Spinal Symptoms in Aviators and Their Relationship to Aircraft Types / 항공우주의학회지

BACKGROUND: By frequent G-exposures cervical and lumbar spinal symptoms may be the factors to limit their flying performance and causes of acute and chronic spinal diseases. We examined not only the frequency and degree of spinal symptoms but inter-relationship between these symptoms and several factors according to aircraft type. METHODS: We surveyed 244 ROKAF aviators by questionnaires attending aerospace-medical aviator physiology class of aeromedical center. RESULTS: Exposured gravities are 8.23, 6.02, 5.89 and 5.38 +Gz in pilots of F-16, F-5, F-4 and trainer aircraft respectively. Pilots of trainer aircraft were most frequently exposured to a gravity in a month. 72.5% of F-16 aviators had neck pain and 82.6% of trainer aircraft low back pain. Spinal symptoms limited checking 6 in about 55% of aviators and air combat maneuver in over 30% of aviators. CONCLUSION: To improve combat performance by alleviation of spinal symptoms aircraft aviators may rest sufficiently and had better keep a correct posture while +Gz exposures. We need to invent stretching exercises for relaxing muscle stress and correct seating frame of aircraft. Skilled medical team and instruments for physiotherapy also needed in airbases.

Effects of iontophoretically applied substance P, calcitonin gene-related peptide on excitability of dorsal horn neurones in rats

Spontaneous pain, allodynia and hyperalgesia are well known phenomena following peripheral nerve or tissue injury, and it is speculated that secondary hyperalgesia and allodynia, are generally thought to depend on a hyperexcitability (sensitization) of neurons in the dorsal horn. It is supposed that the sensitization may be due to various actions of neurotransmitters (SP, CGRP, excitatory amino acids) released from the primary afferent fibers. In this study, we examined effects of the iontophoretically applied SP and CGRP on the response to EAA receptor agonists (NMDA and non-NMDA) in the WDR dorsal horn neurones and see if the effects of SP or CGRP mimic the characteristic response pattern known in various pain models. The main results are summarized as follows: 1) SP specifically potentiated NMDA response. 2) CGRP non-specifically potentiated both NMDA and AMPA responses. Potentiation of NMDA response, however, was significantly greater than that of AMPA response. 3) 50% of SP applied cells and 15.8% of CGRP applied cells showed reciprocal changes(potentiation of NMDA response and suppression of AMPA response). These results are generally consistent with the sensitization characteristics in diverse pain models and suggests that the modulatory effects of SP and CGRP on NMDA and non-NMDA (AMPA) response are, at least in part, contribute to the development of sensitization in various pain models.

The effect of carbon monoxide on contraction, cytosolic Ca2+ level and ionic currents in guinea pig ileal smooth muscle

The aim of this study was to clarify the mechanism of the inhibitory action of carbon monoxide (CO) on contraction, by measuring cytosolic Ca2+ level ((Ca2+)i) and ionic currents in guinea-pig ileum. CO (10%) inhibited 40 mM KCl-induced contraction and this effect was blocked by ODQ (1 micrometer), a soluble guanylyl cyclase (sGC) inhibitor. CO inhibited the 40 mM KCl-induced contraction without changing (Ca2+)i. Cumulative addition of KCl induced a graded increase in (Ca2+)i and muscle tension. In the presence of CO, cumulative addition of KCl induced smaller contraction than in the absence of CO. On the other hand, the increase in (Ca2+)i induced by cumulative addition of KCl was only slightly decreased in the presence of CO, and the (Ca2+)i-tension relationship shifted downwards. Using the patch clamp technique with a holding potential of -60 mV, we found that CO had little effect on the peak Ba currents (IBa) when voltage was stepped from -60 mV to 0 mV. In addition, CO showed no effect on the depolarization-activated outward K+ currents in the all potential ranges. We conclude that CO inhibits smooth muscle contraction mainly by decreasing the Ca2+ sensitivity of contractile elements via a cGMP-dependent pathway, not by involving L-type Ca2+ and outward-potassium currents in guinea-pig ileum.