Objective: To explore the rule of voltage change in the reference point of electrocardiograms ( ECG). Methods: The r and R′ waves on the head-chest lead and routine lead ECGs in 21 patients with right bundle branch block in whole synchronization were compared, and the correlation of voltage change in reference point with the direction of cardiac muscular stimulation of ECGs was analyzed. Results: The swing of wave r in head-chest leads was significantly higher than that of routine leads([0.16±0.19] vs [0.11±0.13] mV, P<0.01), and the swing of wave R′ in head-chest leads was significantly lower than that of the routine leads( [0.25±0.21] vs [0.35±0.23] mV, P<0.01). Conclusion: Voltage change in reference point of ECG varies with the direction of cardiac muscular stimulation.

Objective: To study the changes and rules of the reference point potentials of electrocardiograms (ECGs) before and after pacing. Methods: The head-chest lead and routine lead ECGs of the patients with permanent pacemaker implantation were recorded with and without right ventricular pacing; the Q, R and S wave amplitudes were compared between the 2 ECGs. Results: Without right ventricular pacing, the amplitudes of Q and S wave of routine lead were higher than those of the headchest lead; the amplitude of R wave was lower than that of the head-chest lead. With right ventricle pacing, the amplitudes of Q, R, and S waves of routine lead were lower than those of head-chest lead (all P<0.01). Conclusion: The transduction direction of the cardiac excitement has great influence on the potentials of the reference point.

Objective To study the influence of arsenic exposure on menstruation.Methods A cluster sampling method was applied to select the subjects of women aged 10 to 65 from Linhe,Hangjinhouqi and Wuyuan counties in Inner Mongolia in 2004.Drinking water samples were collected to detect arsenic levels,and menstrual related situation was surveyed.The subjects were divided into four groups according to drinking water arsenic concentration:control(≤0.01 mg/L),low(＞ 0.01-0.10 mg/L),moderate(＞ 0.10-0.20 mg/L) and high(＞ 0.20mag/L).Results A total of 602 women were surveyed.There were 83 subjects exposed to arsenic before menarche and their menarche age was (14.37 ± 1.54) years old.There were 90 people exposed to arsenic before menopause and the menopause age was (48.13-0.41) years old.The age of menarche and menopause were positively related to the years of arsenic exposure,and correlation coefficients were 0.268 and 0.278 (all P ＜ 0.05).Compared to control group(14.0％,16/112),menstrual abnormality rate decreased in low(12.1％,21/173) and high dose groups(10.2％,19/186),while increased in the moderate dose group(18.2％,16/88),but the differences were not statistically significant(x2 =3.664,P ＞ 0.05).Conclusions Long-term arsenic exposure delays the menarche and menopause age,suggesting that arsenic has certain endocrine disruption or estrogen-like effects.

Hepatitis B virus (HBV) is a major cause of chronic liver disease, and frequently results in hepatitis, cirrhosis, and ultimately hepatocellular carcinoma. HBV polymerase (Pol) is an essential viral protein that is important for HBV replication and might be involved in the development of hepatocellular carcinoma. Protein-protein interactions appears to be crucial for its role. The aim of this study was to screen and identify the proteins that interact with Pol using a co-immunoprecipitation-based LC-MS/MS identification technique. The HBV Pol gene was amplified by polymerase chain reaction (PCR) and cloned into pCDNA3.1(+). The recombinant plasmid pCDNA3. 1(+)-Pol-flag was transfected into HeLa cells. Liquid chromatography and tandem mass spectrometry (LC-MS/MS) identified 45 proteins that co-immunoprecipitated with flag-tagged HBV Pol. Eleven of these have previously been reported as proteins that interact with HBV Pol. A proof-of-concept-based Ingenuity Pathway Analysis (IPA, www.ingenuity.com) was used to characterize the functions and pathways of these 45 identified proteins and HBV Pol. Among these proteins, four proteins may play a role in three major molecular cellular networks, and are therefore worthy of further investigation.
Cell Line, Tumor ; Chromatography, Liquid ; methods ; Gene Products, pol ; chemistry ; genetics ; metabolism ; Hepatitis B ; genetics ; metabolism ; virology ; Hepatitis B virus ; chemistry ; enzymology ; genetics ; Humans ; Immunoprecipitation ; methods ; Protein Interaction Maps ; Software ; Tandem Mass Spectrometry ; methods

AIM: To investigate the roles of nitric oxide/L-arginine(NO/L-Arg) pathway and urotensin-Ⅱ(UⅡ) in the development of pulmonary hypertension induced by chronic hypoxia-hypercapnia in rats.METHODS: Forty male Sprague-Dawley rats were randomly divided into four groups(n=10): normal control group(A),hypoxia-hypercapnia+saline group(B),hypoxia-hypercapnia+L-Arg liposome group(C) and hypoxia-hypercapnia+N-nitro-L-arginine methyl ester(L-NAME) group(D).Contents of UⅡ,UⅡ mRNA and receptor of UⅡ(UT) mRNA in pulmonary arterioles were measured with immunohistochemistry analysis and in situ hybridization,respectively.Change of small pulmonary vascular microstructure was also investigated.RESULTS:(1) The mean pulmonary artery pressure(mPAP) and the weight ratio of right ventricle to left ventricle plus septum [RV/(LV+S)] in B and D groups were all higher than those in A group(respectively,P

Objective To evaluate efficacy and safety of fixed combination of nitrendipine and atenolol in treatment for patients with mild to moderate essential hypertension and their optimal dosage matching.Methods Totally,275 patients with essential hypertension were selcted from seven hospitals in Shanghai,Nanjing and Suzhou,China and randomized into five groups with same proportional probability in a double-blind,double-dummy,parallel active-controlled,multi-center clinical trial,receiving fixed combination of nitrendipine and atenolol at three different dosage matching (nitrendipine/atenolol 5/12.5 mg,5/10 mg,5/7.5 mg for groups 1,2 and 3),and nitrendipine (10 mg for group 4) or atenolol (25 mg for group 5),respectively for eight weeks.Results Mean reduction of diastolic blood pressure (DBP)was (17±7) mm Hg,(18±9) mm Hg and (17±7) mm Hg for groupl,2 and 3,respectively from the baseline,significantly greater than that in groups 4 and 5[(13±7) mm Hg and (12±6) mm Hg,respectively].Mean reduction of systolic blood pressure (SBP) was (21 ±11)mm Hg,(24±12) mm Hg,(23±11) mm Hg,(19±13) mm Hg and (18±9) mm Hg,respectively for the five groups from the baseline,and the reduction in group 2 was significantly greater than that in group 5,with an overall efficacy of 94.4%,98.1% and 88.2% for groups 1,2 and 3,respectively,all statistically higher than that in group 5 (71.4%) with P＜0.01,eight weeks after treatment.The ratio of patients with increased dose of antihypertensive agents in week 5 was lower in group 2 than that in the other four groups,with mild adverse reaction only,no obvious change in laboratory biochemical examinations,and no needs in special management.Conclusions Fixed combination of atenolol and nitrendipine with an optimal doses of 5 mg and 10 mg respepctively was effective and safe for mild and moderate hypertension with good tolerance.

BackgroundReactive oxygen intermediate products lead to the oxidative injury of cells.Retinal pigment epithelial(RPE) cells produce lots of reactive oxygen intermediate products during the swallow of out disc,but how this procedure cause the persistent oxidative injury of RPE cells is poorly understood.Objective The present study was to evaluate the effect of non-lethal H2 O2 -induced persistent oxidative injury on RPE barrier in vitro.MethodsARPE-19 cell links were inoculated on 96 well plate at the density of 8×104 cells/L and the cell climbing slice of 24 well at the density of 4× 104 cells/L.The cells were cultured in DMEM/F12 medium,and the cells cultured for 24 hours in free-serum medium were used in the experiment.0-0.6 mmol/L of H2O2 were added into the medium.Cellular viability was assessed using 3- ( 4,5-dimethylthiazol-2-yl ) -5- ( 3-carboxymethoxyphenyl ) -2- ( 4-sulfophenyl ) 2H-tetrazolium(MTS) assays.Transepithelial electrical resistance (TER) was used to detect cell monolayer forming time after cultureinTrsnswellchamber.Thepermeabilityof cellmonolayer was examinedbyrhodamine isothiocyanate-dextran transepithelial flux,and immunofluorescence was used to investigate the distribution of the junction protein zonula occludens (ZO-1).ResultsThe total difference was found in the cell vitality(A490) among the different concentrations of H2 O2 ( F =991.501,P =0.000 ).Compared with 0 mmoL/L H2 O2 group,the A490 values was gradually lowed from 0.20 mmol/L H2O2 group to 0.60 mmol/L H2O2 group (P ＜ 0.05 ).H2O2 at the concentrations of ＞0.20 mmol/L lowed the viability of RPE cells.The TER value was ( 24.9 ± 1.3 ) Ω · cm2 in 11 days,( 17.8± 1.4)Ω · cm2 in 7 days after inoculation on transwell chamber,showing a significant difference between them (t=5.228,P=0.014).RPE formed the stable tight junction on day 15 with the TER value (25.9±0.9 ) Ω · cm2.The leakage amount ( relative fluorescence intensity ) of the dextran was 255.39 ± 16.44 in non-H2 O2 control group,exhibiting a significant lowing in comparison with free-cell blank group (433.08±51.53)( t =12.515,P =0.006 ),and that of H2 O2 group was significant increased in comparison with non-H2 O2 control group ( t =14.412,P=0.005).Immunofluyorescence assay showed intact intercellular ZO-1 junction in non-H2O2 control group,but the breakage of ZO-1 junction was seen in H2O2 group.ConclusionsThe results indicate that non-lethal H2O2 can destroy RPE barrier and further lead to the persistent oxidative injury of RPE cells.

Objective To study the risk factors of skin lesion (keratosis and abnormal skin pigmentation) of population exposed to arsenic via drinking water in Inner Mongolia.Methods A cluster sampling method was used to select 902 cases from Linhe district,Hanghou and Wuyuan county in Inner Mongolia and physical examination was done.They were interviewed for information by questionnaire.The sample of fingernails and drinking water were collected.Water arsenic (As) was analyzed by inductively coupled plasma mass spectrometry (ICPMS); fingernail As and Se content were analyzed by instrumental neutron activation analysis(INAA).Data were analyzed by univariate and multivariate non-conditional Logistic regression.Results Single factor analysis showed that risk factors of keratosis were age,pesticide,arsenic in nails,smoking,years of smoking,drinking of alcohol,arsenic content in drinking water,fluorosis and duration of drinking arsenic-containing water,while occupation,nail selenium content and vitamin were protective factors.There were 10 risk factors for pigment abnormalities,which were age,pesticide,arsenic in nails,smoking,years of smoking,numbers of cigarette smoked daily,drinking of alcohol,fluorosis,the arsenic content in drinking water and duration of drinking arseniccontaining water,while sex,occupation and nails with selenium were protective factors.The multivariate factor analysis showed that the risk factors of keratosis were age,pesticide and arsenic content in drinking water(OR =1.387,1.583,1.321,all P ＜ 0.05),while occupation and vitamin were protective factors(OR =0.307,0.260,all P ＜ 0.05).The risk factors of abnormal skin pigmentation were age,pesticide,arsenic in nails,fluorosis and arsenic content in drinking water(OR =1.724,2.636,2.741,3.699,1.863,all P ＜ 0.05),while sex was protective factor(OR =0.255,P ＜ 0.01 ).Conclusions Many factors have influence on endemic arsenism and a composite measure should be implemented to prevent it such as excluding arsenic from drinking water,health education,and a reasonably intake of nutrients.

Objective:To investigate the role of extracellular signal-regulated kinase 1/2(ERK1/2)signal pathway in the pathogenesis of stress-induced gastric ulcer.Methods:Animal model of stress-induced gastric ulcer was established in rats with water-immersion restraint(WIR)stress.The mucosal activation of ERK1/2 was observed before and 5,15 and 30 min,and 1, 2 and 3.5 h after WIR stress.Some animals were also treated with an intravenous injection of PD98059(1 mg/kg),a specific ERK1/2 inhibitor,1 h prior to WIR stress.Expression of total ERK1/2 and caspase-3 were detected by Western blot analysis; ERK1/2 activity was measured by kinase activity assay using myelin basic protein as a specific substrate.DNA-binding activities of the transcription factors activator protein-1(AP-1)and nuclear factor-?B(NF-?B)were determined by electrophoretic mobility shift assays(EMSA).Mucosal TNF-?and IL-1?mRNA expression was analyzed by Northern blot analysis.The degrees of the gastric mucosal lesions were expressed as ulcer index(UI)and pathological evaluation.Apoptosis in the gastric mucosa was examined by an in situ TdT-mediated dUTP nick-end labeling(TUNEL)method.Results:Activated ERK1/2 was very weakly expressed in the gastric mucosa of normal rats.ERK1/2 was rapidly activated in the gastric mucosa of rats 15 min after WIR stress and the activity reached the maximal after 3.5 h.Pretreatment with PD98059 significantly inhibited ERK1/2 activation,decreased AP-1 and NF-?B activities and TNF-?and IL-1?mRNA expression,and obviously relieved gastric mucosal lesions,accompanied by caspase-3 activation and increased apoptosis.Conclusion:The present results indicate that ERK1/2 activation plays an important role in the development of stress-induced gastric ulcer.