GaN-Based MSM uv Photodetectors

Results obtained from interdigital metal-semiconductor-metal (MSM) type of GaN based UV photodetectors are presented. MSM devices were fabricated using two types of GaN; high-resistive GaN and Mg doped GaN. For the high-resistive GaN detector, the lowest dark current is ∼0.1 nA and the UV responsivity of the device was about 460 AAV at a DC bias of 30 V. The Mg doped GaN exhibited large gains, 1150 A/W at 2.0 V, but at much higher dark currents, 400 nA. The high gain in this device is not well understood but was attributed to an ‘avalanche’ effect and is under investigation. It was found that the surface plasma treatment plays an important role in the device performance. After an appropriate plasma treatment the detectors showed higher responsivity with lower dark current.

DMP1 processing is essential to dentin and jaw formation

Dentin matrix protein 1 (DMP1), an acidic protein that is essential to the mineralization of bone and dentin, exists as proteolytically processed fragments in the mineralized tissues. In this study, we characterized the tooth and jaw phenotypes in transgenic mice containing no wild-type DMP1, but expressing a mutant DMP1 in which Asp(213), a residue at one cleavage site, was replaced by Ala(213) (named "Dmp1-KO/D213A-Tg" mice). The teeth and mandible of Dmp1-KO/D213A-Tg mice were compared with those of wild-type, Dmp1-knockout (Dmp1-KO), and Dmp1-KO mice expressing the normal Dmp1 transgene. The results showed that D213A-DMP1 was not cleaved in dentin, and the expression of D213A-DMP1 failed to rescue the defects in the dentin, cementum, and alveolar bones in the Dmp1-KO mice. These findings indicate that the proteolytic processing of DMP1 is essential to the formation and mineralization of dentin, cementum, and jaw bones.

Search for stopped Gluinos in pp collisions at square root s=7 TeV

The results of the first search for long-lived gluinos produced in 7 TeV pp collisions at the CERN Large Hadron Collider are presented. The search looks for evidence of long-lived particles that stop in the CMS detector and decay in the quiescent periods between beam crossings. In a dataset with a peak instantaneous luminosity of 1×10(32) cm-2 s-1, an integrated luminosity of 10 pb-1, and a search interval corresponding to 62 hours of LHC operation, no significant excess above background was observed. Limits at the 95% confidence level on gluino pair production over 13 orders of magnitude of gluino lifetime are set. For a mass difference mg - mχ1(0) >100 GeV/c2, and assuming BR(g→gχ1(0))=100%, mg < 370 GeV/c2 are excluded for lifetimes from 10 μs to 1000 s.

Impact of operating history on mixed culture fermentation microbial ecology and product mixture

Mixed culture fermentation is an alternative to pure culture fermentation for production of biofuels and valuable products. A glucose-fed, continuous reactor was operated cyclically to a central pH of 5.5 from a number of precedent pHs, from 4.5 to 7.5. At each pH, stable chemical production was reached after 2 retention times and was held for least 2 further retention times prior to the next change. Bacterial groups were identified by phylogenetic analysis of 16S rRNA gene clones. Bacterial community dynamics were monitored by terminal-restriction fragment length polymorphism. More ethanol was produced at high pH, and more butyrate at lower pH. At pH 5.5, the product spectrum was not measurably influenced by precedent pH but showed seemingly random changes. The impact of precedent pH on community structure was more systematic, with clear indications that when the pH was returned to 5.5, the bacterial group that was dominant at the precedent pH remained at high abundance. This result is important, since it indicates a decoupling between microbial function (as indicated by product spectrum), and community structure. More work is needed to determine the longevity of this hysteresis effect. There was evidence that groups retained their ability to re-emerge even after times of low abundance.

Characterization and anti-fouling performance of nano-Al₂O₃/PVDF membrane for Songhua river raw water filtration

Polyvinylidene fluoride (PVDF) flat ultrafiltration membranes modified by nano-sized alumina (Al₂O₃) particles were prepared by phase inversion process and their properties and anti-fouling performances were examined. The influence of three types of natural organic matters on the modified membrane fouling was also studied. Raw water was taken from two different locations, i.e., Harbin and Zhaoyuan, of Songhua River. Dissolved organic compounds in the raw water were fractionated using XAD resins into three fractions, i.e., hydrophobic fraction, transphilic fraction, and hydrophilic fraction (HPI). The three adsorbed compounds were further eluted and dissolved into distilled water respectively to prepare the feed for the fouling tests. All solutions were adjusted to a concentration of 10.6 mg C/L, which equals to the total organic carbon (TOC) of the raw water. Results show that the addition of nano-Al₂O₃ particulars did not affect the inherent traits of the PVDF membranes, however, its surface hydrophilic properties were improved significantly with the addition of nanoparticles and anti-fouling performance was enhanced as well. The HPIs in the Songhua River were the main foulant, causing more fouling to membrane than hydrophobic and transphilic matters.

Randomised clinical trial: a novel rabeprazole extended release 50 mg formulation vs. esomeprazole 40 mg in healing of moderate-to-severe erosive oesophagitis - the results of two double-blind studies

BACKGROUND

Current PPIs may not achieve desired outcomes in some GERD patients due to limited duration of acid inhibition.

AIM

To evaluate a novel rabeprazole extended release (ER), which provides longer duration of drug exposure and acid suppression, in healing and symptomatic resolution of moderate-severe erosive oesophagitis.

METHODS

Patients with LA grade C or D oesophagitis were randomised to rabeprazole-ER 50 mg or esomeprazole 40 mg once daily in two identical 8-week double-blind trials (N = 2130). Two primary endpoints were tested sequentially: (1) healing by 8 weeks [hypothesis: rabeprazole-ER non-inferior to esomeprazole (non-inferiority margin = 8%)], (2) healing by 4 weeks [hypothesis: rabeprazole-ER superior to esomeprazole (P < 0.05)]. The secondary endpoint was sustained heartburn resolution at 4 weeks.

RESULTS

Rabeprazole-ER was non-inferior to esomeprazole in week-8 healing (80.0% vs. 75.0%; 77.5% vs. 78.4%). Week-4 healing (54.8% vs. 50.3%; 50.9% vs. 50.7%) and sustained heartburn resolution (48.3% vs. 48.2%; 53.2% vs. 52.5%) were not significantly different. Post hoc combined results for grade D revealed rabeprazole-ER vs. esomeprazole differences in week-8 healing = 10.4% (95% CI: -1.4%, 22.2%) and week-4 healing = 12.0% (P = 0.048).

CONCLUSIONS

Rabeprazole-ER is as effective as esomeprazole in healing moderate-severe oesophagitis and achieves similar rates of heartburn resolution. Subgroup analysis suggests the possibility of benefit in severe oesophagitis, but this requires further evaluation (ClinicalTrials.gov: NCT00658528 and NCT00658775).

Search for quark compositeness with the dijet centrality ratio in pp collisions at √s=7 TeV

A search for quark compositeness in the form of quark contact interactions, based on hadronic jet pairs (dijets) produced in proton-proton collisions at √s=7 TeV, is described. The data sample of the study corresponds to an integrated luminosity of 2.9 pb(-1) collected with the CMS detector at the LHC. The dijet centrality ratio, which quantifies the angular distribution of the dijets, is measured as a function of the invariant mass of the dijet system and is found to agree with the predictions of the standard model. A statistical analysis of the data provides a lower limit on the energy scale of quark contact interactions. The sensitivity of the analysis is such that the expected limit is 2.9 TeV; because the observed value of the centrality ratio at high invariant mass is below the expectation, the observed limit is 4.0 TeV at the 95% confidence level.

Abstract P5-06-08: Role of Androgen Receptor in Metastasis and Hormone Resistance of Estrogen Receptor Positive Breast Cancer

Background: We have previously developed a novel model of estrogen receptor a (ERa)-positive breast cancer metastasis involving shRNA knockdown of Rho GDIa, an inhibitor of the GTP hydrolyzing enzymes of the Rho family.Also although it is known that androgen receptor (AR) is frequently expressed with ERa in breast tumors, and is generally accepted to be a favorable prognostic factor, its role in tumor progression and metastasis is unknown.

Materials and Methods: shRNA knock down was used to lower endogenous expression of Rho GDIa in ERa-positive MCF-7 cells. Metastasis of the knockdown cells was analyzed by injection into athymic mice followed by histological analysis of isolated tissues. Resistance to Tam was also analyzed in these cells by following tumor growth in injected mice treated with vehicle or Tam. To determine the involvement of specific pathways, western blot analysis was used to determine expression of components of the AR and ERa signaling pathways. Reverse phase protein arrays (RPPA) were also used to analyze global expression of phosphorylated proteins. Results: The MCF-7-Rho GDIa knockdown cells exhibited increased lung metastasis, and both primary and metastatic tumors were resistant to the inhibitory effects of Tam. AR protein was found to be overexpressed in the Rho GDIa knock down cells as well, as confirmed by both western blot and RPPA. AR RNA levels were not increased however, thus post-transcriptional modifications via the Rho pathway may be involved in its up-regulation. In addition, AR protein levels were modulated by estrogen treatment in the knockdown cells, suggesting a role for ER in its regulation.

Discussion: Given that AR was significantly overexpressed with the metastatic and resistant phenotype of these cells, its role in these processes is currently being explored with AR antagonists. AR may represent a clinical target for hormone therapy resistance and metastasis of ERa-positive breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-08.

Abstract P5-06-01: MTA2 and AR Overexpression in ER-Negative Breast Cancer Cells: Roles in Invasion and Metastasis

Background: We have previously shown that overexpression of metastasis associated protein 2 (MTA2) can render estrogen receptor (ER)-positive breast cancer cells hormone-independent through postranscriptional effects on ER acetylation and phosphorylation. Recently we discovered that MTA2 overexpression in ER-negative MDA-MB-231 breast cancer cells enhances invasion and metastasis in athymic nude mice which involves activation of the Rho pathway. It is also known that the androgen receptor (AR) is frequently expressed in breast tumors; however its role in proliferation, invasion, or breast cancer metastasis is poorly understood. Materials and Methods: MTA2 was stably overexpressed in MDA-MB-231 and its levels validated using Western blot analysis. To identify downstream effects due to MTA2 overexpression, we employed reverse phase protein arrays, and Affymetrix expression arrays. Significant changes in gene expression were identified using dCHIP software, and student t tests. Invasion was examined using modified Boyden chamber growth assays, proliferation was assayed using soft agar growth and MTT assays, and metastasis was measured as tumor growth in athymic nude mice. Results: MTA2 overexpression in ER-negative cells enhanced distant and skin metastases in athymic nude mice. In an attempt to identify effectors of MTA2-mediated metastasis, we used RNA microarray and protein array screens, and found that AR was significantly increased. As a control, we employed a rescue of the highly metastatic MTA2-MDA-MB-231 cell phenotype via stable transfection and add-back of Rho GDIa, a gene that was concomitantly down-regulated with MTA2 overexpression. AR levels were significantly reduced with Rho GDIa add-back. To determine if AR was functional in these cells, we used ARE-luciferase reporter assays and discovered that both basal, and agonist (R1881)-induced transcriptional activity were significantly enhanced. The AR antagonist, bicalutamide, was effective at significantly decreasing the invasive potential of MTA2- overexpressing MDA-MB-231 cells In vivo experiments in nude mice with bicalutamide treatment are underway.

Discussion: AR was significantly overexpressed with the aggressive phenotype conferred via MTA2 overexpression. This suggests that blockade of AR action might provide a new therapeutic target to inhibit metastasis of breast cancer cells.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-01.

Abstract S6-9: Expression of Hedgehog Proteins in the Epithelial and Stromal Compartments of Primary Breast Tumors and Its Prognostic Significance

Purpose: Aberrant hedgehog (Hh) signaling has been reported in various cancers including breast cancers and clinical trials targeting this pathway are currently ongoing. Preclinical evidence suggests that increased ligand-dependent Hh signaling in breast tumor epithelial (E) cells cross-talks and activates Hh pathway in the stroma (S) but the clinical implication of this E/S interaction is unknown. We sought to determine the expression of Hh proteins in the E and S compartments of primary breast tumor samples and correlate with clinical outcomes.

Methods: Using tissue microarray (TMA) of ∼500 primary breast cancer samples (OSU 2009C009 A) that includes both primary breast tumor and axillary metastasis, the expression pattern of the key Hh signaling proteins (Shh, Gli-1, SMO, Ptch1) and a target gene of the pathway (BMI1) was determined by immunohistochemistry (IHC) in both the epithelial and stromal tissues and compared to other known prognostic/predictive markers such as age, stage, estrogen/progesterone receptor (ER/PR)/HER2 status and to disease-free survival (DFS). IHC was performed using Benchmark LT automated system from Ventana Medical Systems using previously published methods (Nuovo GJ, Nature protocols, 2009). Scoring was done by combining the intensity and percentage of cells staining with respective antibodies by three independent measurements.

Results: Analysis of a total of 315 primary breast tumors revealed the following percentage of tumors with high expression of Hh proteins in the E/S compartments respectively: Shh (72/31%), Gli-1 (69/53%), SMO (40/64%), and Ptch-1 (93/74%). Analyzing the interaction between the epithelial and stromal expressions of these proteins, we found positive correlation between i) high Shh and SMO in the epithelial cells and Gli-1 in the stroma, and ii) high Gli-1 in the epithelial cells and target protein Bmi1 in the stroma. High intensity staining of Gli-1 in the tumor epithelial cells was significantly associated with higher stage, grade, ER negative status and worse DFS. Adjusting for stage and ER status, tumors with increased epithelial Gli-1 expression was still significantly associated with worse DFS (p=0.0131, survival analysis) when compared to tumors with low expression. In particular, among the ER negative and node positive patients higher Gli-1 expression in epithelial cells was very significantly associated with poor DFS (p= &lt;0.0001). Staining for other target proteins in these tumors is currently ongoing.

Conclusions: We report here for the first time a positive correlation between expression of Hh proteins in the stromal and epithelial compartment of primary breast tumors. Furthermore, we observed that higher Gli-1 expression in the tumor epithelial cells was associated with worse DFS, particularly in the ER negative, node-positive tumors suggesting that aberrant Hh signaling may contribute to drug-resistance and hence a rationale therapeutic target. Further correlative studies between clinical parameters and additional Hh target genes in these tumors are in progress.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S6-9.

Search for dijet resonances in 7 TeV pp collisions at CMS

A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 pb⁻¹ collected by the CMS experiment at the Large Hadron Collider. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E6 diquarks, in specific mass intervals. This extends previously published limits on these models.

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.

Transgenic rescue of enamel phenotype in Ambn null mice

Ameloblastin null mice fail to make an enamel layer, but the defects could be due to an absence of functional ameloblastin or to the secretion of a potentially toxic mutant ameloblastin. We hypothesized that the enamel phenotype could be rescued by the transgenic expression of normal ameloblastin in Ambn mutant mice. We established and analyzed 5 transgenic lines that expressed ameloblastin from the amelogenin (AmelX) promoter and identified transgenic lines that express virtually no transgene, slightly less than normal (Tg+), somewhat higher than normal (Tg++), and much higher than normal (Tg+++) levels of ameloblastin. All lines expressing detectable levels of ameloblastin at least partially recovered the enamel phenotype. When ameloblastin expression was only somewhat higher than normal, the enamel covering the molars and incisors was of normal thickness, had clearly defined rod and interrod enamel, and held up well in function. We conclude that ameloblastin is essential for dental enamel formation.

Intradermal alpha1-antitrypsin therapy avoids fatal anaphylaxis, prevents type 1 diabetes and reverses hyperglycaemia in the NOD mouse model of the disease

AIMS/HYPOTHESIS

Human alpha1-antitrypsin (hAAT) gene therapy prevents type 1 diabetes in a NOD mouse model of diabetes. However, repeated i.p. injections of hAAT into NOD mice leads to fatal anaphylaxis. The aim of the study was to determine if an alternative route of administration avoids anaphylaxis and allows evaluation of hAAT's potential for diabetes prevention and reversal. We also sought to determine if the addition of granulocyte colony-stimulating factor (G-CSF), augments hAAT's capacity to prevent or reverse disease in the NOD mice.

METHODS

To evaluate hAAT pharmacokinetics, serum hAAT levels were monitored in NOD mice receiving a single dose (2 mg) of hAAT by i.p., s.c. or i.d. injection. For studies of type 1 diabetes prevention and reversal, mice received i.d. hAAT (2 mg/mouse/3 days) for 8 or 10 weeks or hAAT and G-CSF (i.p., 6 microg/day) for 6 weeks. Blood glucose determinations, glucose tolerance testing and insulin tolerance tests were performed.

RESULTS

Both i.p. and s.c. injections resulted in fatal anaphylaxis. The i.d. injection avoided anaphylaxis and i.d. injection of hAAT into 11-week-old NOD mice prevented disease (p = 0.005, AAT vs PBS at 40 weeks of age). Treatment of diabetic NOD mice with hAAT or hAAT plus G-CSF provided long-term (at least 100 days) reversal of diabetes in 50% of treated animals. G-CSF did not enhance the reversal rates of hAAT. Glucose tolerance and insulin levels were normalised in mice with hAAT prevention and reversal.

CONCLUSIONS/INTERPRETATION

Intradermal hAAT prevents and reverses disease in a NOD mouse model of type 1 diabetes without inducing anaphylaxis.

Protective effects of icariin on brain dysfunction induced by lipopolysaccharide in rats

In this study we examined the protective effects of icariin, a flavonol isolated from Herba epimedii, on learning and memory in a rat model with brain inflammation induced by lipopolysaccharide (LPS). Injecting LPS into the lateral ventricle caused rat brain dysfunction, as evidenced by deficits of spatial learning and memory in the Morris water maze. With administration of icariin (30, 60, 120mg/kg body wt./day) for 17 consecutive days, spatial learning and memory abilities were markedly altered. Escape latency and searching distance decreased, and the expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) of brain were significantly reduced as observed by real-time RT-PCR and immunohistochemistry. This study used ibuprofen (40mg/kg body wt./day) as positive control. In conclusion, this study suggested that icariin can improve spatial learning and memory abilities in rats with brain dysfunction induced by LPS, an effect which may be due to decreased expressions of TNF-α, IL-1β and COX-2 in the hippocampus.

Involvement of cysteinyl leukotriene receptors in angiogenesis in rat thoracic aortic rings

Cysteinyl leukotrienes (CysLTs) are potent inflammatory mediators that induce inflammation through the activation of CysLT1 and CysLT2 receptors. It has been reported that inflammatory mediators, such as prostaglandins, play an important role in angiogenesis. However, whether CysLTs and the receptor subtypes are involved in angiogenesis is not clarified. Here, we determined the effects of CysLT receptor agonist leukotriene D4 (LTD4) and antagonists on angiogenesis by rat thoracic aortic ring assay. We found that the microvessel growth in 25% serum-containing cultures was significantly inhibited by the CysLT1 receptor antagonist montelukast (0.1-1 microM), but not by the CysLT2 receptor antagonist BAY cyslt2 (0.1-1 microM). The microvessel growth in serum-free culture was affected neither by montelukast (0.01-1 microM) nor by BAY cyslt2 (0.1-1 microM). Furthermore, LTD4 at 100 nM significantly enhanced the microvessel growth in serum-free culture and LTD4 at 10-100 nM significantly enhanced the microvessel growth in 25% serum-containing cultures. The enhancement was abrogated by both montelukast and BAY cyslt2. Thus, CysLT1 receptors may mediate endogenously regulated microvessel growth in normal culture; whereas the exogenous agonist LTD4 induces angiogenesis through the activation of both CysLT1 and CysLT2 receptors. The CysLT receptor antagonists can be developed as angiogenesis inhibitors.