Seed cell, biomaterials, constructing of tissue are three essential elements of tissue engineering. The core is the technology of tissue constructing. Bioreactor for tissue engineering is a sort of systematic equipment constructing ttissues in vitro. Cardiac tissue engineering may hold great potentials for not only replacing or supporting an infarcted cardiac tissue but also treating and saving the lives of patients with heart diseases. This paper mainly introduced the progress of domestic and international technology for constructing engineered cardiac tissue in vitro, especially in the research of bioreactors used for engineered cardiac tissue construction.

Objective:To analyse the functions of two phase media of Liquid and Gel with the Microcolumn Gel Coombs'Test and study the reasons for obviating the need of washing RBC in the Gel Coombs'T.Methods:Add tryplan blue solution into the wider upper portion of the microcolumn gel tube,observe the time of the tryplan blue solution diffusion into the Gel medium at the narrow bottom portion of the tube.Add tryplan blue solution into the liquid reactant in test tube,observe the time of the tryplan blue solution diffusion into the liquid medium.Results:In the Microcolumn of Gel Coombs'Test there is no visual mixing of the two phases for 6 h at lest which is much longer than the incubation time needed for antibody-antigen reaction in routine red cell serology.It takes more than 30 h for the 2 phases to mix.In the test tube of Coombs'Test the tryplan blue solution diffusion into the liquid reactant of serum,red cells and anti-globin reagents and turned to blue colour immediatedly.Conclusion:Two reasons for non-requirement of washing in Gel-Coombs'T have been found.Firstly,there are two phases of reactants in the tubes of cards,the AHG is present in the gel at the narrow bottom portion of the tube,and the RBC,the serum to be detected in the wider upper portion of the tube.Secondly,the gel serves as not only a medium for separating agglutinated RBC from the dispersed RBC,but as a medium for boosting the reactions of AHG with IgG sensitized RBCs.The crux of the two reasons is of the two phases of reactants.

BACKGROUND: At present, osteoarthritis of knee is mainly treated with non-steroid drug in medication, but resulting in the side effects on gastrointestinal tract. The research indicates that bushen yiqi huoxue formula, with litter side effect, improves remarkably pain and motor function of patients with osteoarthritis of knee.OBJECTIVE: To probe into the effect of bushen yiqi huoxue formula on pathological process of the cartilage of knee joint by setting up ostoarthritis of knee in rabbt.DESIGN: Randomized controlled study by observation in which the experimental animals were taken as the objects.SETTING: Animal experimental center of a university.MATERIALS: Totally 36 New Zealand normal male rabbits, weighted varied from 2.0 to 3.0 kg.METHODS: The experiment was performed in Animal Experimental Center of Guangzhou University of Chinese Medicine from January 2002 to January 2003. Thirty-six New Zealand rabbits were involved to set up Hulth knee osteoarthritis model. After operation, they were randomized into 3 groups,named as model group, acetaminophen group and bushen yiqi huoxue formula group (formula group). Adopted corresponding managements in each group,the materials were collected at the 4th, 8th and 12th week after operation for histological pathological assess.MAIN OUTCOME MEASURES: Primary results: integrals of pathological changes in cartilage of joint in every group. Secondary results: ①Naked-eye observation of cartilage of joint in every group. ② Optic microscopic observation of cartilage of joint in every group.RESULTS: The total integrals of pathological changes in cartilage of joint in model group, acetaminophen group and bushen yiqi huoxue formula grcup (formula group) at the 4th week were 18.50±1.00, 14.25±1.26,11.75±2.22 respectively, and 30.75±1.26, 22.00±3.16, 17.75±2. 21 at the 12th week respectively. The total integrals of pathological changes in cartilage of joint, in chondrocyte and in cartilage surface layer are in the sequence of model group ＞ acetaminophen group ＞ formula group successively. The significant or very significant differences present in the comparisons between groups.CONCLUSION: Bushen yiqi huoxue formula delays pathological progression of osteoarthritis of knee so that it can treat and prevent the disease.

Objective To appraise the clinical value of velocity vector imaging(VVI) by analyzing the peak systolic velocities,strain and strain rate of ventricular segments in patients with DDD pacing. Methods eventeen patients with DDD pacing were enrolled in this study. The peak systolic velocities, strain andstrain rate of ventricular segments were measured with VVI. The difference at baseline and after pacemaker implantation was analyzed. Results Left and right ventricular (LV and RV) longitudinal peak velocities at baseline and after DDD pacing were significantly decreasing from basal, mid to apical segments. But no significant difference was found in longitudinal strain,strain rate and radial motion characteristic of LV. The mean systolic velocities and strain rate at baseline and after pacemaker implantation and strain with pacing of RV posterior septum and free wall were higher than those of posterior septum and lateral segment of LV respectively. The mean strain and strain rate of RV after pacing were higher than that of LV. Compared with the values at baseline, mean strain of LV with pacing was lower significantly. Conclusions VVI can accurately assess ventricular systolic function in patients with DDD pacing, and can become a powerful means in assessing the regional myocardial function.

Objective To evaluate the patterns of intracardiac flow of left ventricle (LV) in patients with premature ventricular complexes (PVCs) from the right ventricular outflow tract (RVOT) by analyzing the vortex during isovolumetric contraction phase and the distribution rules of flow-time curves in each layer of LV.Methods Twenty-seven patients with frequent isolated PVCs from RVOT were involved and 25 healthy subjects as control.The color Doppler image of LV at apical four-chamber view was acquired.Vector flow mapping (VFM) was performed to assess the parameters of vortex during isovolumic contraction phase, including diameter (transverse and vertical diameter), velocity (maximal positive and negative velocity) and the number of vortex rings.Positive flow during systole and negative flow during diastole of LV in each layer were measured by flow-time curve.All values of patients with PVCs were recorded during sinus beats (PVC-S) and PVC (PVC-V) respectively.Results Significant differences were demonstrated in all parameters of vortex between the PVC-V and control subjects.And the flow-time curves disarrayed in PVC-V.The velocity of vortex in PVC-S was lower than that in control subjects.And the distribution pattern of flow-time curves in LV of PVC-S differed from that of control subjects.Conclusions Alternation of intracardiac fluid pattern in LV was demonstrated in patients with PVCs from RVOT during both sinus beats and PVC.VFM can be used to analyze the intracardiac flow field in normal and pathological electrical activation.

Objective To assess alternations in left ventricular volume and systolic synchrony in patients with frequent premature ventricular complexes(PVCs) from the right ventricular outflow tract(RVOT).Methods Twenty-nine patients with frequent isolated PVCs from RVOT were included and 30 healthy subjects as control.Instantaneous full-volume imaging(IFI) was performed to evaluate left ventricle volumetric parameters,including end-systolic volume (ESV),end-diastolic volume (EDV),stroke volume (SV),ejection fraction (EF),and systolic synchrony parameters,including systolic dyssynchrony index (SDI),dispersion end-systole (DISPES),mean end-systolic time (MES),pre-contraction time volume (PreContr) and post-contraction time volume (PostContr).Contraction front mapping was performed to visualize volumetric contraction sequence.All values of patients with PVCs were recorded during sinus beats (PVC-S) and premature ventricular beats (PVC-V) respectively.Results Significant differences were observed in left ventricular systolic volumetric and synchrony parameters between PVC-V and control subjects (P＜0.01),as well as in MES and PreContr between PVC-S and control subjects (P＜0.01).Conclusions Left ventricular systolic dysynchrony was demonstrated in patients with PVCs from RVOT.IFI was a novel tool to analyze left ventricular global and regional volumetric alternations.

Objective To evaluate the left ventricular(LV)global and segmental myocardial systolic function in patients with permanent DDD pacemaker implantation by speckle tracking imaging.Methods Myocardial imaging of LV apical long views and parasternal LV short axis views were performed in 9 patients with right ventricular(RV)septum pacing(RV septum group),15 patients with RV apex pacing(RV apex group)and 13 healthy subjects(control group).Peak systolic longitudinal strain(S_L),peak systolic radial strain(S_R)were measured,and the average of S_L and S_R among LV 18 segments were calculated respectively as corresponding GS_L and GS_R.Results The GS_L[-(18.29±2.67)%]of RV apex group showed significant decrease compared with RV septum group[-(20.54±2.29)%]and control group[-(21.07±2.08)%](P＜0.05),while no significant difference was found between RV septum and control group.The GS_R of the pacing groups were both lower than control group[(36.26±9.37)%in control group,(28.59±6.06)%in RV septum group,(26.85±7.73)%in RV apex group,P＜0.05],but RV apex group showed more decrease trend.The S_L and S_R of the LV myocardial segments close to the pacing sites in both pacing groups showed significant decrease compared with control group,but RV septum group preserved similar LV strain distribution with control group while RV apex group showed abnormal LV strain pattern.Conclusions Speckle tracking imaging is a useful modality to evaluate global and segmental myocardial systolic function of LV with pacing at different right ventricular sites.

Aim To study the effects of telmisartan upon serum calcineurin.Methods 92 male SD rats with the same age were randomly divided into control group (N), sham operation group (S), 2K1C+distilled water group (K) and 2K1C+telmisartan group (T).S rats were performed the open-abdomen surgery without being restricted any renal artery, but the K and the T rats were restricted their left renal artery. Beginning from the third week after the surgery, the K rats started to be treated with the intragastric infusion of distilled water 10 ml·(kg·d)~(-1) , while the T rats with telmisartan 10 mg·(kg·d)~(-1) .And after being treated for 2, 4 and 8 weeks, rats were respectively measured the systolic blood pressure (SBP), the diastolic blood pressure (DBP) of the abdominal aorta. Before and after the operation, ultrasonography with probe of 7.5 MHz was used to obtain the structure and functional indexes, such as IVSd, IVSs, LVPWd, and serum calcineurin were evaluated by ELISA and colorimetric assay kit.Result Compared with the S group and the N group, ① the results of blood pressure (SBP, DBP) were significantly higher in K group (all P <0.01), after use of telmisartan, blood pressure was significantly reduced(P <0.01);② the thickness of interventricular septal and left ventricular posterior wall at the end of diastolic and systolic were significantly higher in K group (all P <0.01), after use of telmisartan, the thickness of those declined(all P <0.01);③ the level and activity of serum calcineurin were significantly higher in K group (all P <0.01), after use of telmisartan, the level and activity of calcineurin significantly fell(P <0.01).Conclusion The serum calcineurin of artery was also raised in the left ventricular remodeling. Telmisartan ameliorates ventricular remodeling effectively, which may be associated with decreasing the expression of artery serum calcineurin.

Objective To assess left ventricular(LV)twisting parameters in different layers with velocity vector imaging(VVI)in both healthy subjects and premature ventricular contraction(PVC)bigeminy from right ventricle(RV)patients,and investigate the rules of LV myocardium dynamics in sinus rhythm and PVC from RV.Methods Ten patients with PVC bigeminy from RV and twelve healthy subj ects underwent the examination of two-dimensional ultrasound,in which the standard LV mitral valve(MV)and apical short-axis views were acquired.The twisting angle(TA)and untwisting starting time(UST)were measured.Results In healthy subjects myocardium of LV MV short-axis twisted in clockwise,while the myocardium of LV apical short-axis twisted in counter-clockwise.TA of endocardium was higher than that of epieardium(P＜0.01).In PVC bigeminy from RA patients,their TA during sinus contraction was lower than that of healthy subjects both in MV and apical short axis respectively(P＜0.05),and UST was earlier(P＜0.05).In PVC the TA curve is bidirectional.and in early systolic TA twisted reversely compared with that of healthy subjects and sinus contraction in PVC patients.Conclusions Twisting parameters could be used to assess myocardium dynamics during different ventricular mechanical activation.VVl was a novel tool to analyze myocardium twisting.

Objective To evaluate left ventricular(LV) systolic synchrony and sequence in patients with premature ventricular complexes(PVCs) from right ventricular outflow tract (RVOT).Methods Thirty patients with frequent isolated PVCs from RVOT and 30 healthy subjects as control were included.Speckle tracking imaging (STI) was performed to assess the time-to-peak segmental systolic strain in longit udinal(TsL), circumferential (TsC) and radial (TsR) direction.The standard deviation (SD) of TsL,TsC and TsR of 18 LV segments were calculated respectively.All values of patients with PVCs were recorded during sinus beats(PVC-S) and PVC beats(PVC-V) respectively.LV systolic sequence in PVC-V was analyzed.Results Significant differences were observed in the SD values between the PVC-V and control subjects in three directions,as well as between the PVC-S and control subjects in circumferential and radial direction.In PVC-V significance difference was seen in TsL and TsR from apical to basal level,as well as in TsL and TsC in different walls.Conclusions LV systolic synchrony was demonstrated in patients with PVCs from RVOT during both sinus beats and PVC beats.Systolic sequence in PVC beats from RVOT exhibit certain rules.