Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Eur J Pediatr ; 179(1): 141-149, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31691849

RESUMEN

Three suitable compounds (morphine, chlorpromazine, and phenobarbital) to treat neonatal abstinence syndrome were compared in a prospective multicenter, double-blind trial. Neonates exposed to opioids in utero were randomly allocated to one of three treatment groups. When a predefined threshold of a modified Finnegan score was reached, treatment started and increased stepwise until symptoms were controlled. If symptoms could not be controlled with the predefined maximal dose of a single drug, a second drug was added. Among 143 infants recruited, 120 needed pharmacological treatment. Median length of treatment for morphine was 22 days (95% CI 18 to 33), for chlorpromazine 25 days (95% CI 21 to 34), and for phenobarbital 32 days (95% CI 27 to 38) (p = ns). In the morphine group, only 3% of infants (1/33) needed a second drug; in the chlorpromazine group, this proportion was 56% (24/43), and in the phenobarbital group 30% (13/44).Conclusion: None of the drugs tested for treating neonatal abstinence syndrome resulted in a significantly shorter treatment length than the others. As morphine alone was able to control symptoms in almost all infants, it may be preferred to the two other drugs but should still be tested against more potent opioids such as buprenorphine.Trial registration: At ClinicalTrials.gov NCT02810782 (registered retrospectively).What is Known:• Neonates exposed to opiates in utero and presenting with withdrawal symptoms should first be treated by non-pharmacological supportive measures.• In those who fail, drugs have to be given, but there is controversy which drug is best.What is New:• Among three candidates, morphine, chlorpromazine and phenobarbital, none resulted in significantly shorter treatment time.• As morphine alone was able to control symptoms in almost all infants, it may be preferred to the two other drugs.


Asunto(s)
Analgésicos Opioides/efectos adversos , Clorpromazina/uso terapéutico , Antagonistas de Dopamina/uso terapéutico , Hipnóticos y Sedantes/uso terapéutico , Morfina/uso terapéutico , Síndrome de Abstinencia Neonatal/tratamiento farmacológico , Fenobarbital/uso terapéutico , Analgésicos Opioides/uso terapéutico , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Masculino , Estudios Prospectivos , Resultado del Tratamiento
2.
F1000Res ; 7: 1141, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30271584

RESUMEN

Subpopulation identification, usually via some form of unsupervised clustering, is a fundamental step in the analysis of many single-cell RNA-seq data sets. This has motivated the development and application of a broad range of clustering methods, based on various underlying algorithms. Here, we provide a systematic and extensible performance evaluation of 14 clustering algorithms implemented in R, including both methods developed explicitly for scRNA-seq data and more general-purpose methods. The methods were evaluated using nine publicly available scRNA-seq data sets as well as three simulations with varying degree of cluster separability. The same feature selection approaches were used for all methods, allowing us to focus on the investigation of the performance of the clustering algorithms themselves. We evaluated the ability of recovering known subpopulations, the stability and the run time and scalability of the methods. Additionally, we investigated whether the performance could be improved by generating consensus partitions from multiple individual clustering methods. We found substantial differences in the performance, run time and stability between the methods, with SC3 and Seurat showing the most favorable results. Additionally, we found that consensus clustering typically did not improve the performance compared to the best of the combined methods, but that several of the top-performing methods already perform some type of consensus clustering. All the code used for the evaluation is available on GitHub ( https://github.com/markrobinsonuzh/scRNAseq_clustering_comparison). In addition, an R package providing access to data and clustering results, thereby facilitating inclusion of new methods and data sets, is available from Bioconductor ( https://bioconductor.org/packages/DuoClustering2018).

3.
BMC Genomics ; 17(1): 1015, 2016 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-27938347

RESUMEN

BACKGROUND: Whereas an increasing number of pathogenic and mutualistic ascomycetous species were sequenced in the past decade, species showing a seemingly neutral association such as root endophytes received less attention. In the present study, the genome of Phialocephala subalpina, the most frequent species of the Phialocephala fortinii s.l. - Acephala applanata species complex, was sequenced for insight in the genome structure and gene inventory of these wide-spread root endophytes. RESULTS: The genome of P. subalpina was sequenced using Roche/454 GS FLX technology and a whole genome shotgun strategy. The assembly resulted in 205 scaffolds and a genome size of 69.7 Mb. The expanded genome size in P. subalpina was not due to the proliferation of transposable elements or other repeats, as is the case with other ascomycetous genomes. Instead, P. subalpina revealed an expanded gene inventory that includes 20,173 gene models. Comparative genome analysis of P. subalpina with 13 ascomycetes shows that P. subalpina uses a versatile gene inventory including genes specific for pathogens and saprophytes. Moreover, the gene inventory for carbohydrate active enzymes (CAZymes) was expanded including genes involved in degradation of biopolymers, such as pectin, hemicellulose, cellulose and lignin. CONCLUSIONS: The analysis of a globally distributed root endophyte allowed detailed insights in the gene inventory and genome organization of a yet largely neglected group of organisms. We showed that the ubiquitous root endophyte P. subalpina has a broad gene inventory that links pathogenic and saprophytic lifestyles.


Asunto(s)
Ascomicetos/genética , Endófitos/genética , Raíces de Plantas/microbiología , Ascomicetos/metabolismo , Ascomicetos/ultraestructura , Biología Computacional/métodos , Elementos Transponibles de ADN , Endófitos/metabolismo , Endófitos/ultraestructura , Ontología de Genes , Transferencia de Gen Horizontal , Genes Fúngicos , Genoma Fúngico , Genómica/métodos , Familia de Multigenes , Interferencia de ARN , Secuencias Repetitivas de Ácidos Nucleicos , Metabolismo Secundario/genética
4.
BMC Genomics ; 13: 166, 2012 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-22559219

RESUMEN

BACKGROUND: Mitochondrial (mt) markers are successfully applied in evolutionary biology and systematics because mt genomes often evolve faster than the nuclear genomes. In addition, they allow robust phylogenetic analysis based on conserved proteins of the oxidative phosphorylation system. In the present study we sequenced and annotated the complete mt genome of P. subalpina, a member of the Phialocephala fortinii s.l. - Acephala applanata species complex (PAC). PAC belongs to the Helotiales, which is one of the most diverse groups of ascomycetes including more than 2,000 species. The gene order was compared to deduce the mt genome evolution in the Pezizomycotina. Genetic variation in coding and intergenic regions of the mtDNA was studied for PAC to assess the usefulness of mt DNA for species diagnosis. RESULTS: The mt genome of P. subalpina is 43,742 bp long and codes for 14 mt genes associated with the oxidative phosphorylation. In addition, a GIY-YIG endonuclease, the ribosomal protein S3 (Rps3) and a putative N-acetyl-transferase were recognized. A complete set of tRNA genes as well as the large and small rRNA genes but no introns were found. All protein-coding genes were confirmed by EST sequences. The gene order in P. subalpina deviated from the gene order in Sclerotinia sclerotiorum, the only other helotialean species with a fully sequenced and annotated mt genome. Gene order analysis within Pezizomycotina suggests that the evolution of gene orders is mostly driven by transpositions. Furthermore, sequence diversity in coding and non-coding mtDNA regions in seven additional PAC species was pronounced and allowed for unequivocal species diagnosis in PAC. CONCLUSIONS: The combination of non-interrupted ORFs and EST sequences resulted in a high quality annotation of the mt genome of P. subalpina, which can be used as a reference for the annotation of other mt genomes in the Helotiales. In addition, our analyses show that mtDNA loci will be the marker of choice for future analysis of PAC communities.


Asunto(s)
Ascomicetos/genética , Evolución Molecular , Genoma Fúngico/genética , Genoma Mitocondrial/genética , Secuencia Conservada/genética , ADN Mitocondrial/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Duplicación de Gen/genética , Orden Génico/genética , Reordenamiento Génico/genética , Sitios Genéticos/genética , Marcadores Genéticos , Sistemas de Lectura Abierta/genética , Filogenia , Polimorfismo Genético , Alineación de Secuencia , Especificidad de la Especie , Transcriptoma/genética
5.
BMC Evol Biol ; 11: 282, 2011 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-21961933

RESUMEN

BACKGROUND: Fungi are asexually and sexually reproducing organisms that can combine the evolutionary advantages of the two reproductive modes. However, for many fungi the sexual cycle has never been observed in the field or in vitro and it remains unclear whether sexual reproduction is absent or cryptic. Nevertheless, there are indirect approaches to assess the occurrence of sex in a species, such as population studies, expression analysis of genes involved in mating processes and analysis of their selective constraints. The members of the Phialocephala fortinii s. l. - Acephala applanata species complex (PAC) are ascomycetes and the predominant dark septate endophytes that colonize woody plant roots. Despite their abundance in many ecosystems of the northern hemisphere, no sexual state has been identified to date and little is known about their reproductive biology, and how it shaped their evolutionary history and contributes to their ecological role in forest ecosystems. We therefore aimed at assessing the importance of sexual reproduction by indirect approaches that included molecular analyses of the mating type (MAT) genes involved in reproductive processes. RESULTS: The study included 19 PAC species and > 3, 000 strains that represented populations from different hosts, continents and ecosystems. Whereas A. applanata had a homothallic (self-fertile) MAT locus structure, all other species were structurally heterothallic (self-sterile). Compatible mating types were observed to co-occur more frequently than expected by chance. Moreover, in > 80% of the populations a 1:1 mating type ratio and gametic equilibrium were found. MAT genes were shown to evolve under strong purifying selection. CONCLUSIONS: The signature of sex was found in worldwide populations of PAC species and functionality of MAT genes is likely preserved by purifying selection. We hypothesize that cryptic sex regularely occurs in the PAC and that further field studies and in vitro crosses will lead to the discovery of the sexual state. Although structurally heterothallic species prevail, it cannot be excluded that homothallism represents the ancestral breeding system in the PAC.


Asunto(s)
Ascomicetos/genética , Ascomicetos/fisiología , Demografía , Evolución Molecular , Genes del Tipo Sexual de los Hongos/genética , Secuencia de Bases , Cartilla de ADN/genética , Genética de Población , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Reproducción/genética , Reproducción/fisiología , Selección Genética , Análisis de Secuencia de ADN
6.
Fungal Genet Biol ; 47(9): 761-72, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20541616

RESUMEN

Members of the Phialocephala fortinii sensu lato -Acephala applanata species complex (PAC) are the dominant root endophytes of woody plants in temperate and boreal forests. In the present study, the mating type (MAT) idiomorphs of eight species belonging to the PAC were cloned. Because direct cloning of MAT idiomorphs was not possible, species phylogenetically placed between the PAC and other helotialean species with characterized MAT locus were used for an intermediate cloning step. Whereas A. applanata showed a homothallic organization structure of the MAT locus, all other species either contained the MAT1-1 or MAT1-2 idiomorph indicative of heterothallism. A Tc1-like transposable element was found within the MAT locus of A. applanata. Analysis of A. applanata strains collected over a broad geographical range showed that the transposable element was present in all A. applanata strains, suggesting an ancient transposition event. Moreover, a partial MAT1-1-1 gene was identified within MAT1-2 idiomorphs, a common phenomenon in the order Helotiales. However, this partial gene was not fixed in all populations of the species. The evolution of the MAT locus with regard to different mating systems is discussed for the species complex.


Asunto(s)
Ascomicetos/genética , Proteínas Fúngicas/genética , Genes del Tipo Sexual de los Hongos , Secuencia de Aminoácidos , Ascomicetos/química , Ascomicetos/clasificación , Ascomicetos/aislamiento & purificación , Mapeo Cromosómico , Proteínas Fúngicas/química , Datos de Secuencia Molecular , Filogenia , Picea/microbiología , Pinus/microbiología , Alineación de Secuencia , Árboles/microbiología , Vaccinium/microbiología
7.
Mycol Res ; 113(Pt 2): 207-21, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19015028

RESUMEN

Dark, septate endophytes (DSE) were isolated from roots and needles of dwarf Picea abies and from roots of Vaccinium spp. growing on a permafrost site in the Jura Mountains in Switzerland. Two of the isolates sporulated after incubation for more than one year at 4 degrees C. One of them was a hitherto undescribed helotialean ascomycete Phaeomollisia piceae gen. sp. nov., the other was a new species of Phialocephala, P. glacialis sp. nov. Both species are closely related to DSE of the Phialocephala fortinii s. lat.-Acephala applanata species complex (PAC) as revealed by phylogenetic analyses of the ITS and 18S rDNA regions. Morphologically dissimilar fungi, such as Vibrissea and Loramyces species, are phylogenetically also closely linked to the new species and the PAC. Cadophora lagerbergii and C. (Phialophora) botulispora are moved to Phialocephala because Phialocephala dimorphospora and P. repens are the closest relatives. Several Mollisia species were closely related to the new species and the PAC according to ITS sequence comparisons. One DSE from needles of Abies alba and one from shoots of Castanea sativa formed Cystodendron anamorphs in culture. Their identical 18S sequences and almost identical ITS sequences indicated Mollisia species as closest relatives, suggesting that Mollisia species are highly euryoecious.


Asunto(s)
Ascomicetos/genética , Filogenia , Picea/microbiología , Ascomicetos/clasificación , Ascomicetos/crecimiento & desarrollo , Ascomicetos/aislamiento & purificación , ADN de Hongos/genética , ADN Ribosómico/genética , ADN Espaciador Ribosómico/genética , Hojas de la Planta/microbiología , Raíces de Plantas/microbiología , Análisis de Secuencia de ADN
8.
Mycologia ; 100(1): 47-67, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18488352

RESUMEN

Phialocephala fortinii s.1. and Acephala applanata are the dominant dark septate endophytes (DSE) in roots of many trees and shrubs. Population genetic analysis led to the discovery of morphologically indistinguishable but reproductively isolated cryptic species (CSP) within Phialocephala fortinii s.1. In the present study we show that sequence data of two coding (beta-tubulin and translation elongation factor [EF-lalpha]) and three noncoding DNA loci confirm subdivision of P. fortinii s.1. and allow to differentiate seven CSP of P. fortinii. In addition we show that strains collected throughout Europe can be classified correctly based on these sequence markers. Statistically significant differences in growth response on different media were observed among CSP of P. fortinii and A. applanata. Growth inhibition on MEA amended with 100 mgl(-1) cycloheximide had the strongest differential effect of all physiological traits examined. In contrast exoenzyme production (laccase, proteinase, pectinase, phenol-oxidase, amylase, cytochrome oxidase and tyrosinase) rarely helped to differentiate CSP of P. fortinii. However A. applanata was a strong producer of amylases, laccases and proteinases. Based on these data we propose to assign species rank to six CSP of P. fortinii: P. turiciensis, P. letzii, P. europaea, P. helvetica, P. uotolensis, P. subalpina spp. nov. and P. fortinii s.s.


Asunto(s)
Ascomicetos/clasificación , Ascomicetos/genética , Ascomicetos/crecimiento & desarrollo , Ascomicetos/metabolismo , Biodiversidad , Medios de Cultivo/química , ADN de Hongos/genética , Enzimas/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Datos de Secuencia Molecular , Factor 1 de Elongación Peptídica/genética , Filogenia , Raíces de Plantas/microbiología , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , Especificidad de la Especie , Esporas Fúngicas/citología , Tubulina (Proteína)/genética
9.
Mol Ecol Resour ; 8(6): 1322-5, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21586034

RESUMEN

Species of the Phialocephala fortinii s.l.-Acephala applanata complex are the dominant dark septate endophytes (DSE) in roots of species belonging to the Pinaceae. The two species Phialocephala subalpina and P. fortinii s.s. belong to the most widely distributed species within this complex. In the present study, 15 polymorphic microsatellite loci were developed for these two closely related species. Strains of a community which were analysed previously using single-copy restriction fragment length polymorphism were screened with the new markers. Microsatellites were suitable to classify the two species and to recognize individuals within species.

10.
Fungal Genet Biol ; 44(8): 773-88, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17289408

RESUMEN

Sequence data of two coding and three non-coding loci were used to study the taxonomic identity within and relatedness among seven previously defined cryptic species (CSP) of Phialocephala fortinii and Acephala applanata using two approaches of species recognition. Identification of taxonomic groups corresponding to CSP was ambiguous in some cases when applying solely the genealogical concordance phylogenetic species recognition (GCPSR) concept. The definition of groups corresponding to CSP using GCPSR was complicated due to shared sequence haplotypes between CSP, unresolved CSP for several loci, and possible introgression. GCPSR in conjunction with a population genetic approach improved resolution significantly and the CSP status could be confirmed for all seven CSP of P. fortinii s.l. The most critical step in both analyses was the definition of groups. The combination of several classes of markers differing in resolution helped to define species boundaries.


Asunto(s)
Ascomicetos/clasificación , ADN de Hongos/genética , Micología/métodos , Ascomicetos/genética , Análisis por Conglomerados , ADN de Hongos/química , Proteínas Fúngicas/genética , Genética de Población , Datos de Secuencia Molecular , Factor 1 de Elongación Peptídica/genética , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , Tubulina (Proteína)/genética
11.
Fungal Genet Biol ; 43(6): 410-21, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16631398

RESUMEN

The genetic structure of the root endophytes Phialocephala fortinii s.l. and Acephala applanata was analyzed in two undisturbed forests. A total of 606 strains isolated from surface-sterilized, fine roots of Picea abies and Vaccinium myrtillus were examined. Two new cryptic species of P. fortinii were recognized and host specialization of A. applanata was confirmed. This species was almost exclusively isolated from roots of P. abies. The index of association did not deviate significantly from zero within any population, suggesting that recombination occurs or had occurred. Significant gene but no genotype flow was detected among study sites for P. fortinii s.l. In contrast, several isolates of A. applanata with both identical multi-locus haplotype and identical ISSR fingerprint were found in both study sites indicating genotype flow or a recent common history.


Asunto(s)
Ascomicetos/genética , Flujo Génico , Árboles/microbiología , Ascomicetos/clasificación , Ascomicetos/crecimiento & desarrollo , Genética de Población , Picea/microbiología , Raíces de Plantas/microbiología , Suiza , Vaccinium myrtillus/microbiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...