Ultrastructure and Glycoconjugate Pattern ofthe Foot Epithelium of the Abalone Haliotis tuberculata (Linnaeus, 1758) (Gastropoda, Haliotidae)

The foot epithelium of the gastropod Haliotis tuberculata is studied by light and electron microscopy in order to contribute to the understanding of the anatomy and functional morphology of the mollusks integument. Study of the external surface by scanning electron microscopy reveals that the side foot epithelium is characterized by a microvillus border with a very scant presence of small ciliary tufts, but the sole foot epithelium bears a dense field of long cilia. Ultrastructural examination by transmission electron microscopy of the side epithelial cells shows deeply pigmented cells with high electron-dense granular content which are not observed in the epithelial sole cells. Along the pedal epithelium, seven types of secretory cells are present; furthermore, two types of subepithelial glands are located just in the sole foot. The presence and composition of glycoconjugates in the secretory cells and subepithelial glands are analyzed by conventional and lectin histochemistry. Subepithelial glands contain mainly N-glycoproteins rich in fucose and mannose whereas secretory cells present mostly acidic sulphated glycoconjugates such as glycosaminoglycans and mucins, which are rich in galactose, N-acetyl-galactosamine, and N-acetyl-glucosamine. No sialic acid is present in the foot epithelium.Versión del edito

Ingression Progression Complexes Control Extracellular Matrix Remodelling during Cytokinesis in Budding Yeast

Eukaryotic cells must coordinate contraction of the actomyosin ring at the division site together with ingression of the plasma membrane and remodelling of the extracellular matrix (ECM) to support cytokinesis, but the underlying mechanisms are still poorly understood. In eukaryotes, glycosyltransferases that synthesise ECM polysaccharides are emerging as key factors during cytokinesis. The budding yeast chitin synthase Chs2 makes the primary septum, a special layer of the ECM, which is an essential process during cell division. Here we isolated a group of actomyosin ring components that form complexes together with Chs2 at the cleavage site at the end of the cell cycle, which we named ‘ingression progression complexes’ (IPCs). In addition to type II myosin, the IQGAP protein Iqg1 and Chs2, IPCs contain the F-BAR protein Hof1, and the cytokinesis regulators Inn1 and Cyk3. We describe the molecular mechanism by which chitin synthase is activated by direct association of the C2 domain of Inn1, and the transglutaminase-like domain of Cyk3, with the catalytic domain of Chs2. We used an experimental system to find a previously unanticipated role for the C-terminus of Inn1 in preventing the untimely activation of Chs2 at the cleavage site until Cyk3 releases the block on Chs2 activity during late mitosis. These findings support a model for the co-ordinated regulation of cell division in budding yeast, in which IPCs play a central role

An Online Training Intervention on Prehospital Stroke Codes in Catalonia to Improve the Knowledge, Pre-Notification Compliance and Time Performance of Emergency Medical Services Professionals

Strokes are a time-dependent medical emergency. The training of emergency medical service (EMS) professionals is essential to ensure the activation of stroke codes with pre-notification, as well as a rapid transfer to achieve early therapy. New assessment scales for the detection of patients with suspected large vessel occlusion ensures earlier access to endovascular therapy. The aim of this study was to evaluate the impact on an online training intervention focused on the Rapid Arterial oCclusion Evaluation (RACE) scoring of EMS professionals based on the prehospital stroke code in Catalonia from 2014 to 2018 in a pre-post intervention study. All Catalonian EMS professionals and the clinical records from primary stroke patients were included. The Kirkpatrick model guided the evaluation of the intervention. Data were collected on the knowledge on stroke recognition and management, pre-notification compliance, activated stroke codes and time performance of EMS professionals. Knowledge improved significatively in most items and across all categories, reaching a global achievement of 82%. Pre-notification compliance also improved significantly and remained high in the long-term. Increasingly higher notification of RACE scores were recorded from 60% at baseline to 96.3% in 2018, and increased on-site clinical care time and global time were also observed. Therefore, the online training intervention was effective for increasing EMS professionals' knowledge and pre-notification compliance upon stroke code activation, and the wide adoption of a new prehospital scale for the assessment of stroke severity (i.e., the RACE scale) was achieved

Mecanismo y regulación de la citoquinesis en la levadura Saccharomyces cerevisiae

ABSTRACT: In budding yeast Saccharomyces cerevisiae, contraction of the actomyosin ring is coupled to the synthesis of a chitinous septum by Chs2 protein. To understand how this enzyme works, we tried a structural approach, which did not succeed as we did not have enough protein to work with. Hence, we switched to a genetic approach, in which we studied the influence of Cyk3 protein in chitin synthesis from Chs2 and the contraction of the actomyosin ring. Cyk3 interacts physically with Chs2 through fragments containing a transglutaminase-like domain. This domain is also crucial for the induction of Chs2 chitin synthase activity from Cyk3. Finally, a coordination model was proposed between the contraction of the actomyosin ring with the synthesis of a chitin septum between mother and daughter cells during cytokinesis in budding yeast Saccharomyces cerevisiae.RESUMEN: En la levadura Saccharomyces cerevisiae, la contracción del anillo de actinomiosina va acompañada de la síntesis de un septo de quitina por parte de la proteína Chs2. Para entender este enzima, se probó un estudio con un enfoque estructural, en el que no se obtuvo suficiente proteína. Así, se cambió el estudio a un enfoque genético, en el cual se estudió la influencia de la proteína Cyk3 en la síntesis de quitina por parte de Chs2 y la contracción del anillo de actinomiosina. Cyk3 interacciona físicamente con Chs2 a través de fragmentos que contienen un dominio similar a transglutaminasa. Dicho dominio es además crucial para la inducción de la actividad quitín sintasa en Chs2 por parte de Cyk3. Finalmente, se propuso un modelo de coordinación de la contracción del anillo de actinomiosina con la síntesis del septo de quitina en citoquinesis en la levadura Saccharomyces cerevisiae.Esta Tesis ha sido realizada en el Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC) y la Facultad de Medicina de la Universidad de Cantabria en Santander, Cantabria. La financiación necesaria para la realización de esta Tesis ha sido aportada por el Ministerio de Economía y Competitividad, gracias a la ayuda predoctoral de formación de personal investigador (FPI) BES-2012-058697, asociada al proyecto BFU2011-23193