Gap junctions(GJ) form the chemical signal channels between cardiocytes.The core proteins of these channels are the connexins(Cx).The quantity or distribution of Cx will lead to the remodeling of GJ, which contributed to arrhythmia and remodeling following the acute myocardial infarction.GJ remodeling is the key reason and pathological basis of arrhythmia following acute myocardial infarction.How to increase the number of myocardial cells and lighten or reverse the heart reconstitution have become a focal point.In the acute myocardial infarction cell transplantation treatment, stem cells are characterized by self-renewal and multi-directional differentiation have been paid great attention.This study summarized the basis and clinical research of GJ structure, function, distribution, remodeling and stem cell transplantation treatment following myocardial infarction.

Biological performances of Ni-Cr porcelain alloy are highly correlated with released metallic ions. Released metal ions from Ni-Cr porcelain alloy, particularly Ni, Be can induce inflammation of the adjacent periodontal tissue and oral mucosa. In vitro evidence has indicated that the immune response can be altered by various metal ions. Allergic reactions due to metallic dental restorations have been documented. Ni has especially been identified as being highly allergenic. The cytotoxicity and corrosion level of Ni-Cr porcelain alloy is increased after recasting. The Ni-Cr porcelain alloy produced according to technology requirements has good biological safety. Ni-Cr porcelain alloy released a few of metal ions which might induce allergy and density of adjacent periodontal tissues, for the stimulation effect of these metal ions. There is no evidence to suggest that Ni-Cr porcelain alloy restorations has systemic toxicity or carcinogenic/genotoxic effect to human.

Objective To evaluate the value of cranial MRI on diagnosing nonalcoholic Wernickes encephalopathy (WE). Methods The clinical characters, cranial MRI features, and outcomes materials in six cases of nonalcoholic Wernickes encephalopathy were analyzed.Results Cranial MR and Flair imaging of the patients exhibited areas of increased T 2W and flair signals symmetrically surrounding the aqueduct and third ventricle and within the medial thalamus. One patient who became persistent vegetative state coexistenced increased T 2W and flair signal of the cortex. According to the follow-up results, the alterations of four patients in T 2W and Flair signals showed to resolve being consistent with the clinical recovery. One patient with persistent vegetative state had no change within two years of the follow-up.Conclusions Cranial MRI is of great value in diagnosing nonalcoholic Wernickes encephalopathy and reflects appropriately the pathological evolution of this disease.

Smooth muscle cell (SMC) proliferation, platelet free calcium level and aggregation of experimental atherosclerotic rabbits were investigated in this study. Aortic SMC ofhyperlipidemic rabbits in vitro showed higher growth activity than did normal rabbit SMC. And also hyperlipidemic serum stimulated SMC to proliferate at a significantly greater rate than control serum. Moreover, the level of platelet free calcium and the platelet aggregation was also higher in hyperlipidemic rabbits, indicating that activitated platelets possibly release more PDGF to act as a stimulator to SMC proliferation and calcium is an important factor to activate platelets. Furthermore, SMC from 8501-treated rabbits appeared lower proliferative rate than thecells from hyperlipidemic rabbits. And serum from those rabbits inhibited SMC proliferation compared with hyperlipidemic serum, the inhibitory effect was even stronger than that of normal serum. It may be relevant to the favorable effects of 8501 to TXA2/PGI2 balance.

Objective To study the effect of Tongxinluo on the plasma C-reactive protein(CRP)and endothelin-1(ET-1)in acute coronary syndrome(ACS) patients.Methods 100 patients with ACS were randomly divided into conventional therapy group and treatment group(conventional therapy+Tongxinluo gelatin capsule).The changes of CRP and ET-1 in the first day,7th and 14th day were observed.Results In the treatment group,CRP and ET-1 were significantly decreased in the 7th and 14th day(P＜0.05,P＜0.01),and there was significant decrease only in the 14th day(P＜0.05)in the conventional therapy group.CRP and ET-1 levels in the treatment group were significantly different as compared with conventional thereapy group(P＜0.01).Conclusion Tongxinluo capsule may protect blood vessel endothelium through inhibiting CRP and ET-1 to decrease the inflammatory response of endangium.

Objective To investigate the effect of microRNA-101 (miRNA-101) on atrial fibrosis in human chronic atrial fibrillation (AF). Methods Right atrial appendages were obtained from 59 patients (30 with AF) undergoing cardiac surgery, including 47 patients with valve heart disease and 12 patients with congenital heart disease. The expression of miRNA-101 was determined by quantitative real-time PCR in the right atrial appendages of patients with and without AF. The cell-specific localization of miRNA-101 was detected by in situ hybridization assay. The mRNA and protein expression levels of transforming growth factor β typeⅠreceptor (TGFβRⅠ) and collagen type I (COL1) were determined by quantitative real-time PCR and Western-blot assay, respectively. Collagen in the right atrial appendages was observed by Masson staining assay. Results The expression of miRNA-101 was found to be significantly down-regulated in AF patients compared with patients with sinus rhythm (SR) (P < 0.05). The result of miRNA-ISH showed that miRNA-101, which was highly distributed within the connective tissues of heart, was down-regulated at about 24.9% in patients with AF compared with patients with SR. No significant differences at the mRNA expression level of TGFβRI was found between patients with AF and patients with SR (P > 0.05). But the protein expression of TGFβRI in patients with AF was significantly higher than that of patients with SR (P < 0.05). The mRNA and protein expressionsl of COL1 were significantly higher in patients with AF than thoset of patients with SR (P < 0.05). The collagen was significantly increased in patients with AF than that of patients with SR (P < 0.05). Conclusions Downregulation of miRNA-101 may contribute to atrial fibrosis in human atrial fibrillation by targeting TGFβRⅠ.

Objective:To explore the effect of endothelin-1 on atrial ifbrosis in patients with atrial ifbrillation (AF).
Methods: A total of 72 patients with thoracotomy were studied, the patients were divided into 2 groups:AF group, n=39 and Sinus rhythm (SR) group, n=33. The mRNA and protein expressions of endothelin-1 (ET-1), platelet derived growth factor-B (PDGF-B) and collagen I (COL1) in right atrial appendage (RAA) tissue were measured by RT-PCR and Western blot analysis;meanwhile, the impact of ET-1 stimulation and non-selective ET-1 receptor antagonist (sulfafurazole SIZ) on PDGF-B mRNA and protein expressions in H9c2 cells were measured.
Results: ①The RAA tissue mRNA and protein expressions in AF group were higher than those in SR group, as for ET-1 (2.830 ± 2.276) vs (1.220 ± 0.887) and (0.835 ± 0.241) vs (0.286 ± 0.083), both P<0.01;for PDGF-B (2.568 ± 2.348) vs (1.567 ± 0.831) and (0.807±0.241) vs (0.381 ± 0.105), both P<0.05;for COL1α1 (3.376 ± 1.598) vs (1.629 ± 0.833) and (0.652 ± 0.210) vs (0.312 ± 0.12), both P<0.05.②The protein expressions of ET-1 and COL1 had positive correlation (r=0.580, P<0.01).③ET-1 promoted PDGF-B secretion in H9c2 cells in a concentration and time-dependent manner;SIZ could reduce such promotion.
Conclusion: ET-1 plays an important role in AF occurrence which might be related to PDGF-B regulation.

Aim To investigate the roles of Cx43 in mitochondria and mitochondrial ATP sensitive potassium channe1(mitoK_(ATP)~+)participating in the protection for heptanol preconditioning on myocardial ischemia/reperfusion injury of rabbits.Methods In anesthetized open-chest rabbits,the left anterior descending artery(LAD)was occluded for 30 min and reperfused for 4 hrs.All rabbits were randomly divided into five groups(n=16 in each group):sham operation group(Group Sham),ischemic reperfusion group(Group IR),ischemic preconditioning group(Group IP),heptanol preconditioning group(Group HT)and 5-HD plus heptanol preconditioning group(Group HT+5-HD),All rabbits in the five groups were killed 4h after reperfusion.Myocardial infarct size was determined at the end of the experiment.The heart rate and the mean arterial pressure(MAP)were recorded and plasma CK-MB and cTnI activity were measured at baseline,the end of ischemia,and after 2 hrs and 4 hrs of reperfusion respectively.Mitochondria was isolated with different centrifugations.Ultrastructural changes of mitochondria were observed under electron microscope.The content of the mitochondria Cx43 was detected with Western blot.Results The plasma CK-MB,cTnI activity and myocardial infarct size were significantly reduced in IP(18.97±2.8)% and HT(19.97±3.8)% groups as compared to IR groups (35.67±5.8)%,(P<0.01).Compared to group IR,the damage of mitochondria in group IP and group HT were milder(P<0.01).No significant difference was found between Group IP and Group HT.Compared to sham group, the mitochondria Cx43 expression was distinctly decreased in group IR and group HT+5-HD(P<0.01)and no significant difference was found between Group IP and Group HT.Conclusions Heptanol preconditioning can protect the heart from I/R injury by improving mitochondrial ultrastructure and by attenuating the decrease of mitochondria Cx43 expression induced by I/R.The mitochondrial Cx43 expression may be concerned with depending on mito K_(ATP)~+.

BACKGROUND:Cell transplantation can repair damaged myocardial tissue.However,whether transplaned cells and host cells formed an effective electricity and mechanical couple or whether reconstruction of connexin (Cx) and arrhythmia formed,are still unclear.OBJECTIVE:It is hypothesized that arrhythmia can be treated by changing Cx levels and intervening abnormal GJ channel.Moreover,to explore the effects of bone marrow mesenchyma stem cells (MSCs) on the expression of Cx43 and Cx45 in rata with myocardial infarction.DESIGN,TIME AND SETTING:The randomized controlled animal study was performed at the Experimental Center,Guangxi Medical University from January 2008 to May 2009.MATERIALS:A total of 180 Wistar rats were randomly divided into four groups:normal control,sham operation,myocardial infarction,and MSCs,with 45 animals in each group.Each group was then divided into 3 subgroups (n=15) according to 4 weeks,8 weeks and 12 weeks post-transplantation.Additional 20 healthy,Wistar rats,aged 1 month,were selected to harvest MSCs.METHODS:The third passage of MSCs was induced by 5-aza like cardiomyocytes for 4 weeks,labeled with DAPI at 2 hours before transplantation.Models of acute myocardial infarction were established in all groups except sham operation group.At day 7 after model preparation,2×10~(10) /L MSCs were infused into the edge and center of myocardial infarcted region by multipoint injection.Rats in the myocardial infarction group were subjected to an equal volume of saline as wall as those in the normal control and sham operation groups.MAIN OUTCOME MEASURES:The mRNA expressions of Cx43,Cx45 were assayed by fluorescence quantitative PCR.RESULTS:The mRNA expression of Cx43 among each groups had no difference at weeks 4,8 and 12 after intervention in the normal areas.Compared to the normal areas,Cx43 mRNA reduced significantly at ischamic zone in the myocardial infarction group and MSCs group (P＜0.01),with notably increased of Cx45 mRNA expression (P＜0.01).Compared to myocardial infarction group,Cx43 mRNA expression was statistically higher in the MSCs group at the same points (P ＜ 0.01),and the Cx45 mRNA dramatically declined (P ＜ 0.01).CONCLUSION:Acute myocardial infarction reduces the mRNA expression of Cx43 and increases the Cx45 mRNA expression.The exogenous cells transplantation can upturn the mRNA expression of Cx43 in the border-zone of the infarcted area,and down-regulate the Cx45 mRNA expression in the border-zone of the infarcted area.

BACKGROUND: Stem cell transplantation in repairing infarct myocardium and in improving cardiac function has been widely accepted. However, whether transplanted cells and host cells formed an effective electricity and mechanical couple, whether a relevant independent electrical system with contractile function formed or whether severe malignant ventricular arrhythmia formed, are still unclear.OBJECTIVE: To investigate electrophysiological abnormaltiy and left ventricular remodeling in rats with myocardial infarction following allogenic bone marrow mesenchymal stem cell (BMSC) transplantation.DESIGN, TIME AND SETTING: The randomized controlled animal study was performed at the Experimental Center, Guangxi Medical University from December 2005 to October 2008.MATERIALS: A total of 120 healthy Wistar rats were equally randomized into normal control, sham operation, saline control and cell transplantation groups. Healthy Wister rats aged 1 month were selected to harvest bone marrow.METHODS: At the third passage, rat BMSCs were collected and treated with 5-aza, and differentiated into cerdiomyocytes.BMSCs were labeled with DAPI at 2 hours before transplantation. In the saline control and cell transplantation groups, rat models of myocardial infarction were established by ligating the left anterior descending coronary artery. In the sham operation group, the coronary artery was not ligated, but only braid. At 7 days following ligation, BMSCs in the cell transplantation group at 2×10-1/L were infused into the edge and center of myocardial infarct region by multipoint injection. Rats in the other three groups were subjected to an equal volume of saline.MAIN OUTCOME MEASURES: Electrocardiogram and cardiac electrophysiology were performed. Ultrasonic cardiography was used to detect left ventricular function. Infarct size was determined. DAPl-labeled donor cell migration and distribution was observed with a fluorescence microscope.RESULTS: BMSCs could differentiate into cardiacmuscle cell-like cells which were capable of pulsing spontaneously, expressing cardiactoponin T and forming myofilament in vitro. Compared with the saline control group, PR interval, QRS duration and ventdcular effective refractory period shortened, ventricular fibrillation threshold increased at 4, 8 and 12 weeks (P < 0.05); left ventricular internal diameter at end-systole reduced, and left ventricular ejection fraction and shortening traction was significantly increased (P< 0.05). At 8 and 12 weeks, infarct size was significantly smaller (P < 0.05). At 4 weeks, DAPl-labeled BMSCs could be seen under the fluorescence microscope, and still could he detected at 12 weeks. However, the fluorescence became weak with prolonged time.CONCLUSION: BMSCs have the plasticity of differentiating into cardiac muscle cell-like cells, which can modulate theelectrophysiological abnormality and left ventricular remodeling following myocardial infarction.