Interaction of plant growth regulators and reactive oxygen species to regulate petal senescence in wallflowers (Erysimum linifolium)

Background In many species floral senescence is coordinated by ethylene. Endogenous levels rise, and exogenous application accelerates senescence. Furthermore, floral senescence is often associated with increased reactive oxygen species, and is delayed by exogenously applied cytokinin. However, how these processes are linked remains largely unresolved. Erysimum linifolium (wallflower) provides an excellent model for understanding these interactions due to its easily staged flowers and close taxonomic relationship to Arabidopsis. This has facilitated microarray analysis of gene expression during petal senescence and provided gene markers for following the effects of treatments on different regulatory pathways. Results In detached Erysimum linifolium (wallflower) flowers ethylene production peaks in open flowers. Furthermore senescence is delayed by treatments with the ethylene signalling inhibitor silver thiosulphate, and accelerated with ethylene released by 2-chloroethylphosphonic acid. Both treatments with exogenous cytokinin, or 6-methyl purine (which is an inhibitor of cytokinin oxidase), delay petal senescence. However, treatment with cytokinin also increases ethylene biosynthesis. Despite the similar effects on senescence, transcript abundance of gene markers is affected differentially by the treatments. A significant rise in transcript abundance of WLS73 (a putative aminocyclopropanecarboxylate oxidase) was abolished by cytokinin or 6-methyl purine treatments. In contrast, WFSAG12 transcript (a senescence marker) continued to accumulate significantly, albeit at a reduced rate. Silver thiosulphate suppressed the increase in transcript abundance both of WFSAG12 and WLS73. Activity of reactive oxygen species scavenging enzymes changed during senescence. Treatments that increased cytokinin levels, or inhibited ethylene action, reduced accumulation of hydrogen peroxide. Furthermore, although auxin levels rose with senescence, treatments that delayed early senescence did not affect transcript abundance of WPS46, an auxin-induced gene. Conclusions A model for the interaction between cytokinins, ethylene, reactive oxygen species and auxin in the regulation of floral senescence in wallflowers is proposed. The combined increase in ethylene and reduction in cytokinin triggers the initiation of senescence and these two plant growth regulators directly or indirectly result in increased reactive oxygen species levels. A fall in conjugated auxin and/or the total auxin pool eventually triggers abscission

Surgical Approach to Hidradenitis Suppurativa

Hidradenitis suppurativa is a chronic inflammatory skin condition characterized by painful nodules, abscesses, and sinus tracts that may lead to irreversible scarring complications. Therapeutic options include antibiotics, biologic therapies, and surgical procedures. Current management of hidradenitis suppurativa favors early surgical intervention along with medical therapy to promote healing and minimize scars and complications in a disease characterized by a therapeutic window of opportunity. Surgical techniques range from incision and drainage to wide excision, with varying recurrence rates mainly based on the extent of procedures. Reconstruction techniques would vary primarily based on the extent of the defect and the area involved. In all cases, a good preoperative planning and delimitation with imaging modalities, preferably intra- or perioperative facilitates complete removal of involved tissue, preserving the integrity and function of healthy skin and minimizing recurrences. Resumen: La hidradenitis supurativa es una enfermedad inflamatoria crónica de la piel caracterizada por nódulos dolorosos, abscesos y tractos fistulosos que pueden dar lugar a complicaciones cicatriciales irreversibles. Dentro de las opciones terapéuticas se incluyen el tratamiento con antibióticos, las terapias biológicas y los procedimientos quirúrgicos. El tratamiento actual de la hidradenitis supurativa promueve una intervención quirúrgica temprana junto con el uso de la terapia médica, con lo que se busca favorecer la curación y minimizar las cicatrices y complicaciones en una enfermedad que se caracteriza por una ventana de oportunidad terapéutica. Las técnicas quirúrgicas van desde la incisión y el drenaje hasta la escisión amplia, con tasas de recurrencia variables basadas principalmente en la extensión de los procedimientos. Las técnicas de reconstrucción varían principalmente en función de la extensión del defecto y de la zona afectada. En todos los casos, una buena planificación y delimitación preoperatoria con pruebas de imagen, preferiblemente intra o perioperatoria facilita la extirpación completa del tejido implicado, preservando la integridad y función de la piel sana y minimizando las recidivas

[Artículo traducido] Tratamiento quirúrgico de la hidradenitis supurativa

Resumen: La hidradenitis supurativa es una enfermedad inflamatoria crónica de la piel caracterizada por nódulos dolorosos, abscesos y tractos fistulosos que pueden dar lugar a complicaciones cicatriciales irreversibles. Dentro de las opciones terapéuticas se incluyen el tratamiento con antibióticos, las terapias biológicas y los procedimientos quirúrgicos. El tratamiento actual de la hidradenitis supurativa promueve una intervención quirúrgica temprana junto con el uso de la terapia médica, con lo que se busca favorecer la curación y minimizar las cicatrices y complicaciones en una enfermedad que se caracteriza por una ventana de oportunidad terapéutica. Las técnicas quirúrgicas van desde la incisión y el drenaje hasta la escisión amplia, con tasas de recurrencia variables en base a principalmente la extensión de los procedimientos. Las técnicas de reconstrucción varían principalmente en función de la extensión del defecto y de la zona afectada. En todos los casos, una buena planificación y delimitación preoperatoria con pruebas de imagen, preferiblemente intra o perioperatoria facilita la extirpación completa del tejido implicado, preservando la integridad y función de la piel sana y minimizando las recidivas. Abstract: Hidradenitis suppurativa is a chronic inflammatory skin condition characterized by painful nodules, abscesses, and sinus tracts that may lead to irreversible scarring complications. Therapeutic options include antibiotics, biologic therapies, and surgical procedures. Current management of hidradenitis suppurativa favors early surgical intervention along with medical therapy to promote healing and minimize scars and complications in a disease characterized by a therapeutic window of opportunity. Surgical techniques range from incision and drainage to wide excision, with varying recurrence rates mainly based on the extent of procedures. Reconstruction techniques would vary primarily based on the extent of the defect and the area involved. In all cases, a good preoperative planning and delimitation with imaging modalities, preferably intra- or perioperative facilitates complete removal of involved tissue, preserving the integrity and function of healthy skin and minimizing recurrences