Subjective and objective convergence of the eyes at simulated altitude of 18,000 feet Preceded by short-term exposure to heat stress.

Armed forces personnel including military aviators are quite often exposed concurrently to various environmental stressors like high environmental temperature and hypoxia. Literatures have suggested that exposure to one environmental stressor may modify the physiological response on subsequent exposure to same or different stressor. The present study was undertaken to investigate the impact of cross tolerance between two environmental stressors of aviation (heat and hypoxia) in ten healthy adult males in a simulated altitude chamber in a within subject experimental study. They were assessed for their convergence ability of the eyes at ground and at simulated altitude of 18,000 ft with or without pre-exposure to heat stress. Subjective convergence at simulated altitude of 18,000 ft did not show any improvement following pre-exposure to heat stress. Objective convergence was improved following pre-exposure to heat stress and was found to be 10.76 cm and 9.10 cm without and with heat stress respectively at simulated altitude of 18,000 ft. Improved objective convergence at high altitude as a result of pre-exposure to heat stress is indicative of better ocular functions. This might benefit aviators while flying at hypoxic condition.

Obesity Affects Median Nerve Conduction - A Study in Armed Forces Individuals.

Background: Obesity, a growing public health concern, is associated with various disorders. Studies have suggested obesity as an independent risk factor that influences the prevalence of carpal tunnel syndrome (CTS) among active workers. The present study is an attempt to establish relationship between median nerve conduction velocity and obesity in people who do not have any other contributory factor for CTS other than obesity. CTS is the commonest entrapment neuropathy where the median nerve is compressed. Methods: The study was conducted in 15 obese subjects with Body Mass Index (BMI)>30 (group III) and 15 overweight subjects with BMI between 25&29.9 (group II) and 15 control subjects with BMI <25 (group I). The subjects were personnel from armed forces. Their body density was estimated using hydro-densitometry and the body fat percentage was calculated from density. The distal motor latency (DML) and the sensory conduction velocity (SCV) across the wrist on stimulation of median nerve at wrist 3cm proximal to distal crease were assessed in all subjects. Results: The mean values of DML in group I, II, and III were 3.52±0.25 ms, 3.50±0.30 ms and 3.65±0.20 ms respectively. Mean value of SCV among these groups were 48.99±3.23 m/s, 49.32±3.35 m/s and 48.69±4.00 m/s. Conclusion: No relationship could be established between BMI and DML as well as BMI and SCV. The relationship between percentage body fat and DML and SCV also found to be statistically insignificant. However, there was a correlation between BMI and body fat percentage. Carpal tunnel syndrome is uncommon even in obese armed forces personnel, which might be due to their regular body and hand exercise thereby having increased tone in hand muscles.

Antidotal efficacy of pyridinium oximes and cholineacetyltransferase inhibitors against organophosphorus intoxication in rodents.

In an attempt to develop effective antidote against organophosphorus intoxication, some new imidazole-pyridinium mono-oximes, long chain pyridinium mono-oximes and cholineacetyltransferase inhibitors were synthesised. These compounds were evaluated for their in vivo therapeutic protection and neuromuscular function studies in rodents. The results indicate that SPK-series oximes may be useful against sarin poisoning without any beneficial effect against VX (O-Ethyl S-2-NN-diisopropylaminoethyl methylphosphonofluoridate) intoxication. The cholineacetyltransferase (ChAT) inhibitors may not be of any help against any of the OP compounds studied in this study.