Biomedical subjects

Jing Wang

Publications and source records attributed to Jing Wang.

At least 127 records · Page 7Linked to original sources

PubMed2006

Monitoring protein kinase A activities using expressed substrate in live cells.

Protein kinase A (PKA) activity is regulated by intracellular cyclic adenosine monophosphate. Conventional protein kinase assays after cell lysis are hence not suitable for analyzing PKA activities. In this chapter, we describe a new method for monitoring PKA activity in live cells. A triparti substrate for PKA (Myr-HA-beta2AR-C) is constructed that contains an N-terminal myristylation sequence followed by an antigenic hemagglutinin epitope tag and a substrate motif (the C-terminal tail of human beta2 adrenergic receptor). The PKA phosphorylation status of the substrate in frog oocytes is determined either by two-dimensional electrophoresis followed by HA epitope immunoblotting or by direct SDS-PAGE followed by immunoblotting using anti-P-beta2 adrenergic receptor antibodies specifically recognizing the PKA-phosphorylated C-terminus. We also describe the application of this strategy in mammalian somatic cells through DNA transfection. Myr-HA-beta2AR-C should be widely adaptable as an in vivo PKA activity indicator.

Animals↗

PubMed2006

Real-time three-dimensional color Doppler flow imaging: an improved technique for quantitative analysis of aortic regurgitation.

The recently introduced real-time three-dimensional color Doppler flow imaging (RT-3D CDFI) technique provides a quick and accurate calculation of regurgitant jet volume (RJV) and fraction. In order to evaluate RT-3D CDFI in the noninvasive assessment of aortic RJV and regurgitant jet fraction (RJF) in patients with isolated aortic regurgitation, real-time three-dimensional echocardiographic studies were performed on 23 patients with isolated aortic regurgitation to obtain LV end-diastolic volumes (LVEDV), end-systolic volumes (LVESV) and RJV, and then RJF could be calculated. The regurgitant volume (RV) and regurgitant fraction (RF) calculated by two-dimensional pulsed Doppler (2D-PD) method served as reference values. The results showed that aortic RJV measured by the RT-3D CDFI method showed a good correlation with the 2D-PD measurements (r = 0.93, Y = 0.89X + 3.9, SEE = 8.6 mL, P < 0.001); the mean (SD) difference between the two methods was--1.5 (9.8) mL. % RJF estimated by the RT-3D CDFI method was also correlated well with the values obtained by the 2D-PD method (r = 0.88, Y = 0.71X + 14.8, SEE = 6.4%, P < 0.001); the mean (SD) difference between the two methods was--1.2 (7.9) %. It was suggested that the newly developed RT-3D CDFI technique was feasible in the majority of patients. In patients with eccentric aortic regurgitation, this new modality provides additional information to that obtained from the two-dimensional examination, which overcomes the inherent limitations of two-dimensional echocardiography by depicting the full extent of the jet trajectory. In addition, the RT-3D CDFI method is quick and accurate in calculating RJV and RJF.

Adolescent↗

PubMed2006

Epidemiology of hepatitis B, C, D and G viruses and cytokine levels among intravenous drug users.

To investigate the features of various hepatitis virus infection in intravenous drug users (IVDU), we conducted an epidemiological survey of hepatitis viruses including hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis G virus (HGV) in IVDU. The correlation of TH lymphocyte cytokine and hepatitis virus infection was examined. A study population of 406 IVDU consisted of 383 males and 23 females. HBV-DNA and HCV-RNA were detected by fluorescence quantitative polymerase chain reaction. HBsAg, HBeAg, anti-HBc, anti-HCV, HDV-Ag and anti-HGV were assayed by ELISA. The levels of cytokines of TH1 and TH2 were measured by ELISA. The similar indices taken from 102 healthy persons served as controls. The infection rate of each virus among IVDU was 36.45 % for HBV, 69.7 % for HCV, 2.22 % for HDV, and 1.97 % for HGV, respectively. The co-infection rate of HBV and HCV was detected in 113 of 406 (27.83 %). In contrast, among controls, the infection rate was 17.65 % for HBV and 0 % for the other hepatitis viruses. The levels of PHA-induced cytokines (IFN-gamma and IL-4) and the level of serum IL-2 were obviously decreased in IVDU. On the other hand, the level of serum IL-4 was increased. The IFN-gamma level was continuously decreased when the IVDU was infected with HBV/HCV. In conclusion, HBV and HCV infection were common in this population of IVDU and they had led to a high incidence of impaired TH1 cytokine levels.

Adolescent↗

PubMed2006

Rural-to-urban migrants and the HIV epidemic in China.

China is the next probable frontier for the global HIV epidemic. Central to this anticipated growth of the epidemic is the nation's new and growing population of rural-to-urban migrants. Although there are an estimated 120 million migrants, little information is available about their social and cultural context of their lives in urban areas and their HIV-related perceptions and behaviors. On the basis of the in-depth individual interviews conducted among 90 rural-to-urban migrants in 2 major Chinese cities, Beijing and Nanjing, this qualitative study was designed to explore these issues with a particular focus on their relevance to sexual transmission of HIV. The findings suggest an urgent need for HIV/STI prevention programs that address the cultural, social, and economic constraints facing the migrant population in China.

Adult↗

PubMed2006

Ceramide induces apoptosis via a peroxisome proliferator-activated receptor gamma-dependent pathway.

Both of ceramide and PPARgamma ligand can trigger cancer cell apoptosis. We here show that C2-ceramide can modulate PPARgamma expression level and its transcriptional activity and results in apoptosis in HT29 cells. Administration of PPARgamma specific antagonist GW9662 partially prevents HT29 cells from apoptosis. Furthermore, MAP kinase pathway provided a potential modulation mechanism for PPARgamma pathway related with ceramide. Our results are the first to demonstrate that C2-ceramide induces apoptosis via a PPARgamma-dependent pathway.

Anilides↗

PubMed2006

Bioaugmentation of bromoamine acid degradation with Sphingomonas xenophaga QYY and DNA fingerprint analysis of augmented systems.

One high-effective bromoamine acid (1-amino-4-bromoanthraquinone-2-sulfonic acid, BAA) degrading strain was isolated previously with the ability to use BAA as sole source of carbon and nitrogen. It was identified as Sphingomonas xenophaga QYY by 16S rDNA sequence analysis and physio-biochemical tests. In this study, bioaugmentation of BAA degradation with suspended and immobilized cells of strain QYY was investigated. The optimal degradation conditions were as follows: temperature 30 degrees C, pH 6.0-7.0, 150 rev min(-1) and the immobilized cells maintained degradation activity to BAA after 60 days storage at 4 degrees C. The structure of BAA was evidently changed according to the analysis of total organic carbon removal of BAA (about 50%) and the UV-VIS spectra changes during the biodegradation. Bioaugmented systems exhibited stronger abilities degrading BAA than the non-bioaugmented control ones. And microbial community dynamics of augmented systems was revealed by amplified ribosomal DNA restriction analysis (ARDRA), a modern DNA fingerprint technique. The results indicated that the microbial community dynamics was substantially changed throughout the augmentation process. This study suggests that it is feasible and potentially useful to enhance BAA degradation using bioaugmentation with the immobilized cells of BAA-degrading bacterium.

Anthraquinones↗

PubMed2006

Study of biodegradable and self-expandable PLLA helical biliary stent in vivo and in vitro.

Biodegradable stents have advantages for the treatment of benign and malignant biliary stricture, especially eliminating the need for stent removal. In our present work, helical poly-l-lactic acids (PLLA) stent was fabricated and evaluated in vivo and in vitro. For in vivo study, bile duct injury canine models were made by transection of common bile ducts. Duct to duct anastomosis was done with helical PLLA biodegradable stents. Scanning electron microscopy (SEM) and histopathology were performed after three months. For In vitro study, sludge attachment assessment was performed. Polyethylene (PE) and PLLA membranes were immersed in human bile for two months. The samples were taken out and characterized by SEM. Self-expanding property of the helical stent was tested in 37 degrees Celsius water. The results demonstrate that the biodegradable stent had not only good biocompatibility, but also self-clearing effect to clear the attached sludge away. The self-expanding property facilitated stent implantation and also suggested possibility to be implanted endoscopically.

Absorbable Implants↗

PubMed2006

Genomic compositions and phylogenetic analysis of Shigella boydii subgroup.

Comparative Genomic Hybridization (CGH) microarray analysis was used to compare the genomic compositions of all eighteen Shigella boydii serotype representative strains. The results indicated the genomic "backbone" of this subgroup contained 2552 ORFs homologous to nonpathogenic E. coli K12. Compared with the genome of K12199 ORFs were found to be absent in all S. boydii serotype representatives, including mainly outer membrane protein genes and O-antigen biosynthesis genes. Yet the specific ORFs of S. boydii subgroup contained basically bacteriophage genes and the function unknown (FUN) genes. Some iron metabolism, transport and type II secretion system related genes were found in most representative strains. According to the CGH phylogenetic analysis, the eighteen S. boydii serotype representatives were divided into four groups, in which serotype C13 strain was remarkably distinguished from the other serotype strains. This grouping result corresponded to the distribution of some metabolism related genes. Furthermore, the analysis of genome backbone genes, specific genes, and the phylogenetic trees allowed us to discover the evolution laws of S. boydii and to find out important clues to pathogenesis research, vaccination and the therapeutic medicine development.

Gene Deletion↗

PubMed2006

Comparison of the virulence plasmid genomes of two strains of Shigella which lost the ability to bind Congo red.

We determined and analyzed the Shigella flexneri serotype 5 (pSF5) and S. dysenteriae serotype 1 (pSD1) virulence plasmid genomes. The total length of pSF5 is 136513 bp, including 165 open reading frames (ORFs). Of these ORFs, 133 were identified and 32 of those had no significant homology to proteins with known functions. The length of pSD1 is 182545 bp, including 224 ORFs, of which we identified 181. The remaining 43 ORFs were not significantly homologous to proteins with known functions. The insertion sequence (IS) elements are 53787 bp in pSF5, and 49616 bp in pSD1, which represents 39.4% and 27.1% of the genome, respectively. There are 22 IS element types in pSF5 and pSD1, among which we report ISEc8 and ISSbo6 for the first time in the Shigella virulence plasmid. Compared to pCP301, there are a large number of deleted genes and gene inversions in both pSF5 and pSD1. The ipa-mxi-spa locus in pSF5 is completely absent, and the genes related to the O-antigen biosynthesis are partially missing. In contrast, the above genes in pSD1 are integral, with the exception of virF. The whole genome analysis of the two plasmids shows that the loss of genes related to gene invasion or regulation also obliterates the ability of pPF5 and pSD1 to bind Congo red (Crb). Whether these genes determine the Crb function requires continued investigation.

Acyltransferases↗

PubMed2006

Real-time three-dimensional echocardiography in assessment of congenital double orifice mitral valve.

The application of real-time three-dimensional echocardiography (RT 3DE) in the diagnosis of double orifice mitral valve (DOMV) was explored. Five cases of DOMV were examined by using 2-dimensional echocardiography (2DE) and RT 3DE. The spatial morphology of malformed mitral valve and its change in hemodynamics were observed. DOMV associated with partial atrioventricular septal defect was found in 3 cases (in which 2 cases had cleft mitral valve) and isolated DOMV in 2 cases; and moderate to severe mitral regurgitation was detected in 3 cases, and mild mitral regurgitation in 1, and no regurgitation in 1 case; 1 case had complicated rhumatic heart disease. Three cases were preoperatively discovered by 2DE, while 2 missed (1 case was discovered postoperatively). Four cases were diagnosed by RT 3DE preoperatively, and 1 case was diagnosed postoperatively (not examined by RT 3DE preoperatively). It was suggested that RT 3DE is a reliable technique in the diagnosis of DOMV; it permitted comprehensive and noninvasive assessment of mitral valve and may supplement 2D TTE in the assessment of DOMV.

Abnormalities, Multiple↗

PubMed2006

Intravitreal triamcinolone acetonide concentration after subtenon injection.

PURPOSE: To determine concentration of intravitreal triamcinolone after subtenon injection. DESIGN: Prospective series of vitrectomy candidates and laboratory investigation. METHODS: Twenty eyes of 20 patients received subtenon injections of triamcinolone acetonide, 40 mg, before vitrectomy surgery. Exclusion criteria included previous history of vitrectomy, triamcinolone injection, and retinal detachment. Posterior subtenon injections were performed using the standard technique. Undiluted vitreous specimens were obtained at the time of vitrectomy, which was performed from one to 29 days after subtenon injection. Intravitreal triamcinolone concentration was determined by high-performance liquid chromatography. RESULTS: No complications were associated with subtenon injections. Intravitreal triamcinolone concentrations varied considerably, from zero in five eyes to a high of 4.94 microg/ml. CONCLUSIONS: Intravitreal triamcinolone concentrations vary considerably after subtenon injection. The findings indicate that subtenon injection can be a method for administering intravitreal triamcinolone acetonide that is comparable, in some cases, to the levels achieved after intravitreal injection.

Chromatography, High Pressure Liquid↗

PubMed2006

Comprehensive proteomic analysis of Shigella flexneri 2a membrane proteins.

Shigella flexneri is the causative agent of most shigellosis cases in developing countries. We used different proteolytic enzymes to selectively shave the protruding proteins on the surface of purified bacterial membrane sheets or vesicles, and recovered peptides were subsequently identified using 2-D LC-MS/MS. As a result, a total of 666 proteins were unambiguously assigned, including 159 integral membrane proteins, 35 outer membrane proteins and 114 proteins previously annotated as hypothetical. The former had an average grand average hydrophobicity score of 0.362 and were predicted to separate within a pH range of 4.1-10.6 with molecular mass 8-148 kDa, which represents the largest validated set of integral membrane proteins in this organism to date. A functional classification revealed that a large proportion of the identified proteins were involved in cell envelope biogenesis and energy production and conversion. For the first time, this work provides a global view of the S. flexneri 2a membrane subproteome.

Bacterial Outer Membrane Proteins↗

PubMed2006

Epitopes in the linker subdomain region of envoplakin recognized by autoantibodies in paraneoplastic pemphigus patients.

Sera from paraneoplastic pemphigus (PNP) immunoprecipitate multiple antigens from human epidermal protein extract. In this study, we further characterized the autoantibodies in 12 PNP sera. Immunoblotting using recombinant linker subdomains of envoplakin, periplakin, desmoplakin, and bullous pemphigoid antigen I found that 11 of the 12 sera recognized linker subdomains of envoplakin and periplakin. We then synthesized 12 peptides covering the linker subdomain of envoplakin for ELISA. One of the peptides, peptide no. 8, was recognized by nine out of the 12 sera with a higher affinity. A method of ligand-receptor binding assay was designed and performed using this peptide labeled with fluorescence as the ligand. Peptide no. 8 bound to CD20+ cells in Castleman's tumors from the patients whose sera were positive to this peptide by ELISA. Our data suggest that the linker subdomain of plakin proteins may be one of the major areas recognized by PNP autoantibodies, and epitopes in the linker subdomain of envoplakin recognized by PNP autoantibodies with a high affinity are dispersed in several areas and are variable among PNP patients. We also demonstrate that B-lymphocyte clones specifically reacting to epidermal proteins exist in Castleman's tumors from PNP.

Adolescent↗

PubMed2006

A model study of interactions between TcAChE peripheral site segment Tyr70Val71 and loop 1 of Fasciculin 2.

The continuous chain of residues (Thr7 to Ala12) of Loop1 of Fas2 (F1) and its interaction with the peripheral binding sites (Tyr70-Val71) of AChE (P1) has been studied. Our results suggest that the flexibility of Loop1 might be caused by either the partially protonated guanidine group of Arg11 under experimental conditions or by the interaction with the negatively charged center of substrates. The binding energy of F1-P1 is predicted to be -16.6 kcal/mol at the B3LYP/6-311G(d,p) level, which is assumed to originate from one isolated O7...HN10 H-bond, one possible O10...HC71 unconventional O...HC type H-bonding, and the improved pi-bonding cooperativity around the peptide group of the AChE segment Tyr70-Val71. The classical Kitaura-Morokuma energy decomposition analysis, the NPA charge analysis, and the AIM analysis consistently reveal that the peptide group in segment P1 is more polarizable, which might play the key role in the interactions between F1 and P1. The PCM solvent effect corrected results reveal decrease of the interaction energy of the considered model. The importance of Thr8 of Fas2 in the P-site binding of AChE is also concluded. Site-directed mutations on either the Fas2 residue of Thr8 or the AChE residue of Tyr70 are expected to alter the binding behavior of the Loop1 of Fas2 with AChE.

Acetylcholinesterase↗

PubMed2006

Investigation of GM-CSF immune accessory effects in tumor-bearing mice by direct gene immunization.

To assess GM-CSF immune accessory effects in tumor-bearing mice, an animal tumor model was established by inoculating SP2/0 myeloma cells s.c. into the flank of Balb/c mice and 14 days later, injecting either 400 mug recombinant pcDNA3.1/mGM-CSF or a blank plasmid s.c. or i.m. into the tumor four times. The tumor weight, the activities of CTL and NK, the serum levels of IFN-gamma, IL-2 and lymphocytes infiltrating in tumor tissue were analysed 8 weeks later with MTT, ELISA and pathological section methods. The results showed that the tumor lump was reduced in mice injected s.c. (0.880 +/- 0.405 g) or i.m. (0.378 +/- 0.411 g) with pcDNA3.1/mGM-CSF compared with control mice injected s.c. (1.548 +/- 0.221g, P < 0.01)or i.m. (1.554 +/- 0.249g, P < 0.001) with a blank vector. Lymphocyte infiltration in tumor tissues was very apparent in mice injected i.m. with pcDNA3.1/mGM-CSF. In contrast, there was no lymphocyte infiltration in tumor tissues of control mice. In addition, the serum concentrations of IFN-gamma, IL-2 and the activities of CTL and NK cells were significantly increased in mice injected with pcDNA3.1/mGM-CSF compared with a control mice (P < 0.01). In conclusion, direct gene immunization of recombinant pcDNA3.1/mGM-CSF is a feasible strategy for tumor therapy.

Animals↗

PubMed2006

Correlates of syphilis seroreactivity among pregnant women: the HIVNET 024 Trial in Malawi, Tanzania, and Zambia.

OBJECTIVES: The objectives of this cross-sectional study were to determine correlates of syphilis seroprevalence among HIV-infected and -uninfected antenatal attendees in an African multisite clinical trial, and to improve strategies for maternal syphilis prevention. RESULTS: A total of 2,270 (86%) women were HIV-infected and 366 (14%) were HIV-uninfected. One hundred seventy-five (6.6%) were syphilis-seropositive (7.3% among HIV-infected and 2.6% HIV-uninfected women). Statistically significant correlates included geographic site (odds ratio [OR] = 4.5, Blantyre; OR = 3.2, Lilongwe; OR = 9.0, Lusaka vs. Dar es Salaam referent); HIV infection (OR = 3.3); age 20 to 24 years (OR = 2.5); being divorced, widowed, or separated (OR = 2.9); genital ulcer treatment in the last year (OR = 2.9); history of stillbirth (OR = 2.8, one stillbirth; OR = 4.3, 2-5 stillbirths); and history of preterm delivery (OR = 2.7, one preterm delivery). CONCLUSION: Many women without identified risk factors were syphilis-seropositive. Younger HIV-infected women were at highest risk. Universal integrated antenatal HIV and syphilis screening and treatment is essential in sub-Saharan African settings.

Adolescent↗

PubMed2006

Noise Reduction for Low-Dose Single-Slice Helical CT Sinograms.

Helical computed tomography (HCT) has several advantages over conventional step-and-shoot CT for imaging a relatively large object, especially for dynamic studies. However, HCT may increase X-ray exposure significantly. This work aims to reduce the radiation by lowering X-ray tube current (mA) and filtering low-mA (or dose) sinogram noise of HCT. The noise reduction method is based on three observations on HCT: (1) the axial sampling of HCT projections is nearly continuous as detection system rotates; (2) the noise distribution in sinogram space is nearly a Gaussian after system calibration (including logarithmic transform); and (3) the relationship between the calibrated data mean and variance can be expressed as an exponential functional across the field-of-view. Based on the second and third observations, a penalized weighted least-squares (PWLS) solution is an optimal choice, where the weight is given by the mean-variance relationship. The first observation encourages the use of Karhunen-Loève (KL) transform along the axial direction because of the associated correlation. In the KL domain, the eigenvalue of each principal component and the derived data variance provide the signal-to-noise ratio (SNR) information, resulting in a SNR-adaptive noise reduction. The KL-PWLS noise-reduction method was implemented analytically for efficient restoration of large volume HCT sinograms. Simulation studies showed a noticeable improvement, in terms of image quality and defect detectability, of the proposed noise-reduction method over the Ordered-Subsets Expectation-Maximization reconstruction and the conventional low-pass noise filtering with optimal cutoff frequency and/or other filter parameters.

Journal Article↗

PubMed2006

Relief texture from specularities.

In vision and graphics, advanced object models require not only 3D shape, but also surface detail. While several scanning devices exist to capture the global shape of an object, few methods concentrate on capturing the fine-scale detail. Fine-scale surface geometry (relief texture), such as surface markings, roughness, and imprints, is essential in highly realistic rendering and accurate prediction. We present a novel approach for measuring the relief texture of specular or partially specular surfaces using a specialized imaging device with a concave parabolic mirror to view multiple angles in a single image. Laser scanning typically fails for specular surfaces because of light scattering, but our method is explicitly designed for specular surfaces. Also, the spatial resolution of the measured geometry is significantly higher than standard methods, so very small surface details are captured. Furthermore, spatially varying reflectance is measured simultaneously, i.e., both texture color and texture shape are retrieved.

Algorithms↗