Razas de Rhizoctonia solani Kuhn en fríjol.

Se efectuó un estudio para definir la existencia de distintas razas de Rhizoctonia solani en fríjol en Colombia. El hongo se aisló de plantas de fríjol común (Phaseolus vulgaris), fríjol lima (P. lumatus) y caupí (Vigna sinensis), recolectadas en el valle de Medellín (Antioquia). Se utilizaron varios medios de cultivo a saber: papa-dextrosa-agar (PDA), papa-dextrosa-peptona (PDP), papa-dextrosa-agar-zumo de hojas de fríjol (PDAF), agar-frijol lima (AFL), harina de maíz-agar (NMA), agar simple (AS) y granos de trigo al 100 por ciento de humedad. Para las pruebas de patogenicidad, se inoculó el suelo con la cantidad de hongo que había crecido durante una semana en el medio de granos de trigo. Luego se sembraron las semillas, previamente desinfectadas, a una profunidad de 3 centímetros. Además se determinaron las características de crecimiento y fisiología del hongo. Se determinaron 3 razas de esta patógeno: la raza A fué severamente patógena en fríjol lima y caupí, la raza B fué moderadamente patógena en fríjol y altamente virulenta en fríjol lima y caupí, y la raza C fué débilmente patógena y fríjol y caupí, pero altamente virulenta en fríjol lima. La clasificación de estas tres razas de R. solani se basa en patogonicidad, fisiología y morfología.Fríjol-Phaseolus vulgari

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen

Genomic and phenotypic insights from an atlas of genetic effects on DNA methylation

DNA methylation quantitative trait locus (mQTL) analyses on 32,851 participants identify genetic variants associated with DNA methylation at 420,509 sites in blood, resulting in a database of >270,000 independent mQTLs.Characterizing genetic influences on DNA methylation (DNAm) provides an opportunity to understand mechanisms underpinning gene regulation and disease. In the present study, we describe results of DNAm quantitative trait locus (mQTL) analyses on 32,851 participants, identifying genetic variants associated with DNAm at 420,509 DNAm sites in blood. We present a database of >270,000 independent mQTLs, of which 8.5% comprise long-range (trans) associations. Identified mQTL associations explain 15-17% of the additive genetic variance of DNAm. We show that the genetic architecture of DNAm levels is highly polygenic. Using shared genetic control between distal DNAm sites, we constructed networks, identifying 405 discrete genomic communities enriched for genomic annotations and complex traits. Shared genetic variants are associated with both DNAm levels and complex diseases, but only in a minority of cases do these associations reflect causal relationships from DNAm to trait or vice versa, indicating a more complex genotype-phenotype map than previously anticipated.Molecular Epidemiolog