933 research outputs found

    The transporter-like protein inebriated mediates hyperosmotic stimuli through intracellular signaling

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    We cloned the inebriated homologue MasIne from Manduca sexta and expressed it in Xenopus laevis oocytes. MasIne is homologous to neurotransmitter transporters but no transport was observed with a number of putative substrates. Oocytes expressing MasIne respond to hyperosmotic stimulation by releasing intracellular Ca(2+), as revealed by activation of the endogenous Ca(2+)-activated Cl(-) current. This Ca(2+) release requires the N-terminal 108 amino acid residues of MasIne and occurs via the inositol trisphosphate pathway. Fusion of the N terminus to the rat gamma-aminobutyric acid transporter (rGAT1) also renders rGAT1 responsive to hyperosmotic stimulation. Immunohistochemical analyses show that MasIne and Drosophila Ine have similar tissue distribution patterns, suggesting functional identity. Inebriated is expressed in tissues and cells actively involved in K(+) transport, which suggests that it may have a role in ion transport, particularly of K(+). We propose that stimulation of MasIne releases intracellular Ca(2+) in native tissues, activating Ca(2+)-dependent K(+) channels, and leading to K(+) transport

    Hijab and Muslim religious identity expression among Egyptian women in the Pacific Northwest

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    The purpose of this study was to examine the symbolic meaning of modest dress (referred to in a general sense as hijab) to Egyptian Muslim women living in America’s Pacific Northwest. In the diaspora, where Egyptian garments are not available, the women must mix headscarves with Western fashion, but it must be modest. Muslim women living in the USA need to integrate requirements for religious modesty when shopping for Western fashion which does not place a high value on modesty

    Short-term effects of a gain-focused reappraisal intervention for dementia caregivers: A double-blind cluster-randomized controlled trial

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    Objectives To examine the effects of a benefit-finding intervention, the key feature being the use of gain-focused reappraisal strategies to find positive meanings and benefits in caring for someone with dementia. Design: Cluster-randomized double-blind controlled trial. Setting: Social centers and clinics. Participants: 129 caregivers. Inclusion criteria were (a) primary caregiver aged 18+ and without cognitive impairment, (b) providing ≥14 care hours per week to a relative with mild-to-moderate Alzheimer's disease, and (c) scoring ≥3 on the Hamilton Depression Rating Scale. Exclusion criterion was care-recipient having parkinsonism or other forms of dementia. Interventions: The benefit-finding intervention was evaluated against two treatment-as-usuals, namely, simplified psychoeducation (lectures only) and standard psychoeducation. Each intervention lasted eight weeks, with a 2-hour session per week. Randomization into these conditions was based on center/clinic membership. Measurements: Primary outcome was depressive symptom. Secondary outcomes were Zarit Burden Interview, role overload, and psychological well-being. Self-efficacy beliefs and positive gains were treated as mediators. Measures were collected at baseline and posttreatment. Results: Regression analyses showed BF treatment effects on all outcomes when compared with SIM-PE, and effects on depressive symptoms and Zarit burden when compared with STD-PE. Effect sizes were medium-to-large for depressive symptoms (d=-0.77– -0.96), and medium for the secondary outcomes (d=|0.42–0.65|). Furthermore, using the bootstrapping method, we found significant mediating effects by self-efficacy in controlling upsetting thoughts and positive gains, with the former being the primary mediator. Conclusions: Finding positive gains reduces depressive symptoms and burden and promotes psychological well-being primarily through enhancing self-efficacy in controlling upsetting thoughts

    TMEM97 and PGRMC1 do not mediate sigma-2 ligand-induced cell death

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    Abstract Sigma-2 receptors have been implicated in both tumor proliferation and neurodegenerative diseases. Recently the sigma-2 receptor was identified as transmembrane protein 97 (TMEM97). Progesterone receptor membrane component 1 (PGRMC1) was also recently reported to form a complex with TMEM97 and the low density lipoprotein (LDL) receptor, and this trimeric complex is responsible for the rapid internalization of LDL. Sigma-2 receptor ligands with various structures have been shown to induce cell death in cancer cells. In the current study, we examined the role of TMEM97 and PGRMC1 in mediating sigma-2 ligand-induced cell death. Cell viability and caspase-3 assays were performed in control, TMEM97 knockout (KO), PGRMC1 KO, and TMEM97/PGRMC1 double KO cell lines treated with several sigma-2 ligands. The data showed that knockout of TMEM97, PGRMC1, or both did not affect the concentrations of sigma-2 ligands that induced 50% of cell death (EC50), suggesting that cytotoxic effects of these compounds are not mediated by TMEM97 or PGRMC1. Sigma-1 receptor ligands, (+)-pentazocine and NE-100, did not block sigma-2 ligand cytotoxicity, suggesting that sigma-1 receptor was not responsible for sigma-2 ligand cytotoxicity. We also examined whether the alternative, residual binding site (RBS) of 1,3-Di-o-tolylguanidine (DTG) could be responsible for sigma-2 ligand cytotoxicity. Our data showed that the binding affinities (K i) of sigma-2 ligands on the DTG RBS did not correlate with the cytotoxicity potency (EC50) of these ligands, suggesting that the DTG RBS was not fully responsible for sigma-2 ligand cytotoxicity. In addition, we showed that knocking out TMEM97, PGRMC1, or both reduced the initial internalization rate of a sigma-2 fluorescent ligand, SW120. However, concentrations of internalized SW120 became identical later in the control and knockout cells. These data suggest that the initial internalization process of sigma-2 ligands does not appear to mediate the cell-killing effect of sigma-2 ligands. In summary, we have provided evidence that sigma-2 receptor/TMEM97 and PGRMC1 do not mediate sigma-2 ligand cytotoxicity. Our work will facilitate elucidating mechanisms of sigma-2 ligand cytotoxicity

    Role of myosin light chain kinase in intestinal epithelial barrier defects in a rat model of bowel obstruction

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    <p>Abstract</p> <p>Background</p> <p>Bowel obstruction is a common cause of abdominal emergency, since the patients are at increased risk of septicemia resulting in high mortality rate. While the compartmentalized changes in enteric microfloral population and augmentation of bacterial translocation (BT) have already been reported using experimental obstruction models, alterations in epithelial permeability of the obstructed guts has not been studied in detail. Myosin light chain kinase (MLCK) is actively involved in the contraction of epithelial perijunctional actinomyosin ring and thereby increases paracellular permeability. In the current study we attempt to investigate the role of MLCK in epithelial barrier defects using a rat model of simple mechanical obstruction.</p> <p>Methods</p> <p>Wistar rats received intraperitoneal injection of ML-7 (a MLCK inhibitor) or vehicle at 24, 12 and 1 hrs before and 12 hrs after intestinal obstruction (IO). The distal small intestine was obstructed with a single ligature placed 10 cm proximal to the ileocecal junction in IO rats for 24 hrs. Sham-operated rats served as controls.</p> <p>Results</p> <p>Mucosal injury, such as villous blunting and increased crypt/villus ratio, was observed in the distal small intestine of IO rats. Despite massive enterocyte shedding, intestinal villi were covered with a contiguous epithelial layer without cell apoptosis. Increased transmural macromolecular flux was noticed in the distal small intestine and the proximal colon after IO. The bacterial colony forming units in the spleen and liver of IO rats were significantly higher than those of sham controls. Addition of ML-7 ameliorated the IO-triggered epithelial MLC phosphorylation, mucosal injury and macromolecular flux, but not the level of BT.</p> <p>Conclusions</p> <p>The results suggest that IO-induced premature enterocytic sloughing and enhanced paracellular antigenic flux were mediated by epithelial MLCK activation. In addition, enteric bacteria may undergo transcytotic routes other than paracellular paths to cross the epithelium.</p

    Relationship between cortical thickness and neuropsychological performance in normal older adults and those with mild cognitive impairment

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    Mild cognitive impairment (MCI) has been extensively investigated in recent decades to identify groups with a high risk of dementia and to establish effective prevention methods during this period. Neuropsychological performance and cortical thickness are two important biomarkers used to predict progression from MCI to dementia. This study compares the cortical thickness and neuropsychological performance in people with MCI and cognitively healthy older adults. We further focus on the relationship between cortical thickness and neuropsychological performance in these two groups. Forty-nine participants with MCI and 40 cognitively healthy older adults were recruited. Cortical thickness was analysed with semiautomatic software, Freesurfer. The analysis reveals that the cortical thickness in the left caudal anterior cingulate (p=0.041), lateral occipital (p=0.009) and right superior temporal (p=0.047) areas were significantly thinner in the MCI group after adjustment for age and education. Almost all neuropsychological test results (with the exception of forward digit span) were significantly correlated to cortical thickness in the MCI group after adjustment for age, gender and education. In contrast, only the score on the Category Verbal Fluency Test and the forward digit span were found to have significant inverse correlations to cortical thickness in the control group of cognitively healthy older adults. The study results suggest that cortical thinning in the temporal region reflects the global change in cognition in subjects with MCI and may be useful to predict progression of MCI to Alzheimer's disease. The different pattern in the correlation of cortical thickness to the neuropsychological performance of patients with MCI from the healthy control subjects may be explained by the hypothesis of MCI as a disconnection syndrome

    A survey of Chinese herbal ingredients with liver protection activities

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    A literature survey was conducted on herbs, their preparations and ingredients with reported liver protection activities, in which a total of 274 different species and hundreds of active ingredients have been examined. These ingredients can be roughly classified into two categories according to their activities: (1) the main ingredients, such as silybin, osthole, coumarin, glycyrrhizin, saikosaponin A, schisandrin A, flavonoids; and (2) supporting substances, such as sugars, amino acids, resins, tannins and volatile oil. Among them, some active ingredients have hepatoprotective activities (e.g. anti-inflammatory, anticancer, antioxidant, immunomodulating and liver cirrhosis-regulating effects). Calculation of physicochemical parameters indicates that the main ingredients with negative and positive Elumo values possibly display their hepatoprotective effects through different mechanisms, such as antioxidative, anti-inflammatory and immunomodulating effects. As the combination of herbs may achieve some treatment effects synergistically and/or additively, it is common in Chinese medicine to use mixtures of various medicinal herbs with pharmacologically active compounds to have synergistic and/or additive effects, or to reduce harmful effects of some pharmacologically active compounds. In particular, the active compounds with Clog P around 2 are suitable for passive transport across membranes and accessible to the target sites. Thus, Elumo and Clog P values are good indicators among the calculated parameters
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