Initial experience of transcatheter implantation with a new aortic valve in sheep / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility and short-term results of transcatheter aortic valve implantation (TAVI) using a new transcatheter valve.</p><p><b>METHODS</b>Twenty healthy adult sheep received general anesthesia. Under the guidance of X-ray and transthoracic echocardiography (TTE), the new anti-calcification transcatheter valve was released from delivery system and implanted at the level of native aortic annulus via left common carotid artery. Position and function of the new anti-calcification transcatheter valve were evaluated by angiography and TTE immediately after intervention. Thirty day survival rate of animals was obtained.</p><p><b>RESULTS</b>New transcatheter valves were implanted in all sheep. Fifteen sheep (75%) survived up to 30 days and post-operative examination showed that the transcatheter valve was in optimal position without migration and mitral valve impingement. The native coronary artery was patent in these animals. There was a slight paravalvular leak in 5 sheep. Postoperative echocardiography showed reflux percentage was significantly increased (P < 0.05) compared pre-intervention. Effective orifice area, aortic systolic pressure, diastolic aortic pressure, mean aortic pressure, left ventricular systolic pressure, left ventricular end diastolic pressure and heart rate were similar between post and pre-intervention (all P < 0.05). Five sheep died after TAVI within 30 days, including one fatal ventricular fibrillation occurred immediately after releasing the transcatheter valve and another sheep died of acute myocardial infarction due to left main coronary artery occlusion evidenced by angiography. Two sheep died of severe mitral regurgitation at 8 and 12 hours post-operation and one died of infective endocarditis at 26 days after intervention.</p><p><b>CONCLUSION</b>Our favorable preliminary results showed that it was feasible to perform TAVI using the new transcatheter valve.</p>

The effects of urea on ECG and the sodium currents of ventricular myocyte in mice / 中国应用生理学杂志

<p><b>AIM</b>To observe the effects of urea on ECG and sodium currents of ventricular myocyte in mice.</p><p><b>METHODS</b>ECG and patch clamp techniques were used in the experiments, to record ECG of mice and sodium currents of ventricular myocyte in mice.</p><p><b>RESULTS</b>Urea could lead mice heart rate evidently slow down (P < 0.01) with concentration dependent. The heart rate were (556 +/- 29, 469 +/- 37, 378 +/- 48) b minT in low, middle, high groups respectively before using urea and (612 +/- 27, 615 +/- 23, 619 +/- 26) x min(-1) after. The conduction block arrhythmia was happened in middle and high groups. The sodium currents of ventricular myocyte in mice was inhibited by urea(P < 0.05). The sodium currents amplitude value were reduced to (7.32 +/- 0.68, 5.69 +/- 0.64, 4.58 +/- 0.57) nA after using urea in each group and were (8.76 +/- 0.91, 8.87 +/- 1.01, 8.77 +/- 0.96) nA before, submit concentration dependent.</p><p><b>CONCLUSION</b>Urea can inhibit the sodium currents of ventricular myocyte in mice to make it happen conduction block arrhythmia.</p>

Changes of dopamine transporter function in striatum during acute morphine addiction and its abstinence in rhesus monkey / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although dopamine transporter (DAT) is essential for addiction, the effect of additive drugs on DAT function is still controversial, especially for opiates. We investigated the functional changes of dopamine transporter in striatum of rhesus monkeys during acute morphine injection and its abstinence.</p><p><b>METHODS</b>Four rhesus monkeys, 6 to 9 years old, two male and two female, were examined for 12 days. Single photon emission computed tomography (SPECT) was performed with (99)T(cm)-TRODAT-1 as the radiopharmaceutical dopamine transporter agent during different stages of acute morphine injection and its abstinence. The ratios of SPECT signal between striatum and cerebellum (ST/CB) were calculated.</p><p><b>RESULTS</b>The ST/CB ratio declined significantly on the first day of morphine injection and continued declining with more morphine injections. After abstinence, the ratio increased with time, but was still significantly lower on the 5th day of abstinence than the normal level.</p><p><b>CONCLUSIONS</b>In rhesus monkey, acute morphine injection has both rapid and lasting effects on DAT by downregulating its function. The decline was partially reversible following morphine abstinence. The results suggest that striatum is one effective target of morphine and that the DAT function in striatum is one indicator for morphine addiction.</p>

Specific neural basis of Chinese idioms processing:an event-related functional MRI study / 中华放射学杂志

Objective To address the neural basis of Chinese idioms processing with different kinds of stimuli using an event-related fMRI design.Methods Sixteen native Chinese speakers were asked to perform a semantic decision task during fMRI scanning.Three kinds of stimuli were used: Real idioms (Real-idiom condition);Literally plausible phrases (Pseudo-idiom condition,the last character of a real idiom was replaced by a character with similar meaning);Literally implausible strings (Non-idiom condition,the last character of a real idiom was replaced by a character with unrelated meaning).Reaction time and correct rate were recorded at the same time.Results The error rate was 2.6%,5.2% and 0.9% (F = 3.51,P0.05 )for real idioms,pseudo-idioms and wrong idioms, respectively.Similar neural network was activated in all of the three conditions.However,the right hippocampus was only activated in the real idiom condition,and significant activations were found in anterior portion of left inferior frontal gyrus (BA47)in real-and pseudo-idiom conditions,but not in non-idiom condition.Conclusion The right hippocampus plays a specific role in the particular wording of the Chinese idioms.And the left anterior inferior frontal gyms (BA47)may be engaged in the semantic processing of Chinese idioms.The results support the notion that there were specific neural bases for Chinese idioms processing.