Riding (High) into the danger zone: a review of potential differences in chemical exposures in fighter pilots resulting from high altitude and G-forces

Military Aviators with Inflammatory Bowel Diseases Continued Flying

INTRODUCTION: Military aviators are likely to be first diagnosed with inflammatory bowel diseases (IBD) during military service. Current recommendations support continuing flying with restrictions, but risks may be significant. The aim of the study was to document the long-term results of aviators newly diagnosed with IBD. METHODS: A prospective observational study over a 23-yr period included all Israeli Air Force (IAF) aviators with IBD. Primary end point was the qualification and safety to continue operational flying following IBD diagnosis. RESULTS: Subjects were 16 male aviators with an average follow-up of 130 mo. Average age was 27 (2045) and average time from symptoms onset to final diagnosis was 7.3 mo. Eight (50%) patients had Crohns disease (CD), and the other eight had ulcerative colitis (UC). Eight (50%) were high performance platform aviators. Two patients received biologic treatment, two were treated with repeated corticosteroid courses, and four with immunosuppressive therapy. Two patients underwent surgery and four needed different lengths of hospitalizations. Eight (50%) aviators (3 CD, 5 UC) were grounded for a mean of 177 d (5590). Altogether grounding for IBD aviators was 46/2087 mo (2.2%). Most grounding periods were short term and reversible. All aviators continued flying under annual monitoring or as needed and no compromise of their abilities was documented. CONCLUSIONS: All aviators were able to continue flying and no events of sudden incapacitation or severe disabling flares have been seen among patients. Our study findings support the current recommendation to continue flying when IBD is in stable remission. Tehori O, Koslowsky B, Gabbai D, Shapira S, Ben-Ari O. Military aviators with inflammatory bowel diseases continued flying. Aerosp Med Hum Perform. 2021; 92(10):831834.

Novel Approach for Detecting the Neurological or Behavioral Impact of Physiological Episodes (PEs) in Military Aircraft Crews

Introduction

Military and civil aviation have documented physiological episodes among aircrews. Therefore, continued efforts are being made to improve the internal environment. Studies have shown that exposures to many organic compounds present in emissions are known to cause a variety of physiological symptoms. We hypothesize that these compounds may reversibly inhibit acetylcholinesterase, which may disrupt synaptic signaling. As a result, neural proteins leak through the damaged blood-brain barrier into the blood and in some, elicit an autoimmune response.

Materials and Methods

Neural-specific autoantibodies of immunoglobulin-G (IgG) class were estimated by the Western blotting technique in the sera of 26 aircrew members and compared with the sera of 19 normal healthy nonaircrew members, used as controls.

Results

We found significantly elevated levels of circulating IgG-class autoantibodies to neurofilament triplet proteins, tubulin, microtubule-associated tau proteins (Tau), microtubule-associated protein-2, myelin basic protein, and glial fibrillary acidic protein, but not S100 calcium-binding protein B compared to healthy controls.

Conclusion

Repetitive physiological episodes may initiate cellular injury, leading to neuronal degeneration in selected individuals. Diagnosis and intervention should occur at early postinjury periods. Use of blood-based biomarkers to assess subclinical brain injury would help in both diagnosis and treatment.

Effect of different combat jet manoeuvres in the psychophysiological response of professional pilots

Extreme limits of the human body could be reached in air combat. We analysed 29 fighter pilots before and after offensive and defensive manoeuvres on heart rate (HR), heart rate variability, leg and hand strength, spirometry, temperature, blood oxygen saturation (BOS), lactate, hydration (USG), cortical activation, memory and psychological variables. The defensive manoeuvre produced a significative decrease in forced vital capacity from spirometry and USG post flight, a moderate effect in the decrease in cognitive anxiety and an increase in leg strength. A significant increase in mean HR and an increase with a large effect size was reported for Stress Subjective Perception and Rating of Perceived Exertion in both manoeuvres. With this data we can conclude that high level of physical fitness and specific training programs should be applied to fighter pilots.

The gravity dependence of pharmacodynamics: the integration of lidocaine into membranes in microgravity

To realize long-term manned space missions, e.g. to Mars, some important questions about pharmacology under conditions of different gravity will have to be answered to ensure safe usage of pharmaceuticals. Experiments on the International Space Station showed that the pharmacokinetics of drugs are changed in microgravity. On Earth, it is well known that the incorporation of substances into cellular membranes depends on membrane fluidity, therefore the finding that membrane fluidity is gravity dependent possibly has effects on pharmacodynamics of hydrophobic and amphiphilic substances in microgravity. To validate a possible effect of gravity on pharmacodynamics, experiments have been carried out to investigate the incorporation of lidocaine into plain lipid membranes under microgravity conditions. In microgravity, the induced increase in membrane fluidity associated with lidocaine incorporation is smaller compared to 1g controls. This experiment concerning the gravity dependence of pharmacodynamics in real microgravity clearly shows that the incorporation of amphipathic drugs into membranes is changed in microgravity. This might have significant impact on the pharmacology of drugs during long-term space missions and has to be investigated in more detail to be able to assess possible risks.

Chemically Enhanced Polymer-Coated Carbon Nanotube Electronic Gas Sensor for Isopropyl Alcohol Detection

Breathing-air quality within commercial airline cabins has come under increased scrutiny because of the identification of volatile organic compounds (VOCs) from the engine bleed air used to provide oxygen to cabins. Ideally, a sensor would be placed within the bleed air pipe itself, enabling detection before it permeated through and contaminated the entire cabin. Current gas-phase sensors suffer from issues with selectivity, do not have the appropriate form factor, or are too complex for commercial deployment. Here, we chose isopropyl alcohol (IPA), a main component of de-icer spray used in the aerospace community, as a target analyte: IPA exposure has been hypothesized to be a key component of aerotoxic syndrome in pre, during, and postflight. IPAs proposed mechanism of action is that of an anesthetic and central nervous system depressant. In this work, we describe IPA sensor development by showing (1) the integration of a polymer as an IPA capture matrix, (2) the adoption of a redox chemical additives as an IPA oxidizer, and (3) the application of carbon nanotubes as an electronic sensing conduit. We demonstrate the ability to not only detect IPA at 100-10 000 ppm in unfiltered, laboratory air but also discriminate among IPA, isoprene, and acetone, especially in comparison to a typical photoionization detector. Overall, we show an electronic device that operates at room temperature and responds preferentially to IPA, where the increase in the resistance corresponds directly to the concentration of IPA. Ultimately, this study opens up the pathway to selective electronic sensors that can enable real-time monitoring in a variety of environments for the force health prevention and protection, and the potential through future work to enable low parts-per-million and possibly high parts-per-billion selective detection of gas-phase VOCs of interest.