RESUMEN
INTRODUCTION/AIMS: Self-efficacy reflects a person's perceptions of their capabilities for specific tasks and influences motivation and performance. The Unidimensional Self-Efficacy in Neuromuscular Disorders (USE-NM) was modified from the Multiple Sclerosis (MS) USE-MS scale and administered to patients attending a specialist neuromuscular clinic. The aim was to investigate this measure in neuromuscular disorders and to compare between patient sex, age, and diagnosis. METHODS: The USE-NM was posted to patients recruited from a specialist neuromuscular clinic at the Walton Centre. Responses were subjected to Rasch analysis using RUMM2030 software and descriptive statistics were performed using SPSS version 28. RESULTS: One hundred and ninety-eight patients (56.1% male) grouped by age (<50; 50-59; 60-69; and >69 years) and with varied NM disorders returned the USE-NM. It did not meet the Rasch model expectations due to disordered thresholds of items 6 and 8 ("Sometimes I feel inadequate as a person because of my neuromuscular disorder" and "I feel that my social life would be better if I did not have a neuromuscular disorder"). Following item re-scoring, the modified USE-NM satisfied the Rasch model with a unidimensional scale free from differential item functioning and an overall chi-square probability of 0.146 with good reliability and validity. Post hoc nonparametric testing showed no significant difference in fatigue between sex, age, and neuromuscular diagnoses. DISCUSSION: The Rasch-modified USE-NM offers a measure of self-efficacy for neuromuscular disorders encountered in a typical specialist clinic. Future considerations could be given to assessing any benefits of multidisciplinary team input, across a specialist neuromuscular service.
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Enfermedades Neuromusculares , Autoeficacia , Humanos , Masculino , Femenino , Enfermedades Neuromusculares/diagnóstico , Enfermedades Neuromusculares/psicología , Persona de Mediana Edad , Anciano , Adulto , Psicometría , Factores de Edad , Factores Sexuales , Encuestas y Cuestionarios , Anciano de 80 o más AñosRESUMEN
INTRODUCTION/AIMS: Fatigue is a common and debilitating symptom encountered in the neuromuscular clinic. The 7-item Fatigue Severity Scale (FSS-7) is a Rasch-modified assessment validated in inflammatory neuropathies but not across a typical neuromuscular patient population. The aim of this study was to validate this measure in neuromuscular disorders and to compare between patient sex, age and diagnoses. METHODS: The modified FSS-7 was mailed to patients recruited from a specialist neuromuscular clinic at the Walton Centre. Responses were subjected to Rasch analysis and descriptive statistics were performed on the Rasch converted data. RESULTS: The mFSS-7 met the Rasch model expectations with an overall Chi-square probability of 0.4918, a strict unidimensional scale free from differential item functioning (DIF) that satisfied the model with substantial test-retest reliability using Lin's concordance correlation coefficient 0.71 (95% CI 0.63-0.77). A 15.7% ceiling effect was observed in this patient cohort. Post hoc analysis did not show any significant difference in fatigue between sex, age or neuromuscular diagnoses. DISCUSSION: The self-completed Rasch mFSS-7 showed acceptable test-retest reliability across patients with varied disorders under follow-up in a specialist neuromuscular clinic. The ceiling effect constrains its use for those with the most severe fatigue. Future considerations could include assessment of the benefits of clinical interventions, particularly multidisciplinary team input or dedicated fatigue clinics.
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Fatiga , Enfermedades Neuromusculares , Índice de Severidad de la Enfermedad , Humanos , Masculino , Femenino , Persona de Mediana Edad , Enfermedades Neuromusculares/diagnóstico , Enfermedades Neuromusculares/fisiopatología , Fatiga/diagnóstico , Fatiga/etiología , Fatiga/fisiopatología , Adulto , Reproducibilidad de los Resultados , Anciano , Factores Sexuales , Factores de Edad , Psicometría , Adulto Joven , Encuestas y Cuestionarios/normasRESUMEN
BACKGROUND AND AIMS: In people with relapsing-remitting multiple sclerosis (pwRRMS), data from studies on non-pharmacological factors which may influence relapse risk, other than age, are inconsistent. There is a reduced risk of relapses with increasing age, but little is known about other trajectories in real-world MS care. METHODS: We studied longitudinal questionnaire data from 3885 pwRRMS, covering smoking, comorbidities, disease-modifying therapy (DMT), and patient-reported outcome measures, as well as relapses during the past year. We undertook Rasch analysis, group-based trajectory modelling, and multilevel negative binomial regression. RESULTS: The regression cohort of 6285 data sets from pwRRMS over time showed that being a current smoker was associated with 43.9% greater relapse risk; having 3 or more comorbidities increased risk and increasing age reduced risk. Those diagnosed within the last 2 years showed two distinct trajectories, both reducing in relapse frequency but 25.8% started with a higher rate and took 4 years to reduce to the rate of the second group. In the cohort with at least three data points completed, there were three groups: 73.7% followed a low stable relapse rate, 21.6% started from a higher rate and decreased, and 4.7% had an increasing then decreasing pattern. These different trajectory groups showed significant differences in fatigue, neuropathic pain, disability, health status, quality of life, self-efficacy, and DMT use. CONCLUSIONS: These results provide additional evidence for supporting pwRRMS to stop smoking and underline the importance of timely DMT decisions and treatment initiation soon after diagnosis with RRMS.
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Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Humanos , Esclerosis Múltiple Recurrente-Remitente/epidemiología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Calidad de Vida , Recurrencia , Estado de SaludRESUMEN
INTRODUCTION: Reliable measurement of disability in multiple sclerosis (MS) using a comprehensive, patient self-reported scale, such as the World Health Organization Disability Assessment Schedule (WHODAS) 2.0, would be of clinical and research benefit. METHODS: In the Trajectories of Outcome in Neurological Conditions-MS study, WHODAS 2.0 (WHODAS-36 items for working, WHODAS-32 items if not working, WHODAS-12 items short-form) was examined using Rasch analysis in 5809 people with MS. RESULTS: The 36- and 32-item parallel forms, and the cognitive and physical domains, showed reliability consistent with individual or group use. The 12-item short-form is valid for group use only. Interval level measurement for parametric statistics can be derived from all three scales which showed medium to strong effect sizes for discrimination across characteristics such as age, subtype, and disease duration. Smallest detectable difference for each scale was < 6 on the standardised metric of 0-100 so < 6% of the total range. There was no substantial differential item functioning (DIF) by age, gender, education, working full/part-time, or disease duration; the finding of no DIF for time or sample supports the use of WHODAS 2.0 for longitudinal studies, with the 36- and 32-item versions and the physical and cognitive domains valid for individual patient follow-up. CONCLUSIONS: Disability in MS can be comprehensively measured at interval level by the WHODAS 2.0, and validly monitored over time. Routine use of this self-reported measure in clinical and research practice would give valuable information on the trajectories of disability of individuals and groups.
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Personas con Discapacidad , Esclerosis Múltiple , Humanos , Reproducibilidad de los Resultados , Calidad de Vida/psicología , Personas con Discapacidad/rehabilitación , Evaluación de la Discapacidad , Psicometría , Organización Mundial de la SaludRESUMEN
BACKGROUND: Coping in multiple sclerosis (MS) refers to cognitive and behavioural efforts to manage stresses imposed by the illness. Existing generic and disease-specific coping scales do not meet modern guidelines for scale development and cannot produce interval-level metrics to allow for change scores. OBJECTIVE: The main aim of this study was to develop a brief patient-reported outcome measure for coping in MS, capable of interval-level measurement. METHODS: Qualitative work in 43 people with MS leads to a draft scale which was administered to 5747 participants, with longitudinal collection in 2290. A calibration sample of 1000 subjects split into development and validation sets was used to generate three scales consistent with Rasch model expectations. RESULTS: The total Coping Index-MS (CI-MS-T), CI-MS-Internal (CI-MS-I) and CI-MS-External (CI-MS-E) cover total, internal and externally focused coping. All three scales are capable of interval-level measurement. Trajectory analysis of 9000 questionnaires showed two trajectories in CI-MS-T: Group 1 showed a low level of coping with slight decline over 40 months, while Group 2 had a better and stable level of coping due to improving CI-MS-I which compensated for the deteriorating CI-MS-E over time. CI-MS-T < 30 identified group membership at baseline. CONCLUSION: The CI-MS-T, CI-MS-I and CI-MS-E, comprising 20 items, provide interval-level measurement and are free-for-use in not-for-profit settings.
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Esclerosis Múltiple , Humanos , Adaptación Psicológica , Benchmarking , Medicamentos Genéricos , Medición de Resultados Informados por el PacienteRESUMEN
PURPOSE: Multiple sclerosis (MS) is a neurological disease that has different clinical presentations and illness trajectories. The aim of this study was to explore factors that are important for quality of life (QoL) of people with MS (pwMS), and to understand how they may differ across three subtypes. METHODS: Both convenience and purposive sampling were employed. Semi-structured interviews were conducted with people with relapsing-remitting MS (n = 16), secondary progressive MS (n = 14), and primary progressive MS (n = 13). All interviews were audio recorded and then transcribed verbatim for thematic analysis involving both inductive and deductive processes. A separate analysis for each subtype was made during the inductive process before examining for similarities and differences across the three subtypes in the deductive process. FINDINGS: Four factors were identified to have an important influence on QoL of pwMS: restricted and disrupted enjoyment, disturbed future, challenged sense of self, and well-being of significant others. The themes reflect how pwMS commonly perceived enjoyment as a purpose of life, while also illustrating how their QoL may be questioned because of new perspectives going forward with MS, challenges to their sense of self, and increased concerns for their significant others as a result of MS. Subtype differences were attributed to different illness trajectories: relapsing or progressive. CONCLUSIONS: There are subtype differences in the negative impact of MS on QoL. Clinicians are encouraged to understand the challenges of different illness trajectories, in particular the traumatic nature of relapses and steady worsening of symptoms among those with progressive subtypes of MS.
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Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Humanos , Calidad de Vida/psicología , RecurrenciaRESUMEN
Scab, caused by the plant-pathogenic fungus Venturia effusa, is a major disease of pecan in South America, resulting in loss of quantity and quality of nut yield. Characteristics of the populations of V. effusa in South America are unknown. We used microsatellites to describe the genetic diversity and population structure of V. effusa in South America, and determined the mating type status of the pathogen. The four hierarchically sampled orchard populations from Argentina (AR), Brazil (BRC and BRS), and Uruguay (UR) had moderate to high genotypic and gene diversity. There was evidence of population differentiation (Fst = 0.196) but the correlation between geographic distance and genetic distance was not statistically significant. Genetic differentiation was minimal between the UR, BRC, and BRS populations, and these populations were more clearly differentiated from the AR population. The MAT1-1 and MAT1-2 mating types occurred in all four orchards and their frequencies did not deviate from the 1:1 ratio expected under random mating; however, multilocus linkage equilibrium was rejected in three of the four populations. The population genetics of South American populations of V. effusa has many similarities to the population genetics of V. effusa previously described in the United States. Characterizing the populations genetics and reproductive systems of V. effusa are important to establish the evolutionary potential of the pathogen and, thus, its adaptability-and can provide a basis for informed approaches to utilizing available host resistance and determining phytosanitary needs.
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Ascomicetos , Carya , Ascomicetos/genética , Brasil , Carya/genética , Carya/microbiología , Hongos del Género Venturia , Genes del Tipo Sexual de los Hongos/genética , Variación Genética , Genética de Población , Enfermedades de las Plantas/microbiologíaRESUMEN
BACKGROUND: Motor neuron disease (MND), also known as amyotrophic lateral sclerosis (ALS), is a progressive neurodegenerative condition that may cause dysphagia, as well as limb weakness, dysarthria, emotional lability, and respiratory failure. Since normal salivary production is 0.5 L to 1.5 L daily, loss of salivary clearance due to dysphagia leads to salivary pooling and sialorrhea, often resulting in distress and inconvenience to people with MND. This is an update of a review first published in 2011. OBJECTIVES: To assess the effects of treatments for sialorrhea in MND, including medications, radiotherapy and surgery. SEARCH METHODS: On 27 August 2021, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, AMED, CINAHL, ClinicalTrials.gov and the WHO ICTRP. We checked the bibliographies of the identified randomized trials and contacted trial authors as needed. We contacted known experts in the field to identify further published and unpublished papers. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-RCTs, including cross-over trials, on any intervention for sialorrhea and related symptoms, compared with each other, placebo or no intervention, in people with ALS/MND. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We identified four RCTs involving 110 participants with MND who were described as having intractable sialorrhea or bulbar dysfunction. A well-designed study of botulinum toxin B compared to placebo injected into the parotid and submandibular glands of 20 participants showed that botulinum toxin B may produce participant-reported improvement in sialorrhea, but the confidence interval (CI) was also consistent with no effect. Six of nine participants in the botulinum group and two of nine participants in the placebo group reported improvement (risk ratio (RR) 3.00, 95% CI 0.81 to 11.08; 1 RCT; 18 participants; low-certainty evidence). An objective measure indicated that botulinum toxin B probably reduced saliva production (in mL/5 min) at eight weeks compared to placebo (MD -0.50, 95% CI -1.07 to 0.07; 18 participants, moderate-certainty evidence). Botulinum toxin B may have little to no effect on quality of life, measured on the Schedule for Evaluation of Individual Quality of Life direct weighting scale (SEIQoL-DW; 0-100, higher values indicate better quality of life) (MD -2.50, 95% CI -17.34 to 12.34; 1 RCT; 17 participants; low-certainty evidence). The rate of adverse events may be similar with botulinum toxin B and placebo (20 participants; low-certainty evidence). Trialists did not consider any serious events to be related to treatment. A randomized pilot study of botulinum toxin A or radiotherapy in 20 participants, which was at high risk of bias, provided very low-certainty evidence on the primary outcome of the Drool Rating Scale (DRS; range 8 to 39 points, higher scores indicate worse drooling) at 12 weeks (effect size -4.8, 95% CI -10.59 to 0.92; P = 0.09; 1 RCT; 16 participants). Quality of life was not measured. Evidence for adverse events, measured immediately after treatment (RR 7.00, 95% CI 1.04 to 46.95; 20 participants), and after four weeks (when two people in each group had viscous saliva) was also very uncertain. A phase 2, randomized, placebo-controlled cross-over study of 20 mg dextromethorphan hydrobromide and 10 mg quinidine sulfate (DMQ) found that DMQ may produce a participant-reported improvement in sialorrhea, indicated by a slight improvement (decrease) in mean scores for the primary outcome, the Center for Neurologic Study Bulbar Function Scale (CNS-BFS). Mean total CNS-BFS (range 21 (no symptoms) to 112 (maximum symptoms)) was 53.45 (standard error (SE) 1.07) for the DMQ treatment period and 59.31 (SE 1.10) for the placebo period (mean difference) MD -5.85, 95% CI -8.77 to -2.93) with a slight decrease in the CNS-BFS sialorrhea subscale score (range 7 (no symptoms) to 35 (maximum symptoms)) compared to placebo (MD -1.52, 95% CI -2.52 to -0.52) (1 RCT; 60 participants; moderate-certainty evidence). The trial did not report an objective measure of saliva production or measure quality of life. The study was at an unclear risk of bias. Adverse events were similar to other trials of DMQ, and may occur at a similar rate as placebo (moderate-certainty evidence, 60 participants), with the most common side effects being constipation, diarrhea, nausea, and dizziness. Nausea and diarrhea on DMQ treatment resulted in one withdrawal. A randomized, double-blind, placebo-controlled cross-over study of scopolamine (hyoscine), administered using a skin patch, involved 10 randomized participants, of whom eight provided efficacy data. The participants were unrepresentative of clinic cohorts under routine clinical care as they had feeding tubes and tracheostomy ventilation, and the study was at high risk of bias. The trial provided very low-certainty evidence on sialorrhea in the short term (7 days' treatment, measured on the Amyotrophic Lateral Scelerosis Functional Rating Scale-Revised (ALSFRS-R) saliva item (P = 0.572)), and the amount of saliva production in the short term, as indicated by the weight of a cotton roll (P = 0.674), or daily oral suction volume (P = 0.69). Quality of life was not measured. Adverse events evidence was also very uncertain. One person treated with scopolamine had a dry mouth and one died of aspiration pneumonia considered unrelated to treatment. AUTHORS' CONCLUSIONS: There is some low-certainty or moderate-certainty evidence for the use of botulinum toxin B injections to salivary glands and moderate-certainty evidence for the use of oral dextromethorphan with quinidine (DMQ) for the treatment of sialorrhea in MND. Evidence on radiotherapy versus botulinum toxin A injections, and scopolamine patches is too uncertain for any conclusions to be drawn. Further research is required on treatments for sialorrhea. Data are needed on the problem of sialorrhea in MND and its measurement, both by participant self-report measures and objective tests. These will allow the development of better RCTs.
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Esclerosis Amiotrófica Lateral , Toxinas Botulínicas Tipo A , Trastornos de Deglución , Enfermedad de la Neurona Motora , Sialorrea , Esclerosis Amiotrófica Lateral/complicaciones , Toxinas Botulínicas Tipo A/uso terapéutico , Ensayos Clínicos Fase II como Asunto , Trastornos de Deglución/complicaciones , Trastornos de Deglución/etiología , Diarrea/complicaciones , Humanos , Enfermedad de la Neurona Motora/complicaciones , Náusea , Ensayos Clínicos Controlados Aleatorios como Asunto , Saliva , Derivados de Escopolamina , Sialorrea/tratamiento farmacológico , Sialorrea/etiologíaRESUMEN
Nonribosomal peptide synthetases (NRPSs) generate the core peptide scaffolds of many natural products. These include small cyclic dipeptides such as the insect feeding deterrent peramine, which is a pyrrolopyrazine (PPZ) produced by grass-endophytic Epichloë fungi. Biosynthesis of peramine is catalyzed by the 2-module NRPS, PpzA-1, which has a C-terminal reductase (R) domain that is required for reductive release and cyclization of the NRPS-tethered dipeptidyl-thioester intermediate. However, some PpzA variants lack this R domain due to insertion of a transposable element into the 3' end of ppzA We demonstrate here that these truncated PpzA variants utilize nonenzymatic cyclization of the dipeptidyl thioester to a 2,5-diketopiperazine (DKP) to synthesize a range of novel PPZ products. Truncation of the R domain is sufficient to subfunctionalize PpzA-1 into a dedicated DKP synthetase, exemplified by the truncated variant, PpzA-2, which has also evolved altered substrate specificity and reduced N-methyltransferase activity relative to PpzA-1. Further allelic diversity has been generated by recombination-mediated domain shuffling between ppzA-1 and ppzA-2, resulting in the ppzA-3 and ppzA-4 alleles, each of which encodes synthesis of a unique PPZ metabolite. This research establishes that efficient NRPS-catalyzed DKP biosynthesis can occur in vivo through nonenzymatic dipeptidyl cyclization and presents a remarkably clean example of NRPS evolution through recombinant exchange of functionally divergent domains. This work highlights that allelic variants of a single NRPS can result in a surprising level of secondary metabolite diversity comparable to that observed for some gene clusters.
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Péptido Sintasas , Pirazinas , Ciclización/genética , Barajamiento de ADN , Dicetopiperazinas/química , Epichloe/enzimología , Epichloe/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Péptido Sintasas/química , Péptido Sintasas/genética , Péptido Sintasas/metabolismo , Pirazinas/química , Pirazinas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
Phymatotrichopsis omnivora is a member of Pezizomycetes and causes root rot disease on a broad range of dicotyledonous plants. Using recently generated draft genome sequence data from four P. omnivora isolates, we developed simple sequence repeat (SSR) markers and identified both mating type genes (MAT1-1-1 and MAT1-2-1) in this fungus. To understand the genetic diversity of P. omnivora isolates (n = 43) and spore mats (n = 29) collected from four locations (Oklahoma, Texas, Arizona, and Mexico) and four host crops (cotton, alfalfa, peach, and soybean), we applied 24 SSR markers and showed that of the 72 P. omnivora isolates and spore mats tested, 41 were distinct genotypes. Furthermore, the developed SSR markers did not show cross-transferability to other close relatives of P. omnivora in the class Pezizomycetes. A multiplex PCR detecting both mating type idiomorphs and a reference gene (TUB2) was developed to screen P. omnivora isolates. Based on the dataset we tested, P. omnivora is a heterothallic fungus with both mating types present in the United States in a ratio close to 1:1. We tested P. omnivora spore mats obtained from spatially distinct disease rings that developed in a center-pivot alfalfa field and showed that both mating types can be present not only in the same field but also within a single spore mat. This study shows that P. omnivora has the genetic toolkit for generating sexually diverse progeny, providing impetus for future studies that focus on identifying sexual morphs in nature.
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Ascomicetos , Genes del Tipo Sexual de los Hongos , Genes del Tipo Sexual de los Hongos/genética , Variación Genética , Repeticiones de Microsatélite/genéticaRESUMEN
Phymatotrichopsis omnivora is a destructive plant pathogen causing root rot disease of alfalfa, cotton, pecan, grape, and many other important dicotyledonous species. A member of the family Rhizinaceae, in the class Pezizomycetes, P. omnivora is a soilborne ascomycete fungus that is difficult to maintain in culture, currently genetically intractable, and for which there are no publicly available genomic resources. We have generated draft genome sequences of four P. omnivora isolates obtained from cotton and alfalfa, growing in Texas and Oklahoma. These genome sequences will provide new insights into the biology of the fungus, including the factors responsible for its broad host range and pathogenicity.
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Ascomicetos , Especificidad del Huésped , Ascomicetos/genética , Genómica , Enfermedades de las PlantasRESUMEN
Scab (caused by Venturia carpophila) is a major disease affecting peach in the eastern United States. The aims of the study were to characterize the mating-type loci in V. carpophila, determine whether they are in equilibrium, and assess the population genetic diversity and structure of the pathogen. The mating-type gene MAT1-1-1 was identified in isolate JP3-5 in an available genome sequence, and the MAT1-2-1 gene was PCR amplified from isolate PS1-1, thus indicating a heterothallic structure. Mating-type loci structures were consistent with those of other Venturia spp. (V. effusa and V. inaequalis): the mating-type gene is positioned between APN2 encoding a DNA lyase and a gene encoding a Pleckstrin homology domain. Primers designed to each of the mating-type genes and a reference gene TUB2 were used as a multiplex PCR to screen a population (n = 81) of V. carpophila from various locations in the eastern United States. Mating types in five of the nine populations studied were in equilibrium. Among the 81 isolates, there were 69 multilocus genotypes. A population genetic analysis of the populations with >10 individuals (four populations) showed them to be genetically diverse. Linkage disequilibrium was found in five of nine populations with ≥4 isolates. A discriminant analysis of principal components indicated three genetic clusters, although extensive admixture was observed. Mating-type identification in V. carpophila provides a basis for understanding reproductive methods of the pathogen and can be a basis for further studies of the genetics of the peach scab pathogen.
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Genes del Tipo Sexual de los Hongos , Prunus persica , Hongos del Género Venturia , Genes del Tipo Sexual de los Hongos/genética , Variación Genética , Enfermedades de las Plantas , Análisis de Secuencia de ADNRESUMEN
Structural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organisation influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus, Epichloë festucae. We use Hi-C data to examine the three-dimensional organisation of the genome, and RNA-seq data to investigate how Epichloë genome structure contributes to the suite of transcriptional changes needed to maintain symbiotic relationships with the grass host. Our results reveal a genome in which very repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences that are almost repeat-free. In contrast to other species reported to date, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.
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ADN de Hongos/genética , Epichloe/genética , Regulación Fúngica de la Expresión Génica , Genoma Fúngico/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Secuencia Rica en At/genética , ADN de Hongos/química , Proteínas Fúngicas/genética , Secuencia Rica en GC/genética , Perfilación de la Expresión Génica/métodos , Hifa/genética , Análisis de Secuencia de ADN/métodos , Simbiosis/genéticaRESUMEN
Pecan scab, caused by Venturia effusa, is a devastating disease of pecan (Carya illinoinensis), which results in economic losses on susceptible cultivars throughout the southeastern United States. To enhance our understanding of pathogenicity in V. effusa, we have generated a complete telomere-to-telomere reference genome of V. effusa isolate FRT5LL7-Albino. By combining Illumina MiSeq and Oxford Nanopore MinION data, we assembled a 45.2-Mb genome represented by 20 chromosomes and containing 10,820 putative genes, of which 7,619 have at least one functional annotation. The likely causative mutation of the albino phenotype was identified as a single base insertion and a resulting frameshift in the gene encoding the polyketide synthase ALM1. This genome represents the first full chromosome-level assembly of any Venturia sp.
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Ascomicetos , Carya , Cromosomas Fúngicos , Ascomicetos/genética , Carya/microbiología , Cromosomas Fúngicos/genética , Enfermedades de las Plantas/microbiologíaRESUMEN
OBJECTIVE: The precise relationship between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) is incompletely understood. The association has been described as a continuum, yet data suggest that this may be an oversimplification. Direct comparisons between patients who have behavioural variant FTD (bvFTD) with and without ALS are rare. This prospective comparative study aimed to determine whether there are phenotypic differences in cognition and behaviour between patients with FTD-ALS and bvFTD alone. METHODS: Patients with bvFTD or FTD-ALS and healthy controls underwent neuropsychological testing, focusing on language, executive functions and social cognition. Behavioural change was measured through caregiver interview. Blood samples were screened for known FTD genes. RESULTS: 23 bvFTD, 20 FTD-ALS and 30 controls participated. On cognitive tests, highly significant differences were elicited between patients and controls, confirming the tests' sensitivities to FTD. bvFTD and FTD-ALS groups performed similarly, although with slightly greater difficulty in patients with ALS-FTD on category fluency and a sentence-ordering task that assesses grammar production. Patients with bvFTD demonstrated more widespread behavioural change, with more frequent disinhibition, impulsivity, loss of empathy and repetitive behaviours. Behaviour in FTD-ALS was dominated by apathy. The C9ORF72 repeat expansion was associated with poorer performance on language-related tasks. CONCLUSIONS: Differences were elicited in cognition and behaviour between bvFTD and FTD-ALS, and patients carrying the C9ORF72 repeat expansion. The findings, which raise the possibility of phenotypic variation between bvFTD and FTD-ALS, have clinical implications for early detection of FTD-ALS and theoretical implications for the nature of the relationship between FTD and ALS.
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Esclerosis Amiotrófica Lateral/psicología , Apatía , Proteína C9orf72/genética , Demencia Frontotemporal/psicología , Conducta Impulsiva , Inhibición Psicológica , Cognición Social , Anciano , Esclerosis Amiotrófica Lateral/complicaciones , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/fisiopatología , Estudios de Casos y Controles , Empatía , Función Ejecutiva , Femenino , Demencia Frontotemporal/complicaciones , Demencia Frontotemporal/genética , Demencia Frontotemporal/fisiopatología , Genotipo , Humanos , Lenguaje , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Fenotipo , Estudios Prospectivos , Conducta EstereotipadaRESUMEN
BACKGROUND AND AIMS: The processes that maintain variation in the prevalence of symbioses within host populations are not well understood. While the fitness benefits of symbiosis have clearly been shown to drive changes in symbiont prevalence, the rate of transmission has been less well studied. Many grasses host symbiotic fungi (Epichloë spp.), which can be transmitted vertically to seeds or horizontally via spores. These symbionts may protect plants against herbivores by producing alkaloids or by increasing tolerance to damage. Therefore, herbivory may be a key ecological factor that alters symbiont prevalence within host populations by affecting either symbiont benefits to host fitness or the symbiont transmission rate. Here, we addressed the following questions: Does symbiont presence modulate plant tolerance to herbivory? Does folivory increase symbiont vertical transmission to seeds or hyphal density in seedlings? Do plants with symbiont horizontal transmission have lower rates of vertical transmission than plants lacking horizontal transmission? METHODS: We studied the grass Poa autumnalis and its symbiotic fungi in the genus Epichloë. We measured plant fitness (survival, growth, reproduction) and symbiont transmission to seeds following simulated folivory in a 3-year common garden experiment and surveyed natural populations that varied in mode of symbiont transmission. KEY RESULTS: Poa autumnalis hosted two Epichloë taxa, an undescribed vertically transmitted Epichloë sp. PauTG-1 and E. typhina subsp. poae with both vertical and horizontal transmission. Simulated folivory reduced plant survival, but endophyte presence increased tolerance to damage and boosted fitness. Folivory increased vertical transmission and hyphal density within seedlings, suggesting induced protection for progeny of damaged plants. Across natural populations, the prevalence of vertical transmission did not correlate with symbiont prevalence or differ with mode of transmission. CONCLUSIONS: Herbivory not only mediated the reproductive fitness benefits of symbiosis, but also promoted symbiosis prevalence by increasing vertical transmission of the fungus to the next generation. Our results reveal a new mechanism by which herbivores could influence the prevalence of microbial symbionts in host populations.
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Epichloe , Poa , Endófitos , Herbivoria , Poaceae , SimbiosisRESUMEN
Peramine is a non-ribosomal peptide-derived pyrrolopyrazine (PPZ)-containing molecule with anti-insect properties. Peramine is known to be produced by fungi from genus Epichloë, which form mutualistic endophytic associations with cool-season grass hosts. Peramine biosynthesis has been proposed to require only the two-module non-ribosomal peptide synthetase (NRPS) peramine synthetase (PerA), which is encoded by the 8.3 kb gene perA, though this has not been conclusively proven. Until recently, both peramine and perA were thought to be exclusive to fungi of genus Epichloë; however, a putative perA homologue was recently identified in the genome of the insect-pathogenic fungus Metarhizium rileyi. We use a heterologous expression system and a hydrophilic interaction chromatography-based analysis method to confirm that PerA is the only pathway-specific protein required for peramine biosynthesis. The perA homologue from M. rileyi (MR_perA) is shown to encode a functional peramine synthetase, establishing a precedent for distribution of perA orthologs beyond genus Epichloë. Furthermore, perA is part of a larger seven-gene PPZ cluster in M. rileyi, Metarhizium majus and the stalked-cup lichen fungus Cladonia grayi. These PPZ genes encode proteins predicted to derivatize peramine into more complex PPZ metabolites, with the orphaned perA gene of Epichloë spp. representing an example of reductive evolution.
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Ascomicetos/genética , Genes Fúngicos , Compuestos Heterocíclicos con 2 Anillos/metabolismo , Metarhizium/genética , Familia de Multigenes , Poliaminas/metabolismo , Péptido Sintasas , Poaceae/microbiologíaRESUMEN
Symbiotic Epichloë species are fungal endophytes of cool-season grasses that can produce alkaloids with toxicity to vertebrates and/or invertebrates. Monitoring infections and presence of alkaloids in grasses infected with Epichloë species can provide an estimate of possible intoxication risks for livestock. We sampled 3,046 individuals of 13 different grass species in three regions on 150 study sites in Germany. We determined infection rates and used PCR to identify Epichloë species diversity based on the presence of different alkaloid biosynthesis genes, then confirmed the possible chemotypes with high-performance liquid chromatography (HPLC)/ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) measurements. Infections of Epichloë spp. were found in Festuca pratensis Huds. (81%), Festuca ovina L. aggregate (agg.) (73%), Lolium perenne L. (15%), Festuca rubra L. (15%) and Dactylis glomerata L. (8%). The other eight grass species did not appear to be infected. For the majority of Epichloë-infected L. perenne samples (98%), the alkaloids lolitrem B and peramine were present, but ergovaline was not detected, which was consistent with the genetic evaluation, as dmaW, the gene encoding the first step of the ergot alkaloid biosynthesis pathway, was absent. Epichloë uncinata in F. pratensis produced anti-insect loline compounds. The Epichloë spp. observed in the F. ovina agg. samples showed the greatest level of diversity, and different intermediates of the indole-diterpene pathway could be detected. Epichloë infection rates alone are insufficient to estimate intoxication risks for livestock, as other factors, like the ability of the endophyte to produce the alkaloids, also need to be assessed.IMPORTANCE Severe problems of livestock intoxication from Epichloë-infected forage grasses have been reported from New Zealand, Australia, and the United States, but much less frequently from Europe, and particularly not from Germany. Nevertheless, it is important to monitor infection rates and alkaloids of grasses with Epichloë fungi to estimate possible intoxication risks. Most studies focus on agricultural grass species like Lolium perenne and Festuca arundinacea, but other cool-season grass species can also be infected. We show that in Germany, infection rates and alkaloids differ between grass species and that some of the alkaloids can be toxic to livestock. Changes in grassland management due to changing climate, especially with a shift toward grasslands dominated with Epichloë-infected species such as Lolium perenne, may result in greater numbers of intoxicated livestock in the near future. We therefore suggest regular monitoring of grass species for infections and alkaloids and call for maintaining heterogenous grasslands for livestock.
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Alcaloides/análisis , Endófitos/química , Epichloe/química , Poaceae/química , Poaceae/microbiología , Animales , Cromatografía Líquida de Alta Presión , Dactylis/química , Dactylis/microbiología , Endófitos/fisiología , Epichloe/fisiología , Festuca/química , Festuca/microbiología , Cromatografía de Gases y Espectrometría de Masas , Alemania , Ganado , Lolium/química , Lolium/microbiología , Especificidad de la Especie , Simbiosis , Espectrometría de Masas en TándemRESUMEN
BACKGROUND: Motor neurone disease (MND) places a significant burden on patients, their carers, and healthcare systems. OBJECTIVES: To estimate health utilities and costs of MND within the UK setting. METHODS: Patients with MND, recruited via 22 regional clinics, completed a postal questionnaire of a cost and quality-of-life survey. Health outcome assessment included the EuroQoL (EQ)-5D-5L, EQ-5D-visual analogue scale, Amyotrophic Lateral Sclerosis Utility Index, and the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised. Clinical staging was based on the Kings and Milano-Torino (MiToS) systems. The questionnaire asked about patients' use of primary, secondary, and community care services in the previous 3 months. Variability in total costs was examined using regression models. RESULTS: 595 patients were included in the health utility analysis, of whom 584 patients also completed a resource use questionnaire. Mean health utility decreased and costs increased between consecutive Kings stages, from 0.76 (95% CI 0.71-0.80) and £1096 (£757-£1240) in Kings stage 1, to 0.50 (0.45-0.54) and £3311 (£2666-£4151) in stage 4, respectively. The changes by MiToS stages were from 0.71 (0.69-0.73) and £1115 (£937-£1130) in MiToS stage 0, to 0.25 (0.07-0.42) and £2899 (£2190-£3840) in stage 2. Kings stages 3 and 4 and MiToS stages 1 and 2, respectively, were significant in explaining variability in total costs. CONCLUSIONS: The impact of MND on health utilities and costs differs by disease severity. The data provided here can be used in cost-effectiveness analyses and to inform decision-making regarding healthcare provision for people with MND.
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Esclerosis Amiotrófica Lateral/economía , Índice de Severidad de la Enfermedad , Anciano , Costos y Análisis de Costo , Evaluación de la Discapacidad , Femenino , Servicios de Salud/economía , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , Años de Vida Ajustados por Calidad de Vida , Reino UnidoRESUMEN
OBJECTIVE: Understanding the use of coping strategies and which factors are associated with strategy utilization might help clinical staff anticipate which coping strategies individuals are more likely to utilize. In this study, we assess coping strategy use in the motor neuron disease (MND, also known as amyotrophic lateral sclerosis [ALS]) population and examine associations of demographic and disease variables with individual coping strategies. PARTICIPANTS AND METHODS: A total of 233 participants with MND/ALS were recruited into the ongoing Trajectories of Outcomes in Neurological Conditions study from MND clinics across the United Kingdom. Participants completed a questionnaire pack collecting data on demographics and a range of patient-reported measures including the Coping Orientations to Problems Experienced scale. Associations between demographic and clinical characteristics and coping strategies were examined by simple and multiple ordinal logistic regression. RESULTS: The most commonly used strategy was Acceptance, followed by Active Coping, Planning and Positive Re-interpretation and Growth. The least used strategies were Substance Use, Turning to Religion and Denial. Ten out of the fifteen strategies showed statistically significant associations with demographic and clinical characteristics. Most markedly, females were found to utilize many strategies more than males, namely Restraint, Seeking Instrumental Social Support, Seeking Emotional Social Support, Focus on and Venting of Emotions, Behavioural Disengagement and Mental Disengagement. CONCLUSION: Clinical staff should be aware that coping strategy use is associated with several demographic and disease characteristics. Targeted advice on coping may improve coping capacity and facilitate psychosocial adjustment.