115 research outputs found

    Genetic polymorphisms in glutathione S-transferase (GST) superfamily and risk of arsenic-induced urothelial carcinoma in residents of southwestern Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Arsenic exposure is an important public health issue worldwide. Dose-response relationship between arsenic exposure and risk of urothelial carcinoma (UC) is consistently observed. Inorganic arsenic is methylated to form the metabolites monomethylarsonic acid and dimethylarsinic acid while ingested. Variations in capacity of xenobiotic detoxification and arsenic methylation might explain individual variation in susceptibility to arsenic-induced cancers.</p> <p>Methods</p> <p>To estimate individual susceptibility to arsenic-induced UC, 764 DNA specimens from our long-term follow-up cohort in Southwestern Taiwan were used and the genetic polymorphisms in GSTM1, GSTT1, GSTP1 and arsenic methylation enzymes including GSTO1 and GSTO2 were genotyped.</p> <p>Results</p> <p>The GSTT1 null was marginally associated with increased urothelial carcinoma (UC) risk (HR, 1.91, 95% CI, 1.00-3.65), while the association was not observed for other GSTs. Among the subjects with cumulative arsenic exposure (CAE) ≥ 20 mg/L*year, the GSTT1 null genotype conferred a significantly increased cancer risk (RR, 3.25, 95% CI, 1.20-8.80). The gene-environment interaction between the GSTT1 and high arsenic exposure with respect to cancer risk was statistically significant (multiplicative model, <it>p </it>= 0.0151) and etiologic fraction was as high as 0.86 (95% CI, 0.51-1.22). The genetic effects of GSTO1/GSTO2 were largely confined to high arsenic level (CAE ≥ 20). Diplotype analysis showed that among subjects exposed to high levels of arsenic, the AGG/AGG variant of GSTO1 Ala140Asp, GSTO2 5'UTR (-183)A/G, and GSTO2 Asn142Asp was associated with an increased cancer risk (HRs, 4.91, 95% CI, 1.02-23.74) when compared to the all-wildtype reference, respectively.</p> <p>Conclusions</p> <p>The GSTs do not play a critical role in arsenic-induced urothelial carcinogenesis. The genetic effects of GSTT1 and GSTO1 on arsenic-induced urothelial carcinogenesis are largely confined to very high exposure level.</p

    A Sliced Inverse Regression (SIR) Decoding the Forelimb Movement from Neuronal Spikes in the Rat Motor Cortex

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    Several neural decoding algorithms have successfully converted brain signals into commands to control a computer cursor and prosthetic devices. A majority of decoding methods, such as population vector algorithms (PVA), optimal linear estimators (OLE), and neural networks (NN), are effective in predicting movement kinematics, including movement direction, speed and trajectory but usually require a large number of neurons to achieve desirable performance. This study proposed a novel decoding algorithm even with signals obtained from a smaller numbers of neurons. We adopted sliced inverse regression (SIR) to predict forelimb movement from single-unit activities recorded in the rat primary motor (M1) cortex in a water-reward lever-pressing task. SIR performed weighted principal component analysis (PCA) to achieve effective dimension reduction for nonlinear regression. To demonstrate the decoding performance, SIR was compared to PVA, OLE, and NN. Furthermore, PCA and sequential feature selection (SFS) which are popular feature selection techniques were implemented for comparison of feature selection effectiveness. Among SIR, PVA, OLE, PCA, SFS, and NN decoding methods, the trajectories predicted by SIR (with a root mean square error, RMSE, of 8.47 ± 1.32 mm) was closer to the actual trajectories compared with those predicted by PVA (30.41 ± 11.73 mm), OLE (20.17 ± 6.43 mm), PCA (19.13 ± 0.75 mm), SFS (22.75 ± 2.01 mm), and NN (16.75 ± 2.02 mm). The superiority of SIR was most obvious when the sample size of neurons was small. We concluded that SIR sorted the input data to obtain the effective transform matrices for movement prediction, making it a robust decoding method for conditions with sparse neuronal information

    Examining the Dimensionality, Reliability, and Invariance of the Depression, Anxiety, and Stress Scale–21 (DASS-21) Across Eight Countries

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    © The Author(s) 2020. This study evaluated the dimensionality, invariance, and reliability of the Depression, Anxiety, and Stress Scale–21 (DASS-21) within and across Brazil, Canada, Hong Kong, Romania, Taiwan, Turkey, United Arab Emirates, and the United States (N = 2,580) in college student samples. We used confirmatory factor analyses to compare the fit of four different factor structures of the DASS-21: a unidimensional model, a three-correlated-factors model, a higher order model, and a bifactor model. The bifactor model, with three specific factors (depression, anxiety, and stress) and one general factor (general distress), presented the best fit within each country. We also calculated ancillary bifactor indices of model-based dimensionality of the DASS-21 and model-based reliability to further examine the validity of the composite total and subscale scores and the use of unidimensional modeling. Results suggested the DASS-21 can be used as a unidimensional scale. Finally, measurement invariance of the best fitting model was tested across countries indicating configural invariance. The traditional three-correlated-factors model presented scalar invariance across Canada, Hong Kong, Romania, Taiwan, and the United States. Overall, these analyses indicate that the DASS-21 would best be used as a general score of distress rather than three separate factors of depression, anxiety, and stress, in the countries studied

    Cross-Cultural Validation of the Perceptions of Stigmatization by Others for Seeking Help (PSOSH) Scale

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    Social network stigma refers to the perceived negative views about seeking help for mental health problems that are held by those closest to an individual, such as family and friends. This form of stigma predicts help-seeking attitudes and intentions beyond other forms of stigma, and is predominantly measured using the Perceptions of Stigmatization by Others for Seeking Help scale (PSOSH; Vogel, Wade, & Ascheman, 2009). However, the PSOSH was normed using samples from the United States and, until the cross-cultural validity of this measure is established, it cannot reliably be used within other countries (Miller & Sheu, 2008). As such, the current study (N = 3,440) examined the cross-cultural measurement invariance of the PSOSH using the sequential constraint imposition approach across 11 countries/regions: Australia, Brazil, Canada, Hong Kong, Portugal, Romania, Taiwan, Turkey, the United Arab Emirates (UAE), the United Kingdom (U.K.), and the United States (U.S.). Overall, findings indicate that the PSOSH measures a meaningful construct (i.e., configural and metric invariance) across the 11 countries/regions and that future cross-cultural research could use the PSOSH to examine relationships between social network stigma and other variables. Scalar invariance results also supported the examination of mean differences in Australia, Brazil, Canada, Portugal, Turkey, the U.K., and the U.S., but not in Hong Kong, Romania, Taiwan, and UAE. Implications for future cross-cultural research are discussed

    Stigma of Seeking Psychological Services: Examining College Students Across Ten Countries/Regions

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    © Division of Counseling Psychology of the American Psychological Association. Stigma is an important barrier to seeking psychological services worldwide. Two types of stigma exist: public stigma and self-stigma. Scholars have argued that public stigma leads to self-stigma, and then self-stigma is the primary predictor of attitudes toward seeking psychological services. However, this assertion is largely limited to U.S. samples. The goal of this research was to provide a first step in understanding the relationship between public stigma, self-stigma, and attitudes toward seeking psychological services in international contexts (N = 3,276; Australia, Brazil, Canada, Hong Kong, Portugal, Romania, Taiwan, Turkey, United Arab Emirates, and United States). Using structural equation modeling, we found that self-stigma mediated the relationship between public stigma and attitudes toward seeking services among college students in each country and region. However, differences in path strengths emphasize the need to pay attention to the role of public and self-stigma on attitudes toward seeking psychological services throughout the world

    Cross-Cultural Validation of the Perceptions of Stigmatization by Others for Seeking Help (PSOSH) Scale.

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    Social network stigma refers to the perceived negative views about seeking help for mental health problems that are held by those closest to an individual, such as family and friends. This form of stigma predicts help-seeking attitudes and intentions beyond other forms of stigma, and is predominantly measured using the Perceptions of Stigmatization by Others for Seeking Help scale (PSOSH; Vogel, Wade, & Ascheman, 2009). However, the PSOSH was normed using samples from the United States and, until the cross-cultural validity of this measure is established, it cannot reliably be used within other countries (Miller & Sheu, 2008). As such, the current study (N = 3,440) examined the cross-cultural measurement invariance of the PSOSH using the sequential constraint imposition approach across 11 countries/regions: Australia, Brazil, Canada, Hong Kong, Portugal, Romania, Taiwan, Turkey, the United Arab Emirates (UAE), the United Kingdom (U.K.), and the United States (U.S.). Overall, findings indicate that the PSOSH measures a meaningful construct (i.e., configural and metric invariance) across the 11 countries/regions and that future cross-cultural research could use the PSOSH to examine relationships between social network stigma and other variables. Scalar invariance results also supported the examination of mean differences in Australia, Brazil, Canada, Portugal, Turkey, the U.K., and the U.S., but not in Hong Kong, Romania, Taiwan, and UAE. Implications for future cross-cultural research are discussed

    The Affinity of Elongated Membrane-Tethered Ligands Determines Potency of T Cell Receptor Triggering

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    T lymphocytes are important mediators of adoptive immunity but the mechanism of T cell receptor (TCR) triggering remains uncertain. The interspatial distance between engaged T cells and antigen-presenting cells (APCs) is believed to be important for topological rearrangement of membrane tyrosine phosphatases and initiation of TCR signaling. We investigated the relationship between ligand topology and affinity by generating a series of artificial APCs that express membrane-tethered anti-CD3 scFv with different affinities (OKT3, BC3, and 2C11) in addition to recombinant class I and II pMHC molecules. The dimensions of membrane-tethered anti-CD3 and pMHC molecules were progressively increased by insertion of different extracellular domains. In agreement with previous studies, elongation of pMHC molecules or low-affinity anti-CD3 scFv caused progressive loss of T cell activation. However, elongation of high-affinity ligands (BC3 and OKT3 scFv) did not abolish TCR phosphorylation and T cell activation. Mutation of key amino acids in OKT3 to reduce binding affinity to CD3 resulted in restoration of topological dependence on T cell activation. Our results show that high-affinity TCR ligands can effectively induce TCR triggering even at large interspatial distances between T cells and APCs

    Glyoxalase-I Is a Novel Prognosis Factor Associated with Gastric Cancer Progression

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    Glyoxalase I (GLO1), a methylglyoxal detoxification enzyme, is implicated in the progression of human malignancies. The role of GLO1 in gastric cancer development or progression is currently unclear. The expression of GLO1 was determined in primary gastric cancer specimens using quantitative polymerase chain reaction, immunohistochemistry (IHC), and western blotting analyses. GLO1 expression was higher in gastric cancer tissues, compared with that in adjacent noncancerous tissues. Elevated expression of GLO1 was significantly associated with gastric wall invasion, lymph node metastasis, and pathological stage, suggesting a novel role of GLO1 in gastric cancer development and progression. The 5-year survival rate of the lower GLO1 expression groups was significantly greater than that of the higher expression groups (log rank P = 0.0373) in IHC experiments. Over-expression of GLO1 in gastric cancer cell lines increases cell proliferation, migration and invasiveness. Conversely, down-regulation of GLO1 with shRNA led to a marked reduction in the migration and invasion abilities. Our data strongly suggest that high expression of GLO1 in gastric cancer enhances the metastasis ability of tumor cells in vitro and in vivo, and support its efficacy as a potential marker for the detection and prognosis of gastric cancer

    Angiogenesis in Differentiated Placental Multipotent Mesenchymal Stromal Cells Is Dependent on Integrin α5β1

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    Human placental multipotent mesenchymal stromal cells (hPMSCs) can be isolated from term placenta, but their angiogenic ability and the regulatory pathways involved are not known. hPMSCs were shown to express integrins αv, α4, α5, β1, β3, and β5 and could be induced to differentiate into cells expressing endothelial markers. Increases in cell surface integrins α5 and β1, but not α4, αvβ3, or αvβ5, accompanied endothelial differentiation. Vascular endothelial growth factor-A augmented the effect of fibronectin in enhancing adhesion and migration of differentiated hPMSC through integrin α5β1, but not αvβ3 or αvβ5. Formation of capillary-like structures in vitro from differentiated cells was inhibited by pre-treatment with function-blocking antibodies to integrins α5 and β1. When hPMSCs were seeded onto chick chorioallantoic membranes (CAM), human von Willebrand factor-positive cells were observed to engraft in the chick endothelium. CAMs transplanted with differentiated hPMSCs had a greater number of vessels containing human cells and more incorporated cells per vessel compared to CAMs transplanted with undifferentiated hPMSCs, and overall angiogenesis was enhanced more by the differentiated cells. Function-blocking antibodies to integrins α5 and β1 inhibited angiogenesis in the CAM assay. These results suggest that differentiated hPMSCs may contribute to blood vessel formation, and this activity depends on integrin α5β1

    Does speech rate influence intertemporal decisions? An experimental investigation

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    This paper experimentally examines the effect of speech rate on intertemporal decisions. In a delay-discounting task, subjects made a series of intertemporal choices between smaller-sooner and larger-delayed rewards and were asked to listen to a voice recording verbalizing the information for payoff options. We manipulated the speech rate of the voice recordings and administered two treatment conditions: Slow and Fast. We did not find an overall treatment effect in the acoustic manipulation.Ministry of Education (MOE)Published versionChen acknowledges financial support from the Ministry of Science and Technology of Taiwan (MOST 110-2628-H-002-009- and MOST 110-2634-F-002-045-) and the Ministry of Education of Taiwan (MOE 111L900203). He acknowledges financial support from the Ministry of Education of Singapore (MOE Academic Research Fund Tier 1 RG141/19)
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