17 research outputs found

    Loss-of-function variants in DNM1 cause a specific form of developmental and epileptic encephalopathy only in biallelic state

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    BACKGROUND: Developmental and epileptic encephalopathies (DEEs) represent a group of severe neurological disorders characterised by an onset of refractory seizures during infancy or early childhood accompanied by psychomotor developmental delay or regression. DEEs are genetically heterogeneous with, to date, more than 80 different genetic subtypes including DEE31 caused by heterozygous missense variants in DNM1. METHODS: We performed a detailed clinical characterisation of two unrelated patients with DEE and used whole-exome sequencing to identify causative variants in these individuals. The identified variants were tested for cosegregation in the respective families. RESULTS: We excluded pathogenic variants in known, DEE-associated genes. We identified homozygous nonsense variants, c.97C>T; p.(Gln33*) in family 1 and c.850C>T; p.(Gln284*) in family 2, in the DNM1 gene, indicating that biallelic, loss-of-function pathogenic variants in DNM1 cause DEE. CONCLUSION: Our finding that homozygous, loss-of-function variants in DNM1 cause DEE expands the spectrum of pathogenic variants in DNM1. All parents who were heterozygous carriers of the identified loss-of-function variants were healthy and did not show any clinical symptoms, indicating that the type of mutation in DNM1 determines the pattern of inheritance

    USP27X variants underlying X-linked intellectual disability disrupt protein function via distinct mechanisms

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    Neurodevelopmental disorders with intellectual disability (ND/ID) are a heterogeneous group of diseases driving lifelong deficits in cognition and behavior with no definitive cure. X-linked intellectual disability disorder 105 (XLID105, #300984; OMIM) is a ND/ID driven by hemizygous variants in the USP27X gene encoding a protein deubiquitylase with a role in cell proliferation and neural development. Currently, only four genetically diagnosed individuals from two unrelated families have been described with limited clinical data. Furthermore, the mechanisms underlying the disorder are unknown. Here, we report 10 new XLID105 individuals from nine families and determine the impact of gene variants on USP27X protein function. Using a combination of clinical genetics, bioinformatics, biochemical, and cell biology approaches, we determined that XLID105 variants alter USP27X protein biology via distinct mechanisms including changes in developmentally relevant protein-protein interactions and deubiquitylating activity. Our data better define the phenotypic spectrum of XLID105 and suggest that XLID105 is driven by USP27X functional disruption. Understanding the pathogenic mechanisms of XLID105 variants will provide molecular insight into USP27X biology and may create the potential for therapy development.</p

    A Review on the Cosmeceutical and External Applications of Nigella sativa

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    It is estimated by the World Health Organization (WHO) that most of the world’s population depends on herbal medicine for their health care. Nigella sativa (N. sativa), also known as black-caraway and as “Kalonji,” is a well-known seed all over the world. It is one of the most common medicinal plants worldwide and contains many useful chemical constituents that we can find in its fixed oil, such as thymoquinone, thymohydroquinone, dithymoquinone, thymol, nigellicine, carvacrol, nigellimine, nigellicine, nigellidine, and alpha-hederin. Due to these numerous important ingredients it was found that it affects different areas of our body and has many pharmacological effects as antibacterial, antiviral, anti-inflammatory, and wound healing effect and also for acne vulgaris, skin cancer, pigmentation, and many cosmeceutical applications. Based on the folklore usage of N. sativa seeds and oil, they are used in various systems of food and medicines. The aim of this article is to provide a detailed survey of the literature of cosmeceutical and external applications of N. sativa which is expected to stimulate further studies on this subject

    A Review on the Cosmeceutical and External Applications of Nigella sativa

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    It is estimated by the World Health Organization (WHO) that most of the world’s population depends on herbal medicine for their health care. Nigella sativa (N. sativa), also known as black-caraway and as “Kalonji,” is a well-known seed all over the world. It is one of the most common medicinal plants worldwide and contains many useful chemical constituents that we can find in its fixed oil, such as thymoquinone, thymohydroquinone, dithymoquinone, thymol, nigellicine, carvacrol, nigellimine, nigellicine, nigellidine, and alpha-hederin. Due to these numerous important ingredients it was found that it affects different areas of our body and has many pharmacological effects as antibacterial, antiviral, anti-inflammatory, and wound healing effect and also for acne vulgaris, skin cancer, pigmentation, and many cosmeceutical applications. Based on the folklore usage of N. sativa seeds and oil, they are used in various systems of food and medicines. The aim of this article is to provide a detailed survey of the literature of cosmeceutical and external applications of N. sativa which is expected to stimulate further studies on this subject

    Infantile neurodegenerative disorder associated with mutations in TBCD, an essential gene in the tubulin heterodimer assembly pathway

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    © The Author 2016. Published by Oxford University Press. Mutation in a growing spectrum of genes is known to either cause or contribute to primary or secondary microcephaly. In primary microcephaly the genetic determinants frequently involve mutations that contribute to or modulate the microtubule cytoskeleton by causing perturbations of neuronal proliferation and migration. Here we describe four patients from two unrelated families each with an infantile neurodegenerative disorder characterized by loss of developmental milestones at 9-24 months of age followed by seizures, dystonia and acquired microcephaly. The patients harboured homozygous missense mutations (A475T and A586V) in TBCD, a gene encoding one of five tubulin-specific chaperones (termed TBCA-E) that function in concert as a nanomachine required for the de novo assembly of the a/b tubulin heterodimer. The latter is the subunit from which microtubule polymers are assembled. We found a reduced intracellular abundance of TBCD in patient fibroblasts to about 10% (in the case of A475T) or 40% (in the case of A586V) compared to age-matched wild type controls. Functional analyses of the mutant proteins revealed a partially compromised ability to participate in the heterodimer assembly pathway. We show via in utero shRNA-mediated suppression that a balanced supply of tbcd is critical for cortical cell proliferation and radial migration in the developing mouse brain. We conclude that TBCD is a novel functional contributor to the mammalian cerebral cortex development, and that the pathological mechanism resulting from the mutations we describe is likely to involve compromised interactions with one or more TBCD-interacting effectors that influence the dynamics and behaviour of the neuronal cytoskeleton

    SLC4A10 mutation causes a neurological disorder associated with impaired GABAergic transmission

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    SLC4A10 is a plasma-membrane bound transporter which utilizes the Na+ gradient to drive cellular HCO3- uptake, thus mediating acid extrusion. In the mammalian brain, SLC4A10 is expressed in principal neurons and interneurons, as well as in epithelial cells of the choroid plexus, the organ regulating the production of cerebrospinal fluid. Using next generation sequencing on samples from five unrelated families encompassing ten affected individuals, we show that biallelic SLC4A10 loss-of-function variants cause a clinically recognizable neurodevelopmental disorder in humans. The cardinal clinical features of the condition include hypotonia in infancy, delayed psychomotor development across all domains and typically severe intellectual impairment. Affected individuals commonly display traits associated with autistic spectrum disorders including anxiety, hyperactivity and stereotyped movements. In two cases isolated episodes of seizures were reported in the first few years of life, and a further affected child displayed bitemporal epileptogenic discharges on EEG without overt clinical seizures. While occipitofrontal circumference was reported to be normal at birth, progressive postnatal microcephaly evolved in 7 out of 10 affected individuals. Neuroradiological features included a relative preservation of brain volume compared to occipitofrontal circumference, characteristic narrow sometimes 'slit-like' lateral ventricles and corpus callosum abnormalities. Slc4a10 -/- mice, deficient for SLC4A10, also display small lateral brain ventricles and mild behavioral abnormalities including delayed habituation and alterations in the 2-object novel object recognition task. Collapsed brain ventricles in both Slc4a10-/- mice and affected individuals suggests an important role of SLC4A10 in the production of the cerebrospinal fluid. However, it is notable that despite diverse roles of the cerebrospinal fluid in the developing and adult brain, the cortex of Slc4a10-/- mice appears grossly intact. Co-staining with synaptic markers revealed that in neurons, SLC4A10 localizes to inhibitory, but not excitatory, presynapses. These findings are supported by our functional studies which show the release of the inhibitory neurotransmitter GABA is compromised in Slc4a10-/- mice, while the release of the excitatory neurotransmitter glutamate is preserved. Manipulation of intracellular pH partially rescues GABA release. Together our studies define a novel characteristic neurodevelopmental disorder associated with biallelic pathogenic variants in SLC4A10 and highlight the importance of further analyses of the consequences of SLC4A10 loss-of-function for brain development, synaptic transmission and network properties.Published version, accepted version (12 month embargo), submitted versionThe article is available via Open Access. Click on the 'Additional link' above to access the full-text

    TryCYCLE: A Prospective Study of the Safety and Feasibility of Early In-Bed Cycling in Mechanically Ventilated Patients

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    <div><p>Introduction</p><p>The objective of this study was to assess the safety and feasibility of in-bed cycling started within the first 4 days of mechanical ventilation (MV) to inform a future randomized clinical trial.</p><p>Methods</p><p>We conducted a 33-patient prospective cohort study in a 21-bed adult academic medical-surgical intensive care unit (ICU) in Hamilton, ON, Canada. We included adult patients (≥ 18 years) receiving MV who walked independently pre-ICU. Our intervention was 30 minutes of in-bed supine cycling 6 days/week in the ICU. Our primary outcome was Safety (termination), measured as events prompting cycling termination; secondary Safety (disconnection or dislodgement) outcomes included catheter/tube dislodgements. Feasibility was measured as consent rate and fidelity to intervention. For our primary outcome, we calculated the binary proportion and 95% confidence interval (CI).</p><p>Results</p><p>From 10/2013-8/2014, we obtained consent from 34 of 37 patients approached (91.9%), 33 of whom received in-bed cycling. Of those who cycled, 16(48.4%) were female, the mean (SD) age was 65.8(12.2) years, and APACHE II score was 24.3(6.7); 29(87.9%) had medical admitting diagnoses. Cycling termination was infrequent (2.0%, 95% CI: 0.8%-4.9%) and no device dislodgements occurred. Cycling began a median [IQR] of 3 [2, 4] days after ICU admission; patients received 5 [3, 8] cycling sessions with a median duration of 30.7 [21.6, 30.8] minutes per session. During 205 total cycling sessions, patients were receiving invasive MV (150 [73.1%]), vasopressors (6 [2.9%]), sedative or analgesic infusions (77 [37.6%]) and dialysis (4 [2.0%]).</p><p>Conclusions</p><p>Early cycling within the first 4 days of MV among hemodynamically stable patients is safe and feasible. Research to evaluate the effect of early cycling on patient function is warranted.</p><p>Trial Registration</p><p>Clinicaltrials.gov: <a href="https://clinicaltrials.gov/ct2/show/NCT01885442" target="_blank">NCT01885442</a></p></div
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