Complejo anómalo vascular exudativo perifoveal (PEVAC) / Perifoveal exudative vascular anomalous complex (PEVAC)

Se presentan 3 casos de pacientes, con 66, 80 y 23años de edad, que presentaron una pérdida de visión unilateral. La tomografía de coherencia óptica (OCT) mostró edema macular junto con una lesión redondeada de pared hiperreflectiva y la angiografía con fluoresceína (AFG) de dos de ellos, dilataciones aneurismáticas perifoveales hiperfluorescentes con exudación. Ninguno de los casos mostró respuesta al tratamiento tras un año de seguimiento, diagnosticándose finalmente de complejo anómalo vascular exudativo perifoveal (PEVAC) (AU)

We present three cases of patients aged 66, 80 and 23, who presented unilateral vision loss. Optical coherence tomography (OCT) in all of them showed macular oedema and a rounded lesion with hyper-reflective wall, and fluorescein angiography (FAG) in two of them showed hyperfluorescent perifoveal aneurysmal dilations with exudation. None of the cases showed response to treatment after one year of follow-up, finally being diagnosed with perifoveal exudative vascular anomalous complex (PEVAC) (AU)

Perifoveal exudative vascular anomalous complex (PEVAC).

We present three cases of patients aged 66, 80 and 23, who presented unilateral vision loss. Optical coherence tomography (OCT) in all of them showed macular oedema and a rounded lesion with hyperreflective wall, and fluorescein angiography (FAG) in two of them showed hyperfluorescent perifoveal aneurysmal dilations with exudation. None of the cases showed response to treatment after one year of follow-up, finally being diagnosed with Perifoveal Exudative Vascular Anomalous Complex (PEVAC).

FAIR data sharing: The roles of common data elements and harmonization.

The value of robust and responsible data sharing in clinical research and healthcare is recognized by patients, patient advocacy groups, researchers, journal editors, and the healthcare industry globally. Privacy and security concerns acknowledged, the act of exchanging data (interoperability) along with its meaning (semantic interoperability) across studies and between partners has been difficult, if not elusive. For shared data to retain its value, a recommendation has been made to follow the Findable, Accessible, Interoperable, Reusable (FAIR) principles. Without applying appropriate data exchange standards with domain-relevant content standards and accessible rich metadata that uses applicable terminologies, interoperability is burdened by the need for transformation and/or mapping. These obstacles to interoperability limit the findability, accessibility and reusability of data, thus diminishing its value and making it impossible to adhere to FAIR principles. One effort to standardize data collection has been through common data elements (CDEs). CDEs are data collection units comprising one or more questions together with a set of valid values. Some CDEs contain standardized terminology concepts that define the meaning of the data, and others include links to unique terminology concept identifiers and unique identifiers for each CDE; however, usually CDEs are defined for specific projects or collaborations and lack traceable or machine readable semantics. While the name implies that these are 'common', this has not necessarily been a requirement, and many CDEs have not been commonly used. The National Institutes of Health (NIH) CDEs are, in fact, a conglomerate of CDEs developed in silos by various NIH institutes. Therefore, CDEs have not brought the anticipated benefit to the industry through widescale interoperability, nor is there widespread reuse of CDEs. Certain institutes in the NIH recommend, albeit do not enforce, institute-specific preferred CDEs; however, at the NIH level a preponderance of choice and a lack of any overarching harmonization of CDEs or consistency in linking them to controlled terminology or common identifiers create confusion for researchers in their efforts to identify the best CDEs for their protocol. The problem of comparing data among studies is exacerbated when researchers select different CDEs for the same variable or data collection field. This manuscript explores reasons for the disappointingly low adoption of CDEs and the inability of CDEs or other clinical research standards to broadly solve the interoperability and data sharing problems. Recommendations are offered for rectifying this situation to enable responsible data sharing that will help in adherence to FAIR principles and the realization of Learning Health Systems for the sake of all of us as patients.

Establishing a regional network of academic centers to support decision making for new vaccine introduction in Latin America and the Caribbean: the ProVac experience.

BACKGROUND: The Pan American Health Organization's ProVac Initiative, designed to strengthen national decision making regarding the introduction of new vaccines, was initiated in 2004. Central to realizing ProVac's vision of regional capacity building, the ProVac Network of Centers of Excellence (CoEs) was established in 2010 to provide research support to the ProVac Initiative, leveraging existing capacity at Latin American and Caribbean (LAC) universities. We describe the process of establishing the ProVac Network of CoEs and its initial outcomes and challenges. METHODS: A survey was sent to academic, not-for-profit institutions in LAC that had recently published work in the areas of clinical decision sciences and health economic analysis. Centers invited to join the Network were selected by an international committee on the basis of the survey results. Selection criteria included academic productivity in immunization-related work, team size and expertise, successful collaboration with governmental agencies and international organizations, and experience in training and education. The Network currently includes five academic institutions across LAC. RESULTS: Through open dialog and negotiation, specific projects were assigned to centers according to their areas of expertise. Collaboration among centers was highly encouraged. Faculty from ProVac's technical partners were assigned as focal points for each project. The resulting work led to the development and piloting of tools, methodological guides, and training materials that support countries in assessing existing evidence and generating new evidence on vaccine introduction. The evidence generated is shared with country-level decision makers and the scientific community. CONCLUSIONS: As the ProVac Initiative expands to other regions of the world with support from immunization and public health partners, the establishment of other regional and global networks of CoEs will be critical. The experience of LAC in creating the current network could benefit the formation of similar structures that support evidence-based decisions regarding new public health interventions.

Diet selection and live-weight changes of two breeds of goats grazing on heathlands.

Diet selection, live-weight changes and productivity per hectare of two breeds of goats (Cashmere and local Celtiberic) managed in natural vegetation dominated by heather, and the effect of stocking rate (high or low) in the Cashmere breed, were studied during four grazing seasons. Breed had a significant (P < 0.01) effect on the available biomass and its components over the experimental period as a consequence of the differences in dietary components selected by the animals. Local goats produced a greater reduction in short and tall heather and in the percentage of leaves in the tall heather. Live-weight changes were significantly (P < 0.001) different between breeds. Over all experimental years Cashmere goats maintained weight under both low and high stocking rate (4 and - 1 g/day respectively), while local Celtiberic goats lost 30 g/day.Across all grazing seasons and experimental years stocking rate did not significantly affect individual live-weight changes of Cashmere goats. Productivity per hectare did not differ significantly (P>0.05) between high ( - 0.6 kg/ha) and low stocking rate treatments (4.1 kg/ha). However it was significantly (P < 0.001) worse for the local breed treatment ( - 51 kg/ha).As a consequence, in these vegetation communities with low abundance and poor quality of herbaceous plants it will be impossible to develop sustainable systems from the animal production point of view, and their management would need to be integrated during the grazing season by alternating with vegetation communities with better quality.

Rheology of hydroxyethylated starch aqueous systems. Analysis of gel formation.

This paper reports dynamic viscoelastic and steady shear measurements of aqueous solutions of two commercial hydroxyethyl ethers of potato starch, allowing us to define three different viscoelastic regions, depending on the polymer concentrations. The fluid-like zone (I) corresponds to a homogeneous solution, free of associations between chains, where the linear viscoelastic model can be applied; the fluid-gel transition zone (II) is associated with the rheology of complex systems which possess intermolecular specific interactions; and the gel-like zone (III) involves a network formation giving rise to a gel. The reversibility of the hydrogels was studied by means of steady/dynamic transient experiments allowing breakdown of the gel network and analysis of rehealing. Comparing the elastic moduli of the starch derivative gels leads us to assume that the functionality depends on the capacity to form hydrogen-bonding associations between polymer chains.