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Biomedical subjects

Ju Mei

Publications and source records attributed to Ju Mei.

10 recordsLinked to original sources
PubMed2006

[Experimental studies on tissue engineered esophagus reconstructed with artificial biodegradable scaffold].

OBJECTIVE: To verify adhesion and growth ability of canine esophageal epithelial cells (EECs) on the poly (lactic-co-glycolic acid) (PLGA), a three-dimensional biodegradable polymer scaffold, and to reconstruct the canine esophagus by the tissue engineering. METHODS: Free canine EECs isolated from adult dogs by esophagoscopy were seeded onto the PLGA scaffolds precoated with collagen type IV after the first passage by the in vitro culture. Then, the composites of the cell-scaffold were respectively cultured in vitro and in the abdominal cavity of the dog in vivo. After different periods, the cell-seeded scaffolds were assessed by histological HE staining, scanning electron microscopy, and immunohistochemical analysis. RESULTS: The cells displayed a cobblestone-shaped morphology that was characteristic of the epithelial cells and were stained to be positive for cytokeratin, which indicated that the cells were EECs. The canine EECs were well distributed and adhered to the PLGA scaffolds, and maintained their characteristics throughout the culture period. After the culture in vivo for 4 weeks, the cell-seeded scaffolds looked like tissues. CONCLUSION: PLGA scaffolds precoated with collagen type IV can be suitable for adhesion and proliferation of EECs, and can be used as a suitable tissue engineering carrier of an artificial esophagus.

Absorbable Implants↗
PubMed2005

[Study of adenovirus-mediated vascular endothelial growth factor 165 gene transfer into bone marrow stromal cells and its expressive product promoting proliferation of endothelial cells].

OBJECTIVE: To study transcription, expression, and bioactivity of expressive protein of vascular endothelial growth factor 165 (VEGF(165)) gene, after bone marrow stromal cells (BMSCs) were transferred by VEGF(165) gene mediated by adenovirus vector ex vivo. METHODS: BMSCs were Isolated and cultured by gradient centrifugation method. The cells cultured are transferred by recombinant adenovirus vector that carry VEGF(165) gene. Transcription and expression of VEGF(165) gene in BMSCs and secretion of VEGF protein in culture medium were measured by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and enzyme linked immunosorbent assay (ELISA) methods. The activity of VEGF protein in culture media was detected by proliferation effects on vascular endothelial cells. RESULTS: When Ad. VEGF(165) transferred into BMSCs, there was an effective transcription and expression. The expressed product in the media of transferred cells had highly biological activity on proliferation of rat aortic vascular endothelial cells (P < 0.01). CONCLUSIONS: Adenovirus vector can be transferred into BMSCs efficiently and safely. Adenovirus mediated VEGF(165) gene transferred into BMSCs could express VEGF protein with highly biological activity, which provided foundation on BMSCs based gene therapy for ischemic disease.

Adenoviridae↗
PubMed2004

[Surgical interventions for complex native valve endocarditis].

OBJECTIVE: To elucidate the early and long-term results of surgical treatment for complex infective endocarditis with prosthetic valve replacement. METHODS: Fifty-seven patients of complex native valve endocarditis, including 25 cases of aortic valve, 16 of mitral valve and 16 of double valves, who underwent operative interventions with prosthetic valve replacement between December 1988 and June 2002, were analyzed retrospectively. Intraoperative findings demonstrated aortic annular abscesses (n = 19), root abscesses (n = 4), mitral posterior annular abscesses (n = 11), myocardial abscesses (n = 6), massive leaflet destruction (n = 32) and valvular vegetations (n = 55). Complex reconstruction of the aortic and mitral annulus was required in 35 patients. Associated procedures included Bentall's procedure (n = 4), aortic valve replacement (n = 21), mitral valve replacement (n = 16) and double valve replacements (n = 16). RESULTS: The operative mortality was 11%. Complications included low cardiac output syndrome, recurrence of endocarditis, multiple organ failure, ventricular arrhythmia, bleeding, mediastinal infection, respiratory insufficiency and heart block. Follow-up was 100% complete at a mean of 5.93 years. There were five late deaths (3 prosthetic valve endocarditis, 2 valve-related). The NYHA functional status recovered to Class I in 17 patients, Class II in 27 and Class III in 2 at 1 year follow-up. Kaplan-Meier analysis showed the 5-year actuarial freedom from reoperation was (84 +/- 3)%, and actuarial survivorship at 5 years was (61 +/- 9)%. CONCLUSIONS: Urgent or even emergency operation is advocated for complex infective endocarditis. Proper intraoperative reconstruction of the aortic and mitral annulus and optimized perioperative management, especially the strategy for prevention of recurrent endocarditis, are of great importance in achieving satisfied early and long-term clinical outcomes.

Adolescent↗
PubMed2003

[Induction of angiogenesis in ischemic myocardium by adenovirus mediated angiopoietin-1 gene transfer, an experimental study].

OBJECTIVE: To investigate the effect on angiogenesis in ischemic myocardium of adenovirus mediated angiopoietin-1 gene transfer. METHODS: Ang-1 cDNA was obtained from human spleen by RT-PCR and then cotransfected into 293 host cells together with Adv5-CAG, E1 and E3 substituted adenovirus genome, thus constructing recombinant adenovirus Adv5-CAG/Ang-1. Recombinant adenovirus Adv5-CAG/LacZ containing LacZ gene was constructed too. Thirty six male New Zealand white rabbits were randomly divided into 3 group of 12 rabbits: DMEM group, Ang-1 group, and LacZ group and underwent high-positioned double-ligation of the left anterior descending coronary artery and then myocardial injection of DMEM, Adv5-CAG/Ang-1, or Adv5-CAG/LacZ respectively. Fourteen days after the operation 2 rabbits in each group were killed, the myocardial tissues where injected was given were taken to detect the expression of Ang-1 by RT-PCR. Coronary angiography was conducted 28 days postoperatively upon 5 rabbits in each group to observe the angiogenesis in the ischemic myocardium. Five rabbits in each group were killed at the 14 th and 28 th postoperative days to observe the capillary density by immunohistochemical staining. RESULTS: The Ang-1 cDNA cloned in the laboratory was 1,515 bp in length containing the signal peptide structure in accordance with the report in literature. Fourteen days after operation, Ang-1 gene was positive in the myocardium of Ang-1 group and negative in the other 2 groups. New vessel formation was obvious at the 28 th postoperative day in the Ang-1 group and not in the other 2 groups. Capillary density increased after operation in all 3 groups, however, more significant in the Ang-1 group, especially 28 days after. CONCLUSION: Adenovirus-mediated angiopoietin-1 gene effectively promotes the neovascularization in ischemic myocardium of rabbits.

Angiogenesis Inducing Agents↗
PubMed2003

[Congenital coronary artery fistulae in adults: diagnosis and surgical treatment].

OBJECTIVE: To summarize the clinical characteristics, diagnosis and surgical in-treatment results of congenital coronary artery fistulas (CAF) in adults. METHODS: Fourteen patients (8 men, 6 women), aged from 18 to 60 years with a mean of 32 +/- 13 years, underwent surgical correction of CAF between March 1985 and April 2002. Eleven of the 14 patients (78.57%) were symptomatic. The diagnosis of CAF was made by echocardiography or angiocardiography preoperatively. The fistulae originated from the right, left and double coronary arteries in 10 (71%), 3 (21%) and 1 (7%) patient(s), respectively. The fistulae drained into the right ventricle (8 patients), left ventricle (4), right atrium (1) and pulmonary artery (1), respectively. The diameter of fistulae ranged from 0.30 to 1.80 cm with a mean of (1.16 +/- 0.49) cm. There were 6 CAF patients associated with coronary artery aneurysms and 4 CAF patients with other coexisting cardiac defects. The distal fistulae were closed in 10 patients with cardiopulmonary bypass (CPB) and 4 patients without CPB. The coexisting defects were corrected simultaneously. RESULTS: There was no early and late death. One patient had low cardiac output syndrome and cured during early postoperative period. Twelve patients (85.71%) were followed up for a mean period of 3.35 +/- 4.28 years without myocardial ischemia or infarction and recurrent fistulae. Heart function was improved to NYHA functional class I in 11 patients and class II in 1 patient. CONCLUSIONS: All adult patients with CAF who have demonstrable hemodynamic and cardiovascular morphological changes should be surgically treated as early as possible. The appropriate surgical management and reliable myocardial protection are key points of good surgical results.

Adolescent↗
PubMed2003

[Long-term results of mitral-aortic valve replacement in 1,154 patients with rheumatic valvular disease].

OBJECTIVE: To analyze the early and long-term results after mitral-aortic valve replacement for rheumatic valvular disease and the determinant factors involved and subsequent therapies. METHODS: 1 154 patients receiving combined mitral-aortic valve replacement for rheumatic valvular disease from May 1981 to May 2001 were reviewed. The mean age of the patients was 41.48 +/- 10.00 years. Concomitant valve plasty was performed for associated tricuspid organic or significant functional lesions. Lateral tilting disc or bileaflet valve prostheses were used for replacement. New York Heart Association functional status showed Class III or IV in 91.77% of the patients. Moderate to severe pulmonary hypertension occurred in 29.38% of the patients. The duration of follow-up varied from 8 months to 20 years. RESULTS: The hospital mortality was decreased from 6.50% to 4.45%. The 5-, 10- and l5-year survival rates were 89.46% +/- 1.35%, 86.50% +/- l.91% and 67.86% +/- 6.16%, respectively. The 5-, 10- and l5-year thromboembolic event free rates were 97.80% +/- 0.74%, 88.31% +/- 2.20% and 94.08% +/- 2.29%, respectively. the 5-, 10- and l5-year anticoagulant related bleeding free rates were 94.80% +/- 1.09%, 89.32% +/- 2.10% and 83.12% +/- 3.57% respectively. Cardiac functional status returned to Class II in 98% patients and to Class III in 2% during follow-up. CONCLUSIONS: Both left and right ventricular functions may be impaired as a result of rheumatic valvular disease. Tricuspid valve should be explored during surgery and any significant tricuspid annular enlargement and regurgitation showed be corrected in concomitance. Long-acting penicillin regimen is needed for 3 - 5 years for the prevention of rheumatic fever relapse. A low intensity anticoagulant regimen after valve replacement with prothrombin time targeting at 1.5 - 2.0 times is advisable in lessening anticoagulant related bleeding yet optimizing sufficient prevention against thromboembolic complications.

Adolescent↗
PubMed2003

[Long-term results of prosthetic mitral valve replacement with home-made tilting disc valve: a report of 125 cases].

OBJECTIVE: To analyze the early and long-term results after mitral valve replacement for rheumatic valvular disease by using home-made tilting disc valve, and the determinant factors involved and subsequent therapies. METHODS: One hundred and five patients, including 31 patients with rheumatic mitral stenosis, 92 patients with mixed mitral stenosis and regurgitation, and 2 patients with bacterial endocarditis, underwent prosthetic mitral valve replacement with home-made tilting disc valve from September 1978 to June 1982. Three patients had a history of mitral commissurotomy, and 5 patients had concomitant functional tricuspid regurgitation. All patients were operated on under cardiopulmonary bypass with implantation of 25 - 29 mm size home-made tilting disc valve prosthesis. The associated functional tricuspid lesions were treated at the same time with modified DeVega's valvuloplasty or Kays bicuspidate valvuloplasty. RESULTS: Eleven patients died during the hospital stay with an early operative mortality of 8.8%. The major causes of the early death were low cardiac output syndrome (4 patients), respiratory failure (2), acute renal failure (2), extrinsic prosthesis dysfunction (1), ventricular arrhythmia (1), and left ventricular rupture (1). Ninety-eight survivors were followed up (total 1,162.2 years) for mean duration of 12.8 years. Eighty-nine patients (78%) survived over 10 years after operation, 58 (51%) over 15 years, and 55 (48%) over 20 years. There were 16 late deaths due to heart failure, anticoagulation related bleeding, thromboembolism and recurrence of rheumatic fever. The survival rates at 10 and 20 years were 82.3% and 51.1% respectively. Among the patients who survived over 20 years, 37 patients had the cardiac functional status returned to Class II, 13 Class III, and Class IV. CONCLUSIONS: Severe post-rheumatic valve deformity may occur in younger patients in China. Long-acting penicillin regimen given for 3 - 5 years for the prevention of rheumatic fever relapse is advocated. A low intensity anticoagulant regimen after mitral valve replacement is advisable in lowering the incidence of anticoagulant related bleeding, while optimizing sufficient protection against thromboembolic complication. Proper operative timing (e.g. when the patient is in sinus rhythm and in NYHA functional class II) is of great importance in achieving satisfied long-term results.

Adolescent↗
PubMed2002

[Cell transplantation of 5-aza cytidine induced bone marrow stromal cells transfected by angiogenin gene ex vivo into infarcted myocardium, an experimental study].

OBJECTIVE: To investigate the effect of transfection of 5-aza cytidine (5-aza) induced BMSCs that were transfected with Ad. ANG ex vivo into infarcted myocardium. METHODS: Lewis rat BMSCs were cultured in vitro and incubated together with 5-aza (3 micro mol/l) for 24 hours, and the induced BMSCs were transfected with Ad. ANG with a infection multiple of 50. ELISA method was applied to assay the expression and secretion of ANG in the medium. Then such BMSCs expressing ANG were transplanted into the ischemic myocardium of 14 Lewis rats whose left descending branch of coronary artery had been ligated 4 weeks ago (Group I). Eight rats with infarcted myocardium were transplanted with such BMSCs too (group II). Another eight rats received only Ad. ANG injection (group III). Twelve rats receiving serum-free medium injection were used as controls (Group IV). Four weeks after the ligation of LDA (for group I) and 4 weeks after the beginning of experiment (for all groups), the parameters of heart function, such as ejection fraction (EF) and end-diastole volume of left heart (EDLV), were examined by echocardiography. Four weeks after the beginning of experiment, the rats were killed, and the survival and differentiation of transplanted BMSCs and angiogenesis were observed by immunohistochemistry and transmission electron micrography. RESULTS: One day after the beginning of experiment, the concentration of ANG in the supernatant of medium was 162 +/- 10 pg/ml, significantly higher than that in the supernatant of medium in control group (86 +/- 5 pg/ml, P < 0.01). The concentration of ANG gradually increased and reached its peak at the 4th to 7th day; ANG could still be assayed 15 days later. 4 weeks after the transplantation, most of the 5-aza-induced BMSCs in group I and group II had differentiated into cardiomyogenic cells in the transplanted area. The EF value was 0.42 +/- 0.114 weeks after ligation of LAD, and was 0.69 +/- 0.034 weeks after the transplantation in group I. The EF value was 0.46 +/- 0.06 at the beginning of experiment and was 0.64 +/- 0.144 weeks after the transplantation in group II. The improvement of EF in Group I was significantly than that in other 3 groups (P < 0.05 or P < 0.01). The number of new vessels in group I was 36.3/high-power field (HPF), significantly higher than those in the other three groups (10.5/HPF in Group II, 23.1/HPF in Group III, and 0.9/HPF in Group IV). CONCLUSION: Induced by 5-aza, BMSCs differentiate into cardiomyogenic cells in infracted myocardium. ANG-expressing BMSCs transplantation is one of the safe and beneficial new strategies for repairing damaged myocardium and enhancing angiogenesis in ischemic myocardium.

Animals↗
PubMed2002

[Giant left atrium combined with mitral valvular disease: morphologic classification and its clinical significance].

OBJECTIVE: To study the morphologic classification and its clinical significance of giant left atrium (GLA) combined with mitral valvular disease. METHODS: Between 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. RESULTS: According 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. CONCLUSION: The 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↗