Objective To evaluate the mechanical characteristics of systolic left ventricular(LV) transmural torsion in different LV electro-mechanical patterns using speckle tracking imaging. Methods Five open-chest canine models were employed for the acquirement of the basal, apical short-axis and four-chamber views of LV during baseline(BASE) and right atrial appendage(RAA), right ventricular apical (RVA), left ventricular lateral wall (LVL) and left ventrieular apical (LVA) pacing. Subendocardial (subend),subepicardial(subepi) and bulk rotation angle(RA) and segmental angle excursion(AE) at basal and apical level were analyzed using a dedicated workstation. LV torsion at different layers and bulk and global LV ejection fraction (EF) were calculated. Results ① There were no significant difference of transmural torsion and RA at basal and apical level between BASE and RAA pacing (P>0.05);② LV torsion of subend, subepi and bulk during RVA pacing were lower than those during RAA pacing(P0.05);LV torsion of subend and bulk during LVA pacing were lower than those during RAA pacing(P0.05);LV RA of subend,subepi and bulk at basal level during RVA and LVA pacing were lower than those during RAA pacing (P<0.05); ③ For normal electro-mechanical pattern, LV torsion of subend were significant higher than that of subepi(P<0.05), there only were a higher tendency for all pacing models (P>0.05); ④AE of segments near the pacing site decreased during different ventricle paeings (P<0.05); ⑤At BASE and during RAA pacing, LV bulk and subepi torsion were positively correlated to EF; RA of subend,subepi and bulk at basal level were positively correlated to EF. Conclusions LV transmual torsion are significantly depressed during RVA and LVA pacing. There is a spatial co-relationship between LV EF and torsion and rotation of bulk and subepi at basal level in normal LV electro-mechanical patterns.

Objective To evaluate the clinic effect of leaflet enlargement with autologous pericardium in repairing mitral valve disease and to describe the technique and discuss its indications. Methods Between July 2004 and June 2008, 45 pa-tients with isolated mitral valve disease, included stenosis in 10 and regurgitation in 35. The causes were congenital heart dis-ease in 8, rheumatic in 21, degenerative in 7 and endecarditis in 9. The procedures were: posterior leaflet enlargement with autologuus pericardium in 14, anterior leaflet enlargement in 8, both anterior and posterior leaflet enlargement in 23. In addi-tion, eye to eye technique was in 12, artificial chordal in 12, chordal transfer in 6, papillary muscle vepesitioning in 4. Mitral anuuloplasty was performed in all cases. Before and after surgery, cardiac function parameters were compared. Results No operative deaths occurred. One case wastransfered to mitral valve replacement due to regurgation, lntraoperative transesophageal echocardiography showed no mitral regurgitation in 38 and small regurgitation in 6 cases. The mean mitral valve effective orifice area(MVEOA) was (2.8±0.6) cm~2, with a mean gradient pressure of (6.21±1.34) mm Hg after operation. The mean followed up was ( 18.0±2.1 ) months. Echocardiography study showed that no mitral regurgitation in 35 cases, slight regurgi-tation in 9, mean mitral effective orifice area was (2.5±0. 8 ) cm~2, mean gradient pressure of (7.21±0. 45 ) mm Hg, no one need reoperation. Postoperative cardiac functions were significantly improved: the average left ventricular end-diastolic diameter (LVEDD) was (48±7) mm [ preoperative (56±6) nun, P <0.05], ejection fraction (EF) was 0.51～0.24( preoperative 0.45± 0.23, P < 0.05 ), the average left atrium diameter ( LA ) was ( 50±11 ) mm [ preoperative ( 62±23 ) mm, P <0. 05 ]. The function of mitral valves was well performed. Conclusion Leaflet enlargement with autologous pericardium com-bined with mitral annuloplasty was effective in repairing of diseased mitral valve. The advantages of the procedure including simplicity, good compatibility, avoiding foreign body and no need for anticoagulation.

Objeetive To evaluate the changes of left ventricular(LV) global and segmental volume, LV outlet pressure and their co-relationship, and to access LV global and segmental systolic function and mechanical asynchrony in different LV electro-mechanical patterns using full volume three-dimensional echocardiography(3DE). Methods Nineteen open-chest canine models were employed for the acquirement of LV full volume dynamic 3DE imaging during right atrial appendage (RAA), right ventricular apical (RVA), LV lateral wall(LVL) and LV apical(LVA). LV outlet end-systolic pressure(ESP) was recorded simultaneously. End-systolic volume (ESV), end-diastolic volume (EDV), global and segmental ejection fraction(EF) and systolic dyssynchrony index(SDI) of LV were measured and calculated using a dedicated workstation. The average ascending rate of LV pressure during systole(+ dp/dt) and the average descending systolic pressure(ESP), + dp/dt and - dp/dt during RVA pacing were lower than those during RAA pacing (P <0.05). SDI during RVA pacing was higher than that during RAA pacing(P<0.05). ESP, + dp/dtand - dp/dt during LVL and LVA pacing were lower than those during RAA pacing (P <0.05). There and LVA pacing was higher than that during RVA pacing (P <0.05),SD1 during LVL pacing was lower than that during RVA pacing (P <0.05), there was no significant difference of SDI between RVA and LVA and LVL pacing. Segmental EF of septum and apex during LVI. pacing were higher than those during LVA pacing (P <0.05). @Segmental EF of anterior and post septum and all apical segments (except lateral wall) during RVA pacing were lower than those during RAA pacing (P <0.05). Segmental EF of lateral and anterior wall during I.VI. pacing were lower than those during RAA pacing (P <0.05). Segmental EF of anterior wall and anterior septum during LVA pacing were lower than those during RAA parameters. Conclusions The global and minority segmental systolic function of LV during RAA pacing could be reduced compared with normal sinus rhythm. All the ventricular pacing worsen LV systolic and diastolic function compared with RAA pacing. LV systolic function during LVL pacing was superior to RVA pacing. During ventricular pacing,the systolic function at nearby segments of the pacing site was depressed.

Objective To assess subendocardial systolic circumferential strain(CS),radial strain(RS)and radial displacement(RD)of left ventricle(LV)in short-axis view and LV global systolic function in open-chest canine model with acute myocardial ischemia using velocity vector imaging(VVI),and to establish their spatial correlationships.Methods Left anterior descending coronary artery(LAD)was ligated for 20 minutes to induce acute myocardial ischemia in 12 open-chest canine model.At baseline and 20 minutes after ischemia,two-dimensional dynamic gray-scale images of three standard left ventricular short-axis views at the levels of mitral annulus,papillary muscle and apex and the images of LV apical fourchamber and two-chamber view were acquired and transfefred to VVI workstation for off-line analysis.Peak systolic CS,RS and RD of eighteen segments and of three global short-axis sections of LV were measured at subendocardium.and LV ejection fraction(LVEF)and stroke volume(SV)were calculated using Simpson's method.The differences and correlationships were analyzed between them.Resuls Compared with the value at baseline,LVEF decreased significantly(P＜0.05)after ischemia.The peak systolic subendocardial CS,RS and RD of the affected segments,global CS,RD at papillary muscle and apex views and global RS at apex view were significantly lower than those at baseline after ischemia(P＜0.05).There was a good linear correlationship between the peak systolic CS and RD of 17 segments(except the middle segment of LV lateral wall after ischemia)and each global short-axis level before and after ischemia(r=0.662-0.995,P＜0.05,P＜0.01 or P＜0.001),The peak systolic RS of six segments and each global short-axis level(except the apex level at baseline)was correlated with RD(r=0.580-0.916,P＜0.05,P＜0.01 or P＜0.001);There was not statistical correlationship between global RDs and SV as well as LVEF.Conclusions Subendocardial circumferential strain and radial displacement may sensitively reflect the changes of regional and global myocardial systolic function induced by acute myocardial ischemia.The significant correlationship between subendocardial circumferential systolic strain and radial displacement might indicate that circumferential deformation of myocardium result in the changes of the radial displacement mainly.

Objective To investigate the role of a small RNA interference against VEGF in radiation sensitivity in melanoma .Methods A375 human melanoma cell lines were transplanted into nude mice ,which with malignant melanoma were randomly divided into control group , VEGF negative plasmid group and VEGF positive plasmid group, followed by 4Gy irradiation twice a week for 2 weeks.The volume of tumor was calculated twice a week, the area of tumor necrosis was assayed by HE,the expression of VEGF in tumor was determined by Western-blot and Immunohistochemical. ResuIts The expression of VEGF in VEGF positive plasmid group decreased significantly (P<0.05), VEGF positive group had more tissue necrosis, tumor growth was significantly inhibited (P<0.05).ConcIusion siRNA-VEGF in tumor injection liposome encapsulated in malignant melanoma has a role in the radiation sensitization, which provides an experimental basis for the clinical development of targeted therapy combined with radiotherapy for the treatment of VEGF gene.

Objective To evaluate the changes of peak segmental and transmural radial displacement (RD) of left ventricle(LV) during acute myocardial ischemia with different LV pacing patterns. Methods Left anterior descending coronary artery (LAD) was ligated to induce acute myocardial ischemia in open-chest Beagle canine models ( n=10). Two-dimensional gray-scale images with overlaid tissue Doppler velocity imaging in three standard LV short-axis views were acquired with different pacing patterns in a randomized sequence in three complete cardiac cycles. Parameters including peak RD, peak RD time(RD-Tc) ,the standard deviation of TC(RD-TSD) of 12 segments and their myocardial layers(subend,mid,subepi) were measured and analyzed using TDI-Q workstation. Results ① There were no significant differences of peak RD between three myocardial layers of LV wall in each different pacing pattern group;There were no significant difference of peak RD from segments and transmural layers among the different LV pacing patterns. ②With acute myocardial ischemia the RD correlation of LV lateral pacing( LVL-P) and LV border pacing(LVB-P) patterns were higher than that of LV apical pacing(LVA-P) pattern between global segment and its subend, mid, subepi. ③ RD-Tc of 12 LV segments and their subend, mid, subepi appeared after T wave and there were no significant differences of RD-Tc among different LV pacing patterns. ④RD-TSD of the corresponding segments during LVL-P,LVA-P and LVB-P patterns were significant lower than those during acute yocardial ischemia(P<0. 05). Conclusions The existed RD correlation of LVA-P between subend.mid, subepi and the segment were lowest among the different ischemic LV pacing patterns; the synchronization of transmural RD could be recovered partly with LVL-P, LVA-P and LVB-P patterns. The echocardiographic study of LV transmural RD might be useful to reveal the segmental and the transmural myocardial mechanical state with different LV pacing patterns during acute ischemia in detail.

Objective To compare the degree of cell injury induced by 3D protein (SDLY11 and SDLY107) of enterovirus 71 (EV71) strains.Methods EV71 strains SDLY11 and SDLY107 were respectively isolated from children with mild and severe hand foot mouth disease.The target genes 11-3D-Flag and 107-3D-Flag were amplified by reverse transcription-polymerase chain reation (RT-PCR) and inserted into the eukaryotic expression vector pcDNA3.1.The recombinant plasmids 11-3D-Flag-pcDNA3.1 and 107-3D-Flag-pcDNA3.1 were transformed into Escherichia.coli DH5α, respectively, and were identified by enzyme digestion and sequencing.The recombinant plasmids were transfected into rhabdomyosarcoma (RD) cells, respectively.Expression of 3D protein was detected by indirect immunofluorescence assay and western blot.Cell injury induced by 3D protein was detected with lactate dehydrogenase (LDH) test, cell proliferation was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenylthiazolium bromide (MTT) test, and cell apoptosis was detected with Annexin-V and PI.Multiple comparisons among groups were analyzed using LSD-t test if multiple sets of variables were consistent with homogeneity of variance.If not, Dunnett T3 test was used.Results The 1 400 bp fragments were amplified by reverse tramscription (RT)-polymerase chain reaction (PCR), and the recombinant plasmids were digested by enzyme and the 1 400 bp and 5 400 bp fragments were obtained and identified.Gene sequencing showed that the sequences were consistent with the target genes.The specific fluorescence was observed by indirect immunofluorescence assay, and the western blot showed that the molecular weight of the target protein was 55×103.The LDH test showed that the A490 of SDLY11 3D protein transfection group (0.790±0.048) was higher than that of SDLY107 3D protein transfection group (0.641±0.018).The difference was statistically significant (t=5.14, P<0.05).The cell membrane damage caused by SDLY11 3D protein was more severe than SDLY107 3D protein.The MTT test showed that the A570 of SDLY11 3D protein transfection group (1.028±0.020) was lower than that of SDLY107 3D protein transfection group (1.081±0.002), and the difference was statistically significant (t=3.31, P<0.05).The effect on cell proliferation activity of SDLY11 3D protein was greater than SDLY107 3D protein.The results of Annexin-V/PI showed that the percentage of apoptotic cells of SDLY11 3D protein transfection group and SDLY107 3D protein transfection group were (1.471±0.246)% and (1.465±0.237)%, respectively, and the difference was not statistically significant (t=0.04, P=0.973).Conclusions Compared with the SDLY11 3D protein, SDLY107 3D protein induces slighter cell injury, has weaker effect on cell proliferation activity, and is more favorable for virus replication in cells.

Pyroptosis is a type of programmed cell death distincted from apoptosis and necrosis, which is accompanied by the lysis of cell membranes and the release of cell contents. Pyroptosis occurs as mediated by Gasdermin protein family and is dependent on the activity of caspase. GSDME is one of the most important members of the Gasdermin protein superfamily. GSDME-mediated pyroptosis relies on the activity of caspase-3. In recent years, with further research on pyroptosis, the mechanism of GSDME-induced pyroptosis is becoming clear. Numerous studies have shown that GSDME-mediated pyroptosis plays an important role in the occurrence and development of tumors, as well as chemotherapy resistance. However, GSDME-mediated pyroptosis has no specificity and can induce pyroptosis of normal cells in the body while inducing tumor cell pyroptosis, thus causing different degrees of damage to various organs of the body. Further study on the mechanism of GSDME-induced pyroptosis, the role of GSDME in malignant tumors and the adverse reactions of chemotherapy can provide new ideas for tumor monitoring, treatment and prognosis judgment.

Exosomes are membranous vesicles secreted by most eukaryotic cells, which are approximately 30-150 nm in diameter and contain RNA, proteins and lipids closely related to their function and origin, playing an important role in cell-to-cell communication. It can promote tumor progression by promoting the proliferation and migration of tumor cells, improving the tumor microenvironment and inhibiting the immune response. In addition, exosomes are expressed at high levels in certain tumors and can be used as predictors of cancer for early diagnosis. It can also be used as a carrier to carry targeted drugs to the local tumor to exert an inhibitory effect.

Objective: To investigate the development of hepatocyte senescence during liver fibrogenesis and to explore the effect and possible mechanism of insulin-like growth factor 1 (IGF-1) on hepatocyte senescence and liver fibrosis. Methods: A total of 42 male Sprague Dawley (SD) rats were selected. Eighteen rats were induced by carbon tetrachloride (CCl₄) to establish the rat model of liver fibrosis. On the day 0, six and 28 after the establishment of the model, six rats were executed respectively to analyze the liver fibrosis and hepatocyte senescence in CCl₄-induced liver fibrosis rat models. Twenty-four rats were divided into control group, CCl₄ group, CCl₄+ lentivirus vector (LV-CTR) group and CCl₄+ LV-IGF-1 group, with six rats in each group.The rats were sacrificed on the 28th day after the establishment of the model. The liver tissues were obtained and the inferior vena cava blood was collected to analyze the effect of IGF-1 overexpression on liver fibrosis and hepatocyte senescence. Analysis variance (ANOVA), least significant difference (LSD) and Dunnett T3 test were performed for statistical analysis. Results: Steatohepatitis on the 6th day and early stage of hepatic fibrosis on the 28th day, which indicated the model was successfully established. The results of the effects of IGF-1 overexpression on hepatic fibrosis and hepatocyte senescence showed that on the 28th day, compared with those of control group, both the score of Ishak liver inflammation and necrosis and the score of Ishak liver fibrosis were increased in the CCl₄ group, CCl₄+ LV-CTR group and CCl₄+ LV-IGF-1 group (0, 14.55±1.94, 15.43±2.19 and 10.29±1.47, respectively; 0, 3.51±0.51, 3.21±0.79 and 1.32±0.40, respectively). The area of liver tissues by Masson staining (0.45±0.40, 5.62±1.08, 6.03±0.65 and 2.88±1.54), SA-β-Gal staining (1.75±0.80, 4.28±1.19, 4.92±1.14, 3.11±0.79), p53 (2.02±0.81, 4.36±1.02, 4.72±0.72 and 3.58±0.70) and progerin (0.72±0.40, 4.52±1.01, 4.01±1.25 and 2.66±0.80) all were increased. The levels of serum IGF-1 all were decreased ((632.00±6.04), (503.00±40.42), (508.00±21.94) and (572.40±5.94) ng/L). However the levels of ALT all were increased ((11.20±5.97), (214.00±73.90), (245.00±76.06) and (30.00±5.00) U/L). The relative expression levels of p53 (0.58±0.06, 1.78±0.18, 1.72±0.10 and 1.23±0.22) and progerin (0.12±0.02, 0.78±0.15, 1.32±0.20 and 0.81±0.16) in the primary hepatocytes were increased. The differences were all statistically significant (F=91.674, 90.778, 32.982, 9.726, 10.640, 17.029, 103.910, 30.059, 64.707 and 97.457, all P<0.05). Compared with those of CCl₄+ LV-CTR group, the score of Ishak liver inflammation and necrosis and the score of Ishak liver fibrosis were decreased in the rats′ liver tissues of CCl₄+ LV-IGF-1 group, the areas of Masson staining, SA-β-Gal staining, p53 and progerin in the liver tissues were decreased, the level of serum IGF-1 was increased, the level of ALT was decreased, and the relative expression levels of p53 and progerin in primary hepatocytes both were decreased. The differences were all statistically significant (all P<0.05, respectively). Conclusions Hepatocyte senescence increases in the process of liver fibrosis induced by CCl₄. Overexpression of IGF-1 may alleviate liver injury, improve hepatocyte senescence and liver fibrogenesis by regulating the nuclear p53/progerin pathway.