Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.

Association between short sleep duration and the risk of sensitization to food and aero allergens in rural Chinese adolescents

BACKGROUND

Both long and short sleep duration have been associated with obesity, cardiovascular disease, and diabetes. However, there have been no previous studies investigating the potential relationship between altered sleep duration and allergen sensitization.

OBJECTIVE

To explore the association between sleep duration and sensitization to food and aeroallergens.

METHODS

This study includes 1534 rural Chinese adolescent twins aged 12-21 years who completed standard sleep questionnaires and skin prick tests (SPTs) to nine food and five aeroallergens. Total sleep time was defined as the interval from bedtime to wake-up time minus sleep latency. Sensitization was defined as having at least one positive SPT.

RESULTS

Compared with individuals with the highest (third) tertile of sleep duration, those who slept less were more likely to be sensitized to any food allergen with odds ratios (ORs) of 1.9 [95% confidence interval (CI): 1.3-2.7] and 1.4 (95% CI: 1.0-1.9) for the first and second tertiles (trend test P(trend)=3×10(-4)), respectively. The corresponding ORs for sensitization to any aeroallergen were 1.5 (95% CI: 1.1-2.0) and 1.3 (95% CI: 1.0-1.7) (P(trend)=8×10(-3)). These associations were independent of percent body fat. In addition, we observed a significant dose-response association between the number of positive SPTs and percentage of shortest sleep duration (first tertile) (P(trend)=1×10(-3)).

CONCLUSIONS AND CLINICAL RELEVANCE

In this sample of relatively lean rural Chinese adolescents, we found that short sleep duration was associated with increasing risk of sensitization to food and aeroallergens, independent of percent body fat. Longitudinal studies are needed to further determine the temporal and causal relationships. If short sleep duration indeed is one of the risk factors for allergic sensitization, the global burden of allergic diseases could be dramatically reduced by providing appropriate guidance on sleep duration for youth.

134 EFFECTS OF VITAMIN E AND VITAMIN C ON THE DEVELOPMENTAL COMPETENCE OF BUFFALO (BUBALUS BUBALIS) EMBRYOS DERIVED FROM PARTHENOGENETIC ACTIVATION, IN VITRO FERTILIZATION, AND NUCLEAR TRANSFER

The purpose of this study was to explore the effects of vitamin E (VE) and vitamin C (VC) on the in vitro development of embryos derived from parthenogenetic activation (PA), in vitro fertilization (IVF), and somatic cell nuclear transfer (NT) in buffalo (Bubalus bubalis). Buffalo oocytes obtained from ovaries at slaughter were matured in vitro for 22 to 24 h. After maturation, oocytes were separated to 3 groups: one group of oocytes was fertilized in vitro with buffalo sperm; one group of oocytes was parthenogenetically activated by exposing them to 5 μM ionomycin for 5 min and then cultured in 2 mM 6-DMAP for 3 h; the other group of oocytes was enucleated, and fibroblasts in DMEM + 10% FBS for 4 to 5 days were transferred into enucleated oocytes by electronic fusion (100 v mm–1, 15 μs, and 3 pulses). After fusion, the activation of reconstructed embryos was induced by exposure to 5 μM ionomycin for 5 min and then cultured in 2 mM 6-DMAP for 3 h. The embryos of PA, IVF, and NT were respectively cultured in the culture medium (CM) containing different concentrations of VE, VC, or VE + VC for 7 to 9 days to evaluate embryonic development. As a result, when the embryos were cultured in the CM with different concentrations of VE (0, 50, 100, 150, and 200 μM), the blastocyst development rate of the embryos derived from PA, IVF, and NT gradually rose with increasing concentrations of VE and reached the highest amount [PA: 32.9% (81/246); IVF: 21.4% (45/210); and NT: 21.1% (47/223)] in the group containing 150 μM of VE; it was significantly higher than that of other groups (P < 0.05). When the different concentrations of VC (0, 50, 100, 150, and 200 μM) were added to the CM, the blastocyst development rate of the embryos derived from PA, IVF, and NT also enhanced according to the increasing concentration of VC, and more embryos developed to blastocysts in the group containing 150 μM of VC [PA: 31.2% (72/231); IVF: 20.2% (43/213); NT: 19.8% (48/243)] than in the other groups (P < 0.05). Compared with the control group (0 μM), the blastocyst rate of PA and IVF, as well as NT embryos, cultured in the CM with 150 μM VE + 150 μM VC groups was significantly higher (P < 0.05), but there were no significant differences in the percentage of blastocysts among groups of the 150 μM VE, 150 μM VC, and 150 μM VE + 150 μM VC (P > 0.05). These results indicated that adding VE (150 μM), VC (150 μM), or VE (150 μM) + VC (150 μM) in the CM could efficiently enhance the developmental competence of buffalo embryos during in vitro culture. This work was funded by China High Technology Development Program (2007AA100505), Guangxi Science Foundation (0718005-3A), Fok Ying Tung Education Foundation (111034).

Knocking out of tailoring genes eryK and eryG in an industrial erythromycin-producing strain of Saccharopolyspora erythraea leading to overproduction of erythromycin B, C and D at different conversion ratios

AIMS

 To overproduce erythromycin C, B or D and evaluate the effect of disruption of tailoring genes eryK and eryG in an industrial erythromycin producer.

METHODS AND RESULTS

  The tailoring genes eryG and eryK were inactivated individually or simultaneously by targeted gene disruption in an industrial strain Saccharopolyspora erythraea HL3168 E3, resulting in the overproduction of erythromycin C (2·48 g l(-1) ), B (1·70 g l(-1) ) or D (2·15 g l(-1) ) in the mutant strain QL-G, QL-K or QL-KG, respectively. Analysis of the erythromycin congeners throughout the fermentation indicated that, at the end of fermentation, comparatively large amount of erythromycin D (0·67 g l(-1) ) was accumulated in QL-G, whereas only small amount of erythromycin D (0·10 g l(-1) ) was produced in QL-K.

CONCLUSIONS

Inactivation of tailoring genes eryG and eryK in the high producer did not affect the biosynthesis of erythromycin. However, erythromycin D could be more efficiently methylated by EryG than be hydroxylated by EryK.

SIGNIFICANCE AND IMPACT OF THE STUDY

Development of the mutant strains provides a method for the economical large-scale production of potent lead compounds. The information about the accumulation and conversion of erythromycins in the industrial strains may contribute to further improving erythromycin production.

Abstract PD02-09: Effects of an mTOR Inhibitor RAD001 on Human Breast Cancer Stem Cells In Vitro

Background: Recent evidences have suggested that there are a rare population of cells called cancer stem cells (CSCs) in breast cancer, which have the ability of extensive self-renewal and contribute to metastasis and treatment resistance. This study evaluated the effects of an mTOR inhibitor, RAD001 (Everolimus) on breast CSCs of primary breast cancer cells and 2 breast cancer cell lines (MCF-7, MDA-MB-231) in vitro. Methods: Primarily, we isolated primary breast cancer cells from the 1cm3 axenic tissue from breast cancer patients, which was been digested in collagenase typelV in 1-3 hours. After filtration, the cells from the organoid were plated in DMEM/F12(1:1) containing 10% FBS ,100U/ml penicillin,100µg/ml streptomycin and some growth factors overnight. The next day, we sorted CD44 +, CD24-/low, ESA + cells as breast CSCs by flow cytometry from primary breast cancer cells, breast cancer cell lines MCF-7 and MDA-MB-231. And then the three CSCs were treated with different concentrations of docetaxel alone(0,20µM,40µM,80µM, 160µM), mTOR inhibitor RAD001 alone (0,10nM,100nM,1µM,10µM), or in combination with docetaxel(20µM).the Inhibition of the drugs on different Breast CSCs was quantified by methyl thiazolyl tetrazolium (MTT) assay. All employed CSCs were divided into four groups, given respectively 24h treatment of RAD001(100nM), docetaxel(20µM), combination or contrals. Apoptosis and distribution of cell cycles were examined with flow cytometry. Experiments were performed in triplicate. Result: All three kinds of breast CSCs were resistant to the standard treatment doses of docetaxel in vitro(IC50=80 µM±5µM),compared with this drug inhibited normal breast cancer cell lines(IC50=16µM±2µM). Treatment with RAD001 resulted in growth inhibition of all employed CSCs in a dose-dependent manner, which is more effective than the treatment with docetaxel alone(P&lt;0.001), and CSCs of MDA-MB-231 proved to be most sensitive to this drug(IC20=8nM).Combination studies showed that there was an additive growth inhibitory effect of a combination treatment on three CSCs in vitro compared with treatment with RAD001 alone (P&lt;0.001)or docetaxel alone(P&lt;0.001). In addition, an increase in G2-M cell cycle arrest were seen in the combination treatment group when compared with controls(P&lt;0.05), suggesting that cell cycle arrest may contribute to the increased growth inhibitory effects of combination treatment seen in this study. In primary CSCs, combined treatment induced a mount-up population of early apoptosis, the phenomenon was not taken place in the treatment of RAD001 alone, however, it's no statistical significance(P&gt;0.05).

Discussion: We conclude that RAD001 has more effective inhibitory effect than docetaxel, and enhances the cytotoxic effects of docetaxel in models of breast CSCs in vitro by inducing cell cycle arrest, indicating that combination treatment with RAD001 and docetaxel may be an efficient therapy for refractory and metastatic breast cancer. But the drug interaction of RAD001 and docetaxel in the clinical situation has to be evaluated in further studies.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD02-09.

A novel approach for the simultaneous determination of iodide, iodate and organo-iodide for 127I and 129I in environmental samples using gas chromatography-mass spectrometry

In aquatic environments, iodine mainly exists as iodide, iodate, and organic iodine. The high mobility of iodine in aquatic systems has led to (129)I contamination problems at sites where nuclear fuel has been reprocessed, such as the F-area of Savannah River Site. In order to assess the distribution of (129)I and stable (127)I in environmental systems, a sensitive and rapid method was developed which enables determination of isotopic ratios of speciated iodine. Iodide concentrations were quantified using gas chromatography-mass spectrometry (GC-MS) after derivatization to 4-iodo-N,N-dimethylaniline. Iodate concentrations were quantified by measuring the difference of iodide concentrations in the solution before and after reduction by Na(2)S(2)O(5). Total iodine, including inorganic and organic iodine, was determined after conversion to iodate by combustion at 900 °C. Organo-iodine was calculated as the difference between the total iodine and total inorganic iodine (iodide and iodate). The detection limits of iodide-127 and iodate-127 were 0.34 nM and 1.11 nM, respectively, whereas the detection limits for both iodide-129 and iodate-129 was 0.08 nM (i.e., 2pCi (129)I/L). This method was successfully applied to water samples from the contaminated Savannah River Site, South Carolina, and more pristine Galveston Bay, Texas.

One-dimensional single-crystalline bismuth oxide micro/nanoribbons: morphology-controlled synthesis and luminescent properties

Based on a facile vapor-phase transport method without any catalyst and template, one-dimensional single-crystalline bismuth oxide (Bi2O3) micro/nanoribbons were fabricated on silicon substrates in large quantities and morphology-controlled fabrication of Bi2O3 was achieved from a single precursor. The widths of Bi2O3 ribbons varied from 0.2 to 20 microm depending on the deposition temperatures. The thickness was in the range of 0.1-2 microm and the length reached several hundred micrometers and even millimeter range. The detailed composition and structural analysis confirmed the single-crystalline nature of alpha-Bi2O3 micro/nanoribbons with monoclinic structure. The photoluminescence spectrum of a single Bi2O3 ribbon showed a broadband emission from 450 to 750 nm in the visible region, consisting two peaks located at 589 and 697 nm which were primarily originated from the impurity ions and crystal defects. A self-catalyzed vapor-solid model was proposed to account for the growth mechanism of Bi2O3 ribbons with different morphologies.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.