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1.
Bioengineering (Basel) ; 11(7)2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39061777

RESUMO

As both the proportion of older people and the length of life increases globally, a rise in age-related degenerative diseases, disability, and prolonged dependency is projected. However, more sophisticated biomedical materials, as well as an improved understanding of human disease, is forecast to revolutionize the diagnosis and treatment of conditions ranging from osteoarthritis to Alzheimer's disease as well as impact disease prevention. Another, albeit quieter, revolution is also taking place within society: human augmentation. In this context, humans seek to improve themselves, metamorphosing through self-discipline or more recently, through use of emerging medical technologies, with the goal of transcending aging and mortality. In this review, and in the pursuit of improved medical care following aging, disease, disability, or injury, we first highlight cutting-edge and emerging materials-based neuroprosthetic technologies designed to restore limb or organ function. We highlight the potential for these technologies to be utilized to augment human performance beyond the range of natural performance. We discuss and explore the growing social movement of human augmentation and the idea that it is possible and desirable to use emerging technologies to push the boundaries of what it means to be a healthy human into the realm of superhuman performance and intelligence. This potential future capability is contrasted with limitations in the right-to-repair legislation, which may create challenges for patients. Now is the time for continued discussion of the ethical strategies for research, implementation, and long-term device sustainability or repair.

2.
Biomedica ; 44(1): 16-34, 2024 03 31.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38648344

RESUMO

Paraquat®, or N,N'-dimethyl-4,4'-bipyridinium dichloride, is a bipyridyl compound used as a non-selective herbicide and desiccant that can cause acute poisoning through all routes of exposure. There is no known antidote, and the available treatments are based on avoiding its absorption and timely removing it, in adults and children. We describe a case series of 14 pediatric patients from the department of Cauca, Colombia, with acute intoxication after oral intake of paraquat. Patients were referred to a medium-high complexity hospital in southwestern Colombia and treated according to an institutional protocol for acute paraquat poisoning. Acute paraquat poisoning after oral ingestion is associated with a high mortality rate, even with timely medical attention, as the compound has no known antidote and quickly reaches systemic concentrations for fulminant poisoning. Based on the available literature, our center has proposed a clinical protocol including early standard management, immunosuppressive and antioxidant treatments, and systemic removal techniques. This protocol suggests an adequate approach to acute paraquat poisoning in the pediatric population.


El dicloruro de 1,1'-dimetil-4,4'-bipiridilo (Paraquat®) es un compuesto químico de la familia de las piridinas, utilizado como herbicida no selectivo y desecante. Este compuesto puede causar intoxicación aguda por todas las vías de exposición. En el momento, no hay un antídoto conocido y los tratamientos disponibles, incluidos los pediátricos, se basan en contrarrestar su absorción y propiciar su remoción oportuna. Se describe una serie de casos de 14 pacientes pediátricos, procedentes en su mayoría del departamento del Cauca, con intoxicación aguda por ingestión de paraquat. Los pacientes fueron remitidos y atendidos en un hospital de mediana a alta complejidad en el suroccidente colombiano, con un protocolo institucional para el manejo de la intoxicación aguda por el herbicida. La intoxicación aguda con paraquat por vía oral se asocia con una alta tasa de mortalidad, aún con atención médica oportuna, pues fácilmente se alcanzan concentraciones sistémicas para ser fulminante. Basado en la literatura disponible, el Hospital Universitario San José ha propuesto un protocolo clínico ­adecuado para la intoxicación aguda por paraquat en población pediátrica­ que incluye manejo estándar temprano, tratamiento inmunosupresor y antioxidante, y técnicas para su remoción sistémica.


Assuntos
Algoritmos , Herbicidas , Paraquat , Humanos , Paraquat/intoxicação , Criança , Feminino , Masculino , Pré-Escolar , Adolescente , Herbicidas/intoxicação , Intoxicação/terapia , Intoxicação/tratamento farmacológico , Colômbia , Doença Aguda , Lactente , Antioxidantes/uso terapêutico , Protocolos Clínicos , Antídotos/uso terapêutico
3.
J Fungi (Basel) ; 10(3)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38535209

RESUMO

Colletotrichum coccodes (Wallr.) Hughes is an asexual fungus with five vegetative compatibility groups. It was postulated that C. coccodes was isolated at the center of origin of potato at one time, and due to the movement of potato around the globe, the fungus was established on each continent but became bottlenecked and genetically unable to form stable heterokaryons via vegetative compatibility grouping (VCG) studies. The objectives of this study were (i) to determine if the VCGs around the world are related to the VCGs in Chile, (ii) to determine the diversity of C. coccodes populations in Chile, and (iii) to find any evidence for a cryptic sexual life cycle for this fungus. Worldwide C. coccodes populations have been found to be genetically correlated and belong to one or more C. coccodes-identified VCGs. The most distributed VCG in Chile was VCG2, which is the most common VCG in North America. We hypothesize that one or more VCGs had spread from Chile to the rest of the world. Precautions and further studies should be investigated by using other molecular markers and gene sequencing.

4.
Folia Microbiol (Praha) ; 68(2): 277-290, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36273059

RESUMO

Deforestation has a large impact on soil fertility, especially on steep slopes, but by applying sustainable management practices, local communities in Oaxaca (Mexico) have tried to avoid the most negative effects on the forest ecosystems they manage. In this study, the characteristics and bacterial community structure were investigated from soil sampled in triplicate (n = 3) with different land use, i.e., arable, natural forest, sustainable managed, and reforested soil. The pH was significantly higher in the arable (6.2) than in the forest soils (≤ 5.3), while the organic matter was > 2 times higher in the natural forest (80.4 g/kg) and sustainable managed soil (86.3 g/kg) than in the arable (36.8 g/kg) and cleared and reforested soil (39.3 g/kg). The higher organic matter content in the first two soils was due to leaf litter, absent in the other soils. The species richness (q = 0), the typical (q = 1) and dominant bacteria (q = 2) were not affected significantly by land use. The beta diversity, however, showed a significant effect of land use on species richness (p = 0.0029). Proteobacteria (40.135%) and Actinobacteria (20.15%) were the dominant bacterial phyla, and Halomonas (14.50%) and the Verrucomicrobia DA101 (3.39%) were the dominant genera. The bacterial communities were highly significantly different in soil with different land use considering the taxonomic level of genus and OTUs (p ≤ 0.003). It was found that the sustainable managed forest provided the local community with sellable wood while maintaining the soil organic matter content, i.e., sequestered C and without altering the bacterial community structure.


Assuntos
Actinobacteria , Ecossistema , Florestas , Bactérias/genética , Solo/química , Actinobacteria/genética , Microbiologia do Solo
5.
Arthroscopy ; 37(9): 2783-2796, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33957215

RESUMO

PURPOSE: The purpose of this study was to evaluate clinical and radiologic outcomes of arthroscopic superior capsular reconstruction (ASCR) with fascia lata autograft in patients with irreparable rotator cuff tears (IRCTs) performed using a single lateral-row fixation technique. METHODS: We studied a retrospective case series of patients with large or massive IRCTs for ASCR with fascia lata autograft. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) and the Constant score. Healing of the graft was assessed by magntic resonance imaging or ultrasound. Acromiohumeral distance was evaluated by radiographs. RESULTS: Thirty-one patients with an average age of 61 years and an average follow-up of 35 months (24-51 months) underwent ASCR with fascia lata autograft. There was a significant improvement in VAS (7.7-0.7), Constant score (36.0-78.7), forward elevation (115°-171°), external rotation (33°-50°), strength (0.3 kg-2.3 kg), and acromiohumeral distance (6.1 mm-8.6 mm) (P < 0.001). Graft failure was present in 13.8% of patients, as shown by magnetic resonance imaging (26 patients) or ultrasound (3 patients). Patients with failed ASCR showed worse Constant scores (68.5.8 vs 80.2, P = 0.007), worse VAS (2.5 vs 0.4, P = 0.00002), worse external rotation (20° vs 54°, P = 0.004), lower acromiohumeral distance (5mm vs 9mm, P = 0.007), and a high association with the presence of os acromiale (χ2P = 0.003). No revision or subsequent surgical procedures were required. CONCLUSIONS: ASCR, with autologous fascia lata and single lateral row configuration, is an effective option in irreparable rotator cuff tears and results in clinical and radiologic improvement. LEVEL OF EVIDENCE: Level IV, retrospective case series.


Assuntos
Lesões do Manguito Rotador , Articulação do Ombro , Artroscopia , Fascia Lata , Seguimentos , Humanos , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Estudos Retrospectivos , Lesões do Manguito Rotador/cirurgia , Resultado do Tratamento
6.
Rev. chil. pediatr ; 91(4): 521-528, ago. 2020. tab
Artigo em Espanhol | LILACS | ID: biblio-1138666

RESUMO

Resumen: Introducción: Al menos 50% de los pacientes pediátricos portadores de artritis idiopática juvenil (AIJ) continuará control en reumatología adulto. La clasificación de la Liga Internacional de Asociaciones de Reumatología (ILAR) vigente, actualmente en revisión, difiere de la clasificación de las artritis inflamatorias del adulto. Se ha reportado cambios de categoría en 10,8% de los pacientes durante el seguimiento. Objetivo: Analizar los pacientes con AIJ seguidos al menos 7 años para objetivar cambios de diagnós tico en la transición, e identificar factores de mal pronóstico funcional. Pacientes y Método: Estudio retrospectivo en base a registros clínicos. Se incluyó a la totalidad de los pacientes con AIJ controla dos en policlínico pediátrico del Hospital de Puerto Montt entre el año 2005 y 2017, que cumplieron siete o más años de seguimiento. Se realizó análisis descriptivo en base a variables clínicas: categoría diagnóstica, tiempo de evolución al diagnóstico, actividad clínica y serológica, y tiempo de evolución al inicio de la terapia farmacológica. Resultados: Se evaluaron 18 pacientes, 3 Oligo-articular (OA) persistente, 1 OA extendida, 4 Poli-articular (PA) factor reumatoide (FR) negativo, 4 PA FR positivo, 5 Sistémicas, 1 Psoriática, todos con seguimiento mayor a 7 años. Once de 18 niños fueron transfe ridos a adultos. Tres de 11 cambiaron de diagnóstico a Artritis Reumatoide (AR) más otra enferme dad autoinmune: Síndrome de Sjögren + Lupus eritematoso sistémico, Púrpura trombocitopénico inmune, Enfermedad autoinmune no clasificada y cinco de 11 niños de categoría ILAR: OA a Artritis reumatoide juvenil, OA extendida a PA FR negativo, 3 Sistémicas a PA FR negativo. Edad de inicio, formas poli-articulares, retrasos en diagnóstico y comienzo de terapia se asociaron a secuelas e infla mación persistente. Conclusiones: Ocho de once pacientes transferidos cambiaron denominación diagnóstica y/o presentaron otras enfermedades autoinmunes. Algunos factores de mal pronóstico deben mejorar.


Abstract: Introduction: At least 50% of pediatric patients with Juvenile Idiopathic Arthritis (JIA) will require continued fo llow-up in adult rheumatology. The present International League of Associations for Rheumatology (ILAR) classification, currently under revision, differs from its classification of inflammatory arthritis in adults. Category changes have been reported in 10.8% of patients during follow-up. Objective: To analyze JIA patients in follow-up for at least 7 years to detect diagnosis changes during transition to adult care, identifying factors of poor functional prognosis. Patients and Method: Retrospective study based on medical records of JIA patients seen at the pediatric polyclinic of the Puerto Montt Hospital between 2005 and 2017, who were monitored for at least 7 years. Descriptive analysis was performed according to clinical variables: diagnostic category, evolution before diagnosis, clinical and serological activity, and evolution before starting drug therapy. Results: We evaluated 18 pa tients, corresponding to 3 patients with persistent oligoarticular arthritis (OA), 1 with extended OA, 4 with polyarticular arthritis (PA) rheumatoid factor (RF) negative, 4 with PA RF positive, 5 with syste mic JIA, and 1 with psoriatic arthritis, all have had follow-up more than 7 years. 11 out of 18 patients transitioned to adult care. Three out of 11 patients changed diagnosis to Rheumatoid Arthritis (RA) plus another autoimmune disease such as Sjögren's Syndrome + Systemic Lupus Erythematosus, Immune thrombocytopenia, or unclassified autoimmune disease, and 5 out of 11 children changed ILAR category from OA to Juvenile Rheumatoid Arthritis, extended OA to PA RF negative, and 3 from Systemic arthritis to PA RF negative. Age of onset, polyarticular forms, delay in diagnosis, and the start of therapy were associated with sequelae and persistent inflammation. Conclusions: Eight of the eleven JIA patients who transitioned to adult care changed their diagnosis or presented other autoimmune diseases. Some factors of poor prognosis must improve.


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Artrite Juvenil/diagnóstico , Transição para Assistência do Adulto , Artrite Juvenil/classificação , Artrite Juvenil/complicações , Artrite Juvenil/terapia , Artrite Reumatoide/classificação , Artrite Reumatoide/complicações , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/terapia , Prognóstico , Artrite Psoriásica/complicações , Artrite Psoriásica/diagnóstico , Artrite Psoriásica/terapia , Estudos Retrospectivos , Seguimentos , Púrpura Trombocitopênica Idiopática/complicações , Púrpura Trombocitopênica Idiopática/diagnóstico , Púrpura Trombocitopênica Idiopática/terapia , Assistência ao Convalescente , Progressão da Doença , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia
7.
Rev Chil Pediatr ; 91(4): 521-528, 2020 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-33399728

RESUMO

INTRODUCTION: At least 50% of pediatric patients with Juvenile Idiopathic Arthritis (JIA) will require continued fo llow-up in adult rheumatology. The present International League of Associations for Rheumatology (ILAR) classification, currently under revision, differs from its classification of inflammatory arthritis in adults. Category changes have been reported in 10.8% of patients during follow-up. OBJECTIVE: To analyze JIA patients in follow-up for at least 7 years to detect diagnosis changes during transition to adult care, identifying factors of poor functional prognosis. PATIENTS AND METHOD: Retrospective study based on medical records of JIA patients seen at the pediatric polyclinic of the Puerto Montt Hospital between 2005 and 2017, who were monitored for at least 7 years. Descriptive analysis was performed according to clinical variables: diagnostic category, evolution before diagnosis, clinical and serological activity, and evolution before starting drug therapy. RESULTS: We evaluated 18 pa tients, corresponding to 3 patients with persistent oligoarticular arthritis (OA), 1 with extended OA, 4 with polyarticular arthritis (PA) rheumatoid factor (RF) negative, 4 with PA RF positive, 5 with syste mic JIA, and 1 with psoriatic arthritis, all have had follow-up more than 7 years. 11 out of 18 patients transitioned to adult care. Three out of 11 patients changed diagnosis to Rheumatoid Arthritis (RA) plus another autoimmune disease such as Sjögren's Syndrome + Systemic Lupus Erythematosus, Immune thrombocytopenia, or unclassified autoimmune disease, and 5 out of 11 children changed ILAR category from OA to Juvenile Rheumatoid Arthritis, extended OA to PA RF negative, and 3 from Systemic arthritis to PA RF negative. Age of onset, polyarticular forms, delay in diagnosis, and the start of therapy were associated with sequelae and persistent inflammation. CONCLUSIONS: Eight of the eleven JIA patients who transitioned to adult care changed their diagnosis or presented other autoimmune diseases. Some factors of poor prognosis must improve.


Assuntos
Artrite Juvenil/diagnóstico , Transição para Assistência do Adulto , Adolescente , Assistência ao Convalescente , Artrite Juvenil/classificação , Artrite Juvenil/complicações , Artrite Juvenil/terapia , Artrite Psoriásica/complicações , Artrite Psoriásica/diagnóstico , Artrite Psoriásica/terapia , Artrite Reumatoide/classificação , Artrite Reumatoide/complicações , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/terapia , Progressão da Doença , Feminino , Seguimentos , Humanos , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia , Masculino , Prognóstico , Púrpura Trombocitopênica Idiopática/complicações , Púrpura Trombocitopênica Idiopática/diagnóstico , Púrpura Trombocitopênica Idiopática/terapia , Estudos Retrospectivos , Adulto Jovem
8.
Phytopathology ; 109(7): 1280-1292, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30785376

RESUMO

Cercospora leaf spot, caused by Cercospora beticola, is a highly destructive disease of Beta vulgaris subsp. vulgaris worldwide. C. beticola populations are usually characterized by high genetic diversity, but little is known of the relationships among populations from different production regions around the world. This information would be informative of population origin and potential pathways for pathogen movement. For the current study, the genetic diversity, differentiation, and relationships among 948 C. beticola isolates in 28 populations across eight geographic regions were investigated using 12 microsatellite markers. Genotypic diversity, as measured by Simpson's complement index, ranged from 0.18 to 1.00, while pairwise index of differentiation values ranged from 0.02 to 0.42, with the greatest differentiation detected between two New York populations. In these populations, evidence for recent expansion was detected. Assessment of population structure identified two major clusters: the first associated with New York, and the second with Canada, Chile, Eurasia, Hawaii, Michigan, North Dakota, and one population from New York. Inferences of gene flow among these regions suggested that the source for one cluster likely is Eurasia, whereas the source for the other cluster is not known. These results suggest a shared origin of C. beticola populations across regions, except for part of New York, where population divergence has occurred. These findings support the hypothesis that dispersal of C. beticola occurs over long distances.


Assuntos
Beta vulgaris , Doenças das Plantas/microbiologia , Beta vulgaris/microbiologia , Canadá , Chile , Variação Genética , Havaí , Michigan , New York , North Dakota
9.
Ecol Evol ; 7(6): 1882-1891, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28331595

RESUMO

Functional diversity is intimately linked with community assembly processes, but its large-scale patterns of variation are often not well understood. Here, we investigated the spatiotemporal changes in multiple trait dimensions ("trait space") along vertical intertidal environmental stress gradients and across a landscape scale. We predicted that the range of the trait space covered by local assemblages (i.e., functional richness) and the dispersion in trait abundances (i.e., functional dispersion) should increase from high- to low-intertidal elevations, due to the decreasing influence of environmental filtering. The abundance of macrobenthic algae and invertebrates was estimated at four rocky shores spanning ca. 200 km of the coast over a 36-month period. Functional richness and dispersion were contrasted against matrix-swap models to remove any confounding effect of species richness on functional diversity. Random-slope models showed that functional richness and dispersion significantly increased from high- to low-intertidal heights, demonstrating that under harsh environmental conditions, the assemblages comprised similar abundances of functionally similar species (i.e., trait convergence), while that under milder conditions, the assemblages encompassed differing abundances of functionally dissimilar species (i.e., trait divergence). According to the Akaike information criteria, the relationship between local environmental stress and functional richness was persistent across sites and sampling times, while functional dispersion varied significantly. Environmental filtering therefore has persistent effects on the range of trait space covered by these assemblages, but context-dependent effects on the abundances of trait combinations within such range. Our results further suggest that natural and/or anthropogenic factors might have significant effects on the relative abundance of functional traits, despite that no trait addition or extinction is detected.

10.
PLoS One ; 10(11): e0142406, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26555075

RESUMO

We previously characterized the retinoblastoma tumor suppressor protein (Rb) as a regulator of adherens junction assembly and cell-to-cell adhesion in osteoblasts. This is a novel function since Rb is predominantly known as a cell cycle repressor. Herein, we characterized the molecular mechanisms by which Rb performs this function, hypothesizing that Rb controls the activity of known regulators of adherens junction assembly. We found that Rb represses the expression of the p21-activated protein kinase (Pak1), an effector of the small Rho GTPase Rac1. Rac1 is a well-known regulator of adherens junction assembly whose increased activity in cancer is linked to perturbations of intercellular adhesion. Using nuclear run-on and luciferase reporter transcription assays, we found that Pak1 repression by Rb is transcriptional, without affecting Pak1 mRNA and protein stability. Pak1 promoter bioinformatics showed multiple E2F1 binding sites within 155 base pairs of the transcriptional start site, and a Pak1-promoter region containing these E2F sites is susceptible to transcriptional inhibition by Rb. Chromatin immunoprecipitations showed that an Rb-E2F complex binds to the region of the Pak1 promoter containing the E2F1 binding sites, suggesting that Pak1 is an E2F target and that the repressive effect of Rb on Pak1 involves blocking the trans-activating capacity of E2F. A bioinformatics analysis showed elevated Pak1 expression in several solid tumors relative to adjacent normal tissue, with both Pak1 and E2F increased relative to normal tissue in breast cancer, supporting a cancer etiology for Pak1 up-regulation. Therefore, we propose that by repressing Pak1 expression, Rb prevents Rac1 hyperactivity usually associated with cancer and related to cytoskeletal derangements that disrupt cell adhesion, consequently enhancing cancer cell migratory capacity. This de-regulation of cell adhesion due to Rb loss could be part of the molecular events associated with cancer progression and metastasis.


Assuntos
Osteoblastos/metabolismo , Proteína do Retinoblastoma/fisiologia , Transcrição Gênica/fisiologia , Quinases Ativadas por p21/metabolismo , Células 3T3 , Animais , Fator de Transcrição E2F1/metabolismo , Inativação Gênica , Camundongos , Osteoblastos/citologia , Regiões Promotoras Genéticas , Ligação Proteica , Proteína do Retinoblastoma/metabolismo , Quinases Ativadas por p21/genética
11.
Pest Manag Sci ; 69(1): 35-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22761173

RESUMO

BACKGROUND: Cercospora leaf spot (CLS), caused by the fungus Cercospora beticola, is the most serious foliar disease of sugar beet (Beta vulgaris L.) worldwide. Disease control is mainly achieved by timely fungicide applications. In 2011, CLS control failures were reported in spite of application of quinone outside inhibitor (QoI) fungicide in several counties in Michigan, United States. The purpose of this study was to confirm the resistant phenotype and identify the molecular basis for QoI resistance of Michigan C. beticola isolates. RESULTS: Isolates collected in Michigan in 1998 and 1999 that had no previous exposure to the QoI fungicides trifloxystrobin or pyraclostrobin exhibited QoI EC(50) values of ≤ 0.006 µg mL(-1) . In contrast, all isolates obtained in 2011 exhibited EC(50) values of > 0.92 µg mL(-1) to both fungicides and harbored a mutation in cytochrome b (cytb) that led to an amino acid exchange from glycine to alanine at position 143 (G143A) compared with baseline QoI-sensitive isolates. Microsatellite analysis of the isolates suggested that QoI resistance emerged independently in multiple genotypic backgrounds at multiple locations. A real-time PCR assay utilizing dual-labeled fluorogenic probes was developed to detect and differentiate QoI-resistant isolates harboring the G143A mutation from sensitive isolates. CONCLUSION: The G143A mutation in cytb is associated with QoI resistance in C. beticola. Accurate monitoring of this mutation will be essential for fungicide resistance management in this pathosystem.


Assuntos
Ascomicetos/genética , Citocromos b/genética , Farmacorresistência Fúngica/efeitos dos fármacos , Proteínas Fúngicas/genética , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Mutação Puntual/efeitos dos fármacos , Acetatos/farmacologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/isolamento & purificação , Beta vulgaris/microbiologia , Carbamatos/farmacologia , Citocromos b/metabolismo , Proteínas Fúngicas/metabolismo , Iminas/farmacologia , Metacrilatos/farmacologia , Michigan , Repetições de Microssatélites , Pirazóis/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Estrobilurinas
12.
Fungal Biol ; 116(4): 511-21, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22483049

RESUMO

Cercospora leaf spot, caused by the hemibiotrophic fungal pathogen Cercospora beticola, is the most economically damaging foliar disease of sugarbeet worldwide. Although most C. beticola populations display characteristics reminiscent of sexual recombination, no teleomorph has been described. To assess whether populations in northern United States have characteristics consistent with sexual reproduction, 1024 isolates collected over a 3-y period were analyzed for frequency and distribution of mating type genes. After clone correction, an approximately equal distribution of mating types was found for each sampling year. Mating type frequency was also assessed in individual lesions. Lesions always consisted of isolates with a single mating type and microsatellite haplotype, but both mating types and up to five microsatellite haplotypes could be found on an individual leaf. The MAT1-1-1 and MAT1-2-1 genes were sequenced from 28 MAT1-1 and 28 MAT1-2 isolates, respectively. Three MAT1-1-1 nucleotide haplotypes were identified that encoded a single amino acid sequence. For MAT1-2-1, five nucleotide haplotypes were identified that encoded four protein variants. MAT1-1-1 and MAT1-2-1 gene expression analyses were conducted on plants inoculated with either or both mating types. MAT1-1-1 expression remained low, but MAT1-2-1 spiked during late stages of colonization. A segment of the MAT1-2-1 coding sequence was also found in MAT1-1 isolates. Taken together, these results suggest that C. beticola has the potential for sexual reproduction.


Assuntos
Ascomicetos/crescimento & desenvolvimento , Ascomicetos/genética , Genes Fúngicos Tipo Acasalamento , Recombinação Genética , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Beta vulgaris/microbiologia , DNA Fúngico/química , DNA Fúngico/genética , Haplótipos , Repetições de Microssatélites , Dados de Sequência Molecular , Doenças das Plantas/microbiologia , Polimorfismo Genético , Análise de Sequência de DNA , Estados Unidos
13.
Methods Mol Biol ; 835: 385-92, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22183666

RESUMO

Fungicide resistance assays are useful to determine if a fungal pathogen has developed resistance to a fungicide used to manage the disease it causes. Laboratory assays are used to determine loss of sensitivity, or resistance, to a fungicide and can explain fungicide failures and for developing successful fungicide recommendations in the field. Laboratory assays for fungicide resistance are conducted by measuring reductions in growth or spore germination of fungi in the presence of fungicide, or by molecular procedures. This chapter describes two techniques for measuring fungicide resistance, using the sugarbeet leaf spot fungus Cercospora beticola as a model for the protocol. Two procedures are described for fungicides from two different classes; growth reduction for triazole (sterol demethylation inhibitor; DMI) fungicides, and inhibition of spore germination for quinone outside inhibitor (QoI) fungicides.


Assuntos
Ascomicetos/crescimento & desenvolvimento , Fungicidas Industriais/metabolismo , Metacrilatos/metabolismo , Triazóis/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento
14.
PLoS One ; 5(11): e13954, 2010 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-21085651

RESUMO

The retinoblastoma protein (pRb) is a cell cycle regulator inactivated in most human cancers. Loss of pRb function results from mutations in the gene coding for pRb or for any of its upstream regulators. Although pRb is predominantly known as a cell cycle repressor, our data point to additional pRb functions in cell adhesion. Our data show that pRb regulates the expression of a wide repertoire of cell adhesion genes and regulates the assembly of the adherens junctions required for cell adhesion. We conducted our studies in osteoblasts, which depend on both pRb and on cell-to-cell contacts for their differentiation and function. We generated knockout mice in which the RB gene was excised specifically in osteoblasts using the cre-lox P system and found that osteoblasts from pRb knockout mice did not assemble adherens junction at their membranes. pRb depletion in wild type osteoblasts using RNAi also disrupted adherens junctions. Microarrays comparing pRb-expressing and pRb-deficient osteoblasts showed that pRb controls the expression of a number of cell adhesion genes, including cadherins. Furthermore, pRb knockout mice showed bone abnormalities consistent with osteoblast adhesion defects. We also found that pRb controls the function of merlin, a well-known regulator of adherens junction assembly, by repressing Rac1 and its effector Pak1. Using qRT-PCR, immunoblots, co-immunoprecipitation assays, and immunofluorescent labeling, we observed that pRb loss resulted in Rac1 and Pak1 overexpression concomitant with merlin inactivation by Pak1, merlin detachment from the membrane, and adherens junction loss. Our data support a pRb function in cell adhesion while elucidating the mechanism for this function. Our work suggests that in some tumor types pRb inactivation results in both a loss of cell cycle control that promotes initial tumor growth as well as in a loss of cell-to-cell contacts, which contributes to later stages of metastasis.


Assuntos
Osteoblastos/metabolismo , Proteína do Retinoblastoma/metabolismo , Células 3T3 , Junções Aderentes/genética , Junções Aderentes/fisiologia , Animais , Caderinas/genética , Caderinas/metabolismo , Adesão Celular/genética , Adesão Celular/fisiologia , Comunicação Celular/genética , Comunicação Celular/fisiologia , Proliferação de Células , Células Cultivadas , Feminino , Perfilação da Expressão Gênica , Immunoblotting , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos SCID , Modelos Biológicos , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Osteoblastos/citologia , Osteogênese/genética , Osteogênese/fisiologia , Osteossarcoma/genética , Osteossarcoma/metabolismo , Interferência de RNA , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Crânio/embriologia , Crânio/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo , Proteínas rac de Ligação ao GTP/genética , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP
15.
Plant Dis ; 94(11): 1272-1282, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30743643

RESUMO

Cercospora leaf spot, caused by the fungus Cercospora beticola Sacc., is the most serious and important foliar disease of sugar beet (Beta vulgaris L.) wherever it is grown worldwide. Cercospora leaf spot first caused economic damage in North Dakota and Minnesota in 1980, and the disease is now endemic. This is the largest production area for sugar beet in the United States, producing 5.5 to 6.0 million metric tons on approximately 300,000 ha, which is 56% of the sugar beet production in the United States. This Plant Disease feature article details a cooperative effort among the participants in the sugar beet industry in this growing area and represents a successful collaboration and team effort to confront and change a fungicide resistance crisis to a fungicide success program. As a case study of success for managing fungicide resistance, it will serve as an example to other pathogen-fungicide systems and provide inspiration and ideas for long-term disease management by fungicides.

16.
Phytopathology ; 97(7): 835-41, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18943932

RESUMO

ABSTRACT Fusarium graminearum causes Fusarium head blight (FHB) in small grains worldwide. Although primarily a pathogen of cereals, it also can infect noncereal crops such as potato and sugar beet in the United States. We used a real-time polymerase chain reaction (PCR) method based on intergenic sequences specific to the trichodiene synthase gene (Tri5) from F. graminearum. TaqMan probe and primers were designed and used to estimate DNA content of the pathogen (FgDNA) in the susceptible wheat cv. Grandin after inoculation with the 21 isolates of F. graminearum collected from potato, sugar beet, and wheat. The presence of nine mycotoxins was analyzed in the inoculated wheat heads by gas chromatography and mass spectrometry. All isolates contained the Tri5 gene and were virulent to cv. Grandin. Isolates of F. graminearum differed significantly in virulence (expressed as disease severity), FgDNA content, and mycotoxin accumulation. Potato isolates showed greater variability in producing different mycotoxins than sugar beet and wheat isolates. Correlation analysis showed a significant (P < 0.001) positive relationship between FgDNA content and FHB severity or deoxynivalenol (DON) production. Moreover, a significant (P < 0.001) positive correlation between FHB severity and DON content was observed. Our findings revealed that F. graminearum causing potato dry rot and sugar beet decay could be potential sources of inoculum for FHB epidemics in wheat. Real-time PCR assay provides sensitive and accurate quantification of F. graminearum in wheat and can be useful for monitoring the colonization of wheat grains by F. graminearum in controlled environments, and evaluating wheat germplasms for resistance to FHB.

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