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1.
Hepatology ; 79(5): 1075-1087, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37976411

RESUMO

BACKGROUND AND AIMS: Pediatric acute liver failure (PALF) is a life-threatening condition. In Europe, the main causes are viral infections (12%-16%) and inherited metabolic diseases (14%-28%). Yet, in up to 50% of cases the underlying etiology remains elusive, challenging clinical management, including liver transplantation. We systematically studied indeterminate PALF cases referred for genetic evaluation by whole-exome sequencing (WES), and analyzed phenotypic and biochemical markers, and the diagnostic yield of WES in this condition. APPROACH AND RESULTS: With this international, multicenter observational study, patients (0-18 y) with indeterminate PALF were analyzed by WES. Data on the clinical and biochemical phenotype were retrieved and systematically analyzed. RESULTS: In total, 260 indeterminate PALF patients from 19 countries were recruited between 2011 and 2022, of whom 59 had recurrent PALF. WES established a genetic diagnosis in 37% of cases (97/260). Diagnostic yield was highest in children with PALF in the first year of life (41%), and in children with recurrent acute liver failure (64%). Thirty-six distinct disease genes were identified. Defects in NBAS (n=20), MPV17 (n=8), and DGUOK (n=7) were the most frequent findings. When categorizing, the most frequent were mitochondrial diseases (45%), disorders of vesicular trafficking (28%), and cytosolic aminoacyl-tRNA synthetase deficiencies (10%). One-third of patients had a fatal outcome. Fifty-six patients received liver transplantation. CONCLUSIONS: This study elucidates a large contribution of genetic causes in PALF of indeterminate origin with an increasing spectrum of disease entities. The high proportion of diagnosed cases and potential treatment implications argue for exome or in future rapid genome sequencing in PALF diagnostics.


Assuntos
Falência Hepática Aguda , Transplante de Fígado , Criança , Humanos , Recidiva Local de Neoplasia , Falência Hepática Aguda/diagnóstico , Biomarcadores , Transplante de Fígado/efeitos adversos , Europa (Continente)
2.
Genet Med ; 26(2): 101013, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37924258

RESUMO

PURPOSE: RNF213, encoding a giant E3 ubiquitin ligase, has been recognized for its role as a key susceptibility gene for moyamoya disease. Case reports have also implicated specific variants in RNF213 with an early-onset form of moyamoya disease with full penetrance. We aimed to expand the phenotypic spectrum of monogenic RNF213-related disease and to evaluate genotype-phenotype correlations. METHODS: Patients were identified through reanalysis of exome sequencing data of an unselected cohort of unsolved pediatric cases and through GeneMatcher or ClinVar. Functional characterization was done by proteomics analysis and oxidative phosphorylation enzyme activities using patient-derived fibroblasts. RESULTS: We identified 14 individuals from 13 unrelated families with (de novo) missense variants in RNF213 clustering within or around the Really Interesting New Gene (RING) domain. Individuals presented either with early-onset stroke (n = 11) or with Leigh syndrome (n = 3). No genotype-phenotype correlation could be established. Proteomics using patient-derived fibroblasts revealed no significant differences between clinical subgroups. 3D modeling revealed a clustering of missense variants in the tertiary structure of RNF213 potentially affecting zinc-binding suggesting a gain-of-function or dominant negative effect. CONCLUSION: De novo missense variants in RNF213 clustering in the E3 RING or other regions affecting zinc-binding lead to an early-onset syndrome characterized by stroke or Leigh syndrome.


Assuntos
Doença de Leigh , Doença de Moyamoya , Acidente Vascular Cerebral , Humanos , Criança , Doença de Moyamoya/genética , Doença de Leigh/complicações , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/genética , Zinco , Predisposição Genética para Doença , Adenosina Trifosfatases/genética
3.
Ergonomics ; : 1-15, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557363

RESUMO

Adverse drug events (ADEs) are common in hospitals, affecting one in six child in-patients. Medication processes are complex systems. This study aimed to explore the work-as-done of medication safety in three English paediatric units using direct observation and semi-structured interviews. We found that a combination of the physical environment, traditional work systems and team norms were among the systemic barriers to medicines safety. The layout of wards discouraged teamworking and reinforced professional boundaries. Workspaces were inadequate, and interruptions were uncontrollable. A less experienced workforce undertook prescribing and verification while more experienced nurses undertook administration. Guidelines were inadequate, with actors muddling through together. Formal controls against ADEs included checking (of prescriptions and administration) and barcode administration systems, but these did not integrate into workflows. Families played an important part in the safe administration of medication and provision of information about their children but were isolated from other parts of the system.


Formal medicines safety processes in paediatric units are disjointed and disconnected. This has led actors in the system (e.g. nursing and medical staff) to develop informal adaptations to increase resilience. There is a need to incorporate these adaptations into a systems-focussed consideration of safety processes, in order to properly inform the development of medication safety interventions.

4.
Genet Med ; 25(6): 100314, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36305855

RESUMO

PURPOSE: This study aimed to define the genotypic and phenotypic spectrum of reversible acute liver failure (ALF) of infancy resulting from biallelic pathogenic TRMU variants and determine the role of cysteine supplementation in its treatment. METHODS: Individuals with biallelic (likely) pathogenic variants in TRMU were studied within an international retrospective collection of de-identified patient data. RESULTS: In 62 individuals, including 30 previously unreported cases, we described 47 (likely) pathogenic TRMU variants, of which 17 were novel, and 1 intragenic deletion. Of these 62 individuals, 42 were alive at a median age of 6.8 (0.6-22) years after a median follow-up of 3.6 (0.1-22) years. The most frequent finding, occurring in all but 2 individuals, was liver involvement. ALF occurred only in the first year of life and was reported in 43 of 62 individuals; 11 of whom received liver transplantation. Loss-of-function TRMU variants were associated with poor survival. Supplementation with at least 1 cysteine source, typically N-acetylcysteine, improved survival significantly. Neurodevelopmental delay was observed in 11 individuals and persisted in 4 of the survivors, but we were unable to determine whether this was a primary or a secondary consequence of TRMU deficiency. CONCLUSION: In most patients, TRMU-associated ALF was a transient, reversible disease and cysteine supplementation improved survival.


Assuntos
Falência Hepática Aguda , Falência Hepática , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Adulto Jovem , Acetilcisteína/uso terapêutico , Falência Hepática/tratamento farmacológico , Falência Hepática/genética , Falência Hepática Aguda/tratamento farmacológico , Falência Hepática Aguda/genética , Proteínas Mitocondriais/genética , Mutação , Estudos Retrospectivos , tRNA Metiltransferases/genética
5.
Health Expect ; 25(4): 1192-1199, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35322513

RESUMO

BACKGROUND: Healthcare is not without risk. Despite two decades of policy focus and improvement efforts, the global incidence of harm remains stubbornly persistent, with estimates suggesting that 10% of hospital patients are affected by adverse events. METHODS: We explore how current investigative responses can compound the harm for all those affected-patients, families, health professionals and organizations-by neglecting to appreciate and respond to the human impacts. We suggest that the risk of compounded harm may be reduced when investigations respond to the need for healing alongside system learning, with the former having been consistently neglected. DISCUSSION: We argue that incident responses must be conceived within a relational as well as a regulatory framework, and that this-a restorative approach-has the potential to radically shift the focus, conduct and outcomes of investigative processes. CONCLUSION: The identification of the preconditions and mechanisms that enable the success of restorative approaches in global health systems and legal contexts is required if their demonstrated potential is to be realized on a larger scale. The policy must be co-created by all those who will be affected by reforms and be guided by restorative principles. PATIENT OR PUBLIC CONTRIBUTION: This viewpoint represents an international collaboration between a clinician academic, safety scientist and harmed patient and family members. The paper incorporates key findings and definitions from New Zealand's restorative response to surgical mesh harm, which was co-designed with patient advocates, academics and clinicians.


Assuntos
Família , Médicos , Pessoal de Saúde , Humanos , Pacientes Internados , Segurança do Paciente
6.
BMC Health Serv Res ; 22(1): 1103, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042434

RESUMO

BACKGROUND: Infectious illness is the biggest cause of death in children due to a physical illness, particularly in children under five years. If mortality is to be reduced for this group of children, it is important to understand factors affecting their pathways to hospital. The aim of this study was to retrospectively identify organisational and environmental factors, and individual child, family, and professional factors affecting timing of admission to hospital for children under five years of age with a serious infectious illness (SII). METHODS: An explanatory modified grounded theory design was used in collaboration with parents. Two stages of data collection were conducted: Stage 1, interviews with 22 parents whose child had recently been hospitalised with a SII and 14 health professionals (HPs) involved in their pre-admission trajectories; Stage 2, focus groups with 18 parents and 16 HPs with past experience of SII in young children. Constant comparative analysis generated the explanatory theory. RESULTS: The core category was 'navigating uncertain illness trajectories for young children with serious infectious illness'. Uncertainty was prevalent throughout the parents' and HPs' stories about their experiences of navigating social rules and overburdened health services for these children. The complexity of and lack of continuity within services, family lives, social expectations and hierarchies provided the context and conditions for children's, often complex, illness trajectories. Parents reported powerlessness and perceived criticism leading to delayed help-seeking. Importantly, parents and professionals missed symptoms of serious illness. Risk averse services were found to refer more children to emergency departments. CONCLUSIONS: Parents and professionals have difficulties recognising signs of SII in young children and can feel socially constrained from seeking help. The increased burden on services has made it more difficult for professionals to spot the seriously ill child.


Assuntos
Doenças Transmissíveis , Pais , Pré-Escolar , Família , Teoria Fundamentada , Humanos , Estudos Retrospectivos , Incerteza
7.
Compr Rev Food Sci Food Saf ; 21(3): 2391-2432, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35279935

RESUMO

Meat quality can be affected by stress, exhaustion, feed composition, and other physical and environmental conditions. These stressors can alter the pH in postmortem muscle, leading to high pH and low-quality dark cutting (DC) beef, resulting in considerable economic loss. Moreover, the dark cutting prediction may equally provide a measure for animal welfare since it is directly related to animal stress. There are two needs to advance on-site detection of dark cutters: (1) a clear indication that biomarker (signature compounds) levels in cattle correlate with stress and DC outcome; and (2) measuring these biomarkers rapidly and accurately on-farm or the abattoir, depending on the objectives. This critical review assesses which small molecules and proteins have been identified as potential biomarkers of stress and dark cutting in cattle. We discuss the potential of promising small molecule biomarkers, including catecholamine/cortisol metabolites, lactate, succinate, inosine, glucose, and ß-hydroxybutyrate, and we identify a clear research gap for proteomic biomarker discovery in live cattle. We also explore the potential of chemical-sensing and biosensing technologies, including direct electrochemical detection improved through nanotechnology (e.g., carbon and gold nanostructures), surface-enhanced Raman spectroscopy in combination with chemometrics, and commercial hand-held devices for small molecule detection. No current strategy exists to rapidly detect predictive meat quality biomarkers due to the need to further validate biomarkers and the fact that different biosensor types are needed to optimally detect different molecules. Nonetheless, several biomarker/biosensor combinations reported herein show excellent potential to enable the measurement of DC potential in live cattle.


Assuntos
Técnicas Biossensoriais , Proteômica , Animais , Biomarcadores/análise , Biomarcadores/metabolismo , Bovinos , Concentração de Íons de Hidrogênio , Músculo Esquelético/química
8.
J Inherit Metab Dis ; 44(3): 639-655, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33300147

RESUMO

Since 1972, 18 patients (10 females/8 males) have been detected by newborn bloodspot screening (NBS) with neonatal-onset maple syrup urine disease (MSUD) in Ireland. Patients were stratified into three clusters according to clinical outcome at the time of data collection, including developmental, clinical, and IQ data. A fourth cluster comprised of two early childhood deaths; a third patient died as an adult. We present neuroimaging and electroencephalography together with clinical and biochemical data. Incidence of MSUD (1972-2018) was 1 in 147 975. Overall good clinical outcomes were achieved with 15/18 patients alive and with essentially normal functioning (with only the lowest performing cluster lying beyond a single SD on their full scale intelligence quotient). Molecular genetic analysis revealed genotypes hitherto not reported, including a possible digenic inheritance state for the BCKDHA and DBT genes in one family. Treatment has been based on early implementation of emergency treatment, diet, close monitoring, and even dialysis in the setting of acute metabolic decompensation. A plasma leucine ≥400 µmol/L (outside therapeutic range) was more frequently observed in infancy or during adolescence, possibly due to infections, hormonal changes, or noncompliance. Children require careful management during metabolic decompensations in early childhood, and this represented a key risk period in our cohort. A high level of metabolic control can be achieved through diet with early implementation of a "sick day" regime and, in some cases, dialysis as a rescue therapy. The Irish cohort, despite largely classical phenotypes, achieved good outcomes in the NBS era, underlining the importance of early diagnosis and skilled multidisciplinary team management.


Assuntos
Doença da Urina de Xarope de Bordo/diagnóstico , Doença da Urina de Xarope de Bordo/genética , Adolescente , Criança , Pré-Escolar , Dieta com Restrição de Proteínas , Teste em Amostras de Sangue Seco , Diagnóstico Precoce , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Irlanda , Leucina/sangue , Masculino , Triagem Neonatal/métodos , Fenótipo , Estudos Retrospectivos
9.
Health Expect ; 24(6): 2036-2046, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34407286

RESUMO

BACKGROUND: During the COVID-19 pandemic, the first UK lockdown (March to May 2020) witnessed a dramatic reduction in children presenting to primary/emergency care, creating concern that fear of the virus was resulting in children presenting late. METHODS: An online survey was co-developed with UK parents to understand the impact of the lockdown on parents' help-seeking for, and care of, their sick/injured child(ren). The survey was advertised through social media and snowballing to parents whose children had been ill/injured during the lockdown. Analysis used descriptive statistics, SPSSv25 and thematic analysis. RESULTS: The survey was fully completed by 198 UK parents. The majority asked for help (144/198): from their family doctor (78), national helplines (48) or an Emergency Department (23). Most reported that their decision-making had not changed, although how they sought help had changed. A few parents reported that the severity and duration of illness had increased because of uncertainty about and/or difficulty accessing services. Parents did not always report seeking help for symptoms rated red or amber by the Royal College of Paediatrics and Child Health. Parents reported accessing information through the internet or using information that they already had. PARENT CONTRIBUTION: This was a collaboration with parents from survey development to dissemination, with two parents being integral members of our research team. CONCLUSIONS: Our questionnaire was completed by parents who were not deterred from seeking help for their sick or injured children. Even for these parents, the lockdown changes to services created uncertainty about, and barriers to, accessing medical help for their children.


Assuntos
COVID-19 , Pandemias , Criança , Controle de Doenças Transmissíveis , Humanos , Pais , SARS-CoV-2 , Inquéritos e Questionários , Reino Unido
10.
Genet Med ; 22(11): 1863-1873, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32699352

RESUMO

PURPOSE: Biallelic variants in LARS1, coding for the cytosolic leucyl-tRNA synthetase, cause infantile liver failure syndrome 1 (ILFS1). Since its description in 2012, there has been no systematic analysis of the clinical spectrum and genetic findings. METHODS: Individuals with biallelic variants in LARS1 were included through an international, multicenter collaboration including novel and previously published patients. Clinical variables were analyzed and functional studies were performed in patient-derived fibroblasts. RESULTS: Twenty-five individuals from 15 families were ascertained including 12 novel patients with eight previously unreported variants. The most prominent clinical findings are recurrent elevation of liver transaminases up to liver failure and encephalopathic episodes, both triggered by febrile illness. Magnetic resonance image (MRI) changes during an encephalopathic episode can be consistent with metabolic stroke. Furthermore, growth retardation, microcytic anemia, neurodevelopmental delay, muscular hypotonia, and infection-related seizures are prevalent. Aminoacylation activity is significantly decreased in all patient cells studied upon temperature elevation in vitro. CONCLUSION: ILFS1 is characterized by recurrent elevation of liver transaminases up to liver failure in conjunction with abnormalities of growth, blood, nervous system, and musculature. Encephalopathic episodes with seizures can occur independently from liver crises and may present with metabolic stroke.


Assuntos
Falência Hepática , Humanos , Hipotonia Muscular , Mutação , Convulsões
11.
Compr Rev Food Sci Food Saf ; 19(1): 44-63, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-33319522

RESUMO

Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color. Differences in achromatic light scattering between light and dark extremes of meat color are most likely explained by structural attributes within the muscle cell. These differences are proposed to arise from variations in (a) transverse shrinkage of the structural lattice of the myofilaments, myofibrils, and muscles fibers, (b) longitudinal shrinkage of the sarcomere, and (c) different protein composition of the surrounding medium (sarcoplasm and extracellular space). These are discussed at a mechanistic level, in relation to six parameters of the muscle cell: (a) protein surface charge altering the myofilament spacing, (b) protein solubility, (c) sarcoplasmic protein binding to myofilaments and myofibrils, (d) integrity of the cytoskeleton and cell adhesion proteins, (e) sarcomere integrity and myofibrillar proteins, and (f) myosin denaturation and rigor bond modification. New data are presented to support the proposed role of structural elements in muscle causing achromatic light scattering and their contribution to the surface color of meat. In addition, the relationships between lightness and water holding capacity and pH are explored and the economic impact of dark meat for the meat industry is discussed.


Assuntos
Cor , Carne Vermelha/análise , Carne Vermelha/normas , Animais , Bovinos , Heme/química , Proteínas Musculares/química , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/química , Músculo Esquelético/citologia , Pigmentação , Ovinos , Suínos
12.
Hum Mutat ; 40(10): 1731-1748, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31045291

RESUMO

Mutations in either the mitochondrial or nuclear genomes are associated with a diverse group of human disorders characterized by impaired mitochondrial respiration. Within this group, an increasing number of mutations have been identified in nuclear genes involved in mitochondrial RNA metabolism, including ELAC2. The ELAC2 gene codes for the mitochondrial RNase Z, responsible for endonucleolytic cleavage of the 3' ends of mitochondrial pre-tRNAs. Here, we report the identification of 16 novel ELAC2 variants in individuals presenting with mitochondrial respiratory chain deficiency, hypertrophic cardiomyopathy (HCM), and lactic acidosis. We provide evidence for the pathogenicity of the novel missense variants by studying the RNase Z activity in an in vitro system. We also modeled the residues affected by a missense mutation in solved RNase Z structures, providing insight into enzyme structure and function. Finally, we show that primary fibroblasts from the affected individuals have elevated levels of unprocessed mitochondrial RNA precursors. Our study thus broadly confirms the correlation of ELAC2 variants with severe infantile-onset forms of HCM and mitochondrial respiratory chain dysfunction. One rare missense variant associated with the occurrence of prostate cancer (p.Arg781His) impairs the mitochondrial RNase Z activity of ELAC2, suggesting a functional link between tumorigenesis and mitochondrial RNA metabolism.


Assuntos
Cardiomiopatia Hipertrófica/genética , Genes Mitocondriais , Predisposição Genética para Doença , Mutação , Proteínas de Neoplasias/genética , Processamento Pós-Transcricional do RNA , RNA de Transferência/genética , Alelos , Substituição de Aminoácidos , Biomarcadores , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/terapia , Estudos de Coortes , Ativação Enzimática , Feminino , Expressão Gênica , Estudos de Associação Genética , Genótipo , Humanos , Lactente , Cinética , Masculino , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Fenótipo , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-Atividade , Especificidade por Substrato
13.
J Med Genet ; 55(4): 233-239, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29358271

RESUMO

Background Irish Travellers are an endogamous, nomadic, ethnic minority population mostly resident on the island of Ireland with smaller populations in Europe and the USA. High levels of consanguinity result in many rare autosomal recessive disorders. Due to founder effects and endogamy, most recessive disorders are caused by specific homozygous mutations unique to this population. Key clinicians and scientists with experience in managing rare disorders seen in this population have developed a de facto advisory service on differential diagnoses to consider when faced with specific clinical scenarios. Objective(s) To catalogue all known inherited disorders found in the Irish Traveller population. Methods We performed detailed literature and database searches to identify relevant publications and the disease mutations of known genetic disorders found in Irish Travellers. Results We identified 104 genetic disorders: 90 inherited in an autosomal recessive manner; 13 autosomal dominant and one a recurring chromosomal duplication. Conclusion We have collated our experience of inherited disorders found in the Irish Traveller population to make it publically available through this publication to facilitate a targeted genetic approach to diagnostics in this ethnic group.


Assuntos
Doenças Genéticas Inatas/epidemiologia , Doenças Genéticas Inatas/genética , Genética Populacional/classificação , Consanguinidade , Etnicidade/genética , Europa (Continente)/epidemiologia , Doenças Genéticas Inatas/classificação , Humanos , Irlanda/epidemiologia , Grupos Minoritários , Mutação , População Branca
15.
Am J Med Genet A ; 176(5): 1115-1127, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29575569

RESUMO

Short-chain enoyl-CoA hydratase (SCEH or ECHS1) deficiency is a rare inborn error of metabolism caused by biallelic mutations in the gene ECHS1 (OMIM 602292). Clinical presentation includes infantile-onset severe developmental delay, regression, seizures, elevated lactate, and brain MRI abnormalities consistent with Leigh syndrome (LS). Characteristic abnormal biochemical findings are secondary to dysfunction of valine metabolism. We describe four patients from two consanguineous families (one Pakistani and one Irish Traveler), who presented in infancy with LS. Urine organic acid analysis by GC/MS showed increased levels of erythro-2,3-dihydroxy-2-methylbutyrate and 3-methylglutaconate (3-MGC). Increased urine excretion of methacrylyl-CoA and acryloyl-CoA related metabolites analyzed by LC-MS/MS, were suggestive of SCEH deficiency; this was confirmed in patient fibroblasts. Both families were shown to harbor homozygous pathogenic variants in the ECHS1 gene; a c.476A > G (p.Gln159Arg) ECHS1variant in the Pakistani family and a c.538A > G, p.(Thr180Ala) ECHS1 variant in the Irish Traveler family. The c.538A > G, p.(Thr180Ala) ECHS1 variant was postulated to represent a Canadian founder mutation, but we present SNP genotyping data to support Irish ancestry of this variant with a haplotype common to the previously reported Canadian patients and our Irish Traveler family. The presence of detectable erythro-2,3-dihydroxy-2-methylbutyrate is a nonspecific marker on urine organic acid analysis but this finding, together with increased excretion of 3-MGC, elevated plasma lactate, and normal acylcarnitine profile in patients with a Leigh-like presentation should prompt consideration of a diagnosis of SCEH deficiency and genetic analysis of ECHS1. ECHS1 deficiency can be added to the list of conditions with 3-MGA.


Assuntos
Biomarcadores , Enoil-CoA Hidratase/deficiência , Estudos de Associação Genética , Predisposição Genética para Doença , Fenótipo , Sequência de Aminoácidos , Encéfalo/anormalidades , Encéfalo/diagnóstico por imagem , Cromatografia Líquida , Análise Mutacional de DNA , Enoil-CoA Hidratase/genética , Enoil-CoA Hidratase/metabolismo , Ativação Enzimática , Feminino , Estudos de Associação Genética/métodos , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Redes e Vias Metabólicas , Metaboloma , Metabolômica/métodos , Linhagem , Espectrometria de Massas em Tandem , Valina/metabolismo
16.
Appl Environ Microbiol ; 83(20)2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28802267

RESUMO

This study explored transient inactivation of the gene encoding the DNA mismatch repair enzyme MutS as a tool for adaptive evolution of Lactobacillus casei MutS deletion derivatives of L. casei 12A and ATCC 334 were constructed and subjected to a 100-day adaptive evolution process to increase lactic acid resistance at low pH. Wild-type parental strains were also subjected to this treatment. At the end of the process, the ΔmutS lesion was repaired in representative L. casei 12A and ATCC 334 ΔmutS mutant isolates. Growth studies in broth at pH 4.0 (titrated with lactic acid) showed that all four adapted strains grew more rapidly, to higher cell densities, and produced significantly more lactic acid than untreated wild-type cells. However, the adapted ΔmutS derivative mutants showed the greatest increases in growth and lactic acid production. Further characterization of the L. casei 12A-adapted ΔmutS derivative revealed that it had a significantly smaller cell volume, a rougher cell surface, and significantly better survival at pH 2.5 than parental L. casei 12A. Genome sequence analysis confirmed that transient mutS inactivation decreased DNA replication fidelity in both L. casei strains, and it identified genetic changes that might contribute to the lactic acid-resistant phenotypes of adapted cells. Targeted inactivation of three genes that had acquired nonsense mutations in the adapted L. casei 12A ΔmutS mutant derivative showed that NADH dehydrogenase (ndh), phosphate transport ATP-binding protein PstB (pstB), and two-component signal transduction system (TCS) quorum-sensing histidine protein kinase (hpk) genes act in combination to increase lactic acid resistance in L. casei 12A.IMPORTANCE Adaptive evolution has been applied to microorganisms to increase industrially desirable phenotypes, including acid resistance. We developed a method to increase the adaptability of Lactobacillus casei 12A and ATCC 334 through transient inactivation of the DNA mismatch repair enzyme MutS. Here, we show this method was effective in increasing the resistance of L. casei to lactic acid at low pH. Additionally, we identified three genes that contribute to increased acid resistance in L. casei 12A. These results provide valuable insight on methods to enhance an organism's fitness to complex phenotypes through adaptive evolution and targeted gene inactivation.


Assuntos
Proteínas de Bactérias/genética , Ácido Láctico/metabolismo , Lacticaseibacillus casei/genética , Lacticaseibacillus casei/metabolismo , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Proteínas de Bactérias/metabolismo , Evolução Biológica , Concentração de Íons de Hidrogênio , Lacticaseibacillus casei/crescimento & desenvolvimento , Proteína MutS de Ligação de DNA com Erro de Pareamento/metabolismo , Mutação
17.
J Med Genet ; 53(9): 634-41, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27091925

RESUMO

BACKGROUND: Isolated Complex I deficiency is the most common paediatric mitochondrial disease presentation, associated with poor prognosis and high mortality. Complex I comprises 44 structural subunits with at least 10 ancillary proteins; mutations in 29 of these have so far been associated with mitochondrial disease but there are limited genotype-phenotype correlations to guide clinicians to the correct genetic diagnosis. METHODS: Patients were analysed by whole-exome sequencing, targeted capture or candidate gene sequencing. Clinical phenotyping of affected individuals was performed. RESULTS: We identified a cohort of 10 patients from 8 families (7 families are of unrelated Irish ancestry) all of whom have short stature (<9th centile) and similar facial features including a prominent forehead, smooth philtrum and deep-set eyes associated with a recurrent homozygous c.64T>C, p.Trp22Arg NDUFB3 variant. Two sibs presented with primary short stature without obvious metabolic dysfunction. Analysis of skeletal muscle from three patients confirmed a defect in Complex I assembly. CONCLUSIONS: Our report highlights that the long-term prognosis related to the p.Trp22Arg NDUFB3 mutation can be good, even for some patients presenting in acute metabolic crisis with evidence of an isolated Complex I deficiency in muscle. Recognition of the distinctive facial features-particularly when associated with markers of mitochondrial dysfunction and/or Irish ancestry-should suggest screening for the p.Trp22Arg NDUFB3 mutation to establish a genetic diagnosis, circumventing the requirement of muscle biopsy to direct genetic investigations.


Assuntos
Nanismo/genética , Complexo I de Transporte de Elétrons/genética , Mitocôndrias/genética , Doenças Mitocondriais/genética , Mutação/genética , Criança , Pré-Escolar , Exoma/genética , Fácies , Feminino , Estudos de Associação Genética/métodos , Homozigoto , Humanos , Lactente , Masculino , Linhagem , Fenótipo
18.
J Inherit Metab Dis ; 38(6): 1085-92, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25917789

RESUMO

BACKGROUND: Recessive LARS mutations were recently reported to cause a novel syndrome, infantile liver failure syndrome type 1 (ILFS1), in six Irish Travellers. We have since identified four additional patients, including one of Ashkenazi origin, representing the largest ILFS1 cohort to date. Our study aims to define the ILFS1 clinical phenotype to help guide diagnosis and patient management. METHODS: We clinically evaluated and reviewed the medical records of ten ILFS1 patients. Clinical features, histopathology and natural histories were compared and patient management strategies reviewed. RESULTS: Early failure to thrive, recurrent liver dysfunction, anemia, hypoalbuminemia and seizures were present in all patients. Most patients (90 %) had developmental delay. Encephalopathic episodes triggered by febrile illness have occurred in 80 % and were fatal in two children. Two patients are currently >28 years old and clinically well. Leucine supplementation had no appreciable impact on patient well-being. However, we suggest that the traditional management of reducing/stopping protein intake in patients with metabolic hepatopathies may not be appropriate for ILFS1. We currently recommend ensuring sufficient natural protein intake when unwell. CONCLUSIONS: We report the first non-Irish ILFS1 patient, suggesting ILFS1 may be more extensive than anticipated. Low birth weight, early failure to thrive, anemia and hypoalbuminemia are amongst the first presenting features, with liver dysfunction before age 1. Episodic hepatic dysfunction is typically triggered by febrile illness, and becomes less severe with increasing age. While difficult to anticipate, two patients are currently >28 years old, suggesting that survival beyond childhood may be associated with a favourable long-term prognosis.


Assuntos
Anemia/patologia , Insuficiência de Crescimento/genética , Falência Hepática/genética , RNA de Transferência Aminoácido-Específico/genética , Convulsões/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Genes Recessivos , Humanos , Hipoalbuminemia , Lactente , Irlanda , Imageamento por Ressonância Magnética , Masculino , Mutação , Fenótipo , Prognóstico , Insuficiência Renal/fisiopatologia , Adulto Jovem
20.
Br J Educ Psychol ; 83(Pt 1): 57-75, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23369175

RESUMO

BACKGROUND: In this paper, we focused on mixing in educational settings between members of Catholic and Protestant ethnoreligious groups in Northern Ireland. AIMS: In Study 1, we examined whether opportunities for contact at home and at university were associated with greater actual out-group friendships, and whether this friendship was associated with a reduction in prejudice. We also assessed whether the impact of out-group friendships at university was moderated by experience of out-group friendships outside university, such that the prejudice-reducing effect of university friendships was stronger for those with fewer friendships at home. In Study 2, we assessed opportunities for contact and actual out-group friendships at prior stages of the educational system and their relationship with prejudice. Sample(s). In both studies, our participants were students at universities in Northern Ireland (Study 1 N= 304 and Study 2 N= 157). METHODS: We analysed the data using multiple regression and structural equation modelling. RESULTS: First, opportunities for contact were positively associated with self-reported out-group friendships in all domains and stages of the educational system. Second, having more out-group friends was associated with reduced prejudice. Finally, the relationship between out-group friendships and current levels of prejudice was moderated by prior levels of out-group friendships (at home in Study 1; and at secondary and primary school in Study 2). CONCLUSIONS: Contact, in the form of out-group friendships, was more powerful when it was a novel feature in a person's life. We discuss these findings in terms of the impact of mixing in educational contexts, especially in Northern Ireland, and outline suggestions for future research.


Assuntos
Amigos/psicologia , Processos Grupais , Preconceito/psicologia , Distância Psicológica , Meio Social , Estudantes/psicologia , Adulto , Catolicismo/psicologia , Feminino , Humanos , Masculino , Irlanda do Norte , Protestantismo/psicologia , Instituições Acadêmicas , Identificação Social , Estudantes/estatística & dados numéricos , Universidades , Adulto Jovem
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