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1.
Am J Hum Genet ; 110(8): 1343-1355, 2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37541188

RESUMEN

Despite significant progress in unraveling the genetic causes of neurodevelopmental disorders (NDDs), a substantial proportion of individuals with NDDs remain without a genetic diagnosis after microarray and/or exome sequencing. Here, we aimed to assess the power of short-read genome sequencing (GS), complemented with long-read GS, to identify causal variants in participants with NDD from the National Institute for Health and Care Research (NIHR) BioResource project. Short-read GS was conducted on 692 individuals (489 affected and 203 unaffected relatives) from 465 families. Additionally, long-read GS was performed on five affected individuals who had structural variants (SVs) in technically challenging regions, had complex SVs, or required distal variant phasing. Causal variants were identified in 36% of affected individuals (177/489), and a further 23% (112/489) had a variant of uncertain significance after multiple rounds of re-analysis. Among all reported variants, 88% (333/380) were coding nuclear SNVs or insertions and deletions (indels), and the remainder were SVs, non-coding variants, and mitochondrial variants. Furthermore, long-read GS facilitated the resolution of challenging SVs and invalidated variants of difficult interpretation from short-read GS. This study demonstrates the value of short-read GS, complemented with long-read GS, in investigating the genetic causes of NDDs. GS provides a comprehensive and unbiased method of identifying all types of variants throughout the nuclear and mitochondrial genomes in individuals with NDD.


Asunto(s)
Genoma Humano , Trastornos del Neurodesarrollo , Humanos , Genoma Humano/genética , Mapeo Cromosómico , Secuencia de Bases , Mutación INDEL , Trastornos del Neurodesarrollo/genética
2.
J Med Genet ; 61(2): 163-170, 2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-37816627

RESUMEN

BACKGROUND: Complex regional pain syndrome type 1 (CRPS-1) is a rare, disabling and sometimes chronic disorder usually arising after a trauma. This exploratory study examined whether patients with chronic CRPS-1 have a different genetic profile compared with those who do not have the condition. METHODS: Exome sequencing was performed to seek altered non-synonymous SNP allele frequencies in a discovery cohort of well-characterised patients with chronic CRPS-1 (n=34) compared with population databases. Identified SNP alleles were confirmed by Sanger sequencing and sought in a replication cohort (n=50). Gene expression of peripheral blood macrophages was assessed. RESULTS: In the discovery cohort, the rare allele frequencies of four non-synonymous SNPs were statistically increased. The replication cohort confirmed this finding. In a chronic pain cohort, these alleles were not overexpressed. In total, 25 out of 84 (29.8%) patients with CRPS-1 expressed a rare allele. The SNPs were rs41289586 in ANO10, rs28360457 in P2RX7, rs1126930 in PRKAG1 and rs80308281 in SLC12A9. Males were more likely than females to have a rare SNP allele, 8 out of 14 (57.1%) vs 17 out of 70 (24.3%) (Fisher's p=0.023). ANO10, P2RX7, PRKAG1 and SLC12A9 were all expressed in macrophages from healthy human controls. CONCLUSION: A single SNP in each of the genes ANO10, P2RX7, PRKAG1 and SLC12A9 was associated with developing chronic CRPS-1, with more males than females expressing these rare alleles. Our work suggests the possibility that a permissive genetic background is an important factor in the development of CRPS-1.


Asunto(s)
Síndromes de Dolor Regional Complejo , Masculino , Femenino , Humanos , Síndromes de Dolor Regional Complejo/genética , Síndromes de Dolor Regional Complejo/epidemiología , Frecuencia de los Genes , Polimorfismo de Nucleótido Simple/genética , Alelos , Antecedentes Genéticos
3.
Health Promot Int ; 39(1)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38243778

RESUMEN

The sports clubs' role in promoting health has been acknowledged by policy makers and researchers, but there is little evidence on how sports clubs implement health-related interventions. The present article investigates the Gaelic Athletic Association Healthy Club Project (HCP) implementation process (mechanisms, barriers, leverages) over a 10-year timeframe. A case study design helped to produce and compare a data synthesis for five clubs involved since 2013. A qualitative iterative data collection, including document analysis was conducted through 20 focus groups with Healthy Club Officers, coaches, participants and members. The Consolidated Framework for Implementation Research was used in the deductive analysis process, conducted by the first author. Results have shown the success of the HCP in placing health promotion on the agenda of sports clubs leading to informal policy for health promotion, even if activities and recognition are directed toward and coming from the community. This study also underlines the virtuous cycle of the settings-based approach in enhancing membership and volunteer recognition through health promotion actions, and the importance of social good and corporate social activities for sports clubs. Nevertheless, the HCP still relies on limited human resources, is not recognized by competitive oriented adult playing members. and acknowledged as a resource by some coaches, limiting its rootedness in the core business of sports clubs. Future research should empower the HCP community to focus on organizational changes and develop outcomes for individuals, for the club as a whole as well as for the local community.


Asunto(s)
Deportes , Adulto , Humanos , Irlanda , Promoción de la Salud/métodos , Investigación Cualitativa , Grupos Focales
4.
J Sports Sci ; 41(22): 1983-1993, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38305379

RESUMEN

Identifying tools and processes to effectively and efficiently evaluate technologies is an area of need for many sport stakeholders. This study aimed to develop a standardised, evidence-based framework to guide the evaluation of sports technologies. In developing the framework, a review of standards, guidelines and research into sports technology was conducted. Following this, 55 experts across the sports industry were presented with a draft framework for feedback. Following a two-round Delphi survey, the final framework consisted of 25 measurable features grouped under five quality pillars. These were 1) Quality Assurance & Measurement (Accuracy, Repeatability, Reproducibility, Specifications), 2) Established Benefit (Construct Validity, Concurrent Validity, Predictive Validity, Functionality), 3) Ethics & Security (Compliance, Privacy, Ownership, Safety, Transparency, Environmental Sustainability), 4) User Experience (Usability, Robustness, Data Representation, Customer Support & Training, Accessibility) & 5) Data Management (Data Standardisation, Interoperability, Maintainability, Scalability). The framework can be used to help design and refine sports technology in order to optimise quality and maintain industry standards, as well as guide purchasing decisions by organisations. It may also serve to create a common language for organisations, manufacturers, investors, and consumers to improve the efficiency of their decision-making relating to sports technology.


Asunto(s)
Deportes , Humanos , Reproducibilidad de los Resultados , Tecnología , Predicción
5.
BMC Health Serv Res ; 22(1): 657, 2022 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-35578247

RESUMEN

BACKGROUND: The Southern Province of Sri Lanka is endemic with dengue, with frequent outbreaks and occurrence of severe disease. However, the economic burden of dengue is poorly quantified. Therefore, we conducted a cost analysis to assess the direct and indirect costs associated with hospitalized patients with dengue to households and to the public healthcare system. METHODS: From June 2017-December 2018, we prospectively enrolled children and adults with acute dengue hospitalized at the largest, public tertiary-care (1800 bed) hospital in the Southern Province, Sri Lanka. We administered a structured questionnaire to obtain information regarding direct costs spent by households on medical visits, medications, laboratory testing, and travel for seeking care for the illness. Indirect costs lost by households were estimated by identifying the days of work lost by patients and caregivers and school days lost by children. Direct hospital costs were estimated using gross costing approach and adjusted by multiplying by annual inflation rates in Sri Lankan rupees and converted to US dollars. RESULTS: A total of 1064 patients with laboratory-confirmed dengue were enrolled. The mean age (SD) was 35.9 years (15.6) with male predominance (66.2%). The mean durations of hospitalization for adults and paediatric patients were 3.86 (SD = 1.51) and 4 (SD = 1.32) days, respectively. The per-capita direct cost borne by the healthcare system was 233.76 USD, and was approximately 14 times greater than the per-capita direct cost borne by households (16.29 USD, SD = 14.02). The per-capita average number of loss of working days was 21.51 (SD = 41.71), with mean per-capita loss of income due to loss of work being 303.99 USD (SD = 569.77), accounting for over 70% of average monthly income. On average, 10.88 days (SD = 10.97) of school days were missed due to the dengue episode. School misses were expected to reduce future annual income of affected children by 0.44%. CONCLUSIONS: Dengue requiring hospitalization had a substantial economic burden on the public healthcare system in Sri Lanka and the affected households. These findings emphasize the importance of strengthening dengue control activities and improved use of hospital-based resources for care to reduce the economic impact of dengue in Sri Lanka.


Asunto(s)
Dengue , Hospitalización , Adulto , Niño , Dengue/epidemiología , Dengue/terapia , Composición Familiar , Femenino , Costos de Hospital , Humanos , Masculino , Sri Lanka/epidemiología
6.
Public Health ; 209: 46-51, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35809350

RESUMEN

OBJECTIVES: Healthcare worker (HCW) SARS-CoV-2 contacts in England have been required to quarantine, creating staff shortages. We piloted daily contact testing (DCT) to assess its feasibility as an alternative. STUDY DESIGN: Observational service evaluation. METHODS: We conducted an observational service evaluation of 7-day DCT using antigen lateral flow devices (LFDs) at four acute hospital trusts and one ambulance trust in England. Mixed methods were used, using aggregate and individual-level test monitoring data, semi-structured interviews, and a survey of eligible contacts. RESULTS: In total, 138 HCWs were identified as contacts of a confirmed SARS-CoV-2 case. Of these, 111 (80%) consented to daily LFD testing, of whom 82 (74%) completed the required programme without interruption and 12 (11%) completed with interruption. Fifty-eight participants (52%) and two non-participants (7.4%) completed the survey. In total, 28 interviews were conducted with participants, site and infection control leads, and union representatives. One participant tested positive on LFD and polymerase chain reaction (PCR) test. Three participants tested positive on PCR but not LFD. DCT was well-accepted by trusts and staff. Participants reported no relaxation of their infection prevention and control behaviours. No incidents of transmission were detected. An estimated 729 potential days of work absence were averted. CONCLUSIONS: DCT can be acceptably operated in a healthcare setting, averting quarantine-related work absences in HCW SARS-CoV-2 contacts.


Asunto(s)
COVID-19 , SARS-CoV-2 , Ambulancias , COVID-19/diagnóstico , Inglaterra , Hospitales , Humanos
7.
Eur Phys J A Hadron Nucl ; 58(12): 239, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36514540

RESUMEN

Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.

8.
Ir Med J ; 115(3): 560, 2022 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-35532732

RESUMEN

Aim Physical Activity (PA) and Mindfulness-Based Stress Reduction (MBSR) both have positive effects on medical student well-being. The 'MED-WELL' programme is a curricular intervention that combines PA and education on exercise as medicine. This trial evaluates whether there is a mean difference in outcomes of participants of an exercise intervention, the 'MED-WELL' programme, versus a control group which engages in a MBSR programme. Methods All second-year medical students were voluntarily allocated into the intervention or control group. Data on overall health and well-being, sleep quality, loneliness, current level of PA, and confidence in prescribing exercise as medicine was analysed from both groups at baseline and after eight weeks. Results Within groups the intervention and control groups showed statistically significant improvements in overall well-being (p=0.010, p=0.005 respectively) and in sleep quality (p<0.001, p=0.007 respectively). The intervention group had statistically significant improvements in levels of PA (p=0.003) and confidence in prescribing exercise (p<0.001). However, there were no statistically significant differences in changes in outcome measures between groups. Conclusion This study has shown that participants in an exercise intervention, the 'MED-WELL' programme, had similar improvements in overall wellbeing and sleep quality to those in a control group who participated in a MBSR programme of the same duration.


Asunto(s)
Atención Plena , Estudiantes de Medicina , Ejercicio Físico , Humanos , Atención Plena/métodos , Evaluación de Resultado en la Atención de Salud
9.
Phys Rev Lett ; 127(20): 202501, 2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34860042

RESUMEN

Two long-standing puzzles in the decay of ^{185}Bi, the heaviest known proton-emitting nucleus are revisited. These are the nonobservation of the 9/2^{-} state, which is the ground state of all heavier odd-A Bi isotopes, and the hindered nature of proton and α decays of its presumed 60-µs 1/2^{+} ground state. The ^{185}Bi nucleus has now been studied with the ^{95}Mo(^{93}Nb,3n) reaction in complementary experiments using the Fragment Mass Analyzer and Argonne Gas-Filled Analyzer at Argonne National Laboratory's ATLAS facility. The experiments have established the existence of two states in ^{185}Bi; the short-lived T_{1/2}=2.8_{-1.0}^{+2.3} µs, proton- and α-decaying ground state, and a 58(2)-µs γ-decaying isomer, the half-life of which was previously attributed to the ground state. The reassignment of the ground-state lifetime results in a proton-decay spectroscopic factor close to unity and represents the only known example of a ground-state proton decay to a daughter nucleus (^{184}Pb) with a major shell closure. The data also demonstrate that the ordering of low- and high-spin states in ^{185}Bi is reversed relative to the heavier odd-A Bi isotopes, with the intruder-based 1/2^{+} configuration becoming the ground, similar to the lightest At nuclides.

10.
Phys Rev Lett ; 127(16): 162501, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34723594

RESUMEN

We report an improved measurement of the free neutron lifetime τ_{n} using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_{n} from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_{n} measurements and by performing a global likelihood fit to all data while self-consistently incorporating the ß-decay lifetime. Both techniques achieve consistent results and find a value τ_{n}=877.75±0.28_{stat}+0.22/-0.16_{syst} s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.

11.
Diabet Med ; 38(6): e14412, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32997841

RESUMEN

AIMS: To establish the impact of uncomplicated type 2 diabetes on cognitive and neuropsychological performance in midlife. METHODS: We performed a cross-sectional study of middle-aged adults with uncomplicated type 2 diabetes and a cohort of healthy control participants. General cognition was assessed using the Montreal Cognitive Assessment test and neuropsychological assessment was undertaken using a detailed neuropsychological assessment battery. RESULTS: A total of 152 participants (102 with type 2 diabetes and 50 controls) were recruited (mean age 52 ± 8 years, 51% women). Participants with midlife type 2 diabetes were more than twice as likely to make an error on the Montreal Cognitive Assessment test [incidence rate ratio 2.44 (95% CI 1.54 to 3.87); P < 0.001]. Further, type 2 diabetes was also associated with significantly lower memory composite score [ß: -0.20 (95% CI -0.39 to -0.01); P = 0.04] and paired associates learning score [ß: = -1.97 (95% CI -3.51, -0.43); P = 0.01] on the neuropsychological assessment battery following adjustment for age, sex, BMI, educational attainment and hypercholesterolaemia. CONCLUSIONS: Even in midlife, type 2 diabetes was associated with small but statistically significant cognitive decrements. These statistically significant decrements, whilst not clinically significant in terms of objective cognitive impairment, may have important implications in selecting out individuals most at risk of later cognitive decline for potential preventative interventions in midlife.


Asunto(s)
Cognición/fisiología , Disfunción Cognitiva/etiología , Diabetes Mellitus Tipo 2/complicaciones , Memoria/fisiología , Adulto , Anciano , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/psicología , Estudios Transversales , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/psicología , Escolaridad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Irlanda/epidemiología , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Pruebas Neuropsicológicas , Factores de Riesgo
12.
Am J Hum Genet ; 100(5): 706-724, 2017 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-28413018

RESUMEN

During neurotransmission, synaptic vesicles undergo multiple rounds of exo-endocytosis, involving recycling and/or degradation of synaptic proteins. While ubiquitin signaling at synapses is essential for neural function, it has been assumed that synaptic proteostasis requires the ubiquitin-proteasome system (UPS). We demonstrate here that turnover of synaptic membrane proteins via the endolysosomal pathway is essential for synaptic function. In both human and mouse, hypomorphic mutations in the ubiquitin adaptor protein PLAA cause an infantile-lethal neurodysfunction syndrome with seizures. Resulting from perturbed endolysosomal degradation, Plaa mutant neurons accumulate K63-polyubiquitylated proteins and synaptic membrane proteins, disrupting synaptic vesicle recycling and neurotransmission. Through characterization of this neurological intracellular trafficking disorder, we establish the importance of ubiquitin-mediated endolysosomal trafficking at the synapse.


Asunto(s)
Epilepsia/genética , Proteínas/genética , Espasmos Infantiles/genética , Transmisión Sináptica , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Modelos Animales de Enfermedad , Epilepsia/diagnóstico , Fibroblastos/metabolismo , Técnicas de Genotipaje , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética , Ratones , Ratones Transgénicos , Mutación , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Conformación Proteica , Proteínas/metabolismo , Células de Purkinje/metabolismo , Espasmos Infantiles/diagnóstico , Vesículas Sinápticas/metabolismo , Transcriptoma , Ubiquitina/genética , Ubiquitina/metabolismo
13.
J Transl Med ; 18(1): 280, 2020 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-32650803

RESUMEN

BACKGROUND: Oropharyngeal squamous cell carcinoma (OPSCC) is often diagnosed at an advanced stage because the disease often causes minimal symptoms other than metastasis to neck lymph nodes. Better tools are required to assist with the early detection of OPSCC. MicroRNAs (miRNAs, miRs) are potential biomarkers for early head and neck squamous cell cancer diagnosis, prognosis, recurrence, and presence of metastatic disease. However, there is no widespread agreement on a panel of miRNAs with clinically meaningful utility for head and neck squamous cell cancers. This could be due to variations in the collection, storage, pre-processing, and isolation of RNA, but several reports have indicated that the selection and reproducibility of biomarkers has been widely affected by the methods used for data analysis. The primary analysis issues appear to be model overfitting and the incorrect application of statistical techniques. The purpose of this study was to develop a robust statistical approach to identify a miRNA signature that can distinguish controls and patients with inflammatory disease from patients with human papilloma virus positive (HPV +) OPSCC. METHODS: Small extracellular vesicles were harvested from the serum of 20 control patients, 20 patients with gastroesophageal reflux disease (GORD), and 40 patients with locally advanced HPV + OPSCC. MicroRNAs were purified, and expression profiled on OpenArray™. A novel cross validation method, using lasso regression, was developed to stabilise selection of miRNAs for inclusion in a prediction model. The method, named StaVarSel (for Stable Variable Selection), was used to derive a diagnostic biomarker signature. RESULTS: A standard cross validation approach was unable to produce a biomarker signature with good cross validated predictive capacity. In contrast, StaVarSel produced a regression model containing 11 miRNA ratios with potential clinical utility. Sample permutations indicated that the estimated cross validated prediction accuracy of the 11-miR-ratio model was not due to chance alone. CONCLUSIONS: We developed a novel method, StaVarSel, that was able to identify a panel of miRNAs, present in small extracellular vesicles derived from blood serum, that robustly cross validated as a biomarker for the detection of HPV + OPSCC. This approach could be used to derive diagnostic biomarkers of other head and neck cancers.


Asunto(s)
Carcinoma de Células Escamosas , Vesículas Extracelulares , Neoplasias de Cabeza y Cuello , MicroARNs , Neoplasias Orofaríngeas , Infecciones por Papillomavirus , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/genética , Neoplasias de Cabeza y Cuello/diagnóstico , Neoplasias de Cabeza y Cuello/genética , Humanos , MicroARNs/genética , Recurrencia Local de Neoplasia , Neoplasias Orofaríngeas/diagnóstico , Neoplasias Orofaríngeas/genética , Papillomaviridae , Reproducibilidad de los Resultados , Suero , Carcinoma de Células Escamosas de Cabeza y Cuello/diagnóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/genética
14.
Phys Rev Lett ; 122(9): 092701, 2019 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-30932526

RESUMEN

We report the first measurement of low-energy proton-capture cross sections of ^{124}Xe in a heavy-ion storage ring. ^{124}Xe^{54+} ions of five different beam energies between 5.5 and 8 AMeV were stored to collide with a windowless hydrogen target. The ^{125}Cs reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and x-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron and γ widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.

15.
Brain ; 141(7): 1934-1945, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29868776

RESUMEN

The post-translational modification of proteins through the addition of UFM1, also known as ufmylation, plays a critical developmental role as revealed by studies in animal models. The recent finding that biallelic mutations in UBA5 (the E1-like enzyme for ufmylation) cause severe early-onset encephalopathy with progressive microcephaly implicates ufmylation in human brain development. More recently, a homozygous UFM1 variant was proposed as a candidate aetiology of severe early-onset encephalopathy with progressive microcephaly. Here, we establish a locus for severe early-onset encephalopathy with progressive microcephaly based on two families, and map the phenotype to a novel homozygous UFM1 mutation. This mutation has a significantly diminished capacity to form thioester intermediates with UBA5 and with UFC1 (the E2-like enzyme for ufmylation), with resulting impaired ufmylation of cellular proteins. Remarkably, in four additional families where eight children have severe early-onset encephalopathy with progressive microcephaly, we identified two biallelic UFC1 mutations, which impair UFM1-UFC1 intermediate formation with resulting widespread reduction of cellular ufmylation, a pattern similar to that observed with UFM1 mutation. The striking resemblance between UFM1- and UFC1-related clinical phenotype and biochemical derangements strongly argues for an essential role for ufmylation in human brain development. The hypomorphic nature of UFM1 and UFC1 mutations and the conspicuous depletion of biallelic null mutations in the components of this pathway in human genome databases suggest that it is necessary for embryonic survival, which is consistent with the embryonic lethal nature of knockout models for the orthologous genes.


Asunto(s)
Encefalopatías/genética , Proteínas/genética , Enzimas Ubiquitina-Conjugadoras/genética , Adolescente , Adulto , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Encefalopatías/fisiopatología , Niño , Preescolar , Femenino , Células HEK293 , Humanos , Masculino , Microcefalia/genética , Mutación , Linaje , Procesamiento Proteico-Postraduccional , Proteínas/fisiología , Enzimas Activadoras de Ubiquitina/genética , Enzimas Ubiquitina-Conjugadoras/fisiología
16.
Nature ; 497(7451): 594-7, 2013 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-23676678

RESUMEN

Superlattices have attracted great interest because their use may make it possible to modify the spectra of two-dimensional electron systems and, ultimately, create materials with tailored electronic properties. In previous studies (see, for example, refs 1-8), it proved difficult to realize superlattices with short periodicities and weak disorder, and most of their observed features could be explained in terms of cyclotron orbits commensurate with the superlattice. Evidence for the formation of superlattice minibands (forming a fractal spectrum known as Hofstadter's butterfly) has been limited to the observation of new low-field oscillations and an internal structure within Landau levels. Here we report transport properties of graphene placed on a boron nitride substrate and accurately aligned along its crystallographic directions. The substrate's moiré potential acts as a superlattice and leads to profound changes in the graphene's electronic spectrum. Second-generation Dirac points appear as pronounced peaks in resistivity, accompanied by reversal of the Hall effect. The latter indicates that the effective sign of the charge carriers changes within graphene's conduction and valence bands. Strong magnetic fields lead to Zak-type cloning of the third generation of Dirac points, which are observed as numerous neutrality points in fields where a unit fraction of the flux quantum pierces the superlattice unit cell. Graphene superlattices such as this one provide a way of studying the rich physics expected in incommensurable quantum systems and illustrate the possibility of controllably modifying the electronic spectra of two-dimensional atomic crystals by varying their crystallographic alignment within van der Waals heterostuctures.

17.
J Med Genet ; 55(12): 803-813, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30287594

RESUMEN

BACKGROUND: Progressive encephalopathy, hypsarrhythmia and optic atrophy (PEHO) has been described as a clinically distinct syndrome. It has been postulated that it is an autosomal recessive condition. However, the aetiology is poorly understood, and the genetic basis of the condition has not been fully elucidated. Our objective was to discover if PEHO syndrome is a single gene disorder. METHOD: Children with PEHO and PEHO-like syndrome were recruited. Clinical, neurological and dysmorphic features were recorded; EEG reports and MRI scans were reviewed. Where possible, exome sequencing was carried out first to seek mutations in known early infantile developmental and epileptic encephalopathy (DEE) genes and then to use an agnostic approach to seek novel candidate genes. We sought intra-interfamilial phenotypic correlations and genotype-phenotype correlations when pathological mutations were identified. RESULTS: Twenty-three children were recruited from a diverse ethnic background, 19 of which were suitable for inclusion. They were similar in many of the core and the supporting features of PEHO, but there was significant variation in MRI and ophthalmological findings, even between siblings with the same mutation. A pathogenic genetic variant was identified in 15 of the 19 children. One further girl's DNA failed analysis, but her two affected sisters shared confirmed variants. Pathogenic variants were identified in seven different genes. CONCLUSIONS: We found significant clinical and genetic heterogeneity. Given the intrafamily variation demonstrated, we question whether the diagnostic criteria for MRI and ophthalmic findings should be altered. We also question whether PEHO and PEHO-like syndrome represent differing points on a clinical spectrum of the DEE. We conclude that PEHO and PEHO-like syndrome are clinically and genetically diverse entities-and are phenotypic endpoints of many severe genetic encephalopathies.


Asunto(s)
Edema Encefálico/diagnóstico , Edema Encefálico/etiología , Epilepsia/diagnóstico , Epilepsia/genética , Enfermedades Neurodegenerativas/diagnóstico , Enfermedades Neurodegenerativas/etiología , Atrofia Óptica/diagnóstico , Atrofia Óptica/etiología , Espasmos Infantiles/diagnóstico , Espasmos Infantiles/etiología , Factores de Edad , Alelos , Biomarcadores , Preescolar , Electroencefalografía , Facies , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Genotipo , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética , Masculino , Mutación , Linaje , Fenotipo
18.
Hum Mutat ; 39(3): 319-332, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29243349

RESUMEN

Autosomal recessive microcephaly or microcephaly primary hereditary (MCPH) is a genetically heterogeneous neurodevelopmental disorder characterized by a reduction in brain volume, indirectly measured by an occipitofrontal circumference (OFC) 2 standard deviations or more below the age- and sex-matched mean (-2SD) at birth and -3SD after 6 months, and leading to intellectual disability of variable severity. The abnormal spindle-like microcephaly gene (ASPM), the human ortholog of the Drosophila melanogaster "abnormal spindle" gene (asp), encodes ASPM, a protein localized at the centrosome of apical neuroprogenitor cells and involved in spindle pole positioning during neurogenesis. Loss-of-function mutations in ASPM cause MCPH5, which affects the majority of all MCPH patients worldwide. Here, we report 47 unpublished patients from 39 families carrying 28 new ASPM mutations, and conduct an exhaustive review of the molecular, clinical, neuroradiological, and neuropsychological features of the 282 families previously reported (with 161 distinct ASPM mutations). Furthermore, we show that ASPM-related microcephaly is not systematically associated with intellectual deficiency and discuss the association between the structural brain defects (strong reduction in cortical volume and surface area) that modify the cortical map of these patients and their cognitive abilities.


Asunto(s)
Microcefalia/genética , Mutación/genética , Proteínas del Tejido Nervioso/genética , Preescolar , Cognición , Estudios de Cohortes , Familia , Femenino , Estudios de Asociación Genética , Geografía , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Microcefalia/epidemiología
19.
Mol Pain ; 14: 1744806918809223, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30296891

RESUMEN

Bi-allelic dysfunctional mutations in nerve growth factor (NGF) cause the rare human phenotype hereditary sensory and autonomic neuropathy type 5 (HSAN5). We describe a novel NGF mutation in an individual with typical HSAN5 findings. The mutation c.361C>T, p.R121W is at the last residue of the furin cleavage motif Arg-Ser-Lys-Arg in proNGF. We show that the p.R121W mutation completely abolishes the formation of mature NGF-ß. Surprisingly, mutant p.R121W cells produced very little proNGF. Instead, the two progressive cleavage products of proNGF were produced, proA-NGF and proB-NGF, with proB-NGF being the predominant NGF-derived peptide and the only peptide secreted by mutant p.R121W cells. We found that the ability of the p.R121W mutation to cause tropomyosin receptor kinase A autophosphorylation and mitogen-activated protein kinase phosphorylation was significantly reduced compared to controls (p < 0.05 and p < 0.01). By studying the PC12 cell line morphology and neurite length over a week, we found the p.R121W mutation had residual, but much reduced, neurotrophic activity when compared to wild-type NGF. Finally, we assessed whether the p.R121W mutation affected apoptosis and found a reduced protective effect compared to wild-type NGF. Our results suggest that the p.R121W NGF mutation causes HSAN5 through negating the ability of furin to cleave proNGF to produce NGF-ß.


Asunto(s)
Neuropatías Hereditarias Sensoriales y Autónomas/genética , Mutación/genética , Factor de Crecimiento Nervioso/metabolismo , Neuritas/metabolismo , Neuronas/metabolismo , Animales , Neuropatías Hereditarias Sensoriales y Autónomas/metabolismo , Células PC12 , Fosforilación/genética , Precursores de Proteínas/metabolismo , Ratas
20.
Phys Rev Lett ; 121(2): 022505, 2018 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-30085691

RESUMEN

Fornal and Grinstein recently proposed that the discrepancy between two different methods of neutron lifetime measurements, the beam and bottle methods, can be explained by a previously unobserved dark matter decay mode, n→X+γ. We perform a search for this decay mode over the allowed range of energies of the monoenergetic γ ray for X to be dark matter. A Compton-suppressed high-purity germanium detector is used to identify γ rays from neutron decay in a nickel-phosphorous-coated stainless-steel bottle. A combination of Monte Carlo and radioactive source calibrations is used to determine the absolute efficiency for detecting γ rays arising from the dark matter decay mode. We exclude the possibility of a sufficiently strong branch to explain the lifetime discrepancy with 97% confidence.

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