Efeito da laserterapia na viabilidade de macrófagos e sua produção de óxido nítrico frente a cimentos endodônticos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise dos macrófagos M1 e M2 durante a infecção por Sporothrix schenckii em modelo murino

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modulação nitrérgica na regulação ocitocinérgica da secreção do peptídeo natriurético atrial em cardiomiócitos

Historicamente conhecida por suas ações sobre o sistema reprodutor, hoje se sabe que a ocitocina (OT) também pode contribuir para a regulação da homeostase cardiovascular e hidroeletrolítica. A OT é produzida nos núcleos supra-óptico e paraventricular do hipotálamo e liberada para o plasma a partir de terminais neurais da pituitária posterior, no entanto, muitos estudos identificaram locais extra-cerebrais de produção OT, incluindo o coração e o endotélio vascular. A ativação de seus receptores em células endoteliais, bem como em sistemas hipotalâmicos/hipofisários e cardíaco, pode resultar na produção de óxido nítrico (NO). O presente trabalho teve como objetivo verificar o papel do NO na regulação da secreção de peptídeo natriurético atrial (ANP) estimulada por OT em cultura primária de cardiomiócitos de embriões de camundongos. Para tal, corações de embriões de camundongos Balb C, com 19 a 21 dias de vida intra-uterina, foram isolados e cultivados para os ensaios com OT e demais substâncias interferentes na síntese de NO e GMPc seu segundo mensageiro. A adição de concentrações crescentes de OT (0.1, 1, 10 e 100 μM) induziu aumento proporcional na secreção de ANP e nitrato para o meio, confirmando a ação estimuladora da OT em cardiomiócitos. O bloqueio da liberação de ANP estimulada por OT (10 μM) foi observada após adição de Ornitina Vasotocina (CVI-OVT) (100 μM), um antagonista específico de OT. Este antagonista inibiu a secreção basal de ANP, quando adicionado individualmente, sugerindo que a OT pode atuar via mecanismo autócrino, tônico estimulatório sobre a secreção de ANP. Amplificação da secreção de ANP estimulada por OT (10 μM) foi observada após sua associação com L-NAME, um inibidor da sintase de óxido nítrico (NOS) (600 μM), e ODQ (100 μM), um inibidor da guanilato ciclase solúvel, sugerindo a ocorrência de feedback negativo nitrérgico na liberação de ANP estimulada por OT no cardiomiócito. Os resultados obtidos mostraram modulação nitrérgica inibidora sobre a secreção de ANP estimulada por OT.

Effect of Qualea multiflora on Macrophages and Tumour Cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Funcionalização de celulose bacteriana com peptídeo RGD para reparação tecidual de pele

Pós-graduação em Química - IQ

The role of qualea multiflora on mammary tumour cells and immune system

Species of the genus Qualea are used by the Brazilian public as a natural anti-inflammatory. Based on this evidence, we evaluated the effects of terpene fractions (βF and TF) obtained from Qualea multiflora on nitric oxide production (Griess assay), cytokines (IL-1, IL-10, IL-12, and TNF-a) and the transcription factor NF-κB by peritoneal macrophages. Since there is a relationship between inflammation and cancer, the cytotoxicity of βF and TF against mammary tumoural cell lineage, and macrophages was evaluated. Inhibition levels close to 90% of the production of NO, IL-1, IL-12 and TNF-a; about 32% of NF-κB; and a large stimulation of IL-10 production (close to the positive control) by peritoneal macrophages were observed in response to βF and TF which are correlated with anti-inflammatory activity. Additionally, the samples showed exceptional cytotoxic activity against tumoural cells but not against macrophages. Since anti-inflammatory activity is important in tumour inhibition, further examination of potential anti-cancerous activity of Qualea multiflora is warranted.

Understanding the influence of oxidative stress and physical exercise in the relationship between blood pressure and uric acid

Due to the high incidence and prevalence of hypertension, especially in the elderly population, several studies have been developed to understand the relationship between etiological factors and blood pressure control. It has been demonstrated that hypertensive patients tend to present a status of hyperuricemia. This result suggested that there is a relationship between blood pressure and uric acid concentrations. However there is still a lack of studies that focus on this relationship, and especially how physical exercise could affect the relationship between both of them. Thus, the purpose of this study is to review and discuss the relationship between hypertension and uric acid concentration pointing the oxidative stress as the main factor of this relationship and discuss the physical exercise as the main preventive factor of high uric acid concentrations and oxidative stress. It has been described an increase in oxidative stress during the uric acid pathway because the high production of anions superoxide. This in turn, increases the activation of renin-angiotensin system and decreases nitric oxide bioavailability which will compromise the vasodilatation mechanism. However physical exercises have been associated with improvements in antioxidant capacity and nitric oxide production and bioavailability which will improve the blood pressure control.

Metodologia da criação de Galleria mellonella para uso como modelo de infecção e efeitos de Lactobacillus rhamnosus inativado pelo calor in vivo e in vitro, desafiados por Staphylococcus aureus e Escherichia coli

Pós-graduação em Biopatologia Bucal - ICT

Does orchiectomy enhance the immune-stimulatory effects of melatonin during experimental Chagas' disease?

Melatonin has been reported to play a fundamental role in T-cell immunoregulation. Control of Trypanosome cruzi parasitism during the acute phase of infection is considered to be critically dependent on direct macrophage activation by cytokines. The aim of this work was to evaluate the influence of exogenous melatonin treatment and the influences exerted by sexual hormones during the acute phase of the experimental Chagas' disease in rats. With melatonin treatment, orchiectomized animals (CMOR and IMOR) displayed the highest concentrations of IFN-gamma and TNF-alpha. On the 7th day post-infection, untreated and treated orchiectomized animals (IOR and IMOR) showed an enhanced number of peritoneal macrophages. Nitric oxide levels were also increased in untreated and treated orchiectomized (IOR and IMOR) when compared to the other groups, with or without LPS. Our data suggest that melatonin therapy associated with orchiectomy induced a stimulating effect on the immune response to the parasite. (c) 2012 Published by Elsevier Ltd.

Improvement of metabolic parameters and vascular function by metformin in obese non-diabetic rats

Aims: Metformin is an insulin sensitizing agent with beneficial effects in diabetic patients on glycemic levels and in the cardiovascular system. We examined whether the metabolic changes and the vascular dysfunction in monosodium glutamate-induced obese non-diabetic (MSG) rats might be improved by metformin. Main methods: 16 week-old MSG rats were treated with metformin for 15 days and compared with age-matched untreated MSG and non-obese non-diabetic rats (control). Blood pressure, insulin sensitivity, vascular reactivity and prostanoid release in the perfused mesenteric arteriolar bed as well as nitric oxide production and reactive oxygen species generation in isolated mesenteric arteries were analyzed. Key findings: 18-week-old MSG rats displayed higher Lee index, fat accumulation, dyslipidemia, insulin resistance and hyperinsulinemia. Metformin treatment improved these alterations. The norepinephrine-induced response, increased in the mesenteric arteriolar bed from MSG rats, was corrected by metformin. Indomethacin corrected the enhanced contractile response in MSG rats but did not affect metformin effects. The sensitivity to acetylcholine, reduced in MSG rats, was also corrected by metformin. Indomethacin corrected the reduced sensitivity to acetylcholine in MSG rats but did not affect metformin effects. The sensitivity to sodium nitroprusside was increased in preparations from metformin-treated rats. Metformin treatment restored both the reduced PGI2/TXA2 ratio and the increased reactive oxygen species generation in preparations from MSG rats. Significance: Metformin improved the vascular function in MSG rats through reduction in reactive oxygen species generation, modulation of membrane hyperpolarization. correction of the unbalanced prostanoids release and increase in the sensitivity of the smooth muscle to nitric oxide. (c) 2011 Elsevier Inc. All rights reserved.

Plasma corticosterone elevation inhibits the activation of nuclear factor kappa B (NFKB) in the Syrian hamster pineal gland

We evaluated how the mild stress-induced increase in endogenous corticosterone affected the pineal gland in Syrian hamsters (Mesocricetus auratus). The animals were maintained under constant light for 1 day, instead of a cycle of 14:10-h, to increase the circulating corticosterone levels during the daytime. The nuclear translocation of nuclear factor kappa B (NFKB), which is the pivotal transcription factor for stress and injury, presented a daily rhythm in normal animals. NFKB nuclear content increased linearly from the onset of light [Zeitgeber Time 0 (ZT0)] until ZT11 and decreased after ZT12 when the plasma corticosterone peak was detected in normal animals. However, the 24-h profiles of the two curves were different, and they did not clearly support an exclusive relationship between corticosterone levels and NFKB content. Therefore, we tested the effect of increased endogenous corticosterone through inducing mild stress by maintaining daytime illumination for one night. This stressful condition, which increased daytime corticosterone levels, resulted in a daytime decrease in NFKB nuclear content, and this was inhibited by mifepristone. Overall, this study shows that NFKB has a daily rhythm in Syrian hamster pineal glands and, by increasing endogenous corticosterone with a stressful condition, NFKB activity is regulated. Therefore, this study suggests that the pineal gland in the Syrian hamster is a sensor of stressful conditions.

Cerebral White Matter Oxidation and Nitrosylation in Young Rodents With Kaolin-Induced Hydrocephalus

Hydrocephalus is associated with reduced blood flow in periventricular white matter. To investigate hypoxic and oxidative damage in the brains of rats with hydrocephalus, kaolin was injected into the cisterna magna of newborn 7- and 21-day-old Sprague-Dawley rats, and ventricle size was assessed by magnetic resonance imaging at 7, 21, and 42 days of age. In-situ evidence of hypoxia in periventricular capillaries and glial cells was shown by pimonidazole hydrochloride binding. Biochemical assay of thiobarbituric acid reaction and immunohistochemical detection of malondialdehyde and 4-hydroxy-2-nonenal indicated the presence of lipid peroxidation in white matter. Biochemical assay of nitrite indicated increased nitric oxide production. Nitrotyrosine immunohistochemistry showed nitrosylated proteins in white matter reactive microglia and astrocytes. Activities of the antioxidant enzymes catalase and glutathione peroxidase were not increased, and altered hypoxia-inducible factor 1 alpha was not detected by quantitative reverse transcription-polymerase chain reaction. Cerebral vascular endothelial growth factor expression determined by quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay was not changed, but vascular endothelial growth factor immunoreactivity was increased in reactive astrocytes of hydrocephalic white matter. To determine if nitric oxide synthase is involved in the pathogenesis, we induced hydrocephalus in 7-day-old wild-type and neuronal nitric oxide synthase-deficient mice. At 7 days, the wild-type and mutant mice exhibited equally severe ventriculomegaly and no behavioral differences, although increased glial fibrillary acidic protein was less in the mutant mice. We conclude that hypoxia, via peroxidation and nitrosylation, contributes to brain changes in young rodents with hydrocephalus and that compensatory mechanisms are negligible.

5-Lipoxygenase Deficiency Impairs Innate and Adaptive Immune Responses during Fungal Infection

5-lipoxygenase-derived products have been implicated in both the inhibition and promotion of chronic infection. Here, we sought to investigate the roles of endogenous 5-lipoxygenase products and exogenous leukotrienes during Histoplasma capsulatum infection in vivo and in vitro. 5-LO deficiency led to increased lung CFU, decreased nitric oxide production and a deficient primary immune response during active fungal infection. Moreover, H. capsulatum-infected 5-LO-/- mice showed an intense influx of neutrophils and an impaired ability to generate and recruit effector T cells to the lung. The fungal susceptibility of 5-LO-/- mice correlated with a lower rate of macrophage ingestion of IgG-H. capsulatum relative to WT macrophages. Conversely, exogenous LTB4 and LTC4 restored macrophage phagocytosis in 5-LO deficient mice. Our results demonstrate that leukotrienes are required to control chronic fungal infection by amplifying both the innate and adaptive immune response during histoplasmosis.

Efficacia clinica dello stanozololo intrarticolare nella terapia dell'osteoartrosi di gomito nel cane

Il trattamento dell’osteoartrosi (OA) del cane è una sfida nella pratica clinica veterinaria. Molti trattamenti sono stati proposti, tuttavia la risposta clinica agli stessi non è sempre soddisfacente. Molti farmaci sono utilizzati per il trattamento dell’OA, tra cui farmaci anti-infiammatori non steroidei, corticosteroidi, ed inibitori della produzione dell’ossido nitrico. Lo stanozololo è un derivato sintetico del testosterone; oltre alle sue proprietà anaboliche/androgeniche , a basse dosi lo stanozololo ha un affinità per i recettori glucocorticoidi. Per questa attività antinfiammatoria e rigenerativa sui tessuti articolari danneggiati viene utilizzato nella degenerative joint desease del cavallo. Lo scopo di questo studio è stato di valutare l’efficacia clinica dello stanozololo intra-articolare a 15, 30, 45 e 60 giorni dal trattamento di gomiti con OA di cane. E’ stato eseguito uno studio cieco, multicentrico e randomizzato. Previo consenso informato, sono stati arruolati 48 cani, suddivisi in 3 gruppi e trattati con stanozololo, mavacoxib e con entrambi i farmaci. Sono state valutate zoppia, tollerabilità del trattamento, range of motion, e punteggio radiografico. Inoltre sono state stabilite e annoverate quantità e qualità del liquido sinoviale. Ai dati ottenuti sono stati applicati i test di Kruskal-Wallis, Chi-quadro e Fischer, i quali hanno dimostrato l’efficacia della terapia nei singoli gruppi e tra i diversi gruppi di studio. I risultati ottenuti hanno mostrato la riduzione di almeno un grado di zoppia e la riduzione della progressione dell’OA nei casi trattati con stanozololo. Si può quindi affermare che tale molecola per via intra-articolare può essere una valida alternativa per il trattamento dell’OA di gomito nel cane.

Endothelin inhibition improves cerebral blood flow and is neuroprotective in pneumococcal meningitis

By using an infant rat model of pneumococcal meningitis, we determined whether endothelins contribute to neuronal damage in this disease. Cerebrospinal fluid analysis demonstrated a significant increase of endothelin-1 in infected animals compared with uninfected controls. Histopathological examination 24 hours after infection showed brain damage in animals treated with ceftriaxone alone (median, 9.2% of cortex; range, 0-49.1%). In infected animals treated intraperitoneally with the endothelin antagonist bosentan (30 mg/kg, every 12 hours) also, injury was reduced to 0.5% (range, 0-8.6%) of cortex. Cerebral blood flow was reduced in infected animals (6.5 +/- 4.0 ml/min/100 g of brain vs 14.9 +/- 9.1 ml/min/100 g in controls. Treatment with bosentan restored cerebral blood flow to levels similar to controls (12.8 +/- 5.3 ml/min/100 g). Improved blood flow was not mediated by nitric oxide production, because bosentan had no effect on cerebrospinal fluid or plasma nitrite/nitrate concentrations at 6, 12, or 18 hours. These data indicate that endothelins contribute to neuronal injury in this model of pneumococcal meningitis by causing cerebral ischemia.