English in Indonesian Islamic Higher Education: Examining the Relationship Between Performance in the Yes/no Test and Reading Skills

This study examines the relationship between performance in the Yes/No test of English recognition vocabulary and reading skills in Indonesian Islamic learners of English as a foreign language (EFL). Participants in the study were 83 Indonesian undergraduate students, comprising an Advanced group (n=41) and Intermediate group (n=42) of EFL learners enrolled in the English department at the State Islamic University (UIN) of Malang, Indonesia. All participants completed both tests. The results reveal that the hits accuracy performance between the Advanced EFL group and the Intermediate EFL group was statistically significant, indicating that Yes/No test performance, in context of hits accuracy, did discriminate between levels of English proficiency. However, the differences disappeared with corrected scores since both groups indicated a high false alarm rate. In addition, this study also reveals that there was no evidence of a relationship between Yes/No performance and reading scores. Several pedagogical implications for EFL language teachers are discussed

Effect of Peripheral 5-HT on Glucose and Lipid Metabolism in Wether Sheep

In mice, peripheral 5-HT induces an increase in the plasma concentrations of glucose, insulin and bile acids, and a decrease in plasma triglyceride, NEFA and cholesterol concentrations. However, given the unique characteristics of the metabolism of ruminants relative to monogastric animals, the physiological role of peripheral 5-HT on glucose and lipid metabolism in sheep remains to be established. Therefore, in this study, we investigated the effect of 5-HT on the circulating concentrations of metabolites and insulin using five 5-HT receptor (5HTR) antagonists in sheep. After fasting for 24 h, sheep were intravenously injected with 5-HT, following which-, plasma glucose, insulin, triglyceride and NEFA concentrations were significantly elevated. In contrast, 5-HT did not affect the plasma cholesterol concentration, and it induced a decrease in bile acid concentrations. Increases in plasma glucose and insulin concentrations induced by 5-HT were attenuated by pre-treatment with Methysergide, a 5HTR 1, 2 and 7 antagonist. Additionally, decreased plasma bile acid concentrations induced by 5-HT were blocked by pre-treatment with Ketanserin, a 5HTR 2A antagonist. However, none of the 5HTR antagonists inhibited the increase in plasma triglyceride and NEFA levels induced by 5-HT. On the other hand, mRNA expressions of 5HTR1D and 1E were observed in the liver, pancreas and skeletal muscle. These results suggest that there are a number of differences in the physiological functions of peripheral 5-HT with respect to lipid metabolism between mice and sheep, though its effect on glucose metabolism appears to be similar between these species

Selective inhibition by ethanol of mitochondrial calcium influx mediated by uncoupling protein-2 in relation to N-methyl-D-aspartate cytotoxicity in cultured neurons.

BACKGROUND: We have shown the involvement of mitochondrial uncoupling protein-2 (UCP2) in the cytotoxicity by N-methyl-D-aspartate receptor (NMDAR) through a mechanism relevant to the increased mitochondrial Ca(2+) levels in HEK293 cells with acquired NMDAR channels. Here, we evaluated pharmacological profiles of ethanol on the NMDA-induced increase in mitochondrial Ca(2+) levels in cultured murine neocortical neurons. METHODOLOGY/PRINCIPAL FINDINGS: In neurons exposed to glutamate or NMDA, a significant increase was seen in mitochondrial Ca(2+) levels determined by Rhod-2 at concentrations of 0.1 to 100 µM. Further addition of 250 mM ethanol significantly inhibited the increase by glutamate and NMDA in Rhod-2 fluorescence, while similarly potent inhibition of the NMDA-induced increase was seen after exposure to ethanol at 50 to 250 mM in cultured neurons. Lentiviral overexpression of UCP2 significantly accelerated the increase by NMDA in Rhod-2 fluorescence in neurons, without affecting Fluo-3 fluorescence for intracellular Ca(2+) levels. In neurons overexpressing UCP2, exposure to ethanol resulted in significantly more effective inhibition of the NMDA-induced increase in mitochondrial free Ca(2+) levels than in those without UCP2 overexpression, despite a similarly efficient increase in intracellular Ca(2+) levels irrespective of UCP2 overexpression. Overexpression of UCP2 significantly increased the number of dead cells in a manner prevented by ethanol in neurons exposed to glutamate. In HEK293 cells with NMDAR containing GluN2B subunit, more efficient inhibition was similarly induced by ethanol at 50 and 250 mM on the NMDA-induced increase in mitochondrial Ca(2+) levels than in those with GluN2A subunit. Decreased protein levels of GluN2B, but not GluN2A, subunit were seen in immunoprecipitates with UCP2 from neurons with brief exposure to ethanol at concentrations over 50 mM. CONCLUSIONS/SIGNIFICANCE: Ethanol could inhibit the interaction between UCP2 and NMDAR channels to prevent the mitochondrial Ca(2+) incorporation and cell death after NMDAR activation in neurons

Potential interactions of calcium-sensitive reagents with zinc ion in different cultured cells.

Several chemicals have been widely used to evaluate the involvement of free Ca(2+) in mechanisms underlying a variety of biological responses for decades. Here, we report high reactivity to zinc of well-known Ca(2+)-sensitive reagents in diverse cultured cells.In rat astrocytic C6 glioma cells loaded with the fluorescent Ca(2+) dye Fluo-3, the addition of ZnCl2 gradually increased the fluorescence intensity in a manner sensitive to the Ca(2+) chelator EGTA irrespective of added CaCl2. The addition of the Ca(2+) ionophore A23187 drastically increased Fluo-3 fluorescence in the absence of ZnCl2, while the addition of the Zn(2+) ionophore pyrithione rapidly and additionally increased the fluorescence in the presence of ZnCl2, but not in its absence. In cells loaded with the zinc dye FluoZin-3 along with Fluo-3, a similarly gradual increase was seen in the fluorescence of Fluo-3, but not of FluoZin-3, in the presence of both CaCl2 and ZnCl2. Further addition of pyrithione drastically increased the fluorescence intensity of both dyes, while the addition of the Zn(2+) chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine (TPEN) rapidly and drastically decreased FluoZin-3 fluorescence. In cells loaded with FluoZin-3 alone, the addition of ZnCl2 induced a gradual increase in the fluorescence in a fashion independent of added CaCl2 but sensitive to EGTA. Significant inhibition was found in the vitality to reduce 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide in a manner sensitive to TPEN, EDTA and BAPTA in C6 glioma cells exposed to ZnCl2, with pyrithione accelerating the inhibition. Similar inhibition occurred in an EGTA-sensitive fashion after brief exposure to ZnCl2 in pluripotent P19 cells, neuronal Neuro2A cells and microglial BV2 cells, which all expressed mRNA for particular zinc transporters.Taken together, comprehensive analysis is absolutely required for the demonstration of a variety of physiological and pathological responses mediated by Ca(2+) in diverse cells enriched of Zn(2+)

Promotion of both proliferation and neuronal differentiation in pluripotent P19 cells with stable overexpression of the glutamine transporter slc38a1.

BACKGROUND: We previously demonstrated the functional expression in newborn rat neocortical astrocytes of glutamine transporter (GlnT = slc38a1) believed to predominate in neurons over astroglia in the brain. In order to evaluate the possible role of this transporter in neurogenesis, we attempted to establish stable transfectants of GlnT in mouse embryonal carcinoma P19 cells endowed to proliferate for self-renewal and differentiate into progeny cells such as neurons and astroglia, in addition to in vitro pharmacological profiling of the green tea ingredient theanine, which is shown to be a potent inhibitor of glutamine transport mediated by GlnT in cultured neurons and astroglia. METHODOLOGY/PRINCIPAL FINDINGS: The full-length coding region of rat GlnT was inserted into a vector for gene transfection along with selection by G418, followed by culture with all-trans retinoic acid under floating conditions and subsequent dispersion for spontaneous differentiation under adherent conditions. Stable overexpression of GlnT led to marked increases in the size of round spheres formed during the culture for 4 days and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide reduction, with concomitant promotion of subsequent differentiation into cells immunoreactive for a neuronal marker protein. In these stable GlnT transfectants before differentiation, drastic upregulation was seen for mRNA expression of several proneural genes with a basic helix-loop-helix domain such as NeuroD1. Although a drastic increase was seen in NeuroD1 promoter activity in stable GlnT transfectants, theanine doubled NeuroD1 promoter activity in stable transfectants of empty vector (EV), without affecting the promoter activity already elevated in GlnT transfectants. Similarly, theanine promoted cellular proliferation and neuronal differentiation in stable EV transfectants, but failed to further stimulate the acceleration of both proliferation and neuronal differentiation found in stable GlnT transfectants. CONCLUSIONS/SIGNIFICANCE: GlnT would promote both proliferation and neuronal differentiation through a mechanism relevant to the upregulation of particular proneural genes in undifferentiated P19 cells

Effects of ZnCl₂ on FluoZin-3 fluorescence in C6 glioma cells.

<p>(A) C6 glioma cells were loaded with FluoZin-3 in either the presence or absence of CaCl_<b>2</b>, followed by determination of the fluorescence intensity in the presence of ZnCl_<b>2</b> every 1 min. (B) Cells were loaded with FluoZin-3 in the presence of either EGTA or CaCl_<b>2</b>, followed by determination of the fluorescence intensity in the presence of ZnCl_<b>2</b> every 1 min. Values are the mean±S.E. of the rate of fluorescence change in 3 different experiments.</p

A selective increase by ZnCl₂ in Fluo-3 fluorescence in C6 glioma cells.

<p>(A) Cells were loaded with Fluo-3 in the presence of CaCl_<b>2</b>, followed by determination of the fluorescence intensity in either the presence or absence of ZnCl_<b>2</b> and FeCl_<b>2</b> every 1 min. Cells were exposed to ATP at different concentrations during the determination of fluorescence. (B) Cells were loaded with Fluo-3 in the presence of either EGTA or CaCl_<b>2</b>, followed by determination of the fluorescence intensity in the presence of ZnCl_<b>2</b> every 1 min. Values are the mean±S.E. of the rate of fluorescence change in 3 different experiments.</p

Effects of ZnCl₂ on MTT reducing activity in different cell lines.

<p>Cells were exposed to ZnCl_<b>2</b> at 0.1 or 1 mM in either the presence or absence of CaCl_<b>2</b> and EGTA for 1 h, followed by culture for an additional 24 h and subsequent determination of MTT reducing activity. Values are the mean±S.E. of percentages over the maximal activity detected in cells not exposed to any test chemicals in 3 different experiments. *P<0.05, **P<0.01, significantly different from the control value in cells not exposed to ZnCl₂. ^#P<0.05, ^#P<0.01, significantly different from the value in cells exposed to ZnCL₂ at each concentration.</p

Effects of TPEN on Fluo-3 and Rhod-2 fluorescence in HEK293 cells with acquired NMDAR channels.

<p>HEK293 cells were transfected with expression vectors of GluNR1 and GluNR2A, followed by further culture for an additional 24 h and subsequent loading of either (A) Fluo-3 or (B) Rhod-2 in the presence of Gly. Cells were then exposed to Glu in either the presence or absence of TPEN during the determination of each fluorescence intensity every 1 min. Values are the mean±S.E. of the rate of fluorescence change in 3 different experiments.</p

Effects of ZnCl₂ on MTT reducing activity in C6 glioma cells.

<p>Cells were exposed to ZnCl_<b>2</b> at different concentrations in either the presence or absence of TPEN, pyrithione, BAPTA and EDTA for 1 h, followed by culture for an additional 6 h and subsequent determination of MTT reducing activity. Values are the mean±S.E. of percentages over the maximal activity detected in cells not exposed to any test chemicals in 3 different experiments. *P<0.05, **P<0.01, significantly different from the control value in cells not exposed to ZnCl₂. ^#P<0.05, ^#P<0.01, significantly different from the value in cells exposed to ZnCL₂ at each concentration.</p