Biomedical subjects

Juan Wang

Publications and source records attributed to Juan Wang.

At least 37 records · Page 2Linked to original sources

PubMed2006

Yeast AMID homologue Ndi1p displays respiration-restricted apoptotic activity and is involved in chronological aging.

Apoptosis-inducing factor (AIF) and AIF-homologous mitochondrion-associated inducer of death (AMID) are both mitochondrial flavoproteins that trigger caspase-independent apoptosis. Phylogenetic analysis suggests that these two proteins evolutionarily diverge back from their common prokaryote ancestor. Compared with AIF, the proapoptotic nature of AMID and its mode of action are much less clarified. Here, we show that overexpression of yeast AMID homologue internal NADH dehydrogenase (NDI1), but not external NADH dehydrogenase (NDE1), can cause apoptosis-like cell death, and this effect can be repressed by increased respiration on glucose-limited media. This result indicates that the regulatory network of energy metabolism, in particular the cross-talk between mitochondria and the rest of the cell, is involved in Ndi1p-induced yeast cell apoptosis. The apoptotic effect of NDI1 overexpression is associated with increased production of reactive oxygen species (ROS) in mitochondria. In addition, NDI1 overexpression in sod2 background causes cell lethality in both fermentable and semifermentable media. Interruption of certain components in the electron transport chain can suppress the growth inhibition from Ndi1p overexpression. We finally show that disruption of NDI1 or NDE1 decreases ROS production and elongates the chronological life span of yeast, accompanied by the loss of survival fitness. Implication of these findings for Ndi1p-induced apoptosis is discussed.

Apoptosis↗

PubMed2006

HIV-1 Tat and opiate-induced changes in astrocytes promote chemotaxis of microglia through the expression of MCP-1 and alternative chemokines.

Opiates exacerbate human immunodeficiency virus type 1 (HIV-1) Tat(1-72)-induced release of key proinflammatory cytokines by astrocytes, which may accelerate HIV neuropathogenesis in opiate abusers. The release of monocyte chemoattractant protein-1 (MCP-1, also known as CCL2), in particular, is potentiated by opiate-HIV Tat interactions in vitro. Although MCP-1 draws monocytes/macrophages to sites of CNS infection, and activated monocytes/microglia release factors that can damage bystander neurons, the role of MCP-1 in neuro-acquired immunodeficiency syndrome (neuroAIDS) progression in opiate abusers, or nonabusers, is uncertain. Using a chemotaxis assay, N9 microglial cell migration was found to be significantly greater in conditioned medium from mouse striatal astrocytes exposed to morphine and/or Tat(1-72) than in vehicle-, mu-opioid receptor (MOR) antagonist-, or inactive, mutant Tat(delta31-61)-treated controls. Conditioned medium from astrocytes treated with morphine and Tat caused the greatest increase in motility. The response was attenuated using conditioned medium immunoneutralized with MCP-1 antibodies, or medium from MCP-1(-/-) astrocytes. In the presence of morphine (time-release, subcutaneous implant), intrastriatal Tat increased the proportion of neural cells that were astroglia and F4/80+ macrophages at 7 days post-injection. This was not seen after treatment with Tat alone, or with morphine plus inactive Tat(delta31-61) or naltrexone. Glia displayed increased MOR and MCP-1 immunoreactivity after morphine and/or Tat exposure. The findings indicate that MCP-1 underlies most of the response of microglia, suggesting that one way in which opiates exacerbate neuroAIDS is by increasing astroglial-derived proinflammatory chemokines at focal sites of CNS infection and promoting macrophage entry and local microglial activation. Importantly, increased glial expression of MOR can trigger an opiate-driven amplification/positive feedback of MCP-1 production and inflammation.

Animals↗

PubMed2006

Application of multislice spiral CT for guidance of insertion of thoracic spine pedicle screws: an in vitro study.

To investigate the value of the guidance of three dimensional (3-D) reconstruction of multi-slice spiral CT (MSCT) for the placement of pedicle screws, the 3-D anatomical data of the thoracic pedicles were measured by MSCT in two embalmed human cadaveric thoracic pedicles spines (T1-T10) to guide the insertion of pedicle screws. After pulling the screws out, the pathways were filled with contrast media. The PW, PH, TSA and SSA of developed pathways were measured on the CT images and they were also measured on the real objects by caliper and goniometer. Analysis of variance demonstrated that the difference between the CT scans and real objects had no statistical significance (P > 0.05). Moreover, the difference between pedicle axis and developed pathway also had no statistical significance (P > 0.05). The data obtained from 3-D reconstruction of MSCT demonstrated that individualized standards, are not only accurate but also helpful for the successful placement of pedicle screws.

Bone Screws↗

PubMed2006

A high throughput targeted gene disruption method for Alternaria brassicicola functional genomics using linear minimal element (LME) constructs.

Alternaria brassicicola causes black spot disease of cultivated Brassicas and has been used consistently as a necrotrophic fungal pathogen for studies with Arabidopsis. In A. brassicicola, mutant generation has been the most rate-limiting step for the functional analysis of individual genes due to low efficiency of both transformation and targeted integration. To improve the targeted gene disruption efficiency as well as to expedite gene disruption construct production, we used a short linear construct with minimal elements, an antibiotic resistance selectable marker gene, and a 250- to 600-bp-long partial target gene. The linear minimal element (LME) constructs consistently produced stable transformants for diverse categories of genes. Typically, 100% of the transformants were targeted gene disruption mutants when using the LME constructs, compared with inconsistent transformation and usually less than 10% targeted gene disruption with circular plasmid disruption constructs. Each mutant displayed a unique molecular signature thought to originate from endogenous exonuclease activities in fungal cells. Our data suggests that a DNA double-stranded break repair mechanism (DSBR) functions to increase targeting efficiency. This method is advantageous for high throughput gene disruption, overexpression, and reporter gene introduction within target genes, especially for asexual filamentous fungi where genetic approaches are unfavorable.

Acetylglucosaminidase↗

PubMed2006

Effect of indomethacin on Bfl-1, WISP-1 and proliferating cell nuclear antigen in colon cancer cell line HCT116 cells.

BACKGROUND: Non-steroidal anti-inflammatory drugs such as indomethacin can inhibit the growth of tumors through both the cyclooxygenase-2 (COX-2) dependant and COX-2 independent pathways, but the exact mechanism has not yet been shown. In our previous study, COX-2 independent proteins (Bfl-1, WISP-1 and proliferating cell nuclear antigens [PCNA]) in indomethacin-treated colorectal cancer cells with the use of proteomics technology had been identified. OBJECTIVES: To study and confirm the effect of indomethacin on the expression of Bfl-1, WISP-1 and PCNA in human colon cancer line HCT116 cells and the COX-2 independent tumor inhibiting pathway. METHODS: Human colon cancer cell line HCT116 cells were divided into a treatment with indomethacin (IC 50) group, and a treatment with dimethyl sulfoxide (DMSO) as a control group for 48 h. The expression of Bfl-1, WISP-1 and PCNA, mRNA and protein were determined by a real-time quantitative PCR and Western blot, respectively. RESULTS: Indomethacin down-regulated the expression of Bfl-1, WISP-1 and PCNA mRNA in vitro (9.53 +/- 0.15 vs 27.87 +/- 0.12, 7.37 +/- 0.58 vs 20.17 +/- 0.58, 5.17 +/- 0.06 vs 0.87 +/- 0.06). Indomethacin also down-regulated the expression of Bfl-1, WISP-1 and PCNA protein (40.01 +/- 1.61 vs 43.76 +/- 1.63, 22.50 +/- 1.17 vs 30.30 +/- 1.55, 17.69 +/- 1.18 vs 20.80 +/- 1.08). CONCLUSIONS: Inducing apoptosis and inhibiting proliferation contribute to the anticancer activity of indomethacin via COX-2 independent pathway of Bfl-1, WISP-1 and PCNA. This further confirms the results of our previous study.

Apoptosis↗

PubMed2006

Interleukin-10 promoter polymorphisms in patients with hepatitis B virus infection or hepatocellular carcinoma in Chinese Han ethnic population.

BACKGROUND: Since single nucleotide polymorphisms (SNPs) can serve as gene markers, polymorphism profiles may help scientists to identify the full collection of genes that contribute to the development of complex diseases such as cancer. The distribution of interleukin-10 (IL-10) promoter polymorphisms in Chinese Han ethnic patients with hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) was investigated in this study. METHODS: The polymorphisms of IL-10 promoter region were detected by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing. Sixty-six health controls, 42 patients with HBV infection, 30 HCC patients, and cell line SMMC-7721 were examined this way. RESULTS: Polymorphisms of T/C or T/N on -872 site occurred frequently in Han ethnic population. Polymorphisms were detected in HBV and HCC patients and cell line SMMC-7721. The hotspot among the polymorphisms was inserting base A between -1058 and -1057. CONCLUSION: Polymorphisms of IL-10 promoter in HBV and HCC patients may be associated with HBV infection and HCC development.

Asian People↗

PubMed2006

[Estrogenic effects of gasoline-fueled vehicle exhausts and methanol-fueled vehicle exhausts].

OBJECTIVE: To investigate the estrogenic effects of gasoline-fueled vehicle exhausts and methanol-fueled vehicle exhausts and provide a scientific basis for replacement of gasoline by methanol as fuel in vehicle. METHODS: The estrogen-like activities of gasoline-fueled vehicle exhausts and methanol-fueled vehicle exhausts were detected using the recombinant yeast estrogen system. RESULTS: The A600 value of gasoline-fueled vehicle exhausts was 0. 081 when the concentration of gasoline-fueled vehicle exhausts was 1000 mL/mL, and there were significantly statistical differences as compared with those of the dimethyl sulfoxide (DMSO) control group (P < 0.05), which indicated that such concentration had poisonous effects on yeast cell; when the concentration of gasoline-fueled vehicle exhausts was 31.25 mL/mL, the estrogen-like activities of gasoline-fueled vehicle exhausts could be detected, and there were significantly statistical differences as compared with those of the DMSO control group (P<0.05). Besides, the estrogen-like activities could not be detected in other groups with various concentrations. The estrogen-like activities of methanol-fueled vehicle exhausts could not be detected, and there were no significantly statistical differences in A600 value (P > 0.05) when each group was compared with the DMSO control group. CONCLUSION: Gasoline-fueled vehicle exhausts have weak estrogenic effects, whereas methanol-fueled vehicle exhausts have no such effects.

Air Pollution↗

PubMed2006

[Security of dual cancer-specific targeting vector and its cytotoxic effect when harbored].

BACKGROUND & OBJECTIVE: The xenograft tumor mass in nude mice could be completely eliminated using the targeting dual gene-virotherapy strategy. Now, the most important point is to improve its security. This study was to construct dual cancer-specific targeting adenovirus called TD55 to evaluate its security, and construct TD55-TRAIL to explore its antitumor effect. METHODS: Plasmid pTD55 was constructed through replacing E1A promoter with promoter of human telomerase reverse transcriptase and deleting E1B 55KD gene, and plasmid pTD55-TRAIL was constructed by inserting TRAIL gene into pTD55. Adenoviruses TD55 and TD55-TRAIL were obtained through homologous recombination in 293 cells. Cytotoxic effects of TD55 and TD55-TRAIL on human colon cancer cell lines SW620 and HCT116, human lung cancer cell line A549, and human embryonic lung cell lines MRC5 and WI38 were detected by crystal violet staining and MTT assay. Tumor cell apoptosis was detected by flow cytometry. RESULTS: Cytotoxic effects of TD55-TRAIL on MRC5 and WI38 cells were weaker than those of ZD55-TRAIL. The virus proliferation ability of ZD55-TRAIL in normal cells is 3-5 times stronger than those of TD55 and TD55-TRAIL. The apoptosis rate of TD55-TRAIL-infected SW620 cells was 3.3 times as high as that of TD55-infected SW620 cells. CONCLUSIONS: TD55-TRAIL has better security than ZD55-TRAIL in normal cells. So, the security of medication will be improved with dual targeting vector TD55. TD55-harbored gene as TD55-TRAIL has stronger effect than TD55 in inducing apoptosis of tumor cells.

Adenoviridae↗

PubMed2006

[The biological changes of NIH3T3 cells co-cultured with human bone morphogenetic protein-2 gene transfecting cells].

OBJECTIVE: To investigate the ultrastructure and the alkaline phosphatase (ALP) activity changes of NIH3T3 cells incubated with secretive human bone morphogenetic protein-2 (hBMP-2) that is induced by gene transfection through transwell system. METHODS: Eukaryotic expression vector (pcDNA3.1-B2) was transduced into NIH3T3 cells by Sofast, a positive compound transfection agent. The positive cell clones were selected with G418. The cytoplasmic and extracellular expression of BMP-2 in the NIH3T3 cells were determined by immunohistochemical and enzyme-linked immunosorbent assay (ELISA). NIH3T3 cells were co-cultured with hBMP-2 gene transfecting cells through transwell system, and the ultrastructure and ALP activity (the markers of osteogenetic differentiation) changes were observed. RESULTS: There were cytoplasmic and extracellular expression of BMP-2 in transfecting NIH3T3 cells. The ultrastructure changes and the high expression of ALP suggested the osteogenetic differentiation tendency of NIH3T3 cells co-cultured with transfecting NIH3T3 cells. CONCLUSIONS: Secretive BMP-2 that is induced by gene transfection could promote the osteogenetic differentiation of fibroblast cells.

Alkaline Phosphatase↗

PubMed2006

[Effects of Rehmannia glutinosa oligosaccharides on proliferation of 3T3-L1 adipocytes and insulin resistance].

OBJECTIVE: To investigate the influence of Rehmannia glutinosa oligosaccharides (ROS) on the proliferation of 3T3-L1 adipocytes and insulin resistance. METHOD: 3T3-L1 preadipocytes were cultured, the proliferation of 3T3-L1 preadipocytes was detected by MTT method. Insulin resistant 3T3-L1 adipocytes cell model was induced by dexamethasone and the change of glucose concentration in cell culture was determined after ROS treatment. RESULT: In the high glucose DMEM culture media, MTT method showed that the absorbance at 570nm of 3T3-L1 preadipocytes was increased and that of 3T3-L1 adipocytes was decreased. ROS significantly increased glucose consumption in 3T3-L1 preadipocytes and adipocytes culture in a concentration-dependent manner. ROS improved the sensitivity of 3T3-L1 adipocytes to insulin. CONCLUSION: ROS can promote the proliferation of 3T3-L1 preadipocytes, inhibite the proliferation of 3T3-L1 adipocytes, and also, significantly improve insulin resistance induced by dexamethasone.

3T3-L1 Cells↗

PubMed2006

[Systematic review of directly observed therapy on tuberculosis control in China].

OBJECTIVE: To evaluate the effectiveness of directly observed treatment (DOT) implementation in tuberculosis (TB) control in China. METHODS: Systematic literature review was carried out for published and unpublished articles regarding DOT, and meta analysis was used to compile results from selected papers. Also, sensitive analysis was carried out to explore the potential factors influencing the effectiveness of DOT. RESULTS: Two hundred and four articles were identified from China National Knowledge Infrastructure, Wanfang and Medline databases during 1994 - 2004 in which 120 articles were eligible according to our selection criteria. (1) Regarding TB case management: TB patients managed under DOT was compared to cases managed under the whole course treatment management (WCM). The combined RD of cure rate was 0.14 (95% CI: 0.06 - 0.22) and the two case management methods were significantly different (P < 0.00001). Data from stratified analysis showed that strict implementation of WMC had similar effectiveness with DOT (P = 0.06), and with RD 0.02 (95% CI: 0.00 - 0.03). However, the cure rate of DOT management was significantly better than that under un-strict WCM management (P < 0.05) with RD 0.16 (95% CI: 0.07 - 0.24). The cure rate of DOT was significantly better than those patients under self-administration (RD was 0.24 with 95% CI: 0.10 - 0.38 and P = 0.002). (2) Chemotherapeutics: when short-course and long course-treatments were compared, the combined RD became 0.04 (95% CI: 0.01 - 0.07) and P = 0.003. CONCLUSIONS: If the implementation was under strict management, the different models of patient management showed similar adherence rates. However, the effect of adherence would depend on the regimen, pattern of intake of the drugs and the methods of supervision being used.

China↗

PubMed2006

[Study of localization and translocation of human high mobility group protein B1 in eukaryotic cells].

OBJECTIVE: To observe the localization and translocation of human high mobility group protein B1 (HMGB1) protein in eukaryotic cells. METHODS: The vector that expressed the fusion protein of human HMGB1 and enhanced green fluorescent protein (EGFP) in mammalian cells were constructed. HMGB1 and EGFP were subcloned into hytohemagglutinin (HA) tagged vector pcDNA3-HA by two steps, the construct of which was then transfected into 293A cells and observed with fluorescence microscope. RESULTS: The recombinant plasmid was verified by enzyme digestion, polymerase chain reaction (PCR) and sequence analysis, and the fusion protein was highly expressed in 293A cells. With fluorescence microscopy the green fluorescence was found to be distributed in the nuclei. Eighteen hours after the stimulation with tumor necrosis factor-alpha (TNF-alpha), it was found to have translocated into the cytoplasm in some of the cells. CONCLUSION: The expression vector for HMGB1-EGFP fusion protein is successfully constructed and effectively expressed in mammalian cells, and it can serve as an important tool in the study of the signal pathway of HMGB1 in mammalian cells.

Cells, Cultured↗

PubMed2006

[Simultaneous determination of trace platinum, palladium and rhodium in environmental dust samples by ICP-MS after open-digestion].

A sensitive method for simultaneous determination of Pt, Pd and Rh in dust samples by ICP-MS after open-digestion was developed. The digestion method for the samples and conditions for measurement for ICP-MS were studied in detail. Aquaregia was proved to be a better solvent for the digestion of dust samples. Under the optimum conditions, the limits of detection of Pt, Pd and Rh were 0.48, 4.22 and 0.42 ng x g(-1), respectively. The proposed method was applied to the real sample analysis, and good recoveries were obtained. The recoveries of Pt, Pd and Rh were found to be between 87.6%-88%, 85.2%-87.8%, and 93%-95%, respectively.

English Abstract↗

PubMed2006

In utero transplantation of human hematopoietic stem/progenitor cells partially repairs injured liver in mice.

The aim of this study is to establish a novel mouse model with high achievement and chimerism by in utero transplantation of human hematopoietic stem/progenitor cells and to explore the possibility that human adult hematopoietic stem/progenitor cells can differentiate into hepatocyte-like cells and partially repair the liver damage induced by carbon tetrachloride (CCl(4)). Mononuclear cells (MNCs) were isolated from fresh human umbilical cord blood (hUCB) and CD34(+) cells were enriched from the MNCs by magnetic cell isolation. These cells were injected respectively into the fetal mice at 11-13 days of gestation. At one month after birth, the specific markers of human cells, human alpha-satellite sequence (h17alpha), CD14, CD34, CD45, and GPA were detected by PCR and FACS. At three and six months after birth, the established human-mouse chimeras were administered with CCl(4) by intraperitoneal injection. The biochemical markers (ALT, AST, ALP, albumin) in serum were determined and human hepatocyte-specific proteins, such as human albumin, hepatocyte nuclear factor-4, hepatocyte-specific antigen, tryptophan 2,3-dioxygenase and alpha fetoprotein were analyzed by PCR, RT-PCR, real-time PCR and immunohistochemistry staining, respectively. More than 77% of recipients demonstrated human-mouse chimera. Significantly, hUCB hematopoietic stem/progenitor cells may differentiate into human hepatocyte-like cells with evidence of the expression of human hepatocyte-specific proteins as well as partially repair or protect liver damage induced by CCl(4). The mouse model described in this article provides a useful tool for the studies of regeneration of human hepatocyte-like cells from adult hematopoietic stem/ progenitor cells as well as facilitates the therapeutic potential for liver diseases or damage by in utero transplantation.

Animals↗

PubMed2006

[Feeding preference of Plutella xylostella (Lepidoptera: Plutellidae) larva to its hosts].

The feeding experiment with different sorts of Brassica vegetable crops showed that Plutella xylostella larva preferred the seedlings of Chinese cabbage (Brassica campestris L.), radish (Raphanus sativus L.) and caixin (Brassica campestris L.) to those of rape (Brassica napus L.) and cabbage (Brassica olereacea L.), with a selection proportion of 93.33% and 6.67% between Chinese cabbage and rape, and of 16.67% and 83.33% between cabbage and caixin. On the whole, the feeding preference of P. xylostella larva was less related to the contents of soluble glucide and starch in the vegetables, but had a definite negative correlation to the content ratio of these compounds. The P. xylostella larva fed with Chinese cabbage and caixin grew better than that fed with rape and cabbage, and the feeding amount and body weight of per larva were 0.583 - 0.637 cm2 and 2.07 - 2.18 mg, respectively. The larva preferred damaged vegetable seedlings, too.

Adaptation, Physiological↗

PubMed2006

[In vitro and in vivo assesemet of sodium norcantharidin lipid microsphere].

AIM: To prepare lipid microsphere of sodium norcantharidin (NCTD) and then study their characters and pharmacokinetic behavior. METHODS: Dynamic Light Scattering, HPLC and retrodialysis technique were used to determine the in vitro characters of the NCTD loaded lipid microsphere (LM), such as the particle size, xi-potential, content, incorporation ratio, release profile and changes after dilute. And the plasma concentration was determined by HPLC-MS, compared with NCTD aqueous solution at the same time. RESULTS: Every property showed that the LM was preferable. The average diameter was about 200 nm. The xi-potential was - 38 mV. The content was close to 100%. And the incorporation ratio exceeded 80%. After i. v. administration of single dose, the pharmacodynamic parameter of LM AUC was 111.28 microg x mL(-1) x h(-1). The data of plasma concentrations showed that the NCTD LM was of two compartment. There was no obvious difference between in vivo parameters of LM and reference solution. CONCLUSION: The NCTD LM was eligible and the character of it in vivo was not changed.

Animals↗

PubMed2005

[Effects of secretive bone morphogenetic protein 2 induced by gene transfection on the biological changes of NIH3T3 cells].

BACKGROUND: Bone morphogenetic proteins (BMPs), which belong to the transforming growth factor beta superfamily, are powerful regulators of cartilage and bone formation. This study investigated the biological changes of NIH3T3 cells incubated with secretive BMP2 that was induced by gene transfection through transwell. METHODS: Eukaryonic expression vector (pcDNA3.1-B2) was transfered into NIH3T3 cells with Sofast, a positive compound transfection agent. The positive cell clones were selected with G418. The cytoplasmic and extracellular expressions of BMP2 were determined by immunohistochemical stain and enzyme-linked immunosorbent assay. NIH3T3 cells were co-cultured with hBMP2 gene transfecting cells through transwell, and the ultrastructure, alkaline phosphatase activity and the expression of osteocalcin (the marker of osteogenetic differentiation) changes were observed. RESULTS: There were cytoplasmic and extracellular expressions of BMP2 in transfecting NIH3T3 cells. The ultrastructural changes, the high activity of alkaline phosphatase and the positive stain of osteocalcin suggested the osteogenetic differentiation tendency of NIH3T3 cells co-cultured with transfecting NIH3T3 cells. CONCLUSION: Secretive BMP2 that is induced by gene transfection could promote the osteogenetic differentiation of fibroblast cells.

Alkaline Phosphatase↗

PubMed2005

Division and microstructure feature in the interface transition zone of Fe3Al/Q235 diffusion bonding.

The microstructure near a diffusion interface was studied by means of scanning electron microscopy and electron probe microscopy, and the results indicated that the interface transition zone of Fe3Al/Q235 dissimilar materials was composed of a diffusion interface, a mixed transition region, and A/B transition regions at the sides of the interface. Microstructures of the interface and base materials were interlaced to form the microstructure of layer characteristic. With increased heating temperature and holding time, the width of the Fe3Al/Q235 interface transition zone increased and the microstructure gradually became coarse. The microhardness in the diffusion transition zone was decreased and there was a peak value at the diffusion interface. The distribution of Al, Fe, and Cr in the interface transition zone was increased or decreased monotonically with some local concentration fluctuation. There was nearly no change in the concentration of C element near the interface.

Journal Article↗