Biomedical subjects

Zhi-Yun Xu

Publications and source records attributed to Zhi-Yun Xu.

3 recordsLinked to original sources

PubMed2006

Transplantation of angiogenin-overexpressing mesenchymal stem cells synergistically augments cardiac function in a porcine model of chronic ischemia.

OBJECTIVE: Accumulated evidence suggests that myogenesis and angiogenesis induced by implanted cells play important roles in restoring cardiac function after a myocardial infarction. The current study investigated the effects of transplanted autologous mesenchymal stem cells overexpressing angiogenin on myocardial perfusion and cardiac function in the porcine chronic ischemic model. METHODS: Chronic ischemia was generated in Yorkshire pigs by placing an ameroid constrictor around the left circumflex artery. Four weeks after occlusion, the animals were randomly separated into 4 groups: pigs in the MSC(AdAng) or MSC(AdNull) groups were implanted with 6 x 10(8) mesenchymal stem cells infected with adenovirus containing angiogenin gene or null adenovirus, respectively; pigs in the AdAng or AdNull groups were injected intramyocardially with adenovirus (5 x 10(9) plaque forming unit/pig) containing angiogenin gene or null adenovirus, respectively. Four weeks after implantation, mesenchymal stem cells prelabeled with DiI were observed within the implanted area in both cell transplantation groups. RESULTS: Angiogenin protein levels were significantly greater in the MSC(AdAng) and AdAng groups than in the other 2 groups and were associated with greater neovessel formation than in the other 2 groups. Mesenchymal stem cell transplantation decreased scar size and increased scar thickness. Both the AdAng and MSC(AdNull) groups experienced improved cardiac function compared with that seen in the AdNull group. However, a synergistic effect of mesenchymal stem cells and angiogenin was observed in the MSC(AdAng) group because myocardial perfusion and cardiac function increased significantly (P < .05 for all groups) in this group compared with all the others. CONCLUSIONS: Transplantation of autologous mesenchymal stem cells transfected with the angiogenin gene revealed a synergistic effect on the improvement of heart perfusion and function after ameroid occlusion.

Animals↗

PubMed2005

Prognostic value of KIT mutation in gastrointestinal stromal tumors.

AIM: To examine the prevalence and prognostic significance of C-kit gene mutation and analysis the correlation of C-kit gene mutation and the clinicalpathologic parameters of GISTs. METHODS: Eighty-two GISTs were studied for the mutation of C-kit gene by PCR-SSCP, DNA sequence. Statistical comparison were used to analysis the correlation of C-kit gene mutation and clinicalpathology, clinical behavior, recurrence. RESULTS: (1) Mutation-positive and mutation-negative GISTs were 34 and 48,respectively; (2) Among these patients with C-kit mutation remained a significantly poor prognosis associated with 59% 3-year survival compared to those whose tumors did not; (3) Tumor size, PCNA index, mitotic cell number, presence of necrosis, microscopic invasion to adjacent tissues, recurrence and distant metastasis among mutation-positive and mutation-negative GISTs were significantly different. CONCLUSION: C-kit mutation is a undoubtedly pivotal event in GIST and may be associated with poor prognosis. Evaluation of C-kit gene mutation may have both prognosis and therapeutic significances.

Adult↗

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↗