Avian influenza A (H5N1) infection in a patient in China, 2006

BACKGROUND

Highly pathogenic avian influenza H5N1 virus has caused increasing human infection in Eurasia since 2004. So far, H5N1 human infection has been associated with over 50% mortality that is partly because of delay of diagnosis and treatment.

OBJECTIVES AND METHODS

Here, we report that an H5N1 influenza virus infected a 31-year-old patient in Shenzhen in June 2006. To identify the possible source of the infection, the human isolate and other H5N1 influenza viruses obtained from poultry and wild birds in southern China during the same period of time were characterized.

RESULTS

Genetic and antigenic analyses revealed that the human H5N1 influenza virus, Shenzhen/406H/06, is of purely avian origin and is most closely related to viruses detected in poultry and wild birds in Hong Kong in early 2006.

CONCLUSIONS

The findings of the present study suggest that the continued endemicity of H5N1 influenza virus in the poultry in southern China increases the chance for introduction of the virus to humans. This highlights the importance of continued surveillance of poultry and wild birds for determining the source for human H5N1 infection.

Global Inorganic Source of Atmospheric Bromine

A few bromine molecules per trillion (ppt) causes the complete destruction of ozone in the lower troposphere during polar spring and about half of the losses associated with the "ozone hole" in the stratosphere. Recent field and aerial measurements of the proxy BrO in the free troposphere suggest an even more pervasive global role for bromine. Models, which quantify ozone trends by assuming atmospheric inorganic bromine (Bry) stems exclusively from long-lived bromoalkane gases, significantly underpredict BrO measurements. This discrepancy effectively implies a ubiquitous tropospheric background level of approximately 4 ppt Bry of unknown origin. Here, we report that I- efficiently catalyzes the oxidation of Br- and Cl- in aqueous nanodroplets exposed to ozone, the everpresent atmospheric oxidizer, under conditions resembling those encountered in marine aerosols. Br- and Cl-, which are rather unreactive toward O3 and were previously deemed unlikely direct precursors of atmospheric halogens, are readily converted into IBr2- and ICl2- en route to Br2(g) and Cl2(g) in the presence of I-. Fine sea salt aerosol particles, which are predictably and demonstrably enriched in I- and Br-, are thus expected to globally release photoactive halogen compounds into the atmosphere, even in the absence of sunlight.

The expression of P-gp, Bcl-2 and VEGF in epithelial ovarian carcinoma and their significance

16075

Background: To investigate the expression of P - gp,Bcl-2 and VEGF in epithelial ovarian carcinoma as well as their significance. Methods: Expression of P- gp,Bcl-2 and VEGF were examined in 72 epithelial ovarian carcinoma by immunohistochemisty (method of S - P) . Results: The positive expressions of P - gp,Bcl-2 and VEGF in patients with ovarian carcinoma were 51.4%,54.2%,56.9% respectively .Compared with those in ovarian benign tumors and normal controls, such expression level were significantly higher ( P < 0.05). The expression of P - gp was positively correlated with the expression of VEGF( P <0. 05) while the expression of VEGF was positively correlated with the expression of Bcl-2 ( P <0. 05). Univariate analysis showed worse disease-free survival in the patients with positive expression of P-gp or VEGF than in those with negative expression of P -gp or VEGF( P < 0. 05). Multivariate analysis of clinical and pathological data by Cox-regression method showed that the expression of P - gp or VEGF and co- expression of these three indexes were correlated with poor prognosis. Conclusions: Over-expression of P - gp,Bcl-2 and VEGF is correlated with drug resistance of clinical chemotherapy and survival rate in ovarian cancer . To examine these 3 indexes in ovarian cancer is helpful to evaluate response to clinical chemotherapy as well as to predict the prognosis.

No significant financial relationships to disclose.

The effect of antisense oligodeoxynucleotides targeting Aurora A kinase on cell proliferation and chemosensitivity to paclitaxel in human lung cancer cell line A549

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Background: Aurora kinases representing a family of evolutionarily conserved mitotic serine/threonine kinases have been found elevated in lung andenocarcinoma cell line A549. It is suggested that the overexpression of Aurora A contributes to the carcinogenesis, chromosomal instability (CIN), and de-differentiation of lung cancers. To address its possibility as a therapeutic target for lung cancer, we employed the antisense oligodeoxynucleotide (ASODN) technique to inhibit Aurora A expression and investegate its effect on tumor growth and cell cycle of A549, as well as the chemosensitivity of paclitaxel. Methods: Aurora A ASODN was synthesized and transfected into A549 cells by lipofectAMINE 2000.Aurora A mRNA and protein expression were examined by reverse transcription -polymerase chain reaction (RT-PCR) and Western blot respectively.Cell cycle distribution was observed by flow cytometer.MTT assay was used to evaluate cell inhibition ratio before and after transfection. Results: The proliferation of the A549 cells was inhibited by Aurora A ASODN dose and time dependently. It was also observed that the IC50 of A549 cells after 48 hours’ treatment of ASODN was about 300nmol/L and under such circumstances, the Aurora A mRNA and protein expression significantly decreased (P<0.05), along with the induction of accumulation of cells in S phase and the G2-M transition. Furhermore, cell inhibition ratio of the combination of Aurora A ASODN and paclitaxel was higher significantly than paclitaxel(P<0.05) or Aurora A ASODN alone (P<0.05). Conclusions: Inhibition of Aurora A expression can results in the suppression of cell growth and chemosensitizing activity to paclitaxel in human lung cancer cell line A549.

No significant financial relationships to disclose.

Comparison of transendocardial and retrograde coronary venous intramyocardial catheter delivery systems in healthy and infarcted pigs

We compared two routes for myocardial delivery of therapeutics, transendocardial (TE) delivery with an intramyocardial injection catheter, and retrograde coronary venous (RCV) delivery with a balloon occlusion catheter in the interventricular vein.

METHODS

TE and RCV injection of 15 microM, neutron-activatable microspheres was compared in healthy pigs (Group I, n = 3), pigs with a 1-week-old myocardial infarction (MI; group II, n = 5), and pigs with a 2-weeks-old MI (group III, n = 4). The MI was induced by a 1-hr balloon occlusion in the LAD. Both methods were compared in the same animal using different microspheres. The RCV catheter allowed for continuous measurement of distal pressure and 2.5 x 10(6) microspheres were injected in 10 ml at 300 mmHg above balloon occlusion pressure. The TE injections were targeted to the infarct zone and 2.5 x 10(6) microspheres were distributed over 10 injections of 200 microl.

RESULTS

The retention of microspheres decreased with increase in MI age, but was comparable between devices within the groups. RCV delivery resulted in (14.3 +/- 0.9)% microsphere retention in Group I, (10.3 +/- 0.2)% in Group II, and (6.4 +/- 0.1)% in group III (P < 0.05 versus group I). Microsphere retention after TE was (15.1 +/- 0.7)% in group I, (18.9 +/- 0.6)% in group II, (4.1 +/- 0.1)% in Group III (P < 0.05 versus groups I and II). The RCV catheter delivered primarily to midventricular, antero-septal segments, whereas TE targeted apical areas predominantly.

CONCLUSIONS

Delivery efficacy was comparable between devices in each group however RCV targeted midventricular areas whereas TE targeted apical areas.

Distribution and characteristics of hepatitis B virus genotype C subgenotypes in China

Genetic diversity within the same hepatitis B virus (HBV) genotype indicates the presence of several subgenotypes. We have found that genotype C is the most common in China, and this study aimed to determine the geographical distribution and characteristics of HBV-C subgenotypes in the country. A cohort of 534 patients with chronic HBV genotype C infection, collected across China, was analysed by nucleotide sequencing or polymerase chain reaction-restriction fragment length polymorphism. HBV-C1/Cs (n = 112, 21%) and HBV-C2/Ce (n = 397, 74%) were the most common HBV-C subgenotypes and showed different geographical distribution in China. No significant differences were found between patients infected with HBV-C1 and HBV-C2 when comparing liver function tests, hepatitis B e antigen positive rate and clinical manifestations. We identified two other types of HBV-C provisionally designated as HBV-CD1 and HBV-CD2, which have particular virological features and clustered in one geographic area. These two types of C/D hybrids have emerged through recombination with genotype D and encode serotype ayw2 hepatitis B surface antigen. In conclusion, there are at least four subtypes of HBV genotype C: subgenotypes C1, C2 and two types of C/D recombinants CD1 and CD2 in China, which have a distinct geographic distribution. Whether HBV-C subgenotypes differ in their impact on liver disease progression requires prospective studies.

Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV

The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.

Structural studies and photochromism of mercury(II)-iodo complexes of (arylazo)imidazoles

Neat reaction between HgI2 and 1-methyl-2-(phenylazo)imidazole (Pai-Me) under microwave irradiation has isolated a novel compound whose structure shows intercalated HgI2 in the layers of Pai-Me. They exist independently in interpenetrated arrays. In a solution phase study, the same reaction has synthesized an iodo-bridged azoimidazole-Hg(II) complex, [Hg(RaaiR')(mu-I)(I)]2 (RaaiR' = 1-alkyl-2-(arylazo)imidazole). The structures have been characterized by X-ray diffraction studies. Chloro-bridged Hg(II) complexes of azoimidazoles, [Hg(RaaiR')(mu-Cl)(Cl)]2, are also known. These complexes upon irradiation with UV light show trans-to-cis isomerization. The reverse transformation, cis-to-trans isomerization, is very slow with visible light irradiation. Quantum yields (phi t-->c) of trans-to-cis isomerization are calculated, and the free ligand shows higher phi than their Hg(II) complexes. The cis-to-trans isomerization is a thermally induced process. The activation energy (Ea) of cis-to-trans isomerization is calculated by controlled temperature reaction. The Ea's of free ligands are much higher than that of halo-bridged Hg(II)-azoimidazole complexes. Chloro-bridged Hg(II) complexes show lower Ea's than those of iodo-bridged complexes. DFT calculation has been adopted to rationalize the experimental results.

Scaling properties of hyperon production in Au+Au collisions at square root [sNN]=200 GeV

We present the scaling properties of Lambda, Xi, and Omega in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at sqrt[s_{NN}]=200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of Lambda, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor gamma_{s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, Lambda, and Xi are consistent with each other for 2<p_{T}<5 GeV/c in agreement with a scenario of hadron formation from constituent quark degrees of freedom.

Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at square root of s = 200 GeV

We report a measurement of the longitudinal double-spin asymmetry A(LL) and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at square root of s = 200 GeV. The cross section data cover transverse momenta 5 < pT < 50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A(LL) data cover 5 < pT < 17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.

Evaluation of the CLSI cefoxitin 30-microg disk-diffusion method for detecting methicillin resistance in staphylococci

Methicillin susceptibility of 415 staphylococcal isolates from Chinese hospitals was assessed using the CLSI disk-diffusion method with a cefoxitin 30-microg disk in comparison with an oxacillin 1-microg disk. PCR-based detection of mecA was the reference standard. The cefoxitin 30-microg disk performed with almost the same high level of accuracy as the oxacillin 1-microg disk in detecting methicillin resistance in Staphylococcus aureus. For coagulase-negative staphylococci (CoNS), the sensitivity of the cefoxitin 30-microg disk was 90.5%, compared with 83.4% for the oxacillin 1-microg disk. Confirmatory testing of isolates with borderline susceptibility and revision of the cefoxitin breakpoint are proposed in order to categorise CoNS more accurately.

Selective depletion of activated T cells by recombinant immunotoxin containing anti-CTLA-4 single-chain fragment of variable antibody and N-terminal fragment of perforin

We constructed a novel immunotoxin, hS83P34, by fusing the fragment containing the N-terminal 34 amino acids of human perforin to the C-terminal of humanized anti-CTLA-4 single chain fragment of variable antibody. In vitro cytotoxicity assays demonstrated that CTLA-4-positive activated human T cells and 6T-CEM were sensitive to hS83P34, while CTLA-4-negative resting T cells and endothelial cell ECV-304 were resistant to hS83P34. The IC50s of hS83P34 for activated T cells and 6T-CEM were about 0.2 micromol/L and 1.0 micromol/L, there was no obvious cytotoxicity of ECV-304 as detected at 8 micromol/L of hS83P34. In tumor graft rejection models, after treatment with 1.2 mg/kg immunotoxin every day for 12 days, the transplanted tumor cells were rescued by immunotoxin. The tumor weights of grafts of the rejection control group, nonrejection control group, and test group were 0.006 +/- 0.014 g, 0.261 +/- 0.048 g, and 0.135 +/- 0.056 g, respectively. In the early 3 days posttransplantation, there were a lot of CD4- and CD8-positive T cells infiltrating into the tumor grafts of the rejection control group, while only a few T cells were detected in the tumor grafts of the test group. According to these results, we concluded that immunotoxin hS83P34 selectively depleted activated T cells in vitro as well as in vivo in an acute rejection model.

Direct observation of dijets in central Au+Au collisions at sqrt[sNN]=200 GeV

The STAR Collaboration at the Relativistic Heavy Ion Collider reports measurements of azimuthal correlations of high transverse momentum (pT) charged hadrons in Au+Au collisions at higher pT than reported previously. As (pT) is increased, a narrow, back-to-back peak emerges above the decreasing background, providing a clear dijet signal for all collision centralities studied. Using these correlations, we perform a systematic study of dijet production and suppression in nuclear collisions, providing new constraints on the mechanisms underlying partonic energy loss in dense matter.

Identified baryon and meson distributions at large transverse momenta from Au + Au collisions at square root sNN=200 GeV

Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at square root sNN=200 GeV are presented. In central Au + Au collisions, both pi +/- and p(p) show significant suppression with respect to binary scaling at pT approximately >4 GeV/c. Protons and antiprotons are less suppressed than pi+/-, in the range 1.5 approximately < pT approximately < 6 GeV/c. The pi-/pi+ and p/p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at pT approximately >5 GeV/c. The results at high pT indicate that the partonic sources of pi+/-, p, and p have similar energy loss when traversing the nuclear medium.

Forward neutral pion production in p + p and d + Au collisions at square root sNN=200 GeV

Measurements of the production of forward pi0 mesons from p + p and d + Au collisions at square root sNN=200 GeV are reported. The p + p yield generally agrees with next-to-leading order perturbative QCD calculations. The d + Au yield per binary collision is suppressed as eta increases, decreasing to approximately 30% of the p + p yield at eta =4.00, well below shadowing expectations. Exploratory measurements of azimuthal correlations of the forward pi0 with charged hadrons at eta approximately 0 show a recoil peak in p + p that is suppressed in d + Au at low pion energy. These observations are qualitatively consistent with a saturation picture of the low-x gluon structure of heavy nuclei.

Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions

We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Analysis of candidate genes on chromosome 2 in oral cleft case-parent trios from three populations

Isolated oral clefts, including cleft lip with/without cleft palate (CL/P) and cleft palate (CP), have a complex and heterogeneous etiology. Case-parent trios from three populations were used to study genes spanning chromosome 2, where single nucleotide polymorphic (SNP) markers were analyzed individually and as haplotypes. Case-parent trios from three populations (74 from Maryland, 64 from Singapore and 95 from Taiwan) were genotyped for 962 SNPs in 104 genes on chromosome 2, including two well-recognized candidate genes: TGFA and SATB2. Individual SNPs and haplotypes (in sliding windows of 2-5 SNPs) were used to test for linkage and disequilibrium separately in CL/P and CP trios. A novel candidate gene (ZNF533) showed consistent evidence of linkage and disequilibrium in all three populations for both CL/P and CP. SNPs in key regions of ZNF533 showed considerable variability in estimated genotypic odds ratios and their significance, suggesting allelic heterogeneity. Haplotype frequencies for regions of ZNF533 were estimated and used to partition genetic variance into among-and within-population components. Wright's fixation index, a measure of genetic diversity, showed little difference between Singapore and Taiwan compared with Maryland. The tensin-1 gene (TNS1) also showed evidence of linkage and disequilibrium among both CL/P and CP trios in all three populations, albeit at a lower level of significance. Additional genes (VAX2, GLI2, ZHFX1B on 2p; WNT6-WNT10A and COL4A3-COL4A4 on 2q) showed consistent evidence of linkage and disequilibrium only among CL/P trios in all three populations, and TGFA showed significant evidence in two of three populations.

[Screening and cloning of the down-regulation gene by recombinant interferon-B using suppression subtractive hybridization technique.]

BACKGROUND

To construct a subtractive cDNA library of target genes down-regulated in human hepatocarcinoma cell line HepG2 cells treated with IFNB, and clone genes of the down-regulation by IFNB using suppression subtractive hybridization (SSH) technology and bioinformatics techniques.

METHODS

The mRNA was isolated from HepG2 cells induced by recombinant interferon-B and 0.9 percent sodium chloride, respectively, then cDNA was synthesized. After restriction enzyme Rsa I digestion, small sizes cDNAs were obtained. Then tester cDNA was divided into two portions and each was ligated to the specific cDNA adaptor 1 and adaptor 2 respectively. After tester cDNA was hybridized with driver cDNA twice and underwent two times of nested PCR, the DNA fragment was subcloned into T/A plasmid vectors to set up the subtractive library. Amplification of the library was carried out with E.coli strain DH5a. The cDNA was sequenced and analyzed in GenBank with Blast search after PCR.

RESULTS

The subtractive library of genes down-regulation in HepG2 cells treated with recombination interferon-B was constructed successfully. The amplified library contained 58 positive clones. Colony PCR and sequence analysis was performed in 35 clones randomly, and the full length sequences were obtained with bioinformatics method. Altogether 12 coding sequences were obtained.

CONCLUSION

A subtractive cDNA library of genes down-regulation in HepG2 cells treated with IFNB using SSH technique was constructed successfully, which brings some new clues for studying the regulation mechenism of IFNB in liver cells.