In vivo osteoprotegerin gene therapy preventing bone loss induced by periodontitis

OBJECTIVE

The objective of this study was to investigate the effects of osteoprotegerin (OPG) gene therapy on alveolar bone resorption caused by experimental periodontitis in rats, thus forming a foundation for potential clinical applications of OPG gene therapy in the treatment of periodontitis and peri-implantitis.

MATERIAL AND METHODS

To study the effects of OPG on alveolar bone protection, an experimental periodontitis model was used by placing a bacterial plaque retentive silk ligature in the gingival sulcus around the maxillary second molar tooth, injection of Porphyromonas gingivalis and high carbohydrate diet. A total of 30 Sprague-Dawley rats were randomly divided into three groups, with 10 rats in each group: group I (control) was treated with 10 μL normal saline injection; group II with 10 μL mock vector; and group III with 10 μL local OPG gene transfer by transfection with in vitro constructed pcDNA3.1-human OPG (pcDNA3.1-hOPG). A subperiosteal injection was done adjacent to the second molars on days 0, 7, 14 and 21. Four weeks later, all animals were killed and radiographic, histological and immunohistochemical examinations were performed. Statistical analysis included ANOVA and LSD-Bonferroni test.

RESULTS

Group III (OPG gene therapy) had significantly enhanced (p < 0.05) integrated optical density of OPG, had significantly decreased alveolar bone resorption volume and active osteoclast number (p < 0.05) through descriptive histological examination when compared with the other two groups at week 4.

CONCLUSION

Local recombinant OPG plasmid-mediated gene therapy suppresses osteoclastogenesis in vivo and inhibits alveolar bone height reduction caused by experimental periodontitis in rats. OPG gene therapy may be beneficial in preventing progressive periodontal bone loss.

A formyl peptide receptor agonist suppresses inflammation and bone damage in arthritis

BACKGROUND AND PURPOSE

Annexin A1 (AnxA1) is an endogenous anti-inflammatory protein and agonist of the formyl peptide receptor 2 (FPR2). However, the potential for therapeutic FPR ligands to modify immune-mediated disease has been little explored. We investigated the effects of a synthetic FPR agonist on joint disease in the K/BxN model of rheumatoid arthritis (RA) and RA fibroblast-like synoviocytes (FLS).

EXPERIMENTAL APPROACH

Arthritis was induced by injection of K/BxN serum at day 0 and 2 in wild-type (WT) or AnxA1(-/-) mice and clinical and histopathological manifestations measured 8-11 days later. WT mice were given the FPR agonist compound 43 (Cpd43) (6 or 30 mg·kg(-1) i.p.) for 4 days. Effects of AnxA1 and Cpd43 on RANKL-induced osteoclastogenesis were assessed in RAW 264.7 cells and human RA FLS and macrophages.

KEY RESULTS

Treatment with Cpd43 before or after the onset of arthritis reduced clinical disease severity and attenuated synovial TNF-α and osteoclast-associated gene expression. Deletion of AnxA1 in mice exacerbated arthritis severity in the K/BxN model. In vitro, Cpd43 suppressed osteoclastogenesis and NFAT activity elicited by RANKL, and inhibited IL-6 secretion by mouse macrophages. In human RA joint-derived FLS and monocyte-derived macrophages, Cpd43 treatment inhibited IL-6 release, while blocking FPR2 or silencing AnxA1 increased this release.

CONCLUSIONS AND IMPLICATIONS

The FPR agonist Cpd43 reduced osteoclastogenesis and inflammation in a mouse model of RA and exhibited anti-inflammatory effects in relevant human cells. These data suggest that FPR ligands may represent novel therapeutic agents capable of ameliorating inflammation and bone damage in RA.

Characterization of Rice Blast Resistance Gene Pi61(t) in Rice Germplasm

Identification of resistance (R) genes to races of Magnaporthe oryzae in rice (Oryza sativa) germplasm is essential for the development of rice cultivars with long-lasting blast resistance. In the present study, one major quantitative trait locus, qPi93-3, was fine mapped using a recombinant inbred line (RIL), F₈ RIL171, derived from the cross between 'Nipponbare' and '93-11'. RIL171 contained a heterozygous qPi93-3 allele which was found to be resistant against nine U.S. common races-ID1, IA1, IB49, IE1, IA45, IB1, IC17, IB45, and IH1-of M. oryzae. An F₂ mapping population consisting of 2,381 individuals derived from RIL171 was evaluated with a field isolate (race) ARB82 (IA1) of M. oryzae under greenhouse conditions. Disease reaction of a resistant/susceptible ratio of 3:1 was identified with F₂:F₃ families. In total, 12 simple sequence repeat markers spanning qPi93-3 were used for fine mapping. Consequently, qPi93-3 was delimited to 4.2 Mb between RM3246 and RM7102. Three insertion-deletion (InDel) markers located between RM3246 and RM7102, that had previously used to map Pi61(t), showed that qPi93-3 was Pi61(t). The existence of Pi61(t) in 136 rice germplasm lines from the United States Department of Agriculture rice core collection was evaluated using Pi61(t)-specific InDel markers. Pi61(t) was identified as a source of resistance in 5 of the 136 lines. The characterized germplasm will be useful for rice breeders to use for improving blast resistance.

Association of the tumour necrosis factor-α polymorphisms rs361525 and rs1800629 with susceptibility to psoriasis: a meta-analysis

BACKGROUND

Evidence has suggested that tumour necrosis factor (TNF)-α may be involved in the aetiology of psoriasis, but the underlying association of the TNF-α polymorphisms -238G/A (rs361525) and -308G/A (rs1800629) with the risk of psoriasis is still unconfirmed.

AIM

This meta-analysis was performed to determine whether the TNF-α -238G/A and -308G/A polymorphisms are associated with susceptibility to psoriasis.

METHODS

Eligible studies were identified by searching PubMed, EMBASE, CNKI (China National Knowledge Infrastructure), CBM (Chinese biomedical literature database) and WANFANG databases within a range of published years from 1990 to August 2012. The odds ratio (OR) and 95% confidence interval (CI) were used to assess the different associations.

RESULTS

In total, 17 studies with 2847 cases and 2222 controls were found for -238G/A and 20 studies with 2975 cases and 2243 controls for -308G/A. The pooled results showed an overall increased risk of psoriasis for the -238G/A polymorphism (OR = 2.06, 95% CI = 1.45-2.94, P < 0.001 for AA/GA vs. GG) and a reduced psoriasis risk with the -308G/A polymorphism (OR = 0.68, 95% CI = 0.59-0.79, P < 0.001 for AA/GA vs. GG). This association was only present in early-onset psoriasis (OR = 3.68, 95% CI = 2.17-6.24, P < 0.001 for -238G/A; OR = 0.56, 95% CI = 0.43-0.72, P < 0.001 for -308G/A), whereas there was no association (OR = 0.98, 95% CI = 0.56-1.70, P = 0.92 for -238G/A) or a unreliable association (OR = 0.66, 95% CI = 0.46-0.94, P = 0.02 for -308G/A) in late-onset psoriasis.

CONCLUSIONS

This meta-analysis suggests that the TNF-α -238 and -308 promoter polymorphisms may play different roles in conferring susceptibility to psoriasis. Functional and well-designed studies should be conducted to confirm these results.

Huge critical current density and tailored superconducting anisotropy in SmFeAsO₀.₈F₀.₁₅ by low-density columnar-defect incorporation

Iron-based superconductors could be useful for electricity distribution and superconducting magnet applications because of their relatively high critical current densities and upper critical fields. SmFeAsO₀.₈F₀.₁₅ is of particular interest as it has the highest transition temperature among these materials. Here we show that by introducing a low density of correlated nano-scale defects into this material by heavy-ion irradiation, we can increase its critical current density to up to 2 × 10⁷ A cm⁻² at 5 K--the highest ever reported for an iron-based superconductor--without reducing its critical temperature of 50 K. We also observe a notable reduction in the thermodynamic superconducting anisotropy, from 8 to 4 upon irradiation. We develop a model based on anisotropic electron scattering that predicts that the superconducting anisotropy can be tailored via correlated defects in semimetallic, fully gapped type II superconductors.

Zinc-finger BED domain-containing 3 (Zbed3) is a novel secreted protein associated with insulin resistance in humans

OBJECTIVES

Genome-wide association studies (GWAS) have shown that Zbed3 is associated with T2DM. To date, no report has demonstrated a relationship between Zbed3 and insulin resistance in humans, however. The purpose of this study was to determine whether the Zbed3 protein is secreted and identify any associations between Zbed3 and insulin resistance in cross-sectional and interventional studies.

METHODS

We found that Zbed3 protein was secreted in an in vitro secretion study. Plasma Zbed3 levels were determined in an ELISA and were compared with various parameters related to insulin resistance in subjects with NGT, IGT and nT2DM. EHC was performed in healthy subjects. Real-time PCR and Western blotting were used to assess the mRNA and protein expression of Zbed3.

RESULTS

Zbed3 was detected in an analysis of in vitro secretion in both conditioned medium and lysates of HEK-293T cells transfected with an overexpressed vector. In a clinical study, there were significantly higher levels of circulating Zbed3 in IGT and nT2DM relative to NGT. Zbed3 levels were positively correlated with BMI, WHR, FAT%, blood pressure, FBG, TG, HbA1c, FIns and HOMA-IR and inversely correlated with HDL-C. Increasing levels of Zbed3 were independently associated with IGT and T2DM. Zbed3 mRNA and protein in muscle and fat were significantly elevated in both db/db mice and T2DM patients. Moreover, there was a concentration-dependent effect of glucose on Zbed3 release, whereas insulin exhibited an inhibitory effect on Zbed3 levels. Zbed3 suppressed insulin-induced IR and Akt phosphorylation.

CONCLUSIONS

These results suggest that the Zbed3 protein may be a cytokine associated with insulin resistance in humans that is influenced by glucose and insulin levels.

Serum anti-lipocalin 2 IgG is a novel biomarker in the diagnosis of systemic lupus erythematosus

BACKGROUND

Previous work suggests that lipocalin 2 is involved in the pathogenesis of systemic lupus erythematosus (SLE) and that this novel antigen could serve as a high-quality renal biomarker of acute kidney injury in SLE. However, serum lipocalin 2 antibody levels remain unclear. We have therefore undertaken this study to assess the level of serum IgG antibody against lipocalin 2 in different disease states and to evaluate the diagnostic value of this potential biomarker in SLE.

METHODS

Serum levels of anti-lipocalin IgG antibodies were measured by ELISA in 103 SLE patients, 93 rheumatoid arthritis (RA) patients, 29 primary Sjögren's syndrome (pSS) patients, 13 systemic sclerosis (SSc) patients, and 91 healthy controls. Diagnostic properties of anti-lipocalin IgG were determined by receiver-operating characteristic (ROC) curve analysis.

RESULTS

The level of serum anti-lipocalin IgG in patients with SLE was significantly higher than in patients with RA, pSS, SSc, or healthy controls (p < 0.05), effectively distinguishing SLE from other conditions with high sensitivity and specificity (49.5% and 90.7%, respectively). In ROC curve analysis, the area under the curve (AUC) is 0.783, with a 95% confidence interval (CI) extending from 0.729 to 0.839. Anti-lipocalin antibodies were present in 48.1% of anti-Sm-negative SLE patients, and also occurred in SLE patients lacking anti-dsDNA (52%) or anti-nucleosome antibodies (46.3%) antibodies. Finally, SLE patients with positive anti-lipocalin IgG possessed higher levels of IgA and CRP than the negative group (p < 0.05), clearly demonstrating a positive correlation between anti-lipocalin IgG and these laboratory parameters.

CONCLUSIONS

Anti-lipocalin 2 IgG is a promising biomarker for the diagnosis of SLE, particularly when obtained in conjunction with anti-Sm, anti-dsDNA, and anti-nucleosome antibody levels.

Testosterone replacement ameliorates nonalcoholic fatty liver disease in castrated male rats

Nonalcoholic fatty liver disease is common in developed countries and is associated with obesity, metabolic syndrome, and type 2 diabetes. T deficiency is a risk factor for developing these metabolic deficiencies, but its role in hepatic steatosis has not been well studied. We investigated the effects of T on the pathogenesis of hepatic steatosis in rats fed a high-fat diet (HFD). Adult male rats were randomly placed into four groups and treated for 15 weeks: intact rats on regular chow diet (RCD), intact rats on liquid HFD (I+HFD), castrated rats on HFD (C+HFD), and castrated rats with T replacement on HFD (C+HFD+T). Fat contributed 71% energy to the HFD but only 16% of energy to the RCD. Serum T level was undetectable in castrated rats, and T replacement led to 2-fold higher mean serum T levels than in intact rats. C+HFD rats gained less weight but had higher percentage body fat than C+HFD+T. Severe micro- and macrovesicular fat accumulated in hepatocytes with multiple inflammatory foci in the livers of C+HFD. I+HFD and C+HFD+T hepatocytes demonstrated only mild to moderate microvesicular steatosis. T replacement attenuated HFD-induced hepatocyte apoptosis in castrated rats. Serum glucose and insulin levels were not increased with HFD in any group. Immunoblots showed that insulin-regulated proteins were not changed in any group. This study demonstrates that T deficiency may contribute to the severity of hepatic steatosis and T may play a protective role in hepatic steatosis and nonalcoholic fatty liver disease development without insulin resistance.

Irradiation after surgery for breast cancer patients with primary tumours and one to three positive axillary lymph nodes: yes or no?

OBJECTIVE AND METHODS

We retrospectively analyzed clinicopathologic features and survival in breast cancer patients who had T1 or T2 primary tumours and 1-3 histologically involved axillary lymph nodes and who were treated with modified radical mastectomy without adjuvant radiotherapy (rt). We also explored prognosis to find the high- and low-risk groups.

RESULTS

From May 2001 to April 2005, 368 patients treated at Tianjin Tumor Hospital met the study criteria. The 5- and 8-year rates were 7.2% and 10.7% for locoregional recurrence (lrr), 85.1% and 77.7% for disease-free survival (dfs), and 92.8% and 89.3% for overall survival (os). Multivariate Cox regression analysis showed that age, tumour size, estrogen receptor (er) status, and lymphovascular invasion (lvi) were independent prognostic factors for lrr and dfs. Based on 4 patient-related factors that indicate poor prognosis (age < 40 years, tumour > 3 cm, er negativity, and lvi), the high-risk group (patients with 3 or 4 factors, accounting for 12.5% of the cohort) had 5- and 8-year rates of 24.3% and 36.9% for lrr, 57.2% and 39.2% for dfs, and 74.8% and 43.8% for os compared with 5.0% and 7.1% for lrr, 88.9% and 83.1% for dfs, 91.6% and 83.4% for os in the low-risk group (patients with 0-2 factors, accounting for 87.5% of the cohort; p < 0.001).

CONCLUSIONS

Our study identified several risk factors that correlated independently with a greater incidence of lrr and distant metastasis in patients with T1 and T2 breast cancer and 1-3 positive nodes. Patients with 0-2 risk factors may not be likely to benefit from post-mastectomy rt, but patients with 3-4 risk factors may need rt to optimize locoregional control and improve survival.

Death-associated protein-3, DAP-3, correlates with preoperative chemotherapy effectiveness and prognosis of gastric cancer patients following perioperative chemotherapy and radical gastrectomy

Background:

DAP3 is a member of the death-associated protein (DAP) family and is characterised by proapoptotic function. It is involved in both exogenous and endogenous apoptotic pathways. In our previous studies, apoptotic level was found to be correlated with the effectiveness of preoperative chemotherapy. The effectiveness of preoperative chemotherapy was also associated with the overall effectiveness of the combined therapy and prognosis. The present study aimed to investigate the role of DAP3 in the evaluation of preoperative chemotherapy effectiveness and its ability to predict prognosis in gastric cancer.

Methods:

Quantitative PCR and immunohistochemistry staining were performed in 87 patients who received combined therapy. Knockdown of DAP3 was conducted in gastric cancer cell lines to investigate its impact on cell growth, migration, adhesion and invasion. Tolerance to chemotherapy agents was determined by assessing apoptosis and caspase-3.

Results:

Higher DAP3 expression in gastric tumours was correlated with better prognosis. Knockdown of DAP3 expression promoted cell migration and enhanced resistance to chemotherapy by inhibiting apoptosis.

Conclusion:

DAP3 is a potential molecular marker for response to preoperative chemotherapy and for predicting prognosis in gastric cancer patients treated with neoadjuvant chemotherapy and gastrectomy.

Tracking algorithms for multiagent systems

This paper is devoted to the consensus tracking issue on multiagent systems. Instead of enabling the networked agents to reach an agreement asymptotically as the time tends to infinity, the consensus tracking between agents is considered to be derived on a finite time interval as accurately as possible. We thus propose a learning algorithm with a gain operator to be determined. If the gain operator is designed in the form of a polynomial expression, a necessary and sufficient condition is obtained for the networked agents to accomplish the consensus tracking objective, regardless of the relative degree of the system model of agents. Moreover, the H∞ analysis approach is introduced to help establish conditions in terms of linear matrix inequalities (LMIs) such that the resulting processes of the presented learning algorithm can be guaranteed to monotonically converge in an iterative manner. The established LMI conditions can also enable the iterative learning processes to converge with an exponentially fast speed. In addition, we extend the learning algorithm to address the relative formation problem for multiagent systems. Numerical simulations are performed to demonstrate the effectiveness of learning algorithms in achieving both consensus tracking and relative formation objectives for the networked agents.

Sphingosine-1-phosphate is a possible fibrogenic factor in gluteal muscle fibrosis

Gluteal muscle contracture (GMC) is a chronic fibrotic disease of gluteal muscles due to multiple etiologies. The main pathologic process is characterized by proliferation of fibroblasts and excessive accumulation of collagen in the extracellular matrix of the muscle. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid and has been reported to be associated with various fibrotic diseases. However, the role of S1P in GMC remains unknown. Here in this article, High-performance liquid chromatography and immunohistochemistry were applied to evaluate S1P localization and expression in clinical samples from patients with GMC, Quantitative real time PCR, Western blot, and enzyme-linked immunosorbent assay were used to explore the link between transforming growth factor-beta1 (TGF-beta1), plasminogen activator inhibitor-1 (PAI-1) and S1P. The results showed that S1P was enhanced in contraction band (CB) tissues. Studies using the cell proliferation and transformation assay indicated that exogenous S1P stimulated CB fibroblast proliferation in a time-dependent manner and in higher concentration also in a dose-dependent manner. Furthermore, we demonstrated that S1P not only promoted collagen type I production, but also up-regulated mRNA and protein expression of transforming growth factor-beta1 and plasminogen activator inhibitor-1. These findings suggest that S1P may regulate increased synthesis of collagen and other fibrogenic factors, and significantly contributes to the process of gluteal muscle scarring in patients with GMC.

Toll-like receptor alterations in myelodysplastic syndrome

Recent studies have implicated the innate immunity system in the pathogenesis of myelodysplastic syndromes (MDS). Toll-like receptor (TLR) genes encode key innate immunity signal initiators. We recently identified multiple genes, known to be regulated by TLRs, to be overexpressed in MDS bone marrow (BM) CD34+ cells, and hypothesized that TLR signaling is abnormally activated in MDS. We analyzed a large cohort of MDS cases and identified TLR1, TLR2 and TLR6 to be significantly overexpressed in MDS BM CD34+ cells. Deep sequencing followed by Sanger resequencing of TLR1, TLR2, TLR4 and TLR6 genes uncovered a recurrent genetic variant, TLR2-F217S, in 11% of 149 patients. Functionally, TLR2-F217S results in enhanced activation of downstream signaling including NF-κB activity after TLR2 agonist treatment. In cultured primary BM CD34+ cells of normal donors, TLR2 agonists induced histone demethylase JMJD3 and interleukin-8 gene expression. Inhibition of TLR2 in BM CD34+ cells from patients with lower-risk MDS using short hairpin RNA resulted in increased erythroid colony formation. Finally, RNA expression levels of TLR2 and TLR6, as well as presence of TLR2-F217S, are associated with distinct prognosis and clinical characteristics. These findings indicate that TLR2-centered signaling is deregulated in MDS, and that its targeting may have potential therapeutic benefit in MDS.

The cytoprotective peptide humanin is induced and neutralizes Bax after pro-apoptotic stress in the rat testis

We have previously demonstrated that the mitochondria-derived cytoprotective peptide humanin (HN), when administered intratesticularly to rats, rescues germ cells from apoptosis secondary to testicular stress of hormonal deprivation induced by gonadotropin-releasing hormone antagonist (GnRH-A). To decipher the cellular mechanisms of HN action in the amelioration of GnRH-A-induced germ cell apoptosis, adult male rats received the following treatments for 5 days: (i) daily intratesticular (IT) injections with saline (control); (ii) a single subcutaneous injection of GnRH-A on Day 1 and daily IT injection of saline; (iii) daily IT injection of synthetic HN; and (iv) GnRH-A injection on Day 1 and daily IT injection of HN (GnRH-A+HN). HN alone had no effect on germ cell apoptosis. GnRH-A increased germ cell apoptosis and BAX in the testicular mitochondrial fractions. Synthetic HN decreased germ cell apoptosis induced by GnRH-A and BAX in the mitochondria. We deduced that the cytoprotective action of synthetic HN on GnRH-A-induced germ cell apoptosis was mediated by attenuating p38 mitogen-activated protein kinase activity and increasing STAT3 phosphorylation. The effect of synthetic HN on the expression of endogenous rat HN in the testis was studied using rat HN specific antibody. GnRH-A treatment increased, but concomitant treatment with synthetic HN reduced endogenous rat HN expression in both cytosolic and mitochondrial fractions in testis. Co-immunoprecipitation experiments demonstrated that the increased rat HN was physically associated with BAX in the cytosolic testicular fractions after GnRH-A treatment. Double-immunofluorescence staining confirmed the co-localization of BAX and rat HN in the cytoplasm of Leydig cells and spermatocytes after GnRH-A treatment. We conclude that the cytoprotective effect of exogenously administered synthetic HN is mediated by interactions of endogenous rat HN with BAX in the cytoplasm preventing the entry of BAX to the mitochondria to govern the fate of germ cell survival or death during pro-apoptotic stress to the testis in rats.

Serum level of soluble fibrinogen-like protein 2 in renal allograft recipients with acute rejection: a preliminary study

BACKGROUND

Soluble fibrinogen-like protein 2 (sfgl2), which is mainly secreted by T cells, is a novel effector of regulatory T cells with immunosuppressive functions. The aim of this study was to investigate serum levels of sfgl2 among renal allograft recipients.

METHODS

From November 2010 to August 2011 we retrospectively divided 47 renal allograft recipients into an acute rejection (n = 19) versus a stable group (n = 28) according to allograft biopsy results, using the Banff 2007 classification. The acute rejection group was subdivided into grade I (n = 8) versus grade II T-cell-mediated (n = 6) or antibody-mediated rejection episodes (n = 5). Peripheral blood samples were collected at the time of biopsy. Fourteen healthy volunteers were included as normal group controls. Serum levels of sfgl2 were analyzed by enzyme-linked immunosorbent assay.

RESULTS

Serum levels of sfgl2 were increased among renal allograft recipients suffering from biopsy-proven acute rejection episodes (61.91 ± 45.68 ng/mL), versus those with stable allografts (38.59 ± 19.92 ng/mL, P < .05) or healthy volunteers (29.10 ± 18.08 ng/mL, P < .05). The sfgl2 level was significantly higher among patients with antibody-mediated (118.48 ± 55.54 ng/mL) than T-cell-mediated acute rejection episodes (41.71 ± 16.44 ng/mL, P < .01). Serum sfgl2 levels were remarkably elevated in patients with grade II (51.87 ± 19.13 ng/mL) versus grade I T-cell-mediated rejection (34.10 ± 9.26 ng/mL, P < .05).

CONCLUSIONS

Serum sfgl2 levels were increased among renal allograft recipients with acute rejection episodes to an extent dependent upon the pathological type and severity of the response.

Confirming QTLs and Finding Additional Loci Responsible for Resistance to Rice Sheath Blight Disease

Rice sheath blight disease, caused by Rhizoctonia solani AG1-1A, is one of the most destructive rice diseases worldwide. Utilization of host resistance is the most economical and environmentally sound strategy in managing sheath blight (ShB). Ten ShB quantitative trait loci (QTLs) were previously mapped in a Lemont × Jasmine 85 recombinant inbred line (LJRIL) population using greenhouse inoculation methods at an early vegetative stage. However, confirmation of ShB-resistant QTLs under field conditions is critical for their utilization in marker-assisted selection (MAS) for improving ShB resistance in new cultivars. In the present study, we evaluated ShB resistance using 216 LJRILs under field conditions in Arkansas, Texas, and Louisiana during 2008 and 2009. We confirmed the presence of the major ShB-QTL qShB9-2 based on the field data and also identified one new ShB-QTL between markers RM221 and RM112 on chromosome 2 across all three locations. Based on the field verification of ShB evaluations, the microchamber and mist-chamber assays were simple, effective, and reliable methods to identify major ShB-QTLs like qShB9-2 in the greenhouse at early vegetative stages. The markers RM215 and RM245 were found to be closely linked to qShB9-2 in greenhouse and field assays, indicating that they will be useful for improving ShB resistance in rice breeding programs using MAS.

Catalyst-free growth of millimeter-long topological insulator Bi₂Se₃ nanoribbons and the observation of the π-Berry phase

We report the growth of single-crystalline Bi(2)Se(3) nanoribbons with lengths up to several millimeters via a catalyst-free physical vapor deposition method. Scanning transmission electron microscopy analysis reveals that the nanoribbons grow along the (112̅0) direction. We obtain a detailed characterization of the electronic structure of the Bi(2)Se(3) nanoribbons from measurements of Shubnikov-de Haas (SdH) quantum oscillations. Angular dependent magneto-transport measurements reveal a dominant two-dimensional contribution originating from surface states. The catalyst-free synthesis yields high-purity nanocrystals enabling the observation of a large number of SdH oscillation periods and allowing for an accurate determination of the π-Berry phase, one of the key features of Dirac fermions in topological insulators. The long-length nanoribbons open the possibility for fabricating multiple nanoelectronic devices on a single nanoribbon.

Biclustering of linear patterns in gene expression data

Identifying a bicluster, or submatrix of a gene expression dataset wherein the genes express similar behavior over the columns, is useful for discovering novel functional gene interactions. In this article, we introduce a new algorithm for finding biClusters with Linear Patterns (CLiP). Instead of solely maximizing Pearson correlation, we introduce a fitness function that also considers the correlation of complementary genes and conditions. This eliminates the need for a priori determination of the bicluster size. We employ both greedy search and the genetic algorithm in optimization, incorporating resampling for more robust discovery. When applied to both real and simulation datasets, our results show that CLiP is superior to existing methods. In analyzing RNA-seq fly and worm time-course data from modENCODE, we uncover a set of similarly expressed genes suggesting maternal dependence. Supplementary Material is available online (at www.liebertonline.com/cmb).

Condom use, intervention service utilization and HIV knowledge among female sex workers in China: results of three consecutive cross-sectional surveys in Shandong Province with historically low HIV prevalence

Heterosexual transmission of HIV through contact with female sex workers (FSWs) is a growing concern for the HIV/AIDS epidemic in China. Using consecutive cross-sectional surveys, we examined the prevalence of HIV and sexually transmitted infections (STIs), risk behaviours, HIV knowledge and the utilization of intervention services among FSWs in Shandong Province. Of 3460 participants, half reported ever having STI-related symptoms, 57.8% had ≥7 clients in the last week, half reported inconsistent use of condoms with clients and 11.2% reported ever using illicit drugs. Consistent use of condoms with clients was associated with higher education, being 20-24 years of age, being recruited from hotels, having ever received free condoms and was inversely associated with STI-related symptoms. HIV-related knowledge was associated with higher education, ever testing for HIV and inversely associated with self-reported STI-related symptoms. The low rates of condom use, high number and frequent turnover of clients, high prevalence of self-reported STIs and drug use highlight the urgency for more effective intervention in these FSWs.

Expression of putative stem marker nestin and CD133 in advanced serous ovarian cancer

It is hypothesized that "cancer stem cells" are responsible for the resistance to chemotherapy of cancer cells in ovarian cancers. The objective of the studies was to explore if the stem cell biomarkers could be used to predict the tumor chemotherapy-resistance in serous ovarian cancer patients. Expression of two putative stem cell markers CD133 and nestin, and vascular epithelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) were detected in 123 cases of advanced serous ovarian cancer specimens by immunohistochemistry. To estimate intra-tumoral microvessel density (MVD), CD34 immunostaining was also performed. CD133 and nestin were defined to be positive in 35.0% and 32.5% of the serous ovarian carcinoma tissues, respectively. It was observed that overexpression of nestin but not CD133 was associated with the cisplatin-based chemotherapy resistance and shorter overall survival of the patients, and nestin was found to be an independent prognostic factor. Moreover, positive nestin expression also correlated to increased expression of EGFR and VEGF, and elevated MVD in tumors. The results of this study suggest that serous ovarian cancers with high expression level of nestin represent an aggressive malignant phenotype associated with poor prognosis, and treatment targeted the nestin positive cancer cells might be a promising therapeutic strategy for this subgroups.

Identification of the rice blast resistance gene Pib in the National Small Grains Collection

The Pib gene in rice confers resistance to a wide range of races of the rice blast pathogen, Magnaporthe oryzae, including race IE1k that overcomes Pita, another broad-spectrum resistance gene. In this study, the presence of Pib was determined in 164 rice germplasm accessions from a core subset of the National Small Grains Collection utilizing DNA markers and pathogenicity assays. The presence of Pib was evaluated with two simple sequence repeat (SSR) markers and a dominant marker (Pib-dom) derived from the Pib gene sequence. Pathogenicity assays using two avirulent races (IE1k and IB1) and a virulent race (IB54) were performed to verify the resistance responses of accessions. Of the 164 accessions evaluated, 109 contained the Pib gene as determined using both SSR markers and pathogenicity assays, albeit different haplotypes were detected. The remaining 52 germplasm accessions were different in their responses to the blast races IB54, IE1k, and IB1, thus indicating the presence of R gene(s) other than Pib. The accessions characterized in this study could be used for marker-assisted breeding to improve blast resistance in indica and japonica cultivars worldwide.

Akt1 inhibits homologous recombination in Brca1-deficient cells by blocking the Chk1-Rad51 pathway

Brca1 deficiency leads to the development of breast cancer. We previously found that Brca1 deficiency activates the Akt oncogenic pathway. Reduced expression of Brca1 was highly correlated with increased activated Akt in human breast cancer samples. Furthermore, activation of Akt1 was involved in Brca1-deficiency-mediated tumorigenesis in mice. Defective homologous recombination (HR) is thought to be a major contributor to tumorigenesis in Brca1 deficiency. Here, we show that Akt1 promotes chromosome instability in Brca1-deficent cells. DNA breaks in Brca1-deficent cells are aberrantly joined into complex chromosome rearrangements by a process dependent on Akt1. Depletion of Akt1 increases HR in Brca1-mutant cells, which is rescued by expression of wild-type, but not mutant Akt1 with deletion of Brca1-binding domain. Mechanistically, activated Akt1 in Brca1-deficient cells impairs Chk1 nuclear localization and subsequently disrupts interaction of Chk1 and Rad51 leading to HR defects. Our results indicate that Brca1 deficiency might activate Akt1 contributing to tumorigenesis through regulation of the Chk1-Rad51 signaling.

Heat treatments to kill Pseudomonas syringae pv actinidiae on contaminated pollen

Various combinations of heat time and relative humidity (RH) were tested for their ability to kill Pseudomonas syringae pv actinidiae (Psa) the cause of kiwifruit canker on freshly harvested anthers artificially contaminated with this bacterium Pollen viability and Psa survival were tested after treatment Although short durations at high temperatures and high RH did kill Psa these treatments were also lethal to pollen When RH was reduced the time before pollen viability was lost increased but Psa survival was also enhanced The most promising treatment was 35C at a RH of 50 or less at which pollen viability was not affected even after 20 h but Psa did not survive when applied at 106 cfu/ml Modelling suggests that extending the time of treatment would kill higher concentrations of Psa The mechanism for Psa death at 35C is probably by a combination of heat and desiccation