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Biomedical subjects

Tao Hong

Publications and source records attributed to Tao Hong.

53 records · Page 3Linked to original sources
PubMed2003

Characterization of a novel rapidly growing Mycobacterium species associated with sepsis.

A rapidly growing mycobacterium was isolated five times from blood cultures from a 6-year-old female patient with relapsed pre-B-cell acute lymphocytic leukemia. All five isolates had identical nucleotide sequences for the first 500 bp of the 16S rRNA gene, indicative of a single species. High-performance liquid chromatography analysis of mycolic acids indicated that the species was similar to Mycobacterium smegmatis. Sequence analysis of the 16S rRNA gene (1,455 bp) for one isolate demonstrated that the species was closely related to Mycobacterium diernhoferi. Based on the phenotypic features and phylogenetic analysis, it was concluded that the isolates represented a novel rapidly growing Mycobacterium species. The name "Mycobacterium hackensackense" is proposed for this unique strain, 147-0552(T), which was deposited in the American Type Culture Collection as ATCC BAA-823(T).

Base Sequence↗
PubMed2003

[Expression of chemokine-like factor 2 (CKLF2) mRNA in the rat myocardium after myocardial infarction].

OBJECTIVE: To investigate the expression of chemokine-like factor 2 (CKLF2) mRNA in the rat myocardium after myocardial infarction (MI). METHODS: In a rat model of MI, the myocardium surrounding the infarcted area was used for RNA preparation at different time points. After RT, competitive polymerase chain reaction amplification was performed to assess the expression of rCKLF2 mRNA. SAS Kruskal-Wallis test was used for statistical comparisons. RESULTS: The gene expression of rCKLF2 at mRNA level was significantly increased in the myocardium surrounding the infarcted area 3 days, 1 week, 2 weeks after infarction. CONCLUSION: It is possible that CKLF2 contributes to the pathophysiological process and needs to be further investigated.

Animals↗
PubMed2003

[Sequencing of adenovirus type 7 vaccine strain fragment and characterization of the hexon encoding gene].

OBJECTIVE: To complete the full-length sequencing of the human adenovirus type 7 vaccine strain (Ad7v) for novel vector constructing. METHODS: The Ad7v DNA was digested with SalI and the 17.5-68.0 map unit (mu) fragment was cloned and sequenced. The homology of encoding sequence of Ad7v hexon to those of group A,C,D,E,F and other numbers of group B was accomplished with the software CLUSTAL.V. The three-dimensional structure of the Ad7v hexon was predicted with the RasMo12.71. RESULTS: The fragment contains 17,596 bp, part of E2 and late gene L1, L2 and L3 were encoded by this region. Polypeptide encoded by hexon gene lies in L3 region, which is composed of 934 amino acids. Multiple sequence alignment with the other nine known hexon protein sequences suggested that the variable sequences are mainly concentrated on seven regions, namely hypervariable regions (HVRs). The seven HVRs are related to type-specificity and group-specificity. The three-dimensional structure of the Ad7v hexon revealed that the variable regions are located in the I1 and I2 loops of the molecule mostly on the tower of the hexon. CONCLUSION: The full-length genome sequencing of Ad7v was accomplished at last. Since the deduced amino acid sequence of Ad7v hexon was quite different from other adenoviral vectors such as Ad5 and Ad2, this virus can be potentially used for the construction of novel gene delivery vectors to counterpart the immunity to the vectors widely used at present.

Adenovirus E3 Proteins↗
PubMed2002

Suppression of N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis in F344 rats by resveratrol.

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural product occurring in grapes and various other plants with medicinal properties associated with reduced cardiovascular disease and reduced cancer risk. To evaluate the possibility and potential mechanism(s) of which resveratrol inhibits N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal tumorigenesis, 96 F344 male rats were divided into 10 groups and resveratrol (1 and 2 mg/kg) was administered orally or intraperitoneally (i.p.). In the groups in which resveratrol was administered at 2 mg/kg (orally, for 16 weeks), 1 and 2 mg/kg (i.p., for 16 weeks) and 1 mg/kg (i.p., for 20 weeks), the number of NMBA-induced esophageal tumors per rat was significantly reduced to 78, 62, 54 and 48, respectively (P < 0.05), and the size of maximum tumors in each group with resveratrol treatment was also significantly smaller than that in NMBA alone group (P < 0.05). Although the pathological examination did not indicate significantly decreased incidence of carcinomas by administering resveratrol, the tendency of carcinogensis suppression was observed (P = 0.177). Semi-quantitative RT-PCR and ELISA analysis demonstrated that following NMBA treatment, the expression of COX-1 mRNA was strongly present in tumor tissues, while weakly present in non-tissues; the expression of COX-2 mRNA was induced in both tumor and non-tumor tissues. The production of prostaglandin E(2) (PGE(2)) increased approximately 6-fold, compared with the normal esophageal mucosa. The higher expression of COX-1, the up-regulated COX-2 expression and the increased levels of PGE(2) synthesis were all significantly decreased by administering resveratrol. Our study suggests that resveratrol suppressed NMBA-induced rat esophageal tumorigenesis by targeting COXs and PGE(2), and therefore may be a promising natural anti-carcinogenesis agent for the prevention and treatment of human esophageal cancer.

Animals↗
PubMed2002

Clinicopathological significance of human macrophage metalloelastase expression in esophageal squamous cell carcinoma.

OBJECTIVE: Human macrophage metalloelastase is referred to as matrix metalloproteinase (MMP-12), its function in tumors is contradictory. The current study was undertaken to investigate the role of MMP-12 in esophageal squamous cell carcinoma (SCC). PATIENTS AND METHODS: We analyzed the levels of MMP-12 mRNA expression in 67 patients with primary esophageal SCC by Northern blot analysis and the tissues were subjected to in situ hybridization analysis for MMP-12. Immunohistochemical staining was performed to detect the macrophages infiltrated in esophageal SCCs. RESULTS: MMP-12 mRNA was detected in 27 of 67 esophageal SCC samples by Northern blot analysis. In situ hybridization and immunohistochemical staining revealed that MMP-12 mRNA signals are located mainly in tumor cells. The frequency of lymph node metastasis was significantly higher in the MMP-12-positive (MMP-12(+)) subgroup than MMP-12-negative (MMP-12(-)) subgroup (p < 0.05); furthermore, invasion was significantly deeper in the MMP- 12(+) subgroup than in the MMP-12(-) subgroup (p < 0.01). MMP-12 mRNA was inversely correlated with prognosis (p < 0.05). However, Cox multivariate analysis revealed that upregulation of MMP-12 was not related to prognosis. CONCLUSIONS: MMP-12 gene expression was associated with the progression of esophageal SCC; however, it was not an independent prognostic factor.

Aged↗
PubMed2002

Use of cutting balloons in coronary interventions.

OBJECTIVE: To study the efficacy and safety of cutting balloons in coronary interventions. METHODS: Twenty-two patients with 23 narrowed coronary arteries and 25 lesions enrolled the study, 17 of whom had 18 diseased coronary arteries and 18 lesions were in-stent restenosis. The average time from previous stenting was 7.60 +/- 3.53 months. The lesions were dilated with cutting balloons. RESULTS: All of the lesions were dilated successfully by 5.16 +/- 2.30 inflations of a cutting balloon. The mean total duration of balloon inflation was 233.96 +/- 94.83 seconds at pressures up to 9.40 +/- 1.96 bars. The severity of vascular stenosis was lessened substantially (89.64 +/- 8.65% vs 17.60 +/- 17.15%, P = 0.000) without severe complications. Three restenotic lesions were further dilated with conventional balloons, another one was stented again because of a dissection distal to the previous stent. Three primary lesions were stented for dissection or residual stenosis. Angina pectoris reoccurred in two patients in a mean follow-up period of 7.42 +/- 6.87 (range 0.5-20) months. CONCLUSION: Cutting balloon dilation is an effective and safe choice in interventions for coronary disease especially for in-stent restenosis.

Adult↗
PubMed2002

[Detection of the expression of alpha3-integrin on hantavirus permissive cells].

BACKGROUND: To express and purify human alpha3-integrin to serve as the antigen to prepare its antibody and to separate the Vero cell clones without expression of alpha3-integrin. METHODS: The human alpha3-integrin gene was amplified by using RT-PCR, then subcloned into a pQE30 expression vector and expressed in E. coli. The gene expression was confirmed by Western blot assay. Rabbit was inoculated with purified antigen to stimulate the antibody generation. The target Vero cells were separated by negative selection using antibody plus complement mediated cytolysis. The separated cell clones were confirmed by immunofluorescence and Western blot assay. RESULTS: The alpha3- integrin gene was cloned and expressed effetively, Western blot assay revealed that the expressed protein held good immune reactivity. High titer antibody was generated. However the expression of alpha3-integrin was not detected on Vero, VeroE6, Hep-2, 2BS and 293 cells. CONCLUSIONS: The results of the study suggested that hantavirus has other receptors on Vero cells beside alpha 3-integrin.

Animals↗
PubMed2002

[Expression of the main structural antigen VP6 of human rotavirus by recombinant adenovirus and immune responses induced in vivo].

BACKGROUND: Constructing replication defective recombinant adenovirus vector expressing the group specific antigen VP6 of human rotavirus and studying the immune responses induced in vivo. METHODS: The cDNA of full length VP6 was inserted into the adenovirus vector pShuttle-CMV, and recombinant adenovirus genome DNA was obtained through homological recombination in E.coli,then the recombinant adenovirus was gained after transfecting 293 cell line with the genome DNA. Gene integration of VP6 in resultant adenovirus was confirmed by PCR and Southern blot, respectively gene expression was confirmed in 293 cells by Western blot. BALB/c mice were immunized intranasally(inl)and orally(ora), respectively, to test the immunization effects of the adenovirus. RESULTS: Recombinant adenovirus named rvAd-VP6 was obtained. The cDNA of VP6 was integrated in the adenovirus and was able to be expressed in 293 cells stably. The systemic immune responses to rotavirus VP6 could be induced effectively in both oral and intranasal group, the titer of serum IgG antibody in the two group of mice were 1?1 000 and 1?10 000-1?100 000, respectively. In addition to IgG, the serum IgA specific to VP6 could also be detected at a titer of 1?10-1?100. Secretory IgA(sIgA) was detected in both lung lavage fluid and intestinal homogenate when administered intranasally to BALB/c mice, whereas only found in intestinal homogenate in the oral group. The results indicated that the immunization efficacy of intranasal inoculation was superior to that of oral inoculation. CONCLUSIONS: The recombinant adenovirus vector expressing human rotavirus VP6 was successfully constructed, its ability to induce immune responses has laid a solid foundation for the development of rotavirus genetically engineering vaccine against rotavirus infection.

Adenoviridae↗
PubMed2002

Insulin sensitivity and the diffuseness of coronary artery disease in humans.

OBJECTIVE: To study the relationship between insulin sensitivity and diffuse coronary artery disease. METHODS: Ninety-two consecutive patients underwent coronary angiography were enrolled in the study. Relationships between the results of angiograms and both glucose tolerance and blood lipids were analyzed. RESULTS: The mean age of the 92 patients (70 males, 22 females) was 65.4 +/- 6.3 y. In the 78 patients diagnosed by angiography as coronary artery disease, diffuse lesion was more common in diabetic patients than in those without a diabetes history (12/13 vs 24/65, P = 0.00026). Fasting glucose [(6.06 +/- 2.43) x 10(-3) mol/L vs (4.80 +/- 1.47) x 10(-3) mol/L, P = 0.009], glucose levels at one hour [(12.37 +/- 4.38) x 10(-3) mol/L vs (9.10 +/- 3.97) x 10(-3) mol/L, P = 0.001], two hours [(11.12 +/- 5.64) x 10(-3) mol/L vs (7.49 +/- 4.29) x 10(-3) mol/L, P = 0.003] and three hours [(8.11 +/- 5.51) x 10(-3) mol/L vs (5.56 +/- 3.46) x 10(-3) mol/L, P = 0.020] after food were higher in patients with diffuse coronary disease than in those with non-diffuse coronary disease. Differences in the insulin sensitivity index (ISI) between the two groups was statistically significant (-4.36 +/- 0.52 vs -3.89 +/- 0.69, P = 0.003). The incidence of multiple-vessel disease in diabetic patients was higher than that in non-diabetic patients (12/13 vs 33/65, P = 0.00565). Glucose levels at two hours [(10.22 +/- 5.57) x 10(-3) mol/L vs (7.67 +/- 4.43) x 10(-3) mol/L, P = 0.034] and three hours [(7.90 +/- 5.47) x 10(-3) mol/L vs (5.22 +/- 2.79) x 10(-3) mol/L, P = 0.007] after food were higher in patients with multiple-vessel disease than in those with single-vessel disease. Impaired insulin sensitivity without a history of diabetes mellitus was commonly seen in patients with coronary artery disease. CONCLUSIONS: The diffuseness of coronary artery disease is associated with insulin sensitivity and blood glucose levels. Insulin resistance is a common phenomenon in non-diabetic patients.

Aged↗
PubMed1998

High-level Expression and Characterization of the Fusion Protein Consisting of Diphtheria Toxin and Human Interleukin 6.

Diphtheria toxin is a single chain exotoxin of 535 amino acids, secreted from beta Corynebacteriophage diphtheriae. Eukaryotic cells, especially tumor cells are very sensitive to DT. Just one or two molecules of DT can kill a cell. On the surface of some tumor cells, such as human myeloma, heptoma, etc, IL-6 receptor has been demonstrated to be expressed at a very-high level. Selective cytotoxicity mediated by IL-6 receptor could be useful in the targeting therapy of these tumors. Based on this strategy, a hybrid protein consisting of DT and IL-6 was constructed, expressed and characterized. IL-6 cDNA was first modified for constructing the fusion protein of DT/IL-6 and the receptor binding domain of DTDNA was replaced by IL-6 cDNA to obtain the expression vector pdeltaDT/TL-6. After induction by IPTG, the fusion protein was expressed successfully, accounting for 20% of the total bacterial protein. The results of SDS-PAGE and Western blot showed that there was a band of about 64 kD. After preliminary purification, the IL-6 receptor competitive binding test and the cytotoxic activity assay of the deltaDT/TL-6 showed that the fusion protein possessed significant cytotoxic activity to U266 cells; while the cells expressing IL-6 receptors at a medium-level was resistant it to a certain degree.

Journal Article↗
PubMedDate not supplied

Roles for Rho/ROCK and vinculin in parietal endoderm migration.

The first cell migration event in the mouse embryo is the movement of parietal endoderm cells from the surface of the inner cell mass facing the blastocoel cavity to line the inner surface of the trophectoderm. F9 embryoid bodies provide an in vitro model for this event. They have an inner core of undifferentiated stem cells surrounded by an outer visceral endoderm layer. When plated on a laminin coated substrate, visceral endoderm transitions to parietal endoderm and migrates onto the dish, away from the attached embryoid body. We now show that this outgrowth contains abundant focal complexes and focal adhesions, as well as lamellipodia and filopodia. Treatment with the ROCK inhibitor Y-27632 promotes a 2-fold increase in outgrowth, and a transition from focal adhesions and associated stress fibers, to focal complexes and a decrease in stress fibers. ROCK inhibition also leads to an increase in lamellipodia. Inhibition of RhoA by transfection of a vector encoding C3 transferase, direct administration of the C3 enzyme, or transfection of a vector encoding p190 Rho GTPase Activating Protein also promotes outgrowth and an apparent transition from focal adhesions to focal complexes. Parietal endoderm outgrowth generated using vinculin-deficient F9 stem cells migrates 2-fold further than wild type cultures, but this outgrowth retains the morphology of wild type parietal endoderm, including focal adhesions and stress fibers. Addition of Y-27632 to vinculin-null outgrowth cultures further stimulates migration an additional 2-fold, supporting the conclusion that Rho/ROCK and vinculin regulate parietal endoderm outgrowth by distinct pathways.

ADP Ribose Transferases↗
PubMedDate not supplied

Comparison of three myofibroblast cell sources for the tissue engineering of cardiac valves.

The objective of this study was to evaluate the capacity of three clinically useful tissue sources: tricuspid valve leaflet (TVL), carotid artery (CA), and jugular vein (JV), to generate myofibroblasts for potential use in a tissue-engineered cardiac valve replacement. Tissue biopsies of clinically appropriate sizes obtained from juvenile sheep were used for this work. Cells obtained from all three tissue sources exhibited a myofibroblast phenotype in vitro, as demonstrated by their immunoreactivity with antibodies directed against vimentin, alpha-smooth muscle actin, fibronectin, and chondroitin sulfate. Protein synthesis characteristics were defined for the key extracellular matrix components: collagen, glycosaminoglycans, and elastin. Among the three sources, JV generated the highest numbers of cells, and JV cells produced the largest amount of collagen per cell. These data suggest that venous tissue, with its relative ease of accessibility, may generate myofibroblasts potentially useful for the interstitial cellular component of a tissue-engineered cardiac valve.

Actins↗
PubMedDate not supplied

Numerical and experimental research on the near-field optical virtual probe.

A near-field optical virtual probe (NFOVP) is a type of immaterial tip based on the principle of near-field evanescent wave interference. Evanescent wave interference and the aperture type play very significant roles in generating near-field optical virtual probes. Two evanescent waves, propagating in opposite directions, will interfere to generate the confinement field. The central peak of the wave distribution carries the preponderance of energy. An aperture can be used to suppress the sidelobe in the energy distribution while forming the NFOVP. In this paper, the NFOVP is investigated numerically by means of the three-dimensional (3-D) finite-difference time-domain (FDTD) method. Some significant factors in the creation of the NFOVP, such as the shape and size of the aperture, the incident light, and the specimen (nanoparticle), are studied and discussed. The optical field of the evanescent wave interference has been measured by near-field scanning optical microscopy (NSOM), and the preliminary experimental results are shown.

Journal Article↗