ABSTRACT
BACKGROUND@#We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO.@*METHODS@#We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM).@*RESULTS@#We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions.@*CONCLUSIONS@#These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.
Subject(s)
Animals , Male , Alveolar Epithelial Cells , Bronchi , Dose-Response Relationship, Drug , Emphysema , Epithelial Cells , Guinea Pigs , Hyperplasia , Inhalation Exposure , Lung , Pathology , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Myocytes, Smooth Muscle , Nitrous Acid , ToxicityABSTRACT
[Objective] To report the activity by the athletic trainer in a collegiate boxing club, focusing on acupuncture for medical treatment.<BR>[Methods] The athletic trainer was Japan a Japan Sports Association certifiedathletic trainer who was a practitioner of acupuncture and moxibustion. Subjects were twenty-seven collegiate boxers who participated for one year from April, 2004 to March, 2005.<BR>[Results] The activity by the athletic trainer was performed for thirty two days. Medical treatment was performed up to 2.2 times a day. Seventy-one people were treated by the athletic trainer. Medical treatments were acupuncture 28 (39.4%), massage 24 (33.8%), taping 4 (5.6%), and partner stretch 3 (4.2%). Thirteen people (48.1%) had acupuncture. In acupuncture, fifteen people (50%) had a chief complaint in the hand.<BR>[Discussion] Acupuncture was requested by the boxers. The continuation of the activity by the athletic trainer was required for boxing.