Spatial metabolomics and its application in the liver.

Hepatocytes work in highly structured, repetitive hepatic lobules. Blood flow across the radial axis of the lobule generates oxygen, nutrient, and hormone gradients, which result in zoned spatial variability and functional diversity. This large heterogeneity suggests that hepatocytes in different lobule zones may have distinct gene expression profiles, metabolic features, regenerative capacity, and susceptibility to damage. Here, we describe the principles of liver zonation, introduce metabolomic approaches to study the spatial heterogeneity of the liver, and highlight the possibility of exploring the spatial metabolic profile, leading to a deeper understanding of the tissue metabolic organization. Spatial metabolomics can also reveal intercellular heterogeneity and its contribution to liver disease. These approaches facilitate the global characterization of liver metabolic function with high spatial resolution along physiological and pathological time scales. This review summarizes the state of the art for spatially resolved metabolomic analysis and the challenges that hinder the achievement of metabolome coverage at the single-cell level. We also discuss several major contributions to the understanding of liver spatial metabolism and conclude with our opinion on the future developments and applications of these exciting new technologies.

Cytochrome c6 is the main respiratory and photosynthetic soluble electron donor in heterocysts of the cyanobacterium Anabaena sp. PCC 7120.

Cytochrome c6 is a soluble electron carrier, present in all known cyanobacteria, that has been replaced by plastocyanin in plants. Despite their high structural differences, both proteins have been reported to be isofunctional in cyanobacteria and green algae, acting as alternative electron carriers from the cytochrome b6-f complex to photosystem I or terminal oxidases. We have investigated the subcellular localization of both cytochrome c6 and plastocyanin in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 grown in the presence of combined nitrogen and under diazotrophic conditions. Our studies conclude that cytochrome c6 is expressed at significant levels in heterocysts, even in the presence of copper, condition in which it is strongly repressed in vegetative cells. However, the copper-dependent regulation of plastocyanin is not altered in heterocysts. In addition, in heterocysts, cytochrome c6 has shown to be the main soluble electron carrier to cytochrome c oxidase-2 in respiration. A cytochrome c6 deletion mutant is unable to grow under diazotrophic conditions in the presence of copper, suggesting that cytochrome c6 plays an essential role in the physiology of heterocysts that cannot be covered by plastocyanin.

Optimisation of a potency assay for the assessment of immunomodulative potential of clinical grade multipotent mesenchymal stromal cells.

Clinical use of multipotent Mesenchymal Stromal Cell (MSC)-based medicinal products requires their production in compliance with Good Manufacturing Practices, thus ensuring that the final drug product meets specifications consistently from batch to batch in terms of cell viability, identity, purity and potency. Potency relates to the efficacy of the medicine in its target clinical indication, so adequate release tests need to be defined and validated as quality controls. Herein we report the design and optimisation of parameters affecting the performance of an in vitro cell-based assay for assessing immunomodulatory potential of clinical grade MSC for human use, based on their capacity to inhibit proliferation of T lymphocytes under strong polyclonal stimuli. The resulting method was demonstrated to be reproducible and relatively simple to execute. Two case studies using clinical grade MSC are presented as examples to illustrate the applicability of the methodology described in this work.

Características de los casos de gangrena de Fournier atendidos en el Hospital Luis Vernaza de Guayaquil-Ecuador / Characteristics of Fournier gangrene cases treated at the Luis Vernaza Hospital in Guayaquil-Ecuador

La gangrena de Fournier es una fascitis necrotizante causada por una infección polimicrobiana originada en el área genitourinaria o anorectal. Esta patología se asocia con una alta mortalidad hospitalaria. Objetivo Analizar las características de los casos de gangrena de Fournier atendidos en el hospital Luis Vernaza de la Junta de Benefcencia de Guayaquil, Ecuador. Diseño Serie de casos. Lugar y sujetos Un total de 26 casos con gangrena de Fournier, tratados en el hospital Luis Vernaza de Guayaquil, durante el período 2005 ­ 2016. Mediciones principales Cuadro clínico, comorbilidades, resultados de cultivos bacterianos iniciales y subsecuentes; empleo de derivaciones urinarias o digestivas, complicaciones intrahospitalarias, procedimientos quirúrgicos de reconstrucción y mortalidad total. Resultados El 38.5% de los pacientes tuvieron entre 60 y 74 años de edad. La estancia hospitalaria tuvo un promedio de 75.3 días. Las comorbilidades más frecuentes fueron diabetes mellitus tipo 2 (61.5%), hipertensión arterial (38.4%) y enfermedades venéreas (19.2%). Los síntomas más comunes fueron dolor escrotal (92.3%) y presencia de masa escrotal (80.7%). El número de limpiezas quirúrgicas tuvo una media de 3 procedimientos por paciente. Los cultivos iniciales fueron en un 57.2% polimicrobianos y la bacteria más identifcada fue Escherichia coli (46.7%). Luego de las limpiezas quirúrgicas y cuidados críticos, fue más frecuente la presencia de Klesbiella pneumoniae (55.6%). La derivación del tracto urinario se realizó en la mayoría de los casos con cistostomía mínima (61.6%). En una tercera parte de los pacientes hubo complicaciones quirúrgicas y/o médicas. Los pacientes se manejaron con cierres por segunda intención (69.23%), escrotoplastias (52%), injerto libre (66.7%), injerto en Y (33.3%), y colgajo por avance (48%). La mortalidad total fue del 20% (n=5). Conclusiones Las limpiezas quirúrgicas seriadas contribuyen a la mejoría, pero conllevan heridas cruentas que requieren reconstrucciones complejas. La estancia hospitalaria prolongada aumenta la probabilidad de infecciones nosocomiales asociadas a los cuidados de la salud