Dark matter results from 100 live days of XENON100 data

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.

Polymorphism G861C of 5-HT receptor subtype 1B is associated with heroin dependence in Han Chinese

The serotoninergic (5-HT) system regulates neuronal activity in broad brain regions, and appears to be particularly important for modulating behavioral and physiological functions such as mood, emotion, sleep and appetite. Central 5-HT deregulation may be involved in many neuropsychological disorders, which include substance abuse and addiction. Previous studies suggest that genetic polymorphisms in some 5-HT receptor genes may relate to heroin dependency. Here we examined potential association between heroin dependence and four single nucleotide polymorphisms (SNPs) of 5-HT receptors (A-1438G and T102C of HTR(2A), and G861C and A1180G of HTR(1B)) in a cohort of Han Chinese. Participants included 303 heroin-dependent subjects who were recruited into the Methadone Maintenance Treatment (MMT) Program in the Xi'an Mental Health Center, and 300 healthy controls. The resulting data yielded a significantly higher frequency of the HTR(1B) G allele with G861C among the heroin-dependent subjects relative to controls (p=0.001 after Bonferroni correction). Further genotype and clinical phenotype correlation study of the G861C carriers showed that the amount of heroin self-injection was higher in patients with the GG genotype relative to CC and CG genotypes (p<0.01). These findings point to a role for HTR(1B) polymorphism in heroin dependence among Han Chinese, and may be informative for future genetic or neurobiological studies on heroin dependence.

Oral uracil-tegafur plus leucovorin vs fluorouracil bolus plus leucovorin for advanced colorectal cancer: a meta-analysis of five randomized controlled trials

AIM

The aim of this study was to evaluate systematically the efficacy and safety of oral uracil-tegafur (UFT) plus leucovorin (LV) compared with infusional fluorouracil (5-FU) plus LV for advanced colorectal cancer.

METHOD

Eligible studies were identified from Medline, Embase and the Cochrane Library. The end-points included overall survival and overall tumour response rate, and toxicity including leucopenia, febrile neutropenia, stomatitis/mucositis and diarrhoea.

RESULTS

Five randomized controlled trials were identified. Pooled data demonstrated no difference in overall survival between the oral UFT plus LV regimen and the 5-FU bolus plus LV regimen [hazard ratio 1.013; 95% confidence interval (CI) 0.911-1.127].The fixed-effect pooled estimate for overall tumour response rate showed no significant difference between the two regimens (relative risk 0.893; 0.672-1.187). Grade 3-4 leucopenia [odds ratio (OR) 0.126; 955 CI 0.048-0.326], grade 1-4 leucopenia (OR 0.089; 95% CI 0.067-0.119) and grade1-4 febrile neutropenia (OR 0.020; 95% CI 0.004-0.102) were significantly less prominent in the oral UFT regimens. For nonhaematological toxicities, grade 3-4 stomatitis/mucositis (OR 0.075; 95% CI 0.039-0.146), grade 3-4 infection (OR 0.484; 95% CI 0.310-0.758), grade 1-4 infection (OR 0.672; 95% CI 0.547-0.826, P < 0.001), grade 1-4 diarrhoea (OR 0.743; 95% CI 0.626-0.881) were also less likely to happen in patients in the oral UFT plus LV regimen, while there was no significant difference between the two treatment regimens with respect to grade 1-4 stomatitis/mucositis (OR 0.278; 95% CI 0.053-1.456) and grade 3-4 (OR 1.174; 95% CI 0.983-1.403) diarrhoea.

CONCLUSION

Oral UFT or 5-FU bolus combined with LV results in similar overall survival and tumour response rates for advanced colorectal cancer. The former treatment regimen is greatly superior in terms of toxicity, especially haematological toxicity.

The tumor-suppressor gene ARHI (DIRAS3) suppresses ovarian cancer cell migration through inhibition of the Stat3 and FAK/Rho signaling pathways

Ovarian cancers migrate and metastasize over the surface of the peritoneal cavity. Consequently, dysregulation of mechanisms that limit cell migration may be particularly important in the pathogenesis of the disease. ARHI is an imprinted tumor-suppressor gene that is downregulated in >60% of ovarian cancers, and its loss is associated with decreased progression-free survival. ARHI encodes a 26-kDa GTPase with homology to Ras. In contrast to Ras, ARHI inhibits cell growth, but whether it also regulates cell motility has not been studied previously. Here we report that re-expression of ARHI decreases the motility of IL-6- and epidermal growth factor (EGF)-stimulated SKOv3 and Hey ovarian cancer cells, inhibiting both chemotaxis and haptotaxis. ARHI binds to and sequesters Stat3 in the cytoplasm, preventing its translocation to the nucleus and localization in focal adhesion complexes. Stat3 siRNA or the JAK2 inhibitor AG490 produced similar inhibition of motility. However, the combination of ARHI expression with Stat3 knockdown or inhibition produced greatest inhibition in ovarian cancer cell migration, consistent with Stat3-dependent and Stat3-independent mechanisms. Consistent with two distinct signaling pathways, knockdown of Stat3 selectively inhibited IL-6-stimulated migration, whereas knockdown of focal adhesion kinase (FAK) preferentially inhibited EGF-stimulated migration. In EGF-stimulated ovarian cancer cells, re-expression of ARHI inhibited FAK(Y397) and Src(Y416) phosphorylation, disrupted focal adhesions, and blocked FAK-mediated RhoA signaling, resulting in decreased levels of GTP-RhoA. Re-expression of ARHI also disrupted the formation of actin stress fibers in a FAK- and RhoA-dependent manner. Thus, ARHI has a critical and previously uncharacterized role in the regulation of ovarian cancer cell migration, exerting inhibitory effects on two distinct signaling pathways.

A meta-analysis of randomized controlled trials comparing antibacterial therapy with placebo in Crohn's disease

BACKGROUND

Antibacterial therapy has been investigated in several randomized, clinical trials compared with placebo for the management of Crohn's disease. Evidences for the efficacy of intervention are increasingly required.

OBJECTIVES

To conduct a meta-analysis of randomized trials to compare the effects of antibacterial therapy versus placebo in patients with Crohn's disease.

SEARCH STRATEGY

A systematic literature search of Pubmed, EMBASE, Cochrane Library (April 1966 to July 2009) was conducted using specific search terms.

SELECTION CRITERIA

Eligible studies were randomized controlled trials comparing antibacterial (antimycobacterial and broad-spectrum antibiotic) therapy with placebo.

DATA COLLECTION AND ANALYSIS

Studies were reviewed to determine the number of participants, mean follow-up, and the odds ratios (OR) for primary end point of clinical remission and clinical response were also abstracted. The meta-analysis was performed using a fixed-effects model or a randomized-effects model according to the degree of heterogeneity.

RESULTS

Eleven randomized placebo-controlled clinical trials with 668 participants (364 patients in the treatment group and, 304 patients in the placebo group) were identified. Antimycobacterial agents were used in four of the trials and broad-spectrum antibiotics were used in the other seven trials. Pooled analysis showed no significant differences in the rates of clinical remission [OR = 1.28, 95% confidence interval (CI): 0.87-1.90, P = 0.214] and clinical response (OR = 1.52, 95% CI: 0.91-2.55, P = 0.108) after receiving antibacterial treatment for 3 months or longer.

CONCLUSION

In this meta-analysis, no evidence of benefit for antibiotics in patients with Crohn's disease was found.

Does the prophylactic administration of magnesium sulphate to patients undergoing thoracotomy prevent postoperative supraventricular arrhythmias? A randomized controlled trial

BACKGROUND

Supraventricular arrhythmias (SVA) are common after thoracic surgery and are associated with increased morbidity and mortality. This prospective, randomized, double-blind, placebo-controlled trial examined the effects of perioperative magnesium on the development of postoperative SVA.

METHODS

Two hundred patients undergoing thoracotomy for lobectomy, bi-lobectomy, pneumonectomy, or oesophagectomy were recruited and randomly allocated into two groups. The treatment group received magnesium (5 g daily) intraoperatively, and on days 1 and 2 after operation, the control group received placebo. The primary outcome of the study was the development of SVA within the first 5 days after operation.

RESULTS

There were 100 patients in each arm of the study, with one withdrawal and three lost to follow-up in the treatment group and four withdrawals in the control group. Ninety-six patients received magnesium and 96 received placebo. There was no difference in the incidence of SVA between the treatment and control groups, 16.7% (16/96) vs 25% (24/96), P=0.16. In the predefined subgroup analysis, patients at highest risk of arrhythmias (those undergoing pneumonectomy) had a significant reduction in the frequency of SVA, 11.1% (2/18) vs 52.9% (9/17), P=0.008. There were no differences in hospital length of stay or mortality. Patients receiving i.v. magnesium experienced a higher frequency of minor side-effects (stinging at injection site). The treatment was otherwise well tolerated.

CONCLUSIONS

Overall, prophylactic magnesium did not reduce the incidence of SVA in patients undergoing thoracotomy. However, it reduced the incidence of SVA in the high-risk cohort of patients undergoing pneumonectomy. (ISRCTN22028180.).

Immunolocalization of aquaporins in rat brain

The aquaporins (AQPs) are a family of homologous water channels expressed in many tissues. In this study, the expression and immunolocalization of different AQP subtypes in rat brains were investigated by RT-PCR, immunohistochemistry and immunofluorescence. The data showed that AQP1 was expressed in the subpial processes of astrocytes, choroid plexus and ependyma. AQP3, AQP5 and AQP8 had similar distribution patterns in piriform cortex, choroid plexus, hippocampus and dorsal thalamus. AQP4 and AQP9 were widely expressed in the rat brain and distributed in the subpial processes of astrocytes, ependyma, dorsal thalamus, hippocampus, white matter, suprachiasmatic nucleus (SCN) and supraoptic nucleus. AQP3, AQP4, AQP5, AQP8 and AQP9 were found in the Bergmann glial cells of cerebellum, cochlear nucleus and trapezoid nuclei. The distinct localization of various AQPs in cerebrum and the similarities of distribution patterns within cerebellum, cochlear nucleus and trapezoid nuclei suggest that AQPs may play an important role in maintaining the specific microenvironments of the brain.

Abstract 289: Associations between germline genotype and efficacy and safety outcomes in a phase III study of sunitinib (SU) and FOLFIRI in metastatic colorectal cancer (mCRC)

Introduction: SU is an oral, multitargeted inhibitor of VEGFRs, PDGFRs, KIT, FLT3, CSF-1R and RET. In a phase III mCRC study, adding SU to FOLFIRI did not improve progression-free survival (PFS) vs. FOLFIRI/placebo. Potential correlations were investigated between germline genotype and safety/efficacy endpoints among patients (pts) in this trial.

Methods: Blood sample donation for genotype analysis was optional. Selection of genes and polymorphisms was based on prior reported associations. Twenty-one single-nucleotide polymorphisms (SNPs) in 10 genes (VEGF-A, VEGFR-2, CYP1A1, ABCG2, ABCB1, ABCC2, MTHFR, UGT1A1, FLT1 and FLT3) were analyzed by TaqMan allelic discrimination assay or fragment analysis, using DNA isolated from peripheral blood samples. All 21 polymorphisms were analyzed for associations with efficacy (PFS; overall survival [OS]) and selected safety endpoints. Results were adjusted for multiple testing of SNPs in linkage disequilibrium.

Results: Genotyping was performed in 139/768 pts (18%). Age and gender were similar between genotyped and non-genotyped pts, but the genotyped subset had fewer non-Caucasians (13% vs. 39%; Fisher's exact P&lt;0.0001). Therefore, the statistical analysis reported here included Caucasians only. OS was superior in genotyped vs. non-genotyped pts (log rank P&lt;0.0001). For the FOLFIRI/placebo arm only, the ABCC2 gene SNP rs717620 was associated with increased grade 3/4 diarrhea for those with the T allele (0/37 for C/C, 2/15 for C/T, 2/2 for T/T; Fisher's exact P=0.0003), and remained statistically significant after multiple testing adjustment. In the SU/FOLFIRI arm only, the common homozygous genotype A/A in the CYP1A1 gene at rs1048943 was associated with increased grade 3/4 neutropenia (39/59 for A/A, 1/6 for A/G, # of G/G = 0; Fisher's exact P=0.028), but lost significance after multiple testing adjustment. In the FOLFIRI/placebo arm only, a weak association was observed between poorer PFS and the common homozygous genotype T/T for the rs1045642 SNP (C3435T) in the ABCB1 gene (median [T/T] = 36 weeks [95% CI 24.9-40.6]; median [T/C] = 45 weeks [41.9-83.6]; median [C/C] = 55.1 weeks [31.8-55.1], HR [T/C vs. T/T] = 0.21 [95% CI 0.07-0.64]; HR [C/C vs. T/T] = 0.23 [95% CI 0.07-0.81]; log rank P=0.008; not significant after multiple testing adjustment).

Conclusions: Presence of the T allele in the ABCC2 gene at rs717620 was associated with increased risk of grade 3/4 diarrhea in a small number of Caucasian pts receiving FOLFIRI/placebo. No significant associations were identified between genotype and safety/efficacy endpoints in pts who received SU/FOLFIRI. As OS was superior in genotyped vs. non-genotyped pts, correlative findings may not be extrapolated beyond the genotyped subset. Further analysis of baseline characteristics is underway in the genotyped group to investigate this difference.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 289. doi:10.1158/1538-7445.AM2011-289

Mammographic density and its interaction with other breast cancer risk factors in an Asian population

BACKGROUND

Joint effects of mammographic density and other risk factors on breast cancer risk remain unclear.

METHODS

From The Singapore Breast Screening Project, we selected 491 cases and 982 controls. Mammographic density was measured quantitatively. Data analysis was by conditional logistic regression.

RESULTS

Density was a significant risk factor, adjusting for other factors. Density of 76-100% had an odds ratio of 5.54 (95% CI 2.38-12.90) compared with 0-10%. Density had significant interactions with body mass index and oral contraceptive use (P=0.02).

CONCLUSIONS

Percent density increases breast cancer risk in addition to effects of other risk factors, and modifies the effects of BMI and OCs.

Computer Simulation of Displacement Cascades in α-Zirconium

The damage produced in α-zirconium at 100 K by displacement cascades with energy up to 20 keV has been investigated by MD simulations. In agreement with modelling of fcc and bcc metals, the defect production efficiency in zirconium is well below the NRT estimate. The number and size of clusters, both vacancy and interstitial, are increased by increasing PKA energy, and clusters containing up to 25 interstitials and 30 vacancies were formed by 20 keV cascades. Most interstitial clusters have dislocation character with perfect Burgers vectors of the form 1/3<1120>, but a few metastable clusters are formed and are persistent over the timescale of MD simulations. Collapse of the 30-vacancy cluster to a faulted loop on the prism plane was found to occur over a period of more than 100 ps

Large Area Printing of Organic Transistors via a High Throughput Dry Process

Organic electronic systems offer the advantage of low weight and flexibility at potentially lower cost. Although the fabrication of functioning plastic transistors using approaches such as ink jet, lithography and stamping has been described i1–3, chemically compatible materials that allow for the sequential application of liquid layers is a technical barrier. Material issues maybe the Achilles heel of ultimately printing organic electronic devices as newspapers today, at high speeds and in a reel to reel process. We introduce a novel process–thermal transfer–a non-lithographic technique that enables printing multiple, successive layers via a dry additive process. This method is capable of patterning a range of organic materials at high speed over large areas with micron size resolution and excellent electrical performance. Such a dry, potentially reel-to-reel printing method may provide a practical route to realizing the expected benefits of plastics for electronics. We illustrate the viability of thermal transfer and the ability to develop suitable printable organics conductors by fabricating a functioning 4000 cm2 transistor array.