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Biomedical subjects

Jing Wang

Publications and source records attributed to Jing Wang.

At least 199 records · Page 11Linked to original sources
PubMed2006

[Establishing the linkage disequilibrium pattern for the all-trans-retinol dehydrogenase (RDH8) gene].

OBJECTIVE: As part of an on-going effort to map genes involved in complex eye diseases, myopia in particular, single nucleotide polymorphisms (SNPs) and linkage disequilibrium (LD) pattern were used to identified the gene within and around the All-trans-retinol dehydrogenase (RDH8). METHODS: Denaturing high-performance liquid chromatography (DHPLC) was used to screen SNPs in 4 DNA pools each consisting of DNA from five individuals, and genotypes identified SNPs coupled with DNA pooling strategy were performed in 150 Chinese subjects from Hong Kong. The identified common SNPs were included in LD and haplotype analysis using the Haploview2.05 and EH programs. RESULTS: Fifteen SNPs were identified: 7 were common with the minor allele frequency > 0.05, and 10 were novel. Four SNPs in the 3' region exhibited significant LD (/|D'/ > 0.75 and its confidence interval suggesting strong LD, r2 > 0.33, P < 0.031) and formed a haplotype block while 3 common SNPs in the 5' region did not exhibit obvious LD. CONCLUSION: The block-like LD pattern existed around the RDH8 gene region suggest that one SNP (RDH8E5a probably) in the 3' region and at least 2 SNPs in the 5' region (RDH851 particularly) were needed in association studies involving RDH8.

Alcohol Oxidoreductases↗
PubMed2006

[Detection of mtDNA*LHON G11778A mutation by real-time polymerase chain reaction using TaqMan-MGB probe technology].

OBJECTIVE: To develop a simple, rapid and reliable real-time PCR assay based on TaqMan technology using a new MGB probe for detecting mtDNA(*)LHON G11778A mutation and heteroplasmy directly. METHODS: Twenty patients with suspicion of Leber hereditary optic neuropathy (LHON) and their maternal relatives had undergone molecular genetic evaluation. Seventeen normal individuals were used as the controls. A real-time PCR involved two MGB probes (wild-type and mutation-type) in a single tube on the iCycler IQ real-time detection system was used to detect the mtDNA(*)LHON G11778A mutation. The results were then compared with the DNA sequence analysis of the PCR products. A linear standard curve was obtained by pUCm LHON-G and pUCm LHON-A clone. RESULTS: In the controls (wild type), the reaction of VIC-labeled MGB probe was positive and the channel of FAM reaction was negative, the DNA sequence was 100% matched to previously published data. In 20 LHON patients and their maternal relatives, 12 cases showed mutations in DNA sequence analysis, all of them were LHON mtDNA mutation. While 5 other cases showed the combination of LHON mtDNA mutation and wide type gene phenotype, the rate of Ct value in wild type versus gene mutation was over 25%. DNA sequence analysis showed 8 of LHON mtDNA belonged to wild types and 3 cases were heteroplasmy, and the rate of Ct value in gene mutation versus wild type was lower than 25%. CONCLUSION: This real-time PCR assay is a simple, rapid and reliable method for the detection of genotyping mtDNA mutations as well as for quantifying heteroplasmy.

DNA, Mitochondrial↗
PubMed2006

[Study on interaction of anionic surfactant SDS and bovine serum albumin by fourier transform infrared spectroscopy].

FTIR spectroscopy was applied to investigate the interaction of anionic surfactant Sodium Dodecyl Sulfate (SDS) and Bovine Serum Albumin (BSA). Amide band I of BSA was analyzed to obtain the change in secondary structure of BSA when different concentration of SDS was added and during different interaction period. In short interaction period and at low concentration of SDS, the alpha-helixes increased and the random coil decreased. In long interaction period or at high concentration of SDS, SDS unfolded the protein by decreasing the alpha-helix structure and increasing the random coil.

Animals↗
PubMed2005

Bispecific and human disease-related anti-keratin rabbit monoclonal antibodies.

Rabbit antibodies may have favorable properties compared to mouse antibodies, including high affinities and better antigen recognition. We used a biochemical and reverse immunologic approach to generate and characterize rabbit anti-phospho-keratin and anti-keratin monoclonal antibodies (MAb). Human keratins 8 and 18 (K8/K18) were used as immunogens after isolation from cells pretreated with okadaic acid or pervanadate to promote Ser/Thr or Tyr hyperphosphorylation, respectively. Selected rabbit MAb were tested by immunofluorescence staining, immunoprecipitation, and 2-dimensional gels. Keratin phospho and non-phospho-mutants were used for detailed characterization of two unique antibodies. One antibody recognizes a K8 G61-containing epitope, an important epitope given that K8 G61C is a frequent mutation in human liver diseases. This antibody binds K8 that is not phosphorylated on S73, but its binding is ablated by G61 but not S73 mutation. The second antibody is bispecific in that it simultaneously recognizes two epitopes: one phospho (K8 pS431) conformation-independent and one non-phospho conformation-dependent, with both epitopes residing in the K8 tail domain. Therefore, a reverse immunologic and biochemical approach is a viable tool for generating versatile rabbit MAb for a variety of cell biologic applications including the potential identification of physiologic phosphorylation sites.

Animals↗
PubMed2005

[Immediate breast reconstruction with DIEP flap following modified radical mastectomy].

OBJECTIVE: To review the experience in immediate breast reconstruction with DIEP flap following modified radical mastectomy. METHODS: From 2003 to 2005, eight patients with breast cancer have undergone modified radical mastectomy and immediate breast reconstruction with deep inferior epigastric perforator flap. Six patients had stage I disease and 2 patients had stage II disease. RESULTS: The flaps in all the cases survived. Two occurred minor complications. A small part of venous congestion occurred in one flap. One patient had hematoma under the flap. Follow up more than 6 months, no evidence of recurrence and metastasis occurs. Postoperative abdominal wall examination didn't reveal and hernia and bulging. Patient satisfaction with the reconstructed breast was rated high. The reconstructed breast achieved good results in shape, colour and symmetry. CONCLUSION: The procedure introduced is an ideal method for breast reconstruction after modified radical mastectomy.

Adult↗
PubMed2005

Expression of urokinase-type plasminogen activator receptor is correlated with metastases of lingual squamous cell carcinoma.

Lingual squamous cell carcinoma is common and the survival rate is relatively low. The invasion of cancer cells from the primary tumour into the surrounding tissue is an early step in the process of metastasis and urokinase-type plasminogen activator receptor (uPAR) is a vital mediator of cellular migration in some carcinomas. By binding urokinase-type plasminogen activator, uPAR localises proteolytic activity to the leading edge of the cells, thereby facilitating cellular migration and penetration through tissue boundaries. uPAR also binds directly to vitronectin and associates with integrins within the plasma membrane, which alters the strength of cellular adhesion. In this study we used reverse transcription polymerase chain reaction, immunocytochemistry, and Western-blot to examine the expression of uPAR mRNA and protein in Ts and Tca 8113 cell lines of lingual squamous cell carcinoma and in normal oral mucosal cells. uPAR mRNA and protein were expressed in Ts cells, but not in Tca 8113 cells or in normal oral epithelial cells. Ts cells have higher metastatic potential than Tca 8113 cells. The results suggest that uPAR has an important role in the aggressiveness of lingual squamous cell carcinoma.

Blotting, Western↗
PubMed2005

A disposable microfluidic cassette for DNA amplification and detection.

A pneumatically driven, disposable, microfluidic cassette comprised of a polymerase chain reaction (PCR) thermal cycler, an incubation chamber to label PCR amplicons with up-converting phosphor (UPT) reporter particles, conduits, temperature-activated, normally closed hydrogel valves, and a lateral flow strip, was constructed and tested. The hydrogel valves, which were opened and closed with the aid of electrically controlled thermoelectric units, provided a simple means to seal the PCR reactor and suppress bubble formation. The hydrogel-based flow control was electronically addressable, leakage-free, and biocompatible. To test the device, a solution laden with genomic DNA isolated from B. cereus was introduced into the microfluidic cassette and a specific 305 bp fragment was amplified. The PCR amplicons were labelled with the phosphor (UPT) reporter particles, applied to the lateral flow strip, bound to pre-immobilized ligands, and detected with an IR laser that scanned the lateral flow strip and excited the phosphor (UPT) particles that, in turn, emitted light in the visible spectrum. The UPT particles do not bleach, they provide a permanent record, and they readily facilitate the filtering of background noise. The cassette described herein will be used for rapid testing at the point of care.

Hydrogel, Polyethylene Glycol Dimethacrylate↗
PubMed2005

Human cytomegalovirus inhibits Akt-mediated eNOS activation through upregulating PTEN (phosphatase and tensin homolog deleted on chromosome 10).

OBJECTIVES: Atherosclerosis is the leading cause of death in the United States, and human cytomegalovirus (HCMV) infection may play a role in the development of this disease. Diminished expression and/or activity of endothelial nitric oxide synthase (eNOS) are an early event in atherogenesis. In the current study, we investigated the effects of HCMV infection on eNOS activation in human aortic endothelial cells (HAECs). METHODS AND RESULTS: We found that HCMV inhibited eNOS phosphorylation/activation in HAECs. The signaling upstream of eNOS involving Akt and PDK1 were also suppressed by the HCMV infection. Moreover, HCMV infection increased the expression of PTEN (phosphatase and tensin homolog deleted on chromosome 10). Silencing PTEN expression with specific siRNA reversed the inhibitory effects on eNOS activation in HCMV-infected cells indicating the involvement of PTEN in mediating HCMV's inhibitory effects. Next we observed that the activation of p38 MAPK stress signaling pathway mediates HCMV's effects on PTEN up-regulation and eNOS inactivation. CONCLUSIONS: In summary, our findings suggest that inhibition of eNOS leading to endothelial dysfunction may be a basis of the pro-atherogenic effects of HCMV. Importantly, upregulation of PTEN and activation of stress signal p38 MAPK are involved in HCMV's inhibitory effects on eNOS activation.

3-Phosphoinositide-Dependent Protein Kinases↗
PubMed2005

Thin endometrial echo complex on ultrasound does not reliably exclude type 2 endometrial cancers.

OBJECTIVE: The objective of this study was to determine the ultrasonographic characteristics of the uterus and endometrial echo-complex (EEC) of postmenopausal patients diagnosed with type 2 endometrial cancer, including uterine papillary serous carcinoma (UPSC), clear cell carcinoma (CCC), and other endometrial high-grade carcinomas (HGC). METHODS: Postmenopausal patients with type 2 endometrial cancer who underwent preoperative pelvic ultrasound were identified. Histologic diagnoses were made by biopsy or hysterectomy. Ultrasound reports were abstracted for the following parameters: EEC thickness, presence of intracavitary fluid or lesion, myometrial mass, uterine size, and adnexal mass. Ultrasound films were re-reviewed by a single gynecologic ultrasonographer. RESULTS: Fifty-two patients with detailed ultrasound reports comprised the study population. Twenty-six films were available for re-review and inter-examiner agreement was 92%. Forty-four women (85%) presented with abnormal vaginal bleeding. Thirty-four patients (65%) had a thickened EEC measuring >5 mm. In 9 cases (17%), the EEC measured <4 mm. In an additional 9 patients (17%) the EEC was indistinct. One or more other ultrasound abnormalities were found in each of the 18 cases with a non-thickened EEC: intracavitary fluid or lesion (8; 44%), myometrial mass (12; 67%), enlarged uterus (13; 72%), or adnexal mass (5; 28%). CONCLUSION: A thin or indistinct endometrial stripe, especially when associated with other ultrasound abnormalities does not reliably exclude type 2 endometrial cancer. Postmenopausal vaginal bleeding requires endometrial sampling despite a thin EEC in the presence of other ultrasonographic abnormalities or persistent bleeding.

Adnexa Uteri↗
PubMed2005

Stimulating lymphotoxin beta receptor on the dendritic cells is critical for their homeostasis and expansion.

The increased number of dendritic cells (DCs) inside lymphoid tissue may contribute to the enhanced priming of lymphocytes. The homeostasis of splenic DCs has mostly been attributed to their migration to the spleen via the chemokine microenvironment induced by lymphotoxin beta receptor (LTbetaR) signaling on splenic stromal cells. In this study we show that the lack of direct LTbetaR signaling on DCs is associated with the reduction of the number of DCs in the spleen independently of chemokine gradients. LTbetaR-/- mice have reduced DCs and reduced BrdU incorporation on DCs, and fewer DCs from LTbetaR-/- mice are detected in the spleen. Furthermore, increased expression of LIGHT (homologous to lymphotoxin, exhibits inducible expression, competes with herpesvirus glycoprotein D for herpes virus entry mediator on T cells) on T cells, a member of the TNF family (TNFSF14) and a ligand for LTbetaR, could dramatically increase the number of T cells and DCs, which leads to severe autoimmune diseases in a LTbetaR-dependent fashion. In vitro, LIGHT could directly promote accumulation of bone marrow-derived DCs. Furthermore, intratumor expression of LIGHT can dramatically expand DCs in situ, and inoculation of DCs into tumor tissues enhanced tumor immunity. Therefore, LTbetaR signaling on DCs is required for their homeostasis during physiology and pathological conditions, and increased LIGHT-LTbetaR interaction could stimulate DC expansion for T cell-mediated immunity.

Animals↗
PubMed2005

Regulation of endothelial nitric oxide synthase by small RNA.

Repeats (27-nt) in intron 4 have been shown to play a cis-acting role in endothelial nitric oxide synthase (eNOS) promoter activity. We hypothesize that the 27-nt repeats could be the source of small nuclear RNA specifically regulating eNOS expression. In this study, we used synthesized 27-nt RNA duplex and found that the eNOS gene transcriptional efficiency was reduced 63% (0.047 +/- 0.009 vs. 0.126 +/- 0.015, P < 0.01) by nuclear run-on assay. In endothelial cells transfected with the 27-nt small RNA duplex, we found that the eNOS mRNA and protein levels were decreased by >64% (P < 0.01). Conversely, a randomly selected 27-nt from luciferase gene had no effect on the eNOS expression. Furthermore, this eNOS silencing effect appeared to be reversible under the stimulation of vascular endothelial growth factor (10 ng/ml), which is known to up-regulate eNOS expression. Using in situ hybridization and Northern blotting, we observed the presence of endogenous eNOS intron 4-derived 27-nt small RNA, which was confined to the nucleus. In summary, we demonstrated that intron-based microRNAs in eNOS can induce significant gene specific transcriptional suppression, which could be an effective negative feedback regulator for gene expression.

Cells, Cultured↗
PubMed2005

Diffusion of hydrosilanes from the control layer to the vinylsilane-rich flow membrane during the fabrication of microfluidic chips.

During the fabrication of poly(dimethylsiloxane) (PDMS)-based microfluidic chips, polymethylhydrosiloxane (PMHS) species in the control layer diffuse into the flow membrane, which contains polymethylvinylsiloxane (PMVS), and the components cross-link together to form the mechanically enhanced membrane. The diffusion course was investigated by using attenuated total reflectance FTIR and the improvement of mechanical properties of the flow membrane was studied by measuring the Young's modulus and the tensile strength.

Journal Article↗
PubMed2005

Genome dynamics and diversity of Shigella species, the etiologic agents of bacillary dysentery.

The Shigella bacteria cause bacillary dysentery, which remains a significant threat to public health. The genus status and species classification appear no longer valid, as compelling evidence indicates that Shigella, as well as enteroinvasive Escherichia coli, are derived from multiple origins of E.coli and form a single pathovar. Nevertheless, Shigella dysenteriae serotype 1 causes deadly epidemics but Shigella boydii is restricted to the Indian subcontinent, while Shigella flexneri and Shigella sonnei are prevalent in developing and developed countries respectively. To begin to explain these distinctive epidemiological and pathological features at the genome level, we have carried out comparative genomics on four representative strains. Each of the Shigella genomes includes a virulence plasmid that encodes conserved primary virulence determinants. The Shigella chromosomes share most of their genes with that of E.coli K12 strain MG1655, but each has over 200 pseudogenes, 300 approximately 700 copies of insertion sequence (IS) elements, and numerous deletions, insertions, translocations and inversions. There is extensive diversity of putative virulence genes, mostly acquired via bacteriophage-mediated lateral gene transfer. Hence, via convergent evolution involving gain and loss of functions, through bacteriophage-mediated gene acquisition, IS-mediated DNA rearrangements and formation of pseudogenes, the Shigella spp. became highly specific human pathogens with variable epidemiological and pathological features.

DNA Transposable Elements↗
PubMed2005

Adsorption and conformation of carboxymethyl cellulose at solid-liquid interfaces using spectroscopic, AFM and allied techniques.

Carboxymethyl cellulose (CMC) is a polysaccharide which is widely used in many industrial sectors including food, textiles, paper, adhesives, paints, pharmaceutics, cosmetics and mineral processing. It is a natural organic polymer that is non-toxic and biodegradable. These properties make it ideal for industrial applications. However, a general lack of understanding of the interaction mechanism between the polysaccharides and solid surfaces has hindered the application of this polymer. In this work, adsorption of CMC at the solid-liquid interface is investigated using adsorption and electrophoretic mobility measurements, FTIR, fluorescence spectroscopy, AFM and molecular modeling. CMC adsorption on talc was found to be affected significantly by changes in solution conditions such as pH and ionic strength, which indicates the important role of electrostatic force in adsorption. The pH effect on adsorption was further proven by AFM imaging. Electrokinetic studies showed that the adsorption of CMC on talc changed its isoelectric point. Further, molecular modeling suggests a helical structure of CMC in solution while it is found to adsorb flat on the solid surface to allow its OH groups to be in contact with the surface. Fluorescence spectroscopy studies conducted to investigate the role of hydrophobic bonding using pyrene probe showed no evidence of the formation of hydrophobic domains at talc-aqueous interface. Urea, a hydrogen bond breaker, markedly reduced the adsorption of CMC on talc, supports hydrogen bonding as an important factor. In FTIR study, the changes to the infrared bands, associated with the CO stretch coupled to the CC stretch and OH deformation, were significant and this further supports the strong hydrogen bonding of CMC to the solid surface. In addition, Langmuir modeling of the adsorption isotherm suggests hydrogen bonding to be a dominant force for polysaccharide adsorption since the adsorption free energy of this polymer was close to that for hydrogen bond formation. All of the above results suggest that the main driving forces for CMC adsorption on talc are a combination of electrostatic interaction and hydrogen bonding rather than hydrophobic force.

Adsorption↗
PubMed2005

Pharmacokinetics, toxicity of nasal cilia and immunomodulating effects in Sprague-Dawley rats following intranasal delivery of thymopentin with or without absorption enhancers.

Thymopentin (TP 5), a synthetic pentapeptide, has been used in clinic as a modulator for immnuodeficiencies through intramuscular administration. The objectives of this study was to investigate the pharmacokinetics using normal rats and toxicity of nasal cilia as well as immunomodulating effects using immunosuppression rats after intranasal delivery of thymopentin with or without an absorption enhancer. The absorption extent of fluorescein isothiocyanate (FITC) labeled TP 5 via nasal delivery at a single dose is significantly improved by incorporating sodium deoxycholate, Brij 35 and chitosan, respectively. FITC-TP 5 can also be absorbed to such an extent ranging from 15 to 28% after intranasal administration of FITC-TP 5 alone, FITC-TP 5 with sodium caprylate, or with bacitracin, respectively. After seven consecutive days multiple dosing, TP 5 formulation with sodium deoxycholate or Brij 35 caused apparently injury to nasal cilia, indicating these two enhancers would not be appropriate for nasal delivery. Results from superoxide dismutase activity, maleic dialdehyde, T-lymphocyte subsets (CD3+, CD4+, CD8+ and CD4+/CD8+ ratio) analyses suggest that all the selected enhancers improve the modulating effects of TP 5 in the immunosuppression rats. On an overall evaluation, intranasal TP 5 alone, TP 5 with chitosan, or TP 5 with bacitracin formulation may be suitable for the future clinical application.

Absorption↗
PubMed2005

ReAS: Recovery of ancestral sequences for transposable elements from the unassembled reads of a whole genome shotgun.

We describe an algorithm, ReAS, to recover ancestral sequences for transposable elements (TEs) from the unassembled reads of a whole genome shotgun. The main assumptions are that these TEs must exist at high copy numbers across the genome and must not be so old that they are no longer recognizable in comparison to their ancestral sequences. Tested on the japonica rice genome, ReAS was able to reconstruct all of the high copy sequences in the Repbase repository of known TEs, and increase the effectiveness of RepeatMasker in identifying TEs from genome sequences.

Algorithms↗
PubMed2005

Poly I:C prevents T cell-mediated hepatitis via an NK-dependent mechanism.

BACKGROUND/AIMS: T cell immune responses play key roles in the pathogenesis of viral hepatitis, and innate immunity is known to be also activated during this process, however, the effects of innate immunity activation on T cell-mediated hepatitis remain obscure. Here we examined the effect of the activation of NK cells induced by toll-like receptor 3 (TLR3) ligand, polyinosinic-polycytidylic acid (poly I:C), on concanavalin A (Con A)-induced T cell-mediated liver injury. METHODS: Mice received nontoxic intraperitoneal poly I:C injection before Con A intravenous administration. The liver injury was examined by measuring serum transaminase and pathology, and the function of hepatic lymphocytes was detected by FACS analysis. RESULTS: Poly I:C pretreatment protected against T cell-mediated hepatitis, as evidenced by decreased mortality, hepatic necrosis, serum transaminase levels and inflammatory cytokines (IL-4, IFN-gamma). The protective effect of poly I:C was diminished in NK-depleted mice, which could be partially restored by adoptive transfer of NK cells. Administration of poly I:C caused NKT and T cell apoptosis via enhancing expression of Fas protein on these cells and expression of Fas ligand on NK cells. CONCLUSIONS: These findings suggest that activation of NK cells by poly I:C prevents Con A-induced T cell-hepatitis via downregulation of T/NKT cells and subsequent reduction of inflammatory cytokines.

Animals↗