Showing papers by "Feng Zhang published in 2006"

Channelrhodopsin-2 and optical control of excitable cells

Abstract: Electrically excitable cells are important in the normal functioning and in the pathophysiology of many biological processes. These cells are typically embedded in dense, heterogeneous tissues, rendering them difficult to target selectively with conventional electrical stimulation methods. The algal protein Channelrhodopsin-2 offers a new and promising solution by permitting minimally invasive, genetically targeted and temporally precise photostimulation. Here we explore technological issues relevant to the temporal precision, spatial targeting and physiological implementation of ChR2, in the context of other photostimulation approaches to optical control of excitable cells.

Genetic association between schizophrenia and the DISC1 gene in the Scottish population

Abstract: Several lines of evidence support the involvement of the disrupted in schizophrenia 1 (DISC1) gene in schizophrenia susceptibility, including its original identification in a schizophrenia family with a chromosome translocation, several genetic association studies, and functional characterization of the gene product. In the present study, we have genotyped multiple SNP and microsatellite markers in a large Scottish case-control sample. We identified two SNPs and one microsatellite that show significant association with schizophrenia. The strongest association is with a haplotype of SNPs rs751229 and rs3738401, located at the 5′ end of the gene; the C-A haplotype of these SNPs is associated with a relative risk of schizophrenia of 5 in our population. We also observe association with a microsatellite in intron 7, but no association with markers toward the 3′ end of the gene. The results are in broad agreement with those of other genetic studies, but there are differences in terms of the precise patterns of association. This analysis further strengthens the candidacy of DISC1 as a risk factor for schizophrenia in the general population, and suggests that more intensive searching for causative variants is justified. © 2006 Wiley-Liss, Inc.

Long term follow-up on emergent intracoronary autologous bone marrow mononuclear cell transplantation for acute inferior-wall myocardial infarction

Abstract: OBJECTIVE To investigate the effects of emergent intracoronary autologous bone marrow mononuclear cell (BM-MNC) transplantation on left ventricular function and myocardium lesion area in patients with first acute inferior-wall myocardial infarction. METHODS Forty patients with first onset of acute inferior-wall myocardial infarction, 28 males and 12 females, aged < or = 75, treated with emergent percutaneous coronary intervention (PCI) were randomly divided into 2 equal groups: group undergoing intracoronary transplantation of autologous BM-MNC via a micro-catheter right after PCI (BM-MNC group), and control group receiving normal saline and heparin. Blood routine examination, myocardium zymogram, and serum high sensitive C reactive protein (hsCRP) were detected, and 24-hour dynamic electrocardiography, delayed-enhancement myocardial magnetic resonance imaging (CMR), and angiography of the coronary artery and left ventricle were conducted before the transplantation and immediately, 1 week, and 6 months after transplantation. RESULTS CMR showed that 6 months later the left ventricular ejection fraction (LVEF) of the control group was 47.9% +/- 6.7%, significantly higher than that 1 week later (43.4% +/- 6.7%, P = 0.001), and the LVEF of the BM-MNC group 6 months later was 51.5% +/- 5.2%, significantly higher than that 1 week later (44.5% +/- 7.1%, P = 0.001; however, the absolute change of LVEF (DeltaLVEF) of the BM-MNC group was 6.95% +/- 3.33%, significantly higher than that of the control group (4.05% +/- 1.68%, P = 0.047). Six months later the myocardial lesion area of the BM-MNC group decreased more significantly in comparison with the control group. Nevertheless, there was no difference in change of left ventricular end diastolic volume (LVEDV) between these two groups. The serum hsCRP 48 h after transplantation of the BM-MNC group was 2.8 g/L +/- 0.8 g/L, significantly lower than that before transplantation (13.4 g/L +/- 3.6 g/L, P < 0.001). No severe clinical events, such death, recurrent cardiac infarction, malignant arrhythmia, occur in these 2 groups. CONCLUSION Emergent intracoronary transplantation of autologous BM-MNC in patients with acute inferior-wall myocardial infarction improves the left ventricular function and myocardial infusion, minimizes the myocardial lesion area significantly.

Early experiences on living donor liver transplantation in China: multicenter report.

Abstract: Background Because of the lack of brain death laws in China, the proportion of cadaveric organ donation is low. Many patients with end-stage liver disease die waiting for a suitable donor. Living donor liver transplantation (LDLT) would reduce the current discrepancy between the number of patients on the transplant waiting list and the number of available organ donors. We describe the early experience of LDLT in the mainland of China based on data from five liver transplant centers. Methods Between January 2001 and October 2003, 45 patients with end-stage liver disease received LDLT at five centers in China. The indication and timing, surgical techniques and complications, nonsurgical issues including rejection, infection, and advantages of LDLT in the series were reviewed. Actuarial patient and graft survival rates were calculated by using the Kaplan-Meier product-limit estimate. Statistical analysis was completed by using SPSS 10.0. Results All LDLT recipients were cirrhotic patients, except for one man with fulminant hepatic failure. Among the 45 cases of LDLT, 35 (77.8%) were performed in one center (the First Affiliated Hospital of Nanjing Medical University). The overall 1 and 3 year survival rate of the recipients was 93.1% and 92.0%, respectively. Of the 45 LDLT donors, there were 3 cases of biliary leakage, 2 subphrenic collections, 1 fat liquefaction around the incision and 1 biliary peritonitis after T tube removal. All donors recovered completely. Conclusions LDLT provides an excellent approach to addressing the problem of donor shortage in China even though the operation is complicated, uncompromising and difficult with respect to the safety of the donors and receptors. Despite early technical hurdles having been overcome, perfection of technique is still necessarily. At present, LDLT is a good choice for the patients with irreversible liver disease.

Gene conversion between direct noncoding repeats promotes genetic and phenotypic diversity at a regulatory locus of Zea mays (L.)

Abstract: While evolution of coding sequences has been intensively studied, diversification of noncoding regulatory regions remains poorly understood. In this study, we investigated the molecular evolution of an enhancer region located 5 kb upstream of the transcription start site of the maize pericarp color1 (p1) gene. The p1 gene encodes an R2R3 Myb-like transcription factor that regulates the flavonoid biosynthetic pathway in maize floral organs. Distinct p1 alleles exhibit organ-specific expression patterns on kernel pericarp and cob glumes. A cob glume-specific regulatory region has been identified in the distal enhancer. Further characterization of 6 single-copy p1 alleles, including P1-rr (red pericarp/red cob) and P1-rw (red pericarp and white cob), reveals 3 distinct enhancer types. Sequence variations in the enhancer are correlated with the p1 gene expression patterns in cob glume. Structural comparisons and phylogenetic analyses suggest that evolution of the enhancer region is likely driven by gene conversion between long direct noncoding repeats (approximately 6 kb in length). Given that tandem and segmental duplications are common in both animal and plant genomes, our studies suggest that recombination between noncoding duplicated sequences could play an important role in creating genetic and phenotypic variations.

[Surgical methods in living donor liver transplantation: with report of 50 cases].

Abstract: OBJECTIVE To investigate and evaluate different surgical methods applied in living-donor liver transplantation (LDLT). METHODS Fifty patients with end-stage liver disease received LDLT in our department between January 1995 and March 2006. The data were analyzed on a retrospective basis. The choice of different surgical methods, strategies applied to ensure the safety of donors and indications of LDLT in the series were reviewed. RESULTS All donors recovered uneventfully. Among the 50 patients, 47 recipients presented with end-stage cirrhosis, 3 patients suffered from malignant tumor. To date, 6 recipients died after LDLT, among them, 3 recipients died of the operation and the other 3 recipients died of long-term complications. Resected donor livers included 9 cases of segments V, VI, VII and VIII (not including the middle hepatic veins) and 1 case of segments V, VI, VII and VIII (including the middle hepatic veins), 36 cases of segments II, III and IV (including the middle hepatic veins) and 4 cases of segments II, III, and part of IV (not including middle hepatic veins). CONCLUSIONS LDLT helps tackle the problem of donor shortage in the world. The process is complicated, and it is very important to choose appropriate surgical methods for the improvement of surgical achievement and donor safety.

[Living related liver transplantation for Wilson's disease: clinical study of 32 cases].

Abstract: OBJECTIVE: To summarize the experience in donor selection and surgical outcomes of living related liver transplantation (LRLT) for Wilson's disease (WD). METHODS: Thirty-two WD patients, 29 children and 3 being over 14, underwent LRLT because of chronic advanced liver disease (29 cases) or fulminant hepatic failure (3 cases) among which 13 cases showed neurological dysfunction. The donors, including 7 fathers and 25 mothers, had their serum ceruloplasmin levels within normal limit or slightly lower and their 24-hour urine copper < 100 microg. The modes of operation included orthotopic partial liver transplantation (31 cases) and orthotopic accessory partial liver transplantation (1 case). The patients were followed p for 3-63 months postoperatively. RESULTS: Two patients die in the intraoperative period, and 2 died of bile leakage and severe rejection combined with infection. Twenty-eight patients survived, of which 2 had hepatic artery thrombosis and underwent retransplantation of cadaveric liver, one had anatomic stenosis 8 months after the original transplantation and underwent Roux-en-Y hepaticojejunostomy, 2 had chronic rejection 22 and 28 months after the LRLT respectively and were successfully rescued by switching their primary immunosuppressor from cyclosporine A to FK506. Eleven patients with neurological dysfunctions all showed long-term survival and their extrapyramidal signs and speech disorders, and dyskinesia all were alleviated. CONCLUSION: LRLT is the treatment of choice for WD patients with chronic advanced liver disease and fulminant hepatic failure. After LRLT the disorders of the nervous system are alleviated.