Hexagonally deformed Fermi surface of the 3D topological insulator Bi2Se3

A hexagonal deformation of the Fermi surface of Bi2Se3 has been for the first time observed by angle-resolved photoemission spectroscopy. This is in contrast to the general belief that Bi2Se3 possesses an ideal Dirac cone. The hexagonal shape is found to disappear near the Dirac node, which would protect the surface state electrons from backscattering. It is also demonstrated that the Fermi energy of naturally electron-doped Bi2Se3 can be tuned by 1% Mg doping in order to realize the quantum topological transport.

Structural and phase changes in amorphous solid water films revealed by positron beam spectroscopy

The evolution and annealing of pores in, and the crystallization of, vapor-deposited films of amorphous solid water have been studied by using variable-energy positron annihilation spectroscopy for temperatures in the range 50-150 K. Both positron and positronium annihilation provide insight to the nature of the grown-in pores and their evolution with temperature. Crystallization of the films was observed at just below 140 K, in agreement with earlier studies, with the topmost 80 nm undergoing a transition consistent with crystallization at 90-100 K.

Regulatory T cells are critical to tolerance induction in presensitized mouse transplant recipients through targeting memory T cells

Memory T cells are a significant barrier to induction of transplant tolerance. However, reliable means to target alloreactive memory T cells have remained elusive. In this study, presensitization of BALB/c mice with C57BL/6 skin grafts generated a large number of OX40(+)CD44(hi)effector/memory T cells and resulted in rapid rejection of donor heart allografts. Recognizing that anti-OX40L monoclonal antibody (mAb) (alpha-OX40L) monotherapy prolonged graft survival through inhibition and apoptosis of memory T cells in presensitized recipients, alpha-OX40L was added to the combined treatment protocol of LF15-0195 (LF) and anti-CD45RB (alpha-CD45RB) mAb-a protocol that induced heart allograft tolerance in non-presensitized recipients but failed to induce tolerance in presensitized recipients. Interestingly, this triple therapy restored donor-specific heart allograft tolerance in our presensitized model that was associated with induction of tolerogenic dendritic cells and CD4(+)CD25(+)Foxp3(+) T regulatory cells (Tregs). Of note, CD25(+) T cell depletion in triple therapy recipients prevented establishment of allograft tolerance. In addition, adoptive transfer of donor-primed effector/memory T cells into tolerant recipients markedly reduced levels of Tregs and broke tolerance. Our findings indicated that targeting memory T cells, by blocking OX40 costimulation in presensitized recipients was very important to expansion of Tregs, which proved critical to development of tolerance.

The European disorder of sex development registry: a virtual research environment

Disorders of sex development (DSD) are a rare group of conditions which require further research. Effective research into understanding the aetiology, as well as long-term outcome of these rare conditions, requires multicentre collaboration often across national boundaries. The EU-funded EuroDSD programme (www.eurodsd.eu) is one such collaboration involving clinical centres and clinical and genetic experts across Europe. At the heart of the EuroDSD collaboration is a European DSD registry and a targeted virtual research environment (VRE) that supports the sharing of DSD data. Security, ethics and information governance are cornerstones of this infrastructure. This paper describes the infrastructure that has been developed, the inherent challenges in security, availability and dependability that must be overcome for the enterprise to succeed and provides a sample of the data that are stored in the registry along with a summary analysis of the current data sets.

Electrode displacement strain imaging of thermally-ablated liver tissue in an in vivo animal model

PURPOSE

Percutaneous thermal ablation is increasingly being used to destroy hepatic tumors in situ. The success of ablative techniques is highly dependent on adequate ablation zone monitoring, and ultrasound-based strain imaging could become a convenient and cost-effective means to delineate ablation zone boundaries. This study investigates in vivo electrode displacement-based strain imaging for monitoring hepatic ablation procedures that are difficult to perform with conventional elastography.

METHODS

a In our method, minute displacements (less than a millimeter) are applied to the unconstrained end of the ablation electrode, resulting in localized tissue deformation within the ablation zone that provides the mechanical stimuli required for strain imaging. This article presents electrode displacement strain images of radiofrequency ablation zones created in porcine liver in vivo (n = 13).

RESULTS

Cross-sectional area measurements from strain images of these ablation zones were obtained using manual and automated segmentation. Area measurements from strain images were highly correlated with areas measured on histopathology images, quantitated using linear regression (R = 0.894, P < 0.001 and R = 0.828, P < 0.001, respectively).

CONCLUSIONS

This study further demonstrates that electrode displacement elastography is capable of providing high-contrast images using widely available commercial ultrasound systems which may potentially be used to assess the extent of thermal ablation zones.

Homeobox gene IRX1 is a tumor suppressor gene in gastric carcinoma

The IRX1 tumor suppressor gene is located on 5p15.33, a cancer susceptibility locus. Loss of heterozygosity of 5p15.33 in gastric cancer was identified in our previous work. In this study, we analyzed the molecular features and function of IRX1. We found that IRX1 expression was lost or reduced in gastric cancer. However, no mutations were identified in IRX1-encoding regions. IRX1 transcription was suppressed by hypermethylation, and the expression of IRX1 mRNA was partially restored in gastric cancer cells after 5-Aza-dC treatment. Restoring IRX1 expression in SGC-7901 and NCI-N87 gastric cancer cells inhibited growth, invasion and tumorigenesis in vitro and in vivo. We identified a number of target genes by global microarray analysis after IRX1 transfection combined with real-time PCR and chromatin immunoprecipitation assay. BDKRB2, an angiogenesis-related gene, HIST2H2BE and FGF7, cell proliferation and invasion-related genes, were identified as direct IRX1 target genes. The hypermethylation of IRX1 was not only detected in primary gastric cancer tissues but also in the peripheral blood of gastric cancer patients, suggesting IRX1 could potentially serve as a biomarker for gastric cancer.

Template engineering of Co-doped BaFe2As2 single-crystal thin films

Understanding new superconductors requires high-quality epitaxial thin films to explore intrinsic electromagnetic properties and evaluate device applications. So far, superconducting properties of ferropnictide thin films seem compromised by imperfect epitaxial growth and poor connectivity of the superconducting phase. Here we report new template engineering using single-crystal intermediate layers of (001) SrTiO(3) and BaTiO(3) grown on various perovskite substrates that enables genuine epitaxial films of Co-doped BaFe(2)As(2) with a high transition temperature (T(c,rho=0) of 21.5 K, where rho=resistivity), a small transition width (DeltaT(c)=1.3 K), a superior critical current density J(c) of 4.5 MA cm(-2) (4.2 K) and strong c-axis flux pinning. Implementing SrTiO(3) or BaTiO(3) templates to match the alkaline-earth layer in the Ba-122 with the alkaline-earth/oxygen layer in the templates opens new avenues for epitaxial growth of ferropnictides on multifunctional single-crystal substrates. Beyond superconductors, it provides a framework for growing heteroepitaxial intermetallic compounds on various substrates by matching interfacial layers between templates and thin-film overlayers.

Association between Mycobacterium avium subspecies paratuberculosis infection and milk production in two California dairies

The association between Mycobacterium avium ssp. paratuberculosis (MAP) and milk production was estimated on 2 California dairies using longitudinal data from 5,926 cows. Both study herds had moderate MAP seroprevalence, housed cows in freestalls, and had Johne's disease control programs. Cow MAP status was determined using both serum ELISA and fecal culture results from cows tested at dry-off and from whole-herd tests. Potential confounders were evaluated based on a causal diagram. Mixed models with 2 functions (splines) for days in milk (DIM) representing milk production pre- and postpeak used in similar studies were further modified to use each cow's observed DIM at peak and lactation length. Cows that were seropositive produced 2.5kg less 4% fat-corrected milk (FCM) per day than their seronegative herdmates. In addition, cows that were fecal-culture positive by liquid culture and confirmed by PCR produced 2.2kg less 4% FCM per day than their fecal-culture negative herdmates. The decrease in milk production in MAP test-positive compared with test-negative cows started in the second lactation. A switch in MAP status in either ELISA or fecal culture results from positive to negative had no significant association with milk production. Modified DIM functions that used the observed DIM at peak had better model fit than another function that assumed a fixed peak at 60 DIM. Cows that tested positive for MAP on serum ELISA or fecal culture produced less milk than cows that tested negative, and the association between MAP and milk production was not confounded by mastitis, elevated somatic cell counts, or uterine or metabolic cow conditions.

Early exposure of high-dose interleukin-4 to tumor stroma reverses myeloid cell-mediated T-cell suppression

Myeloid-derived suppressor cells (MDSCs) inhibit T-cell activity and promote tumor growth in tumor-bearing hosts. We sought to determine how to prevent the generation of these cells and modulate anti-tumor immunity at different times during tumor growth. Interleukin-4 (IL-4), a cytokine closely associated with the differentiation of myeloid cells, was expressed locally at the tumor site with its dose and expression time tightly regulated by a tet-off system. Early exposure of high-dose IL-4 to the tumor stromal cells effectively prevented the generation of myeloid suppressor cells and led to a T-cell-mediated tumor rejection. However, IL-4 had no effect a few days after tumor growth, when myeloid suppressor cells had been generated and T cells were tolerized. Importantly, coinoculation of IL-4 receptor (IL-4R)-deficient tumor cells with IL-4R competent, but not IL-4R-deficient myeloid cells led to IL-4-mediated tumor regression in IL-4R-deficient mice, indicating that IL-4 acts directly on myeloid cells. These results show a novel way to prevent T cells from MDSC-induced suppression, with important indications for cancer therapy.

AKT1 polymorphisms are associated with tuberculosis in the Chinese population

AKT1, a serine/threonine kinase, plays a critical role in the controlling of intracellular growth of Mycobacterium tuberculosis. In this study, we investigated whether polymorphisms in AKT1 affect susceptibility to tuberculosis (TB). Two single nucleotide polymorphisms of AKT1, IVS3+18C>T and +726G>A were genotyped in Chinese patients with pulmonary TB by polymerase chain reaction-restriction fragment length polymorphism. Patients with pulmonary TB had significantly lower IVS3+18 C/C genotype and higher C/T genotype compared with age-, gender- and ethnically matched controls (P < 0.05). The T-A haplotype frequency was significantly higher in patients than in controls (P < 0.05). In conclusion, our result indicates that AKT1 polymorphisms are associated with susceptibility to pulmonary TB.

MicroRNA-25 functions in regulation of pigmentation by targeting the transcription factor MITF in Alpaca (Lama pacos) skin melanocytes

Although the influence of endocrine factors is well established, the molecular and cellular mechanisms controlling coat color are not completely understood. A major mechanism for post-transcriptional regulation of gene expression is through the action of microRNAs (miRNAs), which anneal to the 3' untranslated region of mRNAs in a sequence-specific fashion and either block translation or promote transcript degradation. In this study, we investigated the expression of miRNAs in the skin of alpacas with brown vs white coat color using a microarray screen; identified potential mRNA targets for identified miRNAs among coat color genes; and subsequently determined the ability of a specific, differentially expressed miRNA (miR-25) to suppress expression of micropthalmia-associated transcription factor (MITF), a predicted miR-25 target gene that regulates genes linked to coat color. Expression of 10 different miRNA species in the skin of alpacas with brown vs white coat color was identified from microarray screens. Of the 10 alpaca skin miRNAs identified, predicted binding sites in the 3' untranslated region of RNAs encoding for known genes linked to coat color were primarily for miR-25, but sites were also identified for miR-129 and miR-377. Potential miR-25 binding sites were present in transcripts encoding for 11 coat color genes, including MITF. An inverse relationship between transcript abundance for MITF and miR-25 was observed in skin samples collected from alpacas with white vs brown coat color. Furthermore, overexpression of miR-25 in cultured melanocytes reduced MITF mRNA and protein abundance and corresponding mRNA abundance for the MITF-regulated enzymes tyrosinase and tyrosinase-related protein 1. Results support a novel functional role for miRNA-25 in the regulation of gene expression linked to coat color.

Ruscogenin glycoside (Lm-3) isolated from Liriope muscari improves liver injury by dysfunctioning liver-infiltrating lymphocytes

The effects of ruscogenin 1-O-[β-d-glucopyranosyl(1 → 2)] [β-d-xylopyranosyl(1 → 3)]-β-d-fucopyranoside (Lm-3) and its aglycone, ruscogenin, on liver injury induced in mice by delayed-type hypersensitivity to picryl chloride have been investigated. Lm-3 and ruscogenin significantly decreased liver injury when given during the effector phase of the delayed-type hypersensitivity reaction. The pretreatment of nonparenchymal cells, but not hepatocytes, with Lm-3 or ruscogenin in-vitro caused a concentration- and time-dependent inhibition against the damage. Lm-3 showed a stronger inhibition against the damage than ruscogenin (IC50: Lm-3 6.3 times 10−10  m, ruscogenin 3.9 times 10−7  m). However, neither Lm-3 nor ruscogenin blocked the hepatotoxic potential of CCl4, when used to pretreat hepatocytes. Moreover, Lm-3 and ruscogenin inhibited concanavalin A-induced lymphocyte proliferation only at high concentrations. These results suggested that Lm-3 and ruscogenin improved the immunological liver injury by selectively causing dysfunction of the liver-infiltrating cells rather than by protecting hepatocyte membranes. Such characteristics would be significant for treating immunologically related liver diseases as well as for developing new drugs.

Effect of timing, dose and interstitial versus nanoparticle delivery of tumor necrosis factor alpha in combinatorial adjuvant cryosurgery treatment of ELT-3 uterine fibroid tumor

Cryosurgery has shown potential as a minimally invasive technology for tumor treatment. However, incomplete destruction followed by tumor recurrence after cryosurgery is a common drawback. This study characterizes several variables in the cryoadjuvant TNF-alpha enhancement of conservative cryosurgery (i.e. freezing to the visible edge) of ELT-3 (uterine leiomyoma) tumor in a female nude mouse model. The variables include pretreatment time, mode of TNF-alpha delivery (native vs. CYT-6091, a PEGylated 33 nm colloidal gold core nanoparticle) and dose of TNF-alpha. Survival and tumor growth delay were measured up to 30 days and showed: 1) pretreatment with TNF-alpha required 4 hours incubation prior to cryosurgery to produce a tumor growth delay over cryosurgery alone, and 2) CYT-6091 reduced the toxicity of TNF-alpha administration over intratumoral or peritumoral injection of native TNF-alpha. Taken together, 5 microgram TNF-alpha delivered by the nanodrug CYT-6091 4 hours prior to cryosurgery yielded a dramatic reduction in tumor growth over cryosurgery alone and in some cases even total remission of the tumor. However, some toxicity at higher doses (i.e. 5 micrograms) with CYT-6091 was noted compared to previous work in prostate (LNCaP) cancer grown in a male nude mouse. Potential reasons for this, including sex and weight of the animals are discussed. Further opportunities to optimize the TNF-alpha enhanced cryosurgical response of this tumor include dosing between 2 - 5 microgram at 4 hours prior to cryosurgery, and freezing beyond the visible edge of the tumor.

Smoking and risk of death due to pulmonary tuberculosis: a case-control comparison in 103 population centers in China

OBJECTIVE

To examine the relationship between smoking and the risk of tuberculosis (TB) mortality in a large population-based case-control study in China using an alternative control group selection design.

METHODS

During 1989-1991, a nationwide mortality survey was conducted of deaths among adults from 1986 to 1988. Surviving spouses or other informants provided detailed information about their own as well as the deceased person's smoking history. For the present study, all persons who died of TB at age > or =40 were used as cases, whereas all surviving spouses of deceased persons who died from causes other than those attributed to smoking were used as controls.

RESULTS

It was estimated that for 22.5% of men and 6.6% of women, smoking was a contributing factor for TB deaths. Although variations in TB death rates by smoking status were not obvious before the age of 60, these differences increased substantially with age thereafter. This trend occurred in both urban and rural areas, although rural TB death rates were double those observed in urban areas.

CONCLUSIONS

Tobacco smoking was associated with a large number of deaths from TB in China. The current study confirms results from previous studies about the relationship between smoking and TB mortality.

Variation of meat quality traits among five genotypes of chicken

The main objective of this study was to examine the diversity of meat quality traits among 5 chicken genotypes. The genotypes included 2 Chinese native breeds (Wenchang,WCH, and Xianju), 1 commercial broiler line (Avian, AV), 1 commercial layer line (Hy-Line Brown, HLB), and 1 Chinese commercial broiler line (Lingnanhuang, LNH) synthesized by exotic and native breeds, which were slaughtered at their market ages: 16, 7, 16, and 8 wk, respectively. The effects of genotype, muscle type, and sex on meat quality traits were examined. Birds from slow-growing genotypes (WCH, Xianju, and HLB) exhibited higher shear value, inosine-5'-monophosphate concentration, lower cook loss, and more fat than those from fast-growing genotypes (AV and LNH). Chickens from WCH possessed the lowest expressible moisture, cook loss, and the highest lipid (%) among the 3 slow-growing genotypes. The HLB birds were intermediate in expressible moisture and cook loss and lowest in lipid among all genotypes. The LNH cross birds were similar to AV broilers in most meat quality parameters, although they had a lower shear force value and higher fat content than AV broilers. Breast muscle had higher expressible moisture, shear force, protein (%), inosine-5'-monophosphate content, lower cook loss, and lipid (%) than leg muscle. Muscles from male chickens had higher expressible moisture than those from the females. Variability of meat quality characteristics is mainly related to genotype and muscle type differences.

Reliability of environmental sampling to quantify Mycobacterium avium subspecies paratuberculosis on California free-stall dairies

The reliability of environmental sampling to quantify Mycobacterium avium ssp. paratuberculosis (MAP) based on collector and time was evaluated. Fecal slurry samples were collected using a standardized protocol simultaneously by 2 collectors of different experience levels. Samples were collected from 30 cow pens on 4 dairies every other day on 3 occasions while cow movements between pens were minimal. The 4 study herds had moderate MAP seroprevalence and were housed in free-stall dairies in central California. Results of testing the environmental samples for MAP using PCR and culture were strongly correlated. The reliability of environmental sampling simultaneously by different collectors as estimated by the intraclass correlation coefficient was excellent (81%) for PCR and good (67%) for culture and may justify comparison of quantitative results of samples collected by different investigators. The reliability of environmental sampling over a 5-d period was good (67 and 64% for PCR and culture results, respectively), which justifies the utility of environmental sampling to identify pens with a high MAP bioburden between routine cow pen changes on a dairy. Environmental sampling of free-stall pens using the standardized sampling protocol yielded comparable PCR and culture results across collectors with different experience levels and at different times within a 5-d period.

Small Interfering RNA-Mediated Silencing of Heat Shock Protein 27 (HSP27) Increases Chemosensitivity to Paclitaxel by Increasing Production of Reactive Oxygen Species in Human Ovarian Cancer Cells (HO8910)

Increasing evidence indicates that reactive oxygen species (ROS) are involved in paclitaxel cytotoxicity. Modulating the oxidant–antioxidant status of tumour cells may increase the antitumour activity of paclitaxel. The cytoprotective roles of heat shock protein 27 (HSP27) include chaperoning cellular proteins, regulating apoptotic signalling and modulating oxidative stress. Immunohistochemical staining for HSP27 in human ovarian cancer specimens showed HSP27 was associated with aggressive malignant ovarian disease. Small interfering RNA (siRNA) was used to down-regulate HSP27 in human ovarian cancer cells (HO8910). Reduction of HSP27 expression increased the in vitro chemosensitivity of HO8910 cells to paclitaxel and increased paclitaxel-induced apoptosis and ROS production, although the ROS scavenger, N-acetyl-l-cysteine, partly offset the effects of HSP27 siRNA. Thus, gene knock-down of HSP27 offsets the role of this protein in resisting oxidant stress, thereby indirectly increasing the sensitivity of cells to paclitaxel. The siRNA-induced knock-down of HSP27 could be a novel and potent strategy to help overcome chemotherapeutic resistance to paclitaxel in epithelial ovarian cancer cells.