Growth and stability of rocksalt Zn1-xMgxO epilayers and ZnO/MgO superlattice on MgO (100) substrate by molecular beam epitaxy

Zn1-xMgxO films with x = 0.04-0.50 grown on MgO (100) substrates by molecular beam epitaxy retain the rocksalt (rs) crystal structure and grow epitaxially for x ≥ 0.17. In addition, the rs-ZnO epilayer is observed to be stable up to a thickness of 5 nm and also in a ZnO/MgO superlattice sample. However, a portion of the superlattice has transformed to wurtzite (wz)-structure islands in a self-accommodated manner during growth. The transformation is a combination of a Bain distortion, an in-plane rotation of 14.5°, and a Peierls distortion, resulting in an orientation relationship of (100)rs//(101̄0)wz and 〈011〉rs ∼//〈1̄21̄3〉wz. In such a manner, the volume expansion is only necessary along the growth direction and the in-plane strains can be minimized. A negative pressure generated during the transformation of ZnO stabilizes the MgO into a wurtzite structure.

Neural correlates of working memory training in HIV patients: study protocol for a randomized controlled trial

Background

Potent combined antiretroviral therapy decreased the incidence and severity of HIV-associated neurocognitive disorders (HAND); however, no specific effective pharmacotherapy exists for HAND. Patients with HIV commonly have deficits in working memory and attention, which may negatively impact many other cognitive domains, leading to HAND. Since HAND may lead to loss of independence in activities of daily living and negative emotional well-being, and incur a high economic burden, effective treatments for HAND are urgently needed. This study aims to determine whether adaptive working memory training might improve cognitive functions and neural network efficiency and possibly decrease neuroinflammation. This study also aims to assess whether subjects with the LMX1A-rs4657412 TT(AA) genotype show greater training effects from working memory training than TC(AG) or CC(GG)-carriers.

Methods/Design

60 HIV-infected and 60 seronegative control participants will be randomized to a double-blind active-controlled study, using adaptive versus non-adaptive Cogmed Working Memory Training® (CWMT), 20–25 sessions over 5–8 weeks. Each subject will be assessed with near- and far-transfer cognitive tasks, self-reported mood and executive function questionnaires, and blood-oxygenation level-dependent functional MRI during working memory (n-back) and visual attention (ball tracking) tasks, at baseline, 1-month, and 6-months after CWMT. Furthermore, genotyping for LMX1A-rs4657412 will be performed to identify whether subjects with the TT(AA)-genotype show greater gain or neural efficiency after CWMT than those with other genotypes. Lastly, cerebrospinal fluid will be obtained before and after CWMT to explore changes in levels of inflammatory proteins (cytokines and chemokines) and monoamines.

Discussion

Improving working memory in HIV patients, using CWMT, might slow the progression or delay the onset of HAND. Observation of decreased brain activation or normalized neural networks, using fMRI, after CWMT would lead to a better understanding of how neural networks are modulated by CWMT. Moreover, validating the greater training gain in subjects with the LMX1A-TT(AA) genotype could lead to a personalized approach for future working memory training studies. Demonstrating and understanding the neural correlates of the efficacy of CWMT in HIV patients could lead to a safe adjunctive therapy for HAND, and possibly other brain disorders.

Trial registration

ClinicalTrial.gov, NCT02602418.

Photoconductivities in m-plane and c-plane ZnO epitaxial films grown by chemical vapor deposition on LiGaO2 substrates: a comparative study

Nonpolar (m-plane) and polar (c-plane) ZnO epitaxial films grown by CVD exhibit superior photoconductive performance in different aspects.

G9a Inhibition Induces Autophagic Cell Death via AMPK/mTOR Pathway in Bladder Transitional Cell Carcinoma

G9a has been reported to highly express in bladder transitional cell carcinoma (TCC) and G9a inhibition significantly attenuates cell proliferation, but the underlying mechanism is not fully understood. The present study aimed at examining the potential role of autophagy in the anti-proliferation effect of G9a inhibition on TCC T24 and UMUC-3 cell lines in vitro. We found that both pharmaceutical and genetical G9a inhibition significantly attenuated cell proliferation by MTT assay, Brdu incorporation assay and colony formation assay. G9a inhibition induced autophagy like morphology as determined by transmission electron microscope and LC-3 fluorescence assay. In addition, autophagy flux was induced by G9a inhibition in TCC cells, as determined by p62 turnover assay and LC-3 turnover assay. The autophagy induced positively contributed to the inhibition of cell proliferation because the growth attenuation capacity of G9a inhibition was reversed by autophagy inhibitors 3-MA. Mechanically, AMPK/mTOR pathway was identified to be involved in the regulation of G9a inhibition induced autophagy. Intensively activating mTOR by Rheb overexpression attenuated autophagy and autophagic cell death induced by G9a inhibition. In addition, pre-inhibiting AMPK by Compound C attenuated autophagy together with the anti-proliferation effect induced by G9a inhibition while pre-activating AMPK by AICAR enhanced them. In conclusion, our results indicate that G9a inhibition induces autophagy through activating AMPK/mTOR pathway and the autophagy induced positively contributes to the inhibition of cell proliferation in TCC cells. These findings shed some light on the functional role of G9a in cell metabolism and suggest that G9a might be a therapeutic target in bladder TCC in the future.

Thermomechanical Two-Mode Squeezing in an Ultrahigh-Q Membrane Resonator

We realize a quantum-compatible multimode interaction in an ultrahigh Q mechanical resonator via a reservoir-mediated parametric coupling. We use this interaction to demonstrate nondegenerate parametric amplification and thermomechanical noise squeezing, finding excellent agreement with a theoretical model of this interaction over a large dynamic range. This realization of strong multimode nonlinearities in a mechanical platform compatible with quantum-limited optical detection and cooling makes this a powerful system for nonlinear approaches to quantum metrology, transduction between optical and phononic fields, and the quantum manipulation of phononic degrees of freedom.

Infiltrated pre-adipocytes increase prostate cancer metastasis via modulation of the miR-301a/androgen receptor (AR)/TGF-β1/Smad/MMP9 signals

High fat dietary intake may increase the risk of prostate cancer (PCa). Pre-adipocytes, one of the basic components in the tumor microenvironment (TME), are capable of differentiating into adipose tissues and play key roles to affect PCa progression. Here we found the pre-adipocytes could be recruited more easily to PCa than its surrounding normal prostate tissue. In vitro co-culture system also confirmed PCa has a better capacity than normal prostate to recruit pre-adipocytes. The consequences of recruiting more pre-adipocytes may then increase PCa cell invasion. Mechanism dissection revealed infiltrating pre-adipocytes might function through down-regulation of the androgen receptor (AR) via modulation of miR-301a, and then increase PCa cell invasion via induction of TGF-β1/Smad/MMP9 signals. The mouse model with orthotopically xenografted PCa CWR22Rv1 cells with pre-adipocytes also confirmed that infiltrating pre-adipocytes could increase PCa cell invasion via suppressing AR signaling. Together, our results reveal a new mechanism showing pre-adipocytes in the prostate TME can be recruited to PCa to increase PCa metastasis via modulation of the miR-301a/AR/TGF-β1/Smad/MMP9 signals. Targeting this newly identified signaling may help us to better inhibit PCa metastasis.

A cross-cultural investigation of attachment style, catastrophizing, negative pain beliefs, and symptom severity in irritable bowel syndrome

BACKGROUND

Little information exists regarding whether psychosocial variables in irritable bowel syndrome (IBS) vary by geographic location. Adult attachment is an important psychological concept rooted in childhood relationship experience that has not been previously studied in IBS. Catastrophizing and negative pain beliefs have been described in IBS and may be affected by attachment.

AIMS

In this cross-cultural study, we determined: (i) whether attachment differs between IBS patients and controls, (ii) whether geographic location has a significant effect on attachment style, catastrophizing and negative pain beliefs, and (iii) how all three variables correlate with IBS symptom severity.

METHODS

463 IBS patients, with moderate to severe symptom scores, and 192 healthy controls completed validated questionnaires about attachment, catastrophizing, negative pain beliefs and IBS-SSS in nine locations, USA (New York, Los Angeles), Mexico, Italy (Rome, Bari), Romania, Iran, India, and China.

KEY RESULTS

Attachment anxiety and avoidance scores were significantly higher in IBS patients than in controls (p < 0.001). This was particularly true for the fearful-avoidant attachment category, especially in China and Romania. Path analysis showed that attachment anxiety and avoidance had indirect effects on IBS-SSS through catastrophizing (p < 0.0001) and negative pain beliefs (p = 0.005). All three psychosocial measures varied significantly depending on location.

CONCLUSIONS & INFERENCES

In the IBS population studied, attachment style was significantly different in IBS compared to a control population. Geographic differences in attachment, catastrophizing and negative pain beliefs were documented and their correlation with symptom severity and thus, research of psychosocial variables in IBS should take into account the location of the population studied.

Identification of an SCAR marker related to female phenotype in Idesia polycarpa Maxim

Idesia polycarpa Maxim. is a dioecious species. Because of the lack of morphological and cytological methods available for identifying its sex during the long juvenile stage, the application of molecular markers in sex identification may facilitate sex determination in the seedling stage. The objective of this study was to use sequence-related amplified polymorphism to identify sex-linked markers in I. polycarpa and convert these markers into sequence-characterized amplified region markers, which are much easier to identify. A total of 342 primer combinations were screened and 2770 bands were examined. Only me14/em8 could amplify a specific fragment (210 base pairs) in all female but none in male plants. We analyzed this fragment using GenBank and found that the sequence similarity was 80% to the Populus trichocarpa clone POP006-H09 (sequence ID: gb|AC212923.1|) and that of the deduced amino acid sequence was 73% to the integrase of Mendicago truncatula (sequence ID: gb|ABD28291.1|) and 71% to the predicted retrotransposon integrase-like protein 1-like in Cicer arietinum (sequence ID: ref|XP 004515460.1|) (NCBI database through December 17, 2013). This fragment was converted into a stable and simple sequence-characterized amplified region marker approximately 200 base pairs in length. This marker can be utilized for early sexual identification in I. polycarpa, which will facilitate future breeding programs.

Knockdown of PTTG1 inhibits the growth and invasion of lung adenocarcinoma cells through regulation of TGFB1/SMAD3 signaling

Increased expression of pituitary tumor-transforming gene 1 (PTTG1) is expressed in many tumors and regulates tumor growth and progression. However, the precise function of PTTG1 in the tumorigenesis of lung adenocarcinoma (LAC) is not defined yet. Here, we examined the expression of PTTG1 in human LAC tissues by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was carried out to investigate the effects of lentiviral vector-mediated PTTG1 shRNA (shPTTG1) on cell growth and invasive potential in LAC cell lines (A549 and LETPα-2), assessed by MTT and Transwell assays. As a consequence, we found that the expression of PTTG1 protein was markedly upregulated in LAC tissues compared with the adjacent non-cancerous tissues (ANCT) (54.0% vs. 28.0%, P = 0.008), and was positively associated with the lymphatic invasion of the tumor ( P = 0.01). Moreover, knockdown of PTTG1 expression inhibited tumor proliferation and invasion of LAC cells, companied by the decreased expression of CyclinD1 and MMP-2 and increased expression of p-TGFβ1 and p-SMAD3. Collectively, our findings indicate that high expression of PTTG1 is correlated with the tumor metastasis of LAC patients, and knockdown of PTTG1 suppresses the growth and invasion of LAC cells through upregulation of the TGFβ1/SMAD3 signaling, suggesting that PTTG1 may be a potential target for developing an effective immunotherapeutic strategy for LAC.

Association of the ApoE gene polymorphism and dietary factors with cerebral infarction and circulating lipid concentrations

The aim of this study was to explore the relationship between the ApoE gene polymorphism and dietary factors with stroke and circulating lipid levels in the Chinese population. We selected 580 patients with stroke and 580 age- and gender-matched healthy controls, and examined their ApoE polymorphism genotype using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We also analyzed the relationship between the ApoE gene polymorphism and dietary factors as well as plasma lipid concentrations in this cohort. We detected six ApoE genotypes in the study populations, and determined that the E4 allele was positively associated with cerebral infarction (CI), whereas allele E2 was negatively associated with total cholesterol (TC) and low-density lipoprotein-cholesterol levels. The dietary habits of the subjects with descending order of average total TC and triglyceride levels were: subjects addicted to oily food > subjects addicted to sweets > subjects addicted to smoking > subjects addicted to alcohol > subjects following a vegetarian diet (P < 0.05). Our results demonstrated that the ApoE gene polymorphism was associated with a risk for CI in a Chinese population.

CYP4F2 gene single nucleotide polymorphism is associated with ischemic stroke

The objective of this study was to explore the relationship between CYP4F2 gene polymorphism and ischemic stroke (IS) in the Han Chinese population. We performed a case-control study to genotype four single nucleotide polymorphisms (SNPs) (rs2108622, rs3093100, rs3093105, rs3093135) in the CYF4F2 gene. The genotype and haplotype distributions were compared between the case and control groups. We found that the GG genotype of rs2108622 in the CYP4F2 gene was associated with risk of IS (P = 0.023). Haplotype analysis indicated that the GGGT haplotype comprising rs2108622-rs3093100-rs3093105-rs3093135 was associated with IS, which suggests that the GGGT haplotype may be a risk factor for IS (P = 0.012). CYP4F2 gene polymorphism might increase the risk of IS in the Chinese population.

Epitaxial growth of nonpolar m-plane ZnO epilayers and ZnO/Zn0.55Mg0.45O multiple quantum wells on a LiGaO2 (100) substrate

Nonpolar m-plane ZnO epilayers and ZnO/Zn_0.55Mg_0.45O multiple quantum wells were grown on a LiGaO₂ (100) substrate by molecular beam epitaxy.

The impact of abdominal pain on global measures in patients with chronic idiopathic constipation, before and after treatment with linaclotide: a pooled analysis of two randomised, double-blind, placebo-controlled, phase 3 trials

BACKGROUND

Few clinical trials in chronic idiopathic constipation (CIC) patients have evaluated abdominal symptom severity and whether CIC patients with abdominal symptoms respond similarly to patients with limited abdominal symptoms.

AIMS

To examine abdominal symptom severity and relationships between symptoms and global measures at baseline; compare linaclotide's effect on symptoms in subpopulations with more or less abdominal pain; and assess relationships between symptom improvement and global measures in these two subpopulations.

METHODS

In two phase 3 trials, patients meeting modified Rome II CIC criteria were assigned to linaclotide 145 μg, 290 μg, or placebo once daily. Patients rated abdominal and bowel symptoms daily during 2-week pre-treatment and 12-week treatment periods. Linaclotide's effect on symptoms and global measures [constipation severity, health-related quality of life (HRQOL), treatment satisfaction] and their inter-relationships were assessed in post hoc analyses of abdominal pain subpopulations.

RESULTS

Of 1271 CIC patients, 23%, 32%, and 43% reported moderate-to-severe abdominal pain, discomfort, and bloating, respectively, during baseline. In more-severe abdominal pain patients, abdominal symptoms were more strongly correlated than bowel symptoms with global measures, but in less-severe abdominal pain patients, abdominal and bowel symptoms were similarly correlated with global measures, at baseline and post-treatment. Linaclotide significantly improved all symptoms and global measures in both subpopulations.

CONCLUSIONS

When abdominal pain is present in CIC, abdominal and not bowel symptoms may drive patient assessments of constipation severity, HRQOL, and treatment satisfaction. Linaclotide (145 μg and 290 μg) is an effective treatment for both abdominal and bowel symptoms, even in CIC patients with more severe abdominal pain at baseline. (Clinicaltrials.gov: NCT00765882, NCT00730015).

Novel function discovery with GeneMANIA: a new integrated resource for gene function prediction in Escherichia coli

MOTIVATION

The model bacterium Escherichia coli is among the best studied prokaryotes, yet nearly half of its proteins are still of unknown biological function. This is despite a wealth of available large-scale physical and genetic interaction data. To address this, we extended the GeneMANIA function prediction web application developed for model eukaryotes to support E.coli.

RESULTS

We integrated 48 distinct E.coli functional interaction datasets and used the GeneMANIA algorithm to produce thousands of novel functional predictions and prioritize genes for further functional assays. Our analysis achieved cross-validation performance comparable to that reported for eukaryotic model organisms, and revealed new functions for previously uncharacterized genes in specific bioprocesses, including components required for cell adhesion, iron-sulphur complex assembly and ribosome biogenesis. The GeneMANIA approach for network-based function prediction provides an innovative new tool for probing mechanisms underlying bacterial bioprocesses.

CONTACT

gary.bader@utoronto.ca; mohan.babu@uregina.ca

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Proposed mechanism of antibacterial action of chemically modified apatite for reduced bone infection

Surface-bound silver ions were demonstrated to be responsible for the antibacterial action of silver, silicon-containing hydroxyapatite (Ag,Si-HA). X-ray photoelectron spectroscopy, transmission electron microscopy, and induced coupled plasma spectroscopy results suggested that silver ions in the crystal structure diffused toward the crystal surface of Ag,Si-HA, and interacted with adherent Staphylococcus aureus bacteria, thus damaging the cell wall and inducing leakage of potassium ions. All these steps constitute the mechanism of antibacterial action for Ag,Si-HA. Consequently, Ag,Si-HA gave rise to a 7-log reduction of the adherent bacteria as compared to HA and Si-HA at 168 h. Silicon in Ag,Si-HA helped to mitigate the reduced effect of bone differentiation in Ag-HA as shown in the alkaline phosphatase, type I collagen and osteocalcin results, promoting enhanced biological response, without compromising the antibacterial property. On the whole, Ag,Si-HA containing an optimized content of 0.5 wt % silver and 0.7 wt % silicon provides antibacterial properties and enhanced biological response.

Relationship between progeny growth performance and molecular marker-based genetic distances in Eucommia ulmoides parental genotypes

Progeny performances, variations and combining abilities for growth traits were evaluated in a factorial mating design of Eucommia ulmoides. Three marker systems, sequence-related amplified polymorphism, amplified fragment length polymorphism, and inter-simple sequence repeat, were used to determine genetic distances between parents. Correlations of genetic distances with progeny performances, within-family coefficients of variation and specific-combining abilities were established for height and basal diameter traits. Significant positive correlations were found between progeny performances of growth traits and genetic distances of parents based on sequence-related amplified polymorphism markers or a combination of all 3 marker systems. This revealed that crosses between genetically distant parents produced progenies with excellent growth performances. The lack of correlations between parental genetic distances and within-family coefficients of variation or specific-combining abilities suggested that these characteristics were unpredictable. The results of this study represent a potential criterion to predict progeny performances and choose parents in the breeding program.

Cytokine imbalance in irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder of unknown etiology; although infection and inflammation have recently been considered as important etiologic agents. A recent meta-analysis showed correlations between cytokine [interleukin-10 (IL-10) and tumor necrosis factor (TNF)] gene polymorphisms and IBS; however, it is still unknown whether patients with IBS have different cytokine profiles compared to healthy population.

METHODS

To determine the relationships between serum/plasma levels or mucosal expression of IL-10/TNF-α and IBS, we conducted a systematic review and meta-analysis based on case-control studies retrieved from PubMed and EMBASE search through August 2013. Standardized mean difference (SMD) was generated by using the inverse variance method. Heterogeneity was assessed based on I(2) values.

KEY RESULTS

Serum/plasma levels of TNF-α tended to be higher in IBS vs controls (p = 0.09); this reached significance in IBS subtypes vs controls and in female patients with IBS. However, serum/plasma levels of IL-10 were not significantly different in IBS patients vs controls. Further analysis of serum/plasma IL-10 levels in IBS subtypes did not show any difference; however, analysis based on gender showed a significantly lower serum/plasma IL-10 levels in male patients with IBS vs male controls (p = 0.02). Colonic IL-10 mRNA had a significantly lower expression in IBS vs control (p = 0.001).

CONCLUSIONS & INFERENCES

There is an imbalance of proinflammatory TNF-α, and anti-inflammatory IL-10, cytokines in IBS. Stratifying IBS patients based on cytokine profile may represent an opportunity for personalized treatment of this condition.

ASC-J9 suppresses renal cell carcinoma progression by targeting an androgen receptor-dependent HIF2α/VEGF signaling pathway

Males have a higher incidence of renal cell carcinoma (RCC) than females, but the reason for this gender difference is unknown. Addressing this question, we report the discovery of an androgen receptor (AR)-induced HIF2α/VEGF signal that drives RCC progression. AR attenuation or augmentation in RCC cells altered their proliferation, migration, and invasion in multiple models in vitro and in vivo. Mechanistic investigations revealed that AR targeting inhibited RCC cell migration and invasion by modulating HIF2α/VEGF signals at the level of mRNA and protein expression. Interrupting HIF2α/VEGF signals with inhibitors of either HIF2α or VEGF was sufficient to suppress RCC progression. Similarly, the specific AR degradation enhancer ASC-J9 was sufficient to suppress AR-induced HIF2α/VEGF signaling and RCC progression in multiple models in vitro and in vivo. Taken together, our results revealed a novel role for AR in RCC initiation and progression with implications for novel therapeutic strategies.