Aerospace nutrition and food hygiene is a subject elucidating the effect of aerospace envi-ronment on nutrition and food hygiene which is closely related to health of flight personnel. The teaching work should be in the aim of raising battle effectiveness and enforcing the primary professional capability of students. The most required theory and techniques in both peacetime and wartime was the priority of teach-ing fulfilling mainly through practical or in-site learning. The examination was composed of test paper, ex-periments and health propaganda. The teaching evaluation relied on feed-back of the army on which the teaching plan was revised. Survey in three straight years indicated the exploration enhanced teaching quality significantly.

BACKGROUND: In clinical practice, delayed brain injury after carbon monoxide (CO) poisoning occurs in 3% to 30% of the persons who suffered carbon monoxide poisoning and is in the main presence of dementia, psychiatric symptom and extrapyramidal symptoms. At present, its pathogenesis is unclear.OBJECTIVE: To investigate the pathological damage mechanism of delayed brain injury after CO poisoning and the protective effect of hyperbaric oxygen on delayed brain injury.DESIGN: A randomized controlled animal experiment.SETTING: Staff Room of Aviation Health, Department of Aerospace Medicine, the Fourth Military Medical University of Chinese PLA.MATERIALS: This experiment was carried out in the Laboratory of Aviation Pathology and Molecular Biology, Department of Aerospace Medicine, the Fourth Military Medical University of Chinese PLA in March 2004. Totally 80 healthy male Sprague-Dawley, of clean grade, were used in this experiment. The animals were randomized into 3 groups: normal control group (n=10), model group (n=35) and hyperbaric oxygen group (n=35).The latter two groups were separately divided into 7 time points: poisoning 6 hours, 1,3,5,7,14 and 21 days, 5 rats at each time point.METHODS: In the model group, acute CO poisoning rat models were developed by placing the rats in the poisoning jar which contained the mixture of CO and air for 60 minutes. The volume faction of CO was kept at 2 500×10-6. In the hyperbaric oxygen group, modeling was the same as that in the model group. Three hours after poisoning, the rats were given 115-minute hyperbaric oxygen treatment. Pressure was 0.2 Mpa and the volume fraction of oxygen was over 0.90. The first three days after poisoning, hyperbaric oxygen treatment was conducted twice per day, then once per day, with one day of non-administration in a week. There was no intervention in the normal control group. MAIN OUTCOME MEASURES: ① The characters of pathological changes in brain tissue of rats at each time point after poisoning were detected with histopathological and immunohistochemical methods; ② Neuronal apoptosis was detected with electron microscopy and in situ TdT-mediated-dUTP nick end labeling(TUNEL).RESULTS: After rats were modeled, the rate of death was about 10%. ① In the model group, general pathological injury occurred in the brains of rats. Denatured necrosis appeared in the neurons of cerebral cortex, hippocampus, corpus striatum, cerebellum and other regions. Injuries in cerebral cortex, hippocampus and other regions were severe. Results of haematoxylin-eosin and TUNEL staining and electron microscope observation demonstrated that apoptosis occurred in hippocampal neurons. The apop totic neurons increased on the 3rd day after poisoning, reached the peak on the 7th day (P ＜ 0.01), then gradually decreased. In the hyperbaric oxygen group, the denatured necrosis of neurons in the brains was significantly lightened, and the injuries of hippocampal region of rats at each time point were significantly attenuated in comparison with model group; The number of necrotic neurons was decreased, especially on the 5th and 7th days after poisoning (P ＜ 0.01). Hyperbaric oxygen promoted the expression of Bcl-2 in hippocampus of modeled rats, especially on the 3rd and 5th days after Coexposure (P ＜ 0.01).CONCLUSION: General delayed neuronal injury is found in the acute CO poisoning rat, with the presence of delayed neuronal necrosis and apoptosis. Hyperbaric oxygen treatment can effectively reduce denatured and necrotic neurons and promote the expression of apoptosis-inhibiting gene bcl-2, then inhibit neuronal necrosis and apoptosis.

Objective To explore the feasibility of team-based learning (TBL) for practice teaching of the aerospace nutrition and food hygiene.Methods A total of 90 students were investigated,and were divided into the TBL group (n=46) and the TL group (n=44) by simple random sampling.After the experiment teaching,a test and questionnaire were used to compare the teaching effect of TBL group and TL group.SPSS 18.0 was used for date and the data was analyzed by Independent-Samples t test and Chi-square test.Results Students in TBL group achieved higher mean test scores (85.70 ± 3.47) compared with students (74.10±2.41) in TL group and the difference was statistically significant (t=8.703,P=0.000).The results of the questionnaire showed that,compared with the TL group,TBL group students more agreed with the positive impact of the teaching methods on their team work ability,interpersonal skills,communication ability,problem-solving and self-learning and other aspects,and the differences between two groups were statistically significant (P＜0.05).In addition,the majority of the respondents in TBL group [93.5％ (43/46)] were satisfied with TBL.Conclusions TBL teaching is better than the TL teaching,and it can significantly improve students' comprehension of knowledge and enhance their learning effect.

Objective:To investigate the changes of gene or protein expression and activity of matrix metalloprotein9 (MMP9) and tissue inhibitor ofmetalloproteinasel (TIMP1) in the carotid artery (CA) of 4 wk hindlimb unweighted rat.Methods:A 4 weeks(wk) hindlimb unweighted (HU) rat model was used to simulate the effect of weightlessness on the cardiovascular system.Transmission electron microscopy was used to detect the content of ECM.Reverse transcriptase polymerase chain reaction(RT-PCR) was conducted to measure the mRNA content MMP and TIMP1.Immunohistochemistry and Western blot technique were used to measure the protein abundance.Gelatin zymography was carried out to detect the activity of MMP9.Results:Compared to the control group (CON),the area of ECM was enhanced (P＜0.05) and the content of collage fiber was increased (P＜0.05) in the CA of HU rats;moreover,HU did not affect the mRNA expression of MMP9,but significantly reduced the protein content (P＜0.05) or enzymatic activity (P＜0.05).Accordingly,the mRNA or protein expression of TIMP1 in the CA was significantly increased by HU (P＜0.05).Conclusion:Simulated weightlessness caused imbalance between MMP and TIMP1 expression,which might contribute to the ECM aggregation and stiffness of CA.

Hyperbaric oxygen (HBO) medicine is an applied interdiscipline concerning basic me-dicine,clinical medicine,physics and psychology.Indications of HBO treatment involve multiple systems of the body.Based on the practice of almost 30 years,we explore how to adopt heuristic and experiencing style to strengthen the combination of theory and clinical application fortifying practical operation in the teaching. Meanwhile,discussing obstacles in HBO treatment and learning frontiers and progress through literatures or animal experiments can cultivate students' solid theoretical foundation and basic analysis and operation skills,and improve their interest in clinical and scientific research work of hyperbaric oxygen.

Military flying labor hygiene is a discipline that focuses on influences of special flight environment and labor condition on human body and related prevent measures, with the core of flight fatigue. Health information and technique training can help flight surgeons to enhance professional competency and improve the prevention and recovery of military flying fatigue. The course construction of teaching system in this study included survey of demand, arrangement of content, identification of strategy, determination of evaluation, and feedback of results. Meanwhile, the textbook compilation, cultivation of teaching team and construction of laboratory were also needed. After a 4-year practice, a formal teaching system has been established and its teaching effectiveness has basically fulfilled the professional requirement for flight surgeons.