Imidacloprid is hydroxylated by Laodelphax striatellus CYP6AY3v2

Laodelphax striatellus (Fallén) is one of the most destructive pests of rice, and has developed high resistance to imidacloprid. Our previous work indicated a strong association between imidacloprid resistance and the overexpression of a cytochrome P450 gene CYP6AY3v2 in a L. striatellus imidacloprid resistant strain (Imid-R). In this study, a transgenic Drosophila melanogaster line that overexpressed the L. striatellus CYP6AY3v2 gene was established and was found to confer increased levels of imidacloprid resistance. Furthermore, CYP6AY3v2 was co-expressed with D. melanogaster cytochrome P450 reductase (CPR) in Spodoptera frugiperda 9 (SF9) cells. A carbon monoxide difference spectra analysis indicated that CYP6AY3v2 was expressed predominately in its cytochrome P450 (P450) form, which is indicative of a good-quality functional enzyme. The recombinant CYP6AY3v2 protein efficiently catalysed the model substrate P-nitroanisole to p-nitrophenol with a maximum velocity (V_max ) of 60.78 ± 3.93 optical density (mOD)/min/mg protein. In addition, imidacloprid itself was metabolized by the recombinant CYP6AY3v2/nicotinamide adenine dinucleotide 2'-phosphate reduced tetrasodium salt (NADPH) CPR microsomes in in vitro assays (catalytic constant (K_cat ) = 0.34 pmol/min/pmol P450, michaelis constant (K_m ) = 41.98 μM), and imidacloprid depletion and metabolite peak formation were with a time dependence. The data provided direct evidence that CYP6AY3v2 is capable of hydroxylation of imidacloprid and conferring metabolic resistance in L. striatellus.

[Effect of ShRNA targeting silencing of VTCN1 gene on nasopharyngeal carcinoma cells]

Objective:The aim of this study is to investigate the expression of VTCN1 in nasopharyngeal carcinoma cells and targeting silencing of VTCN1 gene by infected with lentiviral vector to inhibit the proliferation and invasion in nasopharyngeal carcinoma cells. Method:The VTCN1 expression level of different nasopharyngeal carcinoma cells was detected by RT-PCR and Western blotting, the cell lines of the most expression level were seleted to conduct the Subsequent experiments; The lentiviral vector of silenced VTCN1 was transfected into HNE2 cells with VTCN1 expression by lipofectamine 2000, and stable cell lines were screened. Then, the silencing efficiency was detect by RT-PCR and Western blotting; The proliferation and invasion abilities of nasopharyngeal carcinoma cells after VTCN1 gene silencing were detected by ckk-8 and Transwell invasion assay, respectively. The phosphorylation levels of JAK/STAT proteins in nasopharyngeal carcinoma cells with VTCN1 gene silencing were detected by Western blotting. Result:RT-PCR and Western blotting detected that stable transfection of VTCN1ShRNA into HNE2 cells resulted significantly declined expression of VTCN1 (P<0.05); The proliferation and invasion abilities of HNE2 cells were significantly decreased (P<0.05) and phosphorylation level of the JAK, STAT proteins were significantly decreased (P<0.05). Conclusion:VTCN1 ShRNA can effectively silence the expression of VTCN1, and significantly inhibits the proliferation and invasion of HNE2 cells. It may be related to down regulation of protein activity in JAK/STAT signaling pathway..

Association of time-varying clearance of nivolumab with disease dynamics and its implications on exposure response analysis

Nivolumab is a human monoclonal antibody that blocks the interaction between PD-1 programmed death-1 (PD-1) and its ligands, PD-L1 and PD-L2. Nivolumab demonstrated efficacy in clinical trials for various types of cancer. A time-varying clearance was identified for nivolumab. We show that the change of clearance over time is associated with the post-treatment effects: clearance decreases when disease status improves. This interaction between posttreatment effects and drug exposure may lead to a biased steep estimate of the exposure-response (E-R) relationship for efficacy. Under this scenario, simulations were performed to develop a proposed methodology to assess the causal effect of drug exposure upon clinical response. Data from nivolumab trials were subsequently used to verify the proposed methodology for E-R analysis. The results showed that E-R analysis results based on pharmacokinetic (PK) metrics derived from the first dose are more consistent with the true E-R or dose-response relationship than the steady-state PK metrics.

Association and meta-analysis of HLA and non-obstructive azoospermia in the Han Chinese population

The exact aetiology and pathogenesis of most non-obstructive azoospermia (NOA) are still unknown. The previous two genomewide association studies (GWASs) have identified three different loci within the HLA region for NOA in the Han Chinese population, including rs3129878, rs498422 and rs7194. To further validate the risk of three GWAS-linked loci for NOA, we conducted a case-control study of these three risk loci in an independent Han Chinese male population, with 603 NOA patients and 610 controls. Furthermore, we also performed a meta-analysis of five studies on these three NOA-risk loci. The case-control study strongly suggested a significant association between loci rs3129878, rs498422 and rs7194 and NOA (P = 6.75 × 10^-21 (OR = 2.2586), P = 0.0060 (OR = 1.4013) and P = 0.0128 (OR = 1.2626) respectively). Our meta-analyses also supported the susceptibility of these three risk loci to NOA (P < 0.01). The risk variants within the HLA region potentially have a strong effect on males at risk of NOA, and may serve as diagnostic markers for male infertility. However, considering genetic difference between different populations, future validating studies in larger independent samples and animal experiments are suggested.

Effect of Nanoparticles on the Survival and Development of Vitrified Porcine GV Oocytes

BACKGROUND: Some mammalian oocytes have been successfully cryopreserved by vitrification. However, the survival and developmental rate of vitrified oocytes is still low. The incorporation of nanoparticles into cryoprotectant (CPA) may improve the efficiency of vitrification by changing the properties of solutions.

MATERIALS AND METHODS

The toxicity of different concentrations of hydroxy apatite (HA), silica dioxide (SO₂), aluminum oxide (Al₂O₃) and titanium dioxide (TiO₂) nanoparticles (20 nm in diameter) to oocytes was tested and the toxicity threshold value of each nanoparticle was determined. Porcine GV oocytes were vitrified in optimized nano-CPA, and effects of diameter and concentration of nanoparticles on the survival rate and developmental rate of porcine GV oocytes were compared.

RESULTS

HA nanoparticles have demonstrated the least toxicity among four nanoparticles and the developmental rate of GV-stage porcine oocytes was 100% when its concentration was lower than 0.5%. By adding 0.1% HA into VS, the developmental rate of GV-stage porcine oocytes (22%) was significantly higher than other groups. The effect of vitrification in nano-CPA on oocytes was related to the concentration of HA nanoparticles rather than their size. By adding 0.05% HA nanoparticles (60nm in diameter), the developmental rate increased dramatically from 14.7% to 30.4%.

CONCLUSION

Nano-cryopreservation offers a new way to improve the effect of survival and development of oocytes, but the limitation of this technology shall not be ignored.

Blocking autophagy enhanced cytotoxicity induced by recombinant human arginase in triple-negative breast cancer cells

Depletion of arginine by recombinant human arginase (rhArg) has proven to be an effective cancer therapeutic approach for a variety of malignant tumors. Triple-negative breast cancers (TNBCs) lack of specific therapeutic targets, resulting in poor prognosis and limited therapeutic efficacy. To explore new therapeutic approaches for TNBC we studied the cytotoxicity of rhArg in five TNBC cells. We found that rhArg could inhibit cell growth in these five TNBC cells. Intriguingly, accumulation of autophagosomes and autophagic flux was observed in rhArg-treated MDA-MB-231 cells. Inhibition of autophagy by chloroquine (CQ), 3-methyladenine (3-MA) and siRNA targeting Beclin1 significantly enhanced rhArg-induced cytotoxic effect, indicating the cytoprotective role of autophagy in rhArg-induced cell death. In addition, N-acetyl-l-cysteine (NAC), a common antioxidant, blocked autophagy induced by rhArg, suggesting that reactive oxygen species (ROS) had an essential role in the cytotoxicity of rhArg. This study provides new insights into the molecular mechanism of autophagy involved in rhArg-induced cytotoxicity in TNBC cells. Meanwhile, our results revealed that rhArg, either alone or in combination with autophagic inhibitors, might be a potential novel therapy for the treatment of TNBC.

Alteration of coenzyme specificity of malate dehydrogenase from Streptomyces coelicolor A3(2) by site-directed mutagenesis

We describe here for the first time the alteration of coenzyme specificity of malate dehydrogenase (MDH) from Streptomyces coelicolor A3(2) (ScMDH). In the present study, we replaced four amino acid residues in the Rossmann fold (βB-αC) region of NADH-dependent ScMDH by site-directed mutagenesis with those of NADPH-dependent MDH (Glu42Gly, Ile43Ser, Pro45Arg, and Ala46Ser). The coenzyme specificity of the mutant enzyme (ScMDH-T4) was examined. Coenzyme specificity of ScMDH-T4 was shifted 2231.3-fold toward NADPH using kcat/Km(coenzyme) as the measurement of coenzyme specificity. Accordingly, the effect of the replacements on coenzyme specificity is discussed. Our work provides further insight into the coenzyme specificity of ScMDH.

Bile deficiency induces changes in intestinal Cl(-) and HCO3 (-) secretions in mice

AIMS

Biliary tract obstruction is a common clinical lesion. However, the effect of biliary tract obstruction on intestinal secretion is poorly understood. In this study, we made an investigation on intestinal HCO3 (-) and Cl(-) secretions in an experimental model of murine biliary duct ligation.

METHODS

Murine intestinal mucosal HCO3 (-) and Cl(-) secretions were examined in vitro in Ussing chambers by pH-stat and short-circuit current (Isc ) techniques. The mRNA and protein expressions of the cystic fibrosis transmembrane conductance regulator (CFTR) and the Na(+) -K(+) -2Cl(-) cotransporter (NKCC1) were analysed by real-time PCR, western blot and immunohistochemistry.

RESULTS

Basal Cl(-) secretion and forskolin-stimulated duodenal and jejunal mucosal HCO3 (-) and Cl(-) secretions in mice with common biliary duct ligation were markedly elevated, compared with controls (P < 0.05 and P < 0.01). Further experiments showed that basal Cl(-) secretion and forskolin-stimulated duodenal and jejunal mucosal HCO3 (-) and Cl(-) secretions in mice with external bile drainage were also markedly elevated. CFTRinh -172 inhibited forskolin-stimulated HCO3 (-) and Cl(-) secretions. The mRNA and protein expression levels of CFTR and NKCC1 in the intestinal mucosa with both biliary duct ligation and external bile drainage were markedly higher than those in controls (P < 0.001). Bile acid administration restored the changes in function and expression of CFTR and NKCC1 in the intestinal mucosa.

CONCLUSION

Bile deficiency in the intestine up-regulates the expressions of intestinal mucosal CFTR and NKCC1 and enhances intestinal mucosal HCO3 (-) and Cl(-) secretion capacity, which contributes to the understanding of intestinal physiological function for patients with biliary duct obstruction.

Association between FOXP3 polymorphisms and vitiligo in a Han Chinese population

BACKGROUND

Vitiligo is an autoimmune chronic depigmentation disorder caused by melanocyte loss. Previous studies found that CD4(+)CD25(+) regulatory T-cell (Treg) dysfunction was involved in the pathogenesis of vitiligo and that gene polymorphisms in forkhead box P3 (FOXP3) - a master regulator of Treg development and function - were associated with susceptibility to some autoimmune disorders. Therefore, we hypothesized that functional polymorphisms of the FOXP3 gene might be associated with vitiligo via dysregulation of Treg cells.

OBJECTIVES

To evaluate whether FOXP3 polymorphisms are associated with vitiligo risk.

MATERIAL AND METHODS

In this hospital-based case-control study of 682 patients with vitiligo and 682 vitiligo-free age- and sex-matched controls, we genotyped three single nucleotide polymorphisms (SNPs) of the FOXP3 gene - rs2232365, rs3761548 and rs5902434 - by performing polymerase chain reaction with sequence-specific primers (PCR-SSP).

RESULTS

Significantly increased vitiligo risk was associated with the rs2232365 GG [odds ratio (OR) 1·68, 95% confidence interval (CI) 1·17-2·39, P = 0·004] and rs3761548 AA (OR 1·82, 95% CI 1·10-3·01, P = 0·033) genotypes compared with the rs2232365 AA and rs3761548 CC genotypes. On combined analysis of these three variant alleles, we found that individuals carrying 2-6 variant alleles had significantly increased vitiligo risk (OR 1·34, 95% CI 1·08-1·66). This risk was more pronounced in the following subgroups: age > 20 years, male sex, active vitiligo, nonsegmental vitiligo and other accompanying autoimmune diseases.

CONCLUSIONS

FOXP3 gene polymorphisms contributed to vitiligo risk in a Han Chinese population.

A Reassessment of Virulence Phenotypes of Soybean Cyst Nematode (Heterodera glycines) in China with HG Typing Method

Soybean cyst nematode, Heterodera glycines Ichinohe, is the most destructive pest of soybean (Glycine max) worldwide, including China. H. glycines virulence phenotypes can be described in two ways. One is the race determination test that uses four soybean lines to categorize H. glycines into 16 "races" (3). The HG type designation is similar, but avoids the implications of the term "race" and includes seven soybean lines rather than four (2). In China, previous data revealed the occurrence of nine H. glycines races including races 1 through 7, 9, and 14, whereas HG types have not been recorded (1). The objective of this study was to reassess virulence phenotypes of H. glycines in China by means of HG types. In 2011 and 2012, 10 SCN populations from the primary soybean production regions of China were identified as six races (races 1, 2, 3, 4, 5, 6, and 14) with the race test scheme (3) and were cultured on a H. glycines-susceptible soybean cultivar. In 2013, seven indicator soybean lines (PI 548402, PI 88788, PI 90763, PI 437654, PI 209332, PI 89772, and PI 548316) plus the susceptible standard soybean "Lee74" were used to determine the HG types of these populations following standardized procedures (2) with some modification in a growth chamber set at 28°C under 16-h days. After 30 days, females were extracted from roots and collected, and a female index was calculated for each indicator line (2,3). The average number of females on Lee74 was more than 100 in all the tests. Eight HG types were identified in the populations tested: HG type 0 (race 3), HG type 7 (race 3 or 6), HG type 2.7 (race 1 or 5), HG type 5.7 (race 3), HG type 1.3.7 (race 14), HG type 2.5.7 (race 1), HG type 1.2.5.7 (race 2), and HG type 1.2.3.5.7 (race 4). To our knowledge, this is the first report of H. glycines HG types in China, which will contribute to development of management strategies implementing the use of resistant cultivars. This work was supported by the Special Fund for Agro-scientific Research in the Public Interest 200903040-03 and the China Agriculture Research System CARS-04. References: (1) W. G. Lu et al. Agr. Sci. China 5:615, 2006. (2) T. L. Niblack et al. J. Nematol. 34:279, 2002. (3) R. D. Riggs and D. P. Schmitt. J. Nematol. 20:392, 1988.

Iatrogenic renovascular injuries treated by transarterial embolization

BACKGROUND

Renal vascular injury may be secondary to blunt or penetrating trauma, iatrogenic injuries or spontaneously with or without underlying pathology. The study aims to evaluate the effectiveness and safety of transarterial embolization (TAE) for the treatment of iatrogenic renovascular injuries (IRVIs).

PATIENTS AND METHODS

Thirty-six patients (27 males, 9 females, aged 14-79 years) with IRVIs were treated with TAE. Preprocedure computed tomography (CT) and/or ultrasound (US) and/or digital subtraction angiography (DSA) confirmed the presence of IRVIs in all 36 patients. The embolic materials include metallic coils, polyvinyl alcohol particles (PVA), gelfoam and n-butyl cyanoacrylate (NBCA) iodized oil mixture were used. The results of the embolization procedure were recorded. Patients were followed up, and complications of the procedure were noted.

RESULTS

A total of 40 embolization procedures were performed in 36 patients, and technical success was achieved in all procedures. Medical successes were achieved in 32 (89%) patients. Postembolization syndrome (back pain and fever) were detected in 12 patients (22%). Perirenal abscess was seen in one patient (3%). Puncture-site bleeding, nontarget embolization, decrease in renal function, and arterial hypertension were not detected in any of the patients.

CONCLUSIONS

TAE is an effective, minimally invasive treatment method for IRVIs. Therefore, TAE should be the first preferred treatment modality.

A simple novel technique for heterotopic intestinal transplantation in mice

The murine heterotopic intestinal transplant model is of particular value for addressing the unique immune response in the gut and addressing the underlying immune mechanism during transplantation. Anastomotic stenosis, anastomotic bleeding, and septic shock continue to hamper procedures and plague the success. In this study, we assessed a refined technique designed to improve the success of heterotopic intestinal transplant in mice. Important factors in our refined technique included (1) a refined procedure for graft portal vein preparation, (2) a novel procedure for graft exteriorization, and most importantly (3) a knotless suturing technique designed to allow the surgeon to alter the size of the anastomosis, thus reducing anastomotic bleeding and stenosis rate. Our refined knotless method improved recipient survival to 67.5% when compared to the standard technique (53.8%). In comparison to standard knot suturing technique, which had an anastomotic stenosis rate of 8.3%, the knotless suturing technique significantly reduced the rate of anastomotic stenosis to only 2.4%. Anastomotic bleeding presented in the knotless technique in only 1.2%, whereas it presented in 6.2%, of mice in the standard technique (P < .05). This refined knotless technique offers an easy and effective method for murine heterotopic intestinal transplantation.

Patellar tendon morphology in volleyball athletes with and without patellar tendinopathy

Appropriate management of patellar tendinopathy requires distinguishing between inflammatory and degenerative conditions, often difficult because tendon thickening can be a normal or pathological adaptation, and micromorphology is not observable on clinical imaging. The purpose of this study was to quantitatively examine patellar tendon micro- and macromorphology in volleyball athletes and relate those findings to reported symptoms. Longitudinal ultrasound images of proximal and distal patellar tendons were acquired from 84 male elite volleyball athletes (44 symptomatic, 40 asymptomatic) and 10 asymptomatic nonathlete controls. Micromorphology was determined using two-dimensional Fast Fourier Transform analysis providing a discriminating peak spatial frequency parameter (PSF). Macromorphology (patellar tendon thickness) was measured using Image J software. All athletes regardless of symptoms had thicker proximal tendons compared to nonathletes, suggesting a normal adaptation to training loads. However, symptomatic athletes demonstrated lower PSF than asymptomatic athletes and nonathletes at the proximal tendon, suggesting greater collagen disorganization, and tendon degeneration rather than inflammation. Only symptomatic athletes had thicker distal tendons than nonathletes, but there was no difference in PSF distally. Diagnostic ultrasound enhances the understanding of the micromorphology of patellar tendons, supporting the rationale for management that remodels the degenerated tendon instead of treating inflammation.

Ab initio-based double many-body expansion potential energy surface for the first excited triplet state of the ammonia molecule

A global single-sheeted double many-body expansion potential energy surface is reported for the first excited triplet state of NH(3). It employs an approximate cluster expansion of the molecular potential that utilizes previously reported functions of the same family for the triatomic fragments. Four-body energy terms have been calibrated from extensive accurate ab initio data so as to reproduce the main features of the title system. A new switching function formalism has been reported to approximate the true multisheeted nature of NH(3)((3)A(2) ('')) potential energy surface, thus allowing the correct behavior at the NH(2)((2)A(")) + H((2)S) and NH(2)((4)A(")) + H((2)S) dissociation limits. The resulting fully six-dimensional potential energy function reproduces the correct symmetry under the permutation of identical atoms, and predicts the correct behavior at all dissociation channels while providing a realistic representation at all interatomic separations. The major attributes of the NH(3) double many-body expansion potential energy surface have also been characterized, and found to be in good agreement, both with the calculated ones from the raw ab initio energies and the theoretical results available in the literature.