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Hyaluronic acid (Hy) is a natural linear polymer that is widely distributed in different organisms, especially in the articular cartilage and the synovial fluid. During tissue injury due to oxidative stress, Hy plays an important protective role. All the beneficial properties of Hy make the polymer attractive for many biomedical uses; however, the low stability and short biological half-life limit Hy application. To overcome these problems, the addition of small antioxidant molecules to Hy solution has been employed to protect the molecular integrity of Hy or delay its degradation. Carnosine (β-alanyl-L-histidine, Car) protects cells from the damage due to the reactive species derived from oxygen (ROS), nitrogen (RNS) or carbonyl groups (RCS). Car inhibits the degradation of hyaluronan induced by free radical processes in vitro but, like Hy, the potential protective action of Car is drastically hampered by the enzymatic hydrolysis in vivo. Recently, we conjugated Hy to Car and the derivatives (HyCar) showed protective effects in experimental models of osteoarthritis and rheumatoid arthritis in vivo. Here we report the antioxidant activity exerted by HyCar against ROS, RNS and RCS. Moreover, we tested if the covalent conjugation between Hy and Car inhibits the enzymatic hydrolysis of the polymer and the dipeptide backbone. We found that the antioxidant properties and the resistance to the enzymatic hydrolysis of Hy and Car are greatly improved by the conjugation.

Several studies demonstrated the pharmacological actions of carnosine as well as hyaluronic acid (HA) during joint inflammation. In that regard, the aim of this study was to investigate the protective effect of a new HA -Carnosine conjugate (FidHycarn) on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis (CIA). CIA was induced by two intradermal injections of 100 μl of an emulsion of collagen (CII) and complete Freund's adjuvant (CFA) at the base of the tail on day 0 and 21. At 35 day post CIA induction, the animals were sacrificed.CII injection caused erythema and edema in the hind paws, histological alterations with erosion of the joint cartilage as well as behavioral changes. Oral treatment with FidHycarn starting at the onset of arthritis (day 25) ameliorated the clinical signs, improved behavioral deficits as well as decreased histological and radiographic alterations. The degree of oxidative damage evaluated by inducible nitric oxide synthase (iNOS), nitrotyrosine, poly-ADP-ribose (PAR) expressions and malondialdehyde (MDA) levels, was also significantly reduced in Carnosine+HA association and FidHycarn treated mice. Moreover, the levels of proinflammatory cytokines and chemokines and cyclo-oxygenase COX-2 enzyme were also more significantly reduced by Carnosine+HA and FidHycarn compared to carnosine alone. However, interestingly, in some cases, the effects of FidHycarn were more important than Carnosine+HA association and not statistically different to methotrexate (MTX) used as positive control.Thus, the conjugation of Carnosine with HA (FidHycarn) could represent an interesting therapeutic strategy to combat arthritis disorders.

Osteoarthritis (OA) is a disease that currently has no cure. There are numerous studies showing that carnosine and hyaluronic acid (HA) have a positive pharmacological action during joint inflammation. For this reason, the goal of this research was to discover the protective effect of a new carnosine conjugate with hyaluronic acid (FidHycarn) on the inflammatory response and on the cartilage degradation in an in vivo experimental model of OA. This model was induced by a single intra-articular (i.ar.) injection of 25 µL of normal saline with 1 mg of monosodium iodoacetate solution (MIA) in the knee joint of rats. MIA injection caused histological alterations and degradation of the cartilage, as well as behavioral changes. Oral treatment with FidHycarn ameliorated the macroscopic signs, improved thermal hyperalgesia and the weight distribution of the hind paw, and decreased histological and radiographic alterations. The oxidative damage was analyzed by evaluating the levels of nitrotyrosine and inducible nitric oxide synthase (iNOS) that were significantly reduced in FidHycarn rats. Moreover, the levels of pro-inflammatory cytokines and chemokines were also significantly reduced by FidHycarn. Therefore, for the first time, the effectiveness of oral administration of FidHycarn has been demonstrated in an osteoarthritis model. In conclusion, the new FidHycarn could represent an interesting therapeutic strategy to combat osteoarthritis.

Este ensaio teórico procura associar o conhecimento sobre processos de internacionalização que consideram aspectos econômicos como motivadores e aspectos culturais como barreiras a serem enfrentadas, aos aspectos inerentes à Teoria Institucional. Conceitos inerentes à Teoria Institucional são considerados como residuais por alguns autores ao tratarem de variáveis no nível de país dentro do processo de internacionalização, os quais nem sempre aprofundam o estudo sobre a influência das instituições na internacionalização de uma empresa. Revisou-se a literatura versando sobre processos de internacionalização de empresas, teoria institucional e uma abordagem que assume uma visão baseada em instituições como complementar às visões baseadas na indústria e em recursos como estratégia de internacionalização, constituindo estas três visões o tripé da estratégia, considerando também a influência do ambiente institucional na escolha de uma companhia multinacional pelo modo de entrada em um novo país. Conclui-se que a presença do aspecto institucional está, no mínimo, implícita ao se tratar de questões culturais em processos de internacionalização, e que não pode ser desconsiderada objetivando o sucesso de tais estratégias. [ABSTRACT FROM AUTHOR]