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Biomedical subjects

Hao Tang

Publications and source records attributed to Hao Tang.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Study on the changes in serum leukotrienes B4 and p38 mitogen activated protein kinase in multiple organ dysfunction syndrome].

OBJECTIVE: To investigate the changes in serum leukotrienes B4(LTB4) and p38 mitogen activated protein kinase (p38 MAPK) in multiple organ dysfunction syndrome (MODS) and to evaluate the relationship between LTB4 and p38 MAPK and clinical condition of patients with MODS. METHODS: The clinical condition of 26 patients with MODS was evaluated with scoring system. The serum LTB4 and p38 MAPK of the said patients and that of 12 healthy individuals were determined with enzyme linked immunoadsorbent assay(ELISA). The correlation of the scores of MODS and levels of serum LTB4 and p38 MAPK was analyzed. The correlation of the scores of MODS and levels of serum LTB4 and p38 MAPK was analyzed in non-survivors and survivors. RESULTS: The serum level of LTB4[(923.96+/-308.65)ng/L] was significantly lower in MODS patients compared with control group [(2 453.31+/-400.93)ng/L, P<0.05]. There was no significant difference in serum level of p38 MAPK between the patients with MODS [(193.83+/-106.32)ng/L]ls and control group [(124.36+/- 84.50)ng/L, P>0.05]. There was significant difference in the serum level of LTB4 between the survivors[(1 334.51+/-530.35)ng/L] and non-survivors [(444.98+/-206.30)ng/L, P<0.05]. There were significant negative correlations between serum LTB4 and MODS scores (P<0.001). CONCLUSION: The pathophysiological changes in later period of MODS are different from those of other common inflammatory responses. Serum LTB4 and p38 MAPK could be one of the indexes of the severity and prognosis on MODS.

Adolescent↗
PubMed2004

Netrin requires focal adhesion kinase and Src family kinases for axon outgrowth and attraction.

Although netrins are an important family of neuronal guidance proteins, intracellular mechanisms that mediate netrin function are not well understood. Here we show that netrin-1 induces tyrosine phosphorylation of proteins including focal adhesion kinase (FAK) and the Src family kinase Fyn. Blockers of Src family kinases inhibited FAK phosphorylation and axon outgrowth and attraction by netrin. Dominant-negative FAK and Fyn mutants inhibited the attractive turning response to netrin. Axon outgrowth and attraction induced by netrin-1 were significantly reduced in neurons lacking the FAK gene. Our results show the biochemical and functional links between netrin, a prototypical neuronal guidance cue, and FAK, a central player in intracellular signaling that is crucial for cell migration.

Analysis of Variance↗
PubMed2004

Amperometric glucose biosensor based on adsorption of glucose oxidase at platinum nanoparticle-modified carbon nanotube electrode.

A new amperometric biosensor, based on adsorption of glucose oxidase (GOD) at the platinum nanoparticle-modified carbon nanotube (CNT) electrode, is presented in this article. CNTs were grown directly on the graphite substrate. The resulting GOD/Pt/CNT electrode was covered by a thin layer of Nafion to avoid the loss of GOD in determination and to improve the anti-interferent ability. The morphologies and electrochemical performance of the CNT, Pt/CNT, and Nafion/GOD/Pt/CNT electrodes have been investigated by scanning electron microscopy, cyclic voltammetry, and amperometric methods. The excellent electrocatalytic activity and special three-dimensional structure of the enzyme electrode result in good characteristics such as a large determination range (0.1-13.5mM), a short response time (within 5s), a large current density (1.176 mA cm(-2)), and high sensitivity (91mA M(-1)cm(-2)) and stability (73.5% remains after 22 days). In addition, effects of pH value, applied potential, electrode construction, and electroactive interferents on the amperometric response of the sensor were investigated and discussed. The reproducibility and applicability to whole blood analysis of the enzyme electrode were also evaluated.

Aspergillus niger↗
PubMed2004

Inhibition of wild-type and mutant Bcr-Abl by AP23464, a potent ATP-based oncogenic protein kinase inhibitor: implications for CML.

The deregulated, oncogenic tyrosine kinase Bcr-Abl causes chronic myeloid leukemia (CML). Imatinib mesylate (Gleevec, STI571), a Bcr-Abl kinase inhibitor, selectively inhibits proliferation and promotes apoptosis of CML cells. Despite the success of imatinib mesylate in the treatment of CML, resistance is observed, particularly in advanced disease. The most common imatinib mesylate resistance mechanism involves Bcr-Abl kinase domain mutations that impart varying degrees of drug insensitivity. AP23464, a potent adenosine 5'-triphosphate (ATP)-based inhibitor of Src and Abl kinases, displays antiproliferative activity against a human CML cell line and Bcr-Abl-transduced Ba/F3 cells (IC(50) = 14 nM; imatinib mesylate IC(50) = 350 nM). AP23464 ablates Bcr-Abl tyrosine phosphorylation, blocks cell cycle progression, and promotes apoptosis of Bcr-Abl-expressing cells. Biochemical assays with purified glutathione S transferase (GST)-Abl kinase domain confirmed that AP23464 directly inhibits Abl activity. Importantly, the low nanomolar cellular and biochemical inhibitory properties of AP23464 extend to frequently observed imatinib mesylate-resistant Bcr-Abl mutants, including nucleotide binding P-loop mutants Q252H, Y253F, E255K, C-terminal loop mutant M351T, and activation loop mutant H396P. AP23464 was ineffective against mutant T315I, an imatinib mesylate contact residue. The potency of AP23464 against imatinib mesylate-refractory Bcr-Abl and its distinct binding mode relative to imatinib mesylate warrant further investigation of AP23464 for the treatment of CML.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Establishment and characterization of human hepatocellular carcinoma cell line FHCC-98.

AIM: To establish a novel human hepatocellular carcinoma (HCC) cell line FHCC-98 from HCC tissue and to provide a suitable model for studying HCC occurrence, progress and metastasis. METHODS: Serially passaged cells were cultured and their morphologies were observed under light and electron microscope. Cytogenetic study was conducted by using flow cytometry and chromosome analysis. Expressions of tumor markers such as alpha-fetoprotein (AFP), cytokeratin (CK) and hepatoma metastasis-associated factor HAb18G/CD147 on the FHCC-98 cells were detected by immunocytochemistry or Western blotting. Lactic dehydrogenase (LDH) isoenzymes were detected by polyacrylamide gel electrophoresis (PAGE). Xenograft was performed by inoculating FHCC-98 cells into the flanks of nude mice. RESULTS: Morphology of FHCC-98 cells was the same as that of other malignant cells. The expressions of the cells were positive for HAb18G/CD147 and CK, and negative for AFP. Its population doubling time was 21.4 h. The cell DNA was tetraploid and the major chromosomes were triploid by cytogenetics analysis. The tumorigenicity in nude mice was 100%. PAGE showed four bands representing LDH2, LDH3, LDH4 and LDH5. CONCLUSION: FHCC-98 is a novel HCC cell line and an ideal cell model for further exploring the mechanism of hepatocellular carcinoma invasion and metastasis.

Adult↗
PubMed2004

High dispersion and electrocatalytic properties of platinum nanoparticles on graphitic carbon nanofibers (GCNFs).

Highly dispersed platinum nanoparticles were electrodeposited on graphitic carbon nanofibers (GCNFs) by cyclic voltammetry (CV) in 7.7 mM H2PtCl6+0.5 M HCl aqueous solutions. The graphitic carbon nanofibers (GCNFs) used in this paper were grown directly on a graphite disk by chemical vapor deposition (CVD). The micrographs and element composition of Pt/GCNFs/graphite electrode were characterized by scanning electron microscopy (SEM) and electron diffraction spectroscopy (EDS). The electrocatalytic properties of Pt/GCNFs/graphite electrode for methanol oxidation have been investigated by CV and excellent electrocatalytic activity can be observed even at very low platinum loading (md=8.79 microg cm(-2)). The highest mass activity (MA) for methanol oxidation reaches 323 Ag(-1) when Pt/GCNFs/graphite electrode was cycled at a sweep rate of 50 mVs(-1) by CV in 2 M CH3OH+1 M H2SO4 aqueous solutions. This may be attributed to the small particle size and high dispersion of platinum particles coated on GCNFs and shows good potential application in direct methanol fuel cell (DMFC). Additionally, the long-term cycling stability of platinum catalysts was also investigated.

Journal Article↗
PubMed2004

Fever of recombinant human interferon-alpha is mediated by opioid domain interaction with opioid receptor inducing prostaglandin E2.

We have reported that there are distinct domains in Interferon-alpha (IFNalpha) molecule mediating immune and opioid-like effects respectively. And the opioid effect of IFNalpha is mediated by mu opioid receptor. We report here the structural basis of fever induced by recombinant human IFNalpha. Two kinds of IFNalpha mutants were obtained and used to investigate the structural basis of fever of IFNalpha, which are 129Ser-IFNalpha and 38Leu-IFNalpha. The antiviral activity of 129Ser-IFNalpha almost disappeared, but there still retained the strong analgesic activity. The antiviral activity of 38Leu-IFNalpha remained, but the analgesic activity disappeared completely. It showed that IFNalpha and 129Ser-IFNalpha decreased cAMP production, induced the fever, and stimulated PGE2 to release from the hypothalamus slices, which could be blocked by naloxone, but 38Leu-IFNalpha failed. It is the first demonstration that fever induced by IFNalpha is mediated by opioid domain of IFNalpha interacting with opioid receptor. It is inferred that high-activity and low side-effect IFNalpha or other cytokines could be obtained after being changed the motifs in the tertiary structure.

Animals↗
PubMed2004

Cigarette smoking among lesbians, gays, and bisexuals: how serious a problem? (United States).

INTRODUCTION: Population-based health surveys seldom assess sexual orientation, which results in the absence of a reliable measure of smoking among lesbians, gays, and bisexuals (LGB), a population perceived to have higher risks of tobacco-related diseases. This is the first study to compare the cigarette smoking rate of LGB with that of heterosexual individuals using a population-based sample with both male and female adults, and to identify which sub segments of LGB population are particularly burdened by tobacco use. METHODS: California Health Interview Survey (CHIS), a population-based telephone survey was used to assess smoking prevalence and its correlates among respondents. Of 44,606 respondents, 343 self-identified as lesbian; 593 self-identified as gay; and 793 identified themselves as bisexual (511 female and 282 male). Statistical analysis was performed using SAS and SUDAAN. RESULTS: Lesbians' smoking rate (25.3%), was about 70% higher than that of heterosexual women (14.9%) Gay men had a smoking prevalence of 33.2%, comparing to heterosexual men (21.3%). After controlling for demographic variables, logistic regression analysis showed that lesbians and bisexual women were significantly more likely to smoke compared with heterosexual women (OR = 1.95 and OR = 2.08, respectively). Gay men were also significantly more likely to smoke than heterosexual men (OR = 2.13; 95% CI = 1.66-2.73). Being 35-44-years-old, non-Hispanic White, and having low-education attainment and low-household income were common demographic predictors of cigarette smoking among LGB. CONCLUSION: Our study provides the strongest evidence to date that lesbians, bisexual females, and gay men had significantly higher cigarette smoking prevalence rates than their heterosexual counterparts.

Adolescent↗
PubMed2004

[Analysis of the status of diagnosis of acute pulmonary embolism and a study of further strategy to improve the diagnostic level].

OBJECTIVE: To analyze the present status of diagnosis of pulmonary embolism (PE) by analyzing the clinical data of patients admitted during last 10 years to our hospital, in order to look for a significant diagnostic strategy to improve the diagnostic level. METHODS: The data of patients diagnosed to have PE in last 10 years were analyzed. In the last 5 months, the patients suspected to have PE were diagnosed by a comprehensive approach including clinical manifestations, lung scan and/or spirals computer tomography (SCT) in our emergency department. RESULTS: The diagnostic rate, the final diagnostic rate within 3 days and the diagnostic rate by lung scan or/and SCT were all higher in the last 3 months than ever. The proportions of angiograms and the overall 3-month PE risk were 2.8% and 0. CONCLUSION: The comprehensive approach which includes clinical manifestations, lung scan and/or SCT can obviously improve the diagnostic level of PE.

Adolescent↗
PubMed2004

[Comparative studies of serological typing and HLA-A, B antigen genotyping with PCR using sequence-specific primers].

OBJECTIVE: To evaluate the accuracy of PCR with sequence-specific primers (PCR-SSP) for HLA-I genotyping and analyze the causes of the errors occurring in the genotyping. METHODS: DNA samples and were obtained from 34 clinical patients, and serological typing with monoclonal antibody (mAb) and HLA-A and, B antigen genotyping with PCR-SSP were performed. RESULTS: HLA-A and, B alleles were successfully typed in 34 clinical samples by mAb and PCR-SSP. No false positive or false negative results were found, and the erroneous and missed diagnosis rates were obviously higher in serological detection, being 23.5% for HLA-A and 26.5% for HLA-B. Error or confusion was more likely to occur in the antigens of A2 and A68, A32 and A33, B5, B60 and B61. CONCLUSIONS: DNA typing for HLA-I class (A, B antigens) by PCR-SSP has high resolution, high specificity, and good reproducibility, which is more suitable for clinical application than serological typing. PCR-SSP may accurately detect the alleles that are easily missed or mistaken in serological typing.

Antibodies, Monoclonal↗
PubMed2003

Neuronal repellent Slit2 inhibits dendritic cell migration and the development of immune responses.

One of the essential functions of dendritic cells is to take up Ags in peripheral tissues and migrate into secondary lymphoid organs to present Ags to lymphocytes for the induction of immune responses. Although many studies have demonstrated that the migration of dendritic cells is closely associated with the development of immune responses, little is known about factors that inhibit dendritic cell migration and control the extent of immune responses to Ag stimulation. We show that Slit2, a neuronal repellent factor, is up-regulated in the skin by allergen sensitization and down-regulates the migration of Langerhans cells. The effect is mediated by direct interaction of Slit2 with cells that express a Slit-specific receptor, Robo1. Slit2-mediated inhibition of Langerhans cell migration results in suppression of contact hypersensitivity responses. These findings provide insights into a novel mechanism by which Slit2 functions as an anti-inflammatory factor for the initiation of immune responses.

Animals↗
PubMed2003

Probing the different stages in contacting a single molecular wire.

A crucial problem in molecular electronics is the control of the electronic contact between a molecule and its electrodes. As a model system, we investigated the contact between the molecular wire group of a C90H98 (Lander) molecule and the edge of a Cu(111) monatomic step. The reproducible contact and decontact of the wire was obtained by manipulating the Lander with a low temperature scanning tunneling microscope. The electronic standing wave patterns on the Cu(111) surface serve to monitor the local electronic perturbation caused by the interaction of the wire end with the step edge, giving information on the quality of the contact.

Journal Article↗
PubMed2003

Myocardial protection of immature rabbits: polarizing versus depolarizing.

BACKGROUND: This study was designed to identify the potassium-channel opener pinacidil as a cardioplegic agent vs hyperkalemic cardioplegia in terms of its efficacy in immature cardioprotection. METHODS: By a Langendorff model, 21 hearts of 21- to 28-day-old New Zealand rabbits underwent 90 min of global hypothermic (15 degrees C) ischemia protected with a different single dose of hypothermic (4 degrees C) cardioplegia (pinacidil [50 micromol/l], St. Thomas' solution combined with pinacidil [50 micromol/l], and St. Thomas' solution). The percent recovery of the cardiac function, creatine kinase release, and cellular ultrastructure were compared. RESULTS: Pinacidil (50 micromol/l) provided significantly the best postreperfused percentage recovery of the function than the other groups; pinacidil cardioplegia showed a significant reduction of creatine kinase release in the coronary flow compared with the other groups; St. Thomas' solution combined with pinacidil showed the highest release. Percentage recovery of the coronary flow, water contents, and ultrastructural changes were similar between the groups. CONCLUSIONS: Pinacidil provided better protection during ischemia-reperfusion in the immature rabbit heart than St. Thomas' solution, whereas pinacidil combined with St. Thomas' solution showed the worst protective effects in immature hearts.

Aging↗
PubMed2003

Mutations in tau gene exon 10 associated with FTDP-17 alter the activity of an exonic splicing enhancer to interact with Tra2 beta.

Mutations in the human tau gene leading to aberrant splicing have been identified in FTDP-17, an autosomal dominant hereditary neurodegenerative disorder. Molecular mechanisms by which such mutations cause tau aberrant splicing were not understood. We characterized two mutations in exon 10 of the tau gene, N279K and Del280K. Our results revealed an exonic splicing enhancer element located in exon 10. The activity of this AG-rich splicing enhancer was altered by N279K and Del280K mutations. This exonic enhancer element interacts with human Tra2 beta protein. The interaction between Tra2 beta and the exonic splicing enhancer correlates with the activity of this enhancer element in stimulating splicing. Biochemical studies including in vitro splicing and RNA interference experiments in transfected cells support a role for Tra2 beta protein in regulating alternative splicing of human tau gene. Our results implicate the human tau gene as a target gene for the alternative splicing regulator Tra2 beta, suggesting that Tra2 beta may play a role in aberrant tau exon 10 alternative splicing and in the pathogenesis of tauopathies.

Alternative Splicing↗
PubMed2003

Changes of attitudes and patronage behaviors in response to a smoke-free bar law.

OBJECTIVES: We examined patron responses to a California smoke-free bar law. METHODS: Three telephone surveys measured attitudes and behavior changes after implementation of the law. RESULTS: Approval of the law rose from 59.8% to 73.2% (odds ratio [OR] = 1.95; 95% confidence interval [CI] = 1.58, 2.40). Self-reported noncompliance decreased from 24.6% to 14.0% (OR = 0.50; 95% CI = 0.30, 0.85). Likelihood of visiting a bar or of not changing bar patronage after the law was implemented increased from 86% to 91% (OR = 1.76; 95% CI = 1.29, 2.40). CONCLUSIONS: California bar patrons increasingly support and comply with the smoke-free bar law.

Adult↗
PubMed2002

Slit proteins, potential endogenous modulators of inflammation.

Recent studies suggest that molecules important for guiding neuronal migration and axon path-finding also play a role in modulating leukocyte chemotaxis. Neuronal migration and leukocyte chemotaxis may share some common regulatory mechanisms. Intracellular signal transduction mechanisms guiding neuronal migration and leukocyte chemotaxis are beginning to be elucidated. Studying molecular mechanisms modulating cell migration may provide new insights into understanding of endogenous inhibitors of inflammation.

Glycoproteins↗
PubMed2002

[Effect of boanmycin on apoptosis and cell cycle of human esophageal cancer(Eca-109) cells].

BACKGROUND & OBJECTIVE: The anticancer mechanism of boanmycin was thought to inhibit the synthesis of protein in human esophageal cancer cell line. But it is not clear that there are other mechanisms of boanmycin to produce its anticancer effect on human esophageal cancer. This study was designed to examine the effect of boanmycin on apoptosis and cell cycle of human esophageal cancer cells (Eca-109). METHODS: Microscopic observation, flow cytometry, and agarose gel electrophoresis were used to determine the induction of apoptosis and the changes of cell cycle. RESULTS: The human esophageal cancer xenografts in nude mice treated by boanmycin showed morphological changes of different apoptotic phases. In vitro, boanmycin (50-125 micrograms/ml, 30-36 hours) elicited typical apoptotic changes in Eca-109 cells and typical DNA ladder of apoptotic cells appeared. The Eca-109 cells treated by boanmycin for 42 hours were blocked at G2/M phase. CONCLUSION: Boanmycin could induce apoptosis of Eca-109 cells and block the cell cycle at G2/M phase.

Animals↗