RESUMO
BACKGROUND: Sepsis is an emergency medical condition that can lead to death and it is defined as a life-threatening organ dysfunction caused by immune dysregulation in response to an infection. It is considered the main killer in intensive care units. Sepsis associated-encephalopathy (SAE) is mostly caused by a sepsis-induced systemic inflammatory response. Studies report SAE in 14-63% of septic patients. Main SAE symptoms are not specific and usually include acute impairment of consciousness, delirium and/or coma, along with electroencephalogram (EEG) changes. For those who recover from sepsis and SAE, impaired cognitive function, mobility and quality of life are often observed months to years after hospital discharge, and there is no treatment available today to prevent that. Inflammation and oxidative stress are key players for the SAE pathophysiology. Gold nanoparticles have been demonstrated to own important anti-inflammatory properties. It was also reported 20 nm citrate-covered gold nanoparticles (cit-AuNP) reduce oxidative stress. In this context, we tested whether 20 nm cit-AuNP could alleviate the acute changes caused by sepsis in brain of mice, with focus on inflammation. Sepsis was induced in female C57BL/6 mice by cecal ligation and puncture (CLP), 20 nm cit-AuNP or saline were intravenously (IV) injected 2 h after induction of sepsis and experiments performed 6 h after induction. Intravital microscopy was used for leukocyte and platelet adhesion study in brain, blood brain barrier (BBB) permeability carried out by Evans blue assay, cytokines measured by ELISA and real time PCR, cell adhesion molecules (CAMs) by flow cytometry and immunohistochemistry, and transcription factors, by western blotting. RESULTS: 20 nm cit-AuNP treatment reduced leukocyte and platelet adhesion to cerebral blood vessels, prevented BBB failure, reduced TNF- concentration in brain, and ICAM-1 expression both in circulating polymorphonuclear (PMN) leukocytes and cerebral blood vessels of mice with sepsis. Furthermore, 20 nm cit-AuNP did not interfere with the antibiotic effect on the survival rate of mice with sepsis. CONCLUSIONS: Cit-AuNP showed important anti-inflammatory properties in the brain of mice with sepsis, being a potential candidate to be used as adjuvant drug along with antibiotics in the treatment of sepsis to avoid SAE.
Assuntos
Ceco/metabolismo , Ouro/farmacologia , Inflamação/tratamento farmacológico , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Microvasos/metabolismo , Sepse/tratamento farmacológico , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Encefalopatias , Adesão Celular , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Inflamação/patologia , Leucócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microvasos/patologia , Neutrófilos/metabolismo , Qualidade de Vida , Sepse/metabolismo , Sepse/patologia , Encefalopatia Associada a Sepse/metabolismoRESUMO
CdFe2O4 nanoparticles of around 3.9 nm were synthesized using the coprecipitation method and protected by a silica layer. The nanoparticles were mixed with a coacervate and transformed into phosphate glasses with 1, 4 and 8% in mass of nanoparticles by the melt-quenching method. TEM images confirm that the nanoparticles were successfully incorporated into the matrix without inducing crystallization. 31P NMR and Raman spectral analyses show that new P-O-Si bonds are formed in the glasses containing nanoparticles. The glass transition increases as a function of the nanoparticle content due to an increase in the connectivity of the phosphate glass chains. The UV-Vis spectra show bands at 415 and 520 nm assigned to Fe3+ ions and at 1025 nm, characteristic of Fe2+ ions, indicating that some of the nanoparticles dissolve during the melting process. The sample with 8% CdFe2O4 presents a paramagnetic behavior. The glasses obtained are transparent, non-hygroscopic and possess enormous thermal stability which is important for the production of optical devices.
RESUMO
The production of virulence attributes in three reference strains and 11 clinical isolates primarily identified as Candida parapsilosis was evaluated. Morphological and phenotypical tests were not able to discriminate among the three species of the C. parapsilosis complex; consequently, molecular methods were applied to solve this task. After employing polymerase chain reaction-based methods, nine clinical strains were identified as C. parapsilosis sensu stricto and two as C. orthopsilosis. Protease, catalase, and hemolysin were produced by all 14 strains, while 92.9% and 78.6% of strains secreted, respectively, esterase and phytase. No phospholipase producers were detected. Mannose/glucose, N-acetylglucosamine, and sialic acid residues were detected at the surface of all strains, respectively, in high, medium, and low levels. All strains presented elevated surface hydrophobicity and similar ability to form biofilm. However, the adhesion to inert substrates and mammalian cells was extremely diverse, showing typical intrastrain variations. Overall, the strains showed (1) predilection to adhere to plastic over glass and the number of pseudohyphae was more prominent than yeasts and (2) the interaction process was slightly enhanced in macrophages than fibroblasts, with the majority of fungal cells detected inside them. Positive/negative correlations were demonstrated among the production of these virulence traits in C. parapsilosis complex.
Assuntos
Candida/classificação , Fenótipo , Biofilmes , Candida/fisiologia , Candida/ultraestrutura , Membrana Celular/química , Membrana Celular/metabolismo , Glicosilação , Humanos , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Tipagem Molecular , Filogenia , RNA Fúngico , RNA Ribossômico 28S , Virulência/genéticaRESUMO
Blackheart is a physiological disorder induced by postharvest chilling storage during pineapple fruit export shipping. The aim of this study was to check the involvement of bromelain, the cysteine protease protein family abundantly present in pineapple fruits, and AcCYS1, an endogenous inhibitor of bromelain, in the development of blackheart. For this we checked the response to postharvest chilling treatment of two pineapple varieties (MD2 and Smooth Cayenne) differing in their resistance to blackheart. Quantitative RT-PCR analyses showed that postharvest chilling treatment induced a down-regulation of bromelain transcript accumulation in both varieties with the most dramatic drop in the resistant variety. Regarding AcCYS1 transcript accumulation, the varieties showed opposite trends with an up-regulation in the case of the resistant variety and a down-regulation in the susceptible one. Taken together our results suggest that the control of bromelain and AcCYS1 expression levels directly correlates to the resistance to blackheart development in pineapple fruits.
Assuntos
Ananas/fisiologia , Bromelaínas/genética , Cistatinas/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Ananas/genética , Bromelaínas/metabolismo , Temperatura Baixa , Cistatinas/metabolismo , Frutas/genética , Frutas/fisiologia , Dados de Sequência Molecular , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Relaxing action of sodium nitroprusside (SNP) was significantly reduced in the stomach fundus of mice lacking the kinin B(1) receptor (B(1)(-/-)). Increased basal cGMP accumulation was correlated with attenuated SNP induced dose-dependent relaxation in B(1)(-/-) when compared with wild type (WT) control mice. These responses to SNP were completely blocked by the guanylate cyclase inhibitor ODQ (10 microM). It was also found that Ca(2+)-dependent, constitutive nitric oxide synthase (cNOS) activity was unchanged but the Ca(2+)-independent inducible NOS (iNOS) activity was greater in B(1)(-/-) mice than in WT animals. Zaprinast (100 microM), a specific phosphodiesterase inhibitor, increased the nitrergic relaxations and the accumulation of the basal as well as the SNP-stimulated cGMP in WT but not in B(1)(-/-) stomach fundus. From these findings it is concluded that the inhibited phosphodiesterase activity and high level of cGMP reduced the resting muscle tone, impairing the relaxant responses of the stomach in B(1)(-/-) mice. In addition, it can be suggested that functional B(2) receptor might be involved in the NO compensatory mechanism associated with the deficiency of kinin B(1) receptor in the gastric tissue of the transgenic mice.
Assuntos
Receptor B1 da Bradicinina/genética , Estômago/fisiologia , Animais , GMP Cíclico/metabolismo , Mucosa Gástrica/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Músculo Liso/efeitos dos fármacos , Músculo Liso/enzimologia , Músculo Liso/metabolismo , Músculo Liso/fisiologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/metabolismo , Nitroprussiato/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Purinonas/farmacologia , Estômago/efeitos dos fármacos , Estômago/enzimologiaRESUMO
Abnormalities in vascular function are well recognized in diabetes. Hyperglycemia may be central to the pathogenesis of vascular dysfunction but is not certain whether improvements in glycaemic control will improve vascular function. The effects of metformin, an antidiabetic agent that improves insulin sensitivity and glycaemic control, on the microvascular reactivity have not been reported in neonatal streptozotocin-induced (n-STZ) diabetes. Diabetes was induced by STZ injection (160 mg/kg, ip) in neonates (2-day-old) Wistar rats. n-STZ diabetic rats were treated with metformin (300 mg/kg, 15 d, by gavage). Using intravital microscopy the changes in mesenteric arteriolar and venular diameters were determined in anesthetized control and n-STZ diabetic rats, before and after topical application of endothelium-dependent vasodilator agents, mediators or not of the inflammatory response, and endothelium-independent vasodilator agent. We also determined the total nitric oxide synthase (NOS) activity (conversion of L-arginine to citrulline) and endothelial(e), inducible(i), and neuronal(n) NOS expression (using polymerase chain reaction after reverse transcription of the mRNAs into cDNAs) in the mesentery of metformin-treated n-STZ diabetic and vehicle-treated n-STZ diabetic and control rats. Although metformin treatment did not correct the high glycaemic levels and the impaired glucose tolerance, the reduced vasodilator responses and total NOS activity in n-STZ diabetic rats were corrected by the treatment. Neither diabetes nor metformin treatment altered the expression of the three NOS isoforms. We concluded that metformin restores the reduced response to vasodilator agents, independently of the correction of the metabolic alterations. Improvement of total NOS activity might be in part responsible for the correction.
Assuntos
Animais Recém-Nascidos/fisiologia , Diabetes Mellitus Experimental/fisiopatologia , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Capilares/efeitos dos fármacos , Capilares/enzimologia , Capilares/fisiologia , Diabetes Mellitus Experimental/enzimologia , Ingestão de Alimentos , Teste de Tolerância a Glucose , Hiperglicemia/fisiopatologia , Masculino , Óxido Nítrico Sintase Tipo III , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Circulação Esplâncnica/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
A determinaçäo dos fenótipos Rh, Kell, Duffy e Kidd, associada ao ABO é utilizada para prevenir a aloimunizaçäo a antígenos eritrocitários e participam também no processo de identificaçäo de anticorpos nos pacientes com B talassemia. Todavia, a fenotipagem desses pacientes é trabalhosa e de difícil interpretaçäo. Nesta situaçäo, deve ser avaliada uma alternativa ao teste de hemaglutinaçäo para determinar o padräo antigênico dos pacientes. Utilizamos para tal fim o método PCR-RFLP. Foram preparados DNAs de 50 pacientes com Btalassemia que haviam sido anteriormente fenotipados pela hamglutinaçäo e testados para Kell, Kidd, Duffy/GATA mutaçäo por PCR-RFLP. RHD/näo-D foi analisado pelo tamanho do produto, do PCR associado à seqüência do gene RHD no intron 4 e exon 10/3' UTR. Os testes de genotipagem foram realizados sem o conhecimento dos resultados dos fenótipos. Para os RHD/näo-D, 47 foram RHD+ e RHD+/RHCE+, e 3 foram RHD- e RHD-/RHCE+. Para o Kell, 48 kk foram K2K2 e 2 Kk foram K1K2. Para o Duffy, das 44 amostras que haviam sido normais, GATA box, 8 Fy(a+b-)foram FYA/FYA, 15Fy(a+b-) foram FYB/FYB; e 19 Fy(a+b+) foram FYA/FYB; das outras 4 amostras, 3 foram FYA/FYB; homozigoto GATA mutaçäo. Duas amostras fenotipadas como Fy(a+b-), que eram normais GATA, apresentavam as mutaçöes 265T/298a e 2 amostras fenotipadas como Fy(a+b+) haviam sido genotipadas como FYA/FYB. Para o Kidd, 15Jk(a+b+) foram JKA/JKA, 12jk(aa-b+) foram JKB/JKB, e 20 jk(a+b+) haviam sido genotipadas como JKB/JKB. A genotipagem é mais acurada que a fenotipagem para determinaçäo de grupos sangüíneos em pacientes portadores de B talassemia poli transfundidos. A genotipagem nesses pacientes pode ser importante para selecionar hemácias antigenicamente negativas para transfusäo de glóbulos vermelhos.