620 research outputs found
Genetics of Type A Behavior in Two European Countries: Evidence for Sibling Interaction
Young male twins in The Netherlands and England completed the Jenkins Activity Survey (Dutch and English versions, respectively), a measure of Type A behavior. Separate model fitting analysis revealed a similar pattern of variance estimates and associated goodness of fit across the two countries. The data were then analyzed concurrently, with a scalar parameter included to account for differences in variance due to the disparity of the measurement scales. A model including additive genetic and individual environmental effects gave a good explanation to the data. The heritability estimate was 0.28. Models of social interaction and dominance explained the data even better, the former being preferred. The twins' parents were included in the analysis to examine population variation for Type A behavior intergenerationally. There was evidence for individual environmental experiences having a greater influence on Type A behavior in the older generation. © 1991 Plenum Publishing Corporation
Quantification and confocal imaging of protein specific molecularly imprinted polymers
We have employed FITC-albumin as the protein template molecule in an aqueous phase molecular imprinted polymer (HydroMIP) strategy. For the first time, the use of a fluorescently labelled template is reported, with subsequent characterisation of the smart material to show that the HydroMIP possess a significant molecular memory in comparison to that of the nonimprinted control polymer (HydroNIP). The imaging of the FITC-albumin imprinted HydroMIP using confocal microscopy is described, with the in situ removal of imprinted protein displayed in terms of observed changes in the fluorescence of the imprinted polymer, both before and after template elution (using a 10% SDS/10% AcOH (w/v) solution). We also report the imaging of a bovine haemoglobin (BHb) imprinted HydroMIP using two-photon confocal microscopy, and describe the effects of template elution upon protein autofluorescence. The findings further contribute to the understanding of aqueous phase molecular imprinting protocols, and document the use of fluorescence as a useful tool in template labelling/detection and novel imaging strategies
Restoring brain function after stroke - bridging the gap between animals and humans
Stroke is the leading cause of complex adult disability in the world. Recovery from stroke is often incomplete, which leaves many people dependent on others for their care. The improvement of long-term outcomes should, therefore, be a clinical and research priority. As a result of advances in our understanding of the biological mechanisms involved in recovery and repair after stroke, therapeutic opportunities to promote recovery through manipulation of poststroke plasticity have never been greater. This work has almost exclusively been carried out in preclinical animal models of stroke with little translation into human studies. The challenge ahead is to develop a mechanistic understanding of recovery from stroke in humans. Advances in neuroimaging techniques now enable us to reconcile behavioural accounts of recovery with molecular and cellular changes. Consequently, clinical trials can be designed in a stratified manner that takes into account when an intervention should be delivered and who is most likely to benefit. This approach is expected to lead to a substantial change in how restorative therapeutic strategies are delivered in patients after stroke
Genetic correlation between amyotrophic lateral sclerosis and schizophrenia
We have previously shown higher-than-expected rates of schizophrenia in relatives of patients with amyotrophic lateral sclerosis (ALS), suggesting an aetiological relationship between the diseases. Here, we investigate the genetic relationship between ALS and schizophrenia using genome-wide association study data from over 100,000 unique individuals. Using linkage disequilibrium score regression, we estimate the genetic correlation between ALS and schizophrenia to be 14.3% (7.05-21.6; P=1 × 10-4) with schizophrenia polygenic risk scores explaining up to 0.12% of the variance in ALS (P=8.4 × 10-7). A modest increase in comorbidity of ALS and schizophrenia is expected given these findings (odds ratio 1.08-1.26) but this would require very large studies to observe epidemiologically. We identify five potential novel ALS-associated loci using conditional false discovery rate analysis. It is likely that shared neurobiological mechanisms between these two disorders will engender novel hypotheses in future preclinical and clinical studies
MALT1 Phosphorylation Controls Activation of T Lymphocytes and Survival of ABC-DLBCL Tumor Cells
The CARMA1/CARD11-BCL10-MALT1 (CBM) complex bridges T and B cell antigen receptor (TCR/BCR) ligation to MALT1 protease activation and canonical nuclear factor kappa B (NF-kappa B) signaling. Using unbiased mass spectrometry, we discover multiple serine phosphorylation sites in the MALT1 C terminus after T cell activation. Phospho-specific antibodies reveal that CBM-associated MALT1 is transiently hyper-phosphorylated upon TCR/CD28 co-stimulation. We identify a dual role for CK1 alpha as a kinase that is essential for CBM signalosome assembly as well as MALT1 phosphorylation. Although MALT1 phosphorylation is largely dispensable for protease activity, it fosters canonical NF-kappa B signaling in Jurkat and murine CD4 T cells. Moreover, constitutive MALT1 phosphorylation promotes survival of activated B cell-type diffuse large B cell lymphoma (ABC-DLBCL) cells addicted to chronic BCR signaling. Thus, MALT1 phosphorylation triggers optimal NF-kappa B activation in lymphocytes and survival of lymphoma cells
Switching behaviour in vascular smooth muscle cell–matrix adhesion during oscillatory loading
Integrins regulate mechanotransduction between smooth muscle cells (SMCs) and the extracellular matrix (ECM). SMCs resident in the walls of airways or blood vessels are continuously exposed to dynamic mechanical forces due to breathing or pulsatile blood flow. However, the resulting effects of these forces on integrin dynamics and associated cell-matrix adhesion are not well understood. Here we present experimental results from atomic force microscopy (AFM) experiments, designed to study the integrin response to external oscillatory loading of varying amplitudes applied to live aortic SMCs, together with theoretical results from a mathematical model. In the AFM experiments, a fibronectin-coated probe was used cyclically to indent and retract from the surface of the cell. We observed a transition between states of firm adhesion and of complete detachment as the amplitude of oscillatory loading increased, revealed by qualitative changes in the force timecourses. Interestingly, for some of the SMCs in the experiments, switching behaviour between the two adhesion states is observed during single timecourses at intermediate amplitudes. We obtain two qualitatively similar adhesion states in the mathematical model, where we simulate the cell, integrins and ECM as an evolving system of springs, incorporating local integrin binding dynamics. In the mathematical model, we observe a region of bistability where both the firm adhesion and detachment states can occur depending on the initial adhesion state. The differences are seen to be a result of mechanical cooperativity of integrins and cell deformation. Switching behaviour is a phenomenon associated with bistability in a stochastic system, and bistability in our deter-ministic mathematical model provides a potential physical explanation for the experimental results. Physiologically, bistability provides a means for transient mechanical stimuli to induce long-term changes in adhesion dynamics-and thereby the cells' ability to transmit force-and we propose further experiments for testing this hypothesis
Factors influencing longitudinal changes of circulating liver enzyme concentrations in subjects randomized to placebo in four clinical trials
Liver enzyme concentrations are measured as safety end points in clinical trials to detect drug-related hepatotoxicity, but little is known about the epidemiology of these biomarkers in subjects without hepatic dysfunction who are enrolled in drug trials. We studied alanine and aspartate aminotransferase (ALT and AST) in subjects randomized to placebo who completed assessments over 36 mo in a cardiovascular outcome trial [the Stabilisation of Atherosclerotic Plaque by Initiation of Darapladib Therapy ("STABILITY") trial; n = 4,264; mean age: 64.2 yr] or over 12 mo in three trials that enrolled only subjects with type 2 diabetes (T2D) [the DIA trials; n = 308; mean age: 62.4 yr] to investigate time-dependent relationships and the factors that might affect ALT and AST, including body mass index (BMI), T2D, and renal function. Multivariate linear mixed models examined time-dependent relationships between liver enzyme concentrations as response variables and BMI, baseline T2D status, hemoglobin A1clevels, and renal function, as explanatory variables. At baseline, ALT was higher in individuals who were men, 60 ml·min−1·1.73 m−2. ALT was not significantly associated with T2D at baseline, although it was positively associated with HbA1c. GFR had a greater impact on ALT than T2D. ALT concentrations decreased over time in subjects who lost weight but remained stable in individuals with increasing BMI. Weight change did not alter AST concentrations. We provide new insights on the influence of time, GFR, and HbA1con ALT and AST concentrations and confirm the effect of sex, age, T2D, BMI, and BMI change in subjects receiving placebo in clinical trials.NEW & NOTEWORTHY Clinical trials provide high-quality data on liver enzyme concentrations from subjects randomized to placebo that can be used to investigate the epidemiology of these biomarkers. The adjusted models show the influence of sex, age, time, renal function, type 2 diabetes, HbA1c, and body mass index on alanine aminotransferase and aspartate aminotransferase concentrations and their relative importance. These factors need to be considered when assessing potential signals of hepatotoxicity in trials of new drugs and in clinical trials investigating subjects with nonalcoholic fatty liver disease
Author Correction: A ferroptosis–based panel of prognostic biomarkers for Amyotrophic Lateral Sclerosis
Correction to: Scientific Reports https://doi.org/10.1038/s41598-019-39739-5, published online 27 February 201
The Amyotrophic Lateral Sclerosis M114T PFN1 Mutation Deregulates Alternative Autophagy Pathways and Mitochondrial Homeostasis
International audienceMutations in profilin 1 (PFN1) have been identified in rare familial cases of Amyotrophic Lateral Sclerosis (ALS). PFN1 is involved in multiple pathways that could intervene in ALS pathology. However, the specific pathogenic role of PFN1 mutations in ALS is still not fully understood. We hypothesized that PFN1 could play a role in regulating autophagy pathways and that PFN1 mutations could disrupt this function. We used patient cells (lymphoblasts) or tissue (post-mortem) carrying PFN1 mutations (M114T and E117G), and designed experimental models expressing wild-type or mutant PFN1 (cell lines and novel PFN1 mice established by lentiviral transgenesis) to study the effects of PFN1 mutations on autophagic pathway markers. We observed no accumulation of PFN1 in the spinal cord of one E117G mutation carrier. Moreover, in patient lymphoblasts and transfected cell lines, the M114T mutant PFN1 protein was unstable and deregulated the RAB9-mediated alternative autophagy pathway involved in the clearance of damaged mitochondria. In vivo, motor neurons expressing M114T mutant PFN1 showed mitochondrial abnormalities. Our results demonstrate that the M114T PFN1 mutation is more deleterious than the E117G variant in patient cells and experimental models and suggest a role for the RAB9-dependent autophagic pathway in ALS
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