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Ning Wang

Publications and source records attributed to Ning Wang.

At least 73 records · Page 4Linked to original sources
PubMed2005

SCF(beta-TrCP1) controls Smad4 protein stability in pancreatic cancer cells.

Smad4, also known as deleted in pancreatic carcinoma locus 4 (DPC4), is a critical co-factor in signal transduction pathways activated by transforming growth factor (TGF)-beta-related ligands that regulate cell growth and differentiation. Mutations in Smad4/DPC4 have been identified in approximately 50% of pancreatic adenocarcinomas. Here we report that SCF(beta-TrCP1), a ubiquitin (E3) ligase, is a critical determinant for Smad4 protein degradation in pancreatic cancer cells. We found that F-box protein beta-TrCP1 in this E3 ligase interacted with Smad4 and that SCF(beta-TrCP1) inhibited TGF-beta biological activity in pancreatic cancer cells by decreasing Smad4 stability. Very low Smad4 protein levels in human pancreatic ductal adenocarcinoma cells were observed by immunohistochemistry. By analyzing pancreatic tumor-derived Smad4 mutants, we found that most point-mutated Smad4 proteins, except those within or very close to a mutation cluster region, exhibited higher interaction affinity with beta-TrCP1 and significantly elevated protein ubiquitination by SCF(beta-TrCP1). Furthermore, AsPC-1 and Caco-2, two cancer cell lines harboring Smad4 point mutations, exhibited rapid Smad4 protein degradation due to the effect of SCF(beta-TrCP1). Both Smad4 levels and TGF-beta signaling were elevated by retrovirus-delivered beta-TrCP1 siRNA in pancreatic cancer cells. Therefore, inhibition of Smad4-specific E3 ligase might be a target for therapeutic intervention in pancreatic cancer.

Adenocarcinoma↗
PubMed2005

Sexually transmitted disease/HIV and heterosexual risk among miners in townships of Yunnan Province, China.

The HIV epidemics in some areas of Yunnan Province, southwestern China, are close to becoming generalized, demanding the need for a better understanding of sexually transmitted disease (STD) and heterosexual HIV risk. While female heterosexual risk is captured by sentinel surveillance, less is known about clients of commercial sex workers and other subsets of men at increased risk of STD/HIV. A convenience sample of 232 miners in townships of Yunnan Province completed a questionnaire and provided specimens for STD/HIV testing. Relative prevalences of HIV, gonorrhea, and chlamydia among sexually experienced miners surveyed were 0.5% (1/182), 0.5% (1/182), and 9.3% (17/182), respectively. Chlamydia seropositivity was significantly associated with receiving less education (p = 0.03). Among all respondents, 9.4% admitted to purchasing sex, 82.9% had not used a condom in the last 6 months, and substantial gaps in knowledge about STD/HIV were apparent. Because preventing heterosexual spread of HIV is crucial in this area of China to prevent a generalized epidemic, better understanding and designing low literacy interventions targeted at sex worker clients and similar subsets of high-risk migrants may be warranted.

Adolescent↗
PubMed2005

Heterosexual transmission of HIV in China: a systematic review of behavioral studies in the past two decades.

OBJECTIVE: The objective of this study was to address the role of heterosexual transmission of HIV in China. GOAL: The goal of this study was to explore the prevalence of unsafe sex and the likelihood of HIV spread heterosexually from core populations to others. STUDY: The authors conducted a review of behavioral studies. RESULTS: Drug users were more likely to be involved in higher-risk sexual behaviors than were those who abstained from using drugs. Most female drug users (52-98%) reported having engaged in commercial sex. Most female sex workers (FSWs) and individuals with sexually transmitted diseases (STDs) had concurrent sexual partners. Many continued to have unprotected sex after noticing STD symptoms in themselves or their sexual partners. From 5% to 26% of rural-to-urban migrants had multiple sexual partners and 10% of males patronized FSWs during migration. CONCLUSIONS: Factors such as high rates of FSW patronage, low rates of condom use during commercial sex, having sex with both commercial and noncommercial sexual partners, and high rates of STD infection may promote a heterosexual epidemic in China.

Behavioral Research↗
PubMed2005

The bioreactor with CYP3A4- and glutamine synthetase-introduced HepG2 cells: treatment of hepatic failure dog with diazepam overdosage.

A novel recombinant human hepatic cell line, CYP3A4- and glutamine synthetase (GS, an enzyme which converts ammonium ion and glutamate to glutamine)-introduced HepG2 (HepG2-GS-CYP3A4), was established. Its usefulness in a large-scale culture with a circulatory bioreactor in vitro and in dog models of ischemic hepatic failure with acute diazepam (DZP, a substrate of CYP3A4) overdosage was further examined. HepG2-GS-CYP3A4 expressed about 9 times larger amounts of CYP3A4 protein than a control. After incubation with HepG2-GS-3A4 cells in a circulatory bioreactor for 24 h, ammonia and DZP concentrations in the culture medium significantly decreased by about 40%. Furthermore, this system improved the survival time and decreased serum concentrations of DZP, ammonia, and transaminase in dogs with ischemic hepatic failure plus acute DZP overdosage. The mean survival time with bioreactor with HepG2-GS-3A4 was 42.7 +/- 3.6 h, which was significantly longer than that without reactor, with reactor (no cells), and with HepG2-GS (23.4 +/- 2.8, 22.1 +/- 2.4, and 31 +/- 3.7 h, respectively). Therefore, it is concluded that this bioartificial liver could be a good tool for the treatment of dogs with hepatic failure and that it could potentially be a bridging procedure to liver transplantation.

Animals↗
PubMed2005

A field assessment of long-term laboratory sediment toxicity tests with the amphipod Hyalella azteca.

Response of the amphipod Hyalella azteca exposed to contaminated sediments for 10 to 42 d in laboratory toxicity tests was compared to responses observed in controlled three-month invertebrate colonization exposures conducted in a pond. Sediments evaluated included a sediment spiked with dichlorodiphenyldichloroethane (DDD) or dilutions of a field sediment collected from the Grand Calumet River (GCR) in Indiana (USA) (contaminated with organic compounds and metals). Consistent effects were observed at the highest exposure concentrations (400 microg DDD/goc [DDD concentrations normalized to grams of organic carbon (goc) in sediment] or 4% GCR sediment) on survival, length, and reproduction of amphipods in the laboratory and on abundance of invertebrates colonizing sediments in the field. Effect concentrations for DDD observed for 10-d length and 42-d reproduction of amphipods (e.g., chronic value [ChV] of 66 microg DDD/goc and 25% inhibition concentration [IC25] of 68 microg DDD/ goc for reproduction) were similar to the lowest effect concentrations for DDD measured on invertebrates colonizing sediment the field. Effect concentrations for GCR sediment on 28-d survival and length and 42-d reproduction and length of amphipods (i.e., ChVs of 0.20-0.66% GCR sediment) provided more conservative effect concentrations compared to 10-d survival or length of amphipods in the laboratory or the response of invertebrates colonizing sediment in the field (e.g., ChVs of 2.2% GCR sediment). Results of this study indicate that use of chronic laboratory toxicity tests with H. azteca and benthic colonization studies should be used to provide conservative estimates of impacts on benthic communities exposed to contaminated sediments. Bioaccumulation of DDD by oligochaetes colonizing the DDD-spiked sediment was similar to results of laboratory sediment tests previously conducted with the oligochaete Lumbriculus variegates, confirming that laboratory exposures can be used to estimate bioaccumulation by oligochaetes exposed in the field.

Amphipoda↗
PubMed2005

[RT-PCR detecting NUP98-HOX fusion gene in leukemia].

To investigate whether there are NUP98-HOXA, NUP98-HOXB, NUP98-HOXC, NUP98-HOXD fusion genes in leukemia patients in Xinjiang, cellular total RNA was extracted from the bone marrow mononuclear cells, the formaldehyde-agarose gel electrophoresis was used to judge whether RNA was intact, the 17 RT-PCR primers were designed to amplify the predicted fusion junctions and 412 bp GAPDH was used as an internal control, NUP98-HOXA fusion genes were amplified by nested-PCR following reverse transcription. One-step PCR was performed to amplify the other predicted fusion genes. The results showed that RNA was proved to be intact and expression of GAPDH was found in every sample. However, no predicted fusion transcripts were detected in leukemia patients. In conclusion, no NUP98-HOX fusion genes were detected in the samples from Xinjiang.

Adult↗
PubMed2005

[Effect of synthesis conditions on the morphology and binding property of (-)-ephedrine imprinted polymers].

Contribution of the synthesis parameters to the properties of the polymer is one of the major interests in the study of molecular imprinting technology. To have a better understanding of the influence of polymerization conditions on the polymer morphology and binding property, (-)-ephedrine imprinted polymers synthesized with different cross-linkers (ethylene glycol dimethacrylate (EDMA) and pentaerythritol triacrylate (PETRA)), porogens (chloroform and acetonitrile) and monomer concentrations were compared. The resulting polymers were characterized with their pore structure, texture and binding affinities by BET and equilibrium adsorption method. The selectivity of the polymer was evaluated with chromatographic analysis. The results suggested that CHCl3 is a good solvent for methacrylic acid (MAA)-EDMA and MAA-PETRA polymer chains which resulted in smaller polymer surface area. Quantitative determinations of the carboxyl groups in the polymer indicated that polymers synthesized with the same pre-polymerization composition except porogen can have different concentrations of functional monomer in their structures. The study showed that porogen in the molecular imprinting synthesis can affect the morphology and composition of the polymers, which influence the binding affinity of the polymers.

Acetonitriles↗
PubMed2005

Rapid diagnosis of spinal muscular atrophy using denaturing high-performance liquid chromatography.

OBJECTIVE: To introduce the application of denaturing high-performance liquid chromatography (DHPLC) in the diagnosis of childhood type spinal muscular atrophy (SMA). METHODS: Exon 7 and flanking area of survival motor neuron (SMN) gene were amplified by PCR in 1 standard sample, 25 normal individuals and 25 patients with SMA. The PCR products were then directly loaded onto the DHPLC system after denaturing and annealing. Different DNA segments were separated by changing the concentration of buffer A relative to that of buffer B. RESULTS: Different DNA segments were separable on the DHPLC chromatogram. Three peaks including SMN1/SMN2 heteroduplex peak, SMN2 homoduplex peak and SMN1 homoduplex peak were detected in 23 out of 25 normal individuals. Only SMN1 homoduplex peak was detected in 2 normal individuals and the standard sample, indicating the deletion of SMN2 On the contrary, only the SMN2 homoduplex peak was detected in 22 out of 25 patients with SMA, indicating deletion of SMN1. The three peaks as those of normal individuals were detected in the other 3 patients, indicating no SMN1 or SMN2 deletion. CONCLUSION: As a new technology for diagnosing SMA, DHPLC is sensitive, accurate, rapid and convenient.

Chromatography, High Pressure Liquid↗
PubMed2005

[The epidemiological study on human immunodeficiency virus infection among paid blood donors living in Shandong provincial China Comprehensive Response Project Areas].

OBJECTIVE: To understand the current epidemic situation and high risk factors of human immunodeficiency virus (HIV) infection among paid blood donors living in Shandong provincial China Comprehensive Response (CARES) Project Areas. METHODS: All residents between 20 to 60 years old were selected from one or several counties in August 2003. RESULTS: There were 19 HIV(+) infections among 661 subjects interviewed. HIV prevalence rate among paid blood donors was higher (3.98%) than that of others (0.48%) while HIV prevalence rate was higher in plasma donors (7.24%) than that in both plasma and full blood donors (2.90%). There was no infections identified in full blood donors. Donors who donated blood during 1994 - 1995 had a higher prevalence rate (7.07%) than those who started donation after 1995 and those began donation before 1993 (0.99%). The rate of condom use was lower among paid blood donors (13.72%) than that of others. There was a lower rate of voluntary HIV testing among paid blood donors than that of others. CONCLUSION: The main high risk population of HIV infection were paid donors in CARES Project Areas, whose risk factor was plasma donation and were infected mainly before 1995. Both the rate of condom use and HIV testing were all very low, indicating that they knew little on HIV/AIDS and paid less attention to self-proctection. It is necessary to enhance HIV/AIDS health education and behavior intervention on paid blood donors.

Adult↗
PubMed2005

[Cloning and analysis of psaB cDNA of Dunaliella salina].

One pair of degenerate primer was designed according to conserved motifs of the psaB (A2 subunit of photosystem I) of Chlamydomonas reinhardtii, Chlamydomonas moewusii, Chlorella vulgaris and Mesostigma viride, and a total RNA of Dunaliella salina (D. salina) was extracted with TRIzol reagent. A cDNA fragment, about 1.8kb in length, from green algal D. salina was obtained through RT-PCR method. The resulting PCR product was cloned into T-vector and screened to determine its sequence. Homologous analysis of the deduced amino acid sequence was performed by BLAST and subsequeqtly compared with GenBank data. The obtained cDNA sequence was 1815 bp long, which encodes 605 amino acids (GenBank accession number: AY820754). The sequence shared high homologue with the following psaB: Chlamydomonas reinhardtii 92%, Chlamydomonas moewusii 91%, Chlorella vulgaris 86%, Mesostigma viride 85%, Physcomitrella patens subsp. Patens 85% and Nephroselmis olivacea 84%. It can be concluded that the cloned sequence is psaB cDNA fragment from D. salina.

Algal Proteins↗
PubMed2005

[The effect of tetrandrine on the expression of the P170, LRP and TOPO II in S180's tumor cell induced by chemotherapy in the mice with acquired multi-drug resistance].

OBJECTIVE: To observe the effect of tetrandrine on the P170 production expressed by multi-drug resistance gene, lung resistant protein (LRP), and topoisomeras II and elucidate the underlying molecular mechanism. METHOD: Cellular model of multi-drug resistance was established in S180 tumor cell by means of the scheme of PFC chemotherapy at the dosage lower than that with curative effect. P170, LRP and TOPO II were measured by flow cytometry after the mouse model was treated with tetrandrine for 4 weeks. RESULT: tetrandrine obviously reduced the enhancement of express of P170, LRP and the activity of TOPO II in the tumor cells with multi-drug resistance induced by chemotherapy. CONCLUSION: Tetrandrine significantly inhibits the multi-drug resistance of tumor cells induced by chemotherapy via diminishing both the expression of multi-drug resistance gene and the activity of topoisomeras II.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

Quantitative studies on SMN1 gene and carrier testing of spinal muscular atrophy.

OBJECTIVE: To construct a method for detecting the copy number of survival of motor neuron 1 gene (SMN1) with single copy difference based on real-time fluorescence quantitative PCR, and to make practical use of the method for acquiring the data on SMN1 copy number in Chinese as well as for screening the carriers of spinal muscular atrophy (SMA) from healthy individuals and SMA families. METHODS: Exon 7 and flanking area of SMN1 gene were amplified by real-time fluorescence quantitative PCR in 264 healthy individuals, in 1 standard sample having 2 SMN1 but having no SMN2, and in 88 parents of SMA patients. The samples for detecting were diluted to 30 ng/microL and the standard sample was diluted to 15 ng/microL, 30 ng/microL, 45 ng/microL, 60 ng/microL; the unknown samples and 4 standard samples with different concentrations were amplified at the same time, a standard curve could be drawn out according to the results of the 4 standard samples, then the copy number of samples could be calculated. RESULTS: Of 88 parents' samples, 84 samples each had 1 copy of SMN1, and the rest 4 each had 2 copies of SMN1. Of 264 healthy individuals' samples, 5 samples each had only 1 copy of SMN1 (an indicator of definite gene carriers), 232 samples each had 2 copies of SMN1, 25 samples each had 3 copies of SMN1, and 2 samples each had 4 copies of SMN1. Of the samples of 32 members of SMA families, 2 samples each had only 1 copy of SMN1 indicating definite gene carriers, 25 samples each had 2 copies of SMN1, and 5 samples each had 3 copies of SMN1. CONCLUSION: SMN1 copy number could be detected precisely by real-time fluorescence quantitative PCR; the screening of gene carriers could provide essential data for genetic counseling.

Exons↗
PubMed2005

Genetic variation at nine short tandem repeat loci among islanders of the eastern Adriatic coast of Croatia.

We have analyzed the extent of genetic variation at nine autosomal short tandem repeat loci (D3S1358, VWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, D7S820) among six populations from Croatia: five distributed in the islands of the eastern Adriatic coast and one from the mainland. The purpose is to investigate the usefulness of these loci in detecting regional genetic differentiation in the studied populations. Significant heterogeneity among the island and mainland populations is revealed in the distributions of allele frequencies; however, the absolute magnitude of the coefficient of gene differentiation is small but significant. The summary measures of genetic variation, namely, heterozygosity, number of alleles, and allele size variance, do not indicate reduced genetic variation in the island populations compared to the mainland population. In contrast to the two measures of genetic variation, allele size variance and within-locus heterozygosity, the imbalance index (beta) indicates evidence of recent expansion of population sizes in all islands and in the mainland. High mutation rates of the studied loci together with local drift effects are likely explanations for interisland genetic variation and the observed lack of reduced genetic diversity among the island populations.

Alleles↗
PubMed2005

[A cross-sectional survey on hepatitis C virus infection among residents aged 18-59 years in a former commercial blood donating community, Shanxi Province].

OBJECTIVE: To determine sero-prevalence of and risk factors for hepatitis C virus infection (HCV) among residents aged 18-59 years in a former commercial blood donating community, Shanxi province. METHODS: A community-based cross-sectional survey was conducted among 660 randomly selected residents aged 18-59 years from 12 villages in a rural county of Shanxi province. Structured questionnaire was administered to collect socio-demographic,medical and risk behavioral information. 7 ml-volume venous blood was collected for HCV antibody testing. RESULTS: The overall HCV sero-prevalence rates were 8.2% and 27.7% among former commercial blood donors in the community. Data from multivariate logistic regression analysis showed that people ever selling blood (adjusted OR = 14.28, 95% CI: 6.83-29.87) and receiving blood transfusion (adjusted OR = 8.66,95% CI: 2.31-32.47) were the primary risk factors for HCV infection. Subgroup analysis in blood donors explored that ever selling plasma (adjusted OR = 8.56,95% CI: 2.87-25.54) was the risk factor for HCV infection. Villagers who stopped selling blood in 1994 and thereafter were less likely to be HCV positive than those stopping selling blood before 1994 (adjusted OR = 0.32,95% CI: 0.11-0.93). Female donors had a lower risk than male ones (adjusted OR = 0.28, 95% CI: 0.10-0.83). CONCLUSION: A HCV epidemic was once existing in rural community residents in the province that former commercial blood/plasma donation was the main reason for HCV epidemic in the community. It is urgent to make efficient measures to prevent HCV secondary transmission and provide patients with care and treatment to this community.

Adolescent↗
PubMed2004

Inhibition of small-intestinal sugar absorption mediated by sodium orthovanadate Na3VO4 in rats and its mechanisms.

AIM: To investigate the inhibitory effects of sodium orthovanadate on small-intestinal glucose and maltose absorption in rats and its mechanism. METHODS: Normal Wistar rats were lavaged with sodium orthovanadate (16 mg/kg, 4 mg/kg and 1 mg/kg) for 6 d. Blood glucose values were measured after fasting and 0.5, 1, 1.5 and 2 h after glucose and maltose feeding with oxidation-enzyme method. alpha-glucosidase was abstracted from the upper small intestine, and its activity was examined. mRNA expression of alpha-glucosidase and glucose-transporter 2 (GLUT2) in epithelial cells of the small intestine was observed by in situ hybridization. RESULTS: Sodium orthovanadate could delay the increase of plasma glucose concentration after glucose and maltose loading, area under curve (AUC) in these groups was lower than that in control group. Sodium orthovanadate at dosages of 10 micromol/L, 100 micromol/L and 1000 micromol/L could suppress the activity of alpha-glucosidase in the small intestine of normal rats, with an inhibition rate of 68.18%, 87.22% and 91.91%, respectively. Sodium orthovanadate reduced mRNA expression of alpha-glucosidase and GLUT2 in epithelial cells of small intestine. CONCLUSION: Sodium orthovanadate can reduce and delay the absorption of glucose and maltose. The mechanism may be that it can inhibit the activity and mRNA expression of alpha-glucosidase, as well as mRNA expression of GLUT2 in small intestine.

Animals↗
PubMed2004

Synthesis and application of molecularly imprinted polymer on selective solid-phase extraction for the determination of monosulfuron residue in soil.

A novel sample clean-up procedure using molecularly imprinted polymer as the solid-phase extraction material for the determination of monosulfuron residue in soil samples has been developed. The molecularly imprinted polymer (MIP) was synthesized by non-covalent method with monosulfuron as the template. The selectivity and affinity of the MIP was evaluated by equilibrium adsorption and HPLC experiments, which demonstrated that the MIP has specific affinity for the template. The template-MIP interaction was studied by investigating the influence of different mobile phases on the retention of the template, which provided basic knowledge for the selection of the washing and elution solutions in the molecularly imprinted solid-phase extraction (MISPE) process. The study indicated that polar organic solvents with hydrogen bonding abilities have stronger eluting strength for the monosulfuron. After the MISPE procedure, a clean baseline was obtained in the HPLC quantification analysis. The recoveries of the method using the combination of MISPE and HPLC were above 93% and the R.S.D. was less than 3.2% in the soil sample determinations. Low detection limit (0.08 microg g(-1), when defined as 3 times of the noise) was also obtained in the method evaluation study.

Chromatography, High Pressure Liquid↗
PubMed2004

Proteomic characterization of two snake venoms: Naja naja atra and Agkistrodon halys.

Snake venom is a complex mixture of proteins and peptides, and a number of studies have described the biological properties of several venomous proteins. Nevertheless, a complete proteomic profile of venom from any of the many species of snake is not available. Proteomics now makes it possible to globally identify proteins from a complex mixture. To assess the venom proteomic profiles from Naja naja atra and Agkistrodon halys, snakes common to southern China, we used a combination strategy, which included the following four different approaches: (i) shotgun digestion plus HPLC with ion-trap tandem MS, (ii) one-dimensional SDS/PAGE plus HPLC with tandem MS, (iii) gel filtration plus HPLC with tandem MS and (iv) gel filtration and 2DE (two-dimensional gel electrophoresis) plus MALDI-TOF (matrix-assisted laser desorption ionization-time-of-flight) MS. In the present paper, we report the novel identification of 124 and 74 proteins and peptides in cobra and viper venom respectively. Functional analysis based upon toxin categories reveals that, as expected, cobra venom has a high abundance of cardio- and neurotoxins, whereas viper venom contains a significant amount of haemotoxins and metalloproteinases. Although approx. 80% of gel spots from 2DE displayed high-quality MALDI-TOF-MS spectra, only 50% of these spots were confirmed to be venom proteins, which is more than likely to be a result of incomplete protein databases. Interestingly, these data suggest that post-translational modification may be a significant characteristic of venomous proteins.

Agkistrodon↗