67 research outputs found
Phenotypic spectrum of MFN2 mutations in the Spanish population
INTRODUCTION: The most common form of axonal Charcot-Marie-Tooth (CMT) disease is type 2A, caused by mutations in the mitochondrial GTPase mitofusin 2 (MFN2). OBJECTIVE: The objective of our study is to establish the incidence of MFN2 mutations in a cohort of Spanish patients with axonal CMT neuropathy. MATERIAL AND METHODS: Eighty-five families with suspected axonal CMT were studied. All MFN2 exons were studied through direct sequencing. A bioenergetics study in fibroblasts was conducted using a skin biopsy taken from a patient with an Arg468His mutation. RESULTS: Twenty-four patients from 14 different families were identified with nine different MFN2 mutations (Arg94Trp, Arg94Gln, Ile203Met, Asn252Lys, Gln276His, Gly296Arg, Met376Val, Arg364Gln and Arg468His). All mutations were found in the heterozygous state and four of these mutations had not been described previously. MFN2 mutations were responsible for CMT2 in 16% +/- 7% of the families studied and in 30.8 +/- 14.2% (12/39) of families with known dominant inheritance. The bioenergetic studies in fibroblasts show typical results of MFN2 patients with a mitochondrial coupling defect (ATP/O) and an increase of the respiration rate linked to complex II. CONCLUSION: It is concluded that mutations in MFN2 are the most frequent cause of CMT2 in this region. The Arg468His mutation was the most prevalent (6/14 families), and our study confirms that it is pathological, presenting as a neuropathy in a mild to moderate degree. This study also demonstrates the value of MFN2 studies in cases of congenital axonal neuropathy, especially in cases of dominant inheritance, severe clinical symptoms or additional symptoms such as optic atrophy
MLIP genotype as a predictor of pharmacological response in primary open-angle glaucoma and ocular hypertension.
Predicting the therapeutic response to ocular hypotensive drugs is crucial for the clinical treatment and management of glaucoma. Our aim was to identify a possible genetic contribution to the response to current pharmacological treatments of choice in a white Mediterranean population with primary open-angle glaucoma (POAG) or ocular hypertension (OH). We conducted a prospective, controlled, randomized, partial crossover study that included 151 patients of both genders, aged 18 years and older, diagnosed with and requiring pharmacological treatment for POAG or OH in one or both eyes. We sought to identify copy number variants (CNVs) associated with differences in pharmacological response, using a DNA pooling strategy of carefully phenotyped treatment responders and non-responders, treated for a minimum of 6 weeks with a beta-blocker (timolol maleate) and/or prostaglandin analog (latanoprost). Diurnal intraocular pressure reduction and comparative genome wide CNVs were analyzed. Our finding that copy number alleles of an intronic portion of the MLIP gene is a predictor of pharmacological response to beta blockers and prostaglandin analogs could be used as a biomarker to guide first-tier POAG and OH treatment. Our finding improves understanding of the genetic factors modulating pharmacological response in POAG and OH, and represents an important contribution to the establishment of a personalized approach to the treatment of glaucoma
Quantitative Analysis of Bloggers Collective Behavior Powered by Emotions
Large-scale data resulting from users online interactions provide the
ultimate source of information to study emergent social phenomena on the Web.
From individual actions of users to observable collective behaviors, different
mechanisms involving emotions expressed in the posted text play a role. Here we
combine approaches of statistical physics with machine-learning methods of text
analysis to study emergence of the emotional behavior among Web users. Mapping
the high-resolution data from digg.com onto bipartite network of users and
their comments onto posted stories, we identify user communities centered
around certain popular posts and determine emotional contents of the related
comments by the emotion-classifier developed for this type of texts. Applied
over different time periods, this framework reveals strong correlations between
the excess of negative emotions and the evolution of communities. We observe
avalanches of emotional comments exhibiting significant self-organized critical
behavior and temporal correlations. To explore robustness of these critical
states, we design a network automaton model on realistic network connections
and several control parameters, which can be inferred from the dataset.
Dissemination of emotions by a small fraction of very active users appears to
critically tune the collective states
Simultaneous MFN2 and GDAP1 mutations cause major mitochondrial defects in a patient with CMT
International audienc
MFN2 point mutations occur in 3.4% of Charcot-Marie-Tooth families. An investigation of 232 Norwegian CMT families
Background
Point mutations in the mitofusin 2 (MFN2) gene has been identified exclusively in Charcot-Marie-Tooth type 2 (CMT2), and in a single family with intermediate CMT. MFN2 point mutations are probably the most common cause of CMT2.
Methods
Two-hundred and thirty-two consecutive unselected and unrelated CMT families with available DNA from all regions in Norway were included. We screened for point mutations in the MFN2 gene.
Results
We identified four known and three novel point mutations in 8 unrelated CMT families. The novel point mutations were not found in 100 healthy controls. This corresponds to 3.4% (8/232) of CMT families have point mutations in the MFN2 gene. The phenotypes were compatible with CMT1 in two families, CMT2 in four families, intermediate CMT in one family and distal Hereditary Motor Neuropathy (dHMN) in one family. This corresponds to 2.3% of CMT1, 5.5% of CMT2, 12.5% of intermediate CMT and 6.7% of dHMN families have a point mutation in the MFN2 gene. Point mutations in the MFN2 gene is likely to be the fourth most common cause to CMT after duplication of the peripheral myelin protein 22 (PMP22) gene, and point mutations in the Connexin32 (Cx32) and myelin protein zero (MPZ) genes.
Conclusions
The identified known and novel point mutations in the MFN2 gene expand the clinical spectrum from CMT2 and intermediate CMT to also include possibly CMT1 and the dHMN phenotypes. Thus, genetic analyses of the MFN2 gene should not be restricted to persons with CMT2
Mutation in the Gene Encoding Ubiquitin Ligase LRSAM1 in Patients with Charcot-Marie-Tooth Disease
Charcot-Marie-Tooth disease (CMT) represents a family of related sensorimotor neuropathies. We studied a large family from a rural eastern Canadian community, with multiple individuals suffering from a condition clinically most similar to autosomal recessive axonal CMT, or AR-CMT2. Homozygosity mapping with high-density SNP genotyping of six affected individuals from the family excluded 23 known genes for various subtypes of CMT and instead identified a single homozygous region on chromosome 9, at 122,423,730–129,841,977 Mbp, shared identical by state in all six affected individuals. A homozygous pathogenic variant was identified in the gene encoding leucine rich repeat and sterile alpha motif 1 (LRSAM1) by direct DNA sequencing of genes within the region in affected DNA samples. The single nucleotide change mutates an intronic consensus acceptor splicing site from AG to AA. Direct analysis of RNA from patient blood demonstrated aberrant splicing of the affected exon, causing an obligatory frameshift and premature truncation of the protein. Western blotting of immortalized cells from a homozygous patient showed complete absence of detectable protein, consistent with the splice site defect. LRSAM1 plays a role in membrane vesicle fusion during viral maturation and for proper adhesion of neuronal cells in culture. Other ubiquitin ligases play documented roles in neurodegenerative diseases. LRSAM1 is a strong candidate for the causal gene for the genetic disorder in our kindred
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Longitudinal Changes in Multiple Biomarkers Are Associated with Cardiotoxicity in Breast Cancer Patients Treated with Doxorubicin, Taxanes, and Trastuzumab
BACKGROUND: Biomarkers may play an important role in identifying patients at risk for cancer therapy cardiotoxicity. Our objectives were to define the patterns of change in biomarkers with cancer therapy and their associations with cardiotoxicity. METHODS: In a multicenter cohort of 78 breast cancer patients undergoing doxorubicin and trastuzumab therapy, 8 biomarkers were evaluated at baseline and every 3 months over a maximum follow-up of 15 months. These biomarkers, hypothesized to be mechanistically relevant to cardiotoxicity, included high-sensitivity cardiac troponin I (hs-cTnI), high-sensitivity C-reactive protein (hsCRP), N-terminal pro–B-type natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), myeloperoxidase (MPO), placental growth factor (PlGF), soluble fms-like tyrosine kinase receptor-1 (sFlt-1), and galectin 3 (gal-3). We determined if biomarker increases were associated with cardiotoxicity at the same visit and the subsequent visit over the entire course of therapy. Cardiotoxicity was defined by the Cardiac Review and Evaluation Criteria; alternative definitions were also considered. RESULTS: Across the entire cohort, all biomarkers except NT-proBNP and gal-3 demonstrated increases by 3 months; these increases persisted for GDF-15, PlGF, and hs-cTnI at 15 months. Increases in MPO, PlGF, and GDF-15 were associated with cardiotoxicity at the same visit [MPO hazard ratio 1.38 (95% CI 1.10–1.71), P = 0.02; PlGF 3.78 (1.30–11.0), P = 0.047; GDF-15 1.71 (1.15–2.55), P = 0.01] and the subsequent visit. MPO was robust to alternative outcome definitions. CONCLUSIONS: Increases in MPO are associated with cardiotoxicity over the entire course of doxorubicin and trastuzumab therapy. Assessment with PlGF and GDF-15 may also be of value. These findings motivate validation studies in additional cohorts
Don't erase
Aquesta exposició del Postgrau en Il·lustració creativa i tècniques de comunicació visual d’EINA és una mostra condensada de l’odissea personal que 26 il·lustradors hem fet durant un any. Us ensenyem fins a on hem arribat sota la consigna de “No esborrar”, d’abraçar l’error i perdre-li la por, de trobar la nostra manera única i intransferible d’il·lustrar. No hi ha camí ràpid per convertir-se en il·lustrador o il·lustradora d’èxit, igualment no hi ha una única manera d’il·lustrar. Cadascun de nosaltres ho fem i ho seguirem fent a la nostra manera, però el que està clar és que per il·lustrar bé necessites fer-ho sense por, amb confiança i seguretat en els encerts i també en els errors perquè això és el que fa que una obra ens emocioni.Esta exposición del Postgrado en Ilustración creativa y técnicas de comunicación visual de EINA es una muestra condensada de la odisea personal que 26 ilustradores hemos hecho durante un año. Os enseñamos hasta donde hemos llegado bajo la consigna de “No borrar”, de abrazar el error y perderle el miedo, de encontrar nuestra manera única e intransferible de ilustrar. No existe el camino rápido para convertirse en ilustrador o ilustradora de éxito, al igual que no hay una única forma de ilustrar, cada uno de nosotros lo hace y lo seguirá haciendo a su manera, pero lo que está claro es que para ilustrar bien necesitas hacerlo sin miedo, con confianza y seguridad en tus aciertos y también en tus errores porque eso es lo que hace que una obra nos emocione.This exhibition of the Postgraduate Diploma in Creative Illustration and Visual Communication Techniques of EINA is a condensed sample of the personal odyssey that 26 illustrators have made in the past year. In it we show you, the public, how far we have come under the slogan of “Don’t Erase”, of embracing error and facing our fears, of finding our unique and non-transferable way of illustrating. There is no quick way to become a successful illustrator, just as there is no single way to illustrate, each one of us will continue to work his or her own way, but what is clear is that to illustrate well you need to do it without fear, with confidence in both your achievements and failures because that is what helps create emotional, moving work
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