179 research outputs found

    Induction of the CtsR regulon improves Xylanase production in <i>Bacillus subtilis</i>

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    Background The bacterium Bacillus subtilis is extensively used for the commercial production of enzymes due to its efficient protein secretion capacity. However, the efficiency of secretion varies greatly between enzymes, and despite many years of research, optimization of enzyme production is still largely a matter of trial-and-error. Genome-wide transcriptome analysis seems a useful tool to identify relevant secretion bottlenecks, yet to this day, only a limited number of transcriptome studies have been published that focus on enzyme secretion in B. subtilis. Here, we examined the effect of high-level expression of the commercially important enzyme endo-1,4-β-xylanase XynA on the B. subtilis transcriptome using RNA-seq.Results  Using the novel gene-set analysis tool GINtool, we found a reduced activity of the CtsR regulon when XynA was overproduced. This regulon comprises several protein chaperone genes, including clpC, clpE and clpX, and is controlled by transcriptional repression. CtsR levels are directly controlled by regulated proteolysis, involving ClpC and its cognate protease ClpP. When we abolished this negative feedback, by inactivating the repressor CtsR, the XynA production increased by 25%.Conclusions Overproduction of enzymes can reduce the pool of Clp protein chaperones in B. subtilis, presumably due to negative feedback regulation. Breaking this feedback can improve enzyme production yields. Considering the conserved nature of Clp chaperones and their regulation, this method might benefit high-yield enzyme production in other organisms

    Dissociative symptoms and sleep parameters: an all-night polysomnography study in patients with insomnia

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    AbstractBackgroundDissociative disorders encompass a range of symptoms varying from severe absent-mindedness and memory problems to confusion about one's own identity. Recent studies suggest that these symptoms may be the by-products of a labile sleep–wake cycle.MethodsIn the current study, we explored this issue in patients suffering from insomnia (N=46). We investigated whether these patients have raised levels of dissociative symptoms and whether these are related to objective sleep parameters. Patients stayed for at least one night in a specialized sleep clinic, while sleep EEG data were obtained. In addition, they completed self-report measures on dissociative symptoms, psychological problems, and sleep characteristics.ResultsDissociative symptom levels were elevated in patients suffering from insomnia, and were correlated with unusual sleep experiences and poor sleep quality. Longer REM sleep periods and less time spent awake during the night were predictive of dissociation.ConclusionsThis is the first study to show that insomnia patients have raised dissociative symptom levels and that their dissociative symptoms are related to objective EEG parameters. These findings are important because they may inspire sleep-related treatment methods for dissociative disorders

    A longitudinal follow-up study of parent-reported family impact and quality of life in young patients with traumatic and non-traumatic brain injury

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    PurposeBrain injuries (traumatic-/nontraumatic, TBI/nTBI) in young patients may lead to problems e.g., decreased health-related quality of life (HRQoL), and causes family impact. Knowledge regarding the family impact and the relationship with patients' HRQoL over time is scarce. This follow-up study describes family impact/HRQoL and their mutual relationship in young patients (5-24 years) after TBI/nTBI.Materials and methodsParents of patients that were referred to outpatient rehabilitation completed the PedsQL (TM) Family-Impact-Module questionnaire to assess the family impact and the parent-reported PedsQL (TM) Generic-core-set-4.0 to assess patients' HRQoL (lower scores: more family impact/worse HRQoL). Questionnaires were completed at the time of referral to rehabilitation (baseline) and one/two years later (T1/T2). Linear-mixed models were used to examine family impact/HRQoL change scores, and repeated-measure correlations (r) to determine longitudinal relationships.ResultsTwo-hundred-forty-six parents participated at baseline, 72 (at T2), median patient's age at baseline was 14 years (IQR:11-16), and 181 (74%) had TBI. Mean (SD) PedsQL (TM) Family-Impact-Module score at baseline was 71.7 (SD:16.4) and PedsQL (TM) Generic-core-set-4.0: 61.4 (SD:17.0). Over time, PedsQL (TM) Family-Impact-Module scores remained stable, while PedsQL (TM) Generic-core-set-4.0 scores improved significantly(p < 0.05). A moderately strong longitudinal correlation was found between family impact&HRQoL (r = 0.51).ConclusionsFamily impact does not tend to decrease over time but remained a considerable problem, although patients' HRQoL improved. Next to focusing on patients' HRQoL, it remains important to consider family impact and offer family support throughout rehabilitation.</p

    Fatigue in young patients with acquired brain injury in the outpatient rehabilitation setting: a 2-year follow-up study

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    Acquired brain injury (ABI) may cause fatigue and participation restrictions in young patients. However, knowledge regarding the course of these problems over time is lacking. This study aims to describe the course of fatigue and participation and their relationship over time in an observational two-year follow-up study among patients(5-24 years) with ABI referred for outpatient rehabilitation and their parents. Patients/parents completed the PedsQL (TM) Multidimensional-Fatigue-Scale(PedsQL (TM) MFS, totalscore/3-domains) and the Child/Adolescent-Scale of Participation(CASP, totalscore/4-domains). Scores ranged from 0-100: lower scores = more fatigue/participation problems. Linear mixed models and repeated measures correlations were used to determine the course over time (change-scores/95%CI) and correlations between fatigue/participation. At baseline, 223 patients/246 parents participated with 94/104 at either T1, T2 or both. Median age was 15 years (IQR:12-17), 74% had a traumatic brain injury. Mean(SD) patient/parent-reported PedsQL (TM) MFS totalscores(baseline) were: 50.3(17.3) and 53.8(19.1), respectively. CASP totalscores were 78.0(16.4) and 87.1(13.6). Over time, patient-reported scores improved significantly (fatigue: + 8.8 (2.9;14.7), p < 0.05)/participation: + 10.5 (6.3;14.7), p < 0.05)). Similar results were found regarding parent-reported fatigue: + 8.7 (3.4;13.9), p < 0.05 but not regarding participation. Two years later, fatigue was still considerable(patients:59.1/parents:62.5). Moderate/fair correlations between fatigue/participation over time were found. Fatigue and participation in young patients with ABI improved two years after referral to rehabilitation. However, fatigue remained a considerable problem

    Parent-reported family impact in children and young adults with acquired brain injury in the outpatient rehabilitation setting

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    Purpose: To increase knowledge/awareness on family impact (FI) after acquired brain injury (ABI) in rehabilitation settings, it is essential to investigate the associations between patient-functioning and impact on families. This has been explored in hospital-based cohorts, but not in rehabilitation settings.Methods: A cross-sectional, multi-center study among parents of children/young adults (aged 57-6 months after onset, diminished patients' mental/emotional health and HRQoL (child/family factors), and premorbid problems were associated with higher FI.Conclusions: In this rehabilitation cohort, pediatric ABI caused considerably higher FI than in hospital-based studies with referral to rehabilitation >6 months, diminished child/family factors and presence of premorbid problems increasing FI. Assessing and monitoring FI and its associated factors enables professionals to individualize treatment, psychoeducation, support and follow-up.Orthopaedics, Trauma Surgery and Rehabilitatio

    Participation restrictions among children and young adults with acquired brain injury in a pediatric outpatient rehabilitation cohort: the patients' and parents' perspective

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    Improving participation is an important aim in outpatient rehabilitation treatment. Knowledge regarding participation restrictions in children and young adults with acquired brain injury (ABI) is scarce and little is known regarding the differences in perspectives between patients and parents in the outpatient rehabilitation setting. The aims are to describe participation restrictions among children/young adults (5-24 years) with ABI and investigating differences between patients' and parents' perspectives. At admission in 10 rehabilitation centers, patients and parents were asked to complete the Child and Adolescent Scale of Participation (CASP; score 0-100; lower score = more restrictions) and injury/patient/family-related questions. CASP scores were categorized (full/somewhat-limited/limited/very-limited participation). Patient/parent-reported outcomes were compared using the Wilcoxon signed-rank test. 223 patients and 245 parents participated (209 paired-samples). Median patients' age was 14 years (IQR; 11-16), 135 were female (52%), 195 had traumatic brain injury (75%). The median CASP score reported by patients was 82.5 (IQR: 67.5-90) and by parents 91.3 (IQR: 80.0-97.5) (difference = p < 0.05). The score of 58 patients (26%) and 25 parents (10%) was classified as 'very-limited'. Twenty-six percent of children and young adults referred for rehabilitation after ABI had "very-limited" participation. Overall, parents rated their child's participation better than patients themselves. Quantifying participation restrictions after ABI and considering both perspectives is important for outpatient rehabilitation treatment.Orthopaedics, Trauma Surgery and Rehabilitatio

    Microglial activation in Alzheimer's disease: an (R)-[11C]PK11195 positron emission tomography study

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    AbstractInflammatory mechanisms, like microglial activation, could be involved in the pathogenesis of Alzheimer's disease (AD). (R)-[11C]PK11195 (1-(2-chlorophenyl)-N-methyl-N-1(1-methylpropyl)-3-isoquinolinecarboxamide), a positron emission tomography (PET) ligand, can be used to quantify microglial activation in vivo. The purpose of this study was to assess whether increased (R)-[11C]PK11195 binding is present in AD and mild cognitive impairment (MCI), currently also known as “prodromal AD.”MethodsNineteen patients with probable AD, 10 patients with prodromal AD (MCI), and 21 healthy control subjects were analyzed. Parametric images of binding potential (BPND) of (R)-[11C]PK11195 scans were generated using receptor parametric mapping (RPM) with supervised cluster analysis. Differences between subject groups were tested using mixed model analysis, and associations between BPND and cognition were evaluated using Pearson correlation coefficients.ResultsVoxel-wise statistical parametric mapping (SPM) analysis showed small clusters of significantly increased (R)-[11C]PK11195 BPND in occipital lobe in AD dementia patients compared with healthy control subjects. Regions of interest (ROI)-based analyses showed no differences, with large overlap between groups. There were no differences in (R)-[11C]PK11195 BPND between clinically stable prodromal AD patients and those who progressed to dementia, and BPND did not correlate with cognitive function.ConclusionMicroglial activation is a subtle phenomenon occurring in AD

    Discovery of early-stage biomarkers for diabetic kidney disease using ms-based metabolomics (FinnDiane study)

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    Diabetic kidney disease (DKD) is a devastating complication that affects an estimated third of patients with type 1 diabetes mellitus (DM). There is no cure once the disease is diagnosed, but early treatment at a sub-clinical stage can prevent or at least halt the progression. DKD is clinically diagnosed as abnormally high urinary albumin excretion rate (AER). We hypothesize that subtle changes in the urine metabolome precede the clinically significant rise in AER. To test this, 52 type 1 diabetic patients were recruited by the FinnDiane study that had normal AER (normoalbuminuric). After an average of 5.5 years of follow-up half of the subjects (26) progressed from normal AER to microalbuminuria or DKD (macroalbuminuria), the other half remained normoalbuminuric. The objective of this study is to discover urinary biomarkers that differentiate the progressive form of albuminuria from non-progressive form of albuminuria in humans. Metabolite profiles of baseline 24 h urine samples were obtained by gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS) to detect potential early indicators of pathological changes. Multivariate logistic regression modeling of the metabolomics data resulted in a profile of metabolites that separated those patients that progressed from normoalbuminuric AER to microalbuminuric AER from those patients that maintained normoalbuminuric AER with an accuracy of 75% and a precision of 73%. As this data and samples are from an actual patient population and as such, gathered within a less controlled environment it is striking to see that within this profile a number of metabolites (identified as early indicators) have been associated with DKD already in literature, but also that new candidate biomarkers were found. The discriminating metabolites included acyl-carnitines, acyl-glycines and metabolites related to tryptophan metabolism. We found candidate biomarkers that were univariately significant different. This study demonstrates the potential of multivariate data analysis and metabolomics in the field of diabetic complications, and suggests several metabolic pathways relevant for further biological studies

    A common and functional mineralocorticoid receptor haplotype enhances optimism and protects against depression in females

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    Mineralocorticoid (MR) and glucocorticoid receptors (GR) are abundantly expressed in the limbic brain and mediate cortisol effects on the stress-response and behavioral adaptation. Dysregulation of the stress response impairs adaptation and is a risk factor for depression, which is twice as abundant in women than in men. Because of the importance of MR for appraisal processes underlying the initial phase of the stress response we investigated whether specific MR haplotypes were associated with personality traits that predict the risk of depression. We discovered a common gene variant (haplotype 2, frequency ∼0.38) resulting in enhanced MR activity. Haplotype 2 was associated with heightened dispositional optimism in study 1 and with less hopelessness and rumination in study 2. Using data from a large genome-wide association study we then established that haplotype 2 was associated with a lower risk of depression. Interestingly, all effects were restricted to women. We propose that common functional MR haplotypes are important determinants of inter-individual variability in resilience to depression in women by differentially mediating cortisol effects on the stress system
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