2,041 research outputs found
In vitro investigation of the hypoglycemic activity of yeasts using models of rat epididymal adipocyte and differentiated mouse 3T3-L1 adipocyte
The differentiated mouse 3T3-L1 adipocytes (3T3-L1 model) were used in studying glucose metabolisms without the need for feeding (Sprague-Dawley, SD model) the rat prior to hypoglycemic activity evaluation. Both models were adopted to evaluate the hypoglycemic activities of 58 yeast strains isolated from various sources (grape, vine yard soil, winery soil). Among the 58 tested yeast isolates, strain 54 (Saccharomyces pastorianus no. 54) which showed the highest hypoglycemic activity was chosen to be the test strain. The optimal insulin concentration used in these 2 models (SD and 3T3-L1) for measuring the hypoglycemic activity of hypoglycemic yeast extract (HGYE) was 10 nM. The range of linear relation in the dose-response curve was 0-1000 g/ml for SD model, and 0-250 g/ml for 3T3-L1 model. The linear coefficient was 0.8611. The radioactive labeled 2-[1-14C]-Deoxy-D-Glucose was also used to confirm cytoplasmic glucose uptake by 3T3-L1 adipocytes. Comparing both the results of insulin effect and dose response of HGYE by both models, it was concluded that the 3T3-L1 model can serve as a rapid and reliable assay model for in vitro evaluation of hypoglycemic activity of yeast.Key words: 3T3-L1 adipocytes, Sprague-Dawley (SD) rat, epididymal adipocytes, hypoglycemic activity, yeast
Sample entropy analysis of EEG signals via artificial neural networks to model patients' consciousness level based on anesthesiologists experience.
Electroencephalogram (EEG) signals, as it can express the human brain's activities and reflect awareness, have been widely used in many research and medical equipment to build a noninvasive monitoring index to the depth of anesthesia (DOA). Bispectral (BIS) index monitor is one of the famous and important indicators for anesthesiologists primarily using EEG signals when assessing the DOA. In this study, an attempt is made to build a new indicator using EEG signals to provide a more valuable reference to the DOA for clinical researchers. The EEG signals are collected from patients under anesthetic surgery which are filtered using multivariate empirical mode decomposition (MEMD) method and analyzed using sample entropy (SampEn) analysis. The calculated signals from SampEn are utilized to train an artificial neural network (ANN) model through using expert assessment of consciousness level (EACL) which is assessed by experienced anesthesiologists as the target to train, validate, and test the ANN. The results that are achieved using the proposed system are compared to BIS index. The proposed system results show that it is not only having similar characteristic to BIS index but also more close to experienced anesthesiologists which illustrates the consciousness level and reflects the DOA successfully.This research is supported by the Center forDynamical Biomarkers and Translational Medicine, National Central University, Taiwan, which is sponsored by Ministry of Science and Technology (Grant no. MOST103-2911-I-008-001). Also, it is supported by National Chung-Shan Institute of Science & Technology in Taiwan (Grant nos. CSIST-095-V301 and CSIST-095-V302)
Improving Fluid Intelligence With Training on Working Memory: A Meta-Analysis
Working memory (WM), the ability to store and manipulate information for short periods of time, is an important predictor of scholastic aptitude and a critical bottleneck underlying higher-order cognitive processes, including controlled attention and reasoning. Recent interventions targeting WM have suggested plasticity of the WM system by demonstrating improvements in both trained and untrained WM tasks. However, evidence on transfer of improved WM into more general cognitive domains such as fluid intelligence (Gf) has been more equivocal. Therefore, we conducted a meta-analysis focusing on one specific training program, n-back. We searched PubMed and Google Scholar for all n-back training studies with Gf outcome measures, a control group, and healthy participants between 18 and 50 years of age. In total, we included 20 studies in our analyses that met our criteria and found a small but significant positive effect of n-back training on improving Gf. Several factors that moderate this transfer are identified and discussed. We conclude that short-term cognitive training on the order of weeks can result in beneficial effects in important cognitive functions as measured by laboratory tests
Serotonin and corticosterone rhythms in mice exposed to cigarette smoke and in patients with COPD:implication for COPD-associated neuropathogenesis
The circadian timing system controls daily rhythms of physiology and behavior, and disruption of clock function can trigger stressful life events. Daily exposure to cigarette smoke (CS) can lead to alteration in diverse biological and physiological processes. Smoking is associated with mood disorders, including depression and anxiety. Patients with chronic obstructive pulmonary disease (COPD) have abnormal circadian rhythms, reflected by daily changes in respiratory symptoms and lung function. Corticosterone (CORT) is an adrenal steroid that plays a considerable role in stress and anti-inflammatory responses. Serotonin (5-hydroxytryptamine; 5HT) is a neurohormone, which plays a role in sleep/wake regulation and affective disorders. Secretion of stress hormones (CORT and 5HT) is under the control of the circadian clock in the suprachiasmatic nucleus. Since smoking is a contributing factor in the development of COPD, we hypothesize that CS can affect circadian rhythms of CORT and 5HT secretion leading to sleep and mood disorders in smokers and patients with COPD. We measured the daily rhythms of plasma CORT and 5HT in mice following acute (3 d), sub-chronic (10 d) or chronic (6 mo) CS exposure and in plasma from non-smokers, smokers and patients with COPD. Acute and chronic CS exposure affected both the timing (peak phase) and amplitude of the daily rhythm of plasma CORT and 5HT in mice. Acute CS appeared to have subtle time-dependent effects on CORT levels but more pronounced effects on 5HT. As compared with CORT, plasma 5HT was slightly elevated in smokers but was reduced in patients with COPD. Thus, the effects of CS on plasma 5HT were consistent between mice and patients with COPD. Together, these data reveal a significant impact of CS exposure on rhythms of stress hormone secretion and subsequent detrimental effects on cognitive function, depression-like behavior, mood/anxiety and sleep quality in smokers and patients with COPD
Assessing Internet addiction using the parsimonious Internet addiction components model - a preliminary study [forthcoming]
Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffithsβ addiction components (2005), including salience, mood modification, tolerance, withdrawal, conflict, and relapse. Two validated measures of Internet addiction were used (Compulsive Internet Use Scale [CIUS], Meerkerk et al., 2009, and Assessment for Internet and Computer Game Addiction Scale [AICA-S], Beutel et al., 2010) in two independent samples (ns = 3,105 and 2,257). The fit of the model was analysed using Confirmatory Factor Analysis. Results indicate that the Internet addiction components model fits the data in both samples well. The two sample/two instrument approach provides converging evidence concerning the degree to which the components model can organize the self-reported behavioural components of Internet addiction. Recommendations for future research include a more detailed assessment of tolerance as addiction component
Modulation of gene-specific epigenetic states and transcription by non-coding RNAs
Emerging evidence points to a role for long non-coding RNAs in the modulation of epigenetic states and transcription in human cells. New insights, using various forms of small non-coding RNAs, suggest that a mechanism of action is operative in human cells, which utilizes non-coding RNAs to direct epigenetic marks to homology containing loci resulting ultimately in the epigenetic-based modulation of gene transcription. Importantly, insights into this mechanism of action have allowed for certain target sequences, which are either actively involved in RNA mediated epigenetic regulation or targets for non-coding RNA based epigenetic regulation, to be selected. As such, it is now feasible to utilize small antisense RNAs to either epigenetically silence a gene expression or remove epigenetic silencing of endogenous non-coding RNAs and essentially turn on a gene expression. Knowledge of this emerging RNA-based epigenetic regulatory network and our ability to cognitively control gene expression has deep implications in the development of an entirely new area of pharmacopeia
Small but crucial : the novel small heat shock protein Hsp21 mediates stress adaptation and virulence in Candida albicans
Peer reviewedPublisher PD
Cyclophilin A interacts with diverse lentiviral capsids
BACKGROUND: The capsid (CA) protein of HIV-1 binds with high affinity to the host protein cyclophilin A (CypA). This binding positively affects some early stage of the viral life-cycle because prevention of binding either by drugs that occupy that active site of cyclophilin A, by mutation in HIV-1 CA, or RNAi that knocks down intracellular CypA level diminishes viral infectivity. The closely related lentivirus, SIVcpz also binds CypA, but it was thought that this interaction was limited to the HIV-1/SIVcpz lineage because other retroviruses failed to interact with CypA in a yeast two-hybrid assay. RESULTS: We find that diverse lentiviruses, FIV and SIVagmTAN also bind to CypA. Mutagenesis of FIV CA showed that an amino acid that is in a homologous position to the proline at amino acid 90 of HIV-1 CA is essential for FIV interactions with CypA. CONCLUSION: These results demonstrate that CypA binding to lentiviruses is more widespread than previously thought and suggest that this interaction is evolutionarily important for lentiviral infection
Linkage to HIV care, postpartum depression, and HIV-related stigma in newly diagnosed pregnant women living with HIV in Kenya: a longitudinal observational study
BACKGROUND: While studies have suggested that depression and HIV-related stigma may impede access to care, a growing body of literature also suggests that access to HIV care itself may help to decrease internalized HIV-related stigma and symptoms of depression in the general population of persons living with HIV. However, this has not been investigated in postpartum women living with HIV. Furthermore, linkage to care itself may have additional impacts on postpartum depression beyond the effects of antiretroviral therapy. We examined associations between linkage to HIV care, postpartum depression, and internalized stigma in a population with a high risk of depression: newly diagnosed HIV-positive pregnant women. METHODS: In this prospective observational study, data were obtained from 135 HIV-positive women from eight antenatal clinics in the rural Nyanza Province of Kenya at their first antenatal visit (prior to testing HIV-positive for the first time) and subsequently at 6Β weeks after giving birth. RESULTS: At 6Β weeks postpartum, women who had not linked to HIV care after testing positive at their first antenatal visit had higher levels of depression and internalized stigma, compared to women who had linked to care. Internalized stigma mediated the effect of linkage to care on depression. Furthermore, participants who had both linked to HIV care and initiated antiretroviral therapy reported the lowest levels of depressive symptoms. CONCLUSIONS: These results provide further support for current efforts to ensure that women who are newly diagnosed with HIV during pregnancy become linked to HIV care as early as possible, with important benefits for both physical and mental health
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