Associations of daily sedentary behavior,physical activity,and sleep with irritable bowel syndrome:A prospective analysis of 362,193 participants

Background:Irritable bowel syndrome(IBS)substantially affects quality of life and requires early prevention.This study aimed to elucidate the relationships between IBS and daily behaviors,including sedentary behavior(SB),physical activity(PA),and sleep.In particular,it seeks to identify healthy behaviors to reduce IBS risk,which previous studies have rarely addressed.Methods:Daily behaviors were retrieved from self-reported data of 362,193 eligible UK Biobank participants.Incident cases were determined by self-report or health care data according to RomeⅣcriteria.Results:A total of 345,388 participants were IBS-free at baseline,during a median follow-up of 8.45 years,19,885 incident IBS cases were recorded.When examined individually,SB and shorter(≤7 h/day)or longer(>7 h/day)sleep duration were each positively associated with increased IBS risk,and PA was associated with lower IBS risk.The isotemporal substitution model suggested that replacing SB with other activities could provide further protective effects against IBS risk.Among people sleeping≤7 h/day,replacing 1 h of SB with equivalent light PA,vigorous PA,or sleep was associated with 8.1%(95%confidence interval(95%CI):0.901-0.937),5.8%(95%CI:0.896-0.991),and 9.2%(95%CI:0.885-0.932)reduced IBS risk,respectively.For people sleeping>7 h/day,light and vigorous PA were associated with a 4.8%(95%CI:0.926-0.978)and a 12.0%(95%CI:0.815-0.949)lower IBS risk,respectively.These benefits were mostly independent of genetic risk for IBS.Conclusion:SB and unhealthy sleep duration are risk factors for IBS.A promising way to mitigate IBS risk for individuals sleeping≤7 h/day and for those sleeping>7 h/day appears to be by replacing SB with adequate sleep or vigorous PA,respectively,regardless of the genetic predisposition of IBS.

A Problem Not to Be Ignored: The Influencing Factors of Mobile Phone Addiction and Its Influence on Sleep Quality

Background and Objective: With the popularity and widespread use of mobile phones, the effects of mobile phone dependence and addiction on individuals’ physical and mental health have attracted more and more attention. The present study aims to analyze the current state of mobile phone addiction and its impact on sleep quality within the population, while also exploring the influence of related factors on sleep quality. Ultimately, this research will provide a scientific foundation for targeted intervention measures and strategies. Methods: A total of 253 permanent residents in Nanjing were randomly selected as study subjects. The Mobile Phone Addiction Index (MPAI) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the degree of smartphone addiction and sleep quality of the study subjects. Body mass index (BMI) was measured according to standardized procedures. Independent sample t-test, Chi-square test, rank sum test and multiple linear regression were used to analyze the correlation between mobile phone addiction and sleep quality, and P Results: 117 people (46.2%) were addicted to mobile phones. Chi-square test showed that the rate of mobile phone addiction in drinking group was significantly higher than that in non-drinking group (P P P P P P P P P P Conclusion: Mobile phone addiction may lead to shorter sleep duration and reduce sleep efficiency. The withdrawal of mobile phone addiction may have a negative impact on sleep quality. According to the characteristics of the population, appropriate comprehensive intervention measures should be taken to build an effective evaluation system, so as to reduce the impact of mobile phone addiction and withdrawal problems on sleep and improve sleep quality.

Adherence to 24-hour movement guidelines in children with mental,behavioral,and developmental disorders:Data from the 2016-2020 National Survey of Children's Health

Background:Adopting a healthy lifestyle during childhood could improve physical and mental health outcomes in adulthood and reduce relevant disease burdens.However,the lifestyles of children with mental,behavioral,and developmental disorders(MBDDs)remains under-described within the literature of public health field.This study aimed to examine adherence to 24-hour movement guidelines among children with MBDDs compared to population norms and whether these differences are affected by demographic characteristics.Methods:Data were from the 2016-2020 National Survey of Children’s Health—A national,population-based,cross-sectional study.We used the data of 119,406 children aged 6-17 years,which included 38,571 participants with at least 1 MBDD and 80,835 without.Adherence to the 24-hour movement guidelines was measured using parent-reported physical activity,screen time,and sleep duration.Results:Among children with MBDDs,20.3%,37.0%,60.7%,and 77.3%met the physical activity,screen time,sleep,and at least 1 of the 24-hour movement guidelines.These rates were lower than those in children without MBDDs(22.8%,46.2%,66.7%,and 83.4%,respectively;all p<0.001).Children with MBDDs were less likely to meet these guidelines(odds ratio(OR)=1.21,95%confidence interval(95%CI):1.13-1.30;OR=1.37,95%CI:1.29-1.45;OR=1.29,95%CI:1.21-1.37;OR=1.45,95%CI:1.35-1.56)than children without MBDDs.Children with emotional disorders had the highest odds of not meeting these guidelines(OR=1.43,95%CI:1.29-1.57;OR=1.48,95%CI:1.37-1.60;OR=1.49,95%CI:1.39-1.61;OR=1.72,95%CI:1.57-1.88)in comparison to children with other MBDDs.Among children aged12-17 years,the difference in proportion of meeting physical activity and screen time guidelines for children with vs.children without MBDD was larger than that among children aged 6-11 years.Furthermore,the above difference of meeting physical activity guidelines in ethnic minority children was smaller than that in white children.Conclusion:Children with MBDDs were less likely to meet individual or combined 24-hour movement guidelines than children without MBDDs.In educational and clinical settings,the primary focus should be on increasing physical activity and limiting screen time in children aged 12-17 years who have MBDDs;and specifically for white children who have MBDDs,increasing physical activity may help.

Current status and prospect of treatments for recurrent hepatocellular carcinoma

Owing to its heterogeneous and highly aggressive nature,hepatocellular carcinoma(HCC)has a high recurrence rate,which is a non-negligible problem despite the increasing number of available treatment options.Recent clinical trials have attempted to reduce the recurrence and develop innovative treatment options for patients with recurrent HCC.In the event of liver remnant recurrence,the currently available treatment options include repeat hepatectomy,salvage liver transplantation,tumor ablation,transcatheter arterial chemoembolization,stereotactic body radiotherapy,systemic therapies,and combination therapy.In this review,we summarize the strategies to reduce the recurrence of high-risk tumors and aggressive therapies for recurrent HCC.Additionally,we discuss methods to prevent HCC recurrence and prognostic models constructed based on predictors of recurrence to develop an appropriate surveillance program.

Compliance of Physicians with Standard Precautions of Handling Patients with Infectious Respiratory Disease

Background: Standard precautions (SPs) are the minimum infection prevention practices that aim to protect Health care workers (HCWs) including physicians and prevent them from transmitting the infections to their patients. Purpose: To assess the level of compliance of physicians with standard precautions of handling patients with infectious respiratory disease. Method: A cross sectional questionnaire-based study was conducted in two tertiary level hospitals named M Abdur Rahim Medical College and Hospital, Dinajpur, Bangladesh and Rajshahi Medical College and Hospital, Rajshahi, Bangladesh to assess the level of compliance of physicians with standard precautions. Purposive sampling technique was applied as per inclusion criteria and data was collected by face to face interview from 285 physicians. Statistical analysis of the results was done by SPSS and a p value less than 0.05 was considered as significant. Result: The study revealed that maximum physicians (76.5%) handling patients with infectious respiratory disease had a moderate level of compliance with standard precautions. 78.6% of the physicians had moderate level of awareness about standard precautions. Only 20.35% of the physicians had training on infection control. 94.4% of the respondents didn’t know the component of standard precaution and most of the physicians were not aware of the sequence of wearing and removing the different components of PPEs. Conclusion: The study result implies that with increased awareness, the compliance of the physicians with standard precautions increased. The main reasons of non-compliance with standard precautions were found to be lack of resources, lack of regular training and excess workload.

Lifestyle improvement and the reduced risk of cardiovascular disease:the China-PAR project

BACKGROUND The benefits of healthy lifestyles are well recognized. However, the extent to which improving unhealthy lifestyles reduces cardiovascular disease(CVD) risk needs to be discussed. We evaluated the impact of lifestyle improvement on CVD incidence using data from the China-PAR project(Prediction for Atherosclerotic Cardiovascular Disease Risk in China).METHODS A total of 12,588 participants free of CVD were followed up for three visits after the baseline examination. Changes in four lifestyle factors(LFs)(smoking, diet, physical activity, and alcohol consumption) were assessed through questionnaires from the baseline to the first follow-up visit. Cox proportional hazard models were used to estimate hazard ratios(HRs) and corresponding 95% confidence intervals(CIs). The risk advancement periods(RAPs: the age difference between exposed and unexposed participants reaching the same incident CVD risk) and population-attributable risk percentage(PAR%) were also calculated.RESULTS A total of 909 incident CVD cases occurred over a median follow-up of 11.14 years. Compared with maintaining 0-1healthy LFs, maintaining 3–4 healthy LFs was associated with a 40% risk reduction of incident CVD(HR = 0.60, 95% CI: 0.45–0.79)and delayed CVD risk by 6.31 years(RAP:-6.31 [-9.92,-2.70] years). The PAR% of maintaining 3–4 unhealthy LFs was 22.0%compared to maintaining 0-1 unhealthy LFs. Besides, compared with maintaining two healthy LFs, improving healthy LFs from 2to 3–4 was associated with a 23% lower risk of CVD(HR = 0.77, 95% CI: 0.60–0.98).CONCLUSIONS Long-term sustenance of healthy lifestyles or improving unhealthy lifestyles can reduce and delay CVD risk.

Influence of Tea Leaf Particle Size on Catechin Extraction and Green Tea Sensory Acceptance

The intensity of the bitterness of catechins increases with increased concentration, but the taste palatability decreased in green tea extract. The aim of this study was to investigate whether a blend of tea leaf particles of various sizes would result in a good balance between catechin content and appreciable taste. The control is common tea (CT) with 6 - 10 mm long leaves. Blend tea (BT) was prepared by mixing 5 mm and 120 - 130 mm long tea leaves in a ratio of 3:2. The catechin content of hot water extracts was analyzed by HPLC, and the sensory test was conducted with 99 volunteers. In BT, the total catechin content was significantly higher than that in CT. The sensory test results revealed that BT was less bitter and had more preferable color than CT. More catechins were extracted from BT, but it tasted less bitter. Thus, the recalibration of the tea leaf particle size can result in good balance between catechin content and palatability.

Hydrogeological Investigations of Groundwater and Surface Water Interactions in the Berg River Catchment, Western Cape, South Africa

The Berg River Catchment based in the Western Cape Province,South Africa services the greater Cape Town area with water,subsequent to supplying the vast agricultural activities that exist in the middle and the lower reaches.This study thus investigates the hydrogeochemical interactions between surface and groundwater in the Berg River Catchment with the aim of establishing trends and transfer of constituents between the surface and groundwater systems,investigates the role that geology plays in water chemistry as well as identifies the geochemical processes controlling surface and groundwater chemistry in the catchment.This study was carried out using three types of research designs namely i)experimental research design;ii)field research design and meta-analysis research design.Furthermore,the study made use of hydrochemical data ranging from 2003 to 2013 obtained from the National Water Monitoring Database owned and maintained by the Department of Water and Sanitation and data that were sampled in 2016 by authors and analyzed using the ICP-MS Technique Ground Water Chart,Arc-GIS and Geosoft(Oasis Montaj)were further employed to model the data.The results indicated that:i)in the Upper Berg there is not much interaction and transfer of constituents between surface and groundwater;ii)the Middle Berg,however,indicated a degree of interaction with the sharing of constituents between the two water systems and iii)the Lower Berg indicated only NaCl water type also noting that the area situated near the river mouth whereby there is the mixing of river and seawater.

Heat exposure and hospitalizations for chronic kidney disease in China: a nationwide time series study in 261 major Chinese cities

Background:Climate change profoundly shapes the population health at the global scale.However,there was still insufficient and inconsistent evidence for the association between heat exposure and chronic kidney disease(CKD).Methods:In the present study,we studied the association of heat exposure with hospitalizations for cause-specific CKD using a national inpatient database in China during the study period of hot season from 2015 to 2018.Standard time-series regression models and random-effects Meta-analysis were developed to estimate the city-specific and national averaged associations at a 7 lag-day span,respectively.Results:A total of 768,129 hospitalizations for CKD was recorded during the study period.The results showed that higher temperature was associated with elevated risk of hospitalizations for CKD,especially in sub-tropical cities.With a 1℃ increase in daily mean temperature,the cumulative relative risks(RR)over lag 0-7 d were 1.008[95% confidence interval(CI)1.003-1.012]for nationwide.The attributable fraction of CKD hospitalizations due to high temperatures was 5.50%.Stronger associations were observed among younger patients and those with obstructive nephropathy.Our study also found that exposure to heatwaves was associated with added risk of hospitalizations for CKD compared to non-heatwave days(RR=1.116,95%CI 1.069-1.166)above the effect of daily mean temperature.Conclusions:Short-term heat exposure may increase the risk of hospitalization for CKD.Our findings provide insights into the health effects of climate change and suggest the necessity of guided protection strategies against the adverse effects of high temperatures.

Beware of the serious harm of veterinary drug poisoning:a case report

Veterinary drugs are substances(including pharmaceutical feed additives)used to prevent,treat,and diagnose diseases or regulate the physiological functions of animals.Veterinary drug poisoning in humans is relatively rare both in China and the rest of the world.Here,we report a case of death from veterinary drug poisoning from avermectin-closantel.Avermectin-closantel is a broad-spectrum antiparasitic drug,which has high efficacy against a variety of trematodes and nematodes.

Clinical implications of fatty pancreas:Correlations between fatty pancreas and metabolic syndrome

AIM:To investigate the clinical implications of lipid deposition in the pancreas(fatty pancreas). METHODS:The subjects of this study were 293 patients who had undergone abdominal computed tomography(CT)and sonography.Fatty pancreas was diagnosed by sonographic findings and subdivided into mild,moderate,and severe fatty pancreas groups comparing to the retroperitoneal fat echogenicity. RESULTS:Fatty pancreas was associated with higher levels for visceral fat,waist circumference,aspartate aminotransferase(AST),alanine aminotransferase (ALT),total cholesterol,triglyceride,high density lipoprotein,free fatty acid,γ-GTP,insulin,and the homeostasis model assessment of insulin resistance (HOMA-IR)than the control group(P<0.05).HOMAIR,visceral fat,triglyceride,and ALT also tended to increase with the degree of fat deposition in the pancreas on sonography.In a multivariate logistic regression analysis,HOMA-IR,visceral fat,and ALT level were independently related to fatty pancreas after adjustment for age,body mass index,and lipid profile.The incidence of metabolic syndrome in the fatty pancreas group was significantly higher than in the control group,and the numbers of metabolic syndrome parameters were significantly higher in the fatty pancreas group(P<0.05).CONCLUSION:Sonographic fatty pancrease showed higher insulin resistance,visceral fat area,triglyceride, and ALT levels than normal pancreases.Fatty pancreas also showed a strong correlation with metabolic syndrome.

Effects of Selenium and Zinc on Renal Oxidative Stress and Apoptosis Induced by Fluoride in Rats

Objective To study the effects of selenium and zinc on oxidative stress, apoptosis, and cell cycle changes in rat renal cells induced by fluoride. Methods Wistar rats were given distilled water containing sodium fluoride （50 mg/L NaF） and were gavaged with different doses of selenium-zinc preparation for six months. Four groups were used and each group had eight animals （four males and four females）. Group one, sham-handled control; group two, 50 mg/L NaF; group three, 50 mg/L NaF with a low dose of selenium-zinc preparation （0.1 mg/kg Na2 SeO3 and 14.8 mg/kg ZnSO4 · 7H2O）; and group four, 50 mg/L NaF with a high dose of selenium-zinc preparation （0.2 mg/kg Na2 SeO3 and29.6 mg/kg ZnSO4 · 7H20）. The activities of serum glutathione peroxidase （GSH-Px）, kidney superoxide dismutase （SOD）, and the levels of malondialdehyde （MDA） and glutathione （GSH） in the kidney were measured to assess the oxidative stress. Kidney cell apoptosis and cell cycle were detected by flow cytometry. Results NaF at the dose of 50 mg/L increased excretion of fluoride in urine, promoted activity of urine γ -glutarnyl transpeptidase （ γ -GT）, inhibited activity of serum GSH-PX and kidney SOD, reduce kidney GSH content, and increased kidney MDA. NaF at the dose of 50 mg/L also induced rat renal apoptosls, reduced the cell number of G2/M phase in cell cycle, and decreased DNA relative content significantly. Selenium and zinc inhibited effects of NaF on oxidative stress and apoptosis, promoted the cell number of G2/M phase in cell cycle, but failed to increase relative DNA content significantly. Conclusion Sodium fluoride administered at the dose of 50 mg/L for six months induced oxidative stress and apoptosis, and changes the cell cycle in rat renal cells. Selenium and zinc antagonize oxidative stress, apoptosis, and cell cycle changes induced by excess fluoride.

Relationship between Ambient Fine Particles and Ventricular Repolarization Changes and Heart Rate Variability of Elderly People with Heart Disease in Beijing, China

Objective To explore the effects of particulate matters less than 2.5 μm in aerodynamic diameter （PM2.5） on heart repolarization/depolarization and heart rate variability （HRV）. Methods We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram （ECG） indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PMz.s and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week and meteorology. Results Significant adverse effects of PM2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM2.s on HRV was on lag i day in our study. However, there were no associations between PM2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM2.5 on subjects with hypertension were larger than on the subjects without hypertension. Conclusion This study showed ambient PM2.5could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM2.5.

Inhibitory Effects of Selenium on Telomerase Activity and hTERT Expression in Cadmium-transformed 16HBE Cells

To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells. Methods Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses （0.625, 1.25, 2.50, 5.00 pmol/L） for 24 hours. Results Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of madl mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group. Conclusion Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing madl mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

Differentiation of acute and chronic hepatitis B in IgM antiHBc positive patients

AIM: To identify the factors that differentiate acute hepatitis B(AHB) from chronic hepatitis B with acute exacerbation(CHB-AE).METHODS: From 2004 to 2013, a total of 82 patients(male n = 52, 63.4%; female n = 30, 36.6%) with clinical features of acute hepatitis with immunoglobulin M antibodies to the hepatitis B core antigen(Ig M antiHBc) were retrospectively enrolled and divided into two groups; AHB(n = 53) and CHB-AE(n = 29). The AHB group was defined as patients without a history of hepatitis B virus(HBV) infection before the episode and with loss of hepatitis B surface antigen within 6 mo after onset of acute hepatitis. Biochemical and virological profiles and the sample/cutoff(S/CO) ratio of Ig M anti-HBc were compared to determine the differential diagnostic factors.RESULTS: The multivariate analysis demonstrated that, the S/CO ratio of Ig M anti-HBc and HBV DNA levels were meaningful factors. The S/CO ratio of Ig M anti-HBc was significantly higher in the AHB group, while the HBV DNA level was significantly higher in the CHB-AE group. The optimal cutoff values of Ig M anti-HBc and HBV DNA levels for differentiating the two conditions were 8 S/CO ratio and 5.5 log10 IU/m L, respectively. The sensitivity and specificity were 96.2% and 89.7% for the S/CO ratio of Ig M anti-HBc and 81.1% and 72.4% for HBV DNA levels, respectively. The area under receiver operating characteristic curves of both the S/CO ratio of Ig M anti-HBc and HBV DNA levels were not significantly different(0.933 vs 0.844, P = 0.105). When combining Ig M anti-HBc and HBV DNA, the diagnostic power significantly improved compared to HBV DNA alone(P = 0.0056). The combination of these factors yielded a sensitivity and specificity of 98.1% and 86.2%, respectively.CONCLUSION: The combination of the S/CO ratio of Ig M anti-HBc and HBV DNA levels was a useful tool for differentiating AHB from CHB-AE in patients with positive Ig M anti-HBc.

Maternal and Fetal Exposure to Four Carcinogenic Environmental Metals

Objective To examine maternal and fetal exposure levels to four carcinogenic metals, arsenic （As）, cadmium （Cd）, nickel （Ni）, and beryllium （Be）, and to investigate their environmental influences. Methods Metal concentrations in maternal and umbilical cord blood were measured by inductively coupled plasma-mass spectrometry （ICP-MS）. Environmental factors that might play a role in exposure were analyzed using Mann Whitney nonparametric U-tests and multiple linear regression. Results The concentrations of As, Cd, and Ni in umbilical cord blood （5.41, 0.87, and 139.54 gg/L） were significantly lower than those in maternal blood （6.91, 1.93, and 165.93 p.g/L）. There were significant positive correlations between the maternal and cord concentrations of each carcinogen. Our results showed that： （i） exposures to potentially harmful occupational factors during pregnancy were associated with high levels of maternal As, Cd, and Ni; （ii） living close to major transportation routes （〈500 m） or exposure to second-hand smoke during pregnancy increased the maternal Cd levels and （iii） living close to industrial chimneys induced high maternal Ni levels. Multiple linear regression analysis showed that these environmental factors remained significant in models of the influences of these four carcinogens. Conclusion Both mothers and fetuses had been exposed to As, Cd, Ni, and Be. The increased levels of these carcinogens in pregnant women were associated with some detrimental environmental factors, such as occupational exposure, contact with second-hand smoke and living close to major transportation routes or industrial chimneys.

Effects of Low Concentrations of Di-(2-ethylhexyl) and Mono-(2-ethylhexyl) Phthalate on Steroidogenesis Pathways and Apoptosis in the Murine Leydig Tumor Cell Line MLTC-1

The aim of this study was to evaluate the effects of low concentrations of DEHP and MEHP on steroidogenesis in a murine Leydig tumor cell line （MLTC-1） in vitro. The result of flow cytometry analysis revealed that the proportion of apoptotic cells was significantly increased after the exposure to DEHP. All three genes （P450scc, P450c17, and 38HSD） under study showed an increased expression following exposure to DEHP or MEHP, although some insignificant inhibitory effects appeared in the 10μmol/L treatment group as compared with the controls. It was also found that DEHP or MEHP stimulated INSL3 mRNA and protein especially in the 0.001 μmol/L treatment group. Testosterone secretions were stimulated after the exposure to DEHP or MEHP. Alterations of steroidogenic enzymes and INSL3 in MLTC-1 cells might be involved in the biphasic effects of DEHP/MEHP on androgen production.

Risk Factors of Low Back Pain among the Chinese Occupational Population:A Case-control Study

Objective To explore the risk factors of low back pain among the Chinese occupational population in several major industries. Methods A total of 7200 subjects （3600 cases and 3600 controls） were randomly sampled from a cross-sectional study, and they were investigated for individual and occupational factors of low back pain. The potential risk factors were first selected by using chi-square tests. Secondly, collinearity diagnosis proceeded by using the Kendall＇s rank correlation. Finally, binary logistic regression model was used for multi-factor analysis. Results Collinearity diagnosis showed that there was a severe collinearity problem among the potential risk factors of low back pain. Logistic regression model included 20 variables with statistical significance. Bending neck forward or holding neck in a forward posturefor long periods （0R=1.408） was the most important risk factor inducing low back pain in this study, followed by bending heavily with the trunk （0R=1.402）, carrying out identical work almost for the whole day （0R=1.340）. Additionally, suHicient normal break was a protective factor of low back pain. Conclusion Low back pain among the Chinese occupational population was associated with body height, occupation, work organization, physical work, working posture, and others. All these risk factors could be regarded as the indicators of low back pain, and some relevant preventive measures should be taken to reduce low back pain risk.

Effects of Cadmium on Hepatocellular DNA Damage,Proto-Oncogene Expression and Apoptosis in Rats

Objective To study the effects of cadmium on hepatocellular DNA damage, expression of proto-oncogenes c-myc, c-fos, and c-jun as well as apoptosis in rats. Methods Cadmium chloride at the doses of 5, 10, and 20 μmol/kg was given to rats by i.p. and there were 5 male SD rats in each group. Hepatocellular DNA damage was measured by single cell gel electrophoresis （or comet assay）, while expression of proto-oncogenes c-myc, c-fos, and c-jun in rat hepatocytes were measured by Northern dot hybridization. C-Myc, c-Fos, and c-Jun were detected with immuno-histochemical method. Hepatocellular apoptosis was determined by TUNEL （TdT-mediated dUTP Nick End Labelling） and flow cytometry. Results At the doses of 5, 10, and 20 μmol/kg, cadmium chloride induced DNA damage in rat hepatocytes and the rates of comet cells were 50.20%, 88.40%, and 93.80%, respectively. Results also showed an obvious dose-response relationship between the rates of comet cells and the dose of cadmium chloride （r=0.9172, P〈0.01）. Cadmium chloride at the doses of 5, 10, and 20 μmol/kg induced expression of proto-oncogenes c-myc, c-fos, and c-jun. The positive brown-yellow signal for c-myc, c-fos, and c-jun was mainly located in the cytoplasm of hepatocytes with immunohistochemical method. TUNEL-positive cells were detected in cadmium-treated rat livers. Apoptotic rates （%） of cadmium-treated liver cells at the doses of 5, 10, and 20 μmol/kg were （17.24 ±2.98）, （20.58± 1.35）, and （24.06±1.77） respectively, being significantly higher than those in the control. The results also displayed an obvious dose-response relationship between apoptotic rates and the dose of cadmium chloride （r=0.8619, P〈0.05）. Conclusion Cadmium at 5-20 μmol/kg can induce hepatocellular DNA damage, expression of proto-oncogenes c-myc, c-fos, and c-jun as well as apoptosis in rats.

Effects of Cadmium on Telomerase Activity,Expressions of TERT,C-myc and P53,and Apoptosis of Rat Hepatocytes

This study investigated the effect of cadmium on the telomerase activity,the expression of TERT,c-myc and p53 and the apoptosis of rat hepatocytes.The rats were administrated 5,10 and 20 μmol/kg cadmium chloride intraperitoneally and sacrificed 48 h after the initial treatment.The telomerase activity of the rat hepatocytes was measured by the telomeric repeat amplification protocol (TRAP),and apoptosis was detected by flow cytometry.The mRNA expressions of TERT,c-myc and p53 were measured by reverse transcription-polymerase chain reaction (RT-PCR).C-myc and P53 proteins were determined by immunochemistry.The results showed that cadmium chloride increased the hepatocellular telomerase activity in a dose-dependant manner and induced the apoptosis of hepatocytes significantly.The value of relative coefficient between the telomerase activity and the apoptosis rate was 0.9398.RT-PCR revealed that specific bands corresponding to the TERT mRNA,c-myc mRNA,and p53 mRNA were displayed at 185,342 and 538 bp respectively.Cadmium chloride could substantially increase the mRNA expressions of TERT,c-myc and p53 in rat hepatocytes,as compared with control.Moreover,cadmium chloride at the doses of 5,10 and 20 μmol/kg could increase the content of P53 protein in rat hepatocytes obviously,but only that at the doses of 10 and 20 μmol/kg substantially promoted the c-myc protein level in rat hepatocytes.Our study herein suggested that cadmium may contribute to the carcinogenesis by activating telomerase,and overexpressing the mRNAs of TERT,c-myc and p53,and causing apoptosis of normal cells.