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1.
Genome Res ; 34(4): 606-619, 2024 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-38589251

RESUMEN

Genomes have a highly organized architecture (nonrandom organization of functional and nonfunctional genetic elements within chromosomes) that is essential for many biological functions, particularly gene expression and reproduction. Despite the need to conserve genome architecture, a high level of structural variation has been observed within species. As species separate and diverge, genome architecture also diverges, becoming increasingly poorly conserved as divergence time increases. However, within plant genomes, the processes of genome architecture divergence are not well described. Here we use long-read sequencing and de novo assembly of 33 phylogenetically diverse, wild and naturally evolving Eucalyptus species, covering 1-50 million years of diverging genome evolution to measure genome architectural conservation and describe architectural divergence. The investigation of these genomes revealed that following lineage divergence, genome architecture is highly fragmented by rearrangements. As genomes continue to diverge, the accumulation of mutations and the subsequent divergence beyond recognition of rearrangements become the primary driver of genome divergence. The loss of syntenic regions also contribute to genome divergence but at a slower pace than that of rearrangements. We hypothesize that duplications and translocations are potentially the greatest contributors to Eucalyptus genome divergence.


Asunto(s)
Eucalyptus , Evolución Molecular , Genoma de Planta , Eucalyptus/genética , Sintenía , Reordenamiento Génico , Filogenia , Cromosomas de las Plantas/genética , Variación Genética
2.
BMC Genomics ; 25(1): 640, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38937661

RESUMEN

BACKGROUND: Drought adaptation is critical to many tree species persisting under climate change, however our knowledge of the genetic basis for trees to adapt to drought is limited. This knowledge gap impedes our fundamental understanding of drought response and application to forest production and conservation. To improve our understanding of the genomic determinants, architecture, and trait constraints, we assembled a reference genome and detected ~ 6.5 M variants in 432 phenotyped individuals for the foundational tree Corymbia calophylla. RESULTS: We found 273 genomic variants determining traits with moderate heritability (h2SNP = 0.26-0.64). Significant variants were predominantly in gene regulatory elements distributed among several haplotype blocks across all chromosomes. Furthermore, traits were constrained by frequent epistatic and pleiotropic interactions. CONCLUSIONS: Our results on the genetic basis for drought traits in Corymbia calophylla have several implications for the ability to adapt to climate change: (1) drought related traits are controlled by complex genomic architectures with large haplotypes, epistatic, and pleiotropic interactions; (2) the most significant variants determining drought related traits occurred in regulatory regions; and (3) models incorporating epistatic interactions increase trait predictions. Our findings indicate that despite moderate heritability drought traits are likely constrained by complex genomic architecture potentially limiting trees response to climate change.


Asunto(s)
Sequías , Epistasis Genética , Genómica , Genoma de Planta , Haplotipos , Sitios de Carácter Cuantitativo , Fenotipo , Polimorfismo de Nucleótido Simple
3.
Mult Scler ; 30(4-5): 505-515, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38419027

RESUMEN

BACKGROUND: Performing routine brain magnetic resonance imaging (MRI) is widely accepted as the standard of care for disease monitoring in multiple sclerosis (MS), but the utility of performing routine spinal cord (SC) MRI for this purpose is still debatable. OBJECTIVE: This study aimed to measure the frequency of new isolated cervical spinal cord lesions (CSLs) in people with MS (pwMS) undergoing routine brain and cervical SC-MRI for disease monitoring and determine the factors associated with the development of new CSLs and their prognostic value. METHODS: We retrospectively identified 1576 pwMS who underwent follow-up 3T brain and cervical SC-MRI over a 9-month period. MRI was reviewed for the presence of new brain lesions (BLs) and CSLs. Clinical records were reviewed for interval relapses between sequential scans and subsequent clinical relapse and disability worsening after the follow-up MRI. RESULTS: In 1285 pwMS (median interval: 13-14 months) who were clinically stable with respect to relapses, 73 (5.7%) had new CSLs, of which 49 (3.8%) had concomitant new BLs and 24 (1.9%) had new isolated CSLs only. New asymptomatic CSLs were associated with ⩾ 3 prior relapses (p = 0.04), no disease-modifying therapy (DMT) use (p = 0.048), and ⩾ 3 new BLs (p < 0.001); ⩾ 3 new BLs (OR: 7.11, 95% CI: 4.3-11.7, p < 0.001) remained independently associated with new CSLs on multivariable analysis. Having new asymptomatic CSLs was not independently associated with subsequent relapse or disability worsening after the follow-up MRI (median follow-up time of 26 months). CONCLUSION: Routine brain and cervical SC-MRI detected new isolated CSLs in only < 2% of clinically stable pwMS. Developing new asymptomatic CSLs was associated with concomitant new BLs and did not confer an independent increased risk of relapse or disability worsening. Performing SC-MRI may not be warranted for routine monitoring in most pwMS, and performing only brain MRI may be sufficient to capture the vast majority of clinically silent disease activity.


Asunto(s)
Médula Cervical , Esclerosis Múltiple , Enfermedades de la Médula Espinal , Humanos , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/patología , Médula Cervical/diagnóstico por imagen , Médula Cervical/patología , Estudios Retrospectivos , Progresión de la Enfermedad , Médula Espinal/diagnóstico por imagen , Médula Espinal/patología , Imagen por Resonancia Magnética/métodos , Enfermedades de la Médula Espinal/patología , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Recurrencia
4.
J Zoo Wildl Med ; 55(1): 155-163, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38453498

RESUMEN

Meerkats (Suricata suricatta) housed at two accredited zoological institutions in the United States were evaluated via echocardiography, thoracic radiography, and blood biomarkers-taurine and feline N-terminal pro-B-type natriuretic peptide-to determine the prevalence and severity of dilated cardiomyopathy (DCM) in both populations. In total, 24 meerkats were evaluated and 7 were diagnosed with DCM based on the following parameters: left ventricular internal diameter at end diastole > 1.30 cm, left ventricular internal diameter at end systole > 1.10 cm, and a fractional shortening of <18%. Echocardiographic parameters were identified and reported for normal and affected meerkats, whereas thoracic radiographs were not useful for screening for DCM. Meerkats with DCM were treated with pimobendan and/or benazepril and furosemide if indicated. Seven meerkats died during the study period, with the majority exhibiting myocardial fibrosis. Of the blood parameters tested, elevated taurine levels were associated with DCM. Further research is necessary to characterize the etiology of DCM in meerkats.


Asunto(s)
Cardiomiopatía Dilatada , Enfermedades de los Gatos , Herpestidae , Humanos , Gatos , Animales , Cardiomiopatía Dilatada/veterinaria , Ecocardiografía/veterinaria , Radiografía , Taurina
5.
Neurobiol Dis ; 180: 106082, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36925053

RESUMEN

Humans are thought to be more susceptible to neurodegeneration than equivalently-aged primates. It is not known whether this vulnerability is specific to anatomically-modern humans or shared with other hominids. The contribution of introgressed Neanderthal DNA to neurodegenerative disorders remains uncertain. It is also unclear how common variants associated with neurodegenerative disease risk are maintained by natural selection in the population despite their deleterious effects. In this study, we aimed to quantify the genome-wide contribution of Neanderthal introgression and positive selection to the heritability of complex neurodegenerative disorders to address these questions. We used stratified-linkage disequilibrium score regression to investigate the relationship between five SNP-based signatures of natural selection, reflecting different timepoints of evolution, and genome-wide associated variants of the three most prevalent neurodegenerative disorders: Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease. We found no evidence for enrichment of positively-selected SNPs in the heritability of Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease, suggesting that common deleterious disease variants are unlikely to be maintained by positive selection. There was no enrichment of Neanderthal introgression in the SNP-heritability of these disorders, suggesting that Neanderthal admixture is unlikely to have contributed to disease risk. These findings provide insight into the origins of neurodegenerative disorders within the evolution of Homo sapiens and addresses a long-standing debate, showing that Neanderthal admixture is unlikely to have contributed to common genetic risk of neurodegeneration in anatomically-modern humans.


Asunto(s)
Enfermedad de Alzheimer , Esclerosis Amiotrófica Lateral , Hombre de Neandertal , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Animales , Humanos , Hombre de Neandertal/genética , Enfermedades Neurodegenerativas/genética , Selección Genética
6.
J Virol ; 96(1): e0096421, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-34668775

RESUMEN

A comprehensive analysis and characterization of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection model that mimics non-severe and severe coronavirus disease 2019 (COVID-19) in humans is warranted for understating the virus and developing preventive and therapeutic agents. Here, we characterized the K18-hACE2 mouse model expressing human (h)ACE2 in mice, controlled by the human keratin 18 (K18) promoter, in the epithelia, including airway epithelial cells where SARS-CoV-2 infections typically start. We found that intranasal inoculation with higher viral doses (2 × 103 and 2 × 104 PFU) of SARS-CoV-2 caused lethality of all mice and severe damage of various organs, including lung, liver, and kidney, while lower doses (2 × 101 and 2 × 102 PFU) led to less severe tissue damage and some mice recovered from the infection. In this hACE2 mouse model, SARS-CoV-2 infection damaged multiple tissues, with a dose-dependent effect in most tissues. Similar damage was observed in postmortem samples from COVID-19 patients. Finally, the mice that recovered from infection with a low dose of virus survived rechallenge with a high dose of virus. Compared to other existing models, the K18-hACE2 model seems to be the most sensitive COVID-19 model reported to date. Our work expands the information available about this model to include analysis of multiple infectious doses and various tissues with comparison to human postmortem samples from COVID-19 patients. In conclusion, the K18-hACE2 mouse model recapitulates both severe and non-severe COVID-19 in humans being dose-dependent and can provide insight into disease progression and the efficacy of therapeutics for preventing or treating COVID-19. IMPORTANCE The pandemic of coronavirus disease 2019 (COVID-19) has reached nearly 240 million cases, caused nearly 5 million deaths worldwide as of October 2021, and has raised an urgent need for the development of novel drugs and therapeutics to prevent the spread and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To achieve this goal, an animal model that recapitulates the features of human COVID-19 disease progress and pathogenesis is greatly needed. In this study, we have comprehensively characterized a mouse model of SARS-CoV-2 infection using K18-hACE2 transgenic mice. We infected the mice with low and high doses of SARS-CoV-2 to study the pathogenesis and survival in response to different infection patterns. Moreover, we compared the pathogenesis of the K18-hACE2 transgenic mice with that of the COVID-19 patients to show that this model could be a useful tool for the development of antiviral drugs and therapeutics.


Asunto(s)
COVID-19/patología , Modelos Animales de Enfermedad , SARS-CoV-2/patogenicidad , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , COVID-19/inmunología , COVID-19/mortalidad , COVID-19/virología , Humanos , Sueros Inmunes/inmunología , Queratina-18/genética , Ratones , Ratones Transgénicos , Regiones Promotoras Genéticas , Reinfección/inmunología , Reinfección/mortalidad , Reinfección/patología , Reinfección/virología , SARS-CoV-2/inmunología , Proteínas Virales/genética , Proteínas Virales/metabolismo
7.
Mol Ecol ; 32(6): 1271-1287, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35810343

RESUMEN

Synteny, the ordering of sequences within homologous chromosomes, must be maintained within the genomes of sexually reproducing species for the sharing of alleles and production of viable, reproducing offspring. However, when the genomes of closely related species are compared, a loss of synteny is often observed. Unequal homologous recombination is the primary mechanism behind synteny loss, occurring more often in transposon rich regions, and resulting in the formation of chromosomal rearrangements. To examine patterns of synteny among three closely related, interbreeding, and wild Eucalyptus species, we assembled their genomes using long-read DNA sequencing and de novo assembly. We identify syntenic and rearranged regions between these genomes and estimate that ~48% of our genomes remain syntenic while ~36% is rearranged. We observed that rearrangements highly fragment microsynteny. Our results suggest that synteny between these species is primarily lost through small-scale rearrangements, not through sequence loss, gain, or sequence divergence. Further examination of identified rearrangements suggests that rearrangements may be altering the phenotypes of Eucalyptus species. Our study also underscores that the use of single reference genomes in genomic variation studies could lead to reference bias, especially given the scale at which we show potentially adaptive loci have highly diverged, deleted, duplicated and/or rearranged. This study provides an unbiased framework to look at potential speciation and adaptive loci among a rapidly radiating foundation species of woodland trees that are free from selective breeding seen in most crop species.


Asunto(s)
Eucalyptus , Eucalyptus/genética , Genoma , Sintenía/genética , Cromosomas , Análisis de Secuencia de ADN/métodos
8.
Br J Dermatol ; 189(6): 674-684, 2023 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-37722926

RESUMEN

BACKGROUND: Conventional systemic drugs are used to treat children and young people (CYP) with severe atopic dermatitis (AD) worldwide, but no robust randomized controlled trial (RCT) evidence exists regarding their efficacy and safety in this population. While novel therapies have expanded therapeutic options, their high cost means traditional agents remain important, especially in lower-resource settings. OBJECTIVES: To compare the safety and efficacy of ciclosporin (CyA) with methotrexate (MTX) in CYP with severe AD in the TREatment of severe Atopic Eczema Trial (TREAT) trial. METHODS: We conducted a parallel group assessor-blinded RCT in 13 UK and Irish centres. Eligible participants aged 2-16 years and unresponsive to potent topical treatment were randomized to either oral CyA (4 mg kg-1 daily) or MTX (0.4 mg kg-1 weekly) for 36 weeks and followed-up for 24 weeks. Co-primary outcomes were change from baseline to 12 weeks in Objective Severity Scoring of Atopic Dermatitis (o-SCORAD) and time to first significant flare (relapse) after treatment cessation. Secondary outcomes included change in quality of life (QoL) from baseline to 60 weeks; number of participant-reported flares following treatment cessation; proportion of participants achieving ≥ 50% improvement in Eczema Area and Severity Index (EASI 50) and ≥ 75% improvement in EASI (EASI 75); and stratification of outcomes by filaggrin status. RESULTS: In total, 103 participants were randomized (May 2016-February 2019): 52 to CyA and 51 to MTX. CyA showed greater improvement in disease severity by 12 weeks [mean difference in o-SCORAD -5.69, 97.5% confidence interval (CI) -10.81 to -0.57 (P = 0.01)]. More participants achieved ≥ 50% improvement in o-SCORAD (o-SCORAD 50) at 12 weeks in the CyA arm vs. the MTX arm [odds ratio (OR) 2.60, 95% CI 1.23-5.49; P = 0.01]. By 60 weeks MTX was superior (OR 0.33, 95% CI 0.13-0.85; P = 0.02), a trend also seen for ≥ 75% improvement in o-SCORAD (o-SCORAD 75), EASI 50 and EASI 75. Participant-reported flares post-treatment were higher in the CyA arm (OR 3.22, 95% CI 0.42-6.01; P = 0.02). QoL improved with both treatments and was sustained after treatment cessation. Filaggrin status did not affect outcomes. The frequency of adverse events (AEs) was comparable between both treatments. Five (10%) participants on CyA and seven (14%) on MTX experienced a serious AE. CONCLUSIONS: Both CyA and MTX proved effective in CYP with severe AD over 36 weeks. Participants who received CyA showed a more rapid response to treatment, while MTX induced more sustained disease control after discontinuation.


Asunto(s)
Ciclosporina , Dermatitis Atópica , Niño , Humanos , Adolescente , Ciclosporina/efectos adversos , Metotrexato/efectos adversos , Dermatitis Atópica/tratamiento farmacológico , Proteínas Filagrina , Oportunidad Relativa , Resultado del Tratamiento , Índice de Severidad de la Enfermedad , Método Doble Ciego
9.
Epidemiol Infect ; 151: e30, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36786292

RESUMEN

The COVID-19 pandemic has presented a unique opportunity to understand how real-time pathogen genomics can be used for large-scale outbreak investigations. On 12 August 2021, the Australian Capital Territory (ACT) detected an incursion of the SARS-CoV-2 Delta (B.1.617.2) variant. Prior to this date, SARS-CoV-2 had been eliminated locally since 7 July 2020. Several public health interventions were rapidly implemented in response to the incursion, including a territory-wide lockdown and comprehensive contact tracing. The ACT has not previously used pathogen genomics at a population level in an outbreak response; therefore, this incursion also presented an opportunity to investigate the utility of genomic sequencing to support contact tracing efforts in the ACT. Sequencing of >75% of the 1793 laboratory-confirmed cases during the 3 months following the initial notification identified at least 13 independent incursions with onwards spread in the community. Stratification of cases by genomic cluster revealed that distinct cohorts were affected by the different incursions. Two incursions resulted in most of the community transmission during the study period, with persistent transmission in vulnerable sections of the community. Ultimately, both major incursions were successfully mitigated through public health interventions, including COVID-19 vaccines. The high rates of SARS-CoV-2 sequencing in the ACT and the relatively small population size facilitated detailed investigations of the patterns of virus transmission, revealing insights beyond those gathered from traditional contact tracing alone. Genomic sequencing was critical to disentangling complex transmission chains to target interventions appropriately.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Salud Pública , Territorio de la Capital Australiana , Vacunas contra la COVID-19 , Pandemias , Control de Enfermedades Transmisibles , Australia
10.
Health Promot Pract ; 24(3): 404-405, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37122281

RESUMEN

Social media has kept us connected in many ways but for Black adults, it can be a harrowing reminder of the treatment of Black bodies. This poem was crafted from focus group data on a study of the effects of vicarious racism on the mental health of Black adults in the wake of George Floyd's death in 2020. This poem uses elements of found poetry and incorporates texts from the narrative (re)telling of Black adults' emotional impact of seeing racially and police-involved killings of Black men. Participants expressed feelings of anger, powerlessness, and sadness and how watching these videos has led to avoidance behavior for the sake of coping. In this poem titled "He Looks like My Father," the participant shares a memory of the last video that they watched on social media in 2014 and why they continue to avoid this type of content. It's traumatizing. It is important to fully reflect on these stories as Black Americans struggle with staying informed and preserving their mental health while being inundated by a continuous feedback loop of Black death. The elements of this poem incorporate repetition and the bolded words are verbatim text from the participant transcript. I acknowledge that my positionality being a Black American woman, with a Black father, and having shared the embodied experience of witnessing Black death via social media influenced the meaning of this poem. As we continue to see a focus on naming racism as a public health threat, this form of vicarious racism is salient and should be explored as health professionals dig deeper into understanding the many ways racism permeates the lives of Black, is a daily stressor, and is a social determinant of mental health equity. These are the narratives from muted lips to unveil your eyes. To view the original version of this poem, see the supplemental material section of this article online.


Asunto(s)
Racismo , Adulto , Femenino , Humanos , Masculino , Negro o Afroamericano , Emociones , Padre , Poesía como Asunto
11.
Cell Mol Life Sci ; 78(1): 249-270, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32170339

RESUMEN

eIF4E plays key roles in protein synthesis and tumorigenesis. It is phosphorylated by the kinases MNK1 and MNK2. Binding of MNKs to eIF4G enhances their ability to phosphorylate eIF4E. Here, we show that mTORC1, a key regulator of mRNA translation and oncogenesis, directly phosphorylates MNK2 on Ser74. This suppresses MNK2 activity and impairs binding of MNK2 to eIF4G. These effects provide a novel mechanism by which mTORC1 signaling impairs the function of MNK2 and thereby decreases eIF4E phosphorylation. MNK2[S74A] knock-in cells show enhanced phosphorylation of eIF4E and S6K1 (i.e., increased mTORC1 signaling), enlarged cell size, and increased invasive and transformative capacities. MNK2[Ser74] phosphorylation was inversely correlated with disease progression in human prostate tumors. MNK inhibition exerted anti-proliferative effects in prostate cancer cells in vitro. These findings define a novel feedback loop whereby mTORC1 represses MNK2 activity and oncogenic signaling through eIF4E phosphorylation, allowing reciprocal regulation of these two oncogenic pathways.


Asunto(s)
Factor 4E Eucariótico de Iniciación/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Factor 4E Eucariótico de Iniciación/antagonistas & inhibidores , Humanos , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Morfolinas/farmacología , Mutagénesis Sitio-Dirigida , Fosforilación/efectos de los fármacos , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Unión Proteica , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal/efectos de los fármacos , Proteína 2 del Complejo de la Esclerosis Tuberosa/genética , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismo
12.
BMC Geriatr ; 22(1): 538, 2022 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-35768788

RESUMEN

BACKGROUND: There is a lack of of cross-sectional research that has investigated muscle morphology, function, and functional capability in all age-bands of healthy adults. The primary aim of this study was to evaluate age-related differences in indices of vastus lateralis (VL) muscle morphology, function and functional capability in a sample of healthy males and females aged 18-70yrs. Secondary aims were to evaluate relationships between age and VL muscle morphology and function and functional capability. METHODS: B mode Ultrasonography and Tensiomyography were used to measure VL muscle thickness, pennation angle, fascicle length, and contractile properties in 274 healthy adults aged 18-70yrs. Measurements of grip strength and functional capability (1-min chair rise test) were also taken. Data analysis included descriptive statistics, correlations, one-way ANOVAs, and multiple regressions. RESULTS: Negative correlations were found between age and muscle thickness (rs = -.56), pennation angle (rs = -.50), fascicle length (rs = -.30), maximal displacement (rs = -.24), grip strength (rs = -.27) and the 1-min chair rise test (rs = -.32). Positive correlations were observed between age and the echo intensity of the muscle (rs = .40) and total contraction time (rs = .20). Differences in the indices of muscle health were noticeable between the 18-29 age band and the 50-59 and 60-70 age bands (p < 0.05). The interaction of age and level of physical activity predicted changes in the variables (r2 = .04-.32). CONCLUSION: Age-related differences in muscle health are noticeable at 50 years of age, and age-related differences are larger in females compared to males. It was suggested that the thickness of the VL changed the most with age across the adult lifespan and that physical activity likely acts to abate detrimental change.


Asunto(s)
Músculo Esquelético , Músculo Cuádriceps , Estudios Transversales , Femenino , Fuerza de la Mano , Humanos , Extremidad Inferior , Masculino , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Músculo Cuádriceps/diagnóstico por imagen , Músculo Cuádriceps/fisiología , Ultrasonografía
13.
BMC Biol ; 19(1): 203, 2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-34526021

RESUMEN

BACKGROUND: Silencing of transposable elements (TEs) is essential for maintaining genome stability. Plants use small RNAs (sRNAs) to direct DNA methylation to TEs (RNA-directed DNA methylation; RdDM). Similar mechanisms of epigenetic silencing in the fungal kingdom have remained elusive. RESULTS: We use sRNA sequencing and methylation data to gain insight into epigenetics in the dikaryotic fungus Puccinia graminis f. sp. tritici (Pgt), which causes the devastating stem rust disease on wheat. We use Hi-C data to define the Pgt centromeres and show that they are repeat-rich regions (~250 kb) that are highly diverse in sequence between haplotypes and, like in plants, are enriched for young TEs. DNA cytosine methylation is particularly active at centromeres but also associated with genome-wide control of young TE insertions. Strikingly, over 90% of Pgt sRNAs and several RNAi genes are differentially expressed during infection. Pgt induces waves of functionally diversified sRNAs during infection. The early wave sRNAs are predominantly 21 nts with a 5' uracil derived from genes. In contrast, the late wave sRNAs are mainly 22-nt sRNAs with a 5' adenine and are strongly induced from centromeric regions. TEs that overlap with late wave sRNAs are more likely to be methylated, both inside and outside the centromeres, and methylated TEs exhibit a silencing effect on nearby genes. CONCLUSIONS: We conclude that rust fungi use an epigenetic silencing pathway that might have similarity with RdDM in plants. The Pgt RNAi machinery and sRNAs are under tight temporal control throughout infection and might ensure genome stability during sporulation.


Asunto(s)
Basidiomycota , Metilación de ADN , Puccinia , Basidiomycota/genética , Centrómero , Metilación de ADN/genética , Elementos Transponibles de ADN , Inestabilidad Genómica , Humanos , Enfermedades de las Plantas/genética , Puccinia/patogenicidad , ARN
14.
Int J Mol Sci ; 23(22)2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36430598

RESUMEN

Spring cold stress (SCS) compromises the reproductive growth of wheat, being a major constraint in achieving high grain yield and quality in winter wheat. To sustain wheat productivity in SCS conditions, breeding cultivars conferring cold tolerance is key. In this review, we examine how grain setting and quality traits are affected by SCS, which may occur at the pre-anthesis stage. We have investigated the physiological and molecular mechanisms involved in floret and spikelet SCS tolerance. It includes the protective enzymes scavenging reactive oxygen species (ROS), hormonal adjustment, and carbohydrate metabolism. Lastly, we explored quantitative trait loci (QTLs) that regulate SCS for identifying candidate genes for breeding. The existing cultivars for SCS tolerance were primarily bred on agronomic and morphophysiological traits and lacked in molecular investigations. Therefore, breeding novel wheat cultivars based on QTLs and associated genes underlying the fundamental resistance mechanism is urgently needed to sustain grain setting and quality under SCS.


Asunto(s)
Respuesta al Choque por Frío , Triticum , Respuesta al Choque por Frío/genética , Barajamiento de ADN , Fitomejoramiento , Grano Comestible/genética
15.
Acad Psychiatry ; 46(6): 746-749, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35292928

RESUMEN

OBJECTIVE: The purpose of this qualitative study was to investigate the lived experiences, beliefs, attitudes, and needs of psychiatry residents learning cognitive behavioral therapy (CBT). METHOD: Eight general psychiatry residents beginning their outpatient psychotherapy training in July 2020, answered open-ended questions about their experiences learning CBT in October 2020. The residents learned CBT through didactics, role-play, observation, video review, and individual and group supervision. Participants were asked to describe their experiences broadly, reflect on the simple and challenging aspects of learning, identify the most and least helpful learning modalities, and share thoughts or personal reflections activated through their journey. Written data were analyzed using Colaizzi's phenomenological methodology, including the extraction of significance statements and collapsing of meaning statements into key thematic clusters. Verification strategies were used to ensure the trustworthiness and credibility of data analysis. RESULTS: Participants found various learning modalities effective, most notably individual and group supervision. While rapport building and mood checks were least challenging, many found adhering to structure or implementation of advanced techniques to be the more arduous parts of learning. Patient progress tended to stimulate resident engagement, whereas incomplete action plans or lack of observable treatment gains led to some automatic negative thoughts. Many participants applied CBT techniques to themselves to address their own automatic thoughts, biases, or behavioral patterns. CONCLUSIONS: The results of this study offer valuable insight about learners' experiences of becoming a therapist that could help normalize residents' experiences and help educators guide residents through the learning process.


Asunto(s)
Terapia Cognitivo-Conductual , Internado y Residencia , Psiquiatría , Humanos , Psiquiatría/educación , Investigación Cualitativa , Aprendizaje , Terapia Cognitivo-Conductual/educación
16.
Mult Scler ; 27(7): 1027-1036, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32779522

RESUMEN

BACKGROUND: Multiple sclerosis (MS) incidence is rising in traditionally low-burden regions, including the Middle East and North Africa (MENA). OBJECTIVES: Our objective was to evaluate disease characteristics in MS patients of MENA descent (MENA-MS). METHODS: MENA-MS patients and age- and sex-matched MS patients of European descent (EUR-MS) were identified through the MS Clinic Registry of St. Michael's Hospital in Toronto, Canada. Disease activity and severity were evaluated by the annualized relapse rate (ARR), magnetic resonance imaging (MRI) activity, change in the Expanded Disability Status Scale (EDSS), progression index (PI), and MS Severity Score (MSSS). RESULTS: All MS patients within the registry identified to be of MENA origin (n = 192), and age- and sex-matched EUR-MS patients were included. Mean age was 42.9 years, 67% female. A total of 25% and 24% of EUR-MS and MENA-MS had progressive disease, with similar mean disease durations (11.5 and 11.4 years, respectively). Clinical and radiological disease activity (ARR, proportion with new/enlarging MRI lesions) was similar. MENA-MS showed greater disability progression over time (EDSS change = 0.24 vs. 0.06, p = 0.01), a higher MSSS (3.12 vs. 2.67, p = 0.04), and higher PI (0.34 vs. 0.27, p = 0.07). CONCLUSION: MENA-MS patients demonstrate higher disease severity compared to EUR-MS patients, despite having similar inflammatory measures of disease activity, with disability progression in the absence of relapses. These observations illustrate the importance of the intersections of environmental, socioeconomic, and genetic determinants in optimizing individualized MS care.


Asunto(s)
Esclerosis Múltiple , Adulto , Progresión de la Enfermedad , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Esclerosis Múltiple/diagnóstico por imagen , Ontario/epidemiología , Recurrencia , Índice de Severidad de la Enfermedad
17.
Health Promot Pract ; 22(6): 761-763, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34414817

RESUMEN

Black/African American populations in the United States are disproportionately affected by the COVID-19 pandemic, and there is evidence suggesting that vaccine hesitancy is a concern among this group. As an alternative to the primary prevention method of vaccination, the tertiary method of disclosing one's COVID-19 status after contracting the virus is of utmost importance in reducing the spread of the virus. Recommendations to inform disclosure decisions based on an HIV disclosure model can be applied to COVID-19-positive Black populations in clinical and community settings to reduce the spread of the virus among this population.


Asunto(s)
COVID-19 , Infecciones por VIH , Vacunas contra la COVID-19 , Revelación , Infecciones por VIH/prevención & control , Humanos , Pandemias , SARS-CoV-2 , Estados Unidos
18.
Mol Plant Microbe Interact ; 33(5): 724-726, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32096690

RESUMEN

Macrophomina phaseolina is a soil-borne phytopathogenic fungus that causes charcoal rot in several plant species, including sorghum. We constructed a draft genome of M. phaseolina isolate BRIP 70780a from sorghum, using long-read native DNA from MinION sequencing, which was error-corrected using short-read Illumina MiSeq reads. The draft genome, consisting of 22 contigs with an N50 of 4,257,441 bp, 99.3% complete benchmarking universal single-copy orthologs, and 14,471 genes, is a valuable resource to aid future studies in population genomics and molecular diagnostic marker development for rapid detection of the pathogen.


Asunto(s)
Ascomicetos/genética , Genoma Fúngico , Enfermedades de las Plantas/microbiología , Sorghum/microbiología , Grano Comestible/microbiología
19.
Hum Mol Genet ; 27(7): 1276-1289, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29415125

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a fatal degenerative motor neuron disorder of which the progression is influenced by several disease-modifying factors. Here, we investigated ELP3, a subunit of the elongator complex that modifies tRNA wobble uridines, as one of such ALS disease modifiers. ELP3 attenuated the axonopathy of a mutant SOD1, as well as of a mutant C9orf72 ALS zebrafish model. Furthermore, the expression of ELP3 in the SOD1G93A mouse extended the survival and attenuated the denervation in this model. Depletion of ELP3 in vitro reduced the modified tRNA wobble uridine mcm5s2U and increased abundance of insoluble mutant SOD1, which was reverted by exogenous ELP3 expression. Interestingly, the expression of ELP3 in the motor cortex of ALS patients was reduced and correlated with mcm5s2U levels. Our results demonstrate that ELP3 is a modifier of ALS and suggest a link between tRNA modification and neurodegeneration.


Asunto(s)
Esclerosis Amiotrófica Lateral , Histona Acetiltransferasas , Corteza Motora/metabolismo , Proteínas del Tejido Nervioso , ARN de Transferencia , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Animales , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Procesamiento Postranscripcional del ARN , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismo , Pez Cebra
20.
N Engl J Med ; 376(17): 1637-1646, 2017 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-28445659

RESUMEN

BACKGROUND: Adalimumab, a fully human anti-tumor necrosis factor α monoclonal antibody, is effective in the treatment of juvenile idiopathic arthritis (JIA). We tested the efficacy of adalimumab in the treatment of JIA-associated uveitis. METHODS: In this multicenter, double-blind, randomized, placebo-controlled trial, we assessed the efficacy and safety of adalimumab in children and adolescents 2 years of age or older who had active JIA-associated uveitis. Patients who were taking a stable dose of methotrexate were randomly assigned in a 2:1 ratio to receive either adalimumab (at a dose of 20 mg or 40 mg, according to body weight) or placebo, administered subcutaneously every 2 weeks. Patients continued the trial regimen until treatment failure or until 18 months had elapsed. They were followed for up to 2 years after randomization. The primary end point was the time to treatment failure, defined according to a multicomponent intraocular inflammation score that was based on the Standardization of Uveitis Nomenclature criteria. RESULTS: The prespecified stopping criteria were met after the enrollment of 90 of 114 patients. We observed 16 treatment failures in 60 patients (27%) in the adalimumab group versus 18 treatment failures in 30 patients (60%) in the placebo group (hazard ratio, 0.25; 95% confidence interval [CI], 0.12 to 0.49; P<0.0001 [the prespecified stopping boundary]). Adverse events were reported more frequently in patients receiving adalimumab than in those receiving placebo (10.07 events per patient-year [95% CI, 9.26 to 10.89] vs. 6.51 events per patient-year [95% CI, 5.26 to 7.77]), as were serious adverse events (0.29 events per patient-year [95% CI, 0.15 to 0.43] vs. 0.19 events per patient-year [95% CI, 0.00 to 0.40]). CONCLUSIONS: Adalimumab therapy controlled inflammation and was associated with a lower rate of treatment failure than placebo among children and adolescents with active JIA-associated uveitis who were taking a stable dose of methotrexate. Patients who received adalimumab had a much higher incidence of adverse events and serious adverse events than those who received placebo. (Funded by the NIHR Health Technology Assessment Programme and Arthritis Research UK; SYCAMORE EudraCT number, 2010-021141-41 .).


Asunto(s)
Adalimumab/uso terapéutico , Antiinflamatorios/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Juvenil/complicaciones , Metotrexato/uso terapéutico , Uveítis/tratamiento farmacológico , Adalimumab/efectos adversos , Adolescente , Antiinflamatorios/efectos adversos , Artritis Juvenil/tratamiento farmacológico , Niño , Preescolar , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Análisis de Intención de Tratar , Masculino , Factores de Tiempo , Uveítis/etiología
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