Tumor cell survival dependence on the DHX9 DExH-box helicase

The ATP-dependent DExH/D-box helicase DHX9 is a key participant in a number of gene regulatory steps, including transcriptional, translational, microRNA-mediated control, DNA replication, and maintenance of genomic stability. DHX9 has also been implicated in tumor cell maintenance and drug response. Here, we report that inhibition of DHX9 expression is lethal to human cancer cell lines and murine Eµ−Myc lymphomas. Using a novel conditional shDHX9 mouse model, we demonstrate that sustained and prolonged (6 months) suppression of DHX9 does not result in any deleterious effects at the organismal level. Body weight, blood biochemistry, and histology of various tissues were comparable to control mice. Global gene expression profiling revealed that although reduction of DHX9 expression resulted in multiple transcriptome changes, these were relatively benign and did not lead to any discernible phenotype. Our results demonstrate a robust tolerance for systemic DHX9 suppression in vivo and support the targeting of DHX9 as an effective and specific chemotherapeutic approach.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Time series study of a 17-year record of (7)Be and (210)Pb fluxes in northern Taiwan using ensemble empirical mode decomposition

Using the ensemble empirical mode decomposition (EEMD) and a significance test method, we have analyzed time series data on the fluxes of (7)Be and (210)Pb collected over a span of 17 y in Northern Taiwan. Among nine intrinsic mode functions (IMFs) extracted from the method five (IMF4-8) are non-trivial for (210)Pb and have adequate S/N with significant power in localized windows around the periodicities of 0.5 y, 1 y, 2 y, 5 y, and 11 y, respectively. For (7)Be, IMF5 and IMF8 with periods around 1 y and 11 y, respectively, have adequate S/N. The semi-annual and annual cycles represented by IMF4 and IMF5, respectively, are dominated by East Asian monsoon. The sum of IMF6 and IMF7 reveals an inter-annual cycle where both (7)Be and (210)Pb fluxes are well-correlated with the East Asian winter monsoon index (EAWMI). The close tracking of the (210)Pb and (7)Be in IMF8 cases may reflect an 11 y cycle; implying that it is caused by common climatologic factors, likely related to solar cycle, rather than their distinct production modes.

Do labetalol and methyldopa have different effects on pregnancy outcome? Analysis of data from the Control of Hypertension In Pregnancy Study (CHIPS) trial

OBJECTIVE

To compare pregnancy outcomes, accounting for allocated group, between methyldopa-treated and labetalol-treated women in the CHIPS Trial (ISRCTN 71416914) of 'less tight' versus 'tight' control of pregnancy hypertension.

DESIGN

Secondary analysis of CHIPS Trial cohort.

SETTING

International randomised controlled trial (94 sites, 15 countries).

POPULATION OR SAMPLE

Of 987 CHIPS recruits, 481/566 (85.0%) women treated with antihypertensive therapy at randomisation. Of 981 (99.4%) women followed to delivery, 656/745 (88.1%) treated postrandomisation.

METHODS

Logistic regression to compare outcomes among women who took methyldopa or labetalol, adjusted for the influence of baseline factors.

MAIN OUTCOME MEASURES

CHIPS primary (perinatal loss or high level neonatal care for >48 hours) and secondary (serious maternal complications) outcomes, birthweight <10th centile, severe maternal hypertension, pre-eclampsia and delivery at <34 or <37 weeks.

RESULTS

Methyldopa and labetalol were used commonly at randomisation (243/987, 24.6% and 238/987, 24.6%, respectively) and post-randomisation (224/981, 22.8% and 433/981, 44.1%, respectively). Following adjusted analyses, methyldopa (versus labetalol) at randomisation was associated with fewer babies with birthweight <10th centile [adjusted odds ratio (aOR) 0.48; 95% CI 0.20-0.87]. Methyldopa (versus labetalol) postrandomisation was associated with fewer CHIPS primary outcomes (aOR 0.64; 95% CI 0.40-1.00), birthweight <10th centile (aOR 0.54; 95% CI 0.32-0.92), severe hypertension (aOR 0.51; 95% CI 0.31-0.83), pre-eclampsia (aOR 0.55; 95% CI 0.36-0.85), and delivery at <34 weeks (aOR 0.53; 95% CI 0.29-0.96) or <37 weeks (aOR 0.55; 95% CI 0.35-0.85).

CONCLUSION

These nonrandomised comparisons are subject to residual confounding, but women treated with methyldopa (versus labetalol), particularly those with pre-existing hypertension, may have had better outcomes.

TWEETABLE ABSTRACT

There was no evidence that women treated with methyldopa versus labetalol had worse outcomes.

Vitamin D supplementation and antibacterial immune responses in adolescents and young adults with HIV/AIDS

Human monocytes activated by toll-like receptor 2/1 ligand (TLR2/1L) show enhanced expression of the vitamin D receptor (VDR) and the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). The resulting intracrine conversion of precursor 25-hydroxyvitamin D3 (25OHD) to active 1,25-dihydroxyvitamin D (1,25(OH)2D) can stimulate expression of antibacterial cathelicidin (CAMP). To determine whether this response is functional in HIV-infected subjects (HIV+ ), serum from HIV+ subjects pre- and post-vitamin D supplementation was utilized in monocyte cultures with or without TLR2/1L. Expression of CYP27B1 and VDR was enhanced following treatment with TLR2/1L, although this effect was lower in HIV+ vs HIV- serum (p<0.05). CAMP was also lower in TLR2/1L-treated monocytes cultured in HIV+ serum (p<0.01). In a dose study, supplementation of HIV+ subjects with 4000IU or 7000IU vitamin D/day increased serum 25OHD from 17.3±8.0 and 20.6±6.2ng/ml (43nM and 51nM) at baseline to 41.1±12.0 and 51.9±23.1ng/ml (103nM and 130nM) after 12 weeks (both p<0.001). Greater percent change from baseline 25OHD was significantly associated with enhanced TLR2/1L-induced monocyte CAMP adjusted for baseline expression (p=0.009). In a randomized placebo-controlled trial, 7000IU vitamin D/day increased serum 25OHD from 18.0±8.6 to 32.7±13.8ng/ml (45nM and 82nM) after 12 weeks. Expression of CAMP increased significantly from baseline after 52 weeks of vitamin D-supplementation. At this time point, TLR2/1L-induced CAMP was positively associated with percent change from baseline in 25OHD (p=0.029 overall and 0.002 within vitamin D-supplemented only). These data indicate that vitamin D supplementation in HIV-infected subjects can promote improved antibacterial immunity, but also suggest that longer periods of supplementation are required to achieve this.

Analysis of knowledge and attitude surveys to identify barriers and enablers of appropriate antimicrobial prescribing in three Australian tertiary hospitals

BACKGROUND

Antimicrobial stewardship programmes aim to optimise use of antibiotics and are now mandatory in all Australian hospitals.

AIM

We aimed to identify barriers to and enablers of appropriate antimicrobial prescribing among hospital doctors.

METHODS

Two paper-based and one web-based surveys were administered at three Australian university teaching hospitals from March 2010 to May 2011. The 18-item questionnaire recorded doctors’ level of experience, their knowledge regarding the use of common antimicrobials and their attitudes regarding antimicrobial prescribing. Local survey modifications allowed inclusion of specific questions on: infections in intensive care unit patients, clinical microbiology and use of local guidelines.

RESULTS

The respondents (n = 272) were comprised of 96 (35%) registrars, 67 (25%)residents, 57 (21%) interns and 47 (17%) consultant hospital doctors. Forty-one per cent were working in a medical specialty. Identified barriers included: gaps in antimicrobial prescribing knowledge (especially among interns), a lack of awareness about which antimicrobials were restricted and a reliance on senior colleagues to make antimicrobial prescribing decisions. Enablers of optimal prescribing included: an acknowledgement of the need for assistance in prescribing and reported readiness to consult national prescribing guidelines. These results were used to help guide and prioritise interventions to improve prescribing practices.

CONCLUSION

A transferable knowledge and attitudes survey tool can be used to highlight barriers and facilitators to optimal hospital antimicrobial prescribing in order to inform tailored antimicrobial stewardship interventions.

Genetic contributions to variation in general cognitive function: a meta-analysis of genome-wide association studies in the CHARGE consortium (N=53949)

General cognitive function is substantially heritable across the human life course from adolescence to old age. We investigated the genetic contribution to variation in this important, health- and well-being-related trait in middle-aged and older adults. We conducted a meta-analysis of genome-wide association studies of 31 cohorts (N=53,949) in which the participants had undertaken multiple, diverse cognitive tests. A general cognitive function phenotype was tested for, and created in each cohort by principal component analysis. We report 13 genome-wide significant single-nucleotide polymorphism (SNP) associations in three genomic regions, 6q16.1, 14q12 and 19q13.32 (best SNP and closest gene, respectively: rs10457441, P=3.93 × 10(-9), MIR2113; rs17522122, P=2.55 × 10(-8), AKAP6; rs10119, P=5.67 × 10(-9), APOE/TOMM40). We report one gene-based significant association with the HMGN1 gene located on chromosome 21 (P=1 × 10(-6)). These genes have previously been associated with neuropsychiatric phenotypes. Meta-analysis results are consistent with a polygenic model of inheritance. To estimate SNP-based heritability, the genome-wide complex trait analysis procedure was applied to two large cohorts, the Atherosclerosis Risk in Communities Study (N=6617) and the Health and Retirement Study (N=5976). The proportion of phenotypic variation accounted for by all genotyped common SNPs was 29% (s.e.=5%) and 28% (s.e.=7%), respectively. Using polygenic prediction analysis, ~1.2% of the variance in general cognitive function was predicted in the Generation Scotland cohort (N=5487; P=1.5 × 10(-17)). In hypothesis-driven tests, there was significant association between general cognitive function and four genes previously associated with Alzheimer's disease: TOMM40, APOE, ABCG1 and MEF2C.

Rhodococcus aerolatus sp. nov., isolated from subarctic rainwater

A Gram-stain-positive, rod-shaped and non-motile strain, designated PAMC 27367(T), was isolated from rainwater collected on the Bering Sea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Rhodococcus. Phylogenetic analyses revealed that strain PAMC 27367(T) formed a robust clade with the type strains of Rhodococcus rhodnii, Rhodococcus aetherivorans and Rhodococcus ruber with 16S rRNA gene sequence similarities of 96.3 %, 95.8 % and 95.5 %, respectively. Cells of the strain grew optimally at 25 °C and at pH 6.5-7.0 in the presence of 0-2 % (w/v) sea salts. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and three unknown phospholipids. The major cellular fatty acids (>10 %) were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Cell wall analysis showed that strain PAMC 27367(T) contained meso-diaminopimelic acid. The genomic DNA G+C content was 77.1 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic data presented here, we propose a novel species with the name Rhodococcus aerolatus sp. nov., with PAMC 27367(T) ( = KCTC 29240(T) = JCM 19485(T)) as the type strain.

Retinoschisin gene therapy in photoreceptors, Müller glia or all retinal cells in the Rs1h-/- mouse

X-linked retinoschisis, a disease characterized by splitting of the retina, is caused by mutations in the retinoschisin gene, which encodes a secreted cell adhesion protein. Currently, there is no effective treatment for retinoschisis, though viral vector-mediated gene replacement therapies offer promise. We used intravitreal delivery of three different AAV vectors to target delivery of the RS1 gene to Müller glia, photoreceptors, or multiple cell types throughout the retina. Müller glia radially span the entire retina, are accessible from the vitreous, and remain intact throughout progression of the disease. However, photoreceptors, not glia, normally secrete retinoschisin. We compared the efficacy of rescue mediated by retinoschisin secretion from these specific subtypes of retinal cells in the Rs1h−/− mouse model of retinoschisis. Our results indicate that all three vectors deliver the RS1 gene, and that several cell types can secrete retinoschisin, leading to transport of the protein across the retina. The greatest long-term rescue was observed when photoreceptors produce retinoschisin. Similar rescue was observed with photoreceptor-specific or generalized expression, though photoreceptor secretion may contribute to rescue in the latter case. These results collectively point to the importance of cell targeting and appropriate vector choice in the success of retinal gene therapies.

The use of a neutral peptide aptamer scaffold to anchor BH3 peptides constitutes a viable approach to studying their function

The B-cell CLL/lymphoma-2 (Bcl-2) family of proteins are important regulators of the intrinsic pathway of apoptosis, and their interactions, driven by Bcl-2 homology (BH) domains, are of great interest in cancer research. Particularly, the BH3 domain is of clinical relevance, as it promotes apoptosis through activation of Bcl-2-associated x protein (Bax) and Bcl-2 antagonist killer (Bak), as well as by antagonising the anti-apoptotic Bcl-2 family members. Although investigated extensively in vitro, the study of the BH3 domain alone inside cells is more problematic because of diminished secondary structure of the unconstrained peptide and a lack of stability. In this study, we report the successful use of a novel peptide aptamer scaffold – Stefin A quadruple mutant – to anchor and present the BH3 domains from Bcl-2-interacting mediator of cell death (Bim), p53 upregulated modulator of apoptosis (Puma), Bcl-2-associated death promoter (Bad) and Noxa, and demonstrate its usefulness in the study of the BH3 domains in vivo. When expressed intracellularly, anchored BH3 peptides exhibit much the same binding specificities previously established in vitro, however, we find that, at endogenous expression levels, Bcl-2 does not bind to any of the anchored BH3 domains tested. Nonetheless, when expressed inside cells the anchored PUMA and Bim BH3 α-helices powerfully induce cell death in the absence of efficient targeting to the mitochondrial membrane, whereas the Noxa helix requires a membrane insertion domain in order to kill Mcl-1-dependent myeloma cells. Finally, the binding of the Bim BH3 peptide to Bax was the only interaction with a pro-apoptotic effector protein observed in this study.

Abstract P1-01-03: Interim analysis of the validation study on the clinical usefulness of the ICG fluorescence method for detecting sentinel lymph nodes in early breast cancer compared with the RI method (fICG-BR02)

Background: Sentinel lymph node (SLN) biopsy guided by radioisotope (RI), blue dye or in combination methods is common. A high identification rate is reported for the RI-guided method. On the other hand, it has the demerits of radiation exposure, being expense, and it can only be used in a radiation-controlled area. The blue dye method, however, is safe and inexpensive, but the identification rate is lower compared with the RI method and requires training. The indocyanine green (ICG) fluorescent method involves the application of the fluorescing property. Lymph flow can be traced from outside the body with a photodynamic eye (PDE) camera simultaneously with an operation procedure. The ICG method is safe, inexpensive and requires little training, therefore its use will be widely permitted in any general hospitals. Recently, based on several retrospective clinical trials, the identification rate with the ICG fluorescent method has been reported to be equal to or greater than the RI method. The purpose of this multicenter study is to prospectively assess the diagnostic performance of SLN biopsy using the ICG fluorescence technique compared with RI.

Materials and methods: In this validation study, the patients aged from 20 to 75 years-old with operable primary invasive breast cancer (cT1c-2N0M0) have been nominated and required the written informed consent.

All candidates underwent SLN biopsy using the combined methods with RI and ICG fluorescence. The target sample size was 840 patients to evaluate the sensitivity of ICG method as a primary endpoint, and after 200 patients were enrolled we analyzed the identification rate and the SLN-positive rate of the RI and ICG methods respectively as the interim analysis planned beforehand.

Results: Two hundred eligible patients were enrolled in this study from May 2011 to February 2012. Their median age was 53.0 years (range: 27-74 years). The number of patients with cT1c was 106 and that with cT2 was 94. The identification rate of the RI and the ICG method was 97% (194/200) and 96% (192/200) respectively. Of the 194 patients that were identified with the RI method, 186 (95.9%) were also identified with the ICG method. ICG identified 6 patients that were not identified by RI. On the other hand, RI identified 8 patients that were not identified by ICG. The SLN-positive rate was 25.5% (51/200). This rate was higher than we expected. Of the 51 patients with positive metastatic lymph nodes, 23 patients (21.7%) had cT1c breast cancer and 28 (29.8%) had cT2 breast cancer. The positive rate of the first SLN was 23.5% (47/200) and tumor cells skipped to the second or further tier in four cases (2%).

Conclusions: The ICG-guided SLN biopsy procedure achieved a high identification rate almost equal to that with the RI method. Using this combination method, the identification rate was 100%. We will assess the sensitivity and the additive effect of combining the ICG fluorescence method with the RI method, etc., when all 840 patients have been enrolled (UMIN000005167).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-03.

Implications of local osteoporosis on the efficacy of anti-resorptive drug treatment: a 3-year follow-up finite element study in risedronate-treated women

The existence of local osteoporosis necessitates patient-specific analysis. Lower and higher ranges of local buckling ratio were found at femoral necks for adequate and inadequate drug response groups, respectively (grouped based on fracture loads). Management of hip fracture risk should be targeted at local geometric abnormalities causing instability.

INTRODUCTION

Hip fracture amongst the elderly is a growing concern especially with improvements in living standards and increasing lifespan. Approximately half of the total hip fractures result from those without osteoporosis. This escalates the need to observe local osteoporosis. By observing the local buckling ratio (BR) in the femoral neck in ten risedronate-treated subjects over 3 years, we discovered that subjects with improved fracture loads, as predicted by finite element (FE) analysis, were associated with lower local BR and vice versa.

METHODS

The 3D models of the left proximal femurs were generated, and local BR values at 30° intervals were obtained from femoral neck slices by measuring the respective mean cortical thickness and mean outer radius. Following geometric analysis, structural strength was examined with FE analysis where critical fracture loads (F cr) were acquired from sideways fall load simulations.

RESULTS

We classified subjects in three groups according to the change in F cr: adequate (+20 %), inadequate (-22 %) and indefinite (-2 %) drug response groups. A common striking feature was that lower and higher ranges of local BR values (baseline year) were found for adequate (min = 2.14, max = 8.04) and inadequate (min = 1.72, max = 11.38) drug response groups, respectively.

CONCLUSIONS

Subjects in the inadequate drug response group exhibited high local BR at the supero-anterior and supero-posterior regions. These high local BR values coincided with FE-predicted critical strain regions, whereas subjects from the adequate drug response group showed significantly reduced strain regions. The superiority of coupling geometry (BR) with structure (F cr) over bone mineral density measurements alone by monitoring local osteoporosis has been illustrated.

Impact of early surfactant and inhaled nitric oxide therapies on outcomes in term/late preterm neonates with moderate hypoxic respiratory failure

OBJECTIVE

We conducted a post-hoc analysis of early inhaled nitric oxide (iNO)-randomized controlled trial data to identify associations pertinent to the management of moderate hypoxic respiratory failure in term/late preterm infants.

STUDY DESIGN

Univariate and multivariate logistic regression analyses were used to determine risk factors for the progression of respiratory failure and extracorporeal membrane oxygenation (ECMO)/death.

RESULT

Among the 299 enrolled infants, oxygenation index (OI) <20 at enrollment (odds ratio 0.52, confidence interval (CI) 0.27 to 0.97) and surfactant use before randomization (odds ratio 0.47, CI 0.24 to 0.91) were associated with decreased ECMO/death rates. Early surfactant use for respiratory distress syndrome, perinatal aspiration syndrome and pneumonia/sepsis was associated with lower risk of ECMO/death (P<0.001). Early iNO (OI 15 to 25) decreased the progression of respiratory failure to OI >30 (P=0.002) and to composite outcome of OI >30 or ECMO/death (P=0.02).

CONCLUSION

This post-hoc analysis suggests that early use of surfactant and iNO in moderate respiratory failure is associated with improved outcomes.