Weight-drop model as a valuable tool to study potential neurobiological processes underlying behavioral and cognitive changes secondary to mild traumatic brain injury.

The pathophysiology of post-traumatic brain injury (TBI) behavioral and cognitive changes is not fully understood, especially in its mild presentation. We designed a weight drop TBI model in mice to investigate the role of neuroinflammation in behavioral and cognitive sequelae following mild TBI. C57BL/6 mice displayed depressive-like behavior at 72 h after mild TBI compared with controls, as indicated by a decrease in the latency to first immobility and climbing time in the forced swim test. Additionally, anxiety-like behavior and hippocampal-associated spatial learning and memory impairment were found in the elevated plus maze and in the Barnes maze, respectively. Levels of a set of inflammatory mediators and neurotrophic factors were analyzed at 6 h, 24 h, 72 h, and 30 days after injury in ipsilateral and contralateral hemispheres of the prefrontal cortex and hippocampus. Principal components analysis revealed two principal components (PC), which represented 59.1% of data variability. PC1 (cytokines and chemokines) expression varied between both hemispheres, while PC2 (neurotrophic factors) expression varied only across the investigated brain areas. Our model reproduces mild TBI-associated clinical signs and pathological features and might be a valuable tool to broaden the knowledge regarding mild TBI pathophysiology as well as to test potential therapeutic targets.

Acute and Chronic Effects of Strength Training on Plasma Levels of Adipokines in Man.

Adipose tissue is specialized cells that produce and release adipokines. Exercise may modulate adipokine production in adipocytes. The aim of this longitudinal study was to evaluate the acute and chronic effects of strength training (ST) on plasma levels of adiponectin, leptin, and resistin. Twelve untrained young male participants (23.42±2.67 years) were selected. The training protocol consisted of 3 exercises, with 3 sets of 65% of 1RM (one-repetition maximum) with pause of 90 s between sets with duration of 5 s/repetition (2 s conc/3 s ecc), 3 times a week for 10 weeks. Blood was collected at four time points: before and after the first ST session and before and after the last ST session. The comparisons between adipokine levels before and after the same training session showed acute changes, while the comparisons between levels before or after the first session versus before or after the last session revealed chronic alterations. ST increased adiponectin levels after the first exercise session in comparison to levels before this session [50 952 (46 568-51 894) pg/mL vs. 52 981 (49 901-54 467) pg/mL, p=0.019]. Similar differences were observed for resistin levels, which were higher after the last session compared to before [4 214.4 (±829) pg/mL vs. pre-S30 2 251.3 (±462.2) pg/mL, p=0.0008] and in the comparison between after the last and after the first ST sessions [4 214.4 (±829.0) pg/mL vs. 1 563.7 (±284.8) pg/mL, p=0.004]. Leptin levels acutely changed in the last training session. ST produced acute and chronic changes in plasma adipokines.

Potential Biomarkers of impulsivity in mild traumatic brain injury: A pilot study.

Very few studies have investigated cognition and impulsivity following mild traumatic brain injury (mTBI) in the general population. Furthermore, the neurobiological mechanisms underlying post-TBI neurobehavioral syndromes are complex and remain to be fully clarified. Herein, we took advantage of machine learning based-modeling to investigate potential biomarkers of mTBI-associated impulsivity. Twenty-one mTBI patients were assessed within one-month post-TBI and their data were compared to 19 healthy controls on measures of impulsivity (Barratt Impulsiveness Scale - BIS), executive functioning, episodic memory, self-report cognitive failures and blood biomarkers of inflammation, vascular and neuronal damage. mTBI patients were significantly more impulsive than controls in BIS total and subscales. Serum levels of sCD40L, Cathepsin D, IL-4, Neuropilin-1, IFN-α2, and Copeptin were associated with impulsivity in mTBI patients. Besides showing that mTBI are associated with impulsivity in non-military people, we unveiled different pathophysiological pathways potentially implicated in mTBI-related impulsivity.

Traumatic brain injury in Brazil: an epidemiological study and systematic review of the literature.

BACKGROUND: Traumatic brain injury (TBI) is a serious public health problem worldwide. Although TBI is common in developing countries, there are few epidemiological studies. OBJECTIVE: To investigate the sociodemographic and clinical features of patients with TBI at the Hospital João XXIII, a public reference center for trauma in Belo Horizonte, Brazil, and to systematically review the available literature on TBI in Brazil. METHODS: Clinical and sociodemographic data were collected from electronic medical records for the entire month of July 2016. The literature on epidemiology of TBI in Brazil was systematically reviewed using MeSH/DeCS descriptors in the PubMed and Lilacs databases. RESULTS: Most patients admitted with TBI were male and under 60 years of age. Mild TBI was the most prevalent form and the most common cause of TBI was falls. A Glasgow Coma Scale score below 12, neuroimaging changes on computer tomography, and presence of any medical conditions were significantly associated with longer hospital stay. Brazilian studies showed that TBI affected mainly men and young adults. In addition, mild TBI was the most common TBI severity reported and the most common causes were motor vehicle accidents and falls. CONCLUSIONS: Overall, the profile of TBI in this center reflects the data from other Brazilian studies.

Traumatic brain injury in Brazil: an epidemiological study and systematic review of the literature / Traumatismo cranioencefálico no Brasil: um estudo epidemiológico e uma revisão sistemática da literatura

ABSTRACT Background: Traumatic brain injury (TBI) is a serious public health problem worldwide. Although TBI is common in developing countries, there are few epidemiological studies. Objective: To investigate the sociodemographic and clinical features of patients with TBI at the Hospital João XXIII, a public reference center for trauma in Belo Horizonte, Brazil, and to systematically review the available literature on TBI in Brazil. Methods: Clinical and sociodemographic data were collected from electronic medical records for the entire month of July 2016. The literature on epidemiology of TBI in Brazil was systematically reviewed using MeSH/DeCS descriptors in the PubMed and Lilacs databases. Results: Most patients admitted with TBI were male and under 60 years of age. Mild TBI was the most prevalent form and the most common cause of TBI was falls. A Glasgow Coma Scale score below 12, neuroimaging changes on computer tomography, and presence of any medical conditions were significantly associated with longer hospital stay. Brazilian studies showed that TBI affected mainly men and young adults. In addition, mild TBI was the most common TBI severity reported and the most common causes were motor vehicle accidents and falls. Conclusions: Overall, the profile of TBI in this center reflects the data from other Brazilian studies.

RESUMO Antecedentes: O traumatismo cranioencefálico (TCE) representa, mundialmente, um problema sério de saúde pública. Apesar de o TCE ser prevalente em países em desenvolvimento, estudos epidemiológicos permanecem escassos. Objetivo: Investigar as características sociodemográficas e clínicas de pacientes acometidos por TCE no Hospital João XXIII - centro de referência em trauma situado em Belo Horizonte, Brasil - e revisar sistematicamente toda a literatura disponível sobre o TCE no Brasil. Métodos: Os dados clínicos e sociodemográficos foram coletados apenas para o mês de julho, 2016, por meio de prontuários eletrônicos. A literatura sobre a epidemiologia do TCE no Brasil foi sistematicamente revisada usando descritores Medical Subject Headings (MeSH)/Descritores em Ciências da Saúde (DeCS) nos bancos de dados PubMed e Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs). Resultados: Os pacientes acometidos por TCE eram em sua maioria homens com menos de 60 anos. O TCE leve foi a gravidade mais prevalente entre os casos. O TCE foi causado principalmente por quedas. Escores menores que 12 na escala de Coma de Glasgow mais alterações de neuroimagem em tomografia computadorizada e a presença de qualquer comorbidade médica estão significativamente associados à maior estadia hospitalar. Estudos brasileiros demonstraram que o TCE acomete principalmente homens e adultos jovens. Além disso, o TCE leve foi a gravidade mais comum reportada, e os mecanismos de TCE mais comuns foram acidentes automobilísticos e quedas. Conclusões: O perfil de pacientes acometidos por TCE no centro de referência em questão reflete os dados de outros estudos brasileiros.

The potential role of renin-angiotensin system in mild traumatic brain injury.

Traumatic brain injury (TBI) is a serious public health problem, affecting 69 million people worldwide annually. Mild TBI (mTBI) comprises the majority of the cases and remains the most neglected TBI severity. Its intricate pathophysiology involves complex cellular and molecular processes that remain uncomprehended. Although the renin-angiotensin system (RAS) has its well-known roles in blood pressure regulation and fluid balance, accumulating evidence demonstrates its active expression and signaling in the central nervous system. Over the past years, pre-clinical studies have been supporting the role of RAS in mTBI. However, particularly for human TBI, evidence is still missing. Herein, we investigated peripheral levels of angiotensin II (Ang II) and angiotensin-converting enzyme (ACE), components of RAS classical axis, as well as angiotensin-(1-7) [Ang-(1-7)] and ACE2, components of RAS counter-regulatory axis, in 28 mTBI patients and 24 healthy controls. In the first 24 h, mTBI patients displayed lower ACE (p = 0.0004) and ACE2 (p = 0.0047) concentrations and an increase in Ang II (p = 0.0234) and Ang-(1-7) (p = 0.0225) levels compared to controls. Interestingly, at 30 days follow-up, mTBI patients increased the levels of ACE (p = 0.0415) and ACE2 (p = 0.0416) along with a decrease in Ang II (p = 0.0039) and Ang-(1-7) (p = 0.0015) concentrations compared with their measures at 24 h after TBI. Also, our receiver operating curve (ROC) analysis demonstrated that ACE concentration was a good predictor of mTBI diagnosis (AUC = 0.798, p < 0.0001). The current study provides the first clinical evidence of RAS molecule's involvement in mTBI and their possible role as discriminating biomarkers.

Potential Role of Adult Hippocampal Neurogenesis in Traumatic Brain Injury.

Traumatic brain injury (TBI) is a serious cause of disability and death among young and adult individuals, displaying complex pathophysiology including cellular and molecular mechanisms that are not fully elucidated. Many experimental and clinical studies investigated the potential relationship between TBI and the process by which neurons are formed in the brain, known as neurogenesis. Currently, there are no available treatments for TBI's long-term consequences being the search for novel therapeutic targets, a goal of highest scientific and clinical priority. Some studies evaluated the benefits of treatments aimed at improving neurogenesis in TBI. In this scenario, herein, we reviewed current pre-clinical studies that evaluated different approaches to improving neurogenesis after TBI while achieving better cognitive outcomes, which may consist in interesting approaches for future treatments.

Traumatic brain injury biomarkers in pediatric patients: a systematic review.

Traumatic brain injury (TBI) is the main cause of pediatric trauma death and disability worldwide. Recent studies have sought to identify biomarkers of TBI for the purpose of assessing functional outcomes. The aim of this systematic review was to evaluate the utility of TBI biomarkers in the pediatric population by summarizing recent findings in the medical literature. A total of 303 articles were retrieved from our search. An initial screening to remove duplicate studies yielded 162 articles. After excluding all articles that did not meet the inclusion criteria, 56 studies were gathered. Among the 56 studies, 36 analyzed serum biomarkers; 11, neuroimaging biomarkers; and 9, cerebrospinal fluid (CSF) biomarkers. Most studies assessed biomarkers in the serum, reflecting the feasibility of obtaining blood samples compared to obtaining CSF or performing neuroimaging. S100B was the most studied serum biomarker in TBI, followed by SNE and UCH-L1, whereas in CSF analysis, there was no unanimity. Among the different neuroimaging techniques employed, diffusion tensor imaging (DTI) was the most common, seemingly holding diagnostic power in the pediatric TBI clinical setting. The number of cross-sectional studies was similar to the number of longitudinal studies. Our data suggest that S100B measurement has high sensitivity and great promise in diagnosing pediatric TBI, ideally when associated with head CT examination and clinical decision protocols. Further large-scale longitudinal studies addressing TBI biomarkers in children are required to establish more accurate diagnostic protocols and prognostic tools.

Role of cytokine and neurotrophic factors in nicotine addiction in the conditioned place preference paradigm.

The mechanisms involved in the maintenance of cigarette smoking and nicotine reward remain unclear. Immune response might play an important role in this context. Nicotine may induce both central and systemic inflammatory responses as well as changes in the regulation of brain-derived neurotrophic factor (BDNF). The conditioned place preference (CPP) is a method used for the evaluation of nicotine-induced reward, reproducing nicotine-seeking behavior in humans. So far, there are no studies investigating the relationship between neuroinflammation and nicotine-induced CPP. This study aimed to evaluate the levels of inflammatory mediators and neurotrophic factors in key areas of the central nervous system (CNS) of mice subject to nicotine-induced CPP. CPP was induced with an intraperitoneal administration of 0.5 mg/kg of nicotine in male Swiss mice, using an unbiased protocol. Control group received vehicle by the same route. The levels of cytokines, chemokines, and neurotrophic factors were measured using Enzyme-Linked Immunosorbent Assay (ELISA) in the brain after CPP test. As expected, nicotine induced place preference behavior. In parallel, we observed increased peripheral levels of IL-6 and IL-10 alongside increased hippocampal levels of NGF but decreased GDNF in mice treated with nicotine compared to controls. In the striatum, nicotine promoted decrease of IL-1ß, IL-10 and GDNF levels, while the levels of all the mediators were similar between groups in the pre-frontal cortex. Our results provide evidence on the role of cytokines and neurotrophic factors in nicotine-induced CPP in mice.

Toxoplasma gondii infection and chronic schizophrenia: is there any association?

ABSTRACT Background: Toxoplasma gondii (T. gondii) infection has been identified as a risk factor for schizophrenia. Objectives: Herein, we sought to evaluate the association between T. gondii infection and clinical symptoms and quality of life in patients with schizophrenia. Methods: We conducted a cross-sectional study with 48 patients with chronic schizophrenia and 40 controls. Peripheral blood was drawn, and IgM and IgG anti-T. gondii antibodies were evaluated by Enzyme-Linked Immunosorbent Assay (ELISA). Depressive, positive and negative symptoms were assessed, respectively, by the Calgary Depression Scale (CDS) and the Positive and Negative Syndrome Scale (PANSS). Cognitive performance was assessed in patients by the Brazilian version of the Schizophrenia Cognition Rating Scale (SCoRS-BR). Quality of life was assessed by the Brazilian version of the Quality of Life in Schizophrenia scale (QLS-BR). Results: The prevalence and titers of T. gondii IgM and IgG antibodies did not differ between patients and controls. The positive serology for T. gondii IgG antibodies was not associated with illness symptoms, cognitive performance, depressive symptoms or quality of life. Discussion: Our findings suggest that toxoplasmosis infection is not associated with severity of symptoms, quality of life, cognitive or depressive symptoms in schizophrenia patients.

Is there any association between Toxoplasma gondii infection and bipolar disorder? A systematic review and meta-analysis.

BACKGROUND: The relationship between Toxoplasma gondii infection and the development of bipolar disorder (BD) has long been investigated, yet to date it is still poorly understood and documented. The aim of this review is to derive a summary estimate of the strength of the association between infection with T. gondii and BD from the available published studies. METHODS: A systematic review was performed using PubMed, LILACS, PsycINFO, and Embase databases. Studies which included a proportion of seropositive BD patients and controls were further examined in a meta-analysis. RESULTS: One hundred eighteen citations were initially retrieved. Thirteen studies were included in our systematic review. Eight out of these thirteen studies were included in our meta-analysis. Statistical analyses showed that T. gondii infection is associated with with BD (OR=1.26). LIMITATIONS: Small sample size was the major limitation among the studies that carried out serological analyses. In addition, the available studies did not have enough information on disease status/severity or type of bipolar disorder. Also, it was not possible to analyze pregnancy status or perinatal infection. Future studies addressing the aforementioned topics are clearly needed. CONCLUSIONS: Despite heterogeneous results, patients with BD are more likely to be infected by T. gondii than controls. Early T. gondii infection might predispose the development of BD. T.gondii infection is becoming clinically relevant in psychiatric disorders and future mechanistic studies are required to elucidate the underlying pathophysiological mechanisms.