antarctic Div, Hobart, Australia • Janet S. Butel, Ph.D., NSBRI/Baylor College of Medicine, Houston,TX • Randall J. Cohrs, Ph.D., Uni Colorado Health Sciences Center, Denver Co • Bagher Forghani, Ph.D.,California Department of Health Services, Richmond, CA • Stephen K. Tyring, M.D., Ph.D., UTMB, Galveston, TX • Ronald Glaser, Ph.D., The Ohio State University, Columbus, OH