Genetic diversity and ecogeographical differentiation among ribosomal DNA alleles in wild and cultivated barley

DNA from 267 accessions of wild barley from ecologically diverse habitats in Israel and Iran and from 92 accessions of cultivated barley from throughout the world were assayed for the 20 ribosomal DNA (rDNA) spacer-length variants that have been identified in the barley species. These 20 spacer-length variants, which are detectable by Southern blot hybridization, serve as markers of rDNA alleles of two Mendelian loci, Rrn1 and Rrn2. All of the populations of wild barley studied were polymorphic for both loci. In wild barley allele 112 (Rrn1) and allele 107 (Rrn2) behaved as widely adapted wild-type alleles; in our sample of cultivated barley allele 112 also behaved as a wild-type allele but allele 104 was somewhat more frequent than allele 107 in Rrn2. A few other alleles were locally frequent in wild barley. However, most of the 20 alleles were infrequent or rare and such alleles were often associated as "hitchhikers" with one of the wild-type alleles in compound two-component alleles. Allelic and genotypic frequencies differed widely in different habitats in correlation with eight of nine factors of the physical environment. Discrete log-linear multivariate analyses revealed statistically significant associations among alleles of Rrn1 and Rrn2. It was concluded that natural selection acting differentially on various rDNA alleles plays a major role in the development and maintenance of observed patterns of molecular and genetic organization of rDNA variability.

The co-expression of USP22 and BMI-1 may promote cancer progression and predict therapy failure in gastric carcinoma

Recent experimental evidence support the model in which the simultaneous induction of BMI-1 and USP22 is critical during cancer progression. Whether this model may affect gastric cancer (GC) progression is worthy of additional study. In this study, we examined the significance of the USP22 and BMI-1 expression in GC (n = 219), non-cancerous mucosa (n = 37), and lymph node metastasis (n = 37). The protein expression level of USP22 and BMI-1 were concomitantly up-regulated from non-cancerous mucosa to primary carcinoma and from carcinomas to lymph node metastasis (P < 0.001). A statistical correlation was observed between USP22 and BMI-1 expression in GC tissues (n = 219, r = 0.634, P < 0.001) and in lymph node metastasis (n = 37, r = 0.689, P < 0.001). The incidence of positive expression was 57.08% for USP22, 49.32% for BMI-1, and 45.21% for USP22/BMI-1 in 219 GC tissues, respectively. Co-positive of USP22/BMI-1 was significantly correlated with gross features (x(2) = 14.256, P < 0.001), differentiation (x(2) = 5.872, P = 0.015), pT classification (x(2) = 18.486, P < 0.001), pN classification (x(2) = 9.604, P = 0.002), pM classification (x(2) = 32.766, P < 0.001), and AJCC stage (x(2) = 58.278, P < 0.001). Notably, high USP22/BMI-1 expression was significantly associated with shorter disease-specific survival (P < 0.001). By Cox regression analysis, co-positive of USP22/BMI-1 was found to be an independent prognostic factor (P = 0.002). Our results indicated the simultaneous activation of USP22 and BMI-1 may associate with GC progression and therapy failure.

Risk assessment of nickel carcinogenicity and occupational lung cancer

Recent progress in risk assessment of nickel carcinogenicity and its correlation with occupational lung cancer in nickel-exposed workers is reviewed. Epidemiological investigations provide reliable data indicating the close relation between nickel exposure and high lung cancer risk, especially in nickel refineries. The nickel species-specific effects and the dose-response relationship between nickel exposure and lung cancer are among the main questions that are explored extensively. It is also suggested that some confounding factors such as cigarette smoking cannot be neglected. The determination of nickel concentration in lung tissue may be conducive to estimating the nickel exposure level, but it is uncertain whether the high nickel content in lung tissue indicates high lung cancer risk in nickel-exposed workers. Immunologic studies suggest that the suppressive effect of nickel on NK cell activity and interferon production may also be involved in the mechanisms of nickel carcinogenesis. As a potential mutagen, nickel can cause chromosome damage both in vitro and in vivo; and on a molecular basis, nickel is found to induce DNA damage (DNA strandbreaks and crosslinks, infidelity of DNA replication, inhibition of DNA repair, and the helical transition of B-DNA to Z-DNA) by binding of nickel ions to DNA and nuclear proteins. The discovery of oncogene promises both a challenge and an opportunity for nickel carcinogenesis research. It can be predicted that, with the rapid development of molecular biology and oncology, new approaches will be established for both understanding and controlling nickel-induced occupational lung cancer.

Reactive oxygen species and caspase activation mediate silica-induced apoptosis in alveolar macrophages

Alveolar macrophages (AMs) are the principal target cells of silica and occupy a key position in the pathogenesis of silica-related diseases. Silica has been found to induce apoptosis in AMs, whereas its underlying mechanisms involving the initiation and execution of apoptosis are largely unknown. The main objective of the present study was to examine the form of cell death caused by silica and the mechanisms involved. Silica-induced apoptosis in AMs was evaluated by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay and cell cycle/DNA content analysis. The elevated level of reactive oxygen species (ROS), caspase-9 and caspase-3 activation, and poly(ADP-ribose) polymerase (PARP) cleavage in silica-treated AMs were also determined. The results showed that there was a temporal pattern of apoptotic events in silica-treated AMs, starting with ROS formation and followed by caspase-9 and caspase-3 activation, PARP cleavage, and DNA fragmentation. Silica-induced apoptosis was significantly attenuated by a caspase-3 inhibitor, N-acetyl-Asp-Glu-Val-Asp aldehyde, and ebselen, a potent antioxidant. These findings suggest that apoptosis is an important form of cell death caused by silica exposure in which the elevated ROS level that results from silica exposure may act as an initiator, leading to caspase activation and PARP cleavage to execute the apoptotic process.

Ruthenium(II) ammine and hydrazine complexes with [N(Ph2PQ)2]- (Q = S, Se) ligands

Reactions of coordinatively unsaturated Ru[N(Ph2PQ)2]2(PPh3) (Q = S (1), Se (2)) with pyridine (py), SO2, and NH3 afford the corresponding 18e adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH3 (5); Q = Se, L = py (3), SO2 (4), NH3 (6)). The molecular structures of complexes 2 and 6 are determined. The geometry around Ru in 2 is pseudo square pyramidal with PPh3 occupying the apical position, while that in 6 is pseudooctahedral with PPh3 and NH3 mutually cis. The Ru-P distances in 2 and 6 are 2.2025(11) and 2.2778(11) A, respectively. The Ru-N bond length in 6 is 2.185(3) A. Treatment of 1 or 2 with substituted hydrazines L or NH2OH yields the respective adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH2NH2 (12), t-BuNHNH2 (14), l-aminopiperidine (C5H10NNH2) (15); Q = Se, L = PhCONHNH2 (7), PhNHNH2 (8), NH2OH (9), t-BuNHNH2 (10), C5H10NNH2 (11), NH2NH2 (13)), which are isolated as mixtures of their trans and cis isomers. The structures of cis-14 and cis-15 are characterized by X-ray crystallography. In both molecular structures, the ruthenium adopts a pseudooctahedral arrangement with PPh3 and hydrazine mutually cis. The Ru-N bond lengths in cis-14.CH2Cl2 and cis-15 are 2.152(3) and 2.101(3) A, respectively. The Ru-N-N bond angles in cis-14.CH2Cl2 and cis-15 are 120.5(4) and 129.0(2) degrees, respectively. Treatment of 1 with hydrazine monohydrate leads to the isolation of yellow 5 and red trans-Ru[N(Ph2PS)2]2(NH3)(H2O) (16), which are characterized by mass spectrometry, 1H NMR spectroscopy, and elemental analyses. The geometry around ruthenium in 16 is pseudooctahedral with the NH3 and H2O ligands mutually trans. The Ru-O and Ru-N bond distances are 2.118(4) and 2.142(6) A, respectively. Oxidation reactions of the above ruthenium hydrazine complexes are also studied.

Antigenic difference between viral strains causing classical and mild types of epidemic hemorrhagic fever with renal syndrome in China

The antigenic relationship between viral isolates from Apodemus and Rattus that appear to cause the classical and mild types of epidemic hemorrhagic fever (EHF) in China was studied by cross-immunofluorescence, cross-neutralization, immunofluorescence blocking tests, and cross-enzyme-linked immunosorbent assay (ELISA). Obvious antigenic diversity between the isolates was demonstrated by cross-neutralization, immunofluorescence blocking tests, and cross-ELISA. Antisera from patients with classical EHF neutralized viruses of both types to a similar degree, but antisera from patients with mild EHF showed little neutralization of apodemus virus. Similarly, antisera from classical EHF blocked immunofluorescence by monoclonal antibody (25-1 McAb) derived from apodemus virus to both viral antigens, but antisera from mild EHF gave only low-grade blocking against apodemus viral antigen. Direct antigenic titrations of both viral strains by cross-ELISA yielded similar results. That distinct antigenic differences exist between viral strains causing these two types of EHF might be of great importance to the serological differentiation of the viruses and the study of EHF vaccine.

Heterometallic polymeric clusters containing tetraselenotungstate anion: one-dimensional helical chain [[La(Me2SO)8

[PPh4]2[WSe4] reacts with an equivalent of [Ag(MeCN)4][ClO4] in DMF to afford a linear polymeric cluster [[Ph4P][(mu-WSe4)Ag]]n (1). Treatment of cluster 1 with excess La(NO3)3.3H2O in Me2SO solution resulted in the formation of a helical chain polymeric cluster [[La(Me2SO)8][(mu-WSe4)3Ag3]]n (2). Cluster 2 crystallizes in the monoclinic space group P2(1/n) with four formula units in a cell of dimensions a = 12.7642(5) A, b = 24.1725(9) A, c = 19.4012(7) A, and beta = 103.546(11) degrees. Refinement by full-matrix least-squares techniques gave final residuals R = 0.0540 and Rw = 0.1116 for 494 variables and 7593 reflections (Fo(2) > 2.0sigma(Fo(2))). The anion [[(mu-WSe4)3Ag3]]n(3n-) in 2 can be described as a butterfly-type SeWSe3Ag2 basic repeating unit linked through interactions with a Ag atom of one fragment and a Ag atom of another to form an intriguing helical array. The CuCN, KCN, and [Et4N]2[WSe4] reaction system resulted in the formation of a novel three-dimensional cluster [[Et4N]2[(mu4-WSe4)Cu4(CN)4]]n (4) either in DMF/2-picoline or in solid at 80 degrees C. Cluster 4 crystallizes in the orthorhombic space group Fddd with cell constants a = 11.090(2) A, b = 23.206(5) A, c = 23.910(5) A, and Z = 8. Anisotropic refinement with 1510 reflections (Fo(2) > 2.0sigma(Fo(2))) and 82 parameters for all non-hydrogen atoms yielded the values of R = 0.0428 and Rw = 0.0887. The anion structure of 4 is built up from a WSe4Cu4 unit bridged by cyanide ligands to form a three-dimensional cross framework. The air- and moisture-stable polymeric clusters easily decompose into small molecular clusters when treated with ligands such as PPh3 and pyridine (Py). Cluster 2 exhibits both strong optical absorption and an optical self-focusing effect (effective alpha2 = 2.2 x 10(-9) m2.W(-1), n2 = 6.8 x 10(-15) m2.W(-1); examined in a 0.13 mM DMF solution). Cluster 4 shows good photostability in the process of measurement and a large optical limiting effect (the limiting threshold is ca. 0.2 J.cm(-2)).

Effects on adaptedness of variations in ribosomal DNA copy number in populations of wild barley (Hordeum vulgare ssp. spontaneum)

Twenty alleles, 12 at Mendelian locus Rrn1 and 8 at locus Rrn2, control rRNA genes [ribosomal DNA (rDNA)] variability in barley. These alleles differ strikingly in their effects on adaptedness. In the present study, we determined variation in the copy number of 101 accessions of wild barley plants from 10 ecologically diverse sites in Israel and examined relationships between rDNA copy number and adaptedness. The average multiplicity of rDNA per haploid genome was 1881 copies and the average numbers of copies for Rrn1 and Rrn2 were 962 and 917, respectively. The total number of copies as well as the number of copies for Rrn1 and Rrn2 varied widely from plant to plant within sites and also from site to site. The predominant allele of Rrn2 had somewhat more copies on the average than the other alleles of this locus but differences between the predominant allele and other alleles of Rrn1 were not statistically significant. Overall, the results indicated that differing amounts of rDNA resulting from variations in copy number and/or number of subrepeats in the intergenic spacer region were not closely associated with adaptedness. This suggests that the high adaptedness of a few specific alleles results in large part from adaptatively favorable nucleotide sequences in the transcription units and/or the intergenic spacer regions of the favored alleles--i.e., that adaptedness in barley depends on the quality more than on the quantity of rDNA present.

Involvement of oxidative stress in crystalline silica-induced cytotoxicity and genotoxicity in rat alveolar macrophages

Alveolar macrophages (AMs) occupy a key position in silica-induced pulmonary fibrosis, although the mechanisms are yet to be elucidated. In the present study we examined the involvement of oxidative stress and reactive oxygen species formation in silica-induced cytotoxicity and genotoxicity in cultured rat AMs. A lucigenin-dependent chemiluminescence test was used to determine superoxide anion (O(-)(2)), and a 2',7'-dichlorofluorescin diacetate fluorescence test was employed to measure the hydrogen peroxide (H(2)O(2)) level. The cytotoxic and genotoxic effects caused by silica in AMs were examined by lactate dehydrogenase (LDH) leakage and single-cell gel electrophoresis (comet assay), respectively. The results showed that silica enhanced O(-)(2) and H(2)O(2) formation in AMs. There were clear dose- and time-dependent relationships in silica-induced cytotoxicity and genotoxicity. Furthermore, superoxide dismutase and catalase were able to reduce silica-induced LDH leakage and DNA damage, with concurrent significant inhibition on silica-induced oxidative stress in AMs. These findings provide convincing evidence that oxidative stress mediates the silica-induced cytotoxicity and genotoxicity. The understanding of such a mechanism may provide a scientific basis for the possible application of antioxidants in preventing the hazardous effects of silica.

Expression of cyclooxygenase-2 and clinicopathologic features in human gastric adenocarcinoma

AIM: To study the expression of cyclooxygenase-2 (COX-2) gene in gastric cancer and the relationship between COX-2 expression and clinicopathologic features of gastric cancer.

METHODS: With reference to the expression of β-actin gene, COX-2 mRNA level was examined in cancerous tissues and adjacent noncancerous mucosa from 33 patients by semiquantitative reverse transcription- polymerase chain reaction (RT-PCR). Quantitation of relative band Adj volume counts was performed using molecular Analyst for windows software. The COX-2 index was determined from the band Adj volume counts ratio of COX-2 to constitutively expressed actin.

RESULTS: The COX-2 index in gastric carcinoma was significantly higher than that in normal mucosa (0.5966 ± 0.2659 vs 0.2979 ± 0.171, u = 5.4309, P < 0.01). Significantly higher expression of COX-2 mRNA was also observed in patients with lymph node involvement than that in those without (0.6775 ± 0.2486 vs 0.4105 ± 0.2182, t = 2.9341, P < 0.01). Furthermore, the staging in the UICC TNM classification significantly correlated with COX-2 overexpression (F = 3.656, P < 0.05), the COX-2 index in stage III and IV was significantly higher than those in stage I and II (q = 3.2728 and q = 3.4906, P < 0.05). The COX-2 index showed no correlation with patient抯 age, sex, blood group, tumor location, gross typing, depth of invasion, differentiation, and the greatest tumor dimension (P > 0.05).

CONCLUSION: Expression of COX-2 mRNA in gastric carcinoma was significantly higher, which may enhance lymphatic metastasis in patients with gastric carcinoma. The staging in the UICC TNM classification was significantly correlated with COX-2 over-expression. COX-2 may contribute to progression of tumor in human gastric adenocarcinoma.

CARMA3 regulates the invasion, migration, and apoptosis of non-small cell lung cancer cells by activating NF-кB and suppressing the P38 MAPK signaling pathway

In our previous study, CARMA3 overexpression in lung cancer cells promoted cell proliferation and invasion; however, the mechanism underlying the role of CARMA3 in cancer cell invasion remained unclear. In the present study, knockdown of CARMA3 in A549 and H1299 cells suppressed cell invasion and migration, and downregulated matrix metalloprotease 9 expression at the protein and mRNA levels, as shown by Western blotting and real-time PCR. CARMA3 knockdown increased cell apoptosis, as shown by flow cytometry, increased the mRNA and protein expression levels of Bax and Caspase3, and downregulated Bcl-2 in A549 and H1299 cells. Phosphorylated P38 levels increased and NF-кB activation decreased following knockdown of CARMA3. SB203580, a P38 MAPK inhibitor, activated NF-кB, increased cell migration, and inhibited cell apoptosis after knockdown of CARMA3 compared to knockdown of CARMA3 without SB203580. These findings indicate that CARMA3 may suppress the activation of the P38 MAPK signaling pathway to regulate invasion, migration and apoptosis of lung cancer cells by activating NF-кB (P65) in the nucleus.

MicroRNA-200b inhibits epithelial-mesenchymal transition and migration of cervical cancer cells by directly targeting RhoE

Previous studies have identified microRNA-200b (miR-200b) as a powerful regulator of epithelial-mesenchymal transition (EMT) via the control of gene expression. EMT is a critical event that is associated with the initiation of malignant tumor metastasis. A lack of E-cadherin expression and overexpression of vimentin are hallmarks of EMT. It is well‑known that RhoE, which is associated with regulation of the actin cytoskeleton and migration via alterations in cell motility, regulates the expression of E-cadherin, matrix metalloproteinase-9 (MMP-9) and vimentin. However, it remains to be elucidated whether miR‑200b may alter the molecular behavior of RhoE. The present study aimed to determine whether miR‑200b was able to regulate the EMT of cervical cancer, in order to control metastasis. In addition, the correlation between miR‑200b and RhoE, E‑cadherin and vimentin expression was investigated. Notably, miR‑200b was shown to inhibit the function of RhoE and suppress the EMT of cervical cancer. Furthermore, HeLa cells were transfected with miR‑200b mimics or inhibitors, and the protein expression levels of E‑cadherin, MMP‑9, vimentin and RhoE were subsequently detected. A Transwell assay was also conducted, in order to observe the metastatic ability of the HeLa cells. In addition, a luciferase reporter assay was performed using luciferase reporter vectors containing the full length 3'‑untranslated region (UTR) of RhoE; miR‑200b was able to significantly suppress relative luciferase activity by targeting the 3'‑UTR of RhoE. These results suggested that miR‑200b may markedly inhibit metastatic potential by regulating cell EMT and inhibiting RhoE; therefore, miR-200b may be considered an effective target for the treatment of patients with highly metastatic cervical cancer.

MicroRNA-200b suppresses cell invasion and metastasis by inhibiting the epithelial-mesenchymal transition in cervical carcinoma

The expression of microRNA (miR)-200b is suppressed in numerous tumor types, leading to epithelial-mesenchymal transition, which enables solid tissue epithelial cancers to invade and metastasize. The present study assessed the role of miR-200b in cervical cancer with the aim of clarifying the underlying pathophysiological mechanisms and to identify potential strategies for its prevention and treatment of cervical cancer. Reverse‑transcription quantitative PCR revealed that miR‑200b was downregulated in invasive cervical carcinoma tissues compared with that in normal adjacent tissues. A Transwell migration assay indicated that transfection of cervical cancer cells with miR‑200b mimics significantly inhibited their migratory potential, while migration was enhanced in cells transfected with miR‑200b inhibitor. Furthermore, western blot analysis indicated a negative correlation between miR‑200b and mesenchymal marker vimentin as well as matrix metalloproteinase‑9, which has a key role in tumor invasion and metastasis. In addition, a positive correlation between miR‑200b and the epithelial marker E‑cadherin was revealed by western blot and immunofluorescence. The results of the present study suggested that miR‑200b suppressed the migratory potential of cervical carcinoma cells and therefore their ability to metastasize by inhibiting the epithelial-mesenchymal transition, which may be utilized for the treatment of cervical cancer.

Critical role of GSH in silica-induced oxidative stress, cytotoxicity, and genotoxicity in alveolar macrophages

The main objective of this study was to evaluate the critical role of glutathione (GSH) in silica-induced oxidative stress, cytotoxicity, and genotoxicity in rat alveolar macrophages (AMs). Silica-induced superoxide radical and hydrogen peroxide formation were determined with lucigenin-dependent chemiluminescence and 2', 7'-dichlorofluorescin diacetate fluorescence test, respectively. The cytotoxicity of silica was estimated by lactate dehydrogenase leakage, and a comet assay was used for examining silica-induced DNA damage in AMs. The intracellular GSH content was modulated by N-acetylcysteine, a GSH precursor, and buthionine sulfoximine, a specific GSH synthesis inhibitor. It was found that silica led to a dose- and time-dependent decrease in GSH content in AMs. N-acetylcysteine increased intracellular GSH level and protected against silica-induced reactive oxygen species formation, lactate dehydrogenase leakage, and DNA strand breaks in AMs. In contrast, buthionine sulfoximine pretreatment depleted cellular GSH and enhanced the susceptibility of AMs to the cytotoxic and genotoxic effects of silica. It thus appears that GSH plays a critical role in protecting against silica-induced cell injury, most probably through its antioxidant activity.

Role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism

Our aim was to investigate the role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism. Coronary angiography and intravascular ultrasound (IVUS) were performed in 60 stable angina pectoris (SAP) patients and 60 unstable angina pectoris (UAP) patients. The chemotactic activity of monocytes in the 2 groups of patients was examined in Transwell chambers. High-sensitivity C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), regulated on activation in normal T-cell expressed and secreted (RANTES), and fractalkine in serum were examined with ELISA kits, and expression of MCP-1, RANTES, and fractalkine mRNA was examined with real-time PCR. In the SAP group, 92 plaques were detected with IVUS. In the UAP group, 96 plaques were detected with IVUS. The plaques in the UAP group were mainly lipid 51.04% (49/96) and the plaques in the SAP group were mainly fibrous 52.17% (48/92). Compared with the SAP group, the plaque burden and vascular remodeling index in the UAP group were significantly greater than in the SAP group (P<0.01). Chemotactic activity and the number of mobile monocytes in the UAP group were significantly greater than in the SAP group (P<0.01). Concentrations of hs-CRP, MCP-1, RANTES, and fractalkine in the serum of the UAP group were significantly higher than in the serum of the SAP group (P<0.05 or P<0.01), and expression of MCP-1, RANTES, and fractalkine mRNA was significantly higher than in the SAP group (P<0.05). MCP-1, RANTES, and fractalkine probably promote instability of coronary atherosclerotic plaque.

Expression and correlation of CD44v6, vascular endothelial growth factor, matrix metalloproteinase-2, and matrix metalloproteinase-9 in Krukenberg tumor

AIM: To explore the expression and correlation of CD44v6, vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2 and matrix metalloproteinase (MMP)-9 in Krukenberg and primary epithelial ovarian carcinoma.

METHODS: The expressions of CD44v6, VEGF, MMP-2 and MMP-9 were detected by immunohistochemical method in 20 cases of normal ovarian tissues, 38 cases of Krukenberg tumor and 45 cases of primary epithelial ovarian carcinoma.

RESULTS: The expression of CD44v6 (primary epithelial ovarian carcinoma tissue vs normal ovarian tissue: χ² = 4.516, P = 0.034; Krukenberg tumor tissue vs normal ovarian tissue: χ² = 19.537, P = 0.001) and VEGF (primary epithelial ovarian carcinoma tissue vs normal ovarian tissue: P = 0.026; Krukenberg tumor tissue vs normal ovarian tissue: χ² = 22.895, P = 0.001) was significantly higher in primary epithelial ovarian carcinoma tissue and Krukenberg tumor tissue than in normal ovarian tissue. The positive expression rate of MMP-2 and MMP-9 was 0% in the normal ovarian tissue. The positive expression rate of CD44v6 (χ² = 10.398, P = 0.001), VEGF (χ² = 13.149, P = 0.001), MMP-2 (χ² = 33.668, P = 0.001) and MMP-9 (χ² = 38.839, P = 0.001) was remarkably higher in Krukenberg tumor than in primary epithelial ovarian carcinoma. The correlation of CD44v6, VEGF, MMP-2, and MMP-9 was observed in primary epithelial ovarian carcinoma and Krukenberg tumor.

CONCLUSION: CD44v6, VEGF, MMP-2, and MMP-9 are involved in ovarian carcinoma, gastric cancer and Krukenberg tumor. Detection of CD44v6, VEGF, MMP-2 and MMP-9 may contribute to the diagnosis of ovarian carcinoma, gastric cancer, and Krukenberg tumor.

The effects of contacts and ambipolar electrical transport in nitrogen doped multiwall carbon nanotubes

The electrical transport properties of pristine single wall carbon nanotubes (SWCNTs) and lower nitrogen content doped multiwall carbon nanotubes (MWCNTs) (lower than in the experiments of Xiao et al (2005 J. Am. Chem. Soc. 127 8614)) in contact with Au and Pt were studied. Compared with pristine SWCNTs, the Fermi level of the lower nitrogen content doped MWCNTs also moved to the valence band edge with the contact metal's work function increasing. In contrast to Derycke et al' s results (2002 Appl. Phys. Lett. 80 2773), the lower nitrogen content doped MWCNTs exhibited ambipolar behavior, and increasing the doping level led to a reduction of the Schottky barrier height of electrons. Consistent with theoretical calculations, the results support the opinion that the degree of Fermi level pinning is minor for doped carbon nanotubes.

Size-dependent electrical transport properties in Co nanocluster-assembled granular films

A series of Co nanocluster-assembled films with cluster sizes ranging from 4.5 nm to 14.7 nm were prepared by the plasma-gas-condensation method. The size-dependent electrical transport properties were systematically investigated. Both of the longitudinal resistivity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{xx}$$\end{document}ρxx) and saturated anomalous Hall resistivity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{xy}^{A}$$\end{document}ρxyA) continuously increased with the decrease of the cluster sizes (d). The \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{xx}$$\end{document}ρxx firstly increased and then decreased with increasing the temperature for all samples, which could be well described by involving the thermally fluctuation-induced tunneling (FIT) process and scattering. The tunneling effect was verified to result in the invalidation of classical anomalous Hall effect (AHE) scaling relation. After deducting the contribution from tunneling effect to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{xx}$$\end{document}ρxx, the AHE scaling relation between \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{xy}^{A}$$\end{document}ρxyA and the scattering resistivity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{S}$$\end{document}ρS) by varying the temperature was reconstructed. The value of scaling exponent γ increased with increasing Co cluster sizes. The size dependence of γ might be qualitatively interpreted by the interface and surface-induced spin flip scattering. We also determined the scaling relation between \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{xy}^{A}$$\end{document}ρxyA and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rho }_{S}$$\end{document}ρS at 5 K by changing the Co cluster sizes, and a large value of γ = 3.6 was obtained which might be ascribed to the surface and interfacial scattering.

Temporal variations of mobile carbohydrates in Abies fargesii at the upper tree limits

Low temperatures are associated high-altitude treelines, but the functional mechanism of treeline formation remains controversial. The relative contributions of carbon limitation (source activity) and growth limitation (sink activity) require more tests across taxa and regions. We examined temporal variations of mobile carbon supply in different tissues of Abies fargesii across treeline ecotones on north- and south-facing slopes of the Qinling Mountains, China. Non-structural carbohydrate (NSC) concentrations in tissues along the altitudinal gradient on both slopes changed significantly in the early and late growing season, but not in the mid-growing season, indicating the season-dependent carbon supply status. Late in the growing season on both slopes, trees at the upper limits had the highest NSC concentrations and total soluble sugars and lowest starch concentrations compared to trees at the lower elevations. NSC concentrations tended to increase in needles and branches throughout the growing season with increasing elevation on both slopes, but declined in roots and stems. NSC concentrations across sampling dates also indicated increases in needles and branches, and decreases in roots and stem with increasing elevation. Overall altitudinal trends of NSC in A. fargesii revealed no depletion of mobile carbon reserves at upper elevation limits, suggesting limitation of sink activity dominates tree life across treeline ecotones in both north- and south-facing slopes. Carbon reserves in storage tissues (especially roots) in the late growing season might also play an important role in winter survival and early growth in spring at upper elevations on both slopes, which define the uppermost limit of A. fargesii.

Nanodiode based on a multiwall CN(x)/carbon nanotube intramolecular junction

We prepared multiwall carbon nanotubes (MWCNTs) from the pyrolysis of ferrocene, and CN(x) nanotubes from a mixture of ferrocene and melamine. Under well chosen synthesis conditions, massive multiwall CN(x)/carbon nanotube intramolecular junctions were successfully fabricated. The individual nanotubes were used as conductance channels to obtain their transport characteristic information. Measurement results showed that the current-voltage (I-V) curve of the CN(x)/CNT junction is highly asymmetric, behaving like a diode. Moreover, the devices are very stable in ambient environment. We attribute this nonlinear property of the CN(x)/CNT junctions to their two different atomic and electronic sections.

Population structure and genetic diversity of Setosphaeria turcica from corn in Heilongjiang province, China

AIM

The aims of this study were to identify races and mating types of Setosphaeria turcica causing northern corn leaf blight in Heilongjiang province of China and analyse the genetic diversity of S. turcica isolates using SSR markers.

METHODS AND RESULTS

Based on gene-for-gene interactions, 13 races of S. turcica (races 0, 1, 2, 3, 12, 13, 23, 123, N, 1N, 12N, 3N and 23N) were isolated from infected corn plants in Heilongjiang province. Races 0 and 1 were the predominant races, and race 23N was identified for the first time in the region. Using two pairs of specific primers, three mating types, 'a', 'Aa' and 'A', were identified, with 'a' being the predominant mating type. SSR markers were used to analyse genetic diversity of 60 S. turcica isolates. Five SSR primers were polymorphic, which resulted in 45 reproducible bands with 2-15 bands for each primer. Cluster analysis separated the isolates into five groups at a similarity coefficient of 0·84. Analysis of molecular variance showed that there was significant correlation between SSR groups and mating type of the isolates. No significant correlation was found between SSR groups and physiological races or geographical location of the isolates.

CONCLUSIONS

The work reported that races 0 and 1 were the predominant races, and race 23N was identified for the first time in Heilongjiang province with 'a' being the predominant mating type. There was significant correlation between SSR groups and mating type of S. turcica isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide information on population structure and genetic diversity of S. turcica causing Northern corn leaf blight, which will facilitate the development of effective disease management programs.

[Expression of long noncoding RNA STCAT3 in gastric cancer tissues and its effect on malignant phenotype of gastric cancer cells]

Objective: To detect the expression of long noncoding RNA(lncRNA)stomach cancer-associated transcript-3(STCAT3) in gastric cancer tissues, adjacent tissues, human gastric cancer cell lines and normal gastric epithelial cell lines, and to investigate the relationship between STCAT3 expression and clinicopathological features and malignant phenotype of gastric cancer. Methods: Quantitative fluorescent real-time polymerase chain reaction (qRT-PCR) was applied to detect the lncRNA STCAT3 expression levels in gastric cancer tissues, paired adjacent non-tumorous tissues, in order to explore the relationship between STCAT3 expression and clinicopathological features of gastric cancer. lncRNA STCAT3 low-expressing and high-expressing gastric cancer cell lines were transfected with expression plasmid to simulate gain-of-function, or interference plasmid to achieve loss-of-function. Cell proliferation was measured with CCK-8 and colony formation assay, cell migration with scratch assay, and cell invasion with Transwell migration assay. human gastric tumor were also transplanted to nude mice to detect the effect of lncRNA STCAT3 on tumorigenesis. Results: The expression of lncRNA STCAT3 was generally up-regulated in gastric cancer tissues compared with the adjacent tissues(12.55±0.16 vs 6.52±0.14), with median expression level in gastric cancer tissues being 6.03 higher (P<0.05). Meanwhile, the expression level of lncRNA STCAT3 in gastric cancer tissues was not correlated with age or gender (both P>0.05), while positively correlated with TNM stage (P<0.05). Interference of lncRNA STCAT3 expression in BGC-823 cells was found associated with significantly suppressed colony formation, proliferation, invasion, and migration (all P<0.05). Over-expression of lncRNA STCAT3 in AGS cells were also founded could promote the gastric cancer cells' proliferation, colony formation, migration, and invasion (all P<0.05). Conclusions: lncRNA STCAT3 may participate in the proliferation and invasion of gastric cancer cells, indicating that dysregulation of STCAT3 expression may play a role in occurrence and development of gastric cancer. lncRNA STCAT3 has the potential to be the biomarker of gastric cancer progression and target in treatment. The underlying mechanism is yet to be further studied.