Environmental Exposure ; adverse effects ; Hearing Loss ; etiology ; Humans ; Noise, Occupational ; adverse effects ; Occupational Diseases ; etiology ; Occupational Exposure ; adverse effects ; Risk Factors ; Smoking ; adverse effects ; Vibration ; adverse effects

Osteoblasts are the most important mechanoreceptive and osteogenic cells.The loss of bone in microgravity is mainly due to the dysfunction of osteoblasts.Research on osteoblast cytology under simulated weightlessness has made great progress in recent years.Current experiments are focusing on the changes in the cellular proliferation,differentiation,apoptosis, function and signal transduction in osteoblasts.This paper reviews the progress of the studies in this field.

Humans ; Noise, Occupational ; adverse effects ; Occupational Exposure ; standards

Objective To investigate the effect of sodium arsenite combined with cigarette smoke solution on NF-?B in rat lymphocytes. Methods Rat lymphocytes were divided into 4 groups: the arsenite treatment group, the CSS treatment group, the arsenite and CSS treatment group, and the control group. Electrophoretic mobility shift assays was used to detect levels of NF-?B DNA binding. Western blot was used to detect protein expression of I?B?. Results Levels of NF-?B DNA binding in the CSS treatment group and the arsenite treatment group were significantly increased (P

Hepatic tumor-specific magnetic resonance (MR) enhancement with Gd-EOB-DTPA can detect and distinguish small hepatocellular carcinoma (HCC) with greater sensitivity than conventional magnetic resonance imaging and computed tomography.Hepatic tumor-specific MR enhancement with Gd-EOB-DTPA is more sensitive in detecting focal HCC,and more reliable in detecting lesions with a diameter smaller than 2cm.Gd-EOB-DTPA is excreted through the kidneys and biliary tract,and thus may provide more information about anatomic structures,demonstrate non-obstruction of the intra- and extrahepatic bile duct system,and provide information about hepatic function.

Objective · To compare the short and medium-term efficiency and safety of 1470 nm laser with foam sclerotherapy with ligation of great saphenous vein and 808 nm laser with foam sclerotherapy to treat varicose veins of lower extremity. Methods · Seventy-seven hospitalized patients patients and twenty-one day-surgery patients were retrospectively analyzed. Results · There was no obvious difference in the closure of great saphenous vein for short to medium-term efficiency between the day-surgery group and hospitalized group. The postoperative complications and recurrence rate of day-surgery group was not higher than that of the hospitalized group, but the degree of perioperative comfort, economic cost and the time returning to normal life of day-surgery group were superior to that of the hospitalized group. Conclusion · 1470 nm laser with foam sclerotherapy with ligation of great saphenous vein and 808 nm laser with foam sclerotherapy to treat varicose veins of lower extremity had similar clinical effect, but the degree of safety and comfort was higher and trauma was less. The day surgery with 1470 nm laser to treat varicose vein of lower extremity could also simplify the procedure of hospitalization and reduce the cost of health care, which could be a new option for patients.

Objective To investigate the effect of ketamine on hippocampal uncoupling protein 2 (UCP 2) expression after forebrain ischemia-reperfusion (I/R) in rats and the mechanism of protective effect of ketamine on brain. Method Forty-five male Wistar rats weighing 250～300 g were randomly divided into 3 groups, with 15 animals in each group. Forebrain I/R was estabhshed by occlusion of bilaleral carotid artery combined with hy-potemion,EFG in a sustained low rate of 7 Hz, 30～40 μVθ rhythm was the success signs of forebrain I/R. Con-trol group (C) :sham operation was performed; I/R group (Ⅰ): bilateral common carotid arteries were clamped for lOmin combined with hypotension [MAP:(40±5) mmHg] induced by exsanguinations, then saline (1 mg/kg) was injected into the lateral cerebral ventricle using microsyringe; ketamine group (K):ketamine (1 mg/kg) was injected into the lateral cerebral ventricle using microsyringe after I/R. The animals were decapitated, the brain was immediately removed,and the hippocampal tissues were dissociated at 6 h after reperfusion. The cerebral I/R injury was observed with light microscope, the levels of UCP 2 mRNA expression in hippocampus were detected by using semi-quantitative RT-PCR technique (n=7), coronal sections including hippocampal tissue were obtained for detection of UCP 2 protein expression by immuno-histochemistry (IH) method (n=8). The RT-PCRR and IH data were expressed as the mean±SD, the statistical signiticance was determined by one-way ANOVA. Results The UCP 2 mRNA expression was (1.06±0.02) in group Ⅰ and (1.18±0.06)in group K increased significantly compared with that in group C(0.91±0.02) (P<0.05), there were more UCP2 mRNA expression in group K increased than that in group Ⅰ(P<0.05). The expression of UCP 2 protein was (31.56±4.01) in group Ⅰ and (44.61±4.96) in group K, increased significantly compared with that in group C (17.91±5.49) (P<0.05),there were more UCP 2 protein expression in group K than that in group Ⅰ (P<0.05). Conclusions Ketamine can attenuate the cerebral I/R injury in rats, the underlying mechanism may be related to the up-regulartion of the expression of hippocampal UCP 2 mRNA and UCP 2 protein.

Occupational Medicine ; education

ObjectiveTo study the protective effects of tert-butylhydroquinone(tBHQ) on sodium arsenite (NaAsO2)-induced cytotoxicity and oxidative injuries. Methods Chang liver cells were pretreated with tBHQ[0(control), 5, 25 μmol/L]for 24 h, and then co-treated with tBHQ(5 μmol/L) together with NaAsO2[0(control),30, 40, 50, 60 μmol/L] for another 24 h, and Alamar blue reduction rates were used to evaluate cell viability,the results were expressed as the relative ratio of Alamar blue reduction rates between the experimental group and the control group. On the other hand, Chang liver cells were pretreated with tBHQ[0(control), 5, 25 μmol/L] for24 h,and then co-treated with tBHQ(5 μmol/L) together with NaAsO2[0(control), 40, 50 μmol/L] for another 24 h,and the levels of cellular reactive oxygen species(ROS) were detected by staining cells with 2',7'-dichlorofluorescin diacetate(DCFH-DA), the results were expressed as the relative ratio of mean fluorescence intensity between the experimental group and the control group. ResultsCell viability decreased dramatically by treatment with NaAsO2(30, 40, 50, 60 μmol/L), while relieved to some extent by pretreatment with 5, 25 μmol/L tBHQ, the main effects of NaAsO2 and tBHQ, as well as their interaction were all statistically significant(F =566.57, 55.09, 14.50,all P ＜ 0.05) ; the cell viability of NaAsO2(30, 40, 50, 60 μmol/L) pretreated with tBHQ(5, 25 mol/L) were 0.75 ±0.02, 0.70 ± 0.04, 0.59 ± 0.03, 0.43 ± 0.03 and 0.75 ± 0.02, 0.73 ± 0.03, 0.65 ± 0.02, 0.50 ± 0.02, respectively,all significantly higher than corresponding NaAsO2 alone groups(0.70 ± 0.03, 0.64 ± 0.03, 0.43 ± 0.03, 0.33 ±0.01, all P ＜ 0.05), the cell viability of NaAsO2(50, 60 μmol/L) pretreated with 25 μmol/L tBHQ was higher than corresponding 5 μmol/L tBHQ pretreatment groups(all P ＜ 0.05). On the other hand, 40, 50 μmol/L of NaAsO2 significantly induced hepatocellular ROS generation, while tBHQ(5, 25 μ mol/L) pretreatment significantly decreased NaAsO2-induced intracellular ROS levels, the main effects of NaAsO2 and tBHQ, as well as their interaction were all statistically significant (F =181.78, 60.55, 4.93, all P ＜ 0.05) ; the ROS levels of NaAsO2(40, 50 μ mol/L) pretreated with tBHQ(5, 25 μmol/L) were 1.87 ± 0.09, 1.80 ± 0.07 and 1.36 ± 0.11, 1.44 ± 0.12,all significantly decreased than corresponding NaAsO2 alone groups(2.30 ± 0.18, 2.18 ± 0.17, all P ＜ 0.05),the ROS levels of NaAsO2(40, 50 μmol/L) pretreated with 25 μmol/L tBHQ decreased than corresponding 5 μmol/L tBHQ pretreatment groups (all P ＜ 0.05). ConclusiontBHQ has a certain antagonism on arsenic induced cytotoxicity and oxidative injuries.

Background Macular hole in high myopia has been paid tremendous attention in clinical research due to its high recurrence rate and unpredictable prognosis.Spectral domain optical coherence tomography (SD-OCT) is considered to be of a good evaluating value for macular hole,yet its application is compromised in patient with high myopia.High myopia might lead to retinal detachment which consequently prevents an accurate OCT.Therefore,it is important to assess the effectiveness of OCT on prognosis in these patients after surgical restoration of the detached retina.Objective The aim of this study was to evaluate the risk of reopening of a macular hole in highly myopic patient after removing silicone oil by SD-OCT.Methods A case-observational study was designed.Twenty-five highly myopic patients with monocular macular holes who underwent vitrectomy combined with internal limiting membrane peeling and silicone oil tamponade were included in this study.Four patients were male and 21 patients were female,with the average age (61.4±9.0) years old and diopter (-14.14 ±6.86)D.Regular ocular examination,axial length measurement,fundus photography and OCT were performed at the day before removing silicone oil and every month till the 6 months after operation.Retinal thickness,macular height index (MHI) and choroidal thickness were measured by OCT.Written informed consent was obtained from each patient.Results All 25 patients finished the follow-up of 6 months.Macular holes remained closure 6 months after operation in 19 patients (76％) and reopened in 6 patients macular holes were in 1-5 months (24％),with a mean time at (3.3± 1.4) months.The average foveal retinal thickness,MHI and the choroidal thickness at the middle of the macular hole were (216.5±95.6) μm,0.30 ± 0.09 and (122.9 ± 20.5) μm in the closed group,respectively,and those in the unclosed group were (113.5±28.7) μm,0.58±0.27 and (96.8±22.9) μm,with significant differences between the two groups (t=2.577,-4.143,2.669,P ＜ 0.05).The percentage of macular hole closure was 85.7％ in the MHI＜0.5 group and 25.0％ in the MHI ≥ 0.5 group,showing a significant difference (P =0.031).The base diameter in the unclosed hole group was significantly larger than that in the closed hole group (1070.2±393.6 μm versus 533.3±277.7 μm) (t =-3.700,P =0.001).Conclusions The measurements of the retinal thickness,MHI and the choroidal thickness at the central area of the macular hole are helpful for the evaluation of reopening risk of macular hole after removing silicone oil.