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Biomedical subjects

H Wang

Publications and source records attributed to H Wang.

At least 505 records · Page 28Linked to original sources
PubMed2001

New amino acid substitutions in the IRS-2 gene in Finnish and Chinese subjects with late-onset type 2 diabetes.

We investigated the significance of the variants of the IRS-2 gene in patients with type 2 diabetes. The entire coding part of the IRS-2 gene was screened by single-strand conformation polymorphism analysis in 40 Chinese and 40 Finnish patients with late-onset type 2 diabetes. The association of the variants of the IRS-2 gene with type 2 diabetes was studied in 85 Finnish diabetic patients and 82 Finnish control subjects and in 100 Chinese diabetic patients and 85 Chinese control subjects. The four variants predicting structural changes in the insulin receptor substrate (IRS)-2 protein included an insertion of AAC (Asn) in the Asn repeat sequence centered around codons 29-36 (allele frequencies of 0 vs. 0.6% and 1.5 vs. 0%), the Ala157Thr substitution (0 vs. 0% and 0.5 vs. 0%), the Leu647Val substitution (0.6 vs. 0% and 0 vs. 0%), and the Gly1057Asp polymorphism (31 vs. 31% and 35 vs. 30%) (P = NS for all comparisons). Furthermore, six silent variants were observed (CGC147CGG, CCC155CCG, GCC156GCT, AGT723AGC, TGT816TGC, and CCC829CCT). The Gly1057Asp polymorphism was not associated with insulin resistance or impaired insulin secretion in Finnish subjects with normal glucose tolerance (n = 295) or impaired glucose tolerance (n = 38). These data indicate that structural variants of the IRS-2 gene were uncommon in Finnish and Chinese patients with type 2 diabetes. Thus, the variants in the coding part of the IRS-2 gene are unlikely to have a major role in the development of type 2 diabetes in Finnish or Chinese subjects.

Age of Onset↗
PubMed2001

Functional analysis of a minimal mouse serum amyloid A3 promoter in transgenic mice.

We report the generation of transgenic mice harboring the SAA3/LacZ transgene and analysis of its expression patterns in vivo following LPS-induced inflammation. Our results show that a 210-bp fragment of the mouse SAA3 promoter when placed in front of the LacZ gene was sufficient to confer basal and inflammation-induced reporter gene expression. Consistent with endogenous SAA3 expression, the basal level of LacZ expression was high in the lung and liver of newborn and 1-week-old transgenic mice. Its expression however decreased with increasing age and at 3-weeks ofage, LacZ expression was very low in the lung and was essentially undetectable in the liver. When SAA3/LacZ transgenic mice were injected with lipopolisaccharide to induce inflammation, beta-gal activities were increased approximately 6- and 16-fold in the lung and liver, respectively. Histological examination of lung and liver tissues stained with X-gal revealed that the LacZ transgene was expressed primarily in the macrophages. Thus, this minimal SAA3 promoter fragment contains the necessary regulatory sequences for its expression and cytokine responsiveness in macrophages albeit is insufficient to confer expression in hepatocytes.

Animals↗
PubMed2001

Induction and concurrent paclitaxel/carboplatin every 3 weeks with thoracic radiotherapy in locally advanced non-small-cell lung cancer: an interim report.

The paclitaxel/carboplatin combination has demonstrated promising activity in metastatic non-small-cell lung cancer (NSCLC); therefore, we mounted an exploratory study of these agents with thoracic radiation (TRT) in locally advanced NSCLC. Eligibility stipulated a Karnofsky performance status >or= 70%, weight loss or= 2 esophagitis has corresponded to length (> 16 cm) of esophagus in the radiation treatment field (Fisher's exact test, P = 0.006). The partial response rate to induction therapy was 40% and to the combined modality therapy was 60%. The median survival for all 49 patients is 15.3 months, with a median disease-free survival (DFS) of 7.8 months. In the subset of 22 patients treated on the phase I portion of the study, the median survival and DFS were 18.5 months and 13.5 months, respectively. Induction therapy with paclitaxel and carboplatin followed by concurrent chemoradiotherapy with the same agents is an active and well-tolerated treatment approach in locally advanced NSCLC. To date, paclitaxel 175 mg/m2 plus carboplatin AUC 5 administered at 3-week intervals for 2 cycles is safe in combination with TRT.

Journal Article↗
PubMed2001

Expression of metalloproteinases and its inhibitor in later stage of rabbit neointima development.

Neointima formation after arterial de-endothelialization refers not only to smooth muscle cell (SMC) migration and proliferation, but also involves extracellular matrix (ECM) metabolism. Most studies regarding the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in neointima have focused on the early phase of vascular remodeling. In this study, we examined the expression of MMP and TIMP in rabbit aortic neointima at a relatively late stage of lesion development, between 4 and 12 weeks after initial de-endothelialization. Northern blot analysis revealed expression of steady-state MMP-9 mRNA was increased up to the 4th week and MMP-2 mRNA to the 12th week after de-endothelialization. In situ hybridization shown that MMP positive cells were predominantly distributed in arterial neointima. Expression of TIMP-1 mRNA was continuously up-regulated up to the 12th week and TIMP-1 positive cells, primarily SMCs, were also localized to the neointimal tissue. Alteration at mRNA level was accompanied by that at protein level, as assessed by SDS-PAGE zymography for MMPs and immunoblotting for TIMP-1. The profile of alteration at protein level correlated well with that at mRNA level. These data suggest that synthesis of MMPs and TIMP is a prolonged process and arterial SMC is a major source of MMP production in arterial neointima. Enhanced synthesis of MMPs and TIMPs at late stage of neointimal development may contribute to arterial ECM metabolism.

Animals↗
PubMed2001

Efficacy of cetylpyridinium chloride in immersion treatment for reducing populations of pathogenic bacteria on fresh-cut vegetables.

The efficacy of cetylpyridinium chloride (CPC) immersion to reduce the numbers of three pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7) on three different fresh-cut vegetables (broccoli, cauliflower, and radishes) was studied. The fresh-cut vegetables were inoculated with one of the three pathogenic bacteria at a concentration of 10(5) CFU/ml for 1 h at room temperature and then treated with 0.1 or 0.5% CPC immersion for 1 min. Both Salmonella Typhimurium and E. coli O157:H7 plates were incubated from 48 to 72 h at 37 degrees C, and L. monocytogenes plates were incubated from 72 to 96 h before being counted. The results of three experiments showed that for the average of the three vegetables treated with 0.1 and 0.5% CPC, L. monocytogenes was reduced by 2.85 and 3.70 log CFU/g, Salmonella Typhimurium by 2.37 and 3.15 log CFU/g, and E. coli O157:H7 by 1.01 and 1.56 log CFU/g, respectively, in comparison with the vegetables treated with water only. The 0.5% CPC treatment was significantly different (P < 0.05) from the 0.1% CPC treatment on reduction of L. monocytogenes, Salmonella Typhimurium, and E. coli O157:H7. The CPC residual on the treated vegetables and their washing solutions were evaluated by using high-performance liquid chromatography.

Cetylpyridinium↗
PubMed2001

Structure, function, and regulation of human cystine/glutamate transporter in retinal pigment epithelial cells.

PURPOSE: The purpose of this investigation was to provide evidence for the expression of the cystine/glutamate transporter (x(c)(-)) in the human retinal pigment epithelial cell line ARPE-19, clone the light chain of the transporter from an ARPE-19 cell cDNA library and study its function, and investigate the regulation of this transporter by nitric oxide (NO) in ARPE-19 cells. METHODS: Uptake of radiolabeled cystine and glutamate was measured in ARPE-19 cells. The functional identity of x(c)(-) in these cells was established by substrate specificity and Na(+)-independence of the uptake process. The human x(c)(-) light chain (human xCT) was cloned from an ARPE-19 cell cDNA library. The functional identity of the cloned human xCT was investigated by heterologous coexpression of the light chain with the heavy chain (human 4F2hc) in HeLa cells. ARPE-19 cells were treated with or without the NO donor 3-nitroso-N:-acetylpenicillamine (SNAP) and the expression of x(c)(-) was studied at the functional and molecular levels. RESULTS: ARPE-19 cells take up cystine as well as glutamate in the absence of Na(+). Substrate specificity studies indicate that although the uptake of cystine in the absence of Na(+) is mediated by multiple amino acid transport systems including x(c)(-), the uptake of glutamate in the absence of Na(+) occurs exclusively via x(c)(-). The human xCT cloned from ARPE-19 cells is a protein of 501 amino acids. These cells express the heavy chain 4F2hc as evidenced from RT-PCR analysis. Coexpression of human xCT with 4F2hc in HeLa cells leads to the induction of cystine and glutamate uptake with characteristics similar to that of x(c)(-). The activity of x(c)(-) in ARPE-19 cells is upregulated by SNAP, and the process is associated with an increase in the expression of xCT with no detectable change in the expression of 4F2hc. CONCLUSIONS: ARPE-19 cells express the cystine/glutamate transporter x(c)(-) (the light chain xCT and the heavy chain 4F2hc) as is evident from functional and molecular studies. NO upregulates this transport system and the process is associated with an increase in xCT mRNA but with no change in 4F2hc mRNA.

Amino Acid Sequence↗
PubMed2001

Heparan sulfate and chondroitin sulfate proteoglycans inhibit E-selectin binding to endothelial cells.

E-selectin is a cell adhesion molecule involved in the initial rolling and adhesion of leukocytes to the endothelium during inflammation. In addition, in vitro studies have suggested that an interaction between E-selectin and binding sites such as sialyl Lewis X-containing oligosaccharides on endothelial cells may be important for angiogenesis. In order to investigate the binding of E-selectin to endothelial cells, we developed an ELISA assay using chimeric E-selectin-Ig molecules and endothelial cells fixed on poly-L-lysine coated plates. Our results indicate that E-selectin-Ig binds to both bovine capillary endothelial cells and human dermal microvascular endothelial cells in a calcium-dependent and saturable manner. The binding is inhibited markedly by heparin and by syndecan-1 ectodomain, and moderately by chondroitin sulfate, but not by sialyl Lewis X-containing oligosaccharides. These results suggest that heparan sulfate and chondroitin sulfate proteoglycans on endothelial cells are potential ligands for E-selectin.

Animals↗
PubMed2001

Diffusion anisotropy of the internal capsule and the corona radiata in association with stroke and tumors as measured by diffusion-weighted MR imaging.

BACKGROUND AND PURPOSE: Diffusion-weighted MR images have enabled measurement of directionality of diffusion (anisotropy) in white matter. To investigate differences in the anisotropy for various types of pathologic findings and the association between the anisotropy of tracts and neurologic dysfunction, we compared the anisotropy of the posterior limb of the internal capsule and the corona radiata between patients with stroke and those with tumors and between patients with and without hemiparesis. METHODS: Thirty-three patients consisting of 11 with tumors and 22 with ischemic disease (16 acute infarction, four old infarction, and two transient ischemic attack) and nine control patients were studied with a 1.5-T MR imager. Diffusion-weighted images were obtained with diffusion gradients applied in three orthogonal directions. The diffusion anisotropy measurements were obtained from regions of interests defined within the internal capsule and the corona radiata. RESULTS: The diffusion anisotropy was significantly reduced in all internal capsules and coronae radiata involved by infarcts, tumors, and peritumoral edema compared with that of the control patients (P <.0001). This reduction was most prominent in the tracts involved by tumors (P <.05). The anisotropy of the internal capsules and coronae radiata was significantly decreased in cases with moderate-to-severe hemiparesis as compared with those with no or mild hemiparesis (P <.0001). Diffusion anisotropy tended to be also reduced in normal-appearing internal capsules and coronae radiata that were remote from the involved segment of the corticospinal tract. CONCLUSION: The degree of impaired diffusion anisotropy may vary in different pathologic conditions and correlate with neurologic dysfunction. The measurement of diffusion anisotropy may provide additional information relating to neurologic function and transneuronal effects.

Adolescent↗
PubMed2001

Hepatitis B virus transgenic mice for the model of anti-hepatitis B virus drug study.

OBJECTIVE: To establish hepatitis B virus (HBV) transgenic mice models and to investigate if the model can be used for the evaluation of anti-HBV drugs. METHODS: HBV transgenic mice models were produced by microinjection to analyze the integration, expression of HBV in the transgenic mice by nested PCR, southern blot, immunohistochemistry, and ELISA. Sixty mice whose HBV DNA, HBsAg were positive were divided into 6 groups randomly, in which 3 groups were given drugs: lamivudine administrated by perfusion of stomach tube (100mg x kg(-1) x day(-1) for 21 days); thymosine administrated by abdomen injection (3mg x day(-1) for 90 days); and DNA vaccine of 100 microg by muscle injection. The other 3 groups were negative control. RESULTS: Lamivudine, thymosine and DNA vaccine made HBV DNA become negative in the serum of HBV transgenic mice. The negative ratio was highest in lamivudine treatment group. HBV DNA became positive again when lamivudine terminated. CONCLUSION: Limvudine, thymosine, and DNA vaccine can inhibit HBV replication. Transgenic mice might be used as the model for anti-HBV drug screening and evaluation.

Animals↗
PubMed2001

Investigation on the rheological properties of hepatocellular carcinoma cells and their relevance to cytoskeleton structure.

OBJECTIVE: To investigate the relevance of the rheological properties, i.e., viscoelasticities and adhesion to basement membrane components coated surface, of both hepatocytes and hepatocellular carcinoma (HCC) cells to the cytoskeleton structure. METHODS: Micropipette aspiration technique was adopted to measure viscoelastic coefficients and adhesion forces to 2 microg/ml collagen IV/1.25 microg/ml laminin coated surface of the cells. Two kinds of cytoskeleton perturbing agents, colchicine and cytochalasin D, were used to treat both HCC cells and hepatocytes and the effects of these treatments on cell viscoelastic coefficients and cell adhesion forces were investigated. RESULTS: Upon treatment of cells with colchicine in a concentration range of 1 to 60 mg/L, the elastic coefficients, especially the first elastic coefficient K1, and adhesion forces of hepatocytes generally tended to increase or increased significantly while, in contrast, viscoelastic coefficients and adhesion forces of HCC cells decreased obviously. Upon treatment of cells with cytochalasin D in a concentration range of 0.25-5.00 mg/L, viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with a larger magnitude for the decrease in elastic coefficients and adhesion forces of HCC cells than for those of hepatocytes. Adhesion forces of hepatocytes and HCC cells onto collagen IV/laminin coated surface varied similarly as viscoelastic coefficients under the action of the cytoskeleton perturbing agents. A significant positive correlation existed between changes of HCC cell adhesion forces on collagen IV/laminin coated surfaces and those of cell elastic coefficients (P<0.01). CONCLUSIONS: The effects of cochicine and cytochalasin D on rheological properties of HCC cells differed significantly either in ways or extents from those on rheological properties of hepatocytes. These results might reflect the difference in the state of cytoskeleton structure and function among these two kinds of cells.

Carcinoma, Hepatocellular↗
PubMed2001

Relative risk of high grade squamous intraepithelial lesion associated with prior abnormal Pap smears.

OBJECTIVE: Pap smear frequency remains controversial, especially for women with consecutive negative smears. We undertook the current study to ascertain the association of high grade squamous intraepithelial lesions (HSIL) and prior abnormal Paps. STUDY DESIGN: Women with biopsy-proven HSIL (cervical intraepithelial neoplasia 2 and 3) diagnosed between September 1996 and December 1997 and age-matched controls with a negative Pap obtained during the same time period were selected. RESULTS: Sixty-three cases (mean age = 32 years) of HSIL and 69 controls (mean age = 33 years) constituted the study population. Any prior abnormal diagnosis conferred a 15-fold increased risk of HSIL on the current Pap (50/63 vs. 14/69, P < .0001). When limited to the 60 women with at least three prior Paps, the odds ratio for HSIL on the current Pap with any prior abnormal was 18 (28/31 vs. 10/29, P < .0001). Three cases had at least three consecutive negative Paps prior to the diagnosis of HSIL. CONCLUSION: Women with one or more prior negative Pap smears had a significantly decreased risk of HSIL on the current Pap. Consecutive negative Paps did not appear to further decrease the risk; 10% of HSIL patients had had three or more consecutive prior negative Paps. To detect HSIL at its earliest stage, women should be advised to continue annual Pap screening in spite of consecutive negative results.

Adolescent↗
PubMed2001

[Actin is located in the nucleus and nuclear matrix of HeLa cells].

HeLa cell nuclei were isolated and the nuclear matrix specimens were prepared. After labelled with an anti-actin antibody and FITC-conjugated secondary antibody, both the nuclei and nuclear matrix specimens were observed to emanate specific yellow-green fluorescence. The fluorescent signals in the nuclear matrix were much stronger than that in the nuclei, and the signals in former were widespread throughout the whole structure while that in the latter were mainly defined to their peripheral regions. A 43 kD band was revealed in nuclei and nuclear matrix specimens by SDS-PAGE, and was then proved to be actin by Western blot, confirming the immuno-fluorescence observations. When stained with TRICT-conjugated phalloidin, both the nuclei and nuclear matrix specimens were found to give off specific, red fluorescent signals which represent the location of F-actin (filamentous actin), and the pattern of TRITC signals distribution in the nuclei and nuclear matrix showed similarity with that of FITC signals. The existence and significance of actin and F-actin in the nuclei and nuclear matrix were discussed.

Actins↗
PubMed2001

[Protective effect of erigeron injections on hepatotoxicity induced by intestinal ischemia-reperfusion in mice].

The liver injury was induced by intestinal ischemia-reperfusion and the protective effect of erigeron injection (EI) was studied in mice. The results showed that serum alanine transaminase (ALT) and glutathione S-transferase (GST) activity increased while the root of superior mesenteric artery was blocked with non-injury artery clap for 20 minute and reperfusion for 1 hour. EI could protect the above changes induced by intestinal ischemia-reperfusion. EI could reduce the activities of serum ALT and GST, decrease the content of hepatic MDA and significantly increase the activity of SOD. The pathological changes of hepatocytes induced by intestinal ischemia-reperfusion were less in EI groups. These results suggested that EI could protect the liver of mice from injury induced by intestinal ischemia-reperfusion. One of the mechanisms of hepatoprotective action was related to the antioxidative function of erigeron.

Alanine Transaminase↗
PubMed2001

[Isolation, purification and determination of polysaccharides X-C-3-III and X-C-3-IV from Angelica sinensis (Oliv) Diels].

Polysaccharides X-C-3-III and X-C-3-IV had been obtained from Angelica sinensis (Oliv) Diels. Their average MW were determined to be 85,000 and 65,765 by gel chromatography after the hydrolysates of X-C-3-III and X-C-3-IV, the compositions of them were identified by silanization method and capillary gas chromatography. X-C-3-III and X-C-3-IV are composed of galacose, arabinose, rhamnose, glucuronic acid and galacturonic acid. The molar ratio of those sugars were determined as 24.3:15.8:4.2:3.1:52.6 and 12.6:10.7:7.2:8.3:61.2, respectively.

Angelica sinensis↗
PubMed2001

[Expression of human anti-HBsAg-interferon fusion protein in CHO cells].

OBJECTIVE: To study the possibility of expressing human anti-HBsAg-interferon fusion protein in CHO cells as a putative targeting drug for hepatitis B. METHODS: Both the heavy and light chain genes of human anti-HBsAg antibody derived from a phage display library were fused with alpha-2b interferon (IFN-alpha-2b) gene in vitro by polymerase chain reaction. The IFN alpha-2b gene was placed at the C terminal and a 15 amino acid linker was introduced at the fusion site. The light chain-IFN expression plasmid pLIC was constructed with a mammalian expression vector pcDNA3.1(+) and the heavy chain-IFN expression plasmid pFID was constructed with another mammalian expression vector pCdhfr1. These plasmids and the anti-HBsAg full-length light and heavy chain expression plasmids (pLIC and pHFD, respectively) were transfected into CHO (dhfr-) cells by the following three combinations:I, pLIC + pHFD;II, pLIC + pFID; III, pLFC + pFID. The cultured supernatant of the transfected cells was collected and assayed for IFN activity and HBsAg affinity. RESULTS: The supernatant of combination I and II displayed IFN activity but only combination I supernatant exhibited HBsAg affinity. CONCLUSIONS: The successful expression of a fusion protein with both HBsAg affinity and interferon activity may lead to a new way to make a targeting drug for hepatitis B.

Animals↗
PubMed2001

[Effects of tobacco smoke on the expression of ICAM-1 in human umbilical vein endothelial cells].

OBJECTIVE: To study the effect of tobacco smoke on the expression of intercellular adhesion molecule (ICAM)-1 in endothelial cell. METHODS: Macrophages were challenged in vitro with cigarette smog, and the supernatant was collected at 3 h, 6 h, 12 h and 24 h after tobacco treatment. The tumor necrosis factor-alpha (TNF-alpha) was measured by the ELISA method. Then the human umbilical vein endothelial cells (HUVEC) were incubated with the supernatant from the macrophages stimulated by cigarette smoke allergen. ICAM-1 in the supernatant was detected by the ELISA method. RESULTS: TNF-alpha was increased with the longer incubation time. A significant difference of TNF-alpha(t = -4.301, P < 0.01) was observed between the tobacco treated group (4.967 +/- 0.802 pg/ml) and the control group (3.181 +/- 0.214 pg/ml). Soluble ICAM-1 in HUVEC in the tobacco treated group (mean 0.068 4 ng/ml) increased 49% than the controls (mean 0.045 9 ng/ml). CONCLUSION: The results suggested that cigarette smog enhances the expression of TNF-alpha in the antigen-presenting cell(APC)-macrophage, and the latter up-regulates the secretion of the membrane glycoprotein sICAM-1 in HUVEC which can assist leukocyte immigration.

Cells, Cultured↗
PubMed2001

[Organochlorine residues in eggs of night heron breeding in Yuantouzhu, Wuxi and their functions as bioindicator].

This study analyzed chlorinated pesticides in eggs of night heron breeding in Yuantouzhu, Tai lake. The HCH isomers, DDT, DDD, DDE, endrine and heptachlor epoxide were detected out in egg samples. The residue level and the percent of detection of beta-HCH and p,p'-DDE were significantly high. The mean value of p,p'-DDE was 0.906 microgram/g dry weight. Most of the chlorinated pesticides in samples from Wuxi were higher than those of Gongqing city, Jiangxi province. Oppositely, the hatching rate of night heron egg in Wuxi region was lower than that in Gongqing city. It may be related to the difference of DDE residual levels. Using organochlorine residue in eggs of water-fowls as an indicator for environmental quality assessment is feasible.

Animals↗