Evaluation of myocardial perfusion in patients with coronary slow flow by myocardial contrast echocardiography / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore myocardial perfusion of patients with coronary slow flow (CSF) using myocardial contrast echocardiography.</p><p><b>METHODS</b>Myocardial contrast echocardiography was performed in coronary artery angiography diagnosed CSF patients (n = 20) and control patients (n = 20). The images at baseline and after low dose dobutamine stress test were analyzed by automatic tracking software and the maximal amplitude score A, the mean ascending slope of the curve β and the product of A×β were measured. The reserve of A×β was also calculated. Electrocardiogram at rest and at each stage of dobutamine stress test was obtained simultaneously.</p><p><b>RESULTS</b>At baseline, the A [(6.85 ± 2.99) dB vs. (7.01 ± 3.49) dB], β[(0.59 ± 0.33)/s vs. (0.61 ± 0.38)/s] and A×β [(3.48 ± 1.46) dB/s vs. (3.31 ± 0.96) dB/s] values were similar between CSF group and control group (all P > 0.05). After dobutamine stress test, both β and A×β were significantly increased in two groups. The β [(0.89 ± 0.42)/s vs. (1.31 ± 0.54)/s, P < 0.01] and A×β [(5.82 ± 2.69) dB/s vs. (8.07 ± 2.76)dB/s, P < 0.05] in CSF group were significantly lower than in control group. Electrocardiogram of all the subjects was normal at rest, but the electrocardiogram positive rate was significantly higher in CSF group than in control group after dobutamine stress test (12% vs. 2%, 60% vs. 10%, P < 0.01).</p><p><b>CONCLUSIONS</b>Dobutamine stress test could induce myocardial perfusion abnormalities in patients with coronary slow flow phenomenon.</p>

Echocardiographic assessment of right heart in normal adults / 中华医学超声杂志（电子版）

Objective To discuss the value of echocardiography for the assessment of structure and function of right heart in normal Chinese adults Methods The structure and function of right heart was assessed by echocardiography according to 2010 guideline of American Society of Echocardiography (ASE). The echocardiographic data of right heart of 130 normal Chinese adults were analyzed to acquire the normal reference values of echocardiographic parameters and evaluate the differences of these results among different age groups. Results There were significant differences among different age groups for some of the parameters. Right atrium (RA) transverse diameter was greater in the middle-aged group than that in the young-aged group [(36.90±5.10) mm vs (33.90±5.20) mm, t=-2.79, P=0.006]. RA longitudinal diameter (RAL) and RA area (RAA) were smaller in the young-aged group than those in the middle-aged and old-aged groups [(40.10±5.10) mm vs (42.90±5.10) mm, (43.40±5.60) mm, t=-2.51 and-2.91, P=0.013 and 0.004;(11.90±3.20) mm2 vs (13.40±2.90) mm2, (13.90±3.60) mm2, t=-2.24 and-2.90, P=0.027 and 0.004]. Parasternal long-axis right ventricule outflow tract (PLAX RVOT), parasternal short-axis right ventricule outflow tract (PSAX RVOT) and pulmonary artery diameter (PAD) were smaller in the young-aged group than those in the middle-aged and old-aged groups [(24.20±3.00) mm vs (26.20±2.30) mm, (25.90±2.90) mm, t=-2.80 and-2.32, P=0.006 and 0.022;(24.70±3.00) mm vs (27.20±2.50) mm, (26.90±2.60) mm, t=-4.40 and -3.84, P=0.000 and 0.000; (20.60±2.00) mm vs (22.10±2.70) mm, (21.90±2.10) mm, t=-3.12 and-2.67, P=0.002 and 0.008]. RV lateral wall thickness was smaller in the young-aged group than that in the middle-aged and old-aged groups [(5.10±0.60) mm vs (5.60±0.60) mm, (5.40±0.70) mm, t=-3.12 and-2.22, P=0.02 and 0.028];DTI e wave was greater in the young-aged group than that in the middle-aged and old-aged groups [(14.90±3.70) cm/s vs (10.90±3.10) cm/s, (11.10±2.60) cm/s, t=5.82 and 5.49, P=0.000 and 0.000]. DTI a wave was smaller in the young-aged group than that in the middle-aged and old-aged groups [(12.50±3.90) cm/s vs (14.60±3.70) cm/s, (16.60±3.60) cm/s, t=-2.79 and -5.04, P=0.007 and 0.000] and DTI a wave was smaller in the middle-aged group than that in the old-aged group (t=-2.26, P=0.02). Tricuspid E wave was greater in the young-aged group than that in the middle-aged and old-aged groups [(0.61±0.11) m/s vs (0.51±0.11) m/s, (0.48±0.08) m/s, t=4.58 and 5.44, P=0.000 and 0.000]. E/A was greater in the young-aged group than that in the middle-aged and old-aged groups (1.45±0.30 vs 1.12±0.33, 1.10±0.27, t=4.58 and 5.44, P=0.000 and 0.000). No significant differences were found among different age groups in RV systolic function parameters, whereas a trend of decrease in RV diastolic function was detected. Conclusion Echocardiography can be useful in assessing the structure and function of right heart quantitatively.

Overexpression of SERCA2a by gene transfer enhances myocardial systolic function in canines / 生理学报

The present study is aimed to study the effect of sarcoplasmic reticulum Ca(2+)-ATPase 2a (SERCA2a) gene transfer on the contractile function of isolated cardiomyocytes of canines. The cardiomyocytes were isolated with collagenases. The isolated cardiac cells were divided into untransfected group, empty vector group and SERCA2a-transfected group. Recombinant adenovirus vector carrying enhanced green fluorescent protein gene was used for SERCA2a gene delivery. The expression of SERCA2a protein in cardiomyocytes was determined by Western blot. Contractile function of cardiomyocytes was measured with motion edge-detection system of single cell at 48 h after transfection. The results showed, compared with untransfected group, SERCA2a protein level, percentage of peak contraction amplitude under normal condition, percentages of peak contraction amplitude under Ca(2+) or isoproterenol stimulation, time-to-peak contraction (TTP) and time-to-50% relaxation (R50) in SERCA2a-transfected group all increased significantly. While all the above indices in empty vector group did not show any differences with those in untransfected group. These results suggest that the overexpression of SERCA2a by gene transfer may enhance the contraction function of canine myocardial cells.

The role of melatonin receptor and GABAA receptor in the sleeping time prolonged by melatonin in mice / 中国应用生理学杂志

<p><b>AIM</b>To observe the role of melatonin receptor and GABAA receptor in sleeping time prolonged by melatonin in mice.</p><p><b>METHODS</b>The absence of the righting reflex was considered as the sleep onset and the duration of the loss of the righting reflex was recorded as the sleeping time. The effects of receptor agonist and antagonist on hypnotic activity of melatonin were studied in the paper.</p><p><b>RESULTS</b>Prazosin hydrochloride, the blocker of melatonin 3 receptor, didn't affect the sleeping time prolonged by melatonin in mice. GABA, the endogenous agonist of GABA receptor, significantly potentiated the hypnotic activity of melatonin. When picrotoxin, the ligand of picrotoxin site on GABAA receptor, used together with melatonin, it significantly antagonized the sleeping time prolonged by melatonin, however, bicuculline, the specific antagonist of GABA binding site in GABAA receptor, didn't affect the hypnotic activity of melatonin in mice.</p><p><b>CONCLUSION</b>Melatonin does not exhibit its potentiation sleeping time in mice through melatonin 3 receptor. Hypnotic activity of melatonin may be mediated through picrotoxin site on GABAA receptor.</p>