RESUMO
Sepsis causes overproduction of inflammatory cytokines, organ dysfunction, and cognitive impairment in survivors. In addition to inflammation, metabolic changes occur according to the stage and severity of the disease. Understanding the role and place of metabolic disturbances in the pathophysiology of sepsis is essential to evaluate the framework of septic patients, predict the syndrome progress, and define the treatment strategies. We investigated the effect of simvastatin on the disease time course and on metabolic alterations, especially with respect to their possible consequences in the CNS of surviving rats. The animals of this study were weighed daily and followed for 10 days to determine the survival rate. In the first experiment, control or cecal ligation and puncture (CLP)-animals were randomized in 24 h, 48 h, and 10 days after septic induction, for bacterial load determination and quantification of cytokines. In the second experiment, control or CLP-animals were treated or not with simvastatin and randomized in the same three time points for cytokines quantification and assessment of their body metabolism and locomotor activity (at 48 h and 10 days), as well as the evaluation of cytoarchitecture and astrogliosis (at 10 days). The CLP-rats treated with simvastatin showed a reduction in plasma cytokines and improvement in metabolic parameters and locomotor activity, followed by minor alterations compatible with apoptosis and astrogliosis in the hippocampus and prefrontal cortex. These results suggest that the anti-inflammatory effect of simvastatin plays a crucial role in restoring energy production, maintaining a hypermetabolic state necessary for the recovery and survival of these CLP-rats.
Assuntos
Sepse , Sinvastatina , Animais , Ratos , Citocinas/metabolismo , Modelos Animais de Doenças , Gliose , Sepse/tratamento farmacológico , Sinvastatina/farmacologia , SobreviventesRESUMO
BACKGROUND: Clinical and experimental studies report a dysregulation of hypothalamus-pituitary-adrenal (HPA) axis during sepsis that causes impairment in hormone secretion in the late phase contributing for the pathophysiology of the disease. However, it is unclear whether this alteration persists even after the disease remission. METHODS: We evaluated the effect of an immune challenge or restraint stress on the hormone secretion of HPA axis in sepsis survivor rats. Sepsis was induced by cecal ligation-puncture (CLP) surgery. Naive or animals that survive 5 or 10 days after CLP were submitted to lipopolysaccharide (LPS) injection or restraint stress. After 60 min, blood was collected for plasma nitrate, cytokines, adrenocorticotropic hormone (ACTH), and corticosterone (CORT) and brain for synaptophysin and hypothalamic cytokines. RESULTS: Five days survivor animals showed increased plasma nitrate (p < 0.001) and interleukin (IL)-1ß levels (p < 0.05) that were abolished in the 10 days survivors. In the hypothalamus of both survivors, the reverse was seen with IL-6 increased (p < 0.01), while IL-1ß did not show any alteration. Synaptophysin expression was reduced in both survivors and did not change after any stimuli. Only the LPS administration increased plasma and/or inflammatory mediators levels in both groups (survivors and naive) being apparently lower in the survivors. There was no difference in the increased secretion pattern of ACTH and CORT observed in the naive and sepsis survivor animals submitted to immune challenge or restraint stress. CONCLUSION: We conclude that the HPA axis is already recovered soon after 5 days of sepsis induction responding with normal secretion of ACTH and CORT when required.
Assuntos
Corticosterona , Sepse , Animais , Ratos , Hormônio Adrenocorticotrópico , Sistema Hipotálamo-Hipofisário/metabolismo , Lipopolissacarídeos/toxicidade , Nitratos/metabolismo , Nitratos/farmacologia , Sistema Hipófise-Suprarrenal , Ratos Wistar , Sepse/metabolismo , Sobreviventes , Sinaptofisina/metabolismo , Sinaptofisina/farmacologiaRESUMO
ABSTRACT: Healthy cattle are considered the main reservoir of Shiga toxin-producing Escherichia coli (STEC) strains, so in some places in the world, products derived from beef are the most common source for disease outbreaks caused by these bacteria. Therefore, to guarantee that the beef produced by our slaughterhouses is safe, there is a need for continuous monitoring of these bacteria. In this study, 215 beef cuts were evaluated, including chilled vacuum-packed striploins (151 samples), rib eyes (30 samples), and knuckles (34 samples), from March to June 2018. These meat samples were collected from the slaughter of unconfined cattle, being arbitrarily collected from eight meat processing companies in São Paulo state, Brazil. Each sample was examined for the presence of STEC toxin type (stx1 and/or stx2 genes) and also the attaching and effacing E. coli (eae) gene, determined by a multiplex PCR assay. We show that the major seven STEC strains (O serogroups O26, O45, O103, O111, O121, O145, and O157) are not detected in any of the analyzed beef cut samples; however, three of them presented the virulence eae gene. Therefore, the absence of STEC strains in the beef samples may be an indication of the low prevalence of this pathogen in the cattle herd on the farm, associated with good hygiene and handling practices adopted by the meat industry.
Assuntos
Proteínas de Escherichia coli , Escherichia coli Shiga Toxigênica , Matadouros , Animais , Brasil , Bovinos , Proteínas de Escherichia coli/genética , Carne/microbiologia , Sorogrupo , Escherichia coli Shiga Toxigênica/genéticaRESUMO
Sepsis promotes an inflammatory state in the central nervous system (CNS) that may cause autonomic, cognitive, and endocrine changes. Microglia, a resident immune cell of the CNS, is activated in several brain regions during sepsis, suggesting its participation in the central alterations observed in this disease. In this study, we aimed to investigate the role of microglial activation in the neuroendocrine system functions during systemic inflammation. Wistar rats received an intracerebroventricular injection of the microglial activation inhibitor minocycline (100 µg/animal), shortly before sepsis induction by cecal ligation and puncture. At 6 and 24 h after surgery, hormonal parameters, central and peripheral inflammation, and markers of apoptosis and synaptic function in the hypothalamus were analyzed. The administration of minocycline decreased the production of inflammatory mediators and the expression of cell death markers, especially in the late phase of sepsis (24 h). With respect to the endocrine parameters, microglial inhibition caused a decrease in oxytocin and an increase in corticosterone and vasopressin plasma levels in the early phase of sepsis (6 h), while in the late phase, we observed decreased oxytocin and increased ACTH and corticosterone levels compared to septic animals that did not receive minocycline. Prolactin levels were not affected by minocycline administration. The results indicate that microglial activation differentially modulates the secretion of several hormones and that this process is associated with inflammatory mediators produced both centrally and peripherally.
Assuntos
Corticosterona/sangue , Microglia/metabolismo , Ocitocina/sangue , Sepse/metabolismo , Vasopressinas/sangue , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Microglia/efeitos dos fármacos , Minociclina/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Sistemas Neurossecretores/metabolismo , Ratos , Ratos WistarRESUMO
Sepsis-associated encephalopathy causes brain dysfunction that can result in cognitive impairments in sepsis survivor patients. In previous work, we showed that simvastatin attenuated oxidative stress in brain structures related to memory in septic rats. However, there is still a need to evaluate the long-term impact of simvastatin administration on brain neurodegenerative processes and cognitive damage in sepsis survivors. Here, we investigated the possible neuroprotective role of simvastatin in neuroinflammation, and neurodegeneration conditions of brain structures related to memory in rats at 10 days after sepsis survival. Male Wistar rats (250-300 g) were submitted to cecal ligation and puncture (CLP, n = 42) or remained as non-manipulated (naïve, n = 30). Both groups were treated (before and after the surgery) by gavage with simvastatin (20 mg/kg) or an equivalent volume of saline and observed for 10 days. Simvastatin-treated rats that survived to sepsis showed a reduction in the levels of nitrate, IL1-ß, and IL-6 and an increase in Bcl-2 protein expression in the prefrontal cortex and hippocampus, and synaptophysin only in the hippocampus. Immunofluorescence revealed a reduction of glial activation, neurodegeneration, apoptosis, and amyloid aggregates confirmed by quantification of GFAP, Iba-1, phospho Ser396-tau, total tau, cleaved caspase-3, and thioflavin-S in the prefrontal cortex and hippocampus. In addition, treated animals presented better performance in tasks involving habituation memory, discriminative, and aversive memory. These results suggest that statins exert a neuroprotective role by upregulation of the Bcl-2 and gliosis reduction, which may prevent the cognitive deficit observed in sepsis survivor animals.
Assuntos
Encéfalo/efeitos dos fármacos , Disfunção Cognitiva/prevenção & controle , Doenças Neurodegenerativas/tratamento farmacológico , Sepse/tratamento farmacológico , Sinvastatina/uso terapêutico , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Masculino , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Ratos , Ratos Wistar , Sepse/metabolismo , Sepse/patologia , Sinvastatina/farmacologiaRESUMO
Sepsis-associated encephalopathy (SAE) is a significant problem in patients with sepsis, and it is associated with a decrease in cognitive and sensitivity capability induced by systemic inflammation. SAE is implicated in reversible brain damage of several regions related to cognition, emotion, and sensation; however, it is not well established if it could affect brain regions associated with nociceptive modulation. Here were evaluated the nociceptive thresholds in rats with systemic inflammation induced by cecal ligation puncture (CLP). After 24 h of CLP, it was observed an increase in nociceptive threshold in all tests. Periaqueductal gray, rostroventral medulla, critical regions for descending nociceptive modulation, were evaluated and showed enhanced pro-inflammatory cytokines as well as glial activation. These results suggest that systemic inflammation could compromise descending facilitatory pathways, impairing nociceptive sensory functioning.
RESUMO
OBJECTIVE: To evaluate the contamination rate of hamstring tendon autografts by comparing two different techniques, and to verify whether intraoperative contamination is associated with the development of clinical infection in patients submitted to reconstruction of the anterior cruciate ligament (ACL). METHODS: A total of 110 hamstring tendon autograft ACL reconstructions were performed and divided into two groups: 1-hamstring tendon retraction technique; and 2 - technique maintaining the tibial insertion of the hamstring tendon. During the preparation, two graft fragments were sent for culturing; the harvesting time, the preparation time, and the total surgery time were measured. Twenty-four hours after the surgery, the C-reactive protein was assayed. The clinical outpatient follow-up was performed up to 180 days postoperatively. RESULTS: Although there were two postoperative infections, there was no graft contamination or difference between the groups in relation to the graft preparation time and to the 24-hour postoperative C-reactive protein assessment. The classic technique presented a longer graft harvesting time ( p = 0.038), and there was no statistical difference between the 2 groups regarding the degree of contamination and consequent clinical infection, although 2 patients in group 2 presented with infection, with negative perioperative cultures. CONCLUSION: Based on the results obtained, there was no association between graft contamination and the time or technique of its preparation. In addition, there was also no association between intraoperative contamination and the development of clinical infection, nor was there any sign of an association between the early alteration of C-reactive protein and the onset of infection.
RESUMO
In hydrocephalus, the progressive accumulation of cerebrospinal fluid (CSF) causes dilatation of the lateral ventricles affecting the third ventricle and diencephalic structures such as the hypothalamus. These structures play a key role in the regulation of several neurovegetative functions by the production of the hormones. Since endocrine disturbances are commonly observed in hydrocephalic children, we investigated the impact of progressive ventricular dilation on the hypothalamus of infant rats submitted to kaolin-induced hydrocephalus. Seven-day-old infant rats were submitted to hydrocephalus induction by kaolin 20% injection method. After 14â¯days, the animals were decapitated and brain was collected to analyze mitochondrial function, neuronal activity by acetylcholinesterase (AChE) enzyme, oxidative damage, glial activation, and, neurotransmission-related proteins and anti-apoptotic processes in the hypothalamus. The hydrocephalic animals showed reduction in respiratory rates in the States of phosphorylation (Pâ¯<â¯0.01) and non-phosphorylation (Pâ¯<â¯0.05); increase in AChE activity in both the cytosol (Pâ¯<â¯0.05) and the membrane (Pâ¯<â¯0.01); decrease in synaptophysin (Pâ¯<â¯0.05) and Bcl-2 (Pâ¯<â¯0.05) contents and; increase in protein carbonyl (Pâ¯<â¯0.01), GFAP (Pâ¯<â¯0.01) and Iba-1 (Pâ¯<â¯0.05) levels. The results demonstrate that ventricular dilation causes hypothalamic damage characterized by cholinergic dysfunction and suggests further investigation of the synthesis and secretion of hormones to generate new approaches and to assist in the treatment of hydrocephalic patients with hormonal alterations.
Assuntos
Acetilcolinesterase/metabolismo , Hidrocefalia/metabolismo , Hipotálamo/fisiopatologia , Acetilcolinesterase/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/fisiopatologia , Ventrículos Cerebrais/fisiopatologia , Modelos Animais de Doenças , Hidrocefalia/fisiopatologia , Hipotálamo/metabolismo , Caulim/efeitos adversos , Caulim/farmacologia , Ventrículos Laterais/fisiopatologia , Masculino , Neurônios , Ratos , Ratos WistarRESUMO
Previous studies have shown that in the early phase of sepsis, the plasma concentration of arginine vasopressin (AVP) is increased, but in the late phase, its levels remain inadequately low, despite of persistent hypotension. One hypothesis suggested for this relative deficiency is apoptosis of vasopressinergic neurons. Here, we investigated apoptosis pathways in the hypothalamus during sepsis, as well as mechanisms underlying this process. Male Wistar rats were submitted to sepsis by cecal ligation and puncture (CLP) or nonmanipulated (naive) as control. After 6 and 24 h, the animals were decapitated and brain and blood were collected to assess hypothalamic apoptotic markers, IFN-γ plasma levels, and evidence for breakdown of the blood-brain barrier (BBB). Sepsis caused a decrease in mitochondrial antiapoptotic proteins (Bcl-2, Bcl-xL) in the hypothalamus, but had no effect on markers of cell death mediated by death receptors or immune cells. In the supraoptic nuclei of these animals, microglia morphology was consistent with activation, associated with an increase in plasma IFN-γ. A transitory breakdown of BBB in the hypothalamus was seen at 6 h following CLP. The results indicate that the intrinsic but not extrinsic apoptosis pathway is involved in the cell death observed in vasopressinergic neurons, and that this condition is temporally associated with microglial activation and BBB leaking.
Assuntos
Apoptose/fisiologia , Arginina Vasopressina/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Sepse/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Hipotálamo/efeitos dos fármacos , Masculino , Óxido Nítrico/metabolismo , Ratos WistarRESUMO
During sepsis, brain damage is associated with oxidative stress due to overproduction of reactive oxygen species (ROS). Although there are recent reports about the benefits of statins in experimental sepsis and endotoxemia in peripheral organs, little is known about their effects in the CNS. Here, we investigated the antioxidant properties of simvastatin and its possible neuroprotective role during experimental sepsis. Male Wistar rats (250-300 g) were submitted to cecal ligation and puncture (CLP, n = 34) or remained as non-manipulated (naive, n = 34). Both groups were treated by gavage with simvastatin (20 mg/kg) or an equivalent volume of saline. The animals submitted to CLP were treated 4 days before and 48 h after surgery. One animal group was decapitated and the blood and brain were collected to quantify plasma levels of cytokines and assess astrogliosis and apoptosis in the prefrontal cortex and hippocampus. Another group was perfused with PBS (0.01 M), and the same brain structures were dissected to analyze oxidative damage. The CLP rats treated with simvastatin showed a reduction in nitric oxide (P < 0.05), IL1-ß (P < 0.001), IL-6 (P < 0.01), and TBARS levels (P < 0.001) and an increase in catalase activity (P < 0.01), citrate synthase enzyme (P < 0.05), and normalized GSH/GSSG ratio. In addition, the histopathological analysis showed a reduction (P < 0.001) in reactive astrocytes and caspase 3-positive apoptotic cells. The results suggest a possible neuroprotective effect of simvastatin in structures responsible for spatial learning and memory and indicate the need for behavioral studies evaluating the impact on cognitive damage, as frequently seen in patients surviving sepsis.