ABSTRACT
ABSTRACT There is growing evidence suggesting an association between neurodegeneration and inflammation playing a role in the pathogenesis of age-associated diseases, including Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). Objective: A systematic review and meta-analysis were performed to verify evidence on the diagnostic accuracy parameters of the inflammatory cytokines interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor alpha (TNF-α). Methods: A search of Medical Literature Analysis and Retrieval System Online (Medline), Scientific Electronic Library Online (SciELO), Web of Science and Science Direct databases was performed and nine observational studies associated with peripheral inflammatory biomarkers in MCI were identified. Mean (±standard deviation — SD) concentrations of these biomarkers and values of true positives, true negatives, false positives and false negatives for MCI and healthy controls (HC) were extracted from these studies. Results: Significantly higher levels of IL-10 were observed in subjects in the MCI group and Mini-Mental State Examination (MMSE) scores were lower compared to HC. For the other investigations, no differences were found between the groups. Our meta-analysis for the TNF-α biomarker revealed high heterogeneity between studies in terms of sensitivity and specificity. Conclusion: These findings do not support the involvement of inflammatory biomarkers for detection of MCI, although significant heterogeneity was observed. More studies are needed to evaluate the role of these cytokines in MCI, as well as in other stages of cognitive decline and all-cause dementias.
RESUMO Há evidências crescentes que sugerem uma associação entre a neurodegeneração e a inflamação, desempenhando um papel na patogênese de doenças associadas à idade, incluindo a doença de Alzheimer (DA) e o comprometimento cognitivo leve (CCL). Objetivo: Uma revisão sistemática e metanálise foram realizadas para verificar evidências relativas aos parâmetros de acurácia diagnóstica das citocinas inflamatórias interleucina-6 (IL-6), interleucina-10 (IL-10) e fator de necrose tumoral (TNF-α). Métodos: Foi realizada uma busca nas bases de dados Medical Literature Analysis and Retrieval System Online (Medline), Scientific Electronic Library Online (SciELO), Web of Science e Science Direct, e foram identificados nove estudos observacionais associados a biomarcadores inflamatórios periféricos no CCL. As concentrações médias (desvio padrão — ±DP) desses biomarcadores e valores de verdadeiros positivos, verdadeiros negativos, falsos positivos e falsos negativos para CCL e controles saudáveis (CS) foram extraídos desses estudos. Resultados: Níveis significativamente mais elevados de IL-10 foram observados em indivíduos do grupo CCL e os escores do Miniexame do Estado Mental foram mais baixos em comparação com o CS. Para as demais investigações não foram encontradas diferenças entre os grupos. Nossa metanálise para o biomarcador TNF-α revelou alta heterogeneidade entre os estudos em termos de sensibilidade e especificidade. Conclusão: Esses achados não apoiam o envolvimento de biomarcadores inflamatórios na detecção do CCL, embora tenha sido observada heterogeneidade significativa. Mais estudos são necessários para avaliar o papel dessas citocinas no CCL, bem como em outros estágios de declínio cognitivo e demências de todas as causas.
ABSTRACT
Abstract Background Hadruroides lunatus is the most abundant scorpion species in the Peruvian central coast, where most of the accidents involving humans are registered. In spite of its prevalence, there are only very few studies on H. lunatus envenomation. The aim of the present study was to analyze the cardiorespiratory alterations caused by H. lunatus envenomation in rodents. Methods Wistar rats injected with H. lunatus scorpion venom were submitted to electrocardiography. After euthanasia, rat lungs were collected and histopathologically analyzed. Mouse cardiomyocytes were used to perform immunofluorescence and calcium transient assays. Data were analyzed by ANOVA or Students t-test. The significance level was set at p 0.05. Results It was observed that H. lunatus venom increased heart rate and caused arrhythmia, thereby impairing the heart functioning. Lungs of envenomed animals showed significant alterations, such as diffuse hemorrhage. In addition, immunofluorescence showed that H. lunatus venom was capable of binding to cardiomyocytes. Furthermore, mouse ventricular cardiomyocytes incubated with H. lunatus venom showed a significant decrease in calcium transient, confirming that H. lunatus venom exerts a toxic effect on heart. Conclusion Our results showed that H. lunatus venom is capable of inducing cardiorespiratory alterations, a typical systemic effect of scorpionism, stressing the importance of medical monitoring in envenomation cases.
ABSTRACT
Abstract Background Hadruroides lunatus is the most abundant scorpion species in the Peruvian central coast, where most of the accidents involving humans are registered. In spite of its prevalence, there are only very few studies on H. lunatus envenomation. The aim of the present study was to analyze the cardiorespiratory alterations caused by H. lunatus envenomation in rodents. Methods Wistar rats injected with H. lunatus scorpion venom were submitted to electrocardiography. After euthanasia, rat lungs were collected and histopathologically analyzed. Mouse cardiomyocytes were used to perform immunofluorescence and calcium transient assays. Data were analyzed by ANOVA or Student’s t-test. The significance level was set at p< 0.05. Results It was observed that H. lunatus venom increased heart rate and caused arrhythmia, thereby impairing the heart functioning. Lungs of envenomed animals showed significant alterations, such as diffuse hemorrhage. In addition, immunofluorescence showed that H. lunatus venom was capable of binding to cardiomyocytes. Furthermore, mouse ventricular cardiomyocytes incubated with H. lunatus venom showed a significant decrease in calcium transient, confirming that H. lunatus venom exerts a toxic effect on heart. Conclusion Our results showed that H. lunatus venom is capable of inducing cardiorespiratory alterations, a typical systemic effect of scorpionism, stressing the importance of medical monitoring in envenomation cases.