73 research outputs found

    Folding-competent and folding-defective forms of Ricin A chain have different fates following retrotranslocation from the endoplasmic reticulum

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    We report that a toxic polypeptide retaining the potential to refold upon dislocation from the endoplasmic reticulum (ER) to the cytosol (ricin A chain; RTA) and a misfolded version that cannot (termed RTAΔ), follow ER-associated degradation (ERAD) pathways in Saccharomyces cerevisiae that substantially diverge in the cytosol. Both polypeptides are dislocated in a step mediated by the transmembrane Hrd1p ubiquitin ligase complex and subsequently degraded. Canonical polyubiquitylation is not a prerequisite for this interaction because a catalytically inactive Hrd1p E3 ubiquitin ligase retains the ability to retrotranslocate RTA, and variants lacking one or both endogenous lysyl residues also require the Hrd1p complex. In the case of native RTA, we established that dislocation also depends on other components of the classical ERAD-L pathway as well as an ongoing ER–Golgi transport. However, the dislocation pathways deviate strikingly upon entry into the cytosol. Here, the CDC48 complex is required only for RTAΔ, although the involvement of individual ATPases (Rpt proteins) in the 19S regulatory particle (RP) of the proteasome, and the 20S catalytic chamber itself, is very different for the two RTA variants. We conclude that cytosolic ERAD components, particularly the proteasome RP, can discriminate between structural features of the same substrate

    Does methylphenidate improve inhibition and other cognitive abilities in adults with childhood-onset ADHD?

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    Contains fulltext : 48908.pdf (publisher's version ) (Closed access)We examined the effect of methylphenidate (Mph) on inhibition and several other cognitive abilities in 43 adults with Attention Deficit Hyperactivity Disorder (ADHD) by use of Conners' Continuous Performance Test (CPT) and the Change Task (ChT), an extension of the Stop Signal Test (SST). In a double blind, cross-over, placebo controlled study with Mph, tests were administered during the third week of individually titrated treatment with Mph (maximum dose 1 mg / kg / day) and during the third week of treatment with placebo. We established large medication effects for commission errors, standard error of mean reaction time, and attentiveness on the CPT, as well as moderate medication effects for mean reaction time on the CPT and response re-engagement speed on the ChT. For Stop Signal Reaction Time (SSRT) on the ChT, we also established large effects of Mph, but only in a group of participants who showed slow SSRTs on placebo. Mph indeed ameliorates inhibition, which is the core problem of ADHD, and certain other cognitive abilities in adults with ADHD

    Duloxetine compared with fluoxetine and venlafaxine: use of meta-regression analysis for indirect comparisons

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    BACKGROUND: Data comparing duloxetine with existing antidepressant treatments is limited. A comparison of duloxetine with fluoxetine has been performed but no comparison with venlafaxine, the other antidepressant in the same therapeutic class with a significant market share, has been undertaken. In the absence of relevant data to assess the place that duloxetine should occupy in the therapeutic arsenal, indirect comparisons are the most rigorous way to go. We conducted a systematic review of the efficacy of duloxetine, fluoxetine and venlafaxine versus placebo in the treatment of Major Depressive Disorder (MDD), and performed indirect comparisons through meta-regressions. METHODS: The bibliography of the Agency for Health Care Policy and Research and the CENTRAL, Medline, and Embase databases were interrogated using advanced search strategies based on a combination of text and index terms. The search focused on randomized placebo-controlled clinical trials involving adult patients treated for acute phase Major Depressive Disorder. All outcomes were derived to take account for varying placebo responses throughout studies. Primary outcome was treatment efficacy as measured by Hedge's g effect size. Secondary outcomes were response and dropout rates as measured by log odds ratios. Meta-regressions were run to indirectly compare the drugs. Sensitivity analysis, assessing the influence of individual studies over the results, and the influence of patients' characteristics were run. RESULTS: 22 studies involving fluoxetine, 9 involving duloxetine and 8 involving venlafaxine were selected. Using indirect comparison methodology, estimated effect sizes for efficacy compared with duloxetine were 0.11 [-0.14;0.36] for fluoxetine and 0.22 [0.06;0.38] for venlafaxine. Response log odds ratios were -0.21 [-0.44;0.03], 0.70 [0.26;1.14]. Dropout log odds ratios were -0.02 [-0.33;0.29], 0.21 [-0.13;0.55]. Sensitivity analyses showed that results were consistent. CONCLUSION: Fluoxetine was not statistically different in either tolerability or efficacy when compared with duloxetine. Venlafaxine was significantly superior to duloxetine in all analyses except dropout rate. In the absence of relevant data from head-to-head comparison trials, results suggest that venlafaxine is superior compared with duloxetine and that duloxetine does not differentiate from fluoxetine

    Advances in understanding and treating ADHD

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    Attention deficit hyperactivity disorder (ADHD) is a neurocognitive behavioral developmental disorder most commonly seen in childhood and adolescence, which often extends to the adult years. Relative to a decade ago, there has been extensive research into understanding the factors underlying ADHD, leading to far more treatment options available for both adolescents and adults with this disorder. Novel stimulant formulations have made it possible to tailor treatment to the duration of efficacy required by patients, and to help mitigate the potential for abuse, misuse and diversion. Several new non-stimulant options have also emerged in the past few years. Among these, cognitive behavioral interventions have proven popular in the treatment of adult ADHD, especially within the adult population who cannot or will not use medications, along with the many medication-treated patients who continue to show residual disability

    Prevalence of and associated factors for adult attention deficit hyperactivity disorder in young Swiss men.

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    OBJECTIVE: The present study aimed to measure the prevalence of adult attention deficit hyperactivity disorder (ADHD) in a large, representative sample of young Swiss men and to assess factors associated with this disorder. METHODS: Our sample consisted of 5656 Swiss men (mean age 20 years) who participated in the Cohort Study on Substance Use Risk Factors (C-SURF). ADHD was assessed with the World Health Organization (WHO) adult ADHD Self Report Screener (ASRS). Logistic regression analyses were conducted to assess the association between ADHD and several socio-demographic, clinical and familial factors. RESULTS: The prevalence of ADHD was 4.0%, being higher in older and French-speaking conscripts. A higher prevalence also was identified among men whose mothers had completed primary or high school/university and those with a family history of alcohol or psychiatric problems. Additionally, adults with ADHD demonstrated impairment in their professional life, as well as considerable mental health impairment. CONCLUSION: Our results demonstrate that ADHD is common among young Swiss men. The impairments in function and mental health we observed highlight the need for further support and interventions to reduce burden in affected individuals. Interventions that incorporate the whole family also seem crucial
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