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Xu Yang

Publications and source records attributed to Xu Yang.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Study of effects of HBV X gene and As2O3 on expression and activity of p53 in HepG2 cells with shRNA].

OBJECTIVE: To delineate the effects of HBV X gene and of As(2)O(3) on p53 expression and activity in HepG2 cells by shRNA-mediated RNA interference (RNAi). METHODS: HepG2 cells and cells with stable expression of HBV X gene, HepG2-X, were treated with 2 micromol/L As(2)O(3), and the corresponding untreated cells were used as controls. Cell and nuclear lysates were extracted. Total level and the relative activity absorbance of p53 were detected by modified ELISA. HBV X gene sequence-specific shRNA expression vectors, Xi-S1 and Xi-S2, and sequence-unrelated control Xi-S3 were transfected into HepG2-X. The effect of As(2)O(3) on p53 expression and activity were retested. RESULTS: Total p53 level was up-regulated and its relative activity ratio was enhanced by As(2)O(3) in HepG2 and HepG2-X cells. The total p53 level induced by As(2)O(3) was further up-regulated by HBX expression, while its relative activity was significantly suppressed. The suppression was removed after HBX expression was suppressed by shRNA. CONCLUSION: As(2)O(3) could up-regulate p53 expression and enhance its activity. shRNA-mediated RNA interference is conveniently being used in studies on the effect of HBV X gene expression on p53 expression and activity. HBV X expression could up-regulate p53 gene expression level induced by As(2)O(3), while it suppressed the activity of p53.

Apoptosis↗
PubMed2006

[Direct sequencing and analysis of exons of Wilson' disease gene with the most mutations: a study in Hunan Han patients].

OBJECTIVE: To detect hot point mutations of ATP7B gene in Hunan Han patients with Wilson' disease (WD). METHODS: The genomic DNA of 22 WD patients was extracted and exons 5, 8, 12, 13 were amplified by PCR. Screening for the mutations was done by direct sequencing and analysed by BLAST. RESULTS: Fifteen of the 22 patients were found with mutations. Ten heterozygous Arg778Leu (2273G --> T) mutations were found in exon 8, all of them were accompanied with 2250C --> G polymorphism (Leu770Leu). Seven patients were found with 2855G --> A (Arg952Lys) polymorphism (4 heterozygous and 3 homozygous), 3 of them had Arg778Leu mutation in exon 8 and one with heterozygous mutation Gly943Asp (2828G --> A) in exon 12 simultaneously. Only one patient was found with heterozygous Pro992Leu (2975C --> T) mutation in exon 13. No mutations were found in exon 5. CONCLUSION: Arg778Leu is the hot point mutation of ATP7B gene in Hunan Han patients with Wilson' disease while exon 5 is not.

Adenosine Triphosphatases↗
PubMed2005

Impedance labelless detection-based polypyrrole protein biosensor.

A simple and sensitive electrochemical immunosensor with impedance labelless detection and novel data processing method was investigated. One-step copolymerization was used to electrochemically deposit an antibody impregnated polypyrrole film on a glassy carbon electrode surface for the immunosensor. Impedance measurements provided a labelless or reporterless method to detect antibody (Ab)-antigen (Ag) interactions. Dimensionless analysis was employed to successfully process the measured impedance data. Since the method derived unit impedance change to eliminate or reduce the variation of the bulk electronic properties of Ab/polypyrrole films, the signal to noise ratio (S/N) was significantly improved for high sensitivity and specificity. Nonspecific binding effect was studied by array electrode chips and was found out that the polypyrrole electrode without antibody attachment had much stronger nonspecific binding effect than the Ab/polypyrrole electrode; incubation followed by thoroughly washing significantly reduced the nonspecific interference. 10 pg/ml detection limit and superior specificity were achieved by the method, demonstrating a highly sensitive labelless immunosensor in comparison with the detection limit of ng -microgram/ml for the reported polypyrrole based immunosensors. The electrochemical immunosensors presented in this paper, due to its simplicity, low cost, high sensitivity and superior specificity, could be an invaluable tool for clinical diagnostics and could have potential applications in drug discovery, environmental and food analysis.

Antibodies↗
PubMed2005

Type II vanilloid receptor signaling system: one of the possible mechanisms for the rise in asthma cases.

The prevalence of asthma keeps on increasing worldwide, especially in western societies over last 40 years. The mechanism of asthma is unclear. Recently, concern about indoor air pollution as a risk factor for asthma has been arisen. In present study, 25 Kun Ming male mice were placed in an air chamber containing respective formaldehyde (FA) concentration of 0, 0.5, 1.0, 3.0 mg/m3,and 3.0 mg/m3 with Capsazepine (CPZ, a specific antagonist of vanilloid receptor)-pretreatment in five testing groups (n=5 per group) for inhale experiments. The inhaled groups were exposed to gaseous FA for 6 hours each day in 10 successive days. After exposure, the concentrations of IL4 in blood serum and broncho alveolar lavage fluid (BALF) were measured. Experimental results showed that the IL4 level in serum was too low to be detected; and the concentrations of IL4 in BALF increased in a dose-dependent manner. However, for the CPZ-pretreated group the IL4 level in BALF decreased significantly (compared with 3.0 mg/m3 FA inhaled group, p<0.01). This paper describes experimental animal methods to probe IL4 level, an important indicator for IgE response. The studies in this paper indicated that gaseous FA might induce acquired atopy by type II VR1 signaling system. These findings suggested that indoor air pollutants such as FA might be key risk factors for the rise in asthma cases, and type II VR1 signaling system might be one of the mechanisms for the rise.

Animals↗
PubMed2005

Plasma homocysteine thiolactone adducts associated with risk of coronary heart disease.

BACKGROUND: Homocysteine thiolactone adducts have been proposed as the culprit of homocysteine related cardiovascular diseases. We studied the association of these adducts in plasma, and the gene polymorphism of paraoxonase-2 with coronary heart disease. METHODS: 254 patients and 308 controls were recruited for the study. Homocysteine thiolactone adducts were determined with ELISA. The codon 311 polymorphism of paraoxonase-2 gene was genotyped by using polymerase chain reaction and restrictive digestion. RESULTS: The plasma level of homocysteine thiolactone adducts were significantly higher in patients than in controls (40.65 +/- 10.87 u/ml vs. 30.58 +/- 10.20 u/ml, P <0.01), with odds ratio of 7.34 (95% confidence interval 4.020-13.406, P <0.01), and increased according to the number of atherosclerotic coronary arteries: 35.59 +/- 10.34 units/ml (n = 76); 41.88 +/- 8.83 (n = 70) and 43.13 +/- 11.47 (n = 108) in subjects with 1, 2 and 3 affected arteries, respectively (r =0.174, P < 0.01). The frequency of CC genotype was significantly higher in patients with coronary heart disease (7.48%) than in controls (1.62%, P < 0.01), with adjusted odds ratio of 4.367 (95% confidence interval: 1.178 to 16.191, P < 0.01), so was the C allele (23.2% vs. 14.9%, P < 0.05). CONCLUSIONS: High plasma homocysteine thiolactone adducts and the CC 311 genotype of paraoxonase-2 gene may be the emerging risk factor for coronary heart disease.

Adult↗
PubMed2005

Vitamin k epoxide reductase: a protein involved in angiogenesis.

Vitamin K epoxide reductase (VKOR) is a newly identified protein which has been reported to convert the epoxide of vitamin K back to vitamin K, a cofactor essential for the posttranslational gamma-carboxylation of several blood coagulation factors. We found that the gene is expressed ubiquitously including vascular endothelial cells, smooth muscle cells, fibroblasts and cardiomyocytes, and is overexpressed in 11 tumor tissues on microarray. Stable transfection of VKOR cDNA into tumor cell line A549 and H7402 did not promote the cell proliferation. These results promoted us to hypothesize that VKOR may also be involved in angiogenesis. To test this hypothesis, the expression of VKOR was studied in different vascular cells in developmental and pathologic heart tissues. The effects of overexpression and suppressing expression of VKOR on endothelial cell proliferation, migration, adhesion, and tubular network formation were explored. We found that VKOR expression in arteries was prominent in vascular endothelial cells and was high in the ventricular aneurysm tissue of human heart and human fetal heart. In vitro studies showed that overexpression of VKOR slightly but significantly stimulated human umbilical vein endothelial cell proliferation (by 120%), migration (by 118%), adhesion (by 117%), as well as tubular network formation. Antisense to VKOR gene inhibited the proliferation (by 67%), migration (by 64%), adhesion (by 50%), and tubular network formation. Our findings support the impact of VKOR in the process of angiogenesis; hence, the molecule may have a potential application in cardiovascular disease and cancer therapy.

Adenoviridae↗
PubMed2005

A chemometric analysis for evaluation of early-stage cartilage degradation by infrared fiber-optic probe spectroscopy.

In vivo identification of early-stage cartilage degradation could positively impact disease progression in osteoarthritis, but to date remains a challenge. The primary goal of this study was to develop an infrared fiber-optic probe (IFOP) chemometric method using partial least squares (PLS1) to objectively determine the degree of cartilage degradation. Arthritic human tibial plateaus (N = 61) were obtained during knee replacement surgery and analyzed by IFOP. IFOP data were collected from multiple regions of each specimen and the cartilage graded according to the Collins Visual Grading Scale of 0, 1, 2, or 3. These grades correspond to cartilage morphology that displayed normal, swelling or softening, superficially slight fibrillation, and deeper fibrillation or serious fibrillation, respectively. The model focused on detecting early cartilage degradation and therefore utilized data from grades 0, 1, and 2. The best PLS1 calibration utilized the spectral range 1733-984 cm(-1), and independent validation of the model utilizing 206 spectra to create a model and 105 independent test spectra resulted in a correlation between the predicted and actual Collins grade of R2 = 0.8228 with a standard error of prediction of 0.258 with a PLS1 rank of 15 PLS factors. A preliminary PLS1 calibration that utilized a cross-validation technique to investigate the possibility of correlation with histological tissue grade (33 spectra from 18 tissues) resulted in R2 = 0.8408 using only eight PLS factors, a very encouraging outcome. Thus, the groundwork for use of IFOP-based chemometric determination of early cartilage degradation has been established.

Aged↗
PubMed2005

[Ceruloplasmin level of patients with liver disease in China].

OBJECTIVE: To find out the degree of overlap of ceruloplasmin concentration in patients presenting with liver disease, providing scientific evidences for the diagnosis and differential diagnosis of Wilson's disease (WD). METHODS: Measuring the serum ceruloplasmin concentration of patients presenting with liver diseases, all data were statistically analyzed with SPSS12 for Windows. RESULTS: The average serum ceruloplasmin concentration of patients with WD was (93.9 +/- 98.1) mg/L, which was significantly lower than patients with non WD. The ceruloplasmin concentration of 72.7% of patients with WD was less than 100 mg/L, and that of 42.9% of patients with WD was less than 50 mg/L, but the ceruloplasmin concentration of 9.1% of patients with WD was more than 210 mg/L. The average serum ceruloplasmin concentration of patients with acute hepatitis was (398.4 +/- 151.3) mg/L, which was significantly higher than other group. The average serum ceruloplasmin concentration of patients with severe hepatitis was (296.5 +/- 106.5) mg/L, which was significantly lower than other group. The ceruloplasmin concentration of 6.8% of patients with non WD was less than 210 mg/L, the lowest was 28 mg/L. CONCLUSIONS: There is some degree overlap in ceruloplasmin concentration between WD and other liver disease, WD could not be confirmed or excluded according to ceruloplasmin concentration only.

Ceruloplasmin↗
PubMed2005

[Clinical and experimental study of the therapeutic effect of umbilical cord blood stem cell transplantation on liver failure and heart damage in severe viral hepatitis patients].

OBJECTIVE: To investigate and compare the therapeutic effect of umbilical cord blood stem cell transplantation (UCBSCT) or adult fresh plasma in severe viral hepatitis liver failure with/without heart damage, and to study the effect of UCBSCT on liver lesions in rats. METHODS: 83 severe hepatitis patients with/without heart damage were included in the study between January 1994 and June 2003. The patients were treated with UCBSCT or given adult plasma transfusions. The therapeutic effect was evaluated by serial determination of liver function and myocardium enzymes in all patients before and after the treatment. The model of experimental hepatic failure was constructed in SD rats by injecting carbon tetrachloride. Then, the rats were given normal saline, neonate cord blood serum or neonate cord blood stem cells respectively. The expression of human AFP and Alb in SD rat livers was detected by immunohistochemistry; and human special DNA was detected by PCR. RESULTS: The UCBSCT group had much better effects in the improvement of liver function than the adult plasma group had, no matter whether the patients had heart damage or not. Moreover, UCBSCT can decrease heart impairment of the patients. The animal experiment demonstrated that AFP and Alb positive cells were present in the neonate cord blood stem cell group after 21 days and 1 month; human special DNA was detected by PCR in these SD rat livers. CONCLUSION: UCBSCT displayed good therapeutic effects on severe viral hepatitis and improvement of heart injury of the patients. The rat liver immunohistochemistry indicated that neonate cord blood stem cell application can decrease the liver damage and increase hepatocellular regeneration. Human umbilical cord blood stem cells can differentiate into liver cells in acute damaged SD rat livers.

Aged↗
PubMed2005

[Interferon-alpha and ribavirin combination therapy for co-infection of hepatitis C virus and human immunodeficiency virus].

OBJECTIVE: To evaluate the clinical effect and side-effect of interferon-alpha (IFN-a) and ribavirin (RBV) combination therapy for Chinese patients with co-infection of hepatitis C virus (HCV) and human immunodeficiency virus (HIV), and to compare them with only HIV infection patients. METHODS: 10 patients with HCV-HIV and 17 patients with only HCV infection received 5 million units of IFNalpha-2b every other day intramuscularly, and 300 mg RBV orally three times a day. Dynamic observations were done for HCV RNA and HIV RNA loads, CD4+ and CD8+ T lymphocyte counts, liver function and blood cell measures, and the side-effects of the medicines. RESULTS: After 12 weeks and 24 weeks of IFNalpha and RBV combination therapy, mean HCV RNA levels reduced 1.14 log (t = 3.843, P < 0.01) and 2.08 log (t =6.564, P < 0.01) from the baseline at week 0 in the HCV-HIV co-infection group, and reduced 1.48 log (t = 6.438, P less than 0.01) and 2.33 log (t = 7.343, P < 0.01) in the HCV infection group. Meanwhile, the HIV RNA levels decreased 1.22 log (t = 3.662, P < 0.01) and 1.73 log (t = 6.119, P < 0.01) from the base line. However, there were no obvious different changes among T lymphocyte counts of HCV-HIV and HCV patients at week 0, week 12 and week 24. All 27 patients showed satisfactory biochemical response to therapy. There were some mild or moderate influenza-like symptoms, intestinal discomfort and decreased blood cell counts in the early stages of the treatments. No neuropsychic and auto-immune disorders were found. CONCLUSIONS: IFNalpha-2b and RBV combination therapy showed similar anti-HCV effects during the 24 week treatment for HCV-HIV and HCV infected patients, and some anti-HIV effect was also observed. No obvious different biochemical responses and side-effects were found between the above two groups.

Adult↗
PubMed2005

[Population structure and community characteristics of Pseudotaxus chienii in Fengyangshan National Natural Reserve].

Pseudotaxus chienii, an endemic plant in China, is one of the second grade state protection wild plants, and distributes in Fengyangshan Natural Reserve as one of its concentrative dwelling places. A survey in the region was carried out on 10 communities, which were dominated by P. chienii. The analysis on its size structure, spatial distribution pattern and community characteristics showed that the populations of P. chienii could grow in the communities dominated by Rhododendron simiarum, Fokienia hodginsii-R. simiarum, and evergreen broad-leaved forests. In R. simiarum communities, the size structure, survival curve, and overwhelming community distribution pattern of P. chienii showed a sustaining development, while in communities dominated by F. hodginsii-R. simiarum, though the size structure was declining, the survival curve was Deevy- III type. Plenty of plantlets were still existed, and the populations kept steady. Two types were considered to be the most suitable ones for P. chienii populations. The important value of P. chienii reached 5% - 10%. In evergreen broad-leaved forests, the populations of P. chienii showed to be a declining type, and the survival curve was Deevy- II type. The distribution pattern was random, indicating that P. chienii populations could not fit for survive in this kind of communities. Correlation analysis showed that P. chienii populations had a positive correlation with R. simiarum and F. hodginsii, but a negative correlation with Cyclobalanopsis stewardiana and Schima superba. P. chienii could associate to the habits with the community canopy density of about 0.6 - 0.8. From the results mentioned above, the populations of P. chienii could be able to sustain and develop, and the existing habitat in Fengyangshan should be protected effectively. The protection of P. chienii requires more basic work to establish efficient measures to protect its habitat.

China↗
PubMed2005

[Construction of two hepatocellular carcinoma cell models for the expression of HBV X gene with different selection characteristics].

OBJECTIVE: To construct 2 hepatocellular carcinoma (HCC) cell models for the expression of HBV X gene with different selection characteristics. METHODS: HepG2 HCC cells were infected with eukaryotic expression vectors with HBV X gene, pCEP4-X, and pcDNA3. 1 (+)-X. Single cell clone was selected by hygromycin and neomycin. After propagating culture for certain periods, the HBV X gene expression was identified by PCR, RT-PCR, and Western blot. RESULTS: Single HCC cell clone with HBV X gene transferred resistant to hygromycin and neomycin was selectively cultured, and the cells could be propagated for certain periods. PCR, RT-PCR, and Western blot identified the expression of HBV X gene. CONCLUSION: Two HCC cell models for the expression of HBV X gene with different selection characteristics have been successfully constructed.

Carcinoma, Hepatocellular↗
PubMed2004

A genetic variation map for chicken with 2.8 million single-nucleotide polymorphisms.

We describe a genetic variation map for the chicken genome containing 2.8 million single-nucleotide polymorphisms (SNPs). This map is based on a comparison of the sequences of three domestic chicken breeds (a broiler, a layer and a Chinese silkie) with that of their wild ancestor, red jungle fowl. Subsequent experiments indicate that at least 90% of the variant sites are true SNPs, and at least 70% are common SNPs that segregate in many domestic breeds. Mean nucleotide diversity is about five SNPs per kilobase for almost every possible comparison between red jungle fowl and domestic lines, between two different domestic lines, and within domestic lines--in contrast to the notion that domestic animals are highly inbred relative to their wild ancestors. In fact, most of the SNPs originated before domestication, and there is little evidence of selective sweeps for adaptive alleles on length scales greater than 100 kilobases.

Alleles↗
PubMed2004

Transfusion-related acute lung injury resulting from designated blood transfusion between mother and child: a report of two cases.

Transfusion-related acute lung injury (TRALI) is an underdiagnosed serious complication of blood transfusion characterized by the rapid onset of respiratory distress, hypoxia, and noncardiogenic pulmonary edema during or soon after blood transfusion. The presence of anti-HLA and/or antigranulocyte antibodies in the plasma of donors is implicated in the pathogenesis of TRALI. We report 2 cases of TRALI that were caused by designated blood transfusion between mothers and their daughters; one in a 4-month-old girl who received designated packed RBCs donated by her mother and the second in a 78-year-old mother who received blood from her daughter. In both cases, examination of mother's serum revealed panel-reactive cytotoxic HLA antibodies. It is most likely that the mothers were sensitized from earlier pregnancy and produced HLA antibodies against the daughters' paternally derived HLA antigens. Designated blood transfusion between multiparous mothers and children might add an additional transfusion-related risk owing to the higher likelihood of the HLA antibody-antigen specificity between mother and child.

Adult↗
PubMed2004

Insulin-like growth factor-I signaling is modified during chondrocyte differentiation.

Insulin-like growth factor-I (IGF-I) is a critical regulator of skeletal growth. While IGF-I has been shown to be a potent chondrocyte mitogen in vitro, its role in chondrocyte differentiation is less well characterized. We chose to study the action of IGF-I on an accepted model of chondrocyte differentiation, the ATDC5 cell line. Insulin concentrations sufficiently high to interact with the IGF-I receptor are routinely used to induce ATDC5 cells to differentiate. Therefore, we first examined the ability of IGF-I to promote chondrocyte differentiation at physiological concentrations. IGF-I could induce differentiation of these cells at concentrations below 10 nM. However, increasing IGF-I concentrations were less potent at inducing differentiation. We hypothesized that mitogenic effects of IGF-I might inhibit its differentiating effects. Indeed, the extracellular-signal-regulated kinase (ERK)-pathway inhibitor PD98059 inhibited ATDC5 cell DNA synthesis while enhancing differentiation. This suggested that the ability of IGF-I to promote both proliferation and differentiation might require that its signaling be modulated through the differentiation process. We therefore compared IGF-I-mediated ERK activation in proliferating and hypertrophic chondrocytes. IGF-I potently induced ERK activation in proliferating cells, but minimal ERK response was seen in hypertrophic cells. In contrast, IGF-I-mediated Akt activation was unchanged by differentiation, indicating intact upstream IGF-I receptor signaling. Similar findings were observed in the RCJ3.1C5.18 chondrogenic cell line and in primary chick chondrocytes. We conclude that IGF-I promotes both proliferation and differentiation of chondrocytes and that the differentiation effects of IGF-I may require uncoupling of signaling to the ERK pathway.

Animals↗
PubMed2004

Challenge in diagnosis of CD56+ lymphoproliferative disorders: two cases of CD56+CD33+ lymphoma/leukemia.

Two cases of CD56+CD33+ leukemia/lymphoma are reported. The patient in case 1 presented with skin rash, diffuse lymphadenopathy, and hepatosplenomegaly. Blasts with monocytoid and lymphoid features were present in the peripheral blood. The tumor cells expressed HLA-DR, CD4, CD33, CD38, and CD56. Cytogenetic analysis revealed del(2)(p13),del(9)(q22),add(6)(q25),add(12)(p12),-13,-18, and -20. The clinicopathologic features were similar to those of blastic natural killer cell leukemia/lymphoma or type 2 dentritic cell leukemia. The patient in case 2 presented with generalized weakness and skin erythema not responding to antibiotics. Circulating blasts with monocytoid features were seen in the peripheral blood. The tumor cells expressed CD7, CD13, CD33, CD38, and CD56, and cytogenetic analysis revealed -5,add(7)(p22),-8, del(10)(p11.2),-12,der(13; 14)(p10;p10),+14,-16,-18,-19, and del(20)(q13.1). The clinicopathologic features were consistent with a myeloid/ natural killer cell precursor acute leukemia. Both disorders are aggressive hematopoietic malignancies that have similar clinical presentation and morphology but differ in immunophenotype and cytogenetic features.

Aged↗