10 research outputs found

    Targeting Toll-like Receptors in Autoimmunity

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    In the past few years there has been an increasing appreciation of the importance of Toll-like receptors (TLRs), not just in immunity, but also in autoimmune diseases. TLRs were first identified as sensors of viral and bacterial pathogens that form an integral part of the innate immune response. It was later discovered that these receptors can also respond to endogenous ligands that are produced as a result of tissue damage. This lead to the hypothesis that TLRs may be key contributors to the pathogenesis of chronic inflammatory conditions. A large body of data supporting the role of TLRs in autoimmunity has emerged from animal models and more data is increasingly being generated from human studies as further tools to examine these receptors have become available. Developing strategies to manipulate TLR function is of great interest in autoimmunity, as well as other diseases that include allergy and cancer. This review explores the evidence that points to a role for TLRs in autoimmunity and highlights some of the potential ways in which modulation of their action may yield clinical benefits

    Size-Dependent Consequences of Exogenous Cortisol Manipulation on Overwinter Survival and Condition of Largemouth Bass

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    Little is known about the size-dependent consequences of stressors on wild animals, which is particularly relevant during winter where size-specific trends in survival are common. Here, exogenous cortisol manipulation was used to investigate the effect of a physiological challenge on overwinter mortality and spring condition of largemouth bass (Micropterus salmoides) across a range of body sizes. Fish were wild-caught in the fall, assigned into either control or cortisol manipulated treatments, and held in replicated experimental ponds. For bass that survived the winter, length, mass, and health metrics (e.g., gonadosomatic index [GSI], hepatosomatic index [HSI], and water content) were determined in the spring. Winter survival was marginally lower for cortisol treated bass; however, there was no influence of initial length, mass, or condition on overwinter survival. When bass were grouped by size, survival was significantly higher for bass 300–350 mm in length compared to those <200 mm. The treatment did not strongly influence spring health metrics, suggesting that largemouth bass that survived the winter were able to recover from the effects of the cortisol elevation. Initial size and sex were linked to some spring health metrics, with large females having the highest GSI and HSI scores. Overall, results from this study do not support the notion that there are size-dependent responses to cortisol manipulation in a teleost fish. Rather, this type of physiological challenge may modulate the natural rates of winter mortality that are primarily driven by starvation and predation, independent of body size, in subadult and adult largemouth bass

    Efeito cicatrizante e atividade antibacteriana da Calendula officinalis L. cultivada no Brasil Healing effect and antibacterial activity of Calendula officinalis L. cultivated in Brazil

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    Desde a antiguidade propriedades medicinais são atribuídas às flores da Calendula officinalis L. (Asteraceae) destacando-se a atividade cicatrizante. Estudos sobre a atividade geral de plantas medicinais na cicatrização vêm sendo realizados, sem especificar sobre qual das fases da cicatrização a planta atua. Neste trabalho a atividade cicatrizante e antiinflamatória do extrato etanólico das flores da C. officinalis cultivada no Brasil foi avaliada em feridas cutâneas de ratos Wistar, por meio de avaliação macroscópica e histológica. A atividade antimicrobiana do extrato e das frações hexânica e diclorometano também foi avaliada. A atividade antiinflamatória do extrato etanólico da calêndula foi atribuída à diminuição da exsudação serosa, da hiperemia, da deposição de fibrina e da hiperplasia epidermal, além de resultar em crostas mais delgadas e umedecidas. Observaram-se também aumento de colágeno no tecido de granulação e efeito antibacteriano. Assim, o extrato etanólico da calêndula atuou de forma positiva sobre a atividade cicatricial em feridas cutâneas de ratos, bem como apresentou atividade antibacteriana in vitro.<br>Since ancient history medicinal properties are attributed to flowers of Calendula officinalis L. (Asteraceae), mainly concerning its healing activity. Studies about the general activity of medicinal plants in healing wounds have been conducted without specifying in which healing phase the plant acts. In this work, the anti-inflammatory and healing activity of the ethanolic extract of C. officinalis flowers cultured in Brazil was evaluated in cutaneous wounds of Wistar rats through macroscopic and histological evaluation. The antibacterial activity of the extract and dichloromethane and hexane fractions was also evaluated. The anti-inflammatory activity of calendula ethanolic extract led to a reduction in plasmatic exudation, hyperemia, fibrin deposition and epidermal hyperplasia, besides resulting in less edematous crusts. There was also an increase in collagen in the granulation tissue and an antibacterial effect. Therefore, calendula ethanolic extract positively acted on the healing process of cutaneous wounds of rats and presented in vitro antibacterial activity

    Nanomedicines to Treat Skin Pathologies with Natural Molecules

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    Global COVID-19 lockdown highlights humans as both threats and custodians of the environment

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    The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness
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