Comparison of esophageal capsule endoscopy and esophagogastroduodenoscopy for diagnosis of esophageal varices

AIM： To investigate the utility of esophageal capsule endoscopy in the diagnosis and grading of esophageal varices. METHODS： Cirrhotic patients who were undergoing esophagogastroduodenoscopy （EGD） for variceal screening or surveillance underwent capsule endoscopy. Two separate blinded investigators read each capsule endoscopy for the following results： variceal grade, need for treatment with variceal banding or prophylaxis with beta-blocker therapy, degree of portal hypertensive gastropathy, and gastric varices. RESULTS： Fifty patients underwent both capsule and EGD. Forty-eight patients had both procedures on the same day, and 2 patients had capsule endoscopy within 72 h of EGD. The accuracy of capsule endoscopy to decide on the need for prophylaxis was 74%, with sensitivity of 63% and specificity of 82%. Interrater agreement was moderate （kappa = 0.56）. Agreement between EGD and capsule endoscopy on grade of varices was 0.53 （moderate）. Inter-rater reliability was good （kappa = 0.77）. In diagnosis of portal hypertensive gastropathy, accuracy was 57%, with sensitivity of 96% and specificity of 17%. Two patients had gastric varices seen on EGD, one of which was seen on capsule endoscopy. There were no complications from capsule endoscopy.CONCLUSION： We conclude that capsule endoscopy has a limited role in deciding which patients would benefit from EGD with banding or beta-blocker therapy. More data is needed to assess accuracy for staging esophageal varices, PHG, and the detection of gastric varices.

Warm hydroforming of magnesium alloy tube with large expansion ratio

Process of warm tube hydroforming was experimentally investigated for forming an AZ31B magnesium alloy tubular part with a large expansion ratio. Effects of temperature on the mechanical properties and formability were studied by uniaxial tensile test and hydraulic bulge test. Total elongation increases with temperature up to 250℃, but uniform elongation and maximum expansion ratio get the highest value at 175℃. Different axial feeding amounts were applied in experiments to determine the reasonable loading path. A preform with useful wrinkles was then realized and the tubular part with an expansion ratio of 50% was formed. Finally, mechanical condition to produce useful wrinkles is deduced and the result illustrates that useful wrinkles are easier to be obtained for tube with higher strain hardening coefficient value and tubular part with smaller expansion ratio.

THE LONG TERM EFFECT OF CAPTOPRIL TREATMENT ON ENDOTHELIAL FUNCTION IN SPONTANEOUSLY HYPERTENSIVE RATS

The aim of this study is to elucidate the long term effect Of captopril treatment on the endothelial func-tion to release nitric Oxide (NO) in spontaneOusly hypertensive rats (SHR). The properties of endotheliumwere determined with a model of hindquarter perfusion in response to al adrenergic agonist, phenylephrine,at the age of 40 weeks of SHR which was administrated with captopril (100 mg/kg/day) from lntrauterineand withdrawn at 16 weeks of age. Furthermore, in the presence of N-nitro-L-arginine methyl ester(LNAME), or L-arginine, the responses to phenylephrine were studied. From the curve of perfusion pres-sure, the minimal, maximal perfusiOn pressure (PPmin,PPmax) and the maximal slOpe (slope),as well asthe 5O% of effective concentratiOn (EC,,) were obtained. The data show that in captopril treated SHR,PPmin, PPmax and slope were markedly lower, but EC50 higher than those of untreated SHR. The curveinduced by phenylephrine was significantly right shift compared with that of untreated SHR. Like WKY,the intensive reactivity to phenylephrine in the presence of LNAME was much lower than that of untreatedSHR. ln the presence of L-arginine, however, the right shift of curves was seen only in captopril treatedSHR and WKY rats, but not in control SHR. In conclusipn, endothelium does involve in the respnse ofresistant vessel to phenylephrine. The mechanism of enhanced reactivity In untreated SHR may be, at leastin part, due to the diminished capacity of producing No frpm endpthelium, and the effect pf sustained hy-potension of early captopril treatment might be relevant to the improved ability of endOthelium.

深水控压钻井隔水管系统连接作业窗口分析

深水控压钻井(managed pressure drilling,MPD)技术是深水钻井解决钻井液密度窗口较窄问题的重要钻井技术,但目前对于深水MPD隔水管系统连接作业窗口研究较少。基于欧拉-伯努利梁理论,在常规钻井隔水管数学模型的基础上,考虑管内高压及钻井液流速的影响,采用直接刚度矩阵法建立深水MPD隔水管系统理论模型,采用有限元法对理论模型进行离散并采用MATLAB软件开发MPD隔水管数值计算求解器。以南海某1600 m深水井为例,在同样的计算参数下,分别使用本文求解器与ABAQUS软件计算MPD隔水管系统的力学响应,结果表明本文求解器与ABAQUS软件计算结果吻合良好。在此基础上,开展深水MPD隔水管系统连接作业窗口分析,并研究管内高压和钻井液流速对作业窗口的影响。研究结果表明,管内高压对MPD隔水管连接作业窗口影响较大,而钻井液流速对作业窗口影响较小,MPD隔水管连接作业窗口稍大于常规隔水管连接作业窗口,从而可提高深水钻井时效。

Interaction of hypertension and diabetes on impairment of endothelial function

Objective To investigate whether the interaction of hypertension and diabetes aggravates endothelial dysfunction and leads to smooth muscle dysfunction. Methods Noninvasive methods were used to the investigated patients with type 2 diabetes mellitus (2-DM) (Group 1), patients with hypertension (Group 2) and patients with both 2-DM and hypertension (Group 3), as well as a normal control group (Group 4) by studying a brachial artery without evidence of atherosclerotic plaque formation. Results Results showed that endothelium-dependent vasodilation decreased significantly in Group 1 (5.74%±3.32%, P<0.05), Group 2 (4.14%±2.93%, P<0.01), and Group 3 (2.78%±2.08%, P<0.001) as compared to the control (9.45%±3.88%). The nitroglycerin-induced vasodilation (smooth muscle function) in Group 3 was significantly decreased as compared to the control group (14.11%±4.63% vs 23.53%±6.77%, P<0.001), but there were no differences in nitroglycerin-induced vasodilation between Group 1, Group 2 and Group 4. On univariate analysis, a reduced vasodilator response to nitroglycerin was associated with endothelium-dependent vasodilation (r=0.54, P<0.001). Conclusion Our results indicate that the interaction of 2-DM and hypertension aggravates endothelial dysfunction and further impairs the smooth muscle function.

Effect of Yinian Jiangya Yin on Primary Hypertension in Early Stage—A Clinical Observations on 40 Patients

Objective: To observe the effect of Yinian Jiangya Yin (Decoction for lowering blood pressure to prolong life) on patients with early hypertension and its mechanism on the function of vascular endotheliocytes. Methods: The 79 patients with early primary hypertension belonging to the TCM syndrome of stagnation of phlegm and blood stasis in meridians and hyperactivity of the liver-yang were randomly divided into a treatment group of 40 patients treated with Yinian Jiangya Yin and a control group of 39 patients treated with Tianma Gouteng Yin (Decoction of Gastrodia and Uncaria). The changes in score of TCM syndrome and in blood pressure before and after treatment were observed in the two groups. The contents of nitrogen monoxide (NO) and endothelin (ET) in serum after treatment were determined. Results: There was a statistical difference (P<0.05) in score of TCM syndrome, effect of lowering blood pressure, and the contents of ET and NO in serum after treatment between the two groups. Conclusion: The effect of Yinian Jiangya Yin on improving TCM syndrome of patients with primary hypertension in early stage and on lowering blood pressure may be related to its regulating the imbalanced condition between ET and NO for restoring the function of endothelium-dependent vasodilation.

Effect of Huanglian Jiedu Decoction on vascular endothelium factor and expression of RhoA protein factor in young spontaneously hypertensive rats

To investigate the mechanism of effect of Huanglian Jiedu Decoction(HLJD) on vascular endothelium, we assessed the protective effect of HLJD on vascular endothelium in spontaneously hypertensive rats(SHR) and the expression of RhoA in thoracic aorta. A total of 40 SHR rats were randomly and evenly divided into model group(SHR group), positive group(captopril group), HLJD high-dose group, and HLJD low-dose group. Simultaneously, 10 Wistar Kyoto rats were used in the blank group. All groups were treated by gavage for 6 weeks. The changes of nitric oxide synthase(NOS), von Willebrand factor(vWF), endothelin(ET-1) and calmodulin(CAM) in rat serum were tested by enzyme linked immunosorbent assay(ELISA) method. The expression of RhoA at the protein and mRNA levels in thoracic aorta was determined by Western blotting(WB) and quantitative real-time PCR, respectively. Compare with the blank group after 6 weeks, the levels of ET-l and VWF in serum of the model group were significantly increased(P<0.01), and the levels of NOS and CAM were significantly decreased(P<0.01). Conversely, the levels of ET-1 and vWF in the positive and HLJD groups were significantly decreased(P<0.01 or P<0.05), and the levels of NOS and CAM were significantly increased(P<0.01 or P<0.05) compared with the model group. The expression of Rho A at the mRNA and protein levels was decreased obviously(P<0.05) in HLJD high-dose group. The results shown that HLJD increased diastolic factor(CAM and NOS) in the vascular endothelial of rats, leading to reduced contraction factor(ET-1 and vWF). HLJD revealed the preventive function in the vascular endothelial dysfunction of the early stage hypertension through adjusting secretion of blood vessel endothelium(BVE) relaxing factor and improving vascular endothelial function. The mechanism might be associated with the inhibition of the activity of RhoA protein factor.