Effects of cardiac resynchronization therapy on cardiac function and arrhythmia of patients with chronic heart failure / 实用医学杂志

Objective To study the effect of cardiac resynchronization therapy (CRT) on the cardiac function and arrhythmias of patients with chronic heart failure and left ventricular systolic dyssynchrony. Methods Thirty-two cases of patients with chronic heart failure and left ventricular systolic dyssynchrony underwent CRT therapy. And LEVESV, LVEDV, LVEF, LVEDD, MRA, LAA, MRA/LAA were detected by echocardiography while the cardiac function was kept stable. Then the left ventricular systolic 12 segment peak time (Ts) was measurements by tissue doppler in all patients, the poor (Ts-maxD) and standard deviation (Ts-SD) were also calculated. The 24-hour ambulatory 12-lead ECG was took postoperation. All the patients were treated by anti-heart failure drugs after CRT pacemeker implantantion. All these indicators were assessed again at 12 weeks later. Results Compared with the previous CRT pacemaker implantation, LVEF, LV dp/dpsignificantly increased (P 0.05). Atrial premature beats and paroxysmal atrial tachycardia were significantly reduced in the preoperative CRT (P 0.05). Conclusion CRT resynchronization therapy can improve left ventricular systolic function, and reduce the MRA and Ts. The mechanism may be associated with the improvement of left ventricular synchrony, reducing mitral regurgitation, and reducing the occurrence of atrial arrhythmias.

Upregulation of CD147/MMP-9 pathway attenuates early left ventricular remodeling in rats with spontaneous hypertension / 实用医学杂志

Objective To investigate the effects of CD147/MMP-9 pathway on early left ventricular remodeling Methods 30 healthy eight-week male SHR were divided into 3 groups (n = 10 for each group). SHR group received tail vein injections of normal saline weekly; CD147 group received CD147 of 600 ng·kg-1 weekly; and CD147+DOX group received CD147 of 600 ng/kg weekly and intragastric administration of DOX ( doxycycline ) of 30 mg/kg daily . 10 healthy eight-week male Wistar-Kyoto rats (WKY group) were treated as SHR group. Echocardiography, myocardial sections microscopy examination (HE and VG stain), and Western blot (for assessing levels of MMP-9, TIMP-1, CD147, and collagen I and Ⅲin myocardial tissues) were performed on day 56. Left ventricular weight index (LVWI)was measured and calculated. Collagen volume fractions (CVF) were obtained by image analysis. Results As compared with WKY group , levels of CD147 , MMP-9 , and MMP-9/TIMP-1 were lower but TIMP-1 and collagenⅠand Ⅲ were significantly higher in SHR group. The abundance of CD147 and MMP-9 protein and the ratio of MMP-9/TIMP-1 were obviously increased in CD147 group than in SHR group (P < 0.05). Levels of CD147, MMP-9, and MMP-9/TIMP-1 did no differ between CD147+DOX group and CD147 group. LVWI and contents of collagenⅠand Ⅲ were obviously declined in CD147 group as compare with SHR group. Cardiomyocyte hypertrophy , partial myocardial fibre rupture , myocyte dissolution and fuzzy myocardial fibre boundaries , more abundant of collagen fibers, and higher CVF were found in SHR group. Cardiac fibrosis was significantly improved after CD147 intervention, but the action was suppressed as DOX was administrated simultaneously. Conclusions Early ventricular remodeling may be involved in the inhibition of CD147/MMP-9 pathway in SHR. Input of CD147 to upregulate the pathway can improve the remodeling.

Agrobacterium-mediated transformation of Cymbidium sinensis / 生物工程学报

Genetic transformation is an effective method to improve breeding objective traits of orchids. However, there is little information about genetic transformation of Cymbidium sinensis. Rhizomes from shoot-tip culture of C. sinensis cv. 'Qijianbaimo' were used to establish a practical transformation protocol of C. sinensis. Pre-culture time, concentration and treating methods of acetosyringone, concentration of infection bacteria fluid (OD600), infection time, and co-culture time had significant effects on β-glucuronidase (GUS) transient expression rate of C. sinensis cv. 'Qijianbaimo' rhizome. The GUS transient expression rate of rhizome was the highest (11.67%) when rhizomes pre-cultured for 39 d were soaked in bacterium suspension (OD600 = 0.9) supplemented with 200 μmol/L acetosyringone for 35 min, followed by culturing on co-culture medium supplemented with 200 μmol/L acetosyringone for 7 d. Under this transformation conditions, 3 transgenic plantlets, confirmed by GUS histochemical assay and PCR, were obtained from 400 regenerated plantlets, and the genetic transformation rate was 0.75%. This proved that it was feasible to create new cultivars by the use of Agrobacterium-mediated genetic transformation in C. sinense.

Clinical applications of active fixation at the right ventricular outflow tract using a modified pacing leads model / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the feasibility and safety of using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum.</p><p><b>METHODS</b>A total of 136 patients undergoing artificial heart pacemaker implantation with active fixation pacing leads were randomized into two groups to receive conventional right ventricular outflow tract pacing (CRVOTP) or modified right ventricular outflow tract pacing (MRVOTP). The electrode lead wire core was modeled in a double-curved three-dimensional shape in CRVOTP group and in a J-shaped bend in MRVOTP group before fixation at the right ventricular outflow tract septum.</p><p><b>RESULTS</b>Right ventricular outflow tract septum pacing was achieved successfully in all the patients. None of patients experienced serious complications. No significant differences were found between the two groups in the number of times of electrode fixation, pacing thresholds, impedance, R wave height or QRS wave width during the operation, but MRVOTP was associated with a reduced time of X -ray exposure and operation (P<0.05) due to the convenience in electrode modeling and in passing the leads through the tricuspid annulus and the direct access to the right ventricular outflow tract septum. Postoperative follow-up of the patients showed no incidence of active fixation pacing lead dislocation and comparable pacing thresholds of the ventricular electrodes, impedance, R wave height and QRS wave width between the two groups.</p><p><b>CONCLUTIONS</b>Using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum can reduce the time of X -ray exposure and operation with a low probability of lead damage.</p>

AGE-RELATED CHANGES OF SERUM LIPID PEROXIDE, ANTIOXIDASE, COPPER, ZINC AND SELENIUM / 营养学报

The age-related changes of serum lipid peroxide (LPO), RBC supero-xide dismutase activity (SOD) and glutathione peroxidase activity (GSH-Px), Cu, Zn and Se of blood were observed in 217 normal male persons aged 6~82. It was found that LPO increased significantly with age and SOD, GSH-Px decreased significantly in the elderly (60-70yrs). Blood Zn, Cu and Zn/Cu were highest in the childhood and lowest in the elderly. No significant change of Se with age was observed.The stepwise regression analysis showed that the factors influencing aging mainly were LPO and GSH-Px. It seems that LPO can be used as an indicator of aging.LPO was positively but GSH-Px, SOD, Zn and Cu negatively correlated with aging.