Fitness, blood, and urine measurements from the 2009 European astronaut selection medical examination.

INTRODUCTION: The European Space Agency conducted an astronaut selection campaign in 2008-09 which attracted over 8000 applicants. Of those, 45 made the final assessment stage: the medical examination (MEX). This retrospective, observational study reports exercise and fitness data, lipid profiles and other results of interest from the blood and urine samples of this niche subpopulation. METHODS: All the applicants that reached the MEX completed a Bruce protocol test and a standard blood draw (12 h of fasting, water intake was ad libitum) was collected together with a 24-h urine collection. All the results were compared to either a comparative population or reference range. RESULTS: The applicants had comparable fitness levels to the 90th percentile of their age group. The lipid profiles were observed to be within the 'optimal' or 'desirable' ranges. Bilirubin and creatinine clearance were measured at 1.2 (+/- 0.40) mg x dl(-1) and 131.0 (+/- 25.81) ml x min(-1), respectively, and both were shown to be significantly higher than their respective normative ranges, while urinary creatinine (0.65 (+/- 0.19) g x L(-1)) was significantly lower than the reference range. DISCUSSION: Overall, the results from the Bruce protocol and lipid profile show that the final round applicants were in good health and physically active. The most likely cause of the elevated bilirubin and creatinine levels was 'last-minute' exercise conducted by the final round applicants before the MEX and the low levels of urinary creatinine may be attributed to drinking high quantities of water with an associated hypovolemia, diluting the urine.

Effects of Venoconstrictive Thigh Cuffs on Dry Immersion-Induced Ophthalmological Changes.

Neuro-ophthalmological changes named spaceflight associated neuro-ocular syndrome (SANS) reported after spaceflights are important medical issues. Dry immersion (DI), an analog to microgravity, rapidly induces a centralization of body fluids, immobilization, and hypokinesia similar to that observed during spaceflight. The main objectives of the present study were 2-fold: (1) to assess the neuro-ophthalmological impact during 5 days of DI and (2) to determine the effects of venoconstrictive thigh cuffs (VTC), used as a countermeasure to limit headward fluid shift, on DI-induced ophthalmological adaptations. Eighteen healthy male subjects underwent 5 days of DI with or without VTC countermeasures. The subjects were randomly assigned into two groups of 9: a control and cuffs group. Retinal and optic nerve thickness were assessed with spectral-domain optical coherence tomography (OCT). Optic nerve sheath diameter (ONSD) was measured by ocular ultrasonography and used to assess indirect changes in intracranial pressure (ICP). Intraocular pressure (IOP) was assessed by applanation tonometry. A higher thickness of the retinal nerve fiber layer (RNFL) in the temporal quadrant was observed after DI. ONSD increased significantly during DI and remained higher during the recovery phase. IOP did not significantly change during and after DI. VTC tended to limit the ONSD enlargement but not the higher thickness of an RNFL induced by DI. These findings suggest that 5 days of DI induced significant ophthalmological changes. VTC were found to dampen the ONSD enlargement induced by DI.

[Innovation in healthcare in space to improve life on Earth]. / L'innovation en santé dans l'espace pour améliorer la vie sur Terre.

Today, sending people into space has become almost routine. However, it is a potentially dangerous environment for humans. Astronauts' health is closely monitored to ensure they are fit to continue their mission. The conquest of space has also resulted in the development of numerous tools and medicines beneficial for all living beings on Earth.

Optimization of an elispot assay to detect cytomegalovirus-specific CD8+ T lymphocytes.

Various arguments suggest that CD8+ T lymphocytes play a major role in the control of cytomegalovirus (CMV) infection. The detection of CMV-specific CD8+ T cells may therefore provide additional information about CMV virus detection to predict the risk of development of CMV disease, especially in immunodepressed transplant recipients. We compared and tested various experimental conditions to optimize an enzyme-linked immunospot assay (Elispot) assay for the detection of CMV-specific CD8+ T lymphocytes. The indirect Elispot assay with one six-day in vitro sensitization step was found to be the most sensitive method to detect CMV-specific CD8+ T cells compared to direct Elispot with unfractionated peripheral blood mononuclear cells or purified CD8+ T cells. We showed that low doses of interleukin-2 during the in vitro culture enhanced the sensitivity of this test, and tetramer staining was performed to verify the high efficiency of this in vitro stimulation step. We directly loaded the specific CMV peptide during the Elispot assay and demonstrated that the use of T2 cells did not improve its sensitivity. Elispot for the detection of interferon-gamma appears to be more sensitive and reliable than measurement of tumor necrosis factor alpha or granzyme B. This technique was successfully applied to detect CMV-specific CD8+ T cells in human leukocyte antigen A2 (HLA-A2) and HLA-B7 healthy patients and in one lymphopenic post-transplant patient with positive CMV serology. This highly sensitive test may be a useful tool to assess T-cell immunity directed against CMV in immunodepressed patients.

[Cytotoxic T lymphocytes: role in immunosurveillance and in immunotherapy]. / Les lymphocytes T-CD8: rôle dans l'immunosurveillance et l'immunothérapie antitumorale.

Experiments in mice and recent human clinical studies have clearly shown the contribution of CD8+ T lymphocyte in the control of tumor development. CD8+ T lymphocytes are a constitutive component of the immune response during the development of cancer. In murine models, the efficiency of various cancer vaccines mainly depends on their ability to induce CD8+ T lymphocytes. Clinical responses in immunotherapy treated cancer patients have been associated with the presence of antitumor specific CD8+ T lymphocytes. In spontaneous regressive melanomas, intratumor antigen specific CD8+ cytotoxic T cells were expanded suggesting their involvement in the tumor shrinkage. Administration of antitumor specific cytotoxic T clones in mice resulted in antitumor responses which directly demonstrated the therapeutic efficiency of these cells. However, in most cases during cancer progression, the presence of antitumor CD8 T lymphocyte is not associated with clinical responses. Intrinsic functional abnormalities of these cells or a defect of CD8+ T cell migration to the tumor may in part explain their failure to inhibit tumor development. On the other hand, tumors also develop immune escape mechanisms (down modulation of tumor antigens, secretion of immunosuppressive factors, expression of anti-apoptotic molecules by the tumors, or pro-apoptotic factors inducing T cell death) to resist to the CD8+ T cell attack. To circumvent these tumor escape mechanisms, efficient cancer vaccines will have to recruit CD8+ T cells associated with other immune effectors.