Measurement of the neutron radius of 208Pb through parity violation in electron scattering

We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

New precision limit on the strange vector form factors of the proton

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7 GeV{2}

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7  GeV{2}. The corresponding neutron A{LT} asymmetries were extracted from the measured {3}He asymmetries and proton over {3}He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g{1T}{q} and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π{-} production on {3}He and the neutron, while our π{+} asymmetries are consistent with zero.

Worldwide genetic structure in 37 genes important in telomere biology

Telomeres form the ends of eukaryotic chromosomes and are vital in maintaining genetic integrity. Telomere dysfunction is associated with cancer and several chronic diseases. Patterns of genetic variation across individuals can provide keys to further understanding the evolutionary history of genes. We investigated patterns of differentiation and population structure of 37 telomere maintenance genes among 53 worldwide populations. Data from 898 unrelated individuals were obtained from the genome-wide scan of the Human Genome Diversity Panel (HGDP) and from 270 unrelated individuals from the International HapMap Project at 716 single-nucleotide polymorphism (SNP) loci. We additionally compared this gene set to HGDP data at 1396 SNPs in 174 innate immunity genes. The majority of the telomere biology genes had low to moderate haplotype diversity (45-85%), high ancestral allele frequencies (>60%) and low differentiation (FST<0.10). Heterozygosity and differentiation were significantly lower in telomere biology genes compared with the innate immunity genes. There was evidence of evolutionary selection in ACD, TERF2IP, NOLA2, POT1 and TNKS in this data set, which was consistent in HapMap 3. TERT had higher than expected levels of haplotype diversity, likely attributable to a lack of linkage disequilibrium, and a potential cancer-associated SNP in this gene, rs2736100, varied substantially in genotype frequency across major continental regions. It is possible that the genes under selection could influence telomere biology diseases. As a group, there appears to be less diversity and differentiation in telomere biology genes than in genes with different functions, possibly due to their critical role in telomere maintenance and chromosomal stability.

Moxifloxacin monotherapy for treatment of complicated intra-abdominal infections: a meta-analysis of randomised controlled trials

To evaluate the efficacy and safety of moxifloxacin monotherapy for treatment of complicated intra-abdominal infections. PubMed, EMBASE, Science Direct, ClinicalTrials.gov and Cochrane Central Register of Controlled Trials were searched to retrieve randomised controlled trials (RCTs) compared moxifloxacin monotherapy with other antibiotics in the treatment of complicated intra-abdominal infections from January 1999 to July 2011. A meta-analysis of all included randomised controlled trials was performed. Four randomised controlled trials including a total of 2444 patients with complicated intra-abdominal infections were included for meta-analysis. The results of the meta-analysis indicated that the moxifloxacin was associated with similar clinical cure rate (four RCTs, 1934 patients, OR = 0.80, 95% CI: 0.61, 1.04, p = 0.09), bacteriological success rates (four RCTs, 1484 patients, OR = 0.79, 95% CI: 0.59, 1.05, p = 0.11) and mortality (four RCTs, 2227 patients, OR = 0.91, 95% CI: 0.45, 1.83, p = 0.79) compared with the control group. The overall incidence of adverse events of moxifloxacin was significantly higher than that in the control group (three RCTs, 1367 patients, OR = 1.33, 95% CI: 1.07, 1.63, p = 0.008), although the incidence of drug-related adverse events (three RCTs, 1601 patients, OR = 1.13, 95% CI: 0.69, 1.85, p = 0.63) and serious adverse events (three RCTs, 1815 patients, OR = 1.23, 95% CI: 0.59, 2.60, p = 0.58) were similar between the compared treatment groups. Moxifloxacin is an effective and relatively safe option for the treatment of patients with intra-abdominal infections. Moxifloxacin monotherapy has similar efficacy to combination therapy.

P3-16-02: Targeting Tumor Initiating Cells with siRNA/Nanotherapy in Triple Negative Breast Cancer

Residual human breast tumor cells after conventional therapies are enriched in tumor-initiating cells (TIC) characterized by CD44+/ CD24-/low/lineage- with self-renewal capacities. Our gene expression analyses in those cells and in breast cancer cells propagated as mammospheres (MSs) reveal an epithelial-mesenchymal-transition (EMT) signature (400 genes) mainly found in claudin-low molecular subtype human breast tumors. We performed lentiviral shRNA knockdown of that signature in MS. Critical shRNAs were found to decrease the TIC subpopulation. Among those genes, we found STAT3 (signal transducer and activator of transcription 3), NTN4 (netrin 4), and RPL39L (ribosomal protein L39-like). Here, we used a multiscale siRNA delivery system targeting those three genes in order to clarify the effect of silencing those genes over the self-renewal capacity on MSs with claudin-low features. To this end, duplex small interfering RNA (siRNA) against STAT3, NTN4, RPL39L, and scrambled siRNA as control, were introduced into neutral nanoliposomes (dioleoyl phosphatidylcholine, DOPC), and using mesoporous microscale biodegradable silicon particles as carriers. This multistage siRNA delivery system has been reported as a good approach for sustained gene silencing. Claudin-low-like human breast cancer cell lines (SUM159 and BT549) were plated in 24-well ultralow attachment plates with mammary epithelial growth medium (MEGM) (5,000 cells/well). Both cell lines were then treated with 1μg/well/6 wells of silicon particles loaded with DOPC nanoliposomes/siRNA. The primary MSs were allowed to grow for 3 days. MFs were counted by day 3 with a GelCount colony counter (Oxford Optronix, Oxford, UK). Mammosphere-Forming Efficiency (MSFE) was calculated by dividing the number of MSs by the number of seeded cells. In addition, established MSs were serially passaged by dissociation, and single cells were replated on fresh 24-well ultra-low attachment plates to form secondary mammospheres, which were counted after 3 days. One-way ANOVA and Tukey test were performed. A p value less than 0.05 was considered as significant. Our results show that silencing STAT3, NTN4, and RPL39L significantly reduces the MSFE in both primary (1%, 0.9%, and 1.7% respectively) (Figure 1) and secondary MSs (0.49%, 0.51%, and 0.45% respectively) (Figure 2) when compared to the scrambled control (2.4% and 1 % respectively) in BT549 cells. For SUM159 cells, we did not find any change in primary MSs for STAT3 (2.2%) and NTN4 (2.1%), even we found a higher percentage of MSFE in those cells treated with RPL39L siRNA (3.9%) when compared to the scrambled control (2.1%) (Figure 3). Nevertheless, a lesser MSFE were observed in those cells treated with STAT3 (0.9%, not significant), NTN4 (0.8%) and RPL39L (0.78%) in comparison to control (1.1%) (Figure 4). In conclusion, knocking-down of EMT-related genes (STAT3, NTN4, and RPL39L) decreases significantly the self-renewal capacity in mammospheres derived from claudin-low-like human breast tumor cells, being BT549 cells more sensitive than SUM159 cells to that silencing with siRNA loaded in DOPC nanoliposomes into silicon particles as carriers.

Acknowledgments: We thank Fundacion Alfonso Martin Escudero for the personal support of Dr. Sergio Granados-Principal.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-16-02.

Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

AFOMP Policy Statement No. 3: recommendations for the education and training of medical physicists in AFOMP countries

AFOMP recognizes that clinical medical physicists should demonstrate that they are competent to practice their profession by obtaining appropriate education, training and supervised experience in the specialties of medical physics in which they practice, as well as having a basic knowledge of other specialties. To help its member countries to achieve this, AFOMP has developed this policy to provide guidance when developing medical physicist education and training programs. The policy is compatible with the standards being promoted by the International Organization for Medical Physics and the International Medical Physics Certification Board.

Impact of luteolin on the production of alpha-toxin by Staphylococcus aureus

AIMS

To investigate the influence of subinhibitory concentrations of luteolin on the production of α-toxin in Staphylococcus aureus.

METHODS AND RESULTS

The minimal inhibitory concentrations (MICs) were determined using a broth microdilution method, and the MICs of luteolin against the tested Staph. aureus strains ranged from 16 to 64 μg ml(-1). Haemolysis, Western blot and real-time reverse transcription (RT)-PCR assays were used to evaluate the effect of luteolin on Staph. aureusα-toxin secretion and on the level of gene expression, respectively. The data indicated that subinhibitory concentrations of luteolin dose dependently decreased the production of α-toxin in both meticillin-sensitive Staph. aureus (MSSA) and meticillin-resistant Staph. aureus (MRSA). Furthermore, the transcriptional levels of agr (accessory gene regulator) in Staph. aureus were also inhibited by luteolin.

CONCLUSIONS

Luteolin decreases the production and/or secretion of α-toxin in Staph. aureus; the reduced production may be dependent, in part, upon the luteolin-induced inhibition of the agr locus.

SIGNIFICANCE AND IMPACT OF THE STUDY

The findings indicate that luteolin may be used as a basis for the development of antimicrobial agents aimed at bacterial virulence factors.

A polymorphism of the GTP-cyclohydrolase I feedback regulator gene alters transcriptional activity and may affect response to SSRI antidepressants

Tetrahydrobiopterin (BH(4)) is an essential cofactor for synthesis of many neurotransmitters including serotonin. In serotonergic neurons, BH(4) is tightly regulated by GTP-cyclohydrolase I feedback regulator (GFRP). Given the pivotal role of the serotonergic system in mood disorders and selective serotonin reuptake inhibitors (SSRIs) antidepressant function, we tested the hypothesis that GFRP gene (GCHFR) variants would modify response to antidepressants in subjects with major depression. Two single nucleotide polymorphisms (rs7164342 and rs7163862) in the GCHFR promoter were identified and occurred as two haplotypes (GA or TT). A multiple regression analysis revealed that homozygous individuals for the TT haplotype were less likely to respond to the SSRI fluoxetine than to the tricyclic antidepressant nortriptyline (P = 0.037). Moreover, the TT haplotype showed a reduced transcription rate in luciferase reporter gene assays, which may impact on BH(4)-mediated neurotransmitter production, thus suggesting a biological process through which GCHFR promoter variants might influence antidepressant response.

Influence of proline-rich inositol polyphosphate 5-phosphatase, on early development of fertilized mouse eggs, via inhibition of phosphorylation of Akt

OBJECTIVES

Proline-rich inositol polyphosphate 5-phosphatase (PIPP) is one of the signal-modifying enzymes that play pivotal regulatory roles in PI3K signalling pathway. The aim of this study was to determine the role of PIPP in early development of fertilized mouse eggs, via inhibition of Akt activity and subsequent downstream signalling events.

MATERIALS AND METHODS

The mRNA transcript levels of endogenous PIPP and Akt1, Akt2, Akt3 were detected in G(1) , S, G(2) and M phases of fertilized mouse eggs by RT-PCR. Levels of exogenous PIPP, phosphorylated Akt at Ser473, dephosphorylated cdc2 at Tyr15 and levels of CCNB1, were detected respectively by immunoblotting. Changes in Akt localization were observed by fluoroimmunoassay; meanwhile, changes in activity of Akt and its downstream MPF were detected. Percentages of cells undergoing division were determined by counting, using a dissecting microscope.

RESULTS

PIPP and Akt1 transcripts were detectable in G(1), S, G(2) and M phases of fertilized mouse eggs, but Akt2 and Akt3 were not. We also observed that overexpression of PIPP in fertilized eggs decreased expression of phosphorylated Akt at Ser473 and altered membrane localization of phosphorylated Akt at Ser473 specifically. Furthermore, overexpression of PIPP resulted in decreases in mitosis-phase promoting factor activity, level of dephosphorylated cdc2 at Tyr15 and cleavage rate of fertilized mouse eggs.

CONCLUSIONS

Our data suggest, for the first time, that PIPP may affect development of fertilized mouse eggs by inhibition of level of phosphorylated Akt at Ser473 and subsequent inhibition of downstream signal cascades.

FZD7 has a critical role in cell proliferation in triple negative breast cancer

Breast cancer is genetically and clinically heterogeneous. Triple negative breast cancer (TNBC) is a subtype of breast cancer that is usually associated with poor outcome and lack of benefit from targeted therapy. We used microarray analysis to perform a pathway analysis of TNBC compared with non-triple negative breast cancer (non-TNBC). Overexpression of several Wnt pathway genes, such as frizzled homolog 7 (FZD7), low density lipoprotein receptor-related protein 6 and transcription factor 7 (TCF7) was observed in TNBC, and we directed our focus to the Wnt pathway receptor, FZD7. To validate the function of FZD7, FZD7shRNA was used to knock down FZD7 expression. Notably, reduced cell proliferation and suppressed invasiveness and colony formation were observed in TNBC MDA-MB-231 and BT-20 cells. Study of the possible mechanism indicated that these effects occurred through silencing of the canonical Wnt signaling pathway, as evidenced by loss of nuclear accumulation of β-catenin and decreased transcriptional activity of TCF7. In vivo studies revealed that FZD7shRNA significantly suppressed tumor formation, through reduced cell proliferation, in mice bearing xenografts without FZD7 expression. Our findings suggest that FZD7-involved canonical Wnt signaling pathway is essential for tumorigenesis of TNBC, and thus, FZD7 shows promise as a biomarker and a potential therapeutic target for TNBC.

Preparation of Microcrystalline Silicon Based Solar Cells at High i-layer Deposition Rates Using a Gas Jet Technique

A Gas Jet technique has been used to prepare microcrystalline silicon (μc-Si) thin films at deposition rates as high as 20 Å/s. The films have microcrystal sizes between 80 and 120 Å with a heterogeneous microstructure containing regions with columnar growth and other regions with a more randomly oriented microstructure. These materials have been used as i-layers for nip single-junction solar cells. The high deposition rates allow for fabrication of the required thicker μc-Si i-layers in a similar amount of time to those used for high quality a-SiGe:H i-layers (rates of 1-3 Å/s). Using a 610nm cutoff filter which only allows red light to strike the device, pre-light soaked short circuit currents of 8-10 mA/cm2 and 2.7% red-light efficiencies have been obtained while AM1.5 white light efficiencies are above 7%. These efficiencies are higher than those typically obtained for μc-Si cells prepared at the high i-layer growth rates using other deposition techniques. After 1000 h. of light soaking, the efficiencies on average degrade only by 2-5% (stabilized efficiencies of 2.6%) consistent with the expected high stability with the microcrystalline materials. The small amount of degradation compares with the 15-17% degradation in efficiencies for a-SiGe:H cells subjected to similar irradiation treatments (final light-soaked red light efficiencies of 3.2%). Improvements in the cell efficiencies may come through an understanding of the role that columnar microstructure and void structure plays in determining the device performance.

Amorphous Silicon Alloy Photovoltaic Technology - from R&D to Production

The key requirements for photovoltaic modules to be accepted for large-scale terrestrial applications are (i) low material cost, (ii) high efficiency with good stability, (iii) low manufacturing cost with good yield and (iv) environmental safety. Thin films of amorphous silicon alloy are inexpensive; the products are also environmentally benign. The challenge has been to improve the stable efficiency of these modules and transfer the R&D results into production. Using a Multijunction, Multi-bandgap approach to capture the solar spectrum more efficiently, we have developed one-square-foot modules with initial efficiency of 11.8%. After 1000 h of one-sun light soaking, a stable efficiency of 10.2% was obtained. Both the efficiency values were confirmed by National Renewable Energy Laboratory. The technology has been transferred to production using an automated roll-to-roll process in which different layers of the cell structure are deposited in a continuous manner onto stainless steel rolls, 14” wide and half a mile long. The rolls are next processed into modules of different sizes. This inexpensive manufacturing process produces high efficiency modules with subcell yields greater than 99%. The key features of the technology transfer and future scope for improvement are discussed.

The effects of subinhibitory concentrations of costus oil on virulence factor production in Staphylococcus aureus

AIM

To determine the antimicrobial activity of costus (Saussurea lappa) oil against Staphylococcus aureus, and to evaluate the influence of subinhibitory concentrations of costus oil on virulence-related exoprotein production in staph. aureus.

METHODS AND RESULTS

Minimal inhibitory concentrations (MICs) were determined using a broth microdilution method, and the MICs of costus oil against 32 Staph. aureus strains ranged from 0.15 to 0.6 μl ml(-1) . The MIC(50) and MIC(90) were 0.3 and 0.6 μl ml(-1) , respectively. Western blot, haemolytic, tumour necrosis factor (TNF) release and real-time RT-PCR assays were performed to evaluate the effects of subinhibitory concentrations of costus oil on virulence-associated exoprotein production in Staph. aureus. The data presented here show that costus oil dose dependently decreased the production of α-toxin, toxic shock syndrome toxin 1 (TSST-1) and enterotoxins A and B in both methicillin-sensitive Staph. aureus (MSSA) and methicillin-resistant Staph. aureus (MRSA).

CONCLUSION

Costus oil has potent antimicrobial activity against Staph. aureus, and the production of α-toxin, TSST-1 and enterotoxins A and B in Staph. aureus was decreased by costus oil.

SIGNIFICANCE AND IMPACT OF THE STUDY

The data suggest that costus oil may deserve further investigation for its potential therapeutic value in treating Staph. aureus infections. Furthermore, costus oil could be rationally applied in food products as a novel food preservative both to inhibit the growth of Staph. aureus and to repress the production of exotoxins, particularly staphylococcal enterotoxins.

A rare case of Gerbode defect associated with double orifice mitral valve

Gerbode defect is an unusual cardiac defect; its association with a double orifice mitral valve has not been previously reported. We present a case of a 45-year-old woman who complained of palpitation and dyspnea on exertion. Echocardiography revealed an abnormal communication between the left ventricle and the right atrium, but misinterpreted a double orifice mitral valve as fusion of the anterolateral commissure. The Gerbode defect was closed during cardiopulmonary bypass, while the double orifice mitral valve was left untouched. The patient was discharged 16 days postoperatively.