Enhanced formation and impaired degradation of neutrophil extracellular traps in dermatomyositis and polymyositis: a potential contributor to interstitial lung disease complications

Dermatomyositis (DM) and polymyosits (PM) are systemic autoimmune diseases whose pathogeneses remain unclear. Neutrophil extracellular traps (NETs) are reputed to play an important role in the pathogenesis of autoimmune diseases. This study tests the hypothesis that NETs may be pathogenic in DM/PM. Plasma samples from 97 DM/PM patients (72 DM, 25 PM) and 54 healthy controls were tested for the capacities to induce and degrade NETs. Plasma DNase I activity was tested to further explore possible reasons for the incomplete degradation of NETs. Results from 35 DM patients and seven PM patients with interstitial lung disease (ILD) were compared with results from DM/PM patients without ILD. Compared with control subjects, DM/PM patients exhibited a significantly enhanced capacity for inducing NETs, which was supported by elevated levels of plasma LL-37 and circulating cell-free DNA (cfDNA) in DM/PM. NETs degradation and DNase I activity were also decreased significantly in DM/PM patients and were correlated positively. Moreover, DM/PM patients with ILD exhibited the lowest NETs degradation in vitro due to the decrease in DNase I activity. DNase I activity in patients with anti-Jo-1 antibodies was significantly lower than in patients without. Glucocorticoid therapy seems to improve DNase I activity. Our findings demonstrate that excessively formed NETs cannot be degraded completely because of decreased DNase I activity in DM/PM patients, especially in patients with ILD, suggesting that abnormal regulation of NETs may be involved in the pathogenesis of DM/PM and could be one of the factors that initiate and aggravate ILD.

Preparation and malachite green adsorption behavior of polyurethane/chitosan composite foam

A series of Polyurethane/Chitosan composite foam with different chitosan content of 5–25 wt% was prepared, and their adsorption performance of malachite green (MG) in aqueous solutions was investigated by pH values, contact time, temperatures and chitosan content. It was observed that Polyurethane/Chitosan composite foam exhibited well-developed open cell structures. Malachite green adsorption capacities of the composite foam increased with the increment of chitosan content in composite foam. Polyurethane/Chitosan composite foam with 20% chitosan content exhibited a maximum removal capacity of 16.67 mg/g and 95.60% MG removal efficiency. In addition, MG adsorption capacities of composite foam increased with pH value increase, 30℃ was the optimum temperature, which affects the adsorption process, and the adsorption maximum was attained within 12 hours. The result of SEM showed the prepared composite foam possess well-developed open cell structures. The MG adsorption kinetics and equilibrium isotherm of the composite foam were well described with the pseudo-second order kinetic model and Langmuir isotherm model, respectively. This work provided an attractive adsorbent for removing of the hazardous materials from water.

Combined analysis of νμ disappearance and νμ→νe appearance in MINOS using accelerator and atmospheric neutrinos

We report on a new analysis of neutrino oscillations in MINOS using the complete set of accelerator and atmospheric data. The analysis combines the ν(μ) disappearance and ν(e) appearance data using the three-flavor formalism. We measure |Δm(32)(2)| = [2.28-2.46] × 10(-3) eV(2) (68% C.L.) and sin(2)θ(23) = 0.35-0.65 (90% C.L.) in the normal hierarchy, and |Δm(32)(2)| = [2.32-2.53] × 10(-3) eV(2) (68% C.L.) and sin(2)θ(23) = 0.34-0.67 (90% C.L.) in the inverted hierarchy. The data also constrain δ(CP), the θ(23} octant degeneracy and the mass hierarchy; we disfavor 36% (11%) of this three-parameter space at 68% (90%) C.L.

Synthesis and Properties of a Novel Intumescent Flame Retardant and its Application in LLDPE

In this study, a novel phosphorus-containing flame retardant (IFR) of spirocyclic pentaerythritol diphosphonate dinitroguanidine (SPDD) was successfully synthesized, which was characterized by 1H NMR, 31P NMR and FTIR spectra. At the same time, the SPDD was used in LLDPE to prepare flame-retardant materials whose flammability and thermal behavior were studied by thermogravimetric analysis (TGA), limiting oxygen index (LOI) and scanning electron microscopy (SEM). The TGA data showed that SPDD could effectively enhance the thermal stability and char residue of LLDPE/IFR composite. And with the increase of SPDD, the LOI value of LLDPE/IFR increases obviously. When SPDD reached 30 wt%, the LOI value of LLDPE/IFR reaches 31 %. The SEM also shows the surface of intumescent chars of LLDPE/IFR (30 %) has many sphere-like swollen bubbles.

Glucose-regulated protein 78 may play a crucial role in promoting the pulmonary microvascular remodeling in a rat model of hepatopulmonary syndrome

OBJECTIVE

This study is to investigate the role of glucose-regulated protein 78 (GRP78) in the pulmonary microvascular remodeling during hepatopulmonary syndrome (HPS) development.

METHODS

The rat models with liver cirrhosis and HPS were induced by multiple pathogenic factors for 4 to 8 wk. The concentrations of alanine transferase (ALT) and endotoxin in plasma were detected in the models, followed by the detection of GRP78 expression. RT-PCR, quantitative real-time PCR and Western blotting were employed to assess the mRNA and protein expression levels of vascular endothelial growth factor (VEGF), respectively. Immunohistochemistry staining was used to examine the expression of a specific vascular marker, factor VIII-related antigen (FVIII-RAg), and several cell proliferation- and apoptosis-related proteins, including CHOP/GADD153, caspase-12, Bcl-2 and nuclear factor (NF)-κB.

RESULTS

The levels of endotoxin and ALT in plasma were gradually increased as the disease progressed, so did GRP78, which were in a positive correlation. The expression levels of VEGF (both mRNA and protein) and FVIII-RAg were significantly elevated in the HPS models, indicating active angiogenesis, which was also positively correlated with GRP78 expression. Furthermore, the expression levels of the pro-apoptotic proteins of CHOP/GADD153 and caspase-12 were dramatically decreased, while the anti-apoptotic proteins of Bcl-2 and NF-κB were significantly elevated, in the HPS models. There were also close correlation between these proteins and GRP78.

CONCLUSIONS

Over-expression of GRP78 in lungs may be the critical pathogenic factor for HPS. Through promoting cell proliferation and survival and inhibiting apoptosis, GRP78 may promote the pulmonary microvascular remodeling in HPS pathogenesis. Our results provide a potential therapeutic target for clinical prevention and treatment for HPS and related complications.

Selective inhibition of protein kinase C β2 attenuates the adaptor P66 Shc-mediated intestinal ischemia-reperfusion injury

Apoptosis is a major mode of cell death occurring during ischemia–reperfusion (I/R) induced injury. The p66^Shc adaptor protein, which is mediated by PKCβ, has an essential role in apoptosis under oxidative stress. This study aimed to investigate the role of PKCβ₂/p66^Shc pathway in intestinal I/R injury. In vivo, ischemia was induced by superior mesenteric artery occlusion in mice. Ruboxistaurin (PKCβ inhibitor) or normal saline was administered before ischemia. Then blood and gut tissues were collected after reperfusion for various measurements. In vitro, Caco-2 cells were challenged with hypoxia–reoxygenation (H/R) to simulate intestinal I/R. Translocation and activation of PKCβ₂ were markedly induced in the I/R intestine. Ruboxistaurin significantly attenuated gut damage and decreased the serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Pharmacological blockade of PKCβ₂ suppressed p66^Shc overexpression and phosphorylation in the I/R intestine. Gene knockdown of PKCβ₂ via small interfering RNA (siRNA) inhibited H/R-induced p66^Shc overexpression and phosphorylation in Caco-2 cells. Phorbol 12-myristate 13-acetate (PMA), which stimulates PKCs, induced p66^Shc phosphorylation and this was inhibited by ruboxistaurin and PKCβ₂ siRNA. Ruboxistaurin attenuated gut oxidative stress after I/R by suppressing the decreased expression of manganese superoxide dismutase (MnSOD), the exhaustion of the glutathione (GSH) system, and the overproduction of malondialdehyde (MDA). As a consequence, ruboxistaurin inhibited intestinal mucosa apoptosis after I/R. Therefore, PKCβ₂ inhibition protects mice from gut I/R injury by suppressing the adaptor p66^Shc-mediated oxidative stress and subsequent apoptosis. This may represent a novel therapeutic approach for the prevention of intestinal I/R injury.

Maggot debridement therapy for the treatment of diabetic foot ulcers: a meta-analysis

OBJECTIVE

To assess the potential efficacy of maggot debridement therapy (MDT) compared with standard care for diabetic foot ulcers (DFUs).

METHOD

A meta-analysis was performed on the evidence for MDT for DFUs. Databases, including PubMed, Web of Science, the Cochrane Library, EMbase, EBSCOhost, Springer Link, ScienceDirect and Ovid-Medline, were electronically searched for randomised controlled trials, case-control studies and controlled clinical trials, up to 31 December 2012, and relevant references of the included articles were also manually searched. The literature was screened, the data were extracted and the methodological quality of the included studies was assessed. Meta-analyses were performed on the included data, for the outcomes healing rate, time to healing, incidence of infection, amputation rate and antibiotic-free days or antibiotics usage.

RESULTS

Overall, four studies comparing MDT with standard therapy on a total of 356 participants were included. The results of meta-analyses suggested that the MDT group was significantly superior to the control group in the percentage of DFUs to achieve full healing (RR=1.8, 95%CI=1.07; 3.02; p=0.03), amputation rate (RR=0.41, 95%CI=0.20; 0.85; p=0.02), time to healing (RR=-3.70, 95%CI=-5.76; -1.64; p=0.0004) and number of antibiotic-free days (126.8 ± 30.3 days vs 81.9 ± 42.1 days; p=0.001); however, collated differences in incidence of infection after intervention revealed no evidence of a difference between the MDT and control groups (RR=0.82, 95%CI=0.65; 1.04, p=0.10).

CONCLUSION

Although MDT may be a scientific and effective therapy in treatment of DFUs, the evidence is too weak to routinely recommend it for treatment. Large studies and sample sizes are needed to assess the efficacy and safety of MDT in the treatment of DFUs.

DECLARATION OF INTEREST

There were no external sources of funding for this study. The authors have no conflicts of interest to declare with regard to this work or its contents. X. Tian and X.M. Liang contributed equally to this work.

Expression of the 78 kD glucose-regulated protein is induced by endoplasmic reticulum stress in the development of hepatopulmonary syndrome

OBJECTIVE

This study is to explore the role of 78 kD glucose-regulated protein (GRP78) in the development of hepatopulmonary syndrome (HPS) in rats.

METHODS

The rat model of liver cirrhosis and HPS were induced with multiple pathogenic factors. Hematoxylin and eosin (H & E) staining was performed to detect the pathological changes of the lung and liver tissues. The levels of alanine transferase (ALT), endotoxin, and tumor necrosis factor-α (TNF-α) in plasma and TNF-α and malondialdehyde (MDA) in lung tissues were detected. RT-PCR and Western blotting were conducted to detect the mRNA and protein expression levels of GRP78 in lungs.

RESULTS

The plasma endotoxin level was gradually increased as HPS developed, and the mRNA and protein expression levels of GRP78 in lungs were also increased as the disease progressed. The levels of ALT and TNF-α in plasma and the contents of TNF-α and MDA in lung tissues were gradually increased along with the disease progression, with a strong positive correlation. Compared with controls, the plasma TNF-α level and the mRNA and protein expression levels of GRP78 in lung tissues were significantly higher in rats with HPS. The levels of endotoxin and ALT in plasma and the level of MDA in lungs were significantly higher in rats with HPS than controls.

CONCLUSIONS

The increased GRP78 expression is indicative of endoplasmic reticulum stress response during HPS, which may play an important role in the disease pathogenesis.

[Effect of ropivacaine on proliferation and migration of rat bone marrow mesenchymal stem cells]

OBJECTIVE

To observe the influence of ropivacaine on the proliferation and migration of rat bone marrow mesenchymal stem cells (BMSCs) and provide basis for the clinical application of BMSCs.

METHODS

Rat BMSCs were isolated and cultured by adherence method. Surface markers of BMSCs were examined by flow cytometry. Multipotent differentiation of BMSCs was detected by induced adipogenesis, osteogenesis and muscular differentiation. Proliferation of BMSCs was examined by CCK-8 and Brdu incorporation after ropivacaine treatment at different concentrations. Migration of BMSCs was tested by cell scratch assay and Millicell experiment.

RESULTS

Cultured cells had representative appearance and surface markers of BMSC, and they had potential multiple differentiation. Ropivacaine treatment at 50 and 100 μmol/L significantly reduced the proliferation rate of BMSCs and Brdu incorporation rate. There was significant difference compared with the control group (P<0.05). Cellular scratch assay and migration experiment indicated that ropivacaine significantly reduced the migration of BMSCs. There was significant difference compared with the control group (P<0.05). All these mentioned effects of ropivacaine on BMSCs were dose-dependent. There was significant difference between groups (P<0.05).

CONCLUSION

Ropivacaine can significantly reduce the proliferation and migration of rat BMSCs, suggesting that the influence of local anesthetics on BMSCs has to be taken into account when BMSCs are used in clinical practice.

Cost-effectiveness of a 12-dose regimen for treating latent tuberculous infection in the United States

SETTING

A large randomized controlled trial recently showed that for treating latent tuberculous infection (LTBI) in persons at high risk of progression to tuberculosis (TB) disease, a 12-dose regimen of weekly rifapentine plus isoniazid (3HP) administered as directly observed treatment (DOT) can be as effective as 9 months of daily self-administered isoniazid (9H).

OBJECTIVES

To assess the cost-effectiveness of 3HP compared to 9H.

DESIGN

A computational model was designed to simulate individuals with LTBI treated with 9H or 3HP. Costs and health outcomes were estimated to determine the incremental costs per active TB case prevented and per quality-adjusted life year (QALY) gained by 3HP compared to 9H.

RESULTS

Over a 20-year period, treatment of LTBI with 3HP rather than 9H resulted in 5.2 fewer cases of TB and 25 fewer lost QALYs per 1000 individuals treated. From the health system and societal perspectives, 3HP would cost respectively US$21,525 and $4294 more per TB case prevented, and respectively $4565 and $911 more per QALY gained.

CONCLUSIONS

3HP may be a cost-effective alternative to 9H, particularly if the cost of rifapentine decreases, the effectiveness of 3HP can be maintained without DOT, and 3HP treatment is limited to those with a high risk of progression to TB disease.

Changes in phosphatidylinositol 3-kinase 55 kDa gamma expression and subcellular localization may be caspase 6 dependent in paraquat-induced SH-SY5Y apoptosis

The neurotoxin paraquat (PQ) causes apoptosis of dopaminergic neurons in mammalian cell culture and animal models, mimicking an important pathological feature of Parkinson's disease (PD). The phosphoinositide 3-kinase (PI3K)/Akt pathway is critical for several major survival signals in central nervous system neurons. Phosphatidylinositol 3-kinase 55 kDa gamma (p55PIK) is a regulatory subunit of PI3Ks with important roles in cell proliferation, antiapoptosis, and cell cycle progression. However, p55PIK involvement in mechanisms regarding progression and maintenance of neurodegenerative diseases is largely undetermined. We used PQ-induced apoptosis in human dopaminergic SH-SY5Y cells to investigate the association between p55PIK expression levels, subcellular location, and apoptosis. p55PIK expression was reduced in SH-SY5Y cells and p55PIK messenger RNA and protein expression levels were decreased after PQ treatment. Apoptosis induced by PQ was associated with caspase activation and decreased p55PIK expression. Restoration of p55PIK expression was observed after coincubation with a caspase inhibitor. Overexpressed full-length p55PIK in SH-SY5Y and human embryonic kidney 293 cells showed specific distribution in the nucleus and was cleaved in vitro by recombinant caspase 6 (C6), but not C3 and C7. A p55PIK construct lacking 24 N-terminal amino acids (N24) was tested for the presence of a potential C6-recognizable sequence and was found to express its proteins outside the nucleus. The results suggest that p55PIK may be involved in PQ-induced apoptosis signal transduction and that N24 is crucial for p55PIK subcellular localization. Thus, p55PIK could be a substrate of activated C6 during apoptosis, leading to loss of original biological functions and redistribution to disturb cell cycle progression.

A conserved extraordinarily long serine homopolymer in Dictyostelid amoebae

Eukaryotic protein sequences often contain amino-acid homopolymers that consist of a single amino acid repeated from several to dozens of times. Some of these are functional but others may persist largely because of high expansion rates due to DNA slippage. However, very long homopolymers with over a hundred repeats are very rare. We report an extraordinarily long homopolymer consisting of 306 tandem serine repeats from the single-celled eukaryote Dictyostelium discoideum, which also has a multicellular stage. The gene has a paralog with 132 repeats and orthologs, also with high serine repeat numbers, in various other Dictyostelid species. The conserved gene structure and protein sequences suggest that the homopolymer is functional. The high codon diversity and very poor alignment of serine codons in this gene between species similarly indicate functionality. This is because the serine homopolymer is conserved despite much DNA sequence change. A survey of other very long amino-acid homopolymers in eukaryotes shows that high codon diversity is the rule, suggesting that these too may be functional.

Accumulation and tolerance characteristics of zinc in Agropyron cristatum plants exposed to zinc-contaminated soil

In phytoremediation, plants are used to stabilize or remove toxins from soil. In this study, a pot experiment was conducted in a greenhouse to evaluate the phytoremediation potential of Agropyron cristatum (Poaceae) grown on Zinc (Zn) contaminated soils. Results indicated that Zn accumulation in both shoots and roots increased with soil Zn concentration, and Zn concentrations in roots were greater than in shoots. A significantly negative correlation was found between translocation factor or bioconcentration factor values and Zn concentrations in soil. Overall, A. cristatum was Zn excluder with an innate capacity to tolerate Zn stress and may have potential for the phytostabilization of sites contaminated with Zn.

Role of silicon in alleviating salt-induced toxicity in white clover

To understand the role of silicon (Si) in alleviating sodium (Na) toxicity in Trifolium repens L. (white clover), the changes of biochemical and physiological parameters were investigated in four-week-old white clover seedlings exposed to 0 or 120 mM NaCl with or without 1.5 mM Si for 7 days. Results showed that added Si alone did not have any effects on the growth and Na⁺, K⁺ accumulations in white clover plants compared to the control (no added Si and NaCl). However, in the presence of NaCl, additional Si significantly enhanced the selective transport capacity for K⁺ over Na⁺ that contributed to reduced Na⁺ uptake and increased K⁺ uptake by roots, thereby improving its growth and K⁺/Na⁺ homeostasis in white clover. This study would provide a way for improving salt tolerance in important legume white clover forage.

Fine mapping of qhir1 influencing in vivo haploid induction in maize

Production of haploids by the in vivo haploid induction method has now become routine for generating new inbred lines in maize. In previous studies, a major quantitative trait locus (QTL) (qhir1) located in bin 1.04 was detected, explaining up to 66 % of the genotypic variance for haploid induction rate (HIR). Our objectives were to (1) fine-map qhir1 and (2) identify closely linked markers useful for marker-assisted breeding of new inducers. For this purpose, we screened a mapping population of 14,375 F2 plants produced from a cross between haploid inducer UH400 and non-inducer line 1680 to identify recombinants. Based on sequence information from the B73 reference genome, markers polymorphic between the two parents were developed to conduct fine mapping with these recombinants. A progeny test mapping strategy was applied to accurately determine the HIR of the 14 recombinants identified. Furthermore, F3 progeny of recombinant F2 plants were genotyped and in parallel evaluated for HIR. We corroborated earlier studies in that qhir1 has both a significantly positive effect on HIR but also a strong selective disadvantage, as indicated by significant segregation distortion. Altogether, we were able to narrow down the qhir1 locus to a 243 kb region flanked by markers X291 and X263.

CASP-9 gene functional polymorphisms and cancer risk: a large-scale association study plus meta-analysis

We investigated the association between CASP-9 polymorphisms and susceptibility to neoplasm. Fourteen studies with a total of 2733 neoplasm cases and 3352 healthy controls were included. Meta-analysis showed that the rs4645981 T allele and the rs4645981 T allele carrier were positively associated with neoplasm susceptibility [odds ratio (OR) = 1.43, 95% confidence interval (95%CI) = 1.12-1.81, P = 0.004; OR = 1.46, 95%CI = 1.10-1.93, P = 0.009, respectively]. However, the rs1052576 A allele, rs1052576 A carrier, rs2308941 T allele, and rs2308941 T carrier might decrease the risk of cancer (OR = 0.72, 95%CI = 0.58-0.89, P = 0.003; OR = 0.76, 95%CI = 0.63-0.92, P = 0.004; OR = 0.20, 95%CI = 0.09-0.45, P < 0.0001; OR = 0.21, 95%CI = 0.06-0.75, P = 0.02, respectively). There was no significant association between rs1263, rs1052571, rs2308950, rs4645978, rs4645980, rs4645982, and rs4646018 and cancer risk (all P > 0.05). In conclusion, this meta-analysis suggests that CASP-9 gene polymorphisms are involved in the pathogenesis of various cancers. The rs4645981 T allele and the rs4645981 T allele carrier might increase the risk of cancer, but the rs1052576 A allele, rs1052576 A carrier, rs2308941 T allele, and rs2308941 T carrier might be protective.

First Report of Impatiens necrotic spot virus on Hiemalis Begonia (Begonia × hiemalis) in Canada

Impatiens necrotic spot virus (INSV) is a member of the genus Tospovirus, and one of the prevalent viruses infecting ornamental plants, including begonia. Since the late 1980s, it has caused dramatic and unusual diseases on many flower crops, leading to considerable economic losses to the greenhouse floriculture industry (1). The western flower thrips, Frankliniella occidentalis (Pergande), is the only species currently known to vector INSV (1). In spring 2012, stunted plant growth and necrotic spots were observed on leaves of all Hiemalis begonias (Begonia × hiemalis Fotsch.) in a greenhouse in southwest Ontario, Canada. Initial symptoms were mosaic patterns, followed by necrotic spots on leaves, concentric rings, then necrotic areas on flowers, stem and vein necrosis, and finally stunting and burning of foliage similar to damage caused by sunburn or chemical injury. Thrips were observed colonizing nearby begonia plants. Leaf tissue from five symptomatic plants tested positive for INSV in a double-antibody sandwich (DAS)-ELISA with INSV-specific ImmunoStrips (Agdia Inc., Elkhart, IN). To confirm this, five of the leaf samples that were found to be positive for INSV in ELISA tests were mechanically inoculated to 10 plants of Hiemalis Begonia. Out of the 10 inoculated plants, eight produced necrotic local lesions and necrotic spots that are typical of INSV infection, followed by systemic infection of upper leaves 30 days after inoculation. The presence of INSV in the eight symptomatic plants was confirmed using the commercial INSV Pocket Diagnostic Kit (Forsite Diagnostics Ltd., York, UK) according to the manufacturer's instructions. Results showed that all eight symptomatic plants were positive for INSV. The other two plants were asymptomatic and tested negative for INSV. To further confirm the identity of this virus, total RNAs were isolated from symptomatic leave of begonia plants using TRIzol reagent (Invitrogen, Life Technologies Grand Island, NY) and amplified using reverse transcription (RT)-PCR analysis. A pair of primers was designed based on the consensus sequence of the N gene for a number of isolates retrieved from GenBank. These primers were INSV-F2286 (5'CCAAGCTCAACATGTTTAGC 3', nt positions 2286 to 2305 of AB109100) and INSV-R2604 (5'ACTGCATCTTGCCTATCCTT 3', nt positions 2664 to 2683 of AB109100). The expected amplification product of 398 bp was obtained, and was cloned into the vector pGEM-T Easy (Promega Corp., Madison, WI). Two clones were sequenced using the vector primer M13Forward. The sequences of these two clones were identical and the sequence was deposited in GenBank (Accession No. JX846907). BLAST analysis indicated that the sequence was 98 to 99% identical to INSV isolates from Japan (AB109100), the United States (D00914), and the Netherlands (X66972). To our knowledge, this is the first report of INSV infection in Begonia × hiemalis in Canada. This finding provides further evidence for the spread of the virus within North America. Further studies are required to determine the impact of INSV on the begonia industry in Canada and to determine viable management strategies, if necessary. Reference: (1) M. L. Daughtrey et al. Plant Dis. 81:1220, 1997.

Acute dietary zinc deficiency before conception compromises oocyte epigenetic programming and disrupts embryonic development

Recent findings show that zinc is an important factor necessary for regulating the meiotic cell cycle and ovulation. However, the role of zinc in promoting oocyte quality and developmental potential is not known. Using an in vivo model of acute dietary zinc deficiency, we show that feeding a zinc deficient diet (ZDD) for 3-5 days before ovulation (preconception) dramatically disrupts oocyte chromatin methylation and preimplantation development. There was a dramatic decrease in histone H3K4 trimethylation and global DNA methylation in zinc deficient oocytes. Moreover, there was a 3-20 fold increase in transcript abundance of repetitive elements (Iap, Line1, Sineb1, Sineb2), but a decrease in Gdf9, Zp3 and Figla mRNA. Only 53% and 8% of mature eggs reached the 2-cell stage after IVF in animals receiving a 3 and 5 days ZDD, respectively, while a 5 day ZDD in vivo reduced the proportion of 2-cells to 49%. In vivo fertilized 2-cell embryos cultured in vitro formed fewer (38%) blastocysts compared to control embryos (74%). Likewise, fewer blastocyst and expanded blastocyst were collected from the reproductive tract of zinc deficient animals on day 3.5 of pregnancy. This could be due to a decrease in Igf2 and H19 mRNA in ZDD blastocyst. Supplementation with a methyl donor (SAM) during IVM restored histone H3K4me3 and doubled the IVF success rate from 17% to 43% in oocytes from zinc deficient animals. Thus, the terminal period of oocyte development is extremely sensitive to perturbation in dietary zinc availability.

Meta-analysis demonstrates association of XRCC1 genetic polymorphism Arg399Gln with esophageal cancer risk in the Chinese population

We made a meta-analysis of the association between X-ray cross-complementing gene 1 (XRCC1) genetic polymorphism Arg399Gln and esophageal cancer (EC) risk. Statistical analysis was performed with the Review Manager version 4.2.8 software program and STATA version 11.0. We selected 16 case-control studies for this meta-analysis, including 3591 EC cases and 5752 controls. Overall, the Gln399 allele was not associated with EC risk, compared with the Arg399 allele in the populations included in the analysis. However, stratified analysis revealed that the Gln399 allele was associated with increased EC risk among the Chinese population in a recessive model [odds ratio (OR) = 1.42; 95% confidence interval (95%CI) = 1.07-1.90; P = 0.02 for heterogeneity] and by homozygote contrast (OR = 1.43; 95%CI = 1.05-1.96; P = 0.02 for heterogeneity), particularly for the tumor histology of squamous cell carcinoma (OR = 1.46; 95%CI = 1.10-1.95 for the recessive model and OR = 1.42; 95%CI = 1.03-1.95 for the homozygote contrast). We conclude that the XRCC1 Arg399Gln polymorphism has potential as a biomarker for EC susceptibility in the Chinese population, particularly for squamous cell carcinoma.