miRNAs were discovered less than a decade ago, and have emerged as important regulators of gene expression in mammals. A large number of miRNAs have been identified to be located within the intronic regions of protein-encoding genes(host genes) and called intronic miRNAs. The intronic miRNAs may play a key role in regulating the expression and function of their host genes due to the fact that most of them are co-expressed with the host genes. In this paper, the recent advances on the research on potential relationship between intronic miRNAs and their host genes are reviewed.

Objective The studies on tissue culture and cytological observations of leaf explants of Curculigo orchioides were conducted in order to provide the basis for the rapid propagation of C. orchioides. Methods Young leaf explants of C. orchioides were cultured on MS basal media. Differences in the callus induction and plantlet regeneration rate were observed by different light treatment as well as chemical factors like different phytohormones, casein hydrolysate (CH), and activated charcoal (AC) concentrations. Paraffin method was used to cytological observation. Results For callus induction of leaf explants of C. orchioides, dark treatment gave better results compared to light treatment; among the media tested, the suitable phytohormone combinations were 2.0 mg/L 2, 4-D or 6-BA 1.5 mg/L+2, 4-D 2.5 mg/L, and 300 mg/L CH+0.2% AC was good for plantlet regeneration from leaf explants. The callus from leaf explants mainly originated from midrib. The parenchyma cells near epicuticle of midrib firstly were initiated to division. Then the parenchyma cells of vascular bundle sheath and mesophyll cells on each side of vascular bundle were also divided to form callus. The buds developed on the peripheral parts of the calli, but the roots developed in the regions deep within the calli. Conclusion Tissue culture of young leaf explants of C. orchioides can make the propagation of C. orchioides rapid.

Objective To evaluate the function and synchronization in patients with paroxysmal atrial fibrillation(PAF) by two dimensional speckle tracking imaging(2D-STI) measuring the strain of left atrial.Methods Thirty healthy controls and thirty-five patients with PAF were studied.The PAFs were divided into group PAF1 during the diapause and group PAF2 during the stage of attack.From the strain-time curve of 2D-STI workstation,the peak velocity(Vs,Ve and Va),the peak amplitude of longitudinal strain (Ss,Se and Sa) and strain rate (SRs,SRe and SRa) were acquired in the course of systole,the early and the late diastole respectively.The synchronization of left atrial (Ts-SD,Te-SD and Ta-SD) could be gotten from the time to the peak strain.The correlation were analysed between the synchronization indices and the strain rate parameters.Results ①No significant differences were found at the age,heart rate,E/A,IVS,LVEDD and LVEF.Compared with the control group,the LAD increased and DT decreased in PAF1 and PAF2 groups (P ＜0.05).②The peak velocity were slower,the peak strain were shorter and the peak strain rate were lessened in the PAFs than the controls(P ＜0.05),except the SRa(P ＞0.05).③The Ts-SD and Te-SD were much more different during the three groups(P ＜0.05),the PAF2 showed fewer synchronization; the Ta-SD was higher in the PAF1 than the controls(P ＜0.05).④The Ta-SD had a positive correlation with SRa(r =0.61,P ＜0.01).Conclusions The reservoir and conduit function of left atrial are impaired in PAFs during the diapause,the booster pump could recover partially,however,there are dyssynchronization.The booster pump function disappear during the stage of attack and there are worse synchronization.2D-STI may paly important roles in the assessment of function and synchronization of left atrial.

Objective To assess left ventricular function early and late improvement of patients with acute myocardial infarction (AMI) treated by percutaneous coronary intervention (PCI) by speckle tracking imaging (STI).The clinical values of the assessment of STI for the prognosis and heart function improvement of AMI patients treated by PCI were discussed.Methods 73 AMI patients who had AMI for the first time and had been treated by primary PCI from September 2010 to July 2011 and were examined in the follow-ups from December 2010 to February 2012 in our hospital were enrolled.Dynamic images were acquired before PCI,at 3 months and 6 months after PCI and analyzed by STI.Dynamic images were analyzed for longitudinal peak systolic strain (LPSS),radial peak systolic strain (RPSS) and circumferential peak systolic strain (CPSS) values by STI.According to the comparison of left ventricular ejection fraction (LVEF) before PCI and 6 months after PCI,patients were divided into left ventricular function improved group (ΔLVEF6＞5％) and not-improved group.According to the comparison of LVEF before PCI and 3 months after PCI,improved group were divided into left ventricular function early-improved group (ΔLVEF3 ＞5％) and late-improved group.Results The values of all STI parameters before PCI,3 months and 6 months after PCI in improved group were higher than those in not-improved group (P ＜0.001,all).LPSS before PCI and at the follow-ups and RPSS at 3 months after PCI in early-improved group were higher than those in late-improved group (LPSS at 3 months after PCI:P＜0.001;Other parameters:P ＜0.05).There were significant correlations between all STI parameters and both ΔLVEF3 and ΔLVEF6.LPSS before PCI was more closely related to ΔLVEF3 (r =-0.781,P ＜0.001).CPSS at 6 months after PCI was more closely related to ΔLVEF6 (r =-0.834,P ＜ 0.001).Conclusions Early and late function improvement of left ventricle in AMI patients who is treated by PCI are accurately assessed by STI.The precise analyses of longitudinal and circumferential movements in STI are important for clinical diagnosis.

Objective To assess the left ventricular function of patients with acute myocardial infarction (AMI) treated by percutaneous coronary intervention (PCI) by speckle tracking imaging (STI).Methods 75 AMI patients who had AMI for the first time and have been treated by primary PCI were enrolled.Dynamic images were acquired before PCI,at 6 months after PCI and analyzed by STI.Dynamic images were analyzed for longitudinal peak systolic strain (LPSS),radial peak systolic strain (RPSS) and circumferential peak systolic strain (CPSS) values by STI.According to the comparison of left ventricular ejection fraction (LVEF) before PCI and 6 months after PCI,patients were divided into left ventricular function improved group (△LVEF≥5％) and not-improved group.Results Compared to non-improved group,LPSS (P ＜0.001),RPSS (P ＜0.05,P ＜0.001) and CPSS (P ＜0.001) of improved group were all higher before and 6 months after PCI.LPSS (r =-0.578,P ＜0.001) and CPSS (r =-0.817,P ＜0.001) before PCI were both closely related to △LVEF.In single parameter mode of ROC curve analysis,the area under the ROC curve (AUC) (0.867),sensitivity (94.7％) and specificity (74.4％) of CPSS are relatively higher than other STI parameters.In multiple parameters united mode of ROC curve analysis,AUC (0.897),sensitivity (94.7％) and specificity (74.4％) of LPSS,RPSS and CPSS united were the highest among all the combinations of all STI parameters.Conclusions Left ventricular function improvement of patients with AMI 6 months after PCI is accurately assessed and predicted by STI.CPSS is a strong predictor for left ventricular function improvement 6 months after PCI of AMI patients among all the STI parameters and is an effective indicator for the assessment of left ventricular function improvement of AMI patients.

This paper discussed the main point specifically from the three aspects which are the certainty and uncertainty of technological function , the predictability and unpredictability of technological efficiency , and“should do”or“not should do”of technological application .It presented an ethics argument of medical technology clinical admittance restriction and defends the standpoint -what we can do does not mean what we should do , aiming to provide moral theoretical support of ethical review of medical technology application .

Objective To evaluate left atrial function in patients with ischemic cardiomyopathy(ICM)and dilated cardiomyopathy(DCM)by two dimensional-speckle tracking imaging(2D-STI).Methods Twenty-two patients with ICM,twenty-six with DCM and thirty-two healthy subjects were studied.The maximum volume(LAVmax),minimum volume(LAVmin)and volume before the systole(LAVp)of left atria were acquired using biplane area-length method,and calculated the total emptying volume(LATV),expansion index(AEI),active emptying volume(LAEV)and fraction(LAEF)of left atria.The strain and strain rate during systole and late of diastole(Ss,SRs,Sa and SRa)were measured at each left atrial wall (septal,lateral,anterior and inferior).The average of them were worked out.The correlation of left atrial function and strain rate were analysed.Results ①No significant differences were found at the age,sex,heart rate and the E wave between the mitral leaflet tips during all the groups.Compared with the control group,the peak of A wave,the deceleration time of E wave and LVEF decreased in ICM and DCM groups,while the LAD,LVEDD and E/A increased significantly in the two groups(P＜0.05).There were no significant differences between ICM and DCM.②Compared with the controls,the LAVmax increased,AEI and LAEF decreased significantly in patients with ICM and DCM,even lower in DCM(p＜0.05).③Compared with the controls,the Ss,SRs,Sa and SRa reduced significantly in patients with ICM and DCM(P＜0.05),and the DCM showed much significant differences than ICM(P＜0.05).④The AEI had a positive correlation with SRs(r =0.765,P＜0.01).The LAEF had a significant correlation with SRa(r =0.830,P＜0.01).Conclusions The accumulation during systole and active emptying function during late of diastole are both lower in ICM and DCM,even worse in the latter.The 2D-STI may paly an important role in the evaluation of left atrial function.

Objective To evaluate the efficacy and safety of domestic left-disk-coated atrial septal occluder on treating patent foramen ovale in a miniswine model. Methods Foramen ovale was punctured in 12 Guangxi BA-MA miniswine and occluded by domestic left-disk-coated atrial septal occluder (Spider~(TM) PFO closure system) under the guidance of fluoroscopy. After occlusion, miniswine were executed after transthoracic echocardiography examination with color Doppler at month 1, 2,3 and 6 respectively for gross inspection and microscopic examinations. Results There were no vegetation, thrombosis, broken stent, or erosion on the surface of all devices. The PFOs were completed occluded as evidenced by transthoracic echocardiography at 1 to 6 months after operation. The surface of the device was fully covered by collagen tissue and endothelial tissue at 1 month after operation and the thickened gradually thereafter. Conclusions The domestic left-disk-coated atrial septal occluder can efficiently occlude patent foramen ovale. Satisfactory biocompatibility, rapid and complete endothelium covering and low incidence of complication are also evidenced for this closure system in our experiment.

Objective To investigate the safety and efficacy of patent foramen ovale ( PFO ) closure with Left-disk-coated PFO occluder. Methods The device was implanted in patients with PFO under the guidance of fluoroscopy and transthoracal echocardiography using a 10-12 French delivery sheath via femoral vein approach. Aspirin (100 mg/d for 6 months) was administered post procedure. Patients were followed clinically and echocardiographically at 24 hours, 1 month, 3months, 6 months, and 12 months after device implantation and yearly thereafter. Results Permanent device implantation failed in one patient (4% ) and succeed in the remaining 24 patients (96% ) . There were no major in-hospital-adverse events or complications ( thromboembolism, occluder dislodgement, infection or myocardial infarction). Seven patients developed transient atrial premature beats or atrial tachycardia during implantation and stopped without medication post procedure. Follow-up [(25 ±12) months] results showed that all occluders were in position and there were no residual shunt, arrhythmia and cerebral vessel events post procedure. Conclusion Left-disk-coated PFO occluder is safe and effective for PFO closure.

Objective To investigate the value of three-dimensional speckle tracking imaging (3D-STI) in assessment of left ventricular (LV) strains. Methods Thirty healthy young adults examined by two-dimensional speckle tracking imaging (2D-STI) and 3D-STI. And the results of LV measurements were compared, which included mean peak systolic longitudinal strains, radial strains and circumferential strains. Also, the time consumption of these two methods was compared. Results The time needed for 3D-STI in acquisition and analysis of the images were (309.3±23.4)s, (305.5±11.2)s, while the time for 2D-STI were (490.6±14.4)s, (1261.4±39.9)s. The differences were signiifcant(t=-21.81, 69.94, both P<0.01). The global mean peak systolic radial strains was (48.59±7.68)%by 3D-STI and (33.25±7.27)%by 2D-STI. The difference was signiifcant(t=9.16, P<0.01). The global mean peak systolic longitudinal and circumferential strains were (-17.66±3.14)%, (-17.13±2.29)% by 3D-STI and (-21.35±2.46)%, (-21.97±3.84)% by 2D-STI. The differences were signiifcant(t=5.33, 5.99, both P < 0.01). The 3D-STI strains were different at different levels of LV. The longitudinal, circumferential and radial 3D-STI strains were largest at middle levels. However, 2D-STI strains didn′ t show such trend. Peak strains measured by 3D-STI and 2D-STI showed high inter-observer and intra-observer agreement in Bland-Altman chart. Conclusion 3D-STI is a novel, convenient and reproducible method to evaluate the strains of LV.