A3 receptor agonist modulates IL-1ß hippocampus levels in a rat model of neuropathic pain

Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed to evaluate the effect of a single dose of adenosine A3 receptor IB-MECA on inflammatory and neurotrophic parameters in rats subjected to a neuropathic pain model. Methods: 64 adult male Wistar rats were used. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve and the treatment consisted of a 0.5 µmol/kg dose of IB-MECA, a selective A3 adenosine receptor agonist, dissolved in 3% DMSO; vehicle groups received DMSO 3% in saline solution, and morphine groups received 5 mg/kg. Cerebral cortex and hippocampus IL-1ß, BDNF, and NGF levels were determined by Enzyme-Linked Immunosorbent assay. Results: The main outcome was that a single dose of IB-MECA was able to modulate the IL-1ß hippocampal levels in neuropathic pain induced by CCI and the DMSO increased IL-1ß and NGF hippocampal levels in sham-operated rats. However, we did not observe this effect when the DMSO was used as vehicle for IB-MECA, indicating that IB-MECA was able to prevent the effect of DMSO. Conclusions: Considering that the IL-1ß role in neuropathic pain and the contributions of the hippocampus are well explored, our result corroborates the relationship between the A3 receptor and the process of chronic pain maintenance.

Transcranial direct current stimulation did not revert the increased central and peripheral NGF levels induced by neuropathic pain in rats / Tratamento com estimulação transcraniana por corrente contínua não reverteu o aumento de NGF induzido por modelo de dor neuropática em ratos

ABSTRACT BACKGROUND AND OBJECTIVES: The expression of nerve growth factor (NGF) in the large-size neurons may represent a key role in the neuronal synaptic plasticity and re-organization of neuronal function after a nerve injury. Transcranial direct current stimulation (tDCS) is a non-invasive method of cerebral stimulation and represents a promising tool to pain management since it promotes neuroplasticity in the central system, and it can be combined with other interventions. The aim was to investigate the effects of tDCS in the NGF levels in central and peripheral nervous system structures of rats submitted to a neuropathic pain (NP) model. METHODS: The chronic constriction injury (CCI) of sciatic nerve was used for the induction of NP. For sham surgery, the sciatic nerve was exposed, but without any ligation. The control group did not undergo surgical procedure. After the establishment of NP, treated groups were subjected to tDCS treatment 0.5 mA/20min/day/8 days. NGF levels in cerebral cortex, spinal cord and sciatic nerve were determined by sandwich-ELISA at 48 hours and 7 days after the end of treatment. RESULTS: The CCI model increased NGF levels in all three structures analyzed at long-lasting time, evidencing the importance of this neurotrophin in neuropathic pain condition. On the other hand, there was no tDCS effect in the central and peripheral NGF levels discarding the participation of this neurotrophin in the analgesic tDCS effect. CONCLUSION: tDCS modulation effects of nociceptive pathways seem not to be linked to the NGF signaling in this chronic pain model.

RESUMO JUSTIFICATIVA E OBJETIVOS: A expressão do fator de crescimento neural (NGF) em neurônios de diâmetro largo pode representar um papel importante na plasticidade sináptica neuronal e na reorganização da função neuronal após lesão neural. A estimulação transcraniana por corrente contínua (ETCC) é um método não invasivo de estimulação cerebral e representa uma ferramenta promissora para o manejo da dor, pois promove neuroplasticidade no sistema central, podendo ser combinada com outras intervenções. O objetivo foi investigar os efeitos da ETCC nos níveis de NGF em estruturas do sistema nervoso central e periférico de ratos submetidos a um modelo de dor neuropática (DN). MÉTODOS: A constrição crônica (CCI) do nervo isquiático foi utilizada para indução do modelo de DN. Na cirurgia sham, o nervo foi exposto, no entanto não houve constrição do nervo. O grupo controle não foi submetido ao procedimento cirúrgico. Após estabelecimento da DN, os grupos tratados foram submetidos a ETCC 0,5 mA/20min/dia/8 dias. Os níveis de NGF no córtex cerebral, medula espinal e nervo isquiático foram mensurados pela técnica de ELISA 48 horas e 7 dias após o final do tratamento. RESULTADOS: O modelo de dor CCI aumentou os níveis de NGF nas três estruturas analisadas, evidenciando a importância desta neurotrofina na dor neuropática. Por outro lado, não houve efeito da ETCC nos níveis de NGF central e periférico, descartando o papel desta neurotrofina no efeito analgésico da ETCC. CONCLUSÃO: Efeitos da ETCC sobre vias nociceptivas não estão diretamente relacionados com a sinalização do NGF neste modelo de dor crônica.

Active post-operative phoned search for late infections of surgical site and thromboembolic events in the late postoperative period of plastic surgeries in a day hospital in the municipality of Porto Alegre

Introduction: Elective and plastic surgical procedures are normally considered safer than emergency surgeries, although they cause concern to health services. The aim of this study was to analyze the active phoned search as a screening instrument for the diagnosis of surgical site infection (SSI) and thromboembolic events (TEs) in the late postoperative care of plastic surgeries in a private day hospital in the city of Porto Alegre. Methods: Quantitative, descriptive, retrospective, cross-sectional study. Data was collected from a database provided by phoned active search of sign and symptoms for epidemiological monitoring by the control infection service of a day-hospital, from July 2015 to February 2017. Results: A total of 3.595 patients were effective contacted in the indicated period. Among these patients, 77.6% received guidance on TEs. Moreover, 0.4% and 0.2% of patients reported signs and symptoms of SSI and TE, respectively. Associated procedures caused 50.0% of SSIs and 87.5% of TEs. Phoned search increased in 0.2% the number of reported cases of both adverse events in the overall sample. Conclusion: SSI and TE are worrying events for health institutions, since they can put patient safety at risk. Therefore, the data obtained in this study were used as a basis to qualify phoned search as an effective screening instrument for SSI and TE and provided support for the development of more consistent phoned search mechanisms for monitoring these postoperative events. (AU)

Interrelação entre síndrome metabólica, estresse crônico e ritmos circadianos de marcadores adipogênicos: uma revisão / Interrelation between metabolic syndrome, chronic stress and circadian rhythms of adipogenic markers: a review

Alterações de ritmos circadianos são relacionadas ao desenvolvimento de transtornos metabólicos como obesidade e síndrome metabólica. Além disto, a disponibilidade e o consumo de alimentos altamente palatáveis ricos em gordura e a exposição a situações estressantes podem contribuir na incidência e na severidade destas doenças crônicas, provocando modificações no balanço energético, alterações no metabolismo de lipídeos e adipogênese. Nesta revisão, abordaremos os aspectos cronobiológicos que podem ser influenciados pela exposição a estresse crônico e a obesidade, além dos mecanismos que contribuem para o crescimento de doenças metabólicas (AU)

Alterations in circadian rhythms are associated with the development of metabolic disorders, such as obesity and metabolic syndrome. Moreover, the availability and consumption of highly palatable foods rich in fat and the exposure to stressful situations may contribute to the incidence and severity of these chronic diseases, leading to changes in energy balance, alterations in lipid metabolism and adipogenesis. This review aimed to discuss the chronobiological aspects that can be influenced by the response to chronic stress and obesity, as well as the mechanisms that contribute to the development of metabolic diseases (AU)