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1.
Phytopathology ; 112(2): 414-421, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34080915

RESUMEN

Until recently, genotypes of Phytophthora infestans were regionally distributed in Europe, with populations in western Europe being dominated by clonal lineages and those in northern Europe being genetically diverse because of frequent sexual reproduction. However, since 2013 a new clonal lineage (EU_41_A2) has successfully established itself and expanded in the sexually recombining P. infestans populations of northern Europe. The objective of this study was to study phenotypic traits of the new clonal lineage of P. infestans, which may explain its successful establishment and expansion within sexually recombining populations. Fungicide sensitivity, aggressiveness, and virulence profiles of isolates of EU_41_A2 were analyzed and compared with those of the local sexual populations from Denmark, Norway, and Estonia. None of the phenotypic data obtained from the isolates collected from Denmark, Estonia, and Norway independently explained the invasive success of EU_41_A2 within sexual Nordic populations. Therefore, we hypothesize that the expansion of this new genotype could result from a combination of fitness traits and more favorable environmental conditions that have emerged in response to climate change.


Asunto(s)
Phytophthora infestans , Solanum tuberosum , Genotipo , Fenotipo , Phytophthora infestans/genética , Enfermedades de las Plantas
2.
Plant Dis ; 105(11): 3407-3417, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34003038

RESUMEN

Cyprus is the southernmost island country of Europe, located in the Mediterranean. Despite its limited area, potato production is considered an integral source of the national agricultural revenue. During 2010-2012, a late blight epidemic period for the country, the population structure of Phytophthora infestans was analyzed via a sample of 539 isolates collected from all of the main potato-cultivating regions of Cyprus. We determined mating type, mefenoxam sensitivity, and genetic polymorphism at 12 simple sequence repeat (SSRs) loci. Although both mating types were detected in the country, a gradual but dynamic shift toward A2 dominance was manifested over time. The pathogen population also demonstrated reduced sensitivity to the phenylamide fungicide, since 96.2% of the tested isolates had high (70.3%) and intermediate (25.9%) resistance to mefenoxam, which suggests that it should be replaced with other active ingredients in local disease management strategies. The genotypic analysis also revealed the predominance of the highly aggressive mefenoxam-insensitive EU_13_A2 lineage across the country, with a frequency of 79.2%. Other samples comprised an older lineage EU_2_A1 (19.5%), a very low proportion of EU_23_A1 (0.37%), and others that did not match any known lineage (0.92%). SSRs data supported triploid genomes among the dominant lineages, and patterns of their asexual population history were also apparent. A high subclonal variation of the 13_A2 population was detected, which suggested introduction events of this widespread genotype to Cyprus from major tuber-exporting countries. Present data indicate the severe impact of inoculum migration to the structure of the local population; thus, current phytosanitary procedures should be reconsidered and possibly attuned. This is the first comprehensive study to elucidate the diversity of P. infestans in Cyprus and could serve as a baseline for future monitoring of this highly adaptive plant pathogen, given that late blight management strategies should be constantly refined according to the traits of the dominant genotypes of P. infestans.


Asunto(s)
Phytophthora infestans , Solanum tuberosum , Chipre , Phytophthora infestans/genética , Enfermedades de las Plantas , Tubérculos de la Planta
3.
J Thorac Cardiovasc Surg ; 160(2): 601-605, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32689703

RESUMEN

The extraordinary demands of managing the COVID-19 pandemic has disrupted the world's ability to care for patients with thoracic malignancies. As a hospital's COVID-19 population increases and hospital resources are depleted, the ability to provide surgical care is progressively restricted, forcing surgeons to prioritize among their cancer populations. Representatives from multiple cancer, surgical, and research organizations have come together to provide a guide for triaging patients with thoracic malignancies as the impact of COVID-19 evolves as each hospital.


Asunto(s)
Betacoronavirus/patogenicidad , Infecciones por Coronavirus/terapia , Prestación Integrada de Atención de Salud/organización & administración , Neumonía Viral/terapia , Neoplasias Torácicas/cirugía , Procedimientos Quirúrgicos Torácicos , Triaje/organización & administración , COVID-19 , Toma de Decisiones Clínicas , Consenso , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/virología , Necesidades y Demandas de Servicios de Salud/organización & administración , Interacciones Microbiota-Huesped , Humanos , Evaluación de Necesidades/organización & administración , Salud Laboral , Pandemias , Seguridad del Paciente , Selección de Paciente , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Neumonía Viral/virología , Medición de Riesgo , Factores de Riesgo , SARS-CoV-2 , Neoplasias Torácicas/epidemiología , Procedimientos Quirúrgicos Torácicos/efectos adversos , Tiempo de Tratamiento
4.
Artículo en Inglés | MEDLINE | ID: mdl-32384731

RESUMEN

Tobacco treatment is increasingly recognized as important to cancer care, but few cancer centers have implemented sustainable tobacco treatment programs. The University of California Davis Comprehensive Cancer Center (UCD CCC) was funded to integrate tobacco treatment into cancer care. Lessons learned from the UCD CCC are illustrated across a systems framework with the Cancer Care Continuum and by applying constructs from the Consolidated Framework for Implementation Research. Findings demonstrate different motivational drivers for the cancer center and the broader health system. Implementation readiness across the domains of the Cancer Care Continuum with clinical entities was more mature in the Prevention domain, but Screening, Diagnosis, Treatment, and Survivorship domains demonstrated less implementation readiness despite leadership engagement. Over a two-year implementation process, the UCD CCC focused on enhancing information and knowledge sharing within the treatment domain with the support of the cancer committee infrastructure, while identifying available resources and adapting workflows for various cancer care service lines. The UCD CCC findings, while it may not be generalizable to all cancer centers, demonstrate the application of conceptual frameworks to accelerate implementation for a sustainable tobacco treatment program. Key common elements that may be shared across oncology settings include a state quitline for an adaptable intervention, cancer committees for outer/inner setting infrastructure, tobacco quality metrics for data reporting, and non-physician staff for integrated services.


Asunto(s)
Continuidad de la Atención al Paciente , Neoplasias , Tabaquismo , Implementación de Plan de Salud , Humanos , Neoplasias/complicaciones , Análisis de Sistemas , Nicotiana , Tabaquismo/complicaciones , Tabaquismo/terapia
5.
Sci Rep ; 8(1): 4429, 2018 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-29535313

RESUMEN

The population structure of the Phytophthora infestans populations that caused the recent 2013-14 late blight epidemic in eastern India (EI) and northeastern India (NEI) was examined. The data provide new baseline information for populations of P. infestans in India. A migrant European 13_A2 genotype was responsible for the 2013-14 epidemic, replacing the existing populations. Mutations have generated substantial sub-clonal variation with 24 multi-locus genotypes (MLGs) found, of which 19 were unique variants not yet reported elsewhere globally. Samples from West Bengal were the most diverse and grouped alongside MLGs found in Europe, the UK and from neighbouring Bangladesh but were not linked directly to most samples from south India. The pathogen population was broadly more aggressive on potato than on tomato and resistant to the fungicide metalaxyl. Pathogen population diversity was higher in regions around the international borders with Bangladesh and Nepal. Overall, the multiple shared MLGs suggested genetic contributions from UK and Europe in addition to a sub-structure based on the geographical location within India. Our data indicate the need for improved phytosanitary procedures and continuous surveillance to prevent the further introduction of aggressive lineages of P. infestans into the country.


Asunto(s)
Tipificación de Secuencias Multilocus/métodos , Phytophthora infestans/clasificación , Enfermedades de las Plantas/parasitología , Solanum tuberosum/parasitología , Epidemias , Europa (Continente) , Evolución Molecular , India , Filogenia , Filogeografía , Phytophthora infestans/genética , Phytophthora infestans/patogenicidad , Análisis de Secuencia de ADN/métodos , Reino Unido
6.
Ann Thorac Surg ; 104(6): 1798-1804, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29074150

RESUMEN

BACKGROUND: The National Comprehensive Cancer Network recommends adjuvant chemotherapy (AC) for patients with completely resected (R0) pT3N0M0 non-small cell lung cancer (NSCLC) with chest wall invasion. There is minimal evidence to support this recommendation. We aimed to determine whether there is a survival benefit with AC and if so whether it depends on tumor size. METHODS: Patients who had undergone R0 resection for pT3N0M0 NSCLC with chest wall invasion were identified in the National Cancer Data Base from 2008 to 2012. Multivariable Cox proportional hazards modeling was used to determine independent predictors of overall mortality. RESULTS: Of 247 patients, 92 (37.3%) received AC. The median tumor size without AC was 42 mm (interquartile range [IQR], 30 to 60 mm) and with AC was 56 mm (IQR, 40 to 70 mm; p = 0.003). Median follow-up was 21.7 months (IQR, 10.6 to 29.1 months). There was no difference in AC based on tumor grade, but the 3-year overall survival for those with well-differentiated or moderately differentiated tumors was 68% versus 55% in those with poorly differentiated or undifferentiated tumors. Three-year overall survival for the entire cohort was 59%. There was no difference in overall survival between those who received AC and those who did not. The only significant predictor of mortality in both univariable and multivariable analyses was poorly or undifferentiated tumor grade. CONCLUSIONS: For patients with pT3N0M0 NSCLC with chest wall invasion there is no survival benefit with AC, regardless of tumor size or grade, after R0 resection. Poorly differentiated or undifferentiated tumor grade is an independent predictor of mortality.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Quimioterapia Adyuvante , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Neumonectomía , Anciano , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estudios Retrospectivos , Tasa de Supervivencia , Pared Torácica/patología
7.
Fungal Biol ; 121(5): 467-477, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28390504

RESUMEN

A total of 161 Phytophthora infestans isolates, collected from infected potato and tomato plants during 2008-2014, were characterized based on mating type, metalaxyl sensitivity and polymorphism at 12 simple sequence repeat (SSR) loci, in order to investigate the population of P. infestans in the north-west of Algeria, an emerging potato production region. The majority of isolates were of A2 mating type (112 isolates). A high percentage (89 %) of resistance to metalaxyl among isolates was detected. The metalaxyl resistant phenotype was present in both mating types with a higher percentage in A2 mating type isolates. SSR-based genotypic analysis of P. infestans population showed a low diversity. Genotype 13_A2 was the predominant in the population with a frequency of 67 % followed by 2_A1 (21 %) and 23_A1 (5 %). Genotype 23_A1 was detected only in tomato and potato isolates collected in 2013 and 2014.


Asunto(s)
Phytophthora infestans/clasificación , Phytophthora infestans/aislamiento & purificación , Alanina/análogos & derivados , Alanina/metabolismo , Argelia , Farmacorresistencia Fúngica , Fungicidas Industriales/metabolismo , Genes del Tipo Sexual de los Hongos , Solanum lycopersicum/microbiología , Phytophthora infestans/genética , Phytophthora infestans/fisiología , Polimorfismo Genético , Solanum tuberosum/microbiología
8.
Glob Chang Biol ; 22(11): 3724-3738, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27214030

RESUMEN

The impact of climate change on dispersal processes is largely ignored in risk assessments for crop diseases, as inoculum is generally assumed to be ubiquitous and nonlimiting. We suggest that consideration of the impact of climate change on the connectivity of crops for inoculum transmission may provide additional explanatory and predictive power in disease risk assessments, leading to improved recommendations for agricultural adaptation to climate change. In this study, a crop-growth model was combined with aerobiological models and a newly developed infection risk model to provide a framework for quantifying the impact of future climates on the risk of disease occurrence and spread. The integrated model uses standard meteorological variables and can be easily adapted to various crop pathosystems characterized by airborne inoculum. In a case study, the framework was used with data defining the spatial distribution of potato crops in Scotland and spatially coherent, probabilistic climate change data to project the future connectivity of crop distributions for Phytophthora infestans (causal agent of potato late blight) inoculum and the subsequent risk of infection. Projections and control recommendations are provided for multiple combinations of potato cultivar and CO2 emissions scenario, and temporal and spatial averaging schemes. Overall, we found that relative to current climatic conditions, the risk of late blight will increase in Scotland during the first half of the potato growing season and decrease during the second half. To guide adaptation strategies, we also investigated the potential impact of climate change-driven shifts in the cropping season. Advancing the start of the potato growing season by 1 month proved to be an effective strategy from both an agronomic and late blight management perspective.


Asunto(s)
Cambio Climático , Phytophthora infestans , Solanum tuberosum , Dióxido de Carbono , Productos Agrícolas , Enfermedades de las Plantas , Riesgo , Escocia , Estaciones del Año
9.
Clin Lung Cancer ; 16(3): 165-72, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25838158

RESUMEN

New approaches to optimization of cancer drug development in the laboratory and the clinic will be required to fully achieve the goal of individualized, precision cancer therapy. Improved preclinical models that more closely reflect the now recognized genomic complexity of human cancers are needed. Here we describe a collaborative research project that integrates core resources of The Jackson Laboratory Basic Science Cancer Center with genomics and clinical research facilities at the UC Davis Comprehensive Cancer Center to establish a clinically and genomically annotated patient-derived xenograft (PDX) platform designed to enhance new drug development and strategies for targeted therapies. Advanced stage non-small-cell lung cancer (NSCLC) was selected for initial studies because of emergence of a number of "druggable" molecular targets, and recent recognition of substantial inter- and intrapatient tumor heterogeneity. Additionally, clonal evolution after targeted therapy interventions make this tumor type ideal for investigation of this platform. Using the immunodeficient NOD scid gamma mouse, > 200 NSCLC tumor biopsies have been xenotransplanted. During the annotation process, patient tumors and subsequent PDXs are compared at multiple levels, including histomorphology, clinically applicable molecular biomarkers, global gene expression patterns, gene copy number variations, and DNA/chromosomal alterations. NSCLC PDXs are grouped into panels of interest according to oncogene subtype and/or histologic subtype. Multiregimen drug testing, paired with next-generation sequencing before and after therapy and timed tumor pharmacodynamics enables determination of efficacy, signaling pathway alterations, and mechanisms of sensitivity-resistance in individual models. This approach should facilitate derivation of new therapeutic strategies and the transition to individualized therapy.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Genómica , Neoplasias Pulmonares/genética , Ensayos Antitumor por Modelo de Xenoinjerto/métodos , Animales , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Ratones , Ratones Endogámicos NOD , Ratones SCID
10.
Proc Natl Acad Sci U S A ; 111(24): 8791-6, 2014 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-24889615

RESUMEN

Phytophthora infestans is a destructive plant pathogen best known for causing the disease that triggered the Irish potato famine and remains the most costly potato pathogen to manage worldwide. Identification of P. infestan's elusive center of origin is critical to understanding the mechanisms of repeated global emergence of this pathogen. There are two competing theories, placing the origin in either South America or in central Mexico, both of which are centers of diversity of Solanum host plants. To test these competing hypotheses, we conducted detailed phylogeographic and approximate Bayesian computation analyses, which are suitable approaches to unraveling complex demographic histories. Our analyses used microsatellite markers and sequences of four nuclear genes sampled from populations in the Andes, Mexico, and elsewhere. To infer the ancestral state, we included the closest known relatives Phytophthora phaseoli, Phytophthora mirabilis, and Phytophthora ipomoeae, as well as the interspecific hybrid Phytophthora andina. We did not find support for an Andean origin of P. infestans; rather, the sequence data suggest a Mexican origin. Our findings support the hypothesis that populations found in the Andes are descendants of the Mexican populations and reconcile previous findings of ancestral variation in the Andes. Although centers of origin are well documented as centers of evolution and diversity for numerous crop plants, the number of plant pathogens with a known geographic origin are limited. This work has important implications for our understanding of the coevolution of hosts and pathogens, as well as the harnessing of plant disease resistance to manage late blight.


Asunto(s)
Evolución Molecular , Phytophthora infestans/genética , Solanum tuberosum/parasitología , Algoritmos , Teorema de Bayes , Colombia , Ecuador , Genotipo , Geografía , Historia del Siglo XIX , Humanos , Irlanda , México , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Perú , Filogenia , Enfermedades de las Plantas/historia , Análisis de Componente Principal , Inanición/historia
11.
Philos Trans R Soc Lond B Biol Sci ; 369(1639): 20130087, 2014 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-24535396

RESUMEN

Essentially all plant species exhibit heritable genetic variation for resistance to a variety of plant diseases caused by fungi, bacteria, oomycetes or viruses. Disease losses in crop monocultures are already significant, and would be greater but for applications of disease-controlling agrichemicals. For sustainable intensification of crop production, we argue that disease control should as far as possible be achieved using genetics rather than using costly recurrent chemical sprays. The latter imply CO2 emissions from diesel fuel and potential soil compaction from tractor journeys. Great progress has been made in the past 25 years in our understanding of the molecular basis of plant disease resistance mechanisms, and of how pathogens circumvent them. These insights can inform more sophisticated approaches to elevating disease resistance in crops that help us tip the evolutionary balance in favour of the crop and away from the pathogen. We illustrate this theme with an account of a genetically modified (GM) blight-resistant potato trial in Norwich, using the Rpi-vnt1.1 gene isolated from a wild relative of potato, Solanum venturii, and introduced by GM methods into the potato variety Desiree.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Productos Agrícolas/genética , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitología , Enfermedades de las Plantas/virología , Plantas Modificadas Genéticamente/genética , Clonación Molecular/métodos , Modelos Biológicos , Solanum tuberosum/genética , Solanum tuberosum/microbiología
12.
Elife ; 2: e00954, 2013 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-23795302

RESUMEN

Large-scale DNA sequencing of samples of foliage collected in the 19th century from plants infected with late blight has shown that the potato famines of the 1840s were triggered by a single clonal lineage of Phytophthora infestans, called HERB-1, which persisted for at least 50 years.


Asunto(s)
Phytophthora infestans/patogenicidad , Solanum tuberosum/microbiología , Inanición , Humanos
13.
PLoS Pathog ; 8(10): e1002940, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23055926

RESUMEN

Pest and pathogen losses jeopardise global food security and ever since the 19(th) century Irish famine, potato late blight has exemplified this threat. The causal oomycete pathogen, Phytophthora infestans, undergoes major population shifts in agricultural systems via the successive emergence and migration of asexual lineages. The phenotypic and genotypic bases of these selective sweeps are largely unknown but management strategies need to adapt to reflect the changing pathogen population. Here, we used molecular markers to document the emergence of a lineage, termed 13_A2, in the European P. infestans population, and its rapid displacement of other lineages to exceed 75% of the pathogen population across Great Britain in less than three years. We show that isolates of the 13_A2 lineage are among the most aggressive on cultivated potatoes, outcompete other aggressive lineages in the field, and overcome previously effective forms of plant host resistance. Genome analyses of a 13_A2 isolate revealed extensive genetic and expression polymorphisms particularly in effector genes. Copy number variations, gene gains and losses, amino-acid replacements and changes in expression patterns of disease effector genes within the 13_A2 isolate likely contribute to enhanced virulence and aggressiveness to drive this population displacement. Importantly, 13_A2 isolates carry intact and in planta induced Avrblb1, Avrblb2 and Avrvnt1 effector genes that trigger resistance in potato lines carrying the corresponding R immune receptor genes Rpi-blb1, Rpi-blb2, and Rpi-vnt1.1. These findings point towards a strategy for deploying genetic resistance to mitigate the impact of the 13_A2 lineage and illustrate how pathogen population monitoring, combined with genome analysis, informs the management of devastating disease epidemics.


Asunto(s)
Genoma Fúngico , Phytophthora infestans/genética , Phytophthora infestans/patogenicidad , Enfermedades de las Plantas/microbiología , Solanum tuberosum/microbiología , Productos Agrícolas/microbiología , Variaciones en el Número de Copia de ADN , Perfilación de la Expresión Génica , Genes de Plantas , Interacciones Huésped-Patógeno , Inmunidad Innata , Proteínas de Plantas/genética , Polimorfismo Genético , Análisis de Secuencia de ADN
14.
New Phytol ; 191(3): 763-776, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21539575

RESUMEN

• A detailed molecular understanding of how oomycete plant pathogens evade disease resistance is essential to inform the deployment of durable resistance (R) genes. • Map-based cloning, transient expression in planta, pathogen transformation and DNA sequence variation across diverse isolates were used to identify and characterize PiAVR2 from potato late blight pathogen Phytophthora infestans. • PiAVR2 is an RXLR-EER effector that is up-regulated during infection, accumulates at the site of haustoria formation, and is recognized inside host cells by potato protein R2. Expression of PiAVR2 in a virulent P. infestans isolate conveys a gain-of-avirulence phenotype, indicating that this is a dominant gene triggering R2-dependent disease resistance. PiAVR2 presence/absence polymorphisms and differential transcription explain virulence on R2 plants. Isolates infecting R2 plants express PiAVR2-like, which evades recognition by R2. PiAVR2 and PiAVR2-like differ in 13 amino acids, eight of which are in the C-terminal effector domain; one or more of these determines recognition by R2. Nevertheless, few polymorphisms were observed within each gene in pathogen isolates, suggesting limited selection pressure for change within PiAVR2 and PiAVR2-like. • Our results direct a search for R genes recognizing PiAVR2-like, which, deployed with R2, may exert strong selection pressure against the P. infestans population.


Asunto(s)
Phytophthora infestans/patogenicidad , Enfermedades de las Plantas/inmunología , Polimorfismo Genético/genética , Proteínas/metabolismo , Solanum tuberosum/fisiología , Secuencia de Aminoácidos , Mapeo Cromosómico , Clonación Molecular , Regulación de la Expresión Génica , Genes Dominantes/genética , Genes de Plantas/genética , Datos de Secuencia Molecular , Phytophthora infestans/genética , Phytophthora infestans/inmunología , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta/genética , Hojas de la Planta/genética , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Hojas de la Planta/fisiología , Estructura Terciaria de Proteína , Proteínas/genética , Solanum/genética , Solanum tuberosum/genética , Solanum tuberosum/inmunología , Solanum tuberosum/microbiología , Virulencia/genética , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
15.
Healthc Financ Manage ; 60(10): 100-2, 104, 106 passim, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17040037

RESUMEN

Beyond budgeting transcends the limitations of traditional budgeting by replacing fixed financial targets with targets based on key performance indicators. For Park Nicollet Health Services, the decision to implement beyond budgeting coincided with a larger move to adopt a Lean approach to management. Park Nicollet's process to implement beyond budgeting-from submission of the initial proposal through two test runs with process refinements to full implementation-lasted about one year, from January 2005 to January 2006.


Asunto(s)
Presupuestos/organización & administración , Prestación Integrada de Atención de Salud/economía , Administración Financiera de Hospitales/organización & administración , Minnesota , Estudios de Casos Organizacionales
16.
Mol Plant Pathol ; 7(5): 365-79, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20507453

RESUMEN

SUMMARY New species of Phytophthora such as Phytophthora ramorum, P. kernoviae and P. quercina together with P. citricola are plant pathogens which impact on forest health, natural ecosystem stability and international trade. A real-time multiplex PCR approach based on TaqMan PCR was developed to simultaneously identify and detect these four Phytophthora species. Specific primers and probes labelled with FAM (P. ramorum), Yakima Yellow (P. kernoviae), Rox (P. citricola) and Cy5 (P. quercina) were designed in different regions of the ras-related protein (Ypt1) gene. A new set of Black Hole Quenchers (BHQ), which dissipate energy as heat rather than fluorescence, were utilized. The method proved to be highly specific in tests with target DNA from 72 Phytophthora isolates (35 species). For all pathogens, the detection limit was 100 fg of target DNA and was not improved utilizing a nested approach to provide a first round of amplification with Phytophthora spp.-specific primers. Cycle threshold (Ct) values were linearly correlated with the concentration of the target DNA (correlation coefficients ranged from 0.947 to 0.996) and were not affected by the presence of plant extracts, indicating the appropriateness of the method for qualitative and quantitative analyses. Two universal primers and a TaqMan probe were also developed to evaluate the quality and quantity of extracted DNA and to avoid false negatives. The reliability of the entire procedure was assessed using both artificially and naturally infected leaves of a range of plant species. The method, combined with a rapid procedure for DNA extraction, proved to be rapid, reliable, sensitive and cost effective as multiple pathogens were detected within the same plant extract by using different primer/probe combinations.

17.
Biotechnol Prog ; 19(6): 1792-7, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14656158

RESUMEN

A method to quantify the indigo precursor indican (indoxyl-beta-D-glucoside) in Polygonum tinctorium L. has been developed. Plant material was extracted in deionized water, and indican was identified and quantified using high performance liquid chromatography (HPLC) coupled to an evaporative light scattering detector (ELSD). Results confirmed that with this method it is possible to measure indican content in a short time, obtaining reliable and reproducible data. Using this method, leaf indican content was quantified every 15 days during the growing season (from May to October) in P. tinctorium crops grown in a field experiment in Central Italy. Results showed that indican increased along the growing season until flowering and was positively affected by photosynthetic active radiation (PAR). Indican is naturally hydrolyzed by native beta-glucosidase to indoxyl and glucose, the indoxyl yielding indigo. The activity of two enzymes, sweet almond beta-glucosidase and Novarom G preparation, were compared with P. tinctorium native beta-glucosidase to evaluate indigo production. Results showed that the ability to promote indigo formation increased as follows: almond beta-glucosidase

Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Indicán/metabolismo , Indoles/metabolismo , Fotometría/métodos , Polygonum/metabolismo , beta-Glucosidasa/metabolismo , Hidrólisis , Indicán/análisis , Carmin de Índigo , Extractos Vegetales/análisis , Hojas de la Planta/metabolismo , Reproducibilidad de los Resultados , Estaciones del Año , Sensibilidad y Especificidad , beta-Glucosidasa/análisis
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