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Biomedical subjects

Jun Wang

Publications and source records attributed to Jun Wang.

At least 253 records · Page 14Linked to original sources
PubMed2005

ChickVD: a sequence variation database for the chicken genome.

Working in parallel with the efforts to sequence the chicken (Gallus gallus) genome, the Beijing Genomics Institute led an international team of scientists from China, USA, UK, Sweden, The Netherlands and Germany to map extensive DNA sequence variation throughout the chicken genome by sampling DNA from domestic breeds. Using the Red Jungle Fowl genome sequence as a reference, we identified 3.1 million non-redundant DNA sequence variants. To facilitate the application of our data to avian genetics and to provide a foundation for functional and evolutionary studies, we created the 'Chicken Variation Database' (ChickVD). A graphical MapView shows variants mapped onto the chicken genome in the context of gene annotations and other features, including genetic markers, trait loci, cDNAs, chicken orthologs of human disease genes and raw sequence traces. ChickVD also stores information on quantitative trait loci using data from collaborating institutions and public resources. Our data can be queried by search engine and homology-based BLAST searches. ChickVD is publicly accessible at http://chicken.genomics.org.cn.

Animals↗
PubMed2005

SilkDB: a knowledgebase for silkworm biology and genomics.

The Silkworm Knowledgebase (SilkDB) is a web-based repository for the curation, integration and study of silkworm genetic and genomic data. With the recent accomplishment of a approximately 6X draft genome sequence of the domestic silkworm (Bombyx mori), SilkDB provides an integrated representation of the large-scale, genome-wide sequence assembly, cDNAs, clusters of expressed sequence tags (ESTs), transposable elements (TEs), mutants, single nucleotide polymorphisms (SNPs) and functional annotations of genes with assignments to InterPro domains and Gene Ontology (GO) terms. SilkDB also hosts a set of ESTs from Bombyx mandarina, a wild progenitor of B.mori, and a collection of genes from other Lepidoptera. Comparative analysis results between the domestic and wild silkworm, between B.mori and other Lepidoptera, and between B.mori and the two sequenced insects, fruitfly and mosquito, are displayed by using B.mori genome sequence as a reference framework. Designed as a basic platform, SilkDB strives to provide a comprehensive knowledgebase about the silkworm and present the silkworm genome and related information in systematic and graphical ways for the convenience of in-depth comparative studies. SilkDB is publicly accessible at http://silkworm.genomics.org.cn.

Animals↗
PubMed2005

Capillary array electrophoresis for the research of asymmetric transformation reaction of L-proline to D-proline.

One asymmetric transformation reaction of L-proline (L-Pro) to D-proline was studied by a home-made capillary array electrophoresis (CAE) for the first time. The aldehyde catalysts and the organic acid solvents for the asymmetric transformation reaction were rapidly screened and the enantiomeric excess values of the asymmetric product of L-Pro were directly obtained from the electrophoretogram of CAE.

Aldehydes↗
PubMed2005

Certification of the cadmium content in certified reference materials for Cd rice flour.

The materials used to prepare the certified reference materials (CRMs) for Cd rice flour described here were taken from Cd-contaminated rice samples, round-grained and non-sticky rice grown in different provinces throughout China. The Cd rice materials were first blown to remove dust and husk, and then were successively ground, sieved, dried and mixed to form homogeneous rice flour. The Cd rice flour was packed in glass bottles, each bottle containing 40 g. All bottled CRMs were subjected to 60Co radiation (2.5 megarads) for long-term preservation. Atomic absorption spectrometry was used to determine the homogeneity of the cadmium content in each material. The certification of the cadmium content for the three CRMs was performed using isotope dilution mass spectrometry.

Cadmium↗
PubMed2005

Absolute isotopic composition and atomic weight of neodymium using thermal ionization mass spectrometry.

Synthetic mixtures prepared gravimetrically from highly enriched isotopes of neodymium in the form of oxides of well-defined purity were used to calibrate a thermal ionization mass spectrometer. A new error analysis was applied to calculate the final uncertainty of the atomic weight value. Measurements on natural neodymium samples yielded an absolute isotopic composition of 27.153(19) atomic percent (at.%) 142Nd, 12.173(18) at.% 143Nd, 23.798(12) at.% 144Nd, 8.293(7) at.% 145Nd, 17.189(17) at.% 146Nd, 5.756(8) at.% 148Nd, and 5.638(9) at.% 150Nd, and the atomic weight of neodymium as 144.2415(13), with uncertainties given on the basis of 95% confidence limits. No isotopic fractionation was found in terrestrial neodymium materials.

Hot Temperature↗
PubMed2005

Role of stem cell factor and its receptor in the pathogenesis of pediatric aplastic anemia.

In order to investigate the levels of stem cell factor (SCF) and its receptor c-kit protein and mRNA in pediatric aplastic anemia (AA) and their relevance to the pathogenesis, immunocytochemical and in situ hybridization were utilized to detect the expression of SCF and its receptor c-kit gene protein and mRNA, respectively in 59 children with AA and 51 normal controls. The relationship between SCF and c-kit and the pathogenesis of AA was analyzed subsequently. The results showed that the positive rate of SCF protein and mRNA expression in children with AA was significantly lower than that in healthy controls (P < 0.05). However, there was no significant difference in the positive rate of c-kit protein and mRNA expression between children with AA and control group (P > 0.05). It was concluded that the expression of SCF is significantly decreased in children with AA, which may be closely associated with the pathogenesis of the AA. c-kit may be unrelated to the development of pediatric AA. Therefore, AA in children may have abnormalities at SCF/c-kit signal transduction levels.

Adolescent↗
PubMed2005

Role of beta-adrenergic signal transduction pathway on myocardial ischemic preconditioning of rats.

To study the changes in every part of the beta-adrenergic signal transduction pathway and their effects on ischemic preconditioning of rat myocardium in vivo. SD rats were divided into three groups: IP group, I/R group and CON group. The IP group was further divided into PC1-, 2-, 3-, and PC1+, 2+, 3+ groups according to preconditioning procedure. The rats received surgical procedure and underwent left coronary artery occlusion and reperfusion. We analyzed the infarct size by TTC staining, measured serum myocardial enzymes, studied the beta-AR Bmax and Kd by radioligand binding assay of receptors, checked the activity of AC and PKA by the method of biochemistry and examined the content of cAMP by radioimmunoassay. The infarct area was much smaller in the IP group than in the I/R group (P < 0.001), while the enzymes were significantly higher in I/R (P < 0.001). The Bmax of beta-AR in IP was much higher than that in I/R (P < 0. 001), but no difference in Kd could be seen between IP and I/R groups. In IP, the activity of AC and PKA and the content of cAMP were higher than those in I/R (P < 0.05, 0.002 and 0.001, respectively). In the procedure of preconditioning, the content of cAMP and the activity of PKA showed the characteristic of cyclic fluctuation. Ischemic preconditioning can protect the heart from necrosis and reduce endo-enzyme leakage. The system of beta-adrenergic signal transduction pathway probably takes part in the protection effect of the IP, which might be elicited by the PKA.

Animals↗
PubMed2005

A pilot study of transcription unit analysis in rice using oligonucleotide tiling-path microarray.

As the international efforts to sequence the rice genome are completed, an immediate challenge and opportunity is to comprehensively and accurately define all transcription units in the rice genome. Here we describe a strategy of using high-density oligonucleotide tiling-path microarrays to map transcription of the japonica rice genome. In a pilot experiment to test this approach, one array representing the reverse strand of the last 11.2 Mb sequence of chromosome 10 was analyzed in detail based on a mathematical model developed in this study. Analysis of the array data detected 77% of the reference gene models in a mixture of four RNA populations. Moreover, significant transcriptional activities were found in many of the previously annotated intergenic regions. These preliminary results demonstrate the utility of genome tiling microarrays in evaluating annotated rice gene models and in identifying novel transcription units that will facilitate rice genome annotation.

Carbocyanines↗
PubMed2005

Protein 4.1N does not interact with the inositol 1,4,5-trisphosphate receptor in an epithelial cell line.

Cytosolic Ca2+ regulates a variety of cell functions, and the spatial patterns of Ca2+ signals are responsible in part for the versatility of this second messenger. The subcellular distribution of the inositol 1,4,5-trisphosphate receptor (IP3R) is thought to regulate Ca2+-signaling patterns but little is known about how the distribution of the IP3R itself is regulated. Here we examined the relationship between the IP3R and the cytoskeletal linker protein 4.1N in the polarized WIF-B cell line because protein 4.1N regulates targeting of the type I IP3R in neurons, but WIF-B cells do not express this cytoskeletal protein. WIF-B cells expressed all three isoforms of the IP3R, and each isoform was distributed throughout the cell. These cells did not express the ryanodine receptor. Photorelease of microinjected, caged IP3 induced a rapid rise in cytosolic Ca2+, but the increase began uniformly throughout the cell rather than at a specific initiation site. Expression of protein 4.1N was not associated with redistribution of the IP3R or changes in Ca2+-signaling patterns. These findings are consistent with the hypothesis that the subcellular distribution of IP3R isoforms regulates the formation of Ca2+ waves, and the finding that interactions between protein 4.1N and the IP3R vary among cell types may provide an additional, tissue-specific mechanism to shape the pattern of Ca2+ waves.

Animals↗
PubMed2005

Influence of membrane physical state on lysosomal potassium ion permeability.

Lysosomal permeability to potassium ions is an important property of the organelle. Influence of the membrane physical state on the potassium ion permeability of isolated lysosomes was assessed by measuring the membrane potential with bis(3-propyl-5-oxoisoxazol-4-yl)pentamethine oxonol and monitoring the lysosomal proton leakage with p-nitrophenol. The membrane fluidity of lysosomes was modulated by treatment with membrane fluidizer benzyl alcohol and rigidifier cholesteryl hemisuccinate. Changes in the membrane order were examined by steady-state fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene. The measurements of membrane potential and proton leakage demonstrated that the permeability of lysosomes to potassium ions increased with rigidification of their membranes by cholesteryl hemisuccinate treatment at 37 degrees C, and decreased with fluidization of their membranes by benzyl alcohol treatment at 2 degrees C. The changes in ion permeability could be recovered by fluidizing the rigidified membranes and rigidifying the fluidized membranes. The results suggest that the physical states of lysosomal membranes play an important role in the regulation of their K(+) permeability.

Animals↗
PubMed2005

Human papillomavirus-16 associated squamous cell carcinoma of the head and neck (SCCHN): a natural disease model provides insights into viral carcinogenesis.

Uncertainty regarding the causality of human papillomaviruses (HPVs) in squamous cell carcinoma of the head and neck (SCCHN) necessitates better in vitro models. We carried out molecular analyses of a novel, naturally HPV-16-transformed SCCHN cell line (UPCI:SCC090) and show high copy number of HPV-16 DNA, present in a head to tail, tandemly repeated integrated state. Sequence analysis of the HPV-16 long control region (LCR) in UPCI:SCC090 revealed a deletion of 163 bp, removing a portion of the enhancer sequence, including the binding sites for the transcription factors YY1 and NF1. The E6 and E7 oncogenes of HPV-16 are expressed at high levels in this cell lines, as determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). UPCI:SCC090 contains wild-type tumour suppressor TP53 gene, and undetectable p53 protein, except after treatment with cisplatin, specific proteasome inhibitors or by E6 RNA interference, suggesting E6-dependent degradation of p53 in this cell line. The results of our studies are consistent with a causative role of HPV-16 in the pathogenesis of SCCHN.

Blotting, Southern↗
PubMed2005

Fetuses delivered following preterm prelabor rupture of the membranes are capable of stimulating a proinflammatory response in endothelial cells.

OBJECTIVE: Preterm premature rupture of the membranes (PROM) has been attributed to ascending infection and a choriodecidual inflammatory response (ie, on the maternal side). However, on the fetal side those most at risk of morbidity have a systemic proinflammatory cytokine response. We have recently defined a similar proinflammatory response in pregnancies complicated by vascular disease on the fetal side of the placenta. A factor(s) present in fetal plasma from these pregnancies can stimulate human umbilical vein endothelial cells (HUVECs) to express mRNA for the proinflammatory cytokines, interleukin (IL)-6 and IL-8. The hypothesis of this study was that a similar factor(s) was present in preterm PROM. METHODS: A standard culture of HUVECs was incubated with fetal plasma, obtained immediately following delivery, from normal pregnancies delivering vaginally at term (n=16) and pregnancies delivering following preterm PROM (n=19). Expression of mRNA for IL-6 and IL-8 was assessed by reverse transcription polymerase chain reaction (RT-PCR) and standardized to GAPDH mRNA expression. RESULTS: Endothelial cell expression of IL-6 mRNA (median [25-75th centile] 0.295 [0.252-0.507] vs term vaginal delivery 0.208 [0.151-0.307]; P=.009) was enhanced in response to the fetal plasma from PROM cases compared to pregnancies delivering vaginally at term. In contrast, mRNA expression of IL-8 (median [25-75th centile] preterm PROM 0.41 [0.21-0.78] vs term vaginal delivery 0.49 [0.16-0.68]; P=.46) was not different in the two groups. CONCLUSIONS: We have demonstrated that in fetuses delivered following preterm PROM there is a factor(s) capable of stimulating a local endothelial cell proinflammatory cytokine (IL-6) response. This factor(s) that we have demonstrated may be responsible for the increased cytokine production seen in fetuses with the fetal inflammatory response syndrome.

Endothelium, Vascular↗
PubMed2005

Treatment with nerve growth factor decreases expression of divalent metal transporter 1 and transferrin receptor in PC12 cells.

Divalent metal transporter 1 (DMT1) and transferrin receptor (TfR) might play a key role in non-transferrin-bound iron (NTBI) and transferrin-bound iron (Tf-Fe) uptake by neuronal cells. Recent studies demonstrated that nerve growth factor (NGF)-treated PC12 cells (the neuronal phenotype) have higher NTBI as well as Tf-Fe uptake compared with untreated cells (the undifferentiated cells). We speculated the increased NTBI and Tf-Fe uptake induced by NGF treatment might be associated with the increased expression of DMT1 and TfR. In this study, we investigated the effect of NGF treatment on DMT1 and TfR expression in PC12 cells. Contrary to our expectation, treatment with NGF induced a significant decrease rather than increase in DMT1+IRE, DMT1-IRE and TfR expression in the cells. The data demonstrate that the increase in iron uptake is not associated with the DMT1 and TfR in NGF-treated PC12 cells. The RT-PCR findings of no change in DMT1 mRNA plus our data suggest that regulation of DMT1 expression by NGF might be at the post-transcriptional level.

Animals↗
PubMed2005

Antiviral activity of Cidofovir on a naturally human papillomavirus-16 infected squamous cell carcinoma of the head and neck (SCCHN) cell line improves radiation sensitivity.

High risk HPV types 16 and 18 are associated with cervical cancer and squamous cell carcinoma of the head and neck (SCCHN). Cidofovir is an antiviral drug used to treat HPV-induced laryngeal papillomatosis and other viral infections, with initial reports suggesting activity in cervical carcinoma cells. We investigated the effects of Cidofovir on a naturally HPV-16-transformed SCCHN cell line (UPCI:SCC090), in comparison with a cervical carcinoma cell line (CasKi) of similar viral characteristics, to evaluate its therapeutic potential. HPV-16 gene transcription was only marginally reduced, and the antiviral and p53 restorative effects were modest in SCC90 cells. However, combination with irradiation enhanced the effects of Cidofovir treatment on these cells. Several days of treatment were required for this effect, which may limit its clinical applicability. Future therapies for HPV-associated tumors may include intralesional antiviral therapy in combination with radiation therapy, but optimization for clinical utility is needed.

Adult↗
PubMed2005

A longitudinal study of brain morphometrics using serial magnetic resonance imaging analysis in a canine model of aging.

Longitudinal changes in cortical atrophy, ventricular enlargement, and lesion development in serial MRI scans collected from 47 healthy dogs from 1999 (8-11 years old) to 2002 (11-14 years old) were studied. The first method involved manual region of interest volumetric analysis to examine changes in cerebral and ventricular volume during the three years. No change in cerebral volume was detected but ventricular volume increased significantly each year in 2000, 2001, and 2002. Increased ventricular volume parallels early studies of age-dependent ventricular enlargement in the brain of aging beagle dogs. The second method involved a visual analysis of co-registered serial MRIs for each subject. Consistent with the volumetric results, there was no visible change in cortical thickness indicating no cerebral atrophy, but a significant increase in ventricular size was noted. Visual examination also revealed a significant increase in number of dogs who developed aging lesions over the last 2 years in 2001 and 2002. Additionally, a disproportionate number of lesions were recorded in the frontal cortex and caudate nucleus compared to other brain regions. These lesion findings are consistent with other studies in the aging dog that suggest that the frontal lobes may be particularly vulnerable to age-related changes.

Aging↗
PubMed2005

Sonocatalytic degradation of methyl orange in the presence of TiO2 catalysts and catalytic activity comparison of rutile and anatase.

Rutile and anatase titanium dioxide (TiO(2)) powders were used as sonocatalysts for the degradation of methyl orange which was used as a model compound. Ultrasound was used as an irradiation source. It was found that the sonocatalytic degradation ratios of methyl orange in the presence of TiO(2) powder were much better than ones without any TiO(2), but the sonocatalytic activity of rutile TiO(2) particles was obviously higher than that of anatase TiO(2) particles. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results show that the best degradation ratio of methyl orange can be obtained when the experimental conditions of the initial methyl orange concentration of 10 mg/l, rutile TiO(2) added amount of 500 mg/l, ultrasonic frequency of 40 kHz, output power of 50 W, pH=3.0 and 40 degrees C within 150 min were adopted. In addition, the catalytic activity of reused rutile TiO(2) catalyst was also studied and found to be better than new rutile TiO(2) catalyst sometimes. All experimental results indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO(2) powder was an advisable choice for treating non- or low-transparent organic wastewaters.

Journal Article↗
PubMed2005

Role of Eotaxin-1 (CCL11) and CC chemokine receptor 3 (CCR3) in bleomycin-induced lung injury and fibrosis.

Eotaxin-1/CCL11 and its receptor CCR3 are involved in recruitment of eosinophils to diverse tissues, but their role in eosinophil recruitment in pulmonary fibrosis is unclear. The present study examined the pulmonary expression of CCL11 and CCR3 during bleomycin (blm)-induced lung injury and determined their importance in the recruitment of inflammatory cells and the development of lung fibrosis. In mice, blm induced a marked pulmonary expression of CCL11 and CCR3. Immunostaining for CCR3 revealed that this receptor was not only expressed by eosinophils but also by neutrophils. CCL11-deficient (CCL11(-/-)) mice developed significantly reduced pulmonary fibrosis. Expression of profibrotic cytokines such as transforming growth factor-beta1 was diminished in the absence of CCL11. Furthermore, increased lung expression of CCL11 significantly enhanced blm-induced lung fibrosis and production of profibrotic cytokines. These effects were also associated with an increase of eosinophil and neutrophil pulmonary infiltration. In contrast, mice treated with neutralizing CCR3 antibodies developed significantly reduced pulmonary fibrosis, eosinophilia, neutrophilia, and expression of profibrotic cytokines. Together, these data suggest that CCL11 and CCR3 are important in the pulmonary recruitment of granulocytes and play significant pathogenic roles in blm-induced lung fibrosis.

Animals↗