Delay of neuropathic pain sensitization after application of dexamethasone-loaded implant in sciatic nerve-injured rats

Neuroimmune interactions underlying the development of pain sensitization in models of neuropathic pain have been widely studied. In this study, we evaluated the development of allodynia and its reduction associated with peripheral antineuroinflammatory effects induced by a dexamethasone-loaded biodegradable implant. Chronic constriction injury (CCI) of the sciatic nerve was performed in Wistar rats. The electronic von Frey test was applied to assess mechanical allodynia. The dexamethasone-loaded implant was placed perineurally at the moment of CCI or 12 days after surgery. Dorsal root ganglia (DRG; L4-L5) were harvested and nuclear extracts were assayed by Western blot for detection of nuclear factor (NF)-κB p65/RelA translocation. Dexamethasone delivered from the implant delayed the development of allodynia for approximately three weeks in CCI rats when the implantation was performed at day 0, but allodynia was not reversed when the implantation was performed at day 12. NF-κB was activated in CCI rat DRG compared with naïve or sham animals (day 15), and dexamethasone implant inhibited p65/ RelA translocation in CCI rats compared with control. This study demonstrated that the dexamethasoneloaded implant suppresses allodynia development and peripheral neuroinflammation. This device can reduce the potential side effects associated with oral anti-inflammatory drugs

COVID-Inconfidentes - SARS-CoV-2 seroprevalence in two Brazilian urban areas during the pandemic first wave: study protocol and initial results

Background: A population study is an important tool that can be used to understand the actual epidemiological scenario of the Covid-19 in different territories, identify its magnitude, understand its transmission dynamics, and its demographic, geographical, and social distribution. Objective: The aim of this study was to determine the prevalence and dynamics of SARS-CoV-2 infection in the population of two Brazilian cities during the pandemic first wave and subsequent socioeconomic and health effects. Materials & methods: This paper described the methodological procedures adopted and the prevalence of the SARS-CoV-2 infection in the population. A household survey was conducted between October and December 2020, in two historic cities of Brazil's mining region. Anti-SARS-CoV-2 antibody was detected using the Wondfo® rapid test. The face-to-face interview consisted of administration of a questionnaire containing registration data, sociodemographic and economic variables, living habits, general health condition, mental health, sleep habits, and eating and nutrition. Results: We evaluated 1,762 residents, of which 764 (43.4%) were in Mariana and 998 (56.6%) in Ouro Preto. For both cities, 51.9% of the interviewees were female, with a predominance of the age range 35 to 59 years old (47.2%). The prevalence of the SARS-CoV-2 infection was 5.5% in all cities, 6.2% in Ouro Preto, and 4.7% in Mariana. The prevalence was similar between cities (P>0.05). Conclusion: The study was effective in verifying the seroprevalence of infection by the virus and its findings will enable further analyses of the health conditions of the population related to social isolation and the risk of infection with SARS-CoV-2

Generation of a triple-fluorescent mouse strain allows a dynamic and spatial visualization of different liver phagocytes in vivo

ABSTRACT Resident and circulating immune cells have been extensively studied due to their almost ubiquitous role in cell biology. Despite their classification under the “immune cell department”, it is becoming increasingly clear that these cells are involved in many different non-immune related phenomena, including fetus development, vascular formation, memory, social behavior and many other phenotypes. There is a huge potential in combining high-throughput assays - including flow cytometry and gene analysis - with in vivo imaging. This can improve our knowledge in both basic and clinical cell biology, and accessing the expression of markers that are relevant in the context of both homeostasis and disease conditions might be instrumental. Here we describe how we generated a novel mouse strain that spontaneously express three different fluorescence markers under control of well-studied receptors (CX3CR1, CCR2 and CD11c) that are involved in a plethora of stages of cell ontogenesis, maturation, migration and behavior. Also, we assess the percentage of the expression and co-expression of each marker under homeostasis conditions, and how these cells behave when a local inflammation is induced in the liver applying a cutting-edge technology to image cells by confocal intravital microscopy

Liver Immune Cells Release Type 1 Interferon Due to DNA Sensing and Amplify Liver Injury from Acetaminophen Overdose

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