Objective To investigate the associations of atrial natriuretic peptide(ANP)rs5065 and brain natriuretic peptide(BNP)rs198389 gene polymorphisms with human essential hypertension(EH).Methods A total of 976 patients with EH and 976 age-and sex-frequency matched normotensive(NT)control subjects were collected.The ANP rs5065 and BNP rs198389 polymorphisms were genotyped by real-time quantitative polymerase chain reaction(real-time Q-PCR)method--Taqman probe.Results There was significant difference in frequency distribution of AA and AG+GG genotypes,A and G allele of BNP rs198389 between the EH and NT groups(P＜0.05).The frequency of AG+GG genotype and G allele was significantly higher in the EH group(30.5% and 17.3%)than in the NT group(26.1% and 14.1%).There was no difference in distribution of ANP rs5065 polymorphism between EH and NT groups(P＞0.05).By unconditional Logistic regression analysis of rs198389,before adjusted for the EH risk factors,AG+GG genotype presented a significantly higher risk of EH(P=0.04)than AA genotype,and this risk was still significant after adjusted for the EH risk factors(P=0.02).G allele had more significantly increased risk of EH than A allele(P=0.04).However,there was no significant difference before or after adjusted for the EH risk factors in unconditional Logistic regression analysis of rs198389.Conclusion rs198389 polymorphisms of BNP gene may be associated with EH,but rs5065 polymorphisms of ANP gene may be not associated with EH.

Objective To investigate the mechanism of ventricular dilation-induced arrhythmias by dilating isolated rat hearts. Methods Isolated rat hearts were perfused by Langerdorff method. After equilibration, 80 hearts were randomly divided into four groups as follows: (1) control group (n=20), (2) Ca2+ preconditioning (CPC) group (n=20), (3) streptomycin group (n=20), and (4) CPC + streptomycin group (n=20). A latex balloon which can be filled with fluid was anchored in the left ventricle through the left atrium and mitral valve. Epicardial ECG of the left ventricle, left ventricular pressure, coronary flow and heart rate were recorded before and during ventricular dilation by injecting fluid into the latex balloon. The rate and duration of ventricular dilation-induced arrhythmias were recorded. Results Under the same increase in ventricular end-diastolic pressure made by inflation of the balloon, the rate of arrhythmias was 100% and duration of arrhythmias was 2.56±0.46 s in the control group. Both the rates of premature ventricular beat (90 %) and ventricular tachycardia 70 % ) were high. Compared with the control group, the total rate (60 % ) of arrhythmias was lower, and duration (1.67±0.61 s ) of arrhythmias was shorter in the CPC group. Both the rates of premature ventricular beat (60%) and ventricular tachycardia (40%) were low comparatively. The rate of arrhythmias (45 %) was lower and duration ( 1.64±0.42 s)of arrhythmias was shorter, and the rates of premature ventricular beat (30 % ) or ventricular tachycardia (35 %) were lower in the streptomycin group than in the control one. The least ventricular dilation-induced arrhythmias occurred in the CPC + streptomycin group. The rate of arrhythmias (10%) was the lowest and duration (1.01±0.37s) of arrhythmias was the shortest; both the rates of premature ventricular beat (5%) and ventricular tachycardia (10%) were the lowest. Conclusions Ventricular dilation may induce arrhythmias in isolated rat hearts. Stretch-activated ion channel and the increase in [Ca2+]I are supposed to play important roles in the pathological mechanism.

The association between atrial natriuretic peptide (ANP) polymorphism and coronary heart disease (CHD) was studied in Chinese population. The genotypes of ANP T2238C and ANP C-664G were detected by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) methods in 158 consecutive CHD patients and 165 controls. It was found that the distribution of A2A2 genotype in CHD group was significantly higher than that in control group (P<0.05). Stepwise Logistic regression analysis revealed that male, smoking, history of hypertension, history of diabetes, family history of hypertension, high level of serum cholesterol, and ANP T2238C polymorphism were the possible risk factors in patients with CHD (P<0.05). However, there was no significant difference between the patients with CHD and the control group in the distribution of ANP C-664G polymorphism (P>0.05). The results suggest that A2A2 T2238C genotype could be one of the risk factors for CHD (P<0.05, OR: 1.80, 95 % CI: 1.03-3.15).

The relation between the expression and activity of MMP-9 in C-reactive protein (CRP)-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B (NF-kappaB) was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 (control group), 25, 50 and 100 mug/mL (CRP groups) for 24 h. In PDTC (a specific NF-kappaB inhibitor) group, the cells were pre-treated with PDTC at 10 mumol/L and then with 100 mug/mL CRP. The conditioned media (CM) and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-kappaB inhibitor alpha (IkappaB-alpha) and NF-kappaB P(65) was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IkappaB-alpha expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-kappaB P65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 mumol/L, the decrease in IkappaB-alpha expression and the increase in NF-kappaB P(65) expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-kappaB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-kappaB activation.

To explore the role of mechanosensitive potassium channel TREK-1, Western blot analysis was used to investigate the expression changes of TREK-1 in left ventricle in acute mechanically stretched heart. Forty Wistar rats were randomly divided into 8 groups (n=5 in each group), subject to single Langendorff perfusion for 0, 30, 60, 120 min and acute mechanical stretch for 0, 30, 60, 120 min respectively. With Langendorff apparatus, an acute mechanically stretched heart model was established. There was no significant difference in the expression of TREK-1 among single Langendorff perfusion groups (P>0.05). As compared to non-stretched Langendorff-perfused heart, only the expression of TREK-1 in acute mechanically stretched heart (120 min) was greatly increased (P<0.05). This result suggested that some course of mechanical stretch could up-regulate the expression of TREK-1 in left ventricle. TREK-1 might play an important role in mechanoelectric feedback, so it could reduce the occurrence of arrhythmia that was induced by extra mechanical stretch.
Feedback ; Heart Ventricles/*metabolism ; Mechanotransduction, Cellular ; Potassium Channels, Tandem Pore Domain/*metabolism ; Random Allocation ; Rats, Wistar ; Stress, Mechanical

Associations between "lipid-related" candidate genes, blood lipid concentrations and coronary artery disease (CHD) risk are not clear. We aimed to investigate the effect of three newly identified lipids loci from genome-wide association studies on CHD and blood lipid levels in Chinese Han population. The genotypes of SNPs at three newly identified lipid loci and blood lipids concentrations were examined in 1360 CHD patients and 1360 age- and sex-frequency matched controls from an unrelated Chinese Han population. Allele T of rs16996148 occurred less frequently in CHD patients with the odds ratio (OR) being 0.64 (95% CI 0.50 to 0.81), after adjusting for conventional risk factors and was associated with a 33% decreased CHD risk (P<0.01) comparing with the major allele G. Individuals with GT genotype had the lowest CHD risk. No associations were found between the polymorphisms of other two loci with CHD risk and all three SNPs had no effect on lipid profile in this population. SNP rs16996148 on chromosome 19p13 is significantly associated with lower risk for CHD in Chinese Han population. However, it remains unresolved why these lipid-related loci had significantly less effects than the correspondingly expected effects on blood lipids levels in this population.

Objective To investigate the rs501120 and rs17465637 gene polymorphisms,and their relationship with the risk of coronary heart disease(CHD)in Chinese Han population.Methods 775 CHD without treatment and 775 age and gender matched controls were selected for this study,the genotypes of two single nucleotide polymorphisms(SNP)rs501120 and rs17465637 were tested with TaqMan-MGB probes.Results There was no significant difference in the frequency of genotypes of the 2 SNPs between CHD group and control group(P ＞0.05).Stratified analysis showed that SNP rs501120 had significant protection with CHD in people younger than 60 years old(OR 0.4,95% CI 0.2-0.9,P ＜ 0.05)or people with diabetes(OR0.3,95%CI0.1-0.7,P ＜0.05).Conclusions The results suggested that rs501120 was tightly associated with CHD in people younger than 60 years or had diabetes.

To understand the Escherichia coli (E .coli) O157∶ H7 isolated from cow in Zhengzhou ,Henan Province ,a total of 146 samples of cow fecal and milk were collected in the different farms ,and E .coli O157∶ H7 was detected with mul-tiplex polymerase chain reaction (PCR) in our laboratory .Then the biochemical characteristics ,growth dynamic ,the biofilm formation ,and the toxin genes of the E .coli O157∶ H7 isolates were analyzed .The results showed that 2 strains of E .coli O157∶H7 were found ,with the detection rate of 1 .4% ,and the isolates were named as L1 and L2 in current study ,respec-tively .The E .coli O157∶H7 clinical isolates had the same biochemical characteristics with that of the typical E .coli .The L1 and L2 isolates presented similar growth curve ,which entered into the log phase earlier than that of the standard strain .L1 strain formed thick ,confluent ,complete biofilm after 48 hours post-inoculation ,and the biofilm of L2 strain was formed com-pletely in 36 hours .The two E .coli O157∶ H7 isolates were positive with eaeA and hlyA genes ,and the L1 strain also carried the Stx2 virulence gene .Our results reinforce the epidemiological data of E .coli O157∶H7 ,and underscore the need for more effective surveillance of animal-derived E .coli O157∶H7 isolates in Zhengzhou City ,China .

AIM: To investigate the effects of mechanical stretch under simulated anoxia and reoxygenation conditions on action potential (AP) and effective refractory period (ERP) of calcium preconditioning (CPC) in isolated papillary muscles of guinea pig hearts. METHODS: The intracellular standard glass microelectrode technique was used, and effects of stretch (intensity: 200 mg) on AP and ERP were recorded and observed in CPC papillary muscles. RESULTS: After stretching was implied during anoxia, the reductions of Vmax, RP, APA, APD_(50), ERP and APD_(90) in CPC group were less than those in anoxia-reoxygenation (AR) group, and the CT in CPC group was less elongated. Moreover, after the papillary muscles were stretched during reoxygenated reperfusion, the decreases in Vmax, RP, APA, APD_(50) and ERP in CPC group were less than those in AR group, and the CT and APD_(90) in CPC group were less extended. Streptomycin inhibited the effect of stretch on AP and ERP in CPC group. CONCLUSIONS: Under simulated anoxia and reoxygenation conditions, papillary muscles in CPC group may have better tolerance to the same stretch than those in the AR. Furthermore, streptomycin (a blockade of stretch-activated ionic channels) may inhibit the effect of mechanical stretch on action potential changes in CPC papillary muscles.

Objective To observe the relationship of right internal jugular vein (RIJV)and common carotid artery (CAA)by scanning strictly from the anterior to posterior using ultrasound at different head rotation.Methods Using ultrasonic scanning,the anatomic features of RIJV and CAA both at thyroid cartilage level (prominentia laryngea level)and at the apex of the angle formed by the division of the sternocleidomastoid muscle (triangle level)with 0°,1 5°,30° and 45° right rotation were observed in 131 patients with ASA physical status Ⅰ or Ⅱ (male 55 cases,female 76 cases, aged 18~74 years).Based on the ultrasound images,the safe puncture range,the overlapping ratio, the angle between the horizontal axis and the line from the midpoint of RIJV to that of CAA (αangle) were measured.In addition,the relationship between the RIJV and CAA was defined as anterior-lat-eral, lateral, posterior-lateral or extremely-posterior-lateral position according to α angle. Results The safe puncture range of RIJV augmented as head rotated from 0° to 30° position(P <0.05);The safe puncture range of RIJV at triangle level was significantly higher than at prominentia laryngea level at all the four head positions(P <0.05).The overlapping degree decreased as head rota-ted from 0°to 30°head position at prominentia laryngea level(P <0.05).No siginificant differences of the overlapping degree were found between head positons at triangle level;The overlapping degree at triangle level was less than at prominentia laryngea level when at 0°and 1 5°head positon(P <0.05). At both prominentia laryngea and triangle levels,RIJV located mainly at lateral and posterior-lateral positions.In addition,the part of lateral position increased while the part of posterior-lateral position decreased as the head rotated from 0°to 45°position(P <0.05).Conclusion The puncture conditions for RIJV catheterization were more optimal at 30°to 45°head rotation for a safer puncture range and less overlapping between RIJV and CAA.RIJV located mainly at lateral and posterior-lateral positions at different rotations and RIJV gradually shifted to lateral position while head rotation increasing.It would be much better to select triangle level for central venous catheterization than prominentia laryn-gea level.