Biomedical subjects

Jing Tang

Publications and source records attributed to Jing Tang.

At least 19 recordsLinked to original sources

PubMed2026

Genomic and transcriptomic features of HBV integration in treatment-naïve, HBeAg-positive children with chronic HBV infection.

BACKGROUND: Hepatitis B virus (HBV) integration represents a major obstacle to curing HBV; however, the landscape of HBV integration and local immune response to transcriptionally active viral integration in children with chronic HBV infection remain unclear. Herein, we aimed to elucidate this landscape in this population. METHODS: Genomic analyses using a probe-based capture strategy were performed on 18 children and 28 adults with chronic HBV infection. Spatial transcriptomics (ST) was performed on 12 children from our cohort and 3 adults from a public database. FINDINGS: All patients were hepatitis B e antigen (HBeAg)-positive and treatment-naïve. Genomically, children exhibited significantly lower clonal expansion level of HBV-integrated hepatocytes than adults, despite comparable unique breakpoint counts. After adjusting for confounding variables, age was identified as an independent risk factor for total frequency of unique integration breakpoints (b = 3.22, P = 0.005). Spatially, ST revealed that spots with transcriptionally active viral integration exhibited a sparse distribution and accounted for a low proportion of all spots in children. Notably, at these spots, children showed reduced adaptive immune cells (e.g., CD8+ T cells) but increased innate components (myeloid cells, Kupffer cells, activated dendritic cells) and APC co-stimulation, whereas adults exhibited a uniform reduction of immune cell populations. INTERPRETATION: Compared with adults, children exhibit lower clonal expansion of HBV-integrated hepatocytes and distinct immune profiles in response to transcriptionally active viral integration, offering new insights into their differing clinical course. FUNDING: Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education).

Humans↗

PubMed2006

Bayesian analysis of population structure based on linked molecular information.

The Bayesian model-based approach to inferring hidden genetic population structures using multilocus molecular markers has become a popular tool within certain branches of biology. In particular, it has been shown that heterogeneous data arising from genetically dissimilar latent groups of individuals can be effectively modelled using an unsupervised classification formulation. However, most currently employed models ignore potential linkage within the employed molecular information, and can therefore lead to biased inferences under certain circumstances. Utilizing the general theory of graphical models, we develop a framework that accounts for dependences both within linked molecular marker loci and DNA sequence data. Due to a high level of sequence conservation among eukaryotic species, the latter aspect is particularly relevant for analyzing rapidly evolving microbial species. The advantages of incorporating the dependence due to linkage in the classification models are illustrated by analyses of both simulated data and real samples of Bacillus cereus.

Bacillus cereus↗

PubMed2006

A comparative study on electrochemical micromachining of n-GaAs and p-Si by using confined etchant layer technique.

The confined etchant layer technique has been applied to achieve effective three-dimensional (3D) micromachining on n-GaAs and p-Si. This technique operates via an indirect electrochemical process and is a maskless, low-cost technique for microfabrication of arbitrary 3D structures in a single step. Br(2) was electrogenerated at the mold surface and used as an efficient etchant for n-GaAs and p-Si; l-cystine was used as a scavenger, for both substrates. The resolution of the fabricated microstructure depended strongly on the composition of the electrolyte, and especially on the concentration ratio of l-cystine to Br(-). A well-defined, polished Pt microcylindrical electrode was employed to examine the deviation of the size of the etched spots from the real diameter of the microelectrode. The thickness of the confined etchant layer can be estimated, and thus the composition of the electrolyte can be optimized for better etching precision. The etched patterns were approximately negative copies of the mold, and the precision of duplication could reach the micrometer level for p-Si and the submicrometer level for n-GaAs. Although the same etchant (Br(2)) and scavenger (l-cystine) were used in the etching solutions for GaAs and Si, the etching process, or mechanism, is completely different in the two cases. Compared with the fast etching process on GaAs in an etching solution with a concentration ratio of 3:1 of l-cystine to Br(-), the concentration ratio needs to be 50:1 for etching of Si. For the micromachining of Si, the addition of a cationic surfactant (cetyltrimethylammonium chloride, CTACl) is necessary to reduce the surface tension of the substrate and hence reduce the influence of evolution of the byproduct H(2). The function of the surfactant CTACl in comparison with an anionic surfactant (sodium dodecyl sulfate) was studied in contact-angle experiments and micromachining experiments and then is discussed in detail.

Journal Article↗

PubMed2006

[High mobility group box-1 protein activates endothelial cells to produce cytokines and has synergistic effect with lipopolysaccharide in inducing interleukin-6 release].

OBJECTIVE: To observe the effects of high mobility group box 1 (HMGB1) protein on the release of cytokines of human umbilic vein endothelial cells (HUVECs) and the expression of interleukin-6 (IL-6) induced by lipopolysaccharide (LPS). METHODS: HUVECs were cultured and then divided into the following groups. (1) Recombinant HMGB1 protein of the terminal concentration of 15 ng/ml was added into the culture fluid of HUVECs, 24 hours later the supernatant was collected to detect the levels of granulocyte/macrophage colony stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), and interleukin-10, IL-12, IL-1beta, IL-2, IL-4, IL-6, and IL-8, by using LiquiChip system. (2) HMGB1 protein of the terminal concentrations of 3, 15, or 75 ng/ml was added into the culture fluid of the HUVECs, 24 hours later the supernatants were collected to detect the level of IL-6. (3) HMGB1 protein of the terminal concentration of 15 ng/ml was added into the culture fluid of HUVECs, 1, 3, 6, 12, and 24 hours after the stimulation the supernatant was collected to detect the level of IL-6. (4) The culture fluid of HUVECs was added with HMGB1 protein of the terminal concentration of 15 ng/ml and/or LPS of the concentration of 10 ng/ml, 24 hours later the supernatant was collected to detect the level of IL-6. Culture fluid not added with HMGB1 protein was used as control in any kind of test. RESULTS: (1) The levels of GM-CSF, IFN-gamma, IL-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1) secreted by the HMGB1 stimulated HUVECs were 5, 7, 4.2, 27.8, 12.8, and 5.4 times that of those control group (all P < 0.01) (2) The levels of IL-6 secreted by the HUVECs stimulated with HMGB1 protein of the concentrations of 3, 15 and 75 ng/ml respectively were 155 pg/ml +/- 33 pg/ml, 901 pg/ml +/- 184 pg/ml, and 1508 pg/ml +/- 379 pg/ml respectively, all significantly higher than that of the control group (32 pg/ml +/- 21 pg/ml, all P < 0.01). (3) Since 3 h after the stimulation of HMGB1 protein the level of IL-6 began to increase gradually. 6, 12, and 24 hours after the stimulation the levels of IL-6 secreted by the HUVEC were 75 pg/ml +/- 22 pg/ml, 453 pg/ml +/- 78 pg/ml, and 901 pg/ml +/- 184 pg/ml respectively, all significantly higher than that of the control group (32 pg/ml +/- 21 pg/ml, all P < 0.01). (4) When the HUVECs were stimulated individually by LPS (10 ng/ml) or HMGB1 (15 ng/ml), the levels of IL-6 increased to 289 pg/ml +/- 42 pg/ml and 901 pg/ml +/- 183.6 pg/ml respectively (both P < 0.01); when the HUVECs were costimulated by LPS and HMGB1, the level of IL-6 increased to 2360 pg/ml +/- 299 pg/ml, which showing that there was a synergistic effect between HMGB and LPS (F = 69.405, P < 0.001). CONCLUSION: HMGB1 activates HUVECs to produce multiple inflammatory cytokines and induces HUVEC to secret IL-6 in a dose- and time-dependent manner. HMGB1 can also act synergistically with LPS in inducing IL-6 release, which may play an important role in the development of sepsis.

Cell Line↗

PubMed2006

Responsive periodic mesoporous polydiacetylene/silica nanocomposites.

Responsive PMO materials have been synthesized through co-assembly of bridged diacetylenic silsesquioxane and surfactant. The spatially defined polydiacetylenic component, mesoporous network, and the covalent proximity of polydiacetylene to silica endow the PMO with mechanical robustness, reversible chromatic responses, improved thermal stability, and faster responses to chemical stimuli. This research also provides an efficient molecular design and assembly paradigm to fabricate a family of conjugated optoelectronic materials, creating novel platforms for sensors, actuators, and other device applications.

Nanocomposites↗

PubMed2006

Crystal splitting in the growth of Bi2S3.

Bi2S3 nanostructures with a sheaflike morphology are obtained via reaction of bismuth acetate-oleic acid complex with elemental sulfur in 1-octadecence. These structures may form by the splitting crystal growth mechanism, which is known to account for the morphology some mineral crystals assume in nature. By control of the synthetic parameters, different shapes are obtained, analogous to those which have been observed to occur by crystal splitting in minerals. These new and complex Bi2S3 nanostructures are characterized by transmission and scanning electron microscopy, and electron and X-ray diffraction.

Journal Article↗

PubMed2006

[Application of two-color infrared fluorescence for detection of protein phosphorylation].

OBJECTIVE: To assess the value of two-color infrared fluorescence imaging system in detecting protein phosphorylation in comparison with chemiluminescent detection. METHOD: The lung tissue homogenate of mice treated with lipopolysaccharide (LPS) for different time lengths were prepared to separate the proteins by SDS-polyacrylamide gel electrophoresis followed by transfer of the proteins onto PVDF membranes. The membranes were incubated with the antibodies against total p42/44 MAPK/phospho-p42/44 MAPK, and then with goat anti-mouse or anti-rabbit secondary antibodies conjugated to Alexa Fluor 680, IRDye 800 or horseradish peroxidase. The blotted proteins were detected and quantified using Odyssey infrared imaging system or chemiluminescent detection. RESULTS: LPS treatment rapidly induced p42/44 MAPK phosphorylation, which reached the peak level 1 h after the treatment and resumed the baseline level at 12 h. Consistent results were obtained by the two detection methods, but two-color infrared fluorescence imaging system showed better sensitivity in detecting the target protein, and was easy to manipulate with good efficiency and capable of analyzing two proteins simultaneously. CONCLUSION: Two-color infrared fluorescence system is a powerful system for detecting phosphorylation of proteins.

Animals↗

PubMed2006

[Characteristics and operation of enhanced continuous bio-hydrogen production reactor using support carrier].

A kind of granular activated carbon, whose granular size is no more than 2mm and specific gravity is 1.54g/cm3, was used as the support carrier to allow retention of activated sludge within a continuous stirred-tank reactor (CSTR) using molasses wastewater as substrate for bio-hydrogen production. Continuous operation characteristics and operational controlling strategy of the enhanced continuous bio-hydrogen production system were investigated. It was indicated that, support carriers could expand the activity scope of hydrogen production bacteria, make the system fairly stable in response to organic load impact and low pH value (pH <3.8), and maintain high biomass concentration in the reactor at low HRT. The reactor with ethanol-type fermentation achieved an optimal hydrogen production rate of 0.37L/(g x d), while the pH value ranged from 3.8 to 4.4, and the hydrogen content was approximately 40% approximately 57% of biogas. It is effective to inhibit the methanogens by reducing the pH value of the bio-hydrogen production system, consequently accelerate the start-up of the reactor.

Bacteria, Anaerobic↗

PubMed2006

[Analysis of Toll-like receptor 4 and myeloid differentiation protein-2 interaction with fluorescence resonance energy transfer].

OBJECTIVE: To study the interaction between Toll-like receptor (TLR) 4 and myeloid differentiation protein-2 (MD-2) in living cells using fluorescence resonance energy transfer (FRET) technology. METHODS: The coding sequences of TLR4 and MD-2 (without the signal peptide sequence) were amplified by PCR and cloned into enhanced cyan fluorescence protein (CFP) and enhanced yellow fluorescence protein (YFP) expression vectors carrying TLR4 signal peptides (pECFP-C1-SP and pEYFP-C1-SP). HEK293 cells were transfected respectively or together with the reconstructed plasmids verified by enzyme digestion and sequence analysis, and the expression and sublocalization of these fluorescence proteins in the cells were observed using fluorescence microscope. FRET in the cells coexpressing CFP-TLR4 and YFP-MD-2 was detected using routine and acceptor photobleaching method. RESULTS: The reconstructed plasmids were expressed in HEK293 cells. The cyan or yellow fluorescence was located in the cytoplasm, mainly around the nucleus in the cells transfected with pECFP/TLR4 or pEYFP/MD-2, and both the cyan and yellow fluorescence located mainly in the membrane and occasional in the cytoplasm of cells cotransfected with pECFP/TLR4 and pEYFP/MD-2. Routine or acceptor photobleaching detected FRET phenomena in cells coexpressing CFP-TLR4 and YFP-MD-2, suggesting direct interaction between TLR4 and MD-2. CONCLUSION: This study provides direct evidence of the interaction between TLR4 and MD-2 in living cells.

Cell Line↗

PubMed2006

[Involvement of nitric oxide in regulation of salt stress-induced ABA accumulation in maize seedling].

Possible regulation of salt stress-induced ABA accumulation by nitric oxide (NO) in maize seedling was investigated. Both NO and ABA contents of maize leaves and root tips were increased in response to salt stress (Fig.1,2). Similar to the effects of salt stress, ABA contents of maize leaves and root tips were increased after the treatment of maize leaves with sodium nitroprusside (SNP, a nitric oxide donor) alone (Fig.3). Compared to the salt stress-induced ABA accumulation, this SNP-induced ABA increase was much faster, suggesting that NO may be an intermediate signal from salt stress to ABA accumulation. When NO production inhibitors L-NAME and NaN(3) treatments were applied, salt stress-induced ABA accumulation was lowered (Fig.4). Treatment with NO scavenger cPTIO also inhibited the salt stress-induced ABA increase (Fig.5). From these results it is deduced that NO is involved in regulation of ABA accumulation under salt stress.

Abscisic Acid↗

PubMed2006

[The effect of tetramethylpyrazine on the pharmacokinetics of intragastrically administered cyclosporine A in rats].

AIM: To investigate the possible effect of tetramethylpyrazine (TMP), an active ingredient of a commonly used Chinese herb, on the pharmacokinetics of cyclosporine A (CsA) by intragastric administration in rats. METHODS: Forty male Sprague-Dawley rats were equally divided into four groups by randomized block design according to weight. On the first day, after each fasting rat was intragastrically administered CsA (10 mg x kg(-1)), blood samples (0.2 - 0.25 mL) were collected from the tail vein at 0, 1, 2, 3, 4, 6, 8, 12, 24, 36 and 48 h. From day 4 to day 8, each group began to undergo different pretreatments with intragastric administration of water, verapamil (Ver), low and high dose TMP, separately. On day 9, each group intragastrically co-administered CsA (10 mg x kg(-1)) and different pretreatment compounds mentioned above, then blood samples were collected according to the schedule of the first day. The whole blood concentration of CsA was determined by HPLC. Main pharmacokinetic parameters were calculated and compared by statistic analysis. RESULTS: In the group of water pretreated and co-administrated with CsA, no significantly different pharmacokinetic parameters of CsA were found. After Ver pretreatment and co-administration with CsA, AUC(0-48 h) and C(max) were increased significantly (P < 0.01 and P < 0.05); T(1/2) beta and CL were markedly prolonged and decreased (P < 0.05); T(max) and V were not apparently influenced. After low dose TMP pretreatment and co-administration with CsA, there was no significant difference in the pharmacokinetic parameters of CsA, in spite of the increasing trends of AUC(0-48 h) and C(max). After high dose TMP pretreatment and co-administration with CsA, AUC(0-48 h) and C(max) of CsA were increased significantly (P < 0.01), but there was no significant change in other parameters. CONCLUSION: It was indicated that the high dose of TMP could apparently increase the intragastric absorption extent of CsA, while almost had no effect on its elimination process.

Administration, Oral↗

PubMed2005

A templating route to nanoporous chitosan materials.

Nanoporous chitosan materials in both membrane and bulk form with pore diameter ranges of 10-50 nm were prepared by a novel emulsion-mediated templating method. Considering the biocompatibility and versatility of chitosan, the nanoporous chitosan material is expected to have a wide variety of applications in the biotechnological and biomaterials areas.

Carbohydrate Conformation↗

PubMed2005

Polydiacetylene/silica nanocomposites with tunable mesostructure and thermochromatism from diacetylenic assembling molecules.

Conjugated polydiacetylene (PDA)/silica nanocomposites with tunable mesostructures and reversible thermochromatism were synthesized through self-directed assembly of diacetylenic silanes. In contrast to the previous studies, where the PDA side chains interacted weakly through noncovalent interactions, the side chains in the present nanocomposites are covalently connected to the inorganic silica frameworks, providing control over the molecular alignment, stability, and electronic properties. Furthermore, tuning the molecular architecture (e.g., the shape and side-chain length) allows control over the mesostructure (e.g., cubic and lamellar) and chromatic response of the nanocomposites (from irreversible to partially reversible and then to completely reversible). As a result of the covalent interactions, the nanocomposites also demonstrate higher reversible chromatic transition temperatures. This work not only provides responsive robust chromatic materials toward practically reusable PDA sensors but also is of great fundamental value for the design of supramolecular assembly and the understanding of the chromatic mechanism of PDA.

Acetylene↗

PubMed2005

An organometallic synthesis of TiO2 nanoparticles.

We report the synthesis of TiO2 nanoparticles that uses the low-temperature reaction of low-valent organometallic precursors. Bis(cyclooctatetraene)titanium reacts with dimethyl sulfoxide in organic solution at temperatures as low as room temperature to produce TiO2. In the absence of any supporting ligand, the reaction gives precipitation of amorphous TiO2 powder; however, in the presence of basic ligands such as tributylphosphine, tributylphosphine oxide and trioctylphosphine oxide, the precipitation is arrested, and chemically distinct, isolated, internally crystalline TiO2 nanoparticles are formed.

Crystallization↗

PubMed2005

Templated synthesis, characterization, and sensing application of macroscopic platinum nanowire network electrodes.

Novel platinum nanowire network electrodes have been fabricated through electrodeposition using mesoporous silica thin films as templates. These electrodes were characterized by X-ray diffraction, transmission electron microscope, and scanning electron microscope. The electrochemical properties of the electrodes, such as electrochemical active area and methanol oxidation, have also been studied. Compared with conventional polycrystalline Pt electrodes, these novel nanowire network electrodes possess high electrochemical active areas and demonstrate higher current densities and a lower onset potential for methanol electro-oxidation. Enzymatic Pt nanowire-network-based sensors show higher sensitivity for glucose detection than that using conventional polycrystalline Pt electrode. Such macroscopic nanowire network electrodes provide ideal platforms for sensing and other device applications.

Aspergillus niger↗

PubMed2005

[Mitochondrial DNA 3243, 3316 point mutations and type 2 diabetes mellitus].

OBJECTIVE: To investigate the prevalence of mitochondrial DNA (mtDNA) mutation at position 3243(A/G) and 3316(G/A) in Chinese patients with type 2 diabetes mellitus. METHODS: Two hundred and twenty-five unrelated Chinese patients with type 2 diabetes and 195 nondiabetic control individuals without family history of diabetes in Yunnan were examined. The presence of mt 3243 and 3316 mutations was determined by polymerase chain reaction amplification and restriction fragment length polymorphism (PCR/RFLP). Finally, mutant mtDNA was confirmed by DNA sequencing. RESULTS: The mitochondrial DNA mutation at position 3316 was found in 5 of 225 (2.22%) patients with type 2 diabetes, and this mutation was found in 2 of 195 (1.03%) control individuals. There was no significant difference in respect to the frequency of the mutation between patients and controls. The mitochondrial DNA mutation at position 3243 was not found in any of the patients and controls. CONCLUSION: The results suggest that the prevalence of the mitochondrial tRNA (Leu(UUR))gene at position 3243(A/G) mutation is so low that it may not be a major cause of type 2 diabetes mellitus in patients of Yunnan, China, and the mitochondrial ND1 gene at position 3316(G/A) mutation may be a polymorphism unrelated to diabetes in Chinese. The role of other genetic, environmental and intrauterine factors needs further investigation.

Adult↗

PubMed2005

[Start-up and continuous operation of bio-hydrogen production reactor at pH 5].

A continuous stirred-tank reactor(CSTR)for bio-hydrogen production using molasses wastewater as substrate was investigated. Emphasis was placed on assessing the start-up and continuous operation characteristics when keeping pH value constant. It was found that at pH of 5, biomass of 6g/L, organic loading rate (OLR) of 7.0kg/(m3 x d) and a hydraulic retention time (HRT) of 6h, an equilibrial hydrogen-producing microbial community could be established within 30 days. Following that, oxidation redox potential (ORP) were kept within the ranges - 460mV - -480mV. Typical mixed acid type fermentation was exhibited in the reactor. Little difference was observed in the distribution of liquid end products. The liquid end products proportion of the total amount was 36% of acetic acid, 33% of ethanol, 18% of butyric acid, 13% of propionic acid and valeric acid, respectively. Hydrogen content in the biogas was about 30% - 35% . Maximal hydrogen production rate was 1.3m3/(m3 x d). The acid-producing fermentative bacteria were in the same preponderant status when the reactor showed mixed acid type fermentation. They are mostly cocci and bacilli.

Bacteria, Anaerobic↗

PubMed2005

[Construction of eukaryotic expression vector for HPC2 and its expression in HEK293 cells].

OBJECTIVE: To construct the eukaryotic expression vector for HPC2 for expression in HEK293 cells. METHODS: HPC2 from pcDNA3/HPC2 were inserted into the flag-tagged vector pcDNA3-flag by subcloning method. The recombinant plasmid pcDNA3-flag/HPC2 was then transfected into HEK293 cells using a routine lipofectamine method. The cell lysate was used for Western blotting to examine the expression of the target protein. RESULTS AND CONCLUSION: Double restriction enzyme digestion and DNA sequencing indicated successful construction of the eukaryotic expression vector for HPC2 and the fusion protein was highly expressed in HEK293 cells, which provides an important basis for functional study of HPC2.

Cell Line↗