人工富氧环境改善急进高原人员睡眠效果的研究

Objective To study the effects of the artificial oxygen-enriched environment (is called "oxygen-enriched room" in short) on sleep efficiency of the people who participate in the mission on plateau with hurry-up entry,and to investigate the anti-hypoxia effect of oxygen-enriched room to plateau acclimatization. Methods Eighteen subjects were randomly and averagety allocated into plain group,oxygen-enriched group and hypoxia group.Only the later two groups were dispatched to plateau by air.Molecular sieve oxygenerator was used to supply the room with oxygen on 3500 m plateau.The oxygen-enriched group and hypoxia group got into the oxygen-enriched rooms and normal rooms respectively at 22 o' clock and took rest till to 9 o' clock next morning.The changes of heart rate (HR) and the saturation of blood oxygen (SaO2) of three groups were recorded and compared between the states of with and without oxygen enrichment.The subjects were monitored by sleep respiration recording and analysis system. Results ①The SaO2 of the oxygen-enriched group was 92.3%±1.0%,and it was significant higher than the state before oxygen enrichment (82.9%±4.2%) and than that of hypoxia group (79.3%±5.9%,P<0.01),but lower than that of plain group (97.3%±0.8%,P<0.05).②There were less deep sleep and more slight sleep in hypoxia group and oxygen-enriched group than in plain group.The hypopnea and apnea hypopnea index (AHI) of plain group was significant lower than that of hypoxia group and oxygen-enriched group (P<0.05).The AHI of the oxygen-enriched group was 28.1±11.9,and it was significant lower than that of hypoxia group (53.2±23.4)(P<0.05).③The normalized low-frequency (Ln) and the ratio of low-frequency to high-frequency (LF/HF) measured in sleep was respectively 89.3±2.9 and 6.4±1.4 in oxygen-enriched group comparing to 90.2±1.8 and 9.9±1.9 in hypoxia group but without statistical difference.The corresponding Ln and LF/HF of plain group was 85.8±2.9 and 6.4±1.4 respectively,significantly higher than those of other two groups (P<0.05).Plain group also showed higher normalized high-frequency than others(P<0.05). Conclusions Oxygen-enriched environment can effectively improve the sleep quality but significantly change heart rate variation (HRV) of the people who participate in the mission with hurry-up entry to plateau.Further studies are still needed to reveal the quantitative effectiveness of oxygen-enriched room to plateau acclimatization.     

预先心理应激对干舱模拟快速上浮脱险大鼠应激反应的作用

Objective To observe the effects of psychological pretreatment on the stress reaction of simulated fast buoyancy ascent escape in rats. Methods Forty healthy rats were randomly divided into 4 groups:the control group, the psychological stress group, the fast compression and decompression group, and the psychological stress pretreatment plus fast compression and decompression group. By developing the fast buoyancy ascent escape rat model with fast compression and decompression in a closed cabin, the effects of psychological pretreatment on the stress reaction were observed in the course of ascent. Results Hear t rate of the animals in the psychological pretreatment stress group was significantly higher than that in the control group (P＜0. 05), and the expression of serum TNF-α was significantly lower than that in the control group (P ＜ 0.05 ). Conclusions Psychological factor seemed to have positive effects on the stress reaction of the simulated fast buoyancy ascent escape in rats.     

氮氧自由基R-1对人肝细胞L-02的辐射防护作用

Objcetive To investigate the protective effects of the nitroxides R-1 on human liver cells exposed to ionizing radiation.Methods Human liver cells L-02 were cultured and irradiated with 60Co γ-rays at the doses of 0,1,2,4,and 8 Gy,in order to screen the proper irradiation dose.WR2721 at the terminal concentration of 4 mmol/L was used as positive control.L-02 cells irradiated with 4 Gy were added with R-1 at the terminal concentration of 0.25 μmol/L at 30 min before irradiation or immediately after irradiation.MIT method was used to screen the proper conditions for follow-up experiment 72 h later.L-02 cell culture fluid was added with R-1 at the concentrations of 0,0.125,0.25,0.5,and 1 μmol/L,respectively for 30 min before irradiation at the doses of 0,1,2,4,and 8 Gy to ealculate clone formation rate at 10 d post-irradiation.L-02 cells were cultured and divided into 4 groups:control group without any treatment.drug group pretreated by 0.25 μmol/L R-1 only,irradiation group,irradiated at 4 Gy only,and drug + irradiation group with combination of 0.25 μmol/L R-01 and 4 Gy irradiation.The inverted microscopy and Hoechst 33258 staining and flow eytometry were used to observe the apoptosis of the cells at 24,48,and 72 h later.Results Nitroxides R-1 did not inhibit the viability of L-02 cell when its concentration was less than 1 μmol/L and it inhibited the L-02 cell growth when the concentration wu higher than 2 μmoL/L.The A value and colony formation rate of different concentration of R-1 groups were all higher than those of the irradiation group,and the effect of the 0.25 μmol/L drug concentration group was the most significant.Consequently,the concentration 0.25 μmoL/L was selected for follow-up experiment.Compared with the irradiation group,the L-02 cells of the pretreatment group showed solid adherence, increased refraction,clear outline,less apoptotic and dead cells at 4 Gy post-irradiation.Conclusions Nitroxides R-1 can protect the human liver cells from 60Coγ-ray induced injury effectively.The mechanism of its protective effect may be the reduction of apoptosis.     

辛伐他汀预处理减轻缺血再灌注心肌损伤的实验研究

Objective To investigate the effects of pretreatment with simvastatin on iscbemia reperfusion induced myocardial injury, and to further explore related mechanism with respect to inflammation modulation. Methods The rat myocardial ischemia reperfusion model was established by the method of coronary artery ligation. The animals were divided into 3 groups: the sham group, the control group and the simvastatin group. In the simvastatin group, the animals were pretreated with simvastatin (5 mg/kg) one week before by intragastric administration. Ventricular arrhythmia was monitored and scored, infarct size and area at risk of myocardium were determined, and uhrastructural changes were observed. The serum levels of myocardial enzymes and lipids were measured. The content of myocardial inflammatory cytokines [tumor necrosis factor (TNF) -α、interleukin(IL) -6, and monocyte chemoattractant protein(MCP) - 1]were also evaluated. Results When compared with those of the control group, the amount and duration of ventricular arrhythmia in simvastatin group were less and score of ventricular arrhythmia was significantly lower. When pretreated with simvastatin, the serum levels of CK-MB and LDH in simvastatin group were significantly lower than those of the control group. The infarct size/area at risk ratio of the simvastatin treated group was significantly less than those of the control group. The uhrastructures of myocardial cells were better maintained in simvastatin group. No significant differences were observed in the serum concentrations of total cholesterol, triglycerides, low density lipoprotein and high density lipoprotein when comparisons were made each other among the three groups. However, the levels of TNF-α,IL-6 and MCP-1 in heart tissue of the treated animals were significantly lower than those of the control group. Conclusions Pretreatment with simvastatin ameliorates ischemia reperfusion induced myocardial injury, which is partly related with the down-regulation of inflammatory cytokines expression in heart tissue but independent of its role of lipids modulation.     

辛伐他汀预处理减轻缺血再灌注心肌损伤的实验研究

Objective To investigate the effects of pretreatment with simvastatin on iscbemia reperfusion induced myocardial injury, and to further explore related mechanism with respect to inflammation modulation. Methods The rat myocardial ischemia reperfusion model was established by the method of coronary artery ligation. The animals were divided into 3 groups: the sham group, the control group and the simvastatin group. In the simvastatin group, the animals were pretreated with simvastatin (5 mg/kg) one week before by intragastric administration. Ventricular arrhythmia was monitored and scored, infarct size and area at risk of myocardium were determined, and uhrastructural changes were observed. The serum levels of myocardial enzymes and lipids were measured. The content of myocardial inflammatory cytokines [tumor necrosis factor (TNF) -α、interleukin(IL) -6, and monocyte chemoattractant protein(MCP) - 1]were also evaluated. Results When compared with those of the control group, the amount and duration of ventricular arrhythmia in simvastatin group were less and score of ventricular arrhythmia was significantly lower. When pretreated with simvastatin, the serum levels of CK-MB and LDH in simvastatin group were significantly lower than those of the control group. The infarct size/area at risk ratio of the simvastatin treated group was significantly less than those of the control group. The uhrastructures of myocardial cells were better maintained in simvastatin group. No significant differences were observed in the serum concentrations of total cholesterol, triglycerides, low density lipoprotein and high density lipoprotein when comparisons were made each other among the three groups. However, the levels of TNF-α,IL-6 and MCP-1 in heart tissue of the treated animals were significantly lower than those of the control group. Conclusions Pretreatment with simvastatin ameliorates ischemia reperfusion induced myocardial injury, which is partly related with the down-regulation of inflammatory cytokines expression in heart tissue but independent of its role of lipids modulation.     

神经生长因子基因转染联合强化铁营养防治豚鼠爆震性聋的实验研究

Objective To study the protective effects of adenovirus-mediated human beta-nerve growth factor gene (hNGFβ) transfer combined with iron fortified nutrition on blast hearing damage in guinea pigs. Methods Deafness was induced by blast (172dB SPL) in 35 healthy guinea pigs. Seven days after noise exposure, 10 guinea pigs were inoculated with adenovirus-mediated hNGFβ (Ad-hNGFβ) into the perilymphatic space (the gene group), another 10 guinea pigs were given hNGFβ combined with iron fortified nutritional diet (the combination group), still another 10 guinea pigs were inoculated with artificial perilymphatic fluid (APF), and 5 guinea pigs served as control, given neither medicine nor noise exposure. Auditory brainstem response (ABR) threshold shifts were monitored in the guinea pigs before blast exposure and after gene transfer. Changes in cochlear morphology were examined with immunohistochemical and HE staining. Results One week after successful inoculation of hNGFβ, it was noted that Ad-hNGFβ protein was expressed in each turn of the cochlea, and its intensity was almost equal. After gene transfer in the combination group and the gene group, ABR threshold shifts at week 1 and 4 were significantly smaller than those of the APF group. HE staining showed that the number of the spiral ganglion cells in the combination group and the Ad-hNGFβ group was significantly higher than that of the control group after 4 weeks (P<0.01). Conclusions Ad-hNGFβ combined with iron fortified nutritional diet was effective in the prevention and treatment of blast hearing damage of cochlear hair cells.     

神经生长因子基因转染联合强化铁营养防治豚鼠爆震性聋的实验研究

Objective To study the protective effects of adenovirus-mediated human beta-nerve growth factor gene (hNGFβ) transfer combined with iron fortified nutrition on blast hearing damage in guinea pigs. Methods Deafness was induced by blast (172dB SPL) in 35 healthy guinea pigs. Seven days after noise exposure, 10 guinea pigs were inoculated with adenovirus-mediated hNGFβ (Ad-hNGFβ) into the perilymphatic space (the gene group), another 10 guinea pigs were given hNGFβ combined with iron fortified nutritional diet (the combination group), still another 10 guinea pigs were inoculated with artificial perilymphatic fluid (APF), and 5 guinea pigs served as control, given neither medicine nor noise exposure. Auditory brainstem response (ABR) threshold shifts were monitored in the guinea pigs before blast exposure and after gene transfer. Changes in cochlear morphology were examined with immunohistochemical and HE staining. Results One week after successful inoculation of hNGFβ, it was noted that Ad-hNGFβ protein was expressed in each turn of the cochlea, and its intensity was almost equal. After gene transfer in the combination group and the gene group, ABR threshold shifts at week 1 and 4 were significantly smaller than those of the APF group. HE staining showed that the number of the spiral ganglion cells in the combination group and the Ad-hNGFβ group was significantly higher than that of the control group after 4 weeks (P<0.01). Conclusions Ad-hNGFβ combined with iron fortified nutritional diet was effective in the prevention and treatment of blast hearing damage of cochlear hair cells.     

亚低温对急性重型颅脑损伤患者血清S-100 B蛋白的影响

Objective To dynamically observe the effect of mild hypothermia on concentration of plasma S-100B protein in patients with acute severe brain injuries so as to further explore its role in treat-ment of acute severe brain injury. Methods A total of 120 patients with acute severe brain injuries were randomly divided into mild hypothermia group and general group. The patients in mild hypothermia group were treated with mild hypothermia besides conventional therapy, with maintenance of rectal tem-perature at 33℃-35℃ for 3-5 days. Serial concentration of S-IOOB protein in serum was measured in all patients from 6 hours to 6 days after hospitalization. GOS evaluation was done three months after treat-ment. Results The concentration of S-100B protein in serum of mild hypothermia group and general group was significantly higher than of normal group (P <0.05), with significant lower level in mild hypo-thermia group than general group(P <0.05). Mild hypothermia could improve prognosis of patients with acute severe brain injury. Conclusions Early use of mild hypothermia can decrease concentration of S-100B protein in serum, protect neurofunction and improve prognosis, as may be related to its function in alleviating damnification brain cell inflammation reaction mediated by S-100B protein.