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Biomedical subjects

Jing Dong

Publications and source records attributed to Jing Dong.

52 records · Page 3Linked to original sources
PubMed2004

[Effect of gamma-interferon on protein expressions of interleukin-4 and transforming growth factor-beta1 in experimental silicotic rats].

OBJECTIVE: To study the effect of gamma-interferon on the protein expressions of interleukin-4 (IL-4) and transforming growth factor-beta(1)(TGF-beta1) on silicotic rats. METHODS: Wistar rats were exposed to lower dose (20 mg) of quartz by intratracheal injection. Next day, the experimental rats were treated with gamma-interferon (1 x 10(5) IU) daily. Rats were killed in 1 month and 2 month to observe the changes of pathology of lung tissue by use of HE and VG staining, and the expressions of IL-4 and TGF-beta1 by use of immunohistochemical technique and quantitative analysis of protein expressions by image analysis system. RESULTS: (1) The fibrotic degree in silicotic lesions of rat lung was 1/2 approximately 1 grade less in IFN-gamma treated groups than in quartz controls. (2) Quantitative image analysis showed that the integrated optical density (IOD) of IL-4 positive cell in quartz controls in 1 month was (3.33 +/- 1.27) x 10(4) and decreased to (1.99 +/- 0.80) x 10(4) in 2 month, and that of TGF-beta1 positive cell increased from (3.67 +/- 0.63) x 10(4) to (4.90 +/- 1.11) x 10(4); The IOD of IL-4 positive cell in IFN-gamma treated groups was decreased from (2.19 +/- 0.90) x 10(4) to (0.61 +/- 0.22) x 10(4)(P < 0.05), and that of TGF-beta1 positive cell increased from (1.37 +/- 0.31) x 10(4) to (1.76 +/- 0.72) x 10(4) (P < 0.05). At these two time points, the IODof IL-4 and TGF-beta1 positive cell in IFN-gamma treated groups were lower than those in quartz controls (P < 0.05 or P < 0.01). CONCLUSION: gamma-interferon may inhibit the expressions of IL-4 and TGF-beta1 in silicotic rats.

Animals↗
PubMed2004

[Characterization of Me. PEG-PLA copolymer nanoparticles prepared by modified spontaneous emulsion-solvent evaporation].

AIM: Characterization of poly (D, L-lactic acid)/monomethylether terminated/polyethylene glycol (Me. PEG-PLA) block copolymers nanoparticles. METHODS: Me. PEG-PLA block copolymers were prepared by bulk polymerization. A series of nanoparticles were made from Me. PEG-PLA block copolymer by modified spontaneous emulsion-solvent evaporation technique. RESULTS AND CONCLUSION: The structure of copolymer was performed by means of 1HNMR and FT-IR. The morphological examination of nanoparticles was performed by means of atomic force microscope (AFM). Results indicated that nanoparticles exhibited a smooth spherulite and core-shell structure. The hydrophilic shell is consisted of PEG segments and hydrophobic core is consisted of PLA segments. Zeta potential of nanoparticles was zero and further indicated core-shell structure. The particle size and size distribution of nanoparticles were measured by laser light scattering technique. The effective particle size range was from 70 to 160 nm and showed a normal distribution.

Drug Carriers↗
PubMed2003

Fractionation and characterization of a Polysaccharide from the sclerotia of Pleurotus tuber-regium by preparative size-exclusion chromatography.

A kind of regenerated cellulose gel (RCG) particles were treated by toluene to obtain particles with smaller mean pore size, then was mixed with the cellulose gel with pore size of 370 and 525 nm. A preparative size-exclusion chromatography (SEC) column (700 x 20 mm) packed with three gel particles was used to fractionate water-soluble polysaccharide (WEP) extracted from the sclerotia of Pleurotus tuber-regium by aqueous solution. The exclusion limit and fractionation range of the stationary phase of the preparative SEC were molecular mass 8 x 10(5) and 5 x 10(3) to 8 x 10(5), respectively. The calibration curve of the preparative SEC was represented as: log M=13.96-0.53 Ve. The WEP sample (weight-average molecular mass M(w)=2.2 x 10(4), polydispersity=2.4) was divided into three fractions with M(w) ranging from 1.4 x 10(4) to 3.4 x 10(4) by the preparative SEC column, and the fractions were characterized by gas chromatography GC, SEC combined with laser light scattering (SEC-LLS) and viscometry. The unfractionated WEP exhibited triple peaks due to different molecular mass, but each fraction exhibited single peak with the polydispersity of 1.1-1.8 in the SEC patterns. The results indicated that the preparative SEC was efficient for fractionation of polysaccharides having low molecular weight and for determination of their molecular mass.

Chemical Fractionation↗
PubMed2003

Variations in IB1/JIP1 expression regulate susceptibility of beta-cells to cytokine-induced apoptosis irrespective of C-Jun NH2-terminal kinase signaling.

We previously reported that interleukin-1beta (IL-1beta) alone does not cause apoptosis of beta-cells, whereas when combined with gamma-interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), it exerts a distinct apoptotic effect. Studies in beta-cell lines indicated that IL-1beta reduced expression of islet brain (IB)-1/JNK interacting protein (JIP)-1, a JNK scaffold protein with antiapoptotic action. We examined whether variations in IB1/JIP-1 expression in purified primary beta-cells affect their susceptibility to cytokine-induced apoptosis. Exposure to IL-1beta for 24 h decreased cellular IB1/JIP-1 content by 66 +/- 17%; this IL-1beta effect was maintained in the presence of TNF-alpha + IFN-gamma, which did not influence IB1/JIP-1 levels by themselves. Addition of IL-1beta to TNF-alpha + IFN-gamma increased apoptosis from 20 +/- 2% to 59 +/- 5%. A similar increase in TNF-alpha + IFN-gamma-induced apoptosis was produced by adenoviral expression of antisense IB1/JIP-1 and was not further enhanced by addition of IL-1beta, indicating that IL-1beta-mediated suppression of IB1/JIP-1 in beta-cells increases their susceptibility to cytokine-induced apoptosis. However, adenovirally mediated overexpression of IB1/JIP-1 also potentiated TNF-alpha + IFN-gamma-induced apoptosis, suggesting that the antiapoptotic effect of IB1/JIP-1 depends on well-defined cellular levels. We conclude that the IB1/JIP-1 level in beta-cells can control their susceptibility to apoptosis independent of JNK signaling.

Adaptor Proteins, Signal Transducing↗
PubMed2003

[Synergetic transactivating effect of HCV core and HBV X proteins on SV40 early promoter/enhancer].

BACKGROUND: To investigate the synergetic transactivating effects of HCV core and HBV X proteins. METHODS: HCV core and HBV X protein-expressing plasmids were constructed with the vector pcDNA3.1(-). The plasmids were transfected into HepG2 cells and cotransfected Hep2 cells with reporter plasmid Psv-lacZ by lipofectamine plus reagents. The virus proteins produced in transient expression system were detected at the transcription and translation levels. The activity of b-galactosidase was detected, which reflected the transactivating function of the proteins. RESULTS: The expression of plasmids were detected in soluble protein cell extracts of transiently transfected HepG2 cells. HCV core protein activated the b-galactosidase expression at a value 4.9 times higher than the control, while HBV X protein activated at a value 3.5 times. It arrived at 9 times transfected with the plasmids simultaneously. The activating effect increased in relation to the amount of plasmids. CONCLUSIONS: The results suggested that the two kinds of virus proteins have transactivating effect on SV40 early promoter/enhancer, and they acted synergistically. These contribute to explain the mechanisms of liver injury or tumorigenesis induced by HCV or/and HBV infection.

Animals↗
PubMed2002

[The study on heterogeneity of hepatitis B virus DNA].

OBJECTIVE: To investigate the HBV quasispecies groups in the patients with chronic HBV infection. METHODS: Specific primers ware synthesized according to HBV strain found in China, the preC/C gene, reverse transcriptase region, whole S region, X gene and whole genome ware amplified by PCR method from the serum of 18 patients with chronic HBV infection, and then the PCR products were subcloned into pGEM Teasy vectors. Positive clones with target sequences were selected out for sequencing. Sequence comparison of the selected clones ware made to find the difference. RESULTS: The homology between clones from one patient of preC/C gene, reverse transcriptase of polymerase region, whole S region, X gene and whole genome are 98.0% approximately 99.1%, 98.7% approximately 99.3%, 97.5% approximately 100%, 93.0% approximately 98.2% and 96.6% approximately 97.5%, respectively. There was a high-frequency A83 substitution and core antigen internal deletion (CID) in preC/C region. Substitution, deletion and frame-shift by insertion or deletion of short sequence were found in 4 open reading frames. Deletion in X gene (Core promoter, CP) will not only result in the polymorphism of X protein at the carboxyl end, but also regulate the expression of HBeAg. Coding sequence of truncated middle surface antigen and defective HBV genome could also be detected in this study. CONCLUSION: There are HBV quasispecies groups in patients with chronic HBV infection. Hot deletion region in X region (CP) will influence the prognosis of the HBV infection. Individually characterized substitutions in amino acid sequence of viral protein is worthy of further study.

Amino Acid Sequence↗
PubMed2002

Mitogen-activated protein kinases contribute to reactive oxygen species-induced cell death in renal proximal tubule epithelial cells.

Extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNK/SAPK), and p38 mitogen-activated protein kinase (MAPK) were all rapidly activated in a ROS-dependent manner during 2,3,5-tris-(glutathion-S-yl)hydroquinone (TGHQ)-mediated oxidative stress and oncotic cell death in renal proximal tubule epithelial cells (LLC-PK1). TGHQ-induced phosphorylation of ERK1/2 and JNK MAPKs required epidermal growth factor receptor (EGFR) activation, whereas p38 MAPK activation was EGFR independent. In contrast to their established roles in cell survival, TGHQ-activated ERK1/2 and p38 MAPK (but not JNK) appear to contribute to cell death, since inhibition of ERK1/2 or p38 MAPKs with PD098059 or SB202190 respectively, attenuated TGHQ-mediated cell death. TGHQ increased AP-1 and NFkappaB DNA-binding activity, but whereas pharmacological inhibition of ERK1/2 or p38 MAPKs attenuated AP-1 DNA binding activity, it potentiated TGHQ-mediated NFkappaB activation. Consistent with a role for NFkappaB activation in the cytoprotective response to ROS in renal epithelial cells, an anti-NFkappaB peptide SN50 suppressed the protective effects of ERK inhibition (PD098059 treatment). The data provide evidence that the activation of MAPKs by ROS in renal epithelial cells plays an important role in oncotic cell death, and NF-kB is involved in the cytoprotective effects of PD098059.

Animals↗
PubMed2002

[Construction and expression of humanized anti-HBsAg scFv targeting interferon-alpha in escherichia coli].

OBJECTIVE: To develop a bacteria expression system to produce the fusion protein of humanized anti-HBsAg scFV and interferon-alpha. METHODS: The expression vector was constructed after cleaving the plasmids harboring the humanized anti-HBsAg scFv and interferon alpha respectively and ligating to linearized pET22b subsequence. The expression of fusion protein in E.coli was analyzed by SDS-PAGE. The binding activity and antiviral activity of the fusion protein was characterized by competing inhibition test and cytopathic effect reduction. RESULTS: The plasmid harboring the in frame arranged fusion gene was constructed and identified. After induction for 12h, a new band close to 4.5 10(4) was observed using SDS-PAGE. Results of competing ELISA and cytopathic effect reduction showed the fusion protein retained its specific binding activity and antiviral activities. CONCLUSIONS: The construction and expression of the fusion gene of humanized anti-HBsAg scFv and interferon in E.coli are successful.

Electrophoresis, Polyacrylamide Gel↗
PubMed2002

[Inducible expression of non-structural protein 3 of hepatitis C virus in E. coli].

BACKGROUND: To express recombinant non-structural protein 3 of hepatitis C virus (HCV) in E. coli. METHODS: The non-structural 3 (NS3) region DNA fragment of HCV was amplified by polymerase chain reaction (PCR) and inserted into inducible proeukaryotic expressive vector pET 30C(+)at Bam H1/EcoR1 sites. The competent BL21 (DE3) E.coli was transformed, and then cultured and induced with IPTG. The expressed HCV NS3 protein was confirmed with ELISA and dot blot hybridization using HCV NS3-specific single chain Fv (ScFv) antibody. RESULTS: 1 893 bp DNA fragment of HCV NS3 coding region was amplified by PCR technique. HCV NS3 expressive vector pET-NS3 was constructed. After transformation with pET-NS3 and induction with IPTG, recombinant HCV NS3 protein was expressed and confirmed by specific ELISA and dot blot hybridization. CONCLUSIONS: The recombinant HCV NS3 can be expressed in E. coli.

Escherichia coli↗
PubMed2002

[A preliminary study on the heterogeneity of preS2 region in hepatitis B virus].

OBJECTIVE: To investigate the mutation of the preS2 gene sequence of HBV and clarify the significance of HBV quasispecies groups in the patients with chronic HBV infection. METHODS: A set of specific primers were synthesized according to HBV DNA sequence of a Chinese strain. The preS2 gene region was amplified by PCR method from the sera of 51 patients with chronic HBV infection, and the PCR products from 5 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel electrophoresis (PAGE) was employed to display the deletion mutations, clones with differential length were selected and sequenced. Sequence comparison was made to find the difference. RESULTS: When analyzed by PAGE, 2 approximately 3 bands were displayed in the PCR products from 52.9% (27/51) patients. This phenomena of multiple bands in PAGE was detected in both HBeAg (36.1%) and anti-HBe (93.3%) positive patients, the difference between the 2 groups being statistically significant (P < 0.01). Analysis on deduced amino acid sequence showed the deletion mutations were in the N-terminal half of the preS2-encoded protein. CONCLUSION: There is a hot deletion region in preS2 gene sequence. These deletion mutations were more frequently found in patients with both anti-HBe and HBV DNA positivity. The deletion may influence the recognition by neutralizing antibodies. Our results suggest that there are HBV quasispecies in patients with chronic HBV infection.

Gene Deletion↗
PubMed2002

[Screening and cloning gene of hepatocyte protein interacting with hepatitis C virus core protein].

OBJECTIVE: To clone the unknown gene of hepatocyte protein interacting with hepatitis C virus core protein. METHODS: Using the yeast dual hybrid system 3, bait plasmids of hepatitis C virus core were constructed. After identifying hepatitis C virus core protein that could stably expressed in AH109 yeast strains, we performed yeast two hybrid by mating AH109 with Y187 that transformed with liver cDNA library plasmids pACT2 and then plated on quadrople dropout (QDO) medium and assayed for alpha-gal activity. The genes of yeast colonies that could grow on QDO and had alpha-gal activity were sequenced. RESULTS: Among the 30 positive colonies, we blasted the gene of the sixth colony; we coined human hepatitis C virus binding protein 6(Hu Hcbp6) with Genbank, realized that the Hu Hcbp6 shares as much as 98% homology with two cDNA without knowing functions. We have proved that Hu Hcbp6 could interact with hepatitis C virus core protein. CONCLUSIONS: Hepatitis C virus core binding protein (Hu Hcbp 6 Genbank number: AY032594) was successfully cloned and identified. The study partly paved the way for investigating physiological function of the Hu Hcbp6.

Cloning, Molecular↗
PubMed2002

[Quasispecies and variations of hepatitis B virus: core promotor region as an example].

OBJECTIVE: To investigate the HBV quasispecies groups in the patients with chronic HBV infection. METHODS: A set of specific primers was synthesized according to DNA sequence of HBV strain found in China. The whole core promoter (CP) region was amplified by PCR method from the sera of 3 patients with chronic HBV infection, and the PCR products were subcloned into pGEM Teasy vectors. The clones were randomly selected to be sequenced. Sequence comparison of the selected clones was made to find the difference. RESULTS: By comparison, it was found that each sequence of selected clones was different. The point mutation always occurred in TATA-like boxes, especially from T to C replacement on 184 site. There is a hot region (33.3% 5/15) in basic core promoter where deletion mutation frequently happened. CONCLUSIONS: There is a hot deletion region near DR I in CP. The replacement at 184 nt (T to C) in the third TATA-like box may influence the expression of pre-C/C protein. The sequencing results suggest that there are HBV quasispecies groups in chronically infected patients.

DNA, Viral↗
PubMed2002

Cloning and analysis of the genomic DNA sequence of augmenter of liver regeneration from rat.

OBJECTIVE: To search for genomic DNA sequence of the augmenter of liver regeneration (ALR) of rat. METHODS: Polymerase chain reaction (PCR) with specific primers was used to amplify the sequence from the rat genome. RESULTS: A piece of genomic DNA sequence and a piece of pseudogene of rat ALR were identified. The lengths of the gene and pseudogene are 1508 bp and 442 bp, respectively. The ALR gene of rat includes 3 exons and 2 introns. The 442 bp DNA sequence may represent a pseudogene or a ALR-related peptide. Predicted amino acid sequence analysis showed that there were 14 different amino acid residues between the gene and pseudogene. ALR-related peptide is 84 amino acid residues in length and relates closely to ALR protein. CONCLUSION: There might be a multigene family of ALR in rat.

Amino Acid Sequence↗
PubMed2002

Quasispecies groups in the core promoter region of hepatitis B virus.

OBJECTIVES: To investigate the mutation of the basic core promoter (BCP) of hepatitis B virus (HBV) and clarify the significance of HBV quasispecies groups in patients with chronic HBV infection. METHODS: A set of specific primers was synthesized according to the HBV DNA sequence of a Chinese strain. The BCP was amplified by PCR method from the serum of 40 patients with chronic HBV infection, and the PCR products of 2 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel electrophoresis (PAGE) was employed to display the deletion mutations, and clones with differential length were selected to be sequenced. Sequence comparison was made to find the difference. RESULTS: Two or three bands were displayed by PAGE in 60% patients. The results of sequence analysis showed that there are some kinds of mutations in the BCP region. The substitution always occurs in TATA-like boxes, especially from T to C on 140 site. The deletion mutations were detected in TA1, TA2 and TA3. The 8bp, 20bp deletion mutations frequently happened. CONCLUSIONS: There is a hot deletion region in the BCP. The deletion and the substitution in the TATA-like box may influence the expression of preC/C protein. The sequencing results indicate that there are HBV quasispecies groups in patients with chronic HBV infection.

Base Sequence↗
PubMedDate not supplied

Lateralization and catecholaminergic neuroimmunomodulation: prazosin, an alpha1/alpha2-adrenergic receptor antagonist, suppresses interleukin-1 and increases interleukin-10 production induced by lipopolysaccharides.

OBJECTIVE: The brain has previously been shown to asymmetrically modulate neurochemical, neuroendocrine and immune responses to lipopolysaccharides (LPS). As these responses are reversed by a chemical sympathectomy, it can be hypothesized that the asymmetry in the functioning of the sympathetic nervous system may be one of the mechanisms by which the brain hemispheres asymmetrically modulate immune reactivity. METHODS: The effects of prazosin, an alpha1/alpha2-adrenergic receptor antagonist, on the production of interleukin (IL)-1beta and IL-10 induced by LPS was studied in mice selected for their paw preference. RESULTS: Two hours after intraperitoneal injection of 5 microg of LPS, plasma levels of IL-1beta were higher in right-pawed mice as compared to left-pawed or ambidextrous animals. No lateralization effect was observed for LPS-induced plasma IL-10 levels. Prazosin, 10 mg/kg, injected intraperitoneally half an hour before LPS, reduced plasma levels of IL-1beta and abolished the effect of lateralization. By contrast, prazosin drastically increased plasma levels of IL-10 in response to LPS and the production of corticosterone in untreated controls. CONCLUSIONS: These results suggest that the catecholaminergic modulation of immune reactivity depends on lateralization. This work further demonstrates that prazosin is endowed with anti-inflammatory properties that may be considered side effects of this drug, which is widely prescribed in the treatment of hypertension.

Adrenergic alpha-Antagonists↗