Photodegradation of diclofenac in seawater by simulated sunlight irradiation: The comprehensive effect of nitrate, Fe(III) and chloride

Diclofenac is one of the most frequently detected pharmaceuticals in various aquatic environments. The photodegradation of diclofenac in the absence/presence of nitrate, Fe(III) and chloride, especially their interactions, were systematically studied. Under the study conditions, photodegradation rate was decreased with increasing nitrate, Fe(III) and chloride concentrations. Nitrate has an synergistic action for Fe(III). Nitrate and chloride have antagonistic effect. An antagonistic action is present between nitrate, Fe(III) and chloride. Moreover, a simple linear model which very well describes the results is given.

Down-regulation of miR-655-3p predicts worse clinical outcome in patients suffering from hepatocellular carcinoma

OBJECTIVE

MiR-655-3p has been reported to play important roles in tumor initiation, development, and metastasis in several cancers. This study aimed to assess the potential role of miR-655-3p in the pathogenesis of hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

The expression levels of miR-655-3p in HCC tissues were detected by qPCR. The relationship between clinicopathologic characteristics and miR-655-3p was analyzed by chi-square test. Kaplan-Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome.

RESULTS

miR-655-3p was significantly down- regulated in HCC tissues compared to normal adjacent liver tissues (p < 0.01). Low miR-655-3p expression was observed to be closely correlated with positive microvascular invasion, advanced tumor stage and lymph node metastasis (p < 0.05, respectively). The results of Kaplan-Meier analysis showed that patients with high miR-655-3p expression lived shorter than those with low miR-655-3p expression (Log-rank test, p = 0.0002). Multivariate analysis revealed that miR-655-3p was an independent risk factor for HCC (HR=1.533, 95% CI: 0.988-3.891; p = 0.002).

CONCLUSIONS

Our data showed that low expression of miR-655-3p was associated with significant characteristics of patients with HCC, and it could function as a potential unfavorable prognostic biomarker.

Charge-Dependent Directed Flow in Cu+Au Collisions at sqrt[s_{NN}]=200 GeV

We present the first measurement of charge-dependent directed flow in Cu+Au collisions at sqrt[s_{NN}]=200  GeV. The results are presented as a function of the particle transverse momentum and pseudorapidity for different centralities. A finite difference between the directed flow of positive and negative charged particles is observed that qualitatively agrees with the expectations from the effects of the initial strong electric field between two colliding ions with different nuclear charges. The measured difference in directed flow is much smaller than that obtained from the parton-hadron-string-dynamics model, which suggests that most of the electric charges, i.e., quarks and antiquarks, have not yet been created during the lifetime of the strong electric field, which is of the order of, or less than, 1  fm/c.

Temperature and size-dependent Hamaker constants for metal nanoparticles

Theoretical values of the Hamaker constant have been calculated for metal nanoparticles using Lifshitz theory. The theory describes the Hamaker constant in terms of the permittivity of the interacting bodies. Metal nanoparticles exhibit an internal size effect that alters the dielectric permittivity of the particle when its size falls below the mean free path of the conducting electrons. This size dependence of the permittivity leads to size-dependence of the Hamaker constant for metal nanoparticles. Additionally, the electron damping and the plasma frequency used to model the permittivity of the particle exhibit temperature-dependence, which lead to temperature dependence of the Hamaker constant. In this work, both the size and temperature dependence for gold, silver, copper, and aluminum nanoparticles is demonstrated. The results of this study might be of interest for studying the colloidal stability of nanoparticles in solution.

[Relationship between full flowering stages of anemophilous and ligneous plants and consultation rate of allergic rhinitis]

Objective:The aim of this study is to investigate the climatic changes on spring phenology impacting on the consultation rate of patients with allergic rhinitis.Method:We analyzed the periods of full flowering stages of 15 kinds of flowers in Beijing from 2013 to 2014,and the number of patients with allergic rhinitis in the outpatient clinic of Otolaryngology Department of Peking University Third Hospital in the same time.The correlation test, analysis of variance and rank sum test were used to investigate the inherent laws and associations between the full flowering stages and the ratio of patients with allergic rhinitis.Result:①Between 2013 and 2014,the early and middle April were the full flowering stages of Platycladus orientalis,Salix matsudana, Fraxinus chinensis,Elms and Birches.The number of patients with allergic rhinitis in outpatient clinic elevated obviously in this period.②There were overlaps of full flowering stages among different plants.During periods in which three or more kinds of pollens in full flowering stages,the consultation rate of patients with allergic rhinitis is higher than less overlaping flower period.The difference was statistically significant(F value were -2.281,-2.964 respectively, P <0.05).Also,there were obvious positive linear correlations between the number of overlap of different pollens and the consultation rate of patients with allergic rhinitis in in 2013 and 2014(r=0.957, 0.964 respectively).Conclusion:During the overlaping flower periods,there was a higher consultation rate of patients with allergic rhinitis.In prevention and treatment of allergic rhinitis,the overlapping effect of full flowering stages of different pollens should be taken into account.Upgrade the alarm level will reduce the incidence of AR and the degree of allergic rhinitis episodes.

Measurement of the Transverse Single-Spin Asymmetry in p^{↑}+p→W^{±}/Z^{0} at RHIC

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at sqrt[s]=500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au+Au Collisions at RHIC

We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from sqrt[s_{NN}]=7.7 to 200 GeV. The third harmonic v_{3}^{2}{2}=⟨cos3(ϕ_{1}-ϕ_{2})⟩, where ϕ_{1}-ϕ_{2} is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη=η_{1}-η_{2}. Nonzero v_{3}^{2}{2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v_{3}^{2}{2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v_{3}^{2}{2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v_{3}^{2}{2} for central collisions shows a minimum near sqrt[s_{NN}]=20  GeV.

Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au+Au Collisions at √[sNN]=200 GeV

We present high precision measurements of elliptic flow near midrapidity (|y|<1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy √[sNN]=200  GeV. We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2.

Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in p^{↑}+p at sqrt[s]=200 GeV

We report the observation of transverse polarization-dependent azimuthal correlations in charged pion pair production with the STAR experiment in p^{↑}+p collisions at RHIC. These correlations directly probe quark transversity distributions. We measure signals in excess of 5 standard deviations at high transverse momenta, at high pseudorapidities η>0.5, and for pair masses around the mass of the ρ meson. This is the first direct transversity measurement in p+p collisions.

Azimuthal Anisotropy in U+U and Au+Au Collisions at RHIC

Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v_{2}{2} and v_{2}{4}, for charged hadrons from U+U collisions at sqrt[s_{NN}]=193  GeV and Au+Au collisions at sqrt[s_{NN}]=200  GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v_{2}{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v_{2} vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

Interleukin-10 gene promoter polymorphism and risk of liver cirrhosis

We conducted a hospital-based case-control study to assess the association between IL-10-592 A/C, IL-10-819 C/T, and IL-10-1082 A/G polymorphisms and the risk of liver cirrhosis in a Chinese population. This 1:1-matched case-control study included 192 patients from the Chinese PLA General Hospital. Genotypes of IL-10-592 A/C, IL-10-819 C/T, and IL-10-1082 A/G were detected by polymerase chain reaction amplification-restriction fragment length polymorphism analysis. Conditional regression analysis showed that individuals carrying the IL-10-1082 G allele had an only slightly increased risk of liver cirrhosis, with an adjusted odds ratio (95% confidence interval) of 2.14 (0.97-1.68). However, we did not identify a significant association between polymorphisms in IL-10-592 A/C and IL-10-819 C/T and the risk of liver cirrhosis. These findings may provide important clues for future studies of early detection screening of liver cirrhosis.

Prospective controlled study of the safety and oncological outcomes of ELAPE procure with definitive anatomic landmarks versus conventional APE for lower rectal cancer

BACKGROUND

The use of extra-levator abdominoperineal resection (ELAPE) procedure for lower rectal cancer is controversial. It is unclear whether the ELAPE procedure could improve surgical safety and lead to better oncological outcomes.

METHODS

Sixty-nine lower rectal cancer patients who underwent ELAPE (36 cases) or conventional abdominoperineal resection (APE; 33 cases) between June 2011 and February 2013 were prospectively investigated. Clinicopathological variables including blood loss, intraoperative perforation (IOP) rate, circumferential resection margin (CRM) involvement, lymph node harvest, the postoperative complications, urinary and sexual function, quality of life (QOL), local recurrence rate and survival were recorded and compared.

RESULTS

Blood loss (P = 0.021), perineal wound complication (P = 0.039), IOP rate (P = 0.028), local recurrence (P = 0.034) were significantly less frequent in the ELAPE group. There was greater CRM involvement in the conventional APE group but no statistical difference between the two groups. Urinary function, sexual function and QOL were not significantly different between the two groups. Overall survival and progression-free survival were not significantly different between two groups, even when survival was analyzed according to TNM stage, T stage, N stage, and with or without neoadjuvant chemoradiotherapy. In patients who underwent ELAPE there was no statistical difference in postoperative complications between younger and elderly patients (age ≥60).

CONCLUSIONS

ELAPE procedure with definitive anatomic landmarks demonstrated surgical safety and decreased local recurrence for lower rectal cancer patients including the elderly, but there were no survival improvements in compared to conventional APE procedure.

Surgical management of biliary cystadenoma and cystadenocarcinoma of the liver

Biliary cystadenoma (BCA) and biliary cystadenocarcinoma (BCAC) are rare biliary duct neoplasms. This study investigated reasonable management strategies of cystic neoplasms in the liver. Charts of 39 BCA/BCAC patients (9 males, 30 female; median age 53.74 ± 14.50 years) who underwent surgery from January 1999 to December 2009 were reviewed retrospectively. Cyst fluid samples of 32 BCA/BCAC patients and 40 simple hepatic cyst patients were examined for the tumor markers carbohydrate associated antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA). The most frequent symptoms were abdominal pain (N = 10), abdominal mass (N = 7), abdominal distension (N = 4), jaundice (N = 2), and fever (N = 3); the remaining patients showed no clinical symptoms. Liver resection (N = 17) or enucleation (N = 22) was performed in the 39 patients. Ultimately, 35 patients were diagnosed with intrahepatic BCA and four patients were diagnosed with BCAC. The median CA19-9 level was significantly higher in BCA/BCAC patients than in simple hepatic cyst patients. The median CEA levels in BCA/BCAC patients and controls were 6.83 ± 2.43 and 4.21 ± 2.91 mg/L, respectively. All symptoms were resolved after surgery, and only one BCAC patient showed recurrence. The incidence of intrahepatic cystic lesions was 1.7%. Increased CA19-9 levels in the cyst fluid is a helpful marker for distinguishing BCA/BCAC from common simple cysts. The presence of coarse calcifications is suggestive of BCAC. Complete surgical removal of these lesions yielded satisfying long-term outcomes with a very low recurrence rate.

Growth kinetics of calcium fluoride at high supersaturation in a fluidized bed reactor

Crystallization process in a fluidized bed reactor (FBR) has been regarded as an environmentally friendly technology for the removal and recovery of fluoride from industrial wastewater. The growth kinetics of calcium fluoride at high supersaturation was studied for design, control, and operation of an FBR. The main variables, including supersaturation, superficial velocity, pH value, and particle size of seed that influenced the crystal growth were investigated. Then, a growth model was used to predict the linear growth rate of calcium fluoride at a high influent concentration of fluoride. The pressure difference in the FBR was used as a feature to characterize the growth rate of calcium fluoride. The aggregation and adsorption between seeds and fine particles were proven to be a possible mechanism for growth of calcium fluoride.

Screening of genes related with intervertebral disc disease by dynamic differential interaction network analysis

AIM

Gene expression profiles for intervertebral disc (IVD) cells treated with different osmolarities were compared to identify key genes associated with intervertebral disc diseases.

MATERIALS AND METHODS

Microarray data was downloaded from Gene Expression Omnibus (GEO) database and pre-processed using package of R. Gene co-expression was determined with Pearson correlation coefficient. Interaction networks were established with the protein-protein interaction (PPI) information obtained from Human Protein Reference Database (HPRD database) for the two conditions: isosmoticity and hyperosmosis, and then a comparative analysis was done to identify disease-related genes. The functional annotation was performed for these genes using network ontology analysis (NOA), which also confirmed the effectiveness of this method.

RESULTS

A total of 45 feature genes were obtained through comparing 7 samples treated under isosmotic conditions and 9 high osmotic conditions. Biological processes and molecular functions were then revealed by NOA.

CONCLUSIONS

A range of disease-related genes were obtained, which might serve as the potential biomarkers or drug targets. More works are needed to further elucidate their roles in the development of intervertebral disc diseases like intervertebral disc herniation.

Optimal conditions for "heat-conduct effect" in liver tissue during radiofrequency ablation

AIM

This study was conducted to optimize the "heat-conduct effect" to increase the efficacy of radiofrequency ablation (RFA) in the treatment of liver tumors.

METHODS

To simulate the "heat-conduct effect" caused by RFA, isolated pig livers were heated by an inserted metal tube through which water with different incoming temperatures was passed. The tissue temperature was measured within 5- and 10-mm radiuses. Further, changes in color and morphology of the tissue were recorded.

RESULTS

Using an incoming temperature of 70 °C, the effective ablation radius of 5 mm was achieved within 10 min. To expand the effective radius to 10 mm, the tube temperature needed to be maintained at above 80 °C for 40 min; alternatively, the tube temperature above 90 °C and heating time of 25 min were also sufficient.

CONCLUSION

To achieve the complete ablation in isolated liver within the 10 mm radius by "heat-conduct effect", the temperature of the heating center should be maintained above 80 - 90 °C with the exposure time of 25-40 min.

[Macrophage migration inhibitory factor in mud crab Scylla paramamosain: molecular cloning, expression profiles in various tissues and under Vibrio challenge]

As one of the first found cytokines, macrophage migration inhibitory factor (MIF) plays AN important role in several physiological processes in crabs. In this study, a full-length MIF cDNA (GenBank accession number: JX131610) from mud crab Scylla paramamosain (Sp) was cloned based on a sequence of S. paramamosain cDNA library. The full length of SpMIF was 734 bp consisting of a 363 bp open reading frame encoding the SpMIF, a 120 amino acid peptide chain. The molecular weight of SpMIF was 13.46 kDa with the pI of 6.82. The alignment analysis showed that SpMIF appeared to be closely related to the counterpart from crab Eriocheir sinensis (68%). Quantitative real-time PCR analysis revealed that SpMIF was highly expressed in hepatopancreas and hemocytes. In addition, the expression level of SpMIF was increased significantly after a 6-h challenge by Vibrio parahaemolyticus (4.00 x 10(6) CFU/mL), peaked at 8 h, and then declined to the common level in 48 h. This data indicated that SpMIF was cloned successfully, and suggested that it participated in the immune system of mud crabs.

Surface anatomical profile of the cerebral cortex in obsessive-compulsive disorder: a study of cortical thickness, folding and surface area

BACKGROUND

Studying the distribution of anatomical abnormalities over the entire cortical surface can help to identify key neural circuits implicated in generating symptoms of neuropsychiatric disorders. There is a significant inconsistency among studies investigating the neuroanatomy of obsessive-compulsive disorder (OCD) because of the confounding influence of co-morbid depression and medication use and the lack of unbiased estimation of whole-brain morphometric changes. It is also unknown whether the distinct surface anatomical properties of thickness, surface area and gyrification, which collectively contribute to grey matter volume (GMV), are independently affected in OCD. Method The cortical maps of thickness, gyrification and surface areal change were acquired from 23 unmedicated OCD patients and 20 healthy controls using an unbiased whole-brain surface-based morphometric (SBM) method to detect regional changes in OCD. Subcortical structures were not assessed in this study.

RESULTS

Patients showed a significant increase in the right inferior parietal cortical thickness. Significant increases in gyrification were also noted in the left insula, left middle frontal and left lateral occipital regions extending to the precuneus and right supramarginal gyrus in OCD. Areal contraction/expansion maps revealed no significant regional differences between the patients and controls. In patients, gyrification of the insula significantly predicted the symptom severity measured using Yale-Brown Obsessive-Compulsive Scale (YBOCS).

CONCLUSIONS

An alteration in the cortical surface anatomy is an important feature of OCD seen in unmedicated samples that relates to the severity of the illness. The results underscore the presence of a neurodevelopmental aberration underlying the pathophysiology of OCD.

Fabrication of hybrid nanostructured arrays using a PDMS/PDMS replication process

In the study, a novel and low cost nanofabrication process is proposed for producing hybrid polydimethylsiloxane (PDMS) nanostructured arrays. The proposed process involves monolayer self-assembly of polystyrene (PS) spheres, PDMS nanoreplication, thin film coating, and PDMS to PDMS (PDMS/PDMS) replication. A self-assembled monolayer of PS spheres is used as the first template. Second, a PDMS template is achieved by replica moulding. Third, the PDMS template is coated with a platinum or gold layer. Finally, a PDMS nanostructured array is developed by casting PDMS slurry on top of the coated PDMS. The cured PDMS is peeled off and used as a replica surface. In this study, the influences of the coating on the PDMS topography, contact angle of the PDMS slurry and the peeling off ability are discussed in detail. From experimental evaluation, a thickness of at least 20 nm gold layer or 40 nm platinum layer on the surface of the PDMS template improves the contact angle and eases peeling off. The coated PDMS surface is successfully used as a template to achieve the replica with a uniform array via PDMS/PDMS replication process. Both the PDMS template and the replica are free of defects and also undistorted after demoulding with a highly ordered hexagonal arrangement. In addition, the geometry of the nanostructured PDMS can be controlled by changing the thickness of the deposited layer. The simplicity and the controllability of the process show great promise as a robust nanoreplication method for functional applications.

Effects of various salinities on Na(+)-K(+)-ATPase, Hsp70 and Hsp90 expression profiles in juvenile mitten crabs, Eriocheir sinensis

Eriocheir sinensis is a euryhaline crab migrating from sea to freshwater habitats during the juvenile stage. We used quantitative real-time polymerase chain reaction (qRT-PCR) to investigate the gene expression profile of Na(+)-K(+)-ATPase, Hsp70 (heat shock protein 70) and Hsp90 in megalopa exposed to salinities of 0, 2, 5, 10, and 15 parts per thousand. Both low and high salinities markedly stimulated expression of Na(+)-K(+)-ATPase, Hsp70 and Hsp90 genes of Chinese mitten crab megalopa; salinity had different effects on Na(+)-K(+)-ATPase, Hsp70 and Hsp90 levels depending on the duration of salinity stress, implying that Na(+)-K(+)-ATPase, Hsp70 and Hsp90 may play an important role in salinity tolerance in this crab species.

Influences of oxygen pressure on optical properties and interband electronic transitions in multiferroic bismuth ferrite nanocrystalline films grown by pulsed laser deposition

Bismuth ferrite (BiFeO(3)) nanocrystalline films with the crystalline size of 27-40 nm have been grown on c-sapphire substrates under various oxygen pressures of 1 × 10(-4) to 1 Pa by pulsed laser deposition. The X-ray diffraction spectra show that the films are polycrystalline and present the pure rhombohedral phase. It was found that the Raman-active phonon mode E(TO1) shifts towards a higher energy side from 74 to 76 cm(-1) with increasing oxygen pressure, indicating a larger tensile stress in the films deposited at higher oxygen pressure. The X-ray photoelectron spectroscopy analysis suggests that the concentrations of both Fe(2+) ions and oxygen vacancies in the BiFeO(3) films increase with decreasing oxygen pressure. Moreover, the dielectric functions in the photon energy range of 0.47-6.5 eV have been extracted by fitting the transmittance spectra with the Tauc-Lorentz dispersion model. From the transmittance spectra, the fundamental absorption edge is observed to present a redshift trend with increasing the temperature from 8 to 300 K. Note that the optical band gap (E(g)) decreases with increasing the temperature due to the electron-phonon interactions associated with the interatomic distance in the BiFeO(3) films. However, the E(g) decreases from 2.88 to 2.78 eV with decreasing oxygen pressure at 8 K, which can be attributed to the increment of oxygen vacancies leading to the formation of some impurity states between the valence and conduction band. It can be concluded that the oxygen pressure during the film fabrication has the significant effects on microstructure, optical properties, and electronic band structure modification of the BiFeO(3) films.

Three-dimensional surface reconstruction of diatomaceous frustules

Single-celled diatoms have attracted much attention due to their delicate nanostructures and wide applications in photonics, biology, nanofluidics, drug delivery, and so on. Three-dimensional (3D) surface reconstruction of diatoms has profound significance both in theory and in applications. The scanning electron microscope (SEM) stereo imaging technique was used to reconstruct the surface features of the diatomaceous frustules to quantitatively evaluate specimens. Geometrical parameters such as volume and area were given based on the reconstructed 3D image. This approach provides a simple and efficient way to measure the morphological parameters of diatoms at nanometer scale in three dimensions.

Effect of aging on optical properties of bimetallic sensor chips

Bimetallic silver/gold sensor chips are attractive since they combine the advantages of both silver and gold layers. Optical properties of the bimetallic sensor chips show significant aging effects. Surface plasmon resonance (SPR) curves were produced on an SPR device and the time dependence of aging on SPR curves was studied. The results show that resonance angle and full width at half maximum (FWHM) of response curves increase with the aging time after film deposition. The performance of the sensor chips in terms of intrinsic sensitivity (IS) degrades with aging time. The underlying mechanism of the aging effect is explained as the growth of a silver oxide layer between gold and silver during the aging process.

The fabrication of high-aspect-ratio, size-tunable nanopore arrays by modified nanosphere lithography

A modified nanosphere lithographic process for producing high aspect ratio and size-tunable nanopore arrays is described. A self-assembled bilayer nanosphere template is created as an etch mask for a deep reactive ion etching (DRIE) process. The size of the nanopores is tuned by reducing the diameter of the top-layer nanospheres using oxygen etching. Nanopore arrays with mean in-plane widths ranging from 120.9 to 343 nm and depths up to 2 microm have been achieved. This process offers excellent control over the nanopore size, aspect ratio and pitch of the fabricated nanostructures. The approach can also be extended to fabricate nanopore arrays of a wide range of materials.

Ablation of Stat3 by siRNA alters gene expression profiles in JEG-3 cells: a systems biology approach

Control of inflammation at the maternal-fetal interface is a critical element in mammalian pregnancy. Previous work from our laboratory has shown that Stat3 may be a placental mediator involved in maintaining immunologic homeostasis at the maternal-fetal interface. The aim of the current study is to further elucidate the role of Stat3 in response to inflammation. As ablation of Stat3 in mice results in embryonic lethality, we evaluated the role of Stat3 in vitro using an siRNA approach. Trophoblast-like JEG-3 cells were transfected with an siRNA construct specific to Stat3. Experimental and control cells were exposed to conditioned medium from PHA-activated peripheral blood mononuclear cells and incubated for 45 min. Cells were then collected and RNA isolated for transcriptional profiling using human Affymetrix U133 plus 2.0 GeneChips. Differences in gene expression between control and Stat3-ablated cells were evaluated using conventional statistical methods. Fifty-two genes were detected as up-regulated in conditioned medium in both mock transfected and in Stat3 siRNA transfected JEG-3 cells. Two genes (EPAS1 and RASGEF1B) were up-regulated only in cells transfected with negative control siRNA, while 36 genes were up-regulated only in cells transfected with Stat3 siRNA. Sixty genes were differentially expressed between Stat3 siRNA transfected cells relative to mock transfected cells both in basal and conditioned medium. These included 31 genes up-regulated with Stat3 siRNA transfected cells and 29 genes down-regulated with Stat3 siRNA. Eleven genes were differentially expressed only in basal medium. Seven of these were up-regulated in the presence of Stat3 siRNA and four were down-regulated. Nine genes were differentially expressed only in conditioned medium. Six of these were up-regulated and three down-regulated in the presence of Stat3 siRNA. Off-target effects were excluded in a second set of experiments in which Stat3 mRNA was targeted at a different site and quantitative real-time PCR performed on selected genes derived from the microarray analysis. While some of the genes that showed differential expression between Stat3-ablated cells and mock transfected controls were genes typically associated with immune response (e.g., CCR7 and IRAK1), in silico modeling of the microarray data also revealed complex networks of signaling molecules and molecules associated with cellular metabolism previously seen in transcription factor ablation in model organisms. We conclude thus: Stat3 controls a specific gene set in trophoblast-like JEG-3 cells. While some differentially expressed genes and in silico models of their functions are consistent with the hypothesis that Stat3 plays a role in regulating inflammation, Stat3-mediated response to inflammation appears to also involve complex homeostatic adaptations of a non-immunologic nature.

Functional involvement of protein kinase C-betaII and its substrate, myristoylated alanine-rich C-kinase substrate (MARCKS), in insulin-stimulated glucose transport in L6 rat skeletal muscle cells

AIMS/HYPOTHESIS

Insulin stimulates phosphorylation cascades, including phosphatidylinositol-3-kinase (PI3K), phosphatidylinositol-dependent kinase (PDK1), Akt, and protein kinase C (PKC). Myristoylated alanine-rich C-kinase substrate (MARCKS), a PKCbetaII substrate, could link the effects of insulin to insulin-stimulated glucose transport (ISGT) via phosphorylation of its effector domain since MARCKS has a role in cytoskeletal rearrangements.

METHODS

We examined phosphoPKCbetaII after insulin treatment of L6 myocytes, and cytosolic and membrane phosphoMARCKS, MARCKS and phospholipase D1 in cells pretreated with LY294002 (PI3K inhibitor), CG53353 (PKCbetaII inhibitor) or W13 (calmodulin inhibitor), PI3K, PKCbetaII and calmodulin inhibitors, respectively, before insulin treatment, using western blots. ISGT was examined after cells had been treated with inhibitors, small inhibitory RNA (siRNA) for MARCKS, or transfection with MARCKS mutated at a PKC site. MARCKS, PKCbetaII, GLUT4 and insulin receptor were immunoblotted in subcellular fractions with F-actin antibody immunoprecipitates to demonstrate changes following insulin treatment. GLUT4 membrane insertion was followed after insulin with or without CG53353.

RESULTS

Insulin increased phosphoPKCbetaII(Ser660 and Thr641); LY294002 blocked this, indicating its activation by PI3K. Insulin treatment increased cytosolic phosphoMARCKS, decreased membrane MARCKS and increased membrane phospholipase D1 (PLD1), a protein regulating glucose transporter vesicle fusion resulted. PhosphoMARCKS was attenuated by CG53353 or MARCKS siRNA. MARCKS siRNA blocked ISGT. Association of PKCbetaII and GLUT4 with membrane F-actin was enhanced by insulin, as was that of cytosolic and membrane MARCKS. ISGT was attenuated in myocytes transfected with mutated MARCKS (Ser152Ala), whereas overproduction of wild-type MARCKS enhanced ISGT. CG53353 blocked insertion of GLUT4 into membranes of insulin treated cells.

CONCLUSIONS/INTERPRETATION

The results suggest that PKCbetaII is involved in mediating downstream steps of ISGT through MARCKS phosphorylation and cytoskeletal remodelling.

Molecular cloning and mRNA expression profiling of the first specific jasmonate biosynthetic pathway gene allene oxide synthase from Hyoscyamus niger

In the endeavor to enhance the production of pharmaceutically valuable tropane alkaloids including hyoscyamine and scopolamine in Hyoscyamus niger, methyl jasmonate (MeJA) showed significant stimulation both in tropane biosynthetic pathway enzymes activities and tropane alkaloids yields. Therefore it was speculated that genetic engineering of jasmonate biosynthetic pathway might enhance the endogenous jasmonate concentration, followed by stimulating the production of tropane alkaloids. Herein a full-length cDNA encoding allene oxide synthase (AOS, EC 4.2.1.92), the first committed step enzyme in jasmonate biosynthetic pathway was reported (named HnAOS, GenBank accession: EF532599). HnAOS was a novel member of the cytochrome P450 (CYP74A) subfamily. Real-time quantitative PCR analysis showed that HnAOS mRNA accumulated mainly in stems, and responded significantly to wounding or methyl jasmonate.

RNA interference-mediated silencing of the polo-like kinase 1 gene enhances chemosensitivity to gemcitabine in pancreatic adenocarcinoma cells

Gemcitabine is the first-line chemotherapeutic agent for advanced adenocarcinoma of the pancreas; however, chemoresistance to gemcitabine remains a major cause of failure for the clinical treatment of this disease. Polo-like kinase 1 (Plk-1) is highly expressed in pancreatic cancer cell lines and pancreatic tumour tissues, and is involved in a wide variety of cell cycle processes. Nevertheless, its biological role and implication for gemcitabine resistance are not clearly defined. In this study, we used RNA-interference (RNAi)-mediated depletion of Plk-1 to determine its potential for sensitizing pancreatic tumour cells to gemcitabine. We showed that the level of Plk-1 protein was correlated significantly with gemcitabine resistance in human pancreatic adenocarcinoma cells and that overexpression of Plk-1 reduced sensitivity to gemcitabine in these cells. In addition, small interfering RNA (siRNA)-mediated knockdown of Plk-1 caused cell cycle arrest at G2/M and the reduction of cellular proliferation. More importantly, the treatment of pancreatic cancer cells with Plk-1 siRNA followed by exposure to gemcitabine dramatically decreased cell viability and increased cellular apoptosis, as compared with treatment with either agent alone. These observations indicate that down-regulation of Plk-1 expression by RNAi enhances gemcitabine sensitivity and increases gemcitabine cytotoxicity in pancreatic tumour cells. This is the first demonstration that the combination of Plk-1 gene therapy and gemcitabine chemotherapy has synergistic anti-tumour activity against pancreatic carcinoma in vitro. This combination treatment warrants further investigation as an effective therapeutic regimen for patients with resistant pancreatic cancer and other tumours.

Large-scale fabrication of ordered metallic hybrid nanostructures

A low-cost and high-throughput method for the fabrication of large-area ordered hybrid metallic nanostructure arrays is presented. Each structure unit is a nanobowl with a hexagonal distributed pillar array upon it. A self-assembled monolayer of polystyrene (PS) nanospheres is used as a template. After thermal evaporation, electroforming and removal of the nanospheres and the conductive layer, ordered arrays of hybrid nickel nanostructures have been fabricated. Both nanobowl arrays and pillar arrays exhibit uniform sizes. Smooth interior surfaces were observed in the nanobowl arrays. The geometry of the structure can be tuned by controlling the thickness of the conductive layer. The approach presented in this paper can be extended to fabricate ordered hybrid nanostructures of a wide range of metals and alloys with controlled size.

A large-area hybrid metallic nanostructure array and its optical properties

A process for fabricating a large-area hybrid metallic nanostructure array is presented. The structures consist of an array of metal capped dielectric nanopillars and an array of metallic holes, each possessing its individual optical properties. The plasmon response of such structures can be viewed as the collection of plasmons from two geometries to form an interacting system. Experimental results show two peak values in the extinction spectrum for p-polarized incident light. The two peaks in the extinction spectrum were shifted to longer wavelength and shorter wavelength respectively with the addition of absolute ethanol on the structure surface. The narrowest extinction peak appears at normal incidence.

[Molecular cloning and expression profile of a jasmonate biosynthetic pathway gene allene oxide cyclase from Hyoscyamus niger]

Hyoscyamus niger L. is a medicinal plant which produces a class of jasmonate-responsive pharmaceutical secondary metabolites named as tropane alkaloids. As a family of signaling phytohormones, jasmonates play significant roles in the biosynthesis of many plant secondary metabolites. In jasmonate biosynthetic pathway of plants, allene oxide cyclase (AOC, [...] EC 5.3.99.6 [...]) catalyzes the most important step. Here we cloned a cDNA from H. niger, named HnAOC (GenBank accession: AY708383), which was 1044 bp long, with a 747 bp open reading frame (ORF) encoding a polypeptide of 248 amino acid residues. Southern blot analysis indicated that it was a multi-copy gene. RT-PCR analysis revealed that the expression of HnAOC was regulated by various stresses and elicitors, with methyl-jasmonate showing the most prominent inducement. The characterization of HnAOC would be helpful for improving the production of valuable secondary metabolites by regulating the biosynthesis ofjasmonates.

The mitotic checkpoint kinase NEK2A regulates kinetochore microtubule attachment stability

Loss or gain of whole chromosome, the form of chromosome instability commonly associated with cancers is thought to arise from aberrant chromosome segregation during cell division. Chromosome segregation in mitosis is orchestrated by the interaction of kinetochores with spindle microtubules. Our studies show that NEK2A is a kinetochore-associated protein kinase essential for faithful chromosome segregation. However, it was unclear how NEK2A ensures accurate chromosome segregation in mitosis. Here we show that NEK2A-mediated Hec1 (highly expressed in cancer) phosphorylation is essential for faithful kinetochore microtubule attachments in mitosis. Using phospho-specific antibody, our studies show that NEK2A phosphorylates Hec1 at Ser165 during mitosis. Although such phosphorylation is not required for assembly of Hec1 to the kinetochore, expression of non-phosphorylatable mutant Hec1(S165) perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. Our in vitro reconstitution experiment demonstrated that Hec1 binds to microtubule in low affinity and phosphorylation by NEK2A, which prevents aberrant kinetochore-microtubule connections in vivo, increases the affinity of the Ndc80 complex for microtubules in vitro. Thus, our studies illustrate a novel regulatory mechanism in which NEK2A kinase operates a faithful chromosome attachment to spindle microtubule, which prevents chromosome instability during cell division.