Dynamic changes of global DNA methylation and hypermethylation of cell adhesion-related genes in rat kidneys in response to ochratoxin A

Ochratoxin A (OTA), which is found in a variety of food products, is associated with the development of nephrotoxicity and carcinogenicity in rats and has raised public health concerns. A previous study in our laboratory indicated that OTA exposure induced cytotoxicity by decreasing global DNA methylation in vitro. However, the relationship between OTA-induced nephrotoxicity and DNA methylation changes in vivo remains unclear. The object of this study was to investigate whether OTA can change global DNA methylation or alter the expression of several critical tumour-related genes by inducing methylation modifications before carcinogenesis. We focused on the mechanism of action of OTA in regard to DNA methylation, including the expression of DNA methyltransferases and the regulation of specific cell signalling pathways. Dynamic and dose-dependent changes of global DNA methylation were observed during OTA-induced nephrotoxicity and probably associated with the expression of DNA methyltransferase 1. 13-week exposure of OTA caused hypermethylation in the promoters of critical cell adhesion-related genes, E-cadherin and N-cadherin, leading to reduction of the corresponding mRNA expression, accompanied by transcriptional activation of the Wnt and PI3K/AKT pathways. These findings suggested that long-term OTA exposure could disrupt DNA methylation profile, which might be one of the possible mechanisms of OTA-induced nephrotoxicity.

Correlation between natriuretic peptide receptor C (NPR3) gene polymorphisms and hypertension in the Dai people of China

Hypertension affects one-fifth of the world population. Genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) that correlated with hyper-tension in large samples. However, the genetic mutations leading to hypertension might differ among various populations, as they have different origins and are subjected to different environmental pressures. Therefore, additional studies are urgently needed to verify the GWAS findings across different populations. This study focused on the natriuretic peptide receptor C gene (NPR3), one of the hypertension-positive genes identified in a GWAS of an East Asian population. The correlation analysis between NPR3 and hypertension was replicated in 450 Chinese Dai (235 patients vs 215 controls) and 484 Chinese Mongolian (211 patients vs 273 controls) individuals. The positive SNP identified by GWAS analysis and three other tag SNPs representing the NPR3 linkage disequilibrium (LD) block regions were selected for genotyping. The results revealed that the rs1173766 polymorphism was associated with the occurrence of hypertension (χ(2) = 6.87, P = 0.0088), and that the T allele should be protective in the Dai ethnic group. Consider-ing a close LD block at the 3' end of the NPR3 gene in the East Asian population, we speculate that there might be a mutation in the last five exons or the 3' untranslated region of NPR3 that could change the structure or expression of the NPR3 gene. However, in the Mongolian ethnic group, these SNPs were not associated with the incidence of hypertension, suggesting population heterogeneity for the genetic factors that contribute to hypertension.

Novel VN/C nanocomposites as methanol-tolerant oxygen reduction electrocatalyst in alkaline electrolyte

A novel VN/C nanostructure consisting of VN nanoparticles and graphite-dominant carbon layers is synthesized by nitridation of V₂O₅ using melamine as reductant under inert atmosphere. High crystalline VN nanoparticles are observed to be uniformly distributed in carbon layers with an average size of ca13.45 nm. Moreover, the electrocatalytic performance of VN/C towards oxygen reduction reaction (ORR) in alkaline electrolyte is fascinating. The results show that VN/C has a considerable ORR activity, including a 75 percent value of the diffusion-limited current density and a 0.11 V smaller value about the onset potential with respect to Pt/C catalyst. Moreover, the excellent methanol-tolerance performance of VN/C has also been verified with 3 M methanol. Combined with the competitive prices, this VN/C nanocomposite can serve as an appropriate non-precious methanol-tolerant ORR catalyst for alkaline fuel cells.

Neutron yield enhancement in laser-induced deuterium-deuterium fusion using a novel shaped target

Neutron yields have direct correlation with the energy of incident deuterons in experiments of laser deuterated target interaction [Roth et al., Phys. Rev. Lett. 110, 044802 (2013) and Higginson et al., Phys. Plasmas 18, 100703 (2011)], while deuterated plasma density is also an important parameter. Experiments at the Shenguang II laser facility have produced neutrons with energy of 2.45 MeV using d (d, n) He reaction. Deuterated foil target and K-shaped target were employed to study the influence of plasma density on neutron yields. Neutron yield generated by K-shaped target (nearly 10(6)) was two times higher than by foil target because the K-shaped target results in higher density plasma. Interferometry and multi hydro-dynamics simulation confirmed the importance of plasma density for enhancement of neutron yields.

Correlation of post-stroke fatigue with glucose, homocysteine and functional disability

BACKGROUND

Our aim was to clarify the correlation between fatigue during the acute stage of stroke with serum glucose and homocysteine (Hcy) levels and functional disability.

MATERIALS AND METHODS

A case group of 214 patients and a control group of 214 subjects were recruited during the same period. The serum glucose, Hcy, blood lipid and fibrinogen (FIB) levels of patients were determined. Fatigue was assessed using the Fatigue Severity Scale (FSS). Patients with an FSS score ≥4 points were defined as having fatigue. Stroke severity and the level of functional disability were assessed with the National Institutes of Health Stroke Scale (NIHSS) and the Barthel-20 Index (BI-20), respectively.

RESULTS

The incidence of fatigue in the case group was higher than that in the control group (P < 0.001). Within the case group, the fatigue group showed higher serum levels of glucose and Hcy, and a lower BI-20 score compared to the non-fatigue group (P < 0.001). Age, gender, chronic disease history, the NIHSS score and the serum blood lipid and FIB levels were not significantly different between the two groups. In the fatigue group, the serum glucose and Hcy levels showed a positive effect and the BI-20 score showed a negative effect on the FSS score (P < 0.01). Age, gender, chronic disease history, the NIHSS score and the serum blood lipid and FIB levels did not significantly affect the FSS score.

CONCLUSIONS

The serum glucose and Hcy levels and functional disability are closely related to fatigue during the acute stage of ischaemic stroke.

Tunable dielectric properties of ferrite-dielectric based metamaterial

A ferrite-dielectric metamaterial composed of dielectric and ferrite cuboids has been investigated by experiments and simulations. By interacting with the electromagnetic wave, the Mie resonance can take place in the dielectric cuboids and the ferromagnetic precession will appear in the ferrite cuboids. The magnetic field distributions show the electric Mie resonance of the dielectric cuboids can be influenced by the ferromagnetic precession of ferrite cuboids when a certain magnetic field is applied. The effective permittivity of the metamaterial can be tuned by modifying the applied magnetic field. A good agreement between experimental and simulated results is demonstrated, which confirms that these metamaterials can be used for tunable microwave devices.

Allogeneic hematopoietic stem cell transplantation in children with aplastic anemia

The aim of this study was to prospectively investigate the efficacy and safety of fully matched allogeneic hematopoietic stem cell transplants in children with severe aplastic anemia in China. A total of twenty patients with severe aplastic anemia were enrolled in our study. Thirteen cases underwent transplantation with fully human leukocyte antigen (HLA)-matched, granulocyte-colony stimulating factor (G-CSF)-primed bone marrow and peripheral blood stem cells (PBSCs) from matching sibling donors. One patient received fully HLA-matched bone marrow from an unrelated donor. Six patients received fully HLA-matched G-CSF-primed PBSCs from unrelated donors. The conditioning regimen included fludarabine, cyclophosphamide, and rabbit anti-thymocyte globulin. Graft-versus-host disease prophylaxis was conducted with cyclosporin A and short-course methotrexate. The median follow-up duration was 3.08 years (range, 0.83-8.41years). The median time of neutrophil recovery (>0.5 x 10(9)/L) was 14 days (range, 10-20 days), and the median time of platelet recovery (>20 x 10(9)/L) was 19 days (range, 14-31 days). The survival rate at the cutoff point of follow-up was 95.0% (19/20). Initial engraftment rate was 95% (19/20). Late graft failure (graft failures occurring 1 year or longer after transplantation) was observed in one patient. Only one patient developed Grade I acute graft-versus-host disease. Two cases suffered from Epstein- Barr virus (EBV)-associated post-transplant lymphoproliferative disorder and remitted after treatment with rituximab. One patient was diagnosed with hyperthyroidism 2.5 years after transplantation. Our study indicated that allogeneic hematopoietic stem cell transplantation is an effective and safe treatment for children with severe aplastic anemia in China.

Thumb carpometacarpal joint total arthroplasty: a systematic review

Thumb carpometacarpal joint total arthroplasty has been undertaken for many years. The proponents believe the short-term outcomes are better than trapeziectomy and its variants, but the longer term complications are often higher. This systematic review of all peer reviewed articles on thumb carpometacarpal joint total arthroplasty for osteoarthritis shows that there are reports of many implants. Some are no longer available. The reported outcomes are very variable: for some there are good long-term outcomes to beyond 10 years ; for others there are unacceptably high early rates of failure. Overall the published evidence does not show that total arthroplasty is better than trapeziectomy and its variants yet there is a higher complication rate and significant extra cost of using an implant. Future research needs to compare total arthroplasty with trapeziectomy to assess short term results where the arthroplasties may be better, long-term outcomes and the healthcare and personal costs so that surgeons and patients can make fully informed choices about the treatment of symptomatic thumb carpometacarpal joint osteoarthritis.

Effects of dietary supplementation of selenium-enriched probiotics on production performance and intestinal microbiota of weanling piglets raised under high ambient temperature

This study was designed to evaluate the efficacy of selenium-enriched probiotics (SeP) on production performance and intestinal microbiota of piglets raised under high ambient temperature. Forty-eight cross-bred weanling piglets (28 days old), randomly allotted into 12 pens (four piglets/pen) and four dietary treatments (three pens/treatment group), were fed ad libitum for 42 days a basal diet (Con) or the basal diet supplemented with probiotics (Pro), sodium selenite (ISe) or a SeP preparation. Blood and faecal samples were collected on days 0, 14, 28 and 42 post-treatment. The SeP group had higher final BW (p < 0.05), greater ADG (p < 0.05) and lower FCR (p < 0.01) than the Pro, ISe or Con group. The diarrhoea incidence rate of either SeP or Pro group was lower (p < 0.01) than the ISe or Con group. Blood Se concentration and GSH-Px activity were both higher (p < 0.01) in the SeP than in the Pro, ISe or Con group. On days 28 and 42, the serum concentrations of T3 were higher (p < 0.01) and T4 lower (p < 0.01) in the SeP than in the ISe group, and the T3 and T4 concentrations in the ISe group, in turn, were higher (p < 0.05) and lower (p < 0.01), respectively, than in the Pro or Con group. Also on days 28 and 42, the faecal counts of lactobacillus bacteria were higher (p < 0.01) while Escherichia coli lower (p < 0.01) in the SeP or Pro group as compared to the ISe or Con group. The results of RFLP showed that the faecal microbial flora in the SeP group changed the most (numerically) as compared to the Pro or ISe group. These results suggest that the SeP product may serve as a better alternative to antibiotics than the solo probiotics for using as a growth promoter for weanling piglets.

Search for neutrinos from annihilation of captured low-mass dark matter particles in the sun by super-kamiokande

Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV/c^{2}-200-GeV/c^{2}) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent WIMP-proton cross section for WIMP masses below 200  GeV/c^{2} (at 10  GeV/c^{2}, 1.49×10^{-39}  cm^{2} for χχ→bb[over ¯] and 1.31×10^{-40}  cm^{2} for χχ→τ^{+}τ^{-} annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent coupling in the few-GeV/c^{2} mass range.

Oxytocin down-regulates mesenteric afferent sensitivity via the enteric OTR/nNOS/NO/KATP pathway in rat

BACKGROUND

Oxytocin plays an analgesic role in modulation of nociception and pain. Most work to date has focused on the central mechanisms of oxytocin analgesia, but little is known about whether peripheral mechanisms are also involved.

METHODS

The mesenteric afferent discharge was recorded in vitro. The expressions of oxytocin receptor (OTR) and neuronal nitric oxide synthase (nNOS) in longitudinal muscle myenteric plexus (LMMP) was identified by immunofluorescence.

KEY RESULTS

Oxytocin per se had no effect on the jejunal mesenteric afferent discharge, however, it markedly attenuated the bradykinin- or distention-evoked increase of mesenteric afferent discharge, which was mimiced by the nitric oxide (NO) donor sodium nitroprusside (SNP). Pretreatment of either NOS inhibitor L-NAME or NPLA largely reduced the inhibitory effect of oxytocin on bradykinin-evoked mesenteric afferent discharge. Such effect, to a large extent, was also alleviated by N-and P-type voltage-dependent calcium channel antagonists or KATP blocker glibenclamide. In addition, immunofluorescence studies show strong colocalization of OTR with nNOS in LMMP of the rat jejunum.

CONCLUSIONS & INFERENCES

Oxytocin down-regulates the mesenteric afferent sensitivity through nNOS-NO-KATP pathway. Our findings may reveal a new peripheral mechanism for oxytocin analgesia.

Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn₅

We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn₅. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J₁-J₂ model that also naturally explains the magnetic spin-spiral ground state of CeRhIn₅ and yields a dominant in-plane nearest-neighbor magnetic exchange constant J₀=0.74(3)  meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn₅ (T=Co, Rh, Ir) class of heavy-fermion materials.

Measurement of the inclusive electron neutrino charged current cross section on carbon with the T2K near detector

The T2K off-axis near detector ND280 is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies ∼1  GeV as a function of electron momentum, electron scattering angle, and four-momentum transfer of the interaction. The total flux-averaged ν(e) charged current cross section on carbon is measured to be ⟨σ⟩(ϕ)=1.11±0.10(stat)±0.18(syst)×10⁻³⁸ cm²/nucleon. The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is 1.23×10⁻³⁸ cm²/nucleon and the GENIE prediction is 1.08×10⁻³⁸ cm²/nucleon. The total ν(e) charged current cross-section result is also in agreement with data from the Gargamelle experiment.

Microcontroller-based locking in optics experiments

Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

Intense high repetition rate Mo Kα x-ray source generated from laser solid interaction for imaging application

We report an efficient Mo Kα x-ray source produced by interaction of femtosecond Ti: sapphire laser pulses with a solid Molybdenum target working at 1 kHz repetition rate. The generated Mo Kα x-ray intensity reaches to 4.7 × 10(10) photons sr(-1) s(-1), corresponding to an average power of 0.8 mW into 2π solid angle. The spatial resolution of this x-ray source is measured to be 26 lp/mm. With the high flux and high spatial resolution characteristics, high resolving in-line x-ray radiography was realized on test objects and large size biological samples within merely half a minute. This experiment shows the possibility of laser plasma hard x-ray source as a new low cost and high resolution system for radiography and its ability of ultrafast x-ray pump-probe study of matter.

p16 expression in patients with cervical cancer and its prognostic significance: meta-analysis of published literature

OBJECTIVES

p16, a tumour suppressor, is unable to express its suppressive effects following interaction with E7-retinoblastoma protein. Previous reports have suggested that p16 immunostaining allows precise identification of cervical intra-epithelial neoplasia and cervical cancer lesions in biopsies. The prognostic value of p16 expression in cervical cancers has been evaluated for several years, but the results remain controversial. As such, the authors undertook a systematic review and meta-analysis of studies assessing the impact of p16 expression on overall survival and disease-free survival.

STUDY DESIGN

Medline, Embase and China National Knowledge Infrastructures were searched to identify studies on the prognostic impact of p16 expression in patients with cervical cancer. In total, 1070 patients from 10 eligible studies were included in the analysis. Pooled risk ratios (RRs) with 95% confidence intervals (95% CI) were calculated.

RESULTS

A significant association was found between p16 expression and increased disease-free survival (RR 0.60; 95% CI 0.44-0.82; p=0.001). However, no significant association was found between p16 and overall survival.

CONCLUSION

p16 expression may be predictive of a favourable prognosis in patients with cervical cancer. However, large-scale, multicentre and well-matched cohort studies are warranted to confirm this finding.