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Biomedical subjects

Xiao Xu

Publications and source records attributed to Xiao Xu.

At least 55 records · Page 3Linked to original sources
PubMed2004

[Structural analysis of 22 full-length hepatitis B virus genomes isolated from patients with hepatocellular carcinoma].

OBJECTIVE: To study the characteristics of full-length Hepatitis B Virus (HBV) genomes isolated from patients with hepatocellular carcinoma (HCC). METHODS: The full-length HBV genomes from the serum of HBsAg positive HCC patients were amplified by PCR, and then sequenced and analyzed its structure. RESULTS: Twenty-two full-length HBV DNAs were obtained from different patients of HCC. Phylogenetic analysis revealed that all HBV strains could be categorized into genotype B or C and serotype adr or adw2. Structural analysis showed that HBV obtained shared meaningful consensus mutations in B/T cell epitopes of surface and core antigens, transactivating domain of X protein and enhancer II/core promoter regions as compared to standard strains. CONCLUSION: Genotype and gene mutation of HBV may be closely correlated with the carcinogenesis of HBV-related hepatocellular carcinoma.

Amino Acids↗
PubMed2004

Orthotopic liver transplantation for patients with hepatocellular carcinoma complicated by portal vein tumor thrombi.

BACKGROUND: Orthotopic liver transplantation (OLT) has been the valuable treatment of choice for patients with hepatocellular carcinoma (HCC). As the number of patients with portal vein tumor thrombi (PVTT) increases, most transplant centers become suspicious of the exact effect of the operation which has been accepted as a radical method. This study was designed to evaluate the clinical effects of OLT for patients with HCC associated with PVTT. METHODS: The follow-up of 24 patients with HCC complicated by PVTT who had received OLT (transplant group) from January 1999 to March 2003 was compared to that of 27 patients undergoing routine hepatic resection (resection group) and 59 patients without surgical treatment (non-surgical group). RESULTS: The perioperative mortality was zero for the transplant group. The 6-month, 1-year, and 2-year overall survival rates were 66.7%, 29.5% and 23.6% for the transplant group, 33.3%, 22.2% and 14.8% for the resection group (P=0.0335), and 42.1%, 24.4% and 4.1% for the non-surgical group, respectively (P=0.0316). The tumor free survival rates of recipients at 6-month, 1-year, and 2-year were 51.5%, 23.2% and zero, respectively. During the period of follow-up, the overall post-transplant intrahepatic recurrence or extrahepatic metastasis rate was 66.7% for the transplant group. CONCLUSION: OLT is an effective but palliative treatment modality for patients with HCC associated with PVTT followed by a prolonged survival but a poor tumor free survival rate.

Budd-Chiari Syndrome↗
PubMed2004

Clinical experience in diagnosis and treatment of glucagonoma syndrome.

BACKGROUND: Pancreatic endocrine tumors are uncommon neoplasms and can lead to systemic disorder including glucagonoma syndrome, a very rare prototypical paraneoplastic phenomenon. The aim of this study was to assess the diagnosis and surgical strategy for the treatment of glucagonoma syndrome. METHODS: The clinical data of a case of pancreatic head tumor with typical glucagonoma syndrome of necrolytic migratory erythema (NME), diabetes mellitus (DM), anemia, and glossitis were retrospectively analyzed. RESULTS: Cutaneous eruption occurred mainly in the groin, extremities, thighs, buttocks, and perineum. A highly elevated level of serum glucagon was detected by radioimmunoassay. A tumor located in the head of the pancreas was well-defined by pre and intra-operative ultrasonography, contrast enhanced computed tomography, and magnetic resonance imaging. Tumor enucleation was performed, showing significantly improved symptoms. Near complete resolution of NME was shown one week after surgery. Surgical complications or recurrence was not found. CONCLUSIONS: The diagnosis of glucagonoma syndrome is established by marked clinical features such as NME as the hallmark clinical finding, hyperglucagonemia, and radiographically demonstrated neuroendocrine tumor. The topographic diagnosis of glucagonoma can be achieved by combined imaging methods. Enucleation of tumor is a valuable treatment for solitary pancreatic tumor without peripancreatic invasion, liver metastasis, and pancreatic duct compression.

Glucagonoma↗
PubMed2003

Distinct intragraft response pattern in relation to graft size in liver transplantation.

BACKGROUND: The molecular mechanism of small-for-size graft injury remains unclear. The aim of this study is to investigate the gene expression pattern of acute phase response in relation to graft size in a rat-liver transplantation model. METHODS: A rat orthotopic liver transplantation model using 30%, 50%, and whole grafts was used. The graft survival rates and liver morphology were compared among the three groups. Two transcription factors, nuclear factor (NF)-kappaB (p65) and early growth response (Egr-1), and their downstream genes were compared. RESULTS: According to the graft size, the rats were grouped as follows: group 1 (n=20), 32% (24-47%); group 2 (n=10), 56% (50-65%); and group 3 (n=10), 104% (89-120%). The 7-day survival rates were 20% (P=0.039 vs. group 2, P=0.000 vs. group 3), 60%, and 100% in groups 1, 2, and 3, respectively. Dilation of hepatic sinusoids and vacuolization of hepatocytes were observed in group 1. Up-regulation of Egr-1 and endothelin (ET)-1 and over-expression of nitric oxide synthase (iNOS) was found in group 1, but heme oxygenase (HO)-1 and A20 were down-regulated. At 24 hours after reperfusion, the intragraft protein level of heat-shock protein (Hsp)-70 was significantly lower in group 1 than that in group 3 (12.4 vs. 17.0 ng/mL, P=0.04). More apoptotic nuclei were found in group 1. CONCLUSIONS: Small-for-size graft injury was related to early over-expression of Egr-1 associated with up-regulation of ET-1 and deterioration of intracellular homeostasis reflected by down-regulation of Hsps and A20.

Acute-Phase Reaction↗
PubMed2003

Reductions in symptom distress reported by patients with moderately severe, nonerosive gastroesophageal reflux disease treated with rabeprazole.

Gastroesophageal reflux disease (GERD) is characterized by heartburn and related symptoms that are distressing to patients and interfere with everyday functioning and well-being. A measure of symptom distress, the GERD Symptom Assessment Scale (GSAS), was included in two randomized, placebo-controlled trials of rabeprazole among patients with nonerosive GERD. The age (mean +/- SD) of the 223 patients was 43.5 +/- 11.9 years, and most were female (67%) and Caucasian (78%). Significantly greater reductions in symptom distress were observed among patients receiving rabeprazole 20 mg daily for 4 weeks relative to those receiving placebo (-0.62 vs -0.36, P < 0.0001). The magnitude of this treatment difference was comparable to the differences observed between levels of overall symptom improvement on the patient global rating (0.2 and 0.3 points; P < 0.0001). In conclusion, reducing symptom distress is an important goal of therapeutic interventions for GERD. Rabeprazole significantly reduced the distress associated with a broad range of GERD symptoms, and the magnitude of this effect was meaningful to patients.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

Risk factors for femicide in abusive relationships: results from a multisite case control study.

OBJECTIVES: This 11-city study sought to identify risk factors for femicide in abusive relationships. METHODS: Proxies of 220 intimate partner femicide victims identified from police or medical examiner records were interviewed, along with 343 abused control women. RESULTS: Preincident risk factors associated in multivariate analyses with increased risk of intimate partner femicide included perpetrator's access to a gun and previous threat with a weapon, perpetrator's stepchild in the home, and estrangement, especially from a controlling partner. Never living together and prior domestic violence arrest were associated with lowered risks. Significant incident factors included the victim having left for another partner and the perpetrator's use of a gun. Other significant bivariate-level risks included stalking, forced sex, and abuse during pregnancy. CONCLUSIONS: There are identifiable risk factors for intimate partner femicides.

Adult↗
PubMed2003

[Early diagnosis of pancreatic cancer is essential to improving the effect of treatment].

OBJECTIVES: To explore the relation between tumor TNM of pancreatic cancer and treatment, and to summarize the experience in diagnosis and treatment of pancreatic cancer. METHODS: The data on 321 patients with pancreatic cancer treated at our hospital between January 1990 and December 2000 were reviewed retrospectively. Radical resection and survival for various TNM stages were analyzed. RESULTS: The rates of radical resection for stage I, stage II, stage III, stage IVA, and stage IVB were 100%, 100%, 82.6%, 12.3% and 2.1% respectively. The 1-, 3- and 5-year survivals of stage I, II were 73.3%, 40.0% and 30.0% respectively, and higher than those of other groups. CONCLUSIONS: The patients with pancreatic cancer diagnosed early can undergo radical resection. The elevation of early diagnosis rate is significant for the improvement of survival.

Adolescent↗
PubMed2003

[Effect of dandi tablet on blood lipids and sex hormones in women of postmenopausal stage].

OBJECTIVE: To explore the effect of Dandi Tablet (DDT), a TCM preparation for tonifying Shen and activating blood circulation, on blood lipids and sex hormones in women of postmenopausal stage. METHODS: Seventy-three women were randomly divided into two groups. The 46 subjects in the DDT group were treated with DDT (consisted of prepared Rehmannia Root 24 g, Dogwood Fruit 9 g, Poria 9 g, Water-plantain 9 g, Tuber Peony bark 9 g, Chinese Yam 12 g and Red Sage 15 g, etc.) twice a day, 4 tablets each time. The 27 subjects in the control group were treated with nylestriol (each tablet contains 2.5 mg of 17 alpha-ethynylestriol-3-cyclopentyl ether) 5 mg every month, for 3 successive months. Levels of blood lipids, including total cholesterol (TC), triglyceride (TG), high and low density lipoprotein cholesterol (HDL-C, LDL-C), apoprotein A and B (apoA, apoB) and sex hormones, including follicular stimulating hormone (FSH) and estradiol (E2) were determined before and after treatment. RESULTS: Compared with pre-treatment, after treatment, levels of TC/HDL-C and FSH significantly lowered, HDL-C and E2 increased in both groups (P < 0.05 or P < 0.01), levels of TG lowered and apoA increased significantly in the DDT group (P < 0.05). CONCLUSION: DDT has the effect of elevating levels of estrogen and improving blood lipid metabolism, therefore shows a coronary heart disease preventive effect in women of postmenopausal stage.

Adult↗
PubMed2003

The effect of mycophenolate acid on hepatitis B virus replication in vitro.

OBJECTIVE: To use 2.2.15 cell line to determine the effects of mycophenolate acid (MPA) on hepatitis B virus (HBV) replication and viral protein synthesis in vitro. METHODS: The 2.2.15 cells were treated with different concentration of MPA (1-50 mug/ml) for 12 days. HBsAg and HBeAg were detected in the supernatant fluid by ELISA and intracellular HBV DNA was analyzed quantitatively by slot blot hybridization. RESULTS: MPA could suppress the expression of HBsAg and HBeAg, and the higher concentration of MPA induced lower expression of HBsAg and HBeAg. The suppression rates of MPA for HBsAg and HBeAg at a concentration of 50 micrograms/ml were 34.2% and 24.1% respectively. The expression of HBV DNA was only 49% as compared with controls when treated with MPA at a concentration of 50 micrograms/ml. CONCLUSIONS: Mycophenolate acid can suppress the expression of HBsAg and HBeAg as well as the replication of HBV DNA in the 2.2.15 cell. The suppressive degree is dose-dependent.

Cell Line↗
PubMed2002

Dielectrophoretic cell separation and gene expression profiling on microelectronic chip arrays.

Cell membrane dielectric properties of five different cultivated cell lines and human peripheral blood mononuclear cells (PBMC) were determined from dielectrophoretic crossover frequency measurements on a 5 x 5 microelectronic chip array. Based on distinct dielectric property differences between individual cell types, efficient cell separations were achieved by dielectrophoresis on this 5 x 5 array, which included separation of monocytic cells (U937) or human T cell leukemia virus type 1 (HTLV-1) tax-transformed cells (Ind-2) from PBMC, as well as separation of neuroblastoma cells (SH-SY5Y) from glioma cells (HTB). The purity of dielectrophoretically separated cells can be greater than 95%. Expression profiles of IL-1, TNF-alpha, and TGF-beta genes for U937 cells mixed with PBMC before and after the separation were determined by a means of electric field-facilitated hybridization on a 10 x 10 microelectronic chip array. By using the expression levels of pure U937 cells as a control, it was shown that the gene expression profiles of the postseparation cells were significantly different from those of the preseparation cell mixtures. The increase in gene expression levels for U937 cells upon lipopolysaccharide induction could be accurately determined only in the postseparation cells, while the preseparation samples masked these changes. Furthermore, by cultivating the separated HTB and SH-SY5Y cells and measuring expression of the stress-related gene c-fos, dielectrophoretic forces were shown to have little effect on cell survival and stress. The presented approach of using microelectronic chip arrays for both cell separation and gene expression profiling provides a great potential for accurate genetic analysis of specific cell subpopulations in heterogeneous samples.

Cell Line↗
PubMed2002

Interdomain engineered disulfide bond permitting elucidation of mechanisms of inactivation of coagulation factor Va by activated protein C.

Procoagulant factor Va (FVa) is inactivated via limited proteolysis at three Arg residues in the A2 domain by the anticoagulant serine protease, activated protein C (APC). Cleavage by APC at Arg306 in FVa causes dissociation of the A2 domain from the heterotrimeric A1:A2:A3 structure and complete loss of procoagulant activity. To help distinguish inactivation mechanisms involving A2 domain dissociation from inactivation mechanisms involving unfavorable changes in factor Xa (FXa) affinity, we used our FVa homology model to engineer recombinant FVa mutants containing an interdomain disulfide bond (Cys609-Cys1691) between the A2 and A3 domains (A2-SS-A3 mutants) in addition to cleavage site mutations, Arg506Gln and Arg679Gln. SDS-PAGE analysis showed that the disulfide bond in A2-SS-A3 mutants prevented dissociation of the A2 domain. In the absence of A2 domain dissociation from the A1:A2:A3 trimer, APC cleavage at Arg306 alone caused a sevenfold decrease in affinity for FXa, whereas APC cleavages at Arg306, Arg506, and Arg679 caused a 70-fold decrease in affinity for FXa and a 10-fold decrease in the k(cat) of the prothrombinase complex for prothrombin without any effect on the apparent K(m) for prothrombin. Therefore, for FVa inactivation by APC, dissociation of the A2 domain may provide only a modest final step, whereas the critical events are the cleavages at Arg506 and Arg306, which effectively inactivate FVa before A2 dissociation can take place. Nonetheless, for FVa Leiden (Gln506-FVa) inactivation by APC, A2 domain dissociation may become mechanistically important, depending on the ambient FXa concentration.

Anticoagulants↗
PubMed2002

[Orthotopic liver transplantation for end-stage liver diseases in 71 cases].

OBJECTIVE: To assess the role of orthotopic liver transplantation (OLT) in the treatment of end-stage liver diseases and to discuss the experience of the operation. METHODS: Retrospective analysis of clinical data of 71 cases of liver transplantation was performed in our hospital from April 1993 to August 2001. RESULTS: One year survival rate of recipients with benign hepatic disease was over 75%. The survival time and life quality of malignant recipients were also improved. Lamivudine monotherapy during the operation period could reduce HBV reinfection rate. The practice of OLT without veno-venous bypass (VVB) was associated with a shorter operating time, less hemorrhape, and thus less blood transfusion during the operation compared with standard technique of OLT with routine use of VVB. The occurrence rate of biliary complications was 5.98% and vascular complication 8.96%. CONCLUSIONS: OLT should become a routine therapeutic choice for end-stage liver diseases. Lamivudine is helpful to reduce HBV reinfection after OLT in HBV-related liver diseases. OLT without VVB is safe and can be performed in the majority of adult patients. The early diagnosis and timely application of interventional radiological technique are important for the treatment of biliary and vascular complications.

Adolescent↗
PubMed2002

[Orthotopic liver transplantation with no veno-venous bypass].

OBJECTIVE: To assess the feasibility and outcome of orthotopic liver transplantation (OLT) with no veno-venous bypass (VVB) in adult patients. METHODS: Between 1999 and June 2001, 43 adult patients were subjected to orthotopic liver transplantations with veno-venous bypass (28), or no veno-venous bypass (15). RESULTS: There was no significant difference in mean serum creatinine on day 3 and gas discharge time in patients with veno-venous bypass or not. With no veno-venous bypass, the average operative time was 5.6 +/- 1.4 h, median amount of blood loss during operation was 4 200 +/- 850 ml, median amount of blood transfused intraoperatively was 4 800 +/- 920 ml, and median intensive care unit stay was 6.3 days. All these were lower or shorter than those of the patients with veno-venous bypass. CONCLUSIONS: Orthotopic liver transplantation with no veno-venous bypass is safe and can be performed in the majority of adult patients. Liver transplantation with no veno-venous bypass is associated with shorter total operating time, lower blood product usage, and shorter intensive care unit stay compared with standard technique of OLT with routine use of VVB.

Adult↗
PubMed2002

Multiplexed, targeted gene expression profiling and genetic analysis on electronic microarrays.

BACKGROUND: Electronic microarrays comprise independent microelectrode test sites that can be electronically biased positive or negative, or left neutral, to move and concentrate charged molecules such as DNA and RNA to one or more test sites. We developed a protocol for multiplexed gene expression profiling of mRNA targets that uses electronic field-facilitated hybridization on electronic microarrays. METHODS: A multiplexed, T7 RNA polymerase-mediated amplification method was used for expression profiling of target mRNAs from total cellular RNA; targets were detected by hybridization to sequence-specific capture oligonucleotides on electronic microarrays. Activation of individual test sites on the electronic microarray was used to target hybridization to designated subsets of sites and allow comparisons of target concentrations in different samples. We used multiplexed amplification and electronic field-facilitated hybridization to analyze expression of a model set of 10 target genes in the U937 cell line during lipopolysaccharide-mediated differentiation. Performance of multiple genetic analyses (single-nucleotide polymorphism detection, gene expression profiling, and splicing isoform detection) on a single electronic microarray was demonstrated using the ApoE and ApoER2 genes as a model system. RESULTS: Targets were detected after a 2-min hybridization reaction. With noncomplementary capture probes, no signal was detectable. Twofold changes in target concentration were detectable throughout the ( approximately 64-fold) range of concentrations tested. Levels of 10 targets were analyzed side by side across seven time points. By confining electronic activation to subsets of test sites, polymorphism detection, expression profiling, and splicing isoform analysis were performed on a single electronic microarray. CONCLUSIONS: Microelectronic array technology provides specific target detection and quantification with advantages over currently available methodologies for targeted gene expression profiling and combinatorial genomics testing.

Alternative Splicing↗
PubMed2002

[Effects of different class II cavity designs on stresses in restoration].

OBJECTIVE: To assess effects of different class II cavities on stresses of amalgam and composite resin restoration. METHODS: Five kinds of class II MO cavities were prepared on the first molars of mandibles. The cavities were filled by amalgam and composite resin, respectively. The stresses were analyzed by using three-dimensional finite element method, after vertical and lateral pressures were loaded on the teeth. RESULTS: The stresses were greater in traditional cavities than those in reformed cavities when 100 N vertical and lateral pressures were loaded on the teeth. But the pressing stress and shearing stress in cavities filled by amalgam were smaller in traditional cavities than those in reformed cavities. The stresses were smaller in cavities filled by resin than those in cavities filled by amalgam significantly, when the cavities were designed with slot retention groove, without slot retention groove and as plate form. The stresses were smaller in two kinds of slot and plate cavities than those in traditional and reformed cavities. CONCLUSION: It is better to design cavity with slot retention groove for amalgam restoration and to design cavity without slot retention groove for composite resin restoration.

Composite Resins↗
PubMed2002

Orthotopic liver transplantation in treatment of 77 patients with end-stage hepatic disease.

OBJECTIVE: To summarize the experience of human orthotopic liver transplantation (OLTx) in treatment of patients with end-stage hepatic disease and their perioperative management. METHODS: A retrospective analysis was made on OLTx performed in 77 patients from April 1993 to September 2001 in our department included combined liver-kidney transplantation (6 patients) and living related liver transplantation (2). Among them, 76 were adults and 1 was infant (67 males and 10 females). The donors included 75 non-heart beating donors and 2 living related donors. Veno-venous bypass was used only in 45 cases during the operation. immunosuppressive agents consisted of cyclosporine, cellcept, ALG corticosteroids and FK506. RESULTS: The one-year survival rates of grafts and recipients with benign hepatic disease were 75%. The recipients this year are surviving with good function of grafts. CONCLUSION: Liver transplantation is the best therapeutic method for a large number of patients with end-stage hepatic disease in China.

Adolescent↗
PubMed2002

Clinical experience in liver transplantation from an organ transplantation center in China.

OBJECTIVE: To sum up the experience in liver transplantation in a period of ten years at a single center. METHODS: We retrospectively reviewed the clinical records of 120 patients receiving liver transplantation from April 1993 to October 2002. The patients' clinical characteristics, surgical techniques, complications and survival were compared in the phases of 1993-1997 (phase I), 1999 (phase II), and 2000-2002 (phase III). RESULTS: Malignant liver diseases were major indications for liver transplantation in phase I (100%) and II (53.3%), but decreased markedly in percentage in phase III (34.0%). When compared with recipients in phase I and II, the survival of recipients with benign liver diseases in phase III was significantly improved with the 3-month, 6-month and 1-year survival rates of 85.7%, 84.5% and 83.1%, respectively. For patients with malignant liver diseases, the 3-month, 6-month and 1-year survival rates were 87.4%, 81.1% and 46.0%, respectively. The reinfection rate of hepatitis B virus was 24% 12 months after transplantation. With technical refinements, the incidence of postransplantation vascular complications has significantly decreased from 29.4% in phase I and II to 4.9% in phase III. Biliary complications remained one of the major obstacles to long-term survival. No veno-venous bypass was applied in phase III, providing a promising outcome. CONCLUSION: Strict selection of potential recipients, technical refinement, appropriate management of vascular and biliary complications, and prophylaxis of recurrences of hepatitis B and malignant liver diseases are important to obtain long-term survival of patients receiving liver transplantation in China.

Adult↗