129 research outputs found
PtdInsP(2) and PtdSer cooperate to trap synaptotagmin-1 to the plasma membrane in the presence of calcium.
The Ca2+-sensor synaptotagmin-1 that triggers neuronal exocytosis binds to negatively charged membrane lipids (mainly phosphatidylserine (PtdSer) and phosphoinositides (Ptdlns)) but the molecular details of this process are not fully understood. Using quantitative thermodynamic, kinetic and structural methods, we show that synaptotagmin-1 (from Rattus norvegicus and expressed in Escherichia coli) binds to Ptdlns(4,5)P-2 via a polybasic lysine patch in the C2B domain, which may promote the priming or docking of synaptic vesicles. Ca2+ neutralizes the negative charges of the Ca2+-binding sites, resulting in the penetration of synaptotagmin-1 into the membrane, via binding of PtdSer, and an increase in the affinity of the polybasic lysine patch to phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P-2). These Ca2+-induced events decrease the dissociation rate of synaptotagmin-1 membrane binding while the association rate remains unchanged. We conclude that both membrane penetration and the increased residence time of synaptotagmin-1 at the plasma membrane are crucial for triggering exocytotic membrane fusion
Schistosoma mansoni Egg-Released IPSE/alpha-1 Dampens Inflammatory Cytokine Responses via Basophil Interleukin (IL)-4 and IL-13
Schistosomes control inflammation in their hosts via highly effective mechanisms such as induction of Tregs, Bregs, and alternatively activated macrophages (AAMs). Notably, IPSE/alpha-1, the major secretory product from Schistosoma mansoni eggs, triggers basophils to release interleukin (IL)-4 and IL-13. Both cytokines are essential for AAM induction, suggesting an important role for IPSE/alpha-1 in inflammation control. Here, we show by in vitro co-culture experiments that IPSE/alpha-1-induced basophil IL-4/IL-13 inhibited pro-inflammatory cytokine release from human LPS-activated monocytes. This effect was cell/cell contact-independent but dependent on IL-4, since it was abrogated in the presence of anti-IL-4 antibodies. Importantly, the IPSE/alpha-1-induced IL-4/IL-13 release from basophils was amplified in the presence of LPS. Moreover, monocytes co-cultured in the presence of LPS with IPSE/alpha-1-stimulated basophils adopted an AAM-like phenotype as assessed by elevated expression of CD206 and CD209. The putative in vivo relevance of these findings was supported by immunohistological staining of S. mansoni-infected murine tissue revealing close physical contact between IPSE/alpha-1 and basophils in schistosome egg granulomas. Taken together, we found that IPSE/alpha-1 dampens inflammatory cytokine responses by triggering basophil IL-4/IL-13, in particular in the context of TLR activation, thereby turning inflammatory monocytes into anti-inflammatory AAMs. This might represent a mechanism used by schistosomes to control inflammation in the host
Restriction of meat, fish, and poultry in omnivores improves mood: A pilot randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Omnivorous diets are high in arachidonic acid (AA) compared to vegetarian diets. Research shows that high intakes of AA promote changes in brain that can disturb mood. Omnivores who eat fish regularly increase their intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), fats that oppose the negative effects of AA in vivo. In a recent cross-sectional study, omnivores reported significantly worse mood than vegetarians despite higher intakes of EPA and DHA. This study investigated the impact of restricting meat, fish, and poultry on mood.</p> <p>Findings</p> <p>Thirty-nine omnivores were randomly assigned to a control group consuming meat, fish, and poultry daily (OMN); a group consuming fish 3-4 times weekly but avoiding meat and poultry (FISH), or a vegetarian group avoiding meat, fish, and poultry (VEG). At baseline and after two weeks, participants completed a food frequency questionnaire, the Profile of Mood States questionnaire and the Depression Anxiety and Stress Scales. After the diet intervention, VEG participants reduced their EPA, DHA, and AA intakes, while FISH participants increased their EPA and DHA intakes. Mood scores were unchanged for OMN or FISH participants, but several mood scores for VEG participants improved significantly after two weeks.</p> <p>Conclusions</p> <p>Restricting meat, fish, and poultry improved some domains of short-term mood state in modern omnivores. To our knowledge, this is the first trial to examine the impact of restricting meat, fish, and poultry on mood state in omnivores.</p
Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults
<p>Abstract</p> <p>Background</p> <p>The physical health status of vegetarians has been extensively reported, but there is limited research regarding the mental health status of vegetarians, particularly with regard to mood. Vegetarian diets exclude fish, the major dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), critical regulators of brain cell structure and function. Omnivorous diets low in EPA and DHA are linked to impaired mood states in observational and experimental studies.</p> <p>Methods</p> <p>We examined associations between mood state and polyunsaturated fatty acid intake as a result of adherence to a vegetarian or omnivorous diet in a cross-sectional study of 138 healthy Seventh Day Adventist men and women residing in the Southwest. Participants completed a quantitative food frequency questionnaire, Depression Anxiety Stress Scale (DASS), and Profile of Mood States (POMS) questionnaires.</p> <p>Results</p> <p>Vegetarians (VEG:n = 60) reported significantly less negative emotion than omnivores (OMN:n = 78) as measured by both mean total DASS and POMS scores (8.32 ± 0.88 vs 17.51 ± 1.88, <it>p </it>= .000 and 0.10 ± 1.99 vs 15.33 ± 3.10, <it>p </it>= .007, respectively). VEG reported significantly lower mean intakes of EPA (<it>p </it>< .001), DHA (<it>p </it>< .001), as well as the omega-6 fatty acid, arachidonic acid (AA; <it>p </it>< .001), and reported higher mean intakes of shorter-chain α-linolenic acid (<it>p </it>< .001) and linoleic acid (<it>p </it>< .001) than OMN. Mean total DASS and POMS scores were positively related to mean intakes of EPA (<it>p </it>< 0.05), DHA (<it>p </it>< 0.05), and AA (<it>p </it>< 0.05), and inversely related to intakes of ALA (<it>p </it>< 0.05), and LA (<it>p </it>< 0.05), indicating that participants with low intakes of EPA, DHA, and AA and high intakes of ALA and LA had better mood.</p> <p>Conclusions</p> <p>The vegetarian diet profile does not appear to adversely affect mood despite low intake of long-chain omega-3 fatty acids.</p
Real-Time Self-Regulation of Emotion Networks in Patients with Depression
Many patients show no or incomplete responses to current pharmacological or psychological therapies for depression. Here we explored the feasibility of a new brain self-regulation technique that integrates psychological and neurobiological approaches through neurofeedback with functional magnetic resonance imaging (fMRI). In a proof-of-concept study, eight patients with depression learned to upregulate brain areas involved in the generation of positive emotions (such as the ventrolateral prefrontal cortex (VLPFC) and insula) during four neurofeedback sessions. Their clinical symptoms, as assessed with the 17-item Hamilton Rating Scale for Depression (HDRS), improved significantly. A control group that underwent a training procedure with the same cognitive strategies but without neurofeedback did not improve clinically. Randomised blinded clinical trials are now needed to exclude possible placebo effects and to determine whether fMRI-based neurofeedback might become a useful adjunct to current therapies for depression
Motivational modulation of bradykinesia in Parkinson's disease off and on dopaminergic medication.
Motivational influence on bradykinesia in Parkinson's disease may be observed in situations of emotional and physical stress, a phenomenon known as paradoxical kinesis. However, little is known about motivational modulation of movement speed beyond these extreme circumstances. In particular, it is not known if motivational factors affect movement speed by improving movement preparation/initiation or execution (or both) and how this effect relates to the patients' medication state. In the present study, we tested if provision of motivational incentive through monetary reward would speed-up movement initiation and/or execution in Parkinson's disease patients and if this effect depended on dopaminergic medication. We studied the effect of monetary incentive on simple reaction time in 11 Parkinson's disease patients both "off" and "on" dopaminergic medication and in 11 healthy participants. The simple reaction time task was performed across unrewarded and rewarded blocks. The initiation time and movement time were quantified separately. Anticipation errors and long responses were also recorded. The prospect of reward improved initiation times in Parkinson's disease patients both "off" and "on" dopaminergic medication, to a similar extent as in healthy participants. However, for "off" medication, this improvement was associated with increased frequency of anticipation errors, which were eliminated by dopamine replacement. Dopamine replacement had an additional, albeit small effect, on reward-related improvement of movement execution. Motivational strategies are helpful in overcoming bradykinesia in Parkinson's disease. Motivational factors may have a greater effect on bradykinesia when patients are "on" medication, as dopamine appears to be required for overcoming speed-accuracy trade-off and for improvement of movement execution. Thus, medication status should be an important consideration in movement rehabilitation programmes for patients with Parkinson's disease
The assessment of depression in people with multiple sclerosis : a systematic review of psychometric validation studies
Background: The prevalence of depression in people with multiple sclerosis (PwMS) is high; however, symptoms common to both conditions makes measurement difficult. There is no high quality overview of validation studies to guide the choice of depression inventory for this population.
Methods: A systematic review of studies validating the use of generic depression inventories in people with MS was conducted using MEDLINE and PsycINFO. Studies validating the use of depression inventories in PwMS and published in English were included; validation studies of tests for cognitive function and general mental health were excluded. Eligible studies were then quality assessed using the COSMIN checklist and findings synthesised narratively by instrument and validity domain.
Results: Twenty-one studies (N=5,991 PwMS) evaluating 12 instruments were included in the review. Risk of bias varied greatly between instrument and validity domain.
Conclusions: The review of validation studies was constrained by poor quality reporting and outcome reporting bias. Well-conducted evaluations of some instruments are unavailable for some validity domains. This systematic review provides an evidence base for trade-offs in the selection of an instrument for assessing self-reported symptoms of depression in research or clinical practice involving people with MS. We make detailed and specific recommendations for where further research is needed.
Registration: PROSPERO CRD42014010597
Keywords
Depression; Multiple Sclerosis; Reproducibility of Results; Psychometrics; Chronic Diseas
The use of Spielberger’s State-Trait Personality Inventory (trait anxiety subscale) with naval subaquatic specialists
Objectives: Panic behavior poses a particular threat to the health and safety of subaquatic occupational specialists. Trait anxiety has previously been identified as a marker of panic behavior under water, and Spielberger’s State-Trait Personality Inventory (trait anxiety subscale) has been previously used to measure trait anxiety among subaquatic specialists. Using archived data, the trait anxiety scores of subaquatic specialists were analyzed to meet 3 objectives: 1stly – to develop a trait anxiety profile of subaquatic specialists; 2ndly – to investigate the predictive value of trait anxiety measures upon entering an occupational field; and 3rdly – to establish the reliability of these scores over time. Material and Methods: Archival trait-anxiety data from 322 subjects were analyzed statistically. Results: Analysis of the available scores revealed a highly homogenous as well as a very low trait anxiety profile for the investigated occupational group. Additionally, low trait anxiety was somewhat associated with success during specialist training: fewer candidates with high trait anxiety scores completed their qualification. Moreover, measurement of trait anxiety was stable over time, which suggests that when scores for this occupational group are screened, deviations from previous scores could signify a potential need for referral to an intervention from health professionals. Conclusions: Using the trait anxiety subscale as part of occupational health surveillance of subaquatic specialists could support prevention of accidents by identifying high-risk candidates during their annual health assessments, and referral for timeous intervention
Dementia and Depression with Ischemic Heart Disease: A Population-Based Longitudinal Study Comparing Interventional Approaches to Medical Management
BACKGROUND: We compared the proportion of ischemic heart disease (IHD) patients newly diagnosed with dementia and depression across three treatment groups: percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and medical management alone (IHD-medical). METHODS AND FINDINGS: De-identified, individual-level administrative records of health service use for the population of Manitoba, Canada (approximately 1.1 million) were examined. From April 1, 1993 to March 31, 1998, patients were identified with a diagnosis of IHD (ICD-9-CM codes). Index events of CABG or PCI were identified from April 1, 1998 to March 31, 2003. Outcomes were depression or dementia after the index event. Patients were followed forward to March 31, 2006 or until censored. Proportional hazards regression analysis was undertaken. Independent variables examined were age, sex, diabetes, hypertension and income quintile, medical management alone for IHD, or intervention by PCI or CABG. Age, sex, diabetes, and presence of hypertension were all strongly associated with the diagnosis of depression and dementia. There was no association with income quintile. Dementia was less frequent with PCI compared to medical management; (HR = 0.65; p = 0.017). CABG did not provide the same protective effect compared to medical management (HR = 0.90; p = 0.372). New diagnosis depression was more frequent with interventional approaches: PCI (n = 626; hazard ratio = 1.25; p = 0.028) and CABG (n = 1124, HR = 1.32; p = 0.0001) than non-interventional patients (n = 34,508). Subsequent CABG was nearly 16-fold higher (p<0.0001) and subsequent PCI was 22-fold higher (p<0.0001) for PCI-managed than CABG-managed patients. CONCLUSIONS: Patients managed with PCI had the lowest likelihood of dementia-only 65% of the risk for medical management alone. Both interventional approaches were associated with a higher risk of new diagnosed depression compared to medical management. Long-term myocardial revascularization was superior with CABG. These findings suggest that PCI may confer a long-term protective effect from dementia. The mechanism(s) of dementia protection requires elucidation
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