Abstract Background Fibroblast-like synoviocytes (FLS) play a prominent role in rheumatoid synovitis and degradation of the extracellular matrix through the production of inflammatory cytokines and metalloproteinases (MMPs). Since animal models are frequently used for elucidating the disease mechanism and therapeutic development, it is relevant to study the ultrastructural characteristics and functional responses in human and mouse FLS. The objective of the study was to analyze ultrastructural characteristics, Interleukin-6 (IL-6) and Metalloproteinase-3 (MMP-3) production and the activation of intracellular pathways in Fibroblast like synoviocytes (FLS) cultures obtained from patients with rheumatoid arthritis (RA) and from mice with collagen-induced arthritis (CIA). Methods FLSs were obtained from RA patients (RA-FLSs) (n = 8) and mice with CIA (CIA-FLSs) (n = 4). Morphology was assessed by transmission and scanning electron microscopy. IL-6 and MMP-3 production was measured by ELISA, and activation of intracellular signaling pathways (NF-κB and MAPK: p-ERK1/2, p-P38 and p-JNK) was measured by Western blotting in cultures of RA-FLSs and CIA-FLSs stimulated with tumor necrosis factor-alpha (TNF-α) and IL-1β. Results RA-FLS and CIA-FLS cultures exhibited rich cytoplasm, rough endoplasmic reticula and prominent and well- developed Golgi complexes. Transmission electron microscopy demonstrated the presence of lamellar bodies, which are cytoplasmic structures related to surfactant production, in FLSs from both sources. Increased levels of pinocytosis and numbers of pinocytotic vesicles were observed in RA-FLSs (p < 0.05). Basal production of MMP-3 and IL-6 was present in RA-FLSs and CIA-FLSs. Regarding the production of MMP-3 and IL-6 and the activation of signaling pathways, the present study demonstrated a lower response to IL-1β by CIA-FLSs than by RA-FLSs. Conclusion This study provides a comprehensive understanding of the biology of RA-FLS and CIA-FLS. The differences and similarities in ultrastructural morphology and important inflammatory cytokines shown, contribute to future in vitro studies using RA-FLS and CIA-FLS, in addition, they indicate that the adoption of CIA-FLS for studies should take careful and be well designed, since they do not completely resemble human diseases.

Abstract The EPAs approach has had a great impact on medical education since it emerged in 2005. Its dissemination has required translation into several languages, sometimes generating terminological and meaning confusion. This paper is the result of an expert consensus procedure regarding the translation of key terms for understanding the EPA approach in Spanish and Portuguese. It was carried out through a process of meaning analysis of each term in its idiomatic context and of the practice of health professionals training in Latin America. Participated on this consensus by twelve professionals, teachers and scholars involved in the implementation and training with EPAs in eight countries, who participated as coordinator, facilitators or participants in the International Course Ins and Outs of EPAs for Latin America.

Resumen El enfoque de EPAs ha tenido un gran impacto en la educación médica desde que surgió en 2005. Su difusión a través de diferentes regiones del mundo ha requerido traducción a varios idiomas, y en algunas ocasiones ha generado confusiones terminológicas y de significado. Este artículo es el resultado de un consenso respecto de la traducción de términos clave para la comprensión del enfoque en español y portugués. Se llevó a cabo a través de un proceso de análisis de significado de cada término en el contexto idiomático y de la realidad de la formación de profesionales de la salud en Latinoamérica. Estuvo a cargo de doce profesionales, docentes y académicos involucrados en la implementación y formación con EPAs en ocho países, que formaron parte como responsables, facilitadores o participantes del International Course Ins and Outs of EPAs 2021 para Latinoamérica.