Search for dark matter candidates and large extra dimensions in events with a photon and missing transverse momentum in pp collision data at sqrt[s]=7 TeV with the ATLAS detector

Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 4.6 fb(-1) are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates.

Hypersensitivity reaction studies of a polyethoxylated castor oil-free, liposome-based alternative paclitaxel formulation

The commercial drug paclitaxel (Taxol) may introduce hypersensitivity reactions associated with the polyethoxylated castor oil-ethanol solvent. To overcome these problems, we developed a polyethoxylated castor oil-free, liposome-based alternative paclitaxel formulation, known as Lipusu. In this study, we performed in vitro and in vivo experiments to compare the safety profiles of Lipusu and Taxol, with special regard to hypersensitivity reactions. First, Swiss mice were used to determine the lethal dosages, and then to evaluate hypersensitivity reactions, followed by histopathological examination and enzyme-linked immunosorbent assays (ELISAs) of serum SC5b-9 and lung histamine. Additionally, healthy human serum was used to analyze in vitro complement activation. Finally, an MTT assay was used to determine the in vitro anti-proliferation activity. Our data clearly showed that Lipusu displayed a much higher safety margin and did not induce hypersensitivity or hypersensitivity-related lung lesions, which may be associated with the fact that Lipusu did not activate complement or increase histamine release in vivo. Moreover, Lipusu did not promote complement activation in healthy human serum in vitro, and demonstrated anti-proliferative activity against human cancer cells, similar to that of Taxol. Therefore, the improved formulation of paclitaxel, which exhibited a much better safety profile and comparable cytotoxic activity to Taxol, may bring a number of benefits to cancer patients.

Wortmannin reduces metastasis and angiogenesis of human breast cancer cells via nuclear factor-κB-dependent matrix metalloproteinase-9 and interleukin-8 pathways

OBJECTIVE

To investigate whether inhibition of Akt phosphorylation by the phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin, reduces metastasis and angiogenesis in a human breast cancer cell line via nuclear factor (NF)-κB-dependent matrix metalloproteinase (MMP)-9 and interleukin (IL)-8 pathways.

METHODS

MDA-MB-231 cells were treated with wortmannin 0-200 nM for 4 h. Restoration of Akt activity was evaluated by transfection of cells with constitutively active myristoylated Akt (myr-Akt). NF-κB, MMP-9 and IL-8 proteins were detected by electrophoretic mobility shift assay, Western blot or enzyme-linked immunosorbent assay. The chicken embryo chorio-allantoic membrane assay, cell motility and migration assays were used to evaluate angiogenesis and invasion in vitro. A mouse pseudo metastatic breast cancer model was used to assess the effects of wortmannin on metastasis and angiogenesis in vivo.

RESULTS

Wortmannin inhibited the phosphorylation of Akt, upregulation of NF-κB, MMP-9, IL-8, and in vitro cell invasion and angiogenesis, in a dose-dependent manner. Transfection of myr-Akt reversed the cellular and biochemical effects of wortmannin in vitro. Wortmannin also significantly inhibited tumour metastasis and angiogenesis in vivo.

CONCLUSION

The findings of the present study suggest that wortmannin inhibits metastasis and angiogenesis in breast cancer cells via PI3K/Akt/NF-κB-mediated MMP-9 and IL-8 signalling pathways.

Levels of components of the urokinase-type plasminogen activator system are related to chronic obstructive pulmonary disease parenchymal destruction and airway remodelling

OBJECTIVE

Retrospective study to investigate levels of components of the urokinase-type plasminogen activator (uPA) system in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Peripheral lung tissue was obtained from patients who underwent surgical resection for benign lung diseases: 16 patients with COPD, 10 controls without lung function impairment who were smokers, and 10 controls without lung function impairment who were nonsmokers. Immunohistochemical staining for uPA, uPA receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) was quantified. Airway remodelling (collagen; detected by Sirius red staining), lung function (determined by spirometry) and emphysema (alveolar destruction; percentage of low attenuation areas on computed tomography scan) were evaluated.

RESULTS

uPA, uPAR and PAI-1 were significantly different in structural lung cells and pulmonary macrophages from patients with COPD compared with controls. There were significant positive correlations between collagen levels and uPA and PAI-1, and between uPA and degree of emphysema. There were significant inverse correlations between lung function and uPA, uPAR and PAI-1.

CONCLUSION

Correlations between components of the uPA system and lung function, small airway fibrosis and emphysema indicate a role for the uPA system in COPD.

Electrocatalytic degradation kinetic of 4-chlorophenol by the Pd/C gas-diffusion electrode system

A Pd/C gas-diffusion cathode which generated H2O2 through a two-electron reduction process of fed oxygen molecule was used to degrade 4-chlorophenol in an undivided electrolysis device. The kinetics of 4-chlorophenol degradation has been investigated by the electrochemical oxidation processes. By inspecting the relationship between the rate constants (k) and influencing factors, using first-order kinetics to describe the electrochemical oxidation process of 4-chlorophenol, a kinetic model of 4-chlorophenol degradation process was proposed to calculate the 4-chlorophenol effluent concentration: C = C0 exp( -3:76 × 10(-6) C(-0.5)0 J(2) M(-0.7) Q(0.17) Dt). It was found that the electrocatalytic degradation rate of 4-chlorophenol was affected by current density, electrode distance, air-feeding rate, electrolyte concentration and initial 4-chlorophenol concentration. The kinetics obtained from the experiments under corresponding electrochemical conditions could provide an accurate estimation of 4-chlorophenol effluent concentration and lead to better design of the electrochemical reactor.

Search for magnetic monopoles in sqrt[s]=7 TeV pp collisions with the ATLAS detector

This Letter presents a search for magnetic monopoles with the ATLAS detector at the CERN Large Hadron Collider using an integrated luminosity of 2.0  fb(-1) of pp collisions recorded at a center-of-mass energy of sqrt[s]=7  TeV. No event is found in the signal region, leading to an upper limit on the production cross section at 95% confidence level of 1.6/ϵ  fb for Dirac magnetic monopoles with the minimum unit magnetic charge and with mass between 200 GeV and 1500 GeV, where ϵ is the monopole reconstruction efficiency. The efficiency ϵ is high and uniform in the fiducial region given by pseudorapidity |η|<1.37 and transverse kinetic energy 600-700<E(kin)sinθ<1400  GeV. The minimum value of 700 GeV is for monopoles of mass 200 GeV, whereas the minimum value of 600 GeV is applicable for higher mass monopoles. Therefore, the upper limit on the production cross section at 95% confidence level is 2 fb in this fiducial region. Assuming the kinematic distributions from Drell-Yan pair production of spin-1/2 Dirac magnetic monopoles, the efficiency is in the range 1%-10%, leading to an upper limit on the cross section at 95% confidence level that varies from 145 fb to 16 fb for monopoles with mass between 200 GeV and 1200 GeV. This limit is weaker than the fiducial limit because most of these monopoles lie outside the fiducial region.

Identification of Two Novel ERCC6 Mutations in Old Order Amish with Cockayne Syndrome

Cockayne syndrome (CS) is a rare autosomal recessive disorder characterized by progressive multisystem degeneration and segmental premature aging. Mutations in the DNA repair gene ERCC6 are responsible for the majority of CS cases reported. In this study, we identified 4 patients presenting with CS from 2 Old Order Amish families. Sequence analysis of the ERCC6 gene revealed 2 novel mutations associated with the disorder in these patients. The patients from family 1 were homozygous for a splice-site mutation, c.2709 + 1G>T, in intron 14 of ERCC6, whereas the patients from family 2 were compound heterozygous for c.2709 + 1G>T and a short deletion in exon 5 (c.1293_1320del). Our findings provide evidence of allelic heterogeneity in Old Order Amish, which is extremely uncommon for a rare condition in an isolated founder population.

Rapid identification of Sporothrix schenckii in biopsy tissue by PCR

BACKGROUND

The dimorphic fungus Sporothrix schenckii is the etiological agent of sporotrichosis, an important cutaneous mycosis with a worldwide distribution. At present, it is challenging to rapidly discover and identify Sporothrix schenckii in biopsy tissues nowadays.

AIMS

To explore new methods for rapid diagnosis of sporotrichosis.

MATERIALS AND METHODS

We screened specific primers for Sporothrix schenckii using 50 clinical isolates from patients with sporotrichosis. DNA was extracted from the lesions of 30 cases of clinically suspected sporotrichosis using the Graham s method of CTAB and amplified by PCR using the screened specific primers.

RESULTS

The primer S2-R2 was applicable for the identification of S. schenckii from different geographic areas and clinical types with high specificity and sensitivity. Twenty-five out of the thirty cases (83.3%) amplified using the primer S2-R2 showed positive bands. Further positive bands were observed in 95.6% of cases tested positive by fungal culture.

CONCLUSIONS

Using the PCR technique and specific primers, we developed a new diagnostic method that can rapidly diagnose sporotrichosis with tissues obtained from clinical biopsies.

Abstract PD02-04: Automated Quantitative RNA In Situ Hybridization for Resolution of Equivocal and Heterogeneous ERBB2 (HER2) Status in Invasive Breast Carcinoma

Background: Breast carcinomas that demonstrate a heterogeneous ERBB2 (HER2) status or equivocal results by both immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) present diagnostic challenges for which there is neither a standard methodology to achieve resolution in the clinical laboratory nor a uniform approach to management. We assessed the feasibility of using a novel automated and quantitative HER2 mRNA bright field in situ hybridization (ISH) assay capable of single molecule detection to determine HER2 status in invasive breast carcinomas that demonstrated significant tumor heterogeneity or failed to be resolved by standard IHC and FISH algorithmic testing.

Design: Formalin-fixed, paraffin-embedded (FFPE) breast carcinomas from a non-consecutive series of 163 patients were analyzed for HER2 mRNA using a fully automated bright field RNA ISH assay (RNAscope, Advanced Cell Diagnostics, Hayward, CA). Cases were assigned into either a training set (n = 34) or a validation set (n = 129) and analyzed by both Q-RT-PCR and RNAscope. automated image analysis was used to numerate the punctate signal dots per cell in RNAscope-stained slides. A HER2 mRNA score based on single-cell quantification by RNAscope was developed and correlated to HER2 FISH and HER2 mRNA Q-RT-PCR results. A simple cutoff value was derived using the training set and applied to the validation set.

Results: Evaluable HER2 results were obtained for 154 cases (94.5%) by RNAscope and 163 cases (100%) by Q-RT-PCR. In the training set, both FISH/IHC positive and negative cases were definitively separated by both Q-RT-PCR and RNAscope. HER2 mRNA dots per cell correlated strongly to FISH (Spearman r=0.77) and Q-RT-PCR (r = 0.81). Application of both methods to the validation set resulted in correct identification of 31/31 positive cases and 41/43 negative (overall concordance=97.3%) for both RNAscope and Q-RT-PCR. RNAscope showed a significant advantage over Q-RT-PCR in correctly identifying cases equivocal by FISH that were resolved by reflex IHC testing. RNAscope classified 7 of 26 (26.9%) FISH/IHC double equivocal cases as positives. In cases with HER2 protein heterogeneity, RNAscope showed a 100% concordance with FISH results, whereas Q-RT-PCR showed a 42.9% concordance.

Conclusion: RNAscope analysis of HER2 mRNA is an effective means to resolve HER2 status in double equivocal cases and cases that demonstrate heterogeneity. Automation and image analysis-based quantification minimize analytical and post-analytical variability. Quantification of single RNA transcripts in situ at single-cell level demonstrates superiority over qRTPCR and great potential in predictive biomarker analysis. Further studies of larger cohorts correlating clinical response with HER2 mRNA expression in situ are warranted.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD02-04.

Ductilizing bulk metallic glass composite by tailoring stacking fault energy

Martensitic transformation was successfully introduced to bulk metallic glasses as the reinforcement micromechanism. In this Letter, it was found that the twinning property of the reinforcing crystals can be dramatically improved by reducing the stacking fault energy through microalloying, which effectively alters the electron charge density redistribution on the slipping plane. The enhanced twinning propensity promotes the martensitic transformation of the reinforcing austenite and, consequently, improves plastic stability and the macroscopic tensile ductility. In addition, a general rule to identify effective microalloying elements based on their electronegativity and atomic size was proposed.

microRNA-7 is a novel inhibitor of YY1 contributing to colorectal tumorigenesis

Using microRNA (miRNA) expression array, we identified that miR-7 was deregulated in colorectal cancer (CRC). We studied the biological role and molecular target of miR-7 in CRC. miR-7 was downregulated in six out of seven colon cancer cell lines. Ectopic expression of miR-7 suppressed colon cancer cell proliferation (P<0.05), induced apoptosis (P<0.05) and caused cell-cycle arrest in G1 phase (P<0.05). The tumor suppressive function of miR-7 was further confirmed in nude mice (P<0.05). The 3'-untranslated region (3'UTR) of Yin Yang 1 (YY1) mRNA contains an evolutionarily conserved miR-7 binding site using in silico searches, luciferase reporter assay and western blot analysis confirmed that miR-7 directly bound to YY1 3'UTR to negatively regulate the protein expression of YY1 in colon cancer cell lines HCT116 and LOVO. Intriguingly, knock-down of YY1 in three colon cancer cell lines (HCT116, LOVO and DLD1) consistently suppressed cell proliferation (P<0.01) and induced apoptosis (P<0.01), indicating the opposite functions of miR-7 and YY1 in CRC. Consistent with these data, ectopic expression of YY1 promoted cell growth by increasing proliferation (P<0.01) and suppressing apoptosis (P<0.001). The tumorigenic ability of YY1 was further confirmed in vivo in xenograft-nude mouse model (P<0.01). In addition, pathway analyses revealed that the oncogenic effect by YY1 was associated with inhibiting p53 and modulating its downstream effectors p15, caspase cascades and C-Jun, and activating Wnt signaling pathway through activating β-catenin, anti-apoptotic survivin and fibroblast growth factor 4. Furthermore, multivariate analysis revealed that patients with YY1 protein high expression had a significant decrease in overall survival, and Kaplan-Meier survival curves showed that these patients had significantly shorter survival than others (P<0.0001). In conclusion, MiR-7 is a novel miRNA with tumor suppressive function in colon cancer by targeting oncogenic YY1. YY1 promotes colon cancer growth through inhibiting p53 and promoting Wnt signaling pathways and serves as an independent prognostic biomarker for CRC patients.

Pioglitazone attenuates myocardial ischemia-reperfusion injury via up-regulation of ERK and COX-2

Our previous study demonstrated that the peroxisome proliferator-activated receptor (PPAR) γ agonist, pioglitazone (PIO), may be cardioprotective against ischemia-reperfusion injury; however, modulation of p42/p44 extracellular signal-regulated kinases (ERK1/2) and cyclooxygenase (COX)-2 by PIO in the myocardium with respect to ischemia-reperfusion (I/R) is only partially understood. We determined if PIO reduces I/R-induced apoptosis in cardiomyocytes, and whether or not this protective effect is due to modulation of ERK1/2 and COX-2. Sixty male Sprague-Dawley rats were randomized and assigned to 1 of 6 groups: I/R; I/R + PIO (5 mg•kg(-1)•day(-1)); I/R + PIO (10 mg•kg(-1)•day(-1)); I/R + PIO (10 mg•kg(-1)•day(-1)) + the ERK1/2 inhibitor, PD98059; I/R + PIO ( 10 mg•kg(-1)•day(-1)) + GW9662;and I/R + PD98059. Rats underwent 30 min of myocardial ischemia and 120 min of reperfusion, and then hearts were harvested for analysis. RT-PCR and Western blotting were performed to detect expression of ERK1/2 and COX-2. The number of TUNEL-positive cardiomyocytes and NEC in the PIO groups (5 and 10 mg•kg(-1)•day(-1)) was much lower than the I/R group. The cardioprotective effect of PIO was abrogated by PD98059 and GW9662. Phosphorylation of ERK1/2 and COX-2 was increased in the PIO-treated group compared with the I/R group. GW9662 reversed the expression of ERK1/2 and COX- 2 phosphorylation induced by PIO. PD98059 reversed the expression of COX-2 induced by PIO. PIO was shown to be cardioprotective in an I/R injury model in rats via inhibition of cardiomyocyte apoptosis. PIO limited the infarct size in a PPAR-γ-dependent manner. These results show that PIO triggers the MAPK signaling pathway involving ERK1/2 using COX-2 as the downstream target.

Advance in multi-hit detection and quantization in atom probe tomography

The preferential retention of high evaporation field chemical species at the sample surface in atom-probe tomography (e.g., boron in silicon or in metallic alloys) leads to correlated field evaporation and pronounced pile-up effects on the detector. The latter severely affects the reliability of concentration measurements of current 3D atom probes leading to an under-estimation of the concentrations of the high-field species. The multi-hit capabilities of the position-sensitive time-resolved detector is shown to play a key role. An innovative method based on Fourier space signal processing of signals supplied by an advance delay-line position-sensitive detector is shown to drastically improve the time resolving power of the detector and consequently its capability to detect multiple events. Results show that up to 30 ions on the same evaporation pulse can be detected and properly positioned. The major impact of this new method on the quantization of chemical composition in materials, particularly in highly-doped Si(B) samples is highlighted.