Browsing by Author "Carvalho, Maria M."
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- Amentadione from the alga Cystoseira usneoides as a novel osteoarthritis trotective agent in an ex vivo co-culture OA ModelPublication . Araujo, Nuna C. P.; Viegas, Carla; Zubía, Eva; Magalhães, Joana; Ramos, Acácio; Carvalho, Maria M.; Cruz, Henrique; Sousa, João Paulo; Blanco, Francisco J.; Vermeer, Cees; Simes, DinaOsteoarthritis (OA) remains a prevalent chronic disease without effective prevention and treatment. Amentadione (YP), a meroditerpenoid purified from the alga Cystoseira usneoides, has demonstrated anti-inflammatory activity. Here, we investigated the YP anti-osteoarthritic potential, by using a novel OA preclinical drug development pipeline designed to evaluate the anti-inflammatory and anti-mineralizing activities of potential OA-protective compounds. The workflow was based on in vitro primary cell cultures followed by human cartilage explants assays and a new OA co-culture model, combining cartilage explants with synoviocytes under interleukin-1β (IL-1β) or hydroxyapatite (HAP) stimulation. A combination of gene expression analysis and measurement of inflammatory mediators showed that the proposed model mimicked early disease stages, while YP counteracted inflammatory responses by downregulation of COX-2 and IL-6, improved cartilage homeostasis by downregulation of MMP3 and the chondrocytes hypertrophic differentiation factors Col10 and Runx2. Importantly, YP downregulated NF-κB gene expression and decreased phosphorylated IkBα/total IkBα ratio in chondrocytes. These results indicate the co-culture as a relevant pre-clinical OA model, and strongly suggest YP as a cartilage protective factor by inhibiting inflammatory, mineralizing, catabolic and differentiation processes during OA development, through inhibition of NF-κB signaling pathways, with high therapeutic potential.
- Impact of age, gender and body mass index on the efficacy of tranexamic acid in total knee arthroplastyPublication . Viegas, Rui; Kumar, Abhishek; Carvalho, Maria M.; Vide, João; Fontes, Ana Paula; Sousa, João P.Background: Tranexamic acid (TXA) is effective and safe in decreasing blood loss and transfusion rate in total knee arthroplasty (TKA). Few studies focused on the role of patients’ characteristics on the efficacy of TXA in TKA. The purpose of this study was to conduct a retrospective analysis to investigate if age, gender and BMI influence the efficacy of TXA in reducing perioperative blood loss in TKA. Methods: We did an observational study including 366 consecutive patients undergoing TKA in Hospital Particular do Algarve between January 2011 and April 2019 which were divided in two groups: intraoperative administration of intravenous TXA (TXA Group) and no administration of TXA (Control Group). The perioperative blood loss between groups and their relation with age, gender and BMI was compared. Results: Of the 366 patients, 225 (61%) received TXA. In both groups, age did not correlate to the blood loss. Women in the TXA group had less perioperative blood loss than in the control group. No such difference was found for men. The normal weight group showed no difference in perioperative blood loss with or without TXA administration. However, there was a statistically significant difference in the overweight and obese groups. The mean perioperative blood loss was higher in the control group (854±342 ml) than in the TXA group (720±335 ml). Conclusions: TXA administration is efficient in controlling TKA associated hemorrhage in overweight and obese individuals and in women but it doesn’t have that effect in normal weight patients or in men.