BACKGROUND: Cell transplantation is a new technique to treat myocardial ischemic diseases in recent years. There are not many reports regarding smooth muscle cell(SMC) transplantation at moment.OBJECTIVE: To investigate the impact of autologous SMC transplantation on the survival and the restoration of cardiac function after myocardial infarct.DESIGN: An observatory comparative study based on experimental animals.SETTING: Institute of cardiothoracic surgery in a military medical university of Chinese PLA.MATERIALS: The study was conducted in the Institute of Cardiothoracic Surgery of the Second Military Medical University of Chinese PLA from January 2003 to June 2003. Totally 24 male adult SD rats in cleanness grade with a body mass of(300 ± 20) g were randomly divided into two groups,i. e. ,transplant group and control group with 12 rats each. All rats were fed in clean environment.METHODS: Autologous SMC was separated and extracted from the ductus deferens of SD rats by enzymic digestion for culture and amplification in vitro. BrdU-labeled autologous SMC was directly injected into the scarring tissues of cardiac infarct area induced by the ligation of anterior descending branch of left coronary artery 2 weeks ago in rats of transplant group. DMEM culture medium of same volume was injected into the rats of control group. Cardiac function was evaluated by ultrasound examination before and 4 weeks after transplantation. The survival of the transplanted SMC and its effect of vasoformation in myocardial scarring tissues were detected by immunohistochemical staining.soformation in myocardial scarring area after autologous SMC transplantation;after transplantation.RESULTS: Transplanted autologous SMC survived and formed muscle-like tissues in myocardial infarct area. Compared with control group, left ventricnlar end diastolic volume(LVEDV) of transplant group was significantly reduced( P < 0.01), left ventricular ejection fraction(LVEF) was significantly elevated( P < 0.01 ), and the vasoformation in myocardial scarring tissue was significant( P < 0.01 ).CONCLUSION: Autologous SMC transplantation can prevent ventricle enlargement after myocardial infarct, promote vasoformation in infarct area, and ameliorate cardiac function.

Objective To investigate the surgical technique and clinical outcomes of reconstruction of the annulus and the intervalvular fibrous body during valve replacements. Methods Fifty-nine patients underwent reconstruction of the annulus or the intervalvular fibrous body during the valve replacement. Indications for the operation were small aortic annulus which may cause patient/prosthesis mismatch in 43, active infective endocarditis with the abscess in the periannulus tissue in 13, extensive calcification of the aortic annulus in 2 and an active bleeding complication of the aortic root after aortic and mitral valve replacement in 1. The reconstruction was done with fresh autologous pericardium. Results The aortic clamping time in reconstruction of the intervalvular fibrous body with double valve replacement was longer than that of the regular double valve replacement. Four patients died in the perioperative period, giving an overall in- hospital mortality of 6.7%. Postoperative complication were: re-sternotomy for bleeding in 2, Ⅲ degree A-V block in 2, respiratory dysfunction in 2, and acute renal failure in 2. Patients were followed up for 6 months by echocardiography study, and no periannular leakage was found. Conclusion Reconstruction of the annulus is an effective technique for patients with a small aortic annulus, extensive calcification of the interventricular fibrous body and active infective endocarditis with abscess. Although the operative procedure is challenging and taking more time, the technique is safe and reproducible.

Objective The results of Aortic valve replacement (AVR). Combined with ascending aortic replacement(group A) or aortoplasty (group B) in patients with aortic valve disease and ascending aortic dilatation were analysed to assess the clinical outcomes and respective indications. Methods Among the two groups, the age, gender, NYHA class, types of aortic valve lesions and left ventricular ejection fraction were not different statically. The ascending aortic diameters in group A[(50.41 ±3.71) mm] and group B [(48.29±2.18) mm] were not statically different. Ascending aortic replacement was performed in Group A. A Dacron tube(diameter 28 ～ 30mm) was routinely wrapped around the ascending aorta after aortoplasty in group B. Results There was 1 postoperative death in group B, blood transfusion volume and postoperative complications were not stasticaly different in the two groups. Cardiopulmonary bypass time [(110.52 ± 27.51) min] and aortic across clumping time [(71.70 ± 17.13)min] in group A were significantly longer than that of group B [(97.31 ± 19.46) min,P=0. 004; (57.13 ±19.46) min, respectively. P=0.025]. Conclusion Aortic valve disease, especially bicuspid valve disease often combines with ascending aortic dilatation or aneurysm. In younger patients, ascending aorta should be actively treated surgically when the diameter is equal or more than 40mm. Aortoplasty with external reinforcement of a Dacron tube is simpler and safer than aortic replacement in patient without aortic atherosclerosis or ulceration, and large aneurysm.

BACKGROUND: Secretion of various neurotrophic factors by Schwann cells plays important roles in neural regeneration. However, the secretion capability is affected by many factors. To seek a feasible method for promoting nerve growth factor secretion by Schwann cells is a key of regeneraion following neurologic defect.OBJECTIVE: To explore the effects of methylprednisolone(solu-medrol) on the secreted function of Schwann cells of cultured rats.METHODS: Schwann cells were isolated and cultured by enzyme digestion method. Cell growth was observed under an inverted phase contrast microscope. Following passage, purity of some Schwann cells was identified using S-100 protein immunity. Other Schwann cells were regulated using cell counting plate into 1×10~9/L, and incubated in a 6-well culture plate (15 wells) for further incubation. Following 4 days of culture, different concentrations of solu-medrol (10~(-3), 10~(-4), 10~(-6), 10~(-8) mol/L) were administrated to the cell, while blank control group (1 well) was given no drug. 24, 48 and 72 hours after administration, reverse trancription-polymerase chain reaction (RT-PCR) was used in the detection of the levels of nerve growth factor mRNA.RESULTS AND CONCLUSION: Number of primarily cultured cells was significantly increased at day 7, and 80% cells were confluent. Subcultured cells were spindle-shaped, with 2 thin long processes, showing positive fluorescence staining. Fibroblasts were round or flat, showing negative reaction of fluorescence staining. Reserve transcription-polymerase chain reaction demonstrated that nerve growth factor number at 72 hours affected by 10~(-8) mol/L radiosone was increased compared with the blank control group and other concentrations and other time points (P < 0.05). Number of nerve growth factor was reduced following treatment of 10~(-3) mol/L radiosone compared with the blank control group and other concentrations (P < 0.05). These results suggested that high concentration of solu-medrol prohibits secreted function of Schwann's cells, but long time and low dosage solu-medrol promotes secreted function of Schwann's cells.

OBJECTIVETo study the morphologic classification and its clinical significance of giant left atrium (GLA) combined with mitral valvular disease.

METHODSBetween January 1993 and December 1999, a total of 62 consecutive patients with mitral valvular disease, whose preoperative left atrial endodiastolic volume index >/= 300 ml/m(2) or endosystolic diameter >/= 6.0 cm, were enrolled as research candidates. Morphologically, GLA was classified by Q Hierarchical cluster analysis according to the right or left side cardiothoracic ratio of the left atrium (r- or l-LATR) on an anteroposterior chest roentgenogram and the ratio of the distant diameter of the left main bronchus to the approximate diameter of the left main bronchus (LBDd/Dp) or to the trachea (LB/TR) on an left anterior oblique chest roentgenogram.

RESULTSAccording to r-LATR and l-LATR, the morphology of GLA was classified clinically into three types: type L (l-LATR >/= 0.6 and r-LATR < 0.58), type R (r-LATR >/= 0.58 and l-LATR < 0.6) and type B (r-LATR >/= 0.58 and l-LATR >/= 0.6). According to LBDd/Dp and LB/TR, GLA in type L and B was further classified into two subtypes, respectively: left posterior downward type (L(I) and B(I)), in which LBDd/Dp is equal or exceeds 0.38 or LB/TR is equal or exceeds 0.33, and left posterior upward type (L(II) and B(II)), in which LBDd/Dp is less than 0.38 or LB/TR less than 0.33.

CONCLUSIONThe morphologic classification of GLA may represent the main pathophysiological changes of GLA and might be a guideline for the selection of the optimal plication procedures of GLA in patients with valve diseases.

Adolescent ; Adult ; Cardiomegaly ; pathology ; Female ; Heart Atria ; pathology ; Humans ; Male ; Middle Aged ; Mitral Valve Insufficiency ; pathology ; Mitral Valve Stenosis ; pathology