[Investigation and analysis of noise hazards in three key industries in Shenzhen City].

Objective: To understand the basic situation of noise hazards in wood furniture manufacturing, stone processing and special equipment manufacturing industries in Shenzhen City, and to provide basis for preventing and controlling noise hazards. Methods: In August 2019, stratified random sampling ws used to select 21 wood funiture manafacturing, 15 stone processing and 24 special equipment manufactruing as survey object. Through the methods of occupational health field investigation, noise intensity measurement and occupational health examination data collection, the noise hazards of 60 enterprises in three industries were statistically analyzed. Results: There were 154, 44 and 113 noise detection points in wood furniture manufacturing, stone processing and special equipment manufacturing enterprises, and 101, 27 and 78 out of standard points respectively, and the exceeding standard rates were 65.6% (101/154) , 61.4% (27/44) and 69.0% (78/113) , respectively. There were 1670, 172 and 856 workers exposed to noise in the three industries. Among them, 1198, 134 and 703 people had taken occupational health examination. The physical examination rates were 71.7% (1198/1670) , 77.9% (134/172) and 82.1% (703/856) , respectively. The abnormal rates were 19.1% (229/1198) , 51.5% (69/134) and 37.8% (266/703) , respectively. Conclusion: High intensity noise working environment, too long noise exposure time, incorrect wearing of personal protective equipment and neglect of occupational health examination are important reasons for hearing loss of noise exposed personnel.

[P(0) protein promotes the expression of INF-γ and IL-10 in peripheral blood of n-hexane neuropathy patients].

Objective: To study the changes of monocyte cytokines in peripheral blood of n-hexane neuropathy patients induced by P(0) protein, and to explore the role of autoimmunity in n-hexane neuropathy patients. Methods: In May 2018, 5 patients with peripheral neuropathy diagnosed as n-hexane poisoning were selected as case group in Shenzhen Prevention and Treatment Center for Occupational Disease in 2017. 6 workers exposure to n-hexane and 6 workers without n-hexane exposure were selected as contact group and control group. Peripheral blood mononuclear cells(PBMC) were isolated from venous blood. Results: The number of spots produced by INF-γ and IL-10 increased after stimulation with P(0) protein in case group, and the positive rate was significantly higher than control group and the contact group. Conclusion: Autoimmunity induced by P(0) protein may be involved in the occurrence of myelin sheath damage in n-hexane neuropathy patients.

Mild hypothermia attenuates post-resuscitation brain injury through a V-ATPase mechanism in a rat model of cardiac arrest.

Although therapeutic hypothermia is an effective treatment for post-resuscitation brain injury after cardiac arrest (CA), the underlying mechanism remains unclear. Vacuolar H(+)-ATPase (V-ATPase) plays a key role in cellular adaption to a hypoxic environment. This study sought to evaluate the effect of mild hypothermia on V-ATPase and its involvement in neuroprotection after CA. Male Sprague-Dawley rats were subjected to a 6-min CA, resuscitated successfully, and then assigned to either the normothermia (NT) group or the hypothermia (HT) group. Rats were further divided into 2 subgroups based on the time of euthanasia, either 3 or 24 h after CA (NT-3 h, HT-3 h; NT-24 h, HT-24 h). Mild hypothermia was induced following CA and maintained at 33°C for 2 h. Neurologic deficit scores were used to determine the status of neurological function. Brain specimens were analyzed by TUNEL assay, western blotting, and immunohistochemistry. V-ATPase activity was estimated by subtracting total ATP hydrolysis from the bafilomycin-sensitive activity. Mild hypothermia improved the neurological outcome (HT-24 h: 34.3 ± 16.4 vs NT-24 h: 50.3 ± 17.4) and significantly decreased neurocyte apoptosis 24 h after resuscitation. Mild hypothermia significantly increased V0a1 compared to NT-3 h; V0a1 expression was associated with a decrease in the cleaved caspase 3 expression. These findings suggested that mild hypothermia inhibits CA-induced apoptosis in the hippocampus, which may be associated with reduced V-ATPase impairment. These data provide new insights into the protective effects of hypothermia in vivo.

[Influence of cigarette smoking on the hypoxic pulmonary vasoconstriction in isolated rat lungs--the role of prostaglandins and leukotrienes]. / Der Einfluss des Rauchens auf die hypoxische pulmonale Vasokonstriktion in der isolierten Lunge der Ratte--die Rolle der Prostaglandine und Leukotriene.

Isolated rat lungs perfused with blood were used to determine the effects of cigarette smoke, delivered into the lung by a ventilator, on the pulmonary vascular resistance (PVR), and on the hypoxic pulmonary vasoconstriction (HPV), and to explore the role the prostaglandins (PG) and leukotrienes (LT) play in that effect. The results showed that PVR did not change, while HPV was significantly enhanced by smoking. Indomethacin, an inhibitor of PG biosynthesis, administered in the perfusing blood (20 micrograms/ml) increased HPV in non-smoking lungs, but not in lungs after smoking. Diethylcarbamazine citrate (DEC; 1 mg/ml), an inhibitor of LT biosynthesis, decreased HPV before and after smoking. After perfusion with both indomethacin and DEC, HPV also decreased. It is suggested that LT act as mediators whereas PG as modulators in HPV, and PG and LT might play an important role in the increase of HPV by cigarette smoking.

Biomechanical characteristics of human trabecular bone.

OBJECTIVE: To evaluate the effect of strain rate (varepsilon), apparent density (rho(a)) and tissue density (rho(t)) on Young's modulus (E), strength (sigma(u)) and ultimate strain (varepsilon(u)) on intervertebral bone from a Chinese population. METHODS: Testing was performed by uniaxial compression at five strain rates on 36 human trabecular bone specimens from three male T(12) thick similar L(4) vertebrae. RESULTS: Apparent density ranged between 0.46 and 0.71 g/cm(3). Tissue density ranged between 1.02 and 1.54 g/cm(3). Non-linear regression analyses using strength, Young's modulus or ultimate strain as dependent variables (Y) and strain rate and apparent density or tissue density as independent variables were performed using the following equation: Y = arho(b)varepsilon(c). The exponent of apparent density and strain rate to Young's modulus were 1.88 and 0.07, separately (P = 0.0007). The variation of strength was explained only by apparent density with an exponent of 1.29 (P = 0.0107). The variation of Young's modulus was explained equally by the quadratic and cubic relationship to apparent density or tissue density (P < 0.01). Ultimate strain varied independently of apparent density or tissue density and strain rate.

Strain difference in pulmonary vascular responsiveness to hypoxia in rats.

The difference in pulmonary vascular response to hypoxia between Hilltop Sprague-Dawley (HT) rats and Wistar (W) rats was studied. Effects of inhibitor of leukotriene (LT) synthesis or prostaglandin (PG) synthesis on hypoxic pulmonary vasoconstriction (HPV) and chronic pulmonary hypertension were observed, and variations in plasma TXB2 and 6-keto-PGF1 alpha during hypoxia were determined. The results showed that in rats of both strains LTs are the major mediator of HPV, which is also mediated by vasoconstrictive PGs in HT rats, while modulated by vasodilative PGs in W rats. This might be the crucial mechanism responsible for the higher pulmonary vascular responsiveness in HT rats. Differences in the modulating effect of histamine and in the structural feature of pulmonary arteriole might be contributing factors as well.