18 research outputs found

    Mitochondrial fission factor (MFF) frameshift variant in Bullmastiffs with mitochondrial fission encephalopathy.

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    Familial cerebellar ataxia with hydrocephalus in Bullmastiffs was described almost 40 years ago as a monogenic autosomal recessive trait. We investigated two young Bullmastiffs showing similar clinical signs. They developed progressive gait and behavioural abnormalities with an onset at around 6 months of age. Neurological assessment was consistent with a multifocal brain disease. Magnetic resonance imaging of the brain showed intra-axial bilateral symmetrical focal lesions localised to the cerebellar nuclei. Based on the juvenile age, nature of neurological deficits and imaging findings, an inherited disorder of the brain was suspected. We sequenced the genome of one affected Bullmastiff. The data were compared with 782 control genomes of dogs from diverse breeds. This search revealed a private homozygous frameshift variant in the MFF gene in the affected dog, XM_038574000.1:c.471_475delinsCGCTCT, that is predicted to truncate 55% of the wild type MFF open reading frame, XP_038429928.1: p.(Glu158Alafs*14). Human patients with pathogenic MFF variants suffer from 'encephalopathy due to defective mitochondrial and peroxisomal fission 2'. Archived samples from two additional affected Bullmastiffs related to the originally described cases were obtained. Genotypes in a cohort of four affected and 70 unaffected Bullmastiffs showed perfect segregation with the disease phenotype. The available data together with information from previous disease reports allow classification of the investigated MFF frameshift variant as pathogenic and probably causative defect of the observed neurological phenotype. In analogy to the human phenotype, we propose to rename this disease 'mitochondrial fission encephalopathy (MFE)'

    Juvenile-onset polyneuropathy in American Staffordshire Terriers

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    Background: The only hereditary neurologic disorder described so far in American Staffordshire Terriers is adult-onset cerebellar degeneration secondary to ceroid lipofuscinosis. We have seen several dogs with a newly recognized neurological disease characterized by locomotor weakness with or without respiratory signs and juvenile onset consistent with degenerative polyneuropathy of genetic origin. Objectives: To characterize a novel polyneuropathy in juvenile American Staffordshire Terriers. Animals: Fourteen American Staffordshire Terriers presented with clinical signs consistent with juvenile-onset polyneuropathy at 5 veterinary hospitals between May 2005 and July 2017. Methods: Case series. Dogs were included retrospectively after a diagnosis of degenerative polyneuropathy had been confirmed by nerve biopsy. Clinical, pathological, electrophysiological, histological data, and outcome were reviewed and a pedigree analysis performed. Results: All dogs displayed clinical signs of neuromuscular disease with generalized motor and sensory involvement, associated with focal signs of laryngeal paralysis (10/14 dogs) and megaesophagus (1/14 dogs). Histopathological findings were consistent with degenerative polyneuropathy. Follow-up was available for 11 dogs, and 3 dogs were euthanized shortly after diagnosis. In these 11 dogs, the disease was slowly progressive and the animals maintained good quality of life with ability to walk. Pedigree analysis was mostly consistent with an autosomal recessive mode of inheritance. Conclusions and Clinical Importance: Juvenile polyneuropathy, associated with laryngeal paralysis, is a newly described entity in American Staffordshire Terriers, and results from degenerative neuropathy. When surgery for laryngeal paralysis is performed, lifespan may be similar to that of normal dogs even though affected dogs have locomotor disturbance

    Differential effects of Atomoxetine on executive functioning and lexical decision in Attention-Deficit/Hyperactivity Disorder and Reading Disorder

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    Objective: The effects of a promising pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD), atomoxetine, were studied on executive functions in both ADHD and reading disorder (RD) because earlier research demonstrated an overlap in executive functioning deficits in both disorders. In addition, the effects of atomoxetine were explored on lexical decision. Methods: Sixteen children with ADHD, 20 children with ADHD + RD, 21 children with RD, and 26 normal controls were enrolled in a randomized placebo-controlled crossover study. Children were measured on visuospatial working memory, inhibition, and lexical decision on the day of randomization and following two 28-day medication periods. Results: Children with ADHD + RD showed improved visuospatial working memory performance and, to a lesser extent, improved inhibition following atomoxetine treatment compared to placebo. No differential effects of atomoxetine were found for lexical decision in comparison to placebo. In addition, no effects of atomoxetine were demonstrated in the ADHD and RD groups. Conclusion: Atomoxetine improved visuospatial working memory and to a lesser degree inhibition in children with ADHD + RD, which suggests differential developmental pathways for co-morbid ADHD + RD as compared to ADHD and RD alone

    Canine Lafora Disease: An Unstable Repeat Expansion Disorder

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    Canine Lafora disease is a recessively inherited, rapidly progressing neurodegenerative disease caused by the accumulation of abnormally constructed insoluble glycogen Lafora bodies in the brain and other tissues due to the loss of NHL repeat containing E3 ubiquitin protein ligase 1 (NHLRC1). Dogs have a dodecamer repeat sequence within the NHLRC1 gene, which is prone to unstable (dynamic) expansion and loss of function. Progressive signs of Lafora disease include hypnic jerks, reflex and spontaneous myoclonus, seizures, vision loss, ataxia and decreased cognitive function. We studied five dogs (one Chihuahua, two French Bulldogs, one Griffon Bruxellois, one mixed breed) with clinical signs associated with canine Lafora disease. Identification of polyglucosan bodies (Lafora bodies) in myocytes supported diagnosis in the French Bulldogs; muscle areas close to the myotendinous junction and the myofascial union segment had the highest yield of inclusions. Postmortem examination of one of the French Bulldogs revealed brain Lafora bodies. Genetic testing for the known canine NHLRC1 mutation confirmed the presence of a homozygous mutation associated with canine Lafora disease. Our results show that Lafora disease extends beyond previous known breeds to the French Bulldog, Griffon Bruxellois and even mixed-breed dogs, emphasizing the likely species-wide nature of this genetic problem. It also establishes these breeds as animal models for the devastating human disease. Genetic testing should be used when designing breeding strategies to determine the frequency of the NHLRC1 mutation in affected breeds. Lafora diseases should be suspected in any older dog presenting with myoclonus, hypnic jerks or photoconvulsions

    Downregulation of MiR-449a Is Essential for the Survival of EVII Positive Leukemic Cells through Modulation of NOTCH1 and BCL2

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    Chromosomal rearrangements involving the EVI1 gene are a recurrent finding in malignant myeloid disorders. These translocations or inversions contribute to ectopic expression or to the formation of fusion genes involving the EVI1 gene. EVI1 transcriptional activation has been reported in up to 10% of acute myeloid leukemia (AML) and is a prognostic marker of poor outcome. MicroRNA (miRNA) deregulation was recently identified as a major contributor to cancer initiation and progression. As miRNA genes were shown to be directly regulated by activated proto-oncogenes, we aimed to identify miRNAs under direct or indirect control of EVI1. To this purpose, we analyzed the expression of 366 miRNAs in 38 EVI1 rearranged/overexpressing patient samples, 6 normal bone marrow controls and 2 EVI1 knockdown model systems (siRNA mediated EVI1 knockdown in the EVI1 rearranged/overexpressing cell lines Kasumi-3 and UCSD-AML1). In total, 24 upregulated and 25 downregulated miRNAs (p<0.05) were shown to be related to the EVI1 expression status. Amongst these, miR-449a was selected for further study based on its homology to the known cancer associated miRNA miR-34a. Downregulation of miR-449a by EVI1 was further confirmed in the leukemic cell line U937 with tetracycline controllabel (tet-off) EVI1 overexpression. Next, direct transcriptional regulation of miR-449a expression by EVI1 was demonstrated by chromatin immunoprecipitation (ChIP). To test the functional consequences of downregulation of miR-449a in AML cells, reconstitution of the expression of miR-449a in the Kasumi-3 and UCSD-AML1 cell lines was performed, which resulted in significantly decreased cell viability, increased apoptosis and differentiation towards the megakaryocytic and monocytic lineages. Interestingly, siRNA mediated knockdown of EVI1 expression in Kasumi-3 or UCSD-AML1 almost completely abrogated the miR-449a induced reduction in cell viability, while electroporation of both cell lines with EVI1 siRNAs alone had essentially no effect on cell viability. These data strongly suggest that repression of miR-449a expression is essential for the survival and growth of EVI1 overexpressing cells and that this requirement is specifically imposed by EVI1 itself. We next demonstrated that the predicted miR-449a targets NOTCH1 and BCL2 were bona fide miR-449a targets using promoter reporter assays. To asses the contribution of these target genes to the observed phenotype upon miR-449a upregulation, knockdown of NOTCH1 and BCL2 was performed, revealing similar effects on cell viability and apoptosis. These results indicated that the effects seen upon treatment of cells with a precursor miR-449a are at least partly mediated through NOTCH1 and BCL2. In conclusion, we provided for the first time evidence that EVI1 mediated downregulation of miR-449a leads to NOTCH1 and BCL2 upregulation and is required for sustained proliferation and survival of EVI1 overexpressing cells. These data also open new perspectives for therapeutic intervention through modulation of miR-449a and/or its target genes

    Molecular remission is an independent predictor of clinical outcome in patients with mantle cell lymphoma after combined immunochemotherapy: A European MCL intergroup study

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    The prognostic impact of minimal residual disease (MRD) was analyzed in 259 patients with mantle cell lymphoma (MCL) treated within 2 randomized trials of the European MCL Network (MCL Younger and MCL Elderly trial). After rituximab-based induction treatment, 106 of 190 evaluable patients (56%) achieved a molecular remission (MR) based on blood and/or bone marrow (BM) analysis. MR resulted in a significantly improved response duration (RD; 87% vs 61% patients in remission at 2 years, P = .004) and emerged to be an independent prognostic factor for RD (hazard ratio = 0.4, 95% confidence interval, 0.1-0.9, P = .028). MR was highly predictive for prolonged RD independent of clinical response (complete response [CR], complete response unconfirmed [CRu], partial response [PR]; RD at 2 years: 94% in BM MRD-negative CR/CRu and 100% in BM MRD-negative PR, compared with 71% in BM MRD-positive CR/CRu and 51% in BM MRDpositive PR, P = .002). Sustained MR during the postinduction period was predictive for outcome in MCL Younger after autologous stem cell transplantation (ASCT; RD at 2 years 100% vs 65%, P = .001) and during maintenance in MCL Elderly (RD at 2 years: 76% vs 36%, P = .015). ASCT increased the proportion of patients in MR from 55% before high-dose therapy to 72% thereafter. Sequential MRD monitoring is a powerful predictor for treatment outcome in MCL. These trials are registered at www.clinicaltrials.gov as #NCT00209222 and #NCT00209209

    Optimization of adsorptive removal of α-toluic acid by CaO2 nanoparticles using response surface methodology

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    The present work addresses the optimization of process parameters for adsorptive removal of α-toluic acid by calcium peroxide (CaO2) nanoparticles using response surface methodology (RSM). CaO2 nanoparticles were synthesized by chemical precipitation method and confirmed by Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analysis which shows the CaO2 nanoparticles size range of 5–15 nm. A series of batch adsorption experiments were performed using CaO2 nanoparticles to remove α-toluic acid from the aqueous solution. Further, an experimental based central composite design (CCD) was developed to study the interactive effect of CaO2 adsorbent dosage, initial concentration of α-toluic acid, and contact time on α-toluic acid removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was performed to determine the significance of the individual and the interactive effects of variables on the response. The model predicted response showed a good agreement with the experimental response, and the coefficient of determination, (R2) was 0.92. Among the variables, the interactive effect of adsorbent dosage and the initial α-toluic acid concentration was found to have more influence on the response than the contact time. Numerical optimization of process by RSM showed the optimal adsorbent dosage, initial concentration of α-toluic acid, and contact time as 0.03 g, 7.06 g/L, and 34 min respectively. The predicted removal efficiency was 99.50%. The experiments performed under these conditions showed α-toluic acid removal efficiency up to 98.05%, which confirmed the adequacy of the model prediction

    Suicidal ideation in a European Huntington's disease population.

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