Special Operations and Space Medicine for a Joint Future.

This paper is designed to introduce, propose, inform, and advocate enhanced relationships between the medical communities of special operations and space. Although each provides service support in different roles and functions, similarities in both the operational context and in medical care are notable. During a recent interaction, significant relationship potential was discovered by both communities, and recommendations for greater engagement are proposed herein. By identifying and appreciating similarities and understanding history, key actors, and authorities to analyze and realize opportunities will enable us to find synergy for the development of like efforts and goals. Collaboration in research on the limits of human performance and medical support to the most austere and challenging operational environments may benefit both communities in different but productive ways. Establishing and increasing cooperation will also meet command strategic intent, explore and advance a policy concept, initiate a relationship between unique medical communities, and provide a tangible success for the advancement of operational support.

Nourishing the brain on deep space missions: nutritional psychiatry in promoting resilience.

The grueling psychological demands of a journey into deep space coupled with ever-increasing distances away from home pose a unique problem: how can we best take advantage of the benefits of fresh foods in a place that has none? Here, we consider the biggest challenges associated with our current spaceflight food system, highlight the importance of supporting optimal brain health on missions into deep space, and discuss evidence about food components that impact brain health. We propose a future food system that leverages the gut microbiota that can be individually tailored to best support the brain and mental health of crews on deep space long-duration missions. Working toward this goal, we will also be making investments in sustainable means to nourish the crew that remains here on spaceship Earth.

Processes for Designing Innovative Biomedical Hardware to Use in Space and on Earth.

The new era of space exploration is increasing the astronaut's number and diversity in low orbit and beyond. The influx of such a diverse crew population will also increase the need for medical technologies to ensure safe and productive missions. Such a need represents a unique opportunity to innovate and develop diagnostics and treatment tools to meet future needs. Historically, terrestrial regulatory oversight of biomedical design processes was considered separate from spaceflight regulatory processes because it did not address spaceflight constraints. These constraints challenge the creative development of unique solutions for use in space. Translation between healthcare innovation in spaceflight to healthcare on Earth and vice versa requires understanding the commonalities, unique needs and constraints. This manuscript provides a framework for comparing Earth-space design processes and a perspective on the best practices to improve healthcare equity and health outcomes.

Visual stability of laser vision correction in an astronaut on a Soyuz mission to the International Space Station.

UNLABELLED: This report documents the effects of photorefractive keratectomy (PRK) in an astronaut during a 12-day Russian Soyuz mission to the International Space Station in 2008. Changing environmental conditions of launch, microgravity exposure, and reentry create an extremely dynamic ocular environment. Although many normal eyes have repeatedly been subject to such stresses, the effect on an eye with a relatively thin cornea as a result of PRK has not been reported. This report suggests that PRK is a safe, effective, and well-tolerated procedure in astronauts during space flight. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Neuropilin-1 is essential for enhanced VEGF(165)-mediated vasodilatation in collateral-dependent coronary arterioles of exercise-trained pigs.

BACKGROUND/AIMS: Exercise training enhances vasodilatation to vascular endothelial growth factor (VEGF(165)) in collateral-dependent coronary arterioles. Interaction of VEGF receptor 2 (VEGFR-2) and the non-tyrosine-kinase receptor, neuropilin-1 has been reported to potentiate VEGF(165)-mediated signaling. In the current study, we tested the hypotheses that neuropilin-1 mediates the exercise-enhanced VEGF(165)-mediated vasodilatation in collateral-dependent arterioles and that neuropilin-1 and/or VEGFR-2 protein levels are increased in these arterioles. METHODS: Ameroid occluders were surgically placed around the proximal left circumflex coronary artery of miniature swine. Eight weeks after surgery, the animals were randomized into sedentary or exercise training (treadmill run; 5 days/week; 14 weeks) protocols. Coronary arterioles (approximately 100 microm diameter) were isolated from both collateral-dependent and control (left anterior descending) myocardial regions and studied by in vitro videomicroscopy or frozen for immunoblot analysis. RESULTS: Exercise-enhanced VEGF(165)-mediated vasodilatation in collateral-dependent arterioles was reversed by inhibition of the VEGF(165)-neuropilin-1 interaction. VEGF(121), which does not interact with neuropilin-1, induced similar vasodilatation in arterioles from all treatment groups. Immunoblot revealed significantly elevated VEGFR-1, VEGFR-2 and neuropilin-1 protein levels in collateral-dependent arterioles of exercise-trained pigs. CONCLUSIONS: Neuropilin-1 plays a vital role in the exercise-enhanced VEGF(165)-mediated vasodilatation of collateral-dependent coronary arterioles and is associated with increased neuropilin-1 receptor protein levels.

Exercise training enhances vasodilation responses to vascular endothelial growth factor in porcine coronary arterioles exposed to chronic coronary occlusion.

BACKGROUND: Chronic coronary occlusion (CCO) impairs endothelial function of distal collateral-dependent microvasculature; however, long-term exercise training (EX) seems to improve endothelial dysfunction. We hypothesized that EX enhances vasodilation responses to vascular endothelial growth factor (VEGF165), mediated via nitric oxide (NO), in arterioles exposed to CCO. METHODS AND RESULTS: The proximal left circumflex coronary artery (LCx) of female Yucatan miniswine was surgically instrumented with an ameroid occluder to induce CCO; 8 weeks after surgery, animals were randomized into 14-week sedentary (SED) or EX (treadmill; 5 d/wk) protocols. Coronary arterioles ( approximately 100 microm in diameter) were isolated from collateral-dependent (LCx) and nonoccluded (left anterior descending; LAD) perfused myocardium of SED and EX animals. Vasodilation was assessed by videomicroscopy and MacLab data acquisition. Responses to VEGF165 were unaffected by EX in nonoccluded LAD arterioles; in contrast, EX markedly enhanced VEGF165-induced vasodilation of collateral-dependent LCx arterioles (P<0.05; EX versus SED). Furthermore, VEGF165-induced vasodilation of EX LCx arterioles exceeded that of EX or SED LAD arterioles (P<0.05). Enhanced vasodilation of EX LCx arterioles was abolished by inhibition of NO synthase and tyrosine kinase activity. Combined inhibition of NO synthase and cyclooxygenase decreased VEGF165-induced vasodilation of all vessels. CONCLUSIONS: EX enhances VEGF165-induced vasodilation in arterioles distal to CCO; EX effects seem to be mediated through increases in NO.