37 research outputs found

    Syzygium jambolanum treatment improves survival in lethal sepsis induced in mice

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    <p>Abstract</p> <p>Background</p> <p>The leaves and the fruits from <it>Syzygium jambolanum </it>DC.(Myrtaceae), a plant known in Brazil as sweet olive or 'jambolão', have been used by native people to treat infectious diseases, diabetes, and stomachache. Since the bactericidal activity of <it>S. jambolanum </it>has been confirmed <it>in vitro</it>, the aim of this work was to evaluate the effect of the prophylactic treatment with <it>S. jambolanum </it>on the <it>in vivo </it>polymicrobial infection induced by cecal ligation and puncture (CLP) in mice.</p> <p>Methods</p> <p>C57Bl/6 mice were treated by the subcutaneous route with a hydroalcoholic extract from fresh leaves of <it>S. jambolanum </it>(HCE). After 6 h, a bacterial infection was induced in the peritoneum using the lethal CLP model. The mice were killed 12 h after the CLP induction to evaluate the cellular influx and local and systemic inflammatory mediators' production. Some animals were maintained alive to evaluate the survival rate.</p> <p>Results</p> <p>The prophylactic HCE treatment increased the mice survival, the neutrophil migration to infectious site, the spreading ability and the hydrogen peroxide release, but decreased the serum TNF and nitrite. Despite the increased migration and activation of peritoneal cells the HCE treatment did not decrease the number of CFU. The HCE treatment induced a significant decrease on the bone marrow cells number but did not alter the cell number of the spleen and lymph node.</p> <p>Conclusion</p> <p>We conclude that the treatment with <it>S. jambolanum </it>has a potent prophylactic anti-septic effect that is not associated to a direct microbicidal effect but it is associated to a recruitment of activated neutrophils to the infectious site and to a diminished systemic inflammatory response.</p

    Early activation of p160(ROCK) by pressure overload in rat heart

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    We investigated the effects of acute pressure overload on activation of p160(ROCK) in rat myocardium. Constriction of transverse aorta, controlled to increase peak systolic pressure of ascending aorta by similar to40 mmHg, induced a rapid association of RhoA with Dbl-3 and p160(ROCK). The binding of p160(ROCK) to RhoA was rapidly increased, peaking at 30 min ( similar to 3.5- fold), but reduced to lower levels ( similar to 1.9- fold) by 60 min of pressure overload. The activity of immunoprecipitated p160(ROCK) toward myosin light chain increased similar to 2.5-fold within 10 min but decreased to lower levels ( similar to 1.6-fold) after 60 min of pressure overload. Confocal microscopic analysis indicated that pressure overload induced the formation of aggregates of p160(ROCK) and RhoA along the longitudinal axis of cardiac myocytes. Immunoelectron microscopic analysis showed that pressure overload induced the association of p160(ROCK) and RhoA to Z-line, T-tubule, and subsarcolemmal areas. The rapid activation of p160(ROCK) by pressure overload and its aggregation in subcellular structures involved in transmission of mechanical force suggest a role for this enzyme in the mechanobiochemical transduction in the myocardium.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.2846C1411C141

    Early Activation Of P160rock By Pressure Overload In Rat Heart

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    We investigated the effects of acute pressure overload on activation of p160ROCK in rat myocardium. Constriction of transverse aorta, controlled to increase peak systolic pressure of ascending aorta by -40 mmHg, induced a rapid association of RhoA with Dbl-3 and p160ROCK. The binding of p160ROCK to RhoA was rapidly increased, peaking at 30 min (∼3.5-fold), but reduced to lower levels (∼1.9-fold) by 60 min of pressure overload. The activity of immunoprecipitated p160ROCK toward myosin light chain increased ∼2.5-fold within 10 min but decreased to lower levels (∼1.6-fold) after 60 min of pressure overload. Confocal microscopic analysis indicated that pressure overload induced the formation of aggregates of p160ROCK and RhoA along the longitudinal axis of cardiac myocytes. Immunoelectron microscopic analysis showed that pressure overload induced the association of p160ROCK and RhoA to Z-line, T-tubule, and subsarcolemmal areas. 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    MEF2C DNA-binding activity is inhibited through its interaction with the regulatory protein Ki-1/57

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    Myocyte enhancer factor (MEF2) are MADS box transcription fa:tors that play important roles in the regulation of myogenesis and morphogenesis of muscle cells. MEF2 proteins are activated by mechanical overload in the heart. In this study, we found the interaction of MEF2C with the regulatory protein Ki-1/57 using yeast two-hybrid system. This interaction was confirmed by GST-pull down assay in vitro and by co-immunoprecipitation in vivo. This interaction is also dependent on pressure overload in the heart. Co-imunoprecipitation assay with anti-MEF2 and anti-Ki-1/57 antibodies demonstrated a basal association between these proteins in the left ventricles of control rats. Pressure overload caused a reduction in this association. Ki-1/57 co-localizes with MEF2 in the nucleus of myocytes of control rats. However, after submitting the animals to pressure overload Ki-1/57 leaves the nucleus thereby decreasing this co-localization. Ki-1/57 also exerts an inhibitory effect upon MEF2C DNA binding activity. These results suggest that Ki-1/57 is a new interacting partner of MEF2 protein and may be involved in the regulation of MEF2 at the onset of hypertrophy. &COPY; 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.579122615262

    Both Interleukin-3 and Interleukin-6 Are Necessary for Better Ex Vivo Expansion of CD133+Cells From Umbilical Cord Blood

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Umbilical cord blood (UCB), an ideal source for transplantable hematopoietic stem cells (HSC), is readily available and is rich in progenitor cells. Identification of conditions favoring UCB-HSC ex vivo expansion and of repopulating potential remains a major challenge in hematology. CD133+ cells constitute an earlier, less-differentiated HSC group with a potentially higher engraftment capacity. The presence of SCF, Flt3-L, and TPO are essential for CD133+ and/or CD34+ cells ex vivo expansion; however, IL-3 and IL-6 influence has not yet been clearly established. We investigated this influence on CD133+ cells from UCB ex vivo expansion and the effect of these cytokines upon cell phenotype. Immediately after isolation an 85% of CD133+ cell purity was obtained, diminishing after 4 and 8 days of ex vivo expansion. CD133+ fold-increase was higher using IMDM with SCF, Flt3-L, and TPO (BM)+IL-3 or BM+IL-3+IL-6 on day 8 (13.83- and 17.47-fold increase, respectively). BM+IL-6 presented no significant difference from BM alone. We demonstrated that 5.1% of the CD133+ cells expressed IL-6 receptor (IL-6R) after isolation. After 4 and 8 days in culture, the percentage of CD133+ cells that expressed IL-6R was as follows: BM alone (9.8% and 22.02%, respectively); BM+IL-3 (8.33% and 16.74%); BM+IL-6 (9.2% and 17.67%); and BM+IL-3+IL-6 (12.5% and 61.20%). Cell cycle analysis revealed quiescent cells after isolation, 95.5% CD133+ cells in the G0/G1 phase. Regardless of culture period or cytokine incubation, CD133+ cell cycle altered to 70% of CD133+ in the G0/G1 phase. Colony-forming unit (CFU) doubled in BM+IL-3+IL-6 after 8 days of incubation compared with BM group. SOX-2 and NANOG-relative gene expression was detected on day 0 after isolation. BM+IL-6 prevented the decrease in NANOG and SOX-2 gene expression level compared to BM+IL-3 or BM+IL-3+IL-6 incubated cells. Our results indicated that UCB-isolated CD133+ cells were better ex vivo expanded in the presence of SCF, Flt3-L, TPO, IL-3+IL-6. IL-3 probably promotes higher CD133+ cell expansion and IL-6 maintains immature phenotype.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.193413421Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Fak Signalling Mediates Nf-kappab Activation By Mechanical Stress In Cardiac Myocytes.

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    Nuclear Factor (NF)-kappaB and Focal Adhesion Kinase (FAK) signalling are implicated in cardiomyocyte hypertrophy. We investigated whether FAK signalling contributed towards NF-kappaB activation by mechanical stress in cardiac myocytes. Experiments were performed with pressure overload rat left ventricle and isolated cardiac myocytes from adult rats and isolated neonatal rat ventricular myocytes (NRVMs) underwent in vitro stretching. Pressure overload induced NF-kappaB increase in myocardial cell nuclear extracts. Adult rat isolated cardiac myocyte confocal microscopy analysis showed NF-kappaB detected into nuclei. Cyclic stretch increased the amount and NF-kappaB DNA-binding activity in NRVMs nuclear extracts. NRVMs confocal microscopy confirmed NF-kappaB subcellular relocation in stretched cells. Changes in NF-kappaB subcellular location and DNA-binding activity in stretched NRVMs were paralleled by increased FAK phosphorylation, detected in stretched NRVMs by anti-phosphospecific antibody directed to Tyr397. NRVMs treatment with FAK/Src pharmacological inhibitor attenuated NF-kappaB subcelullar relocation and increased DNA binding activity induced by cyclic stretch in cardiac myocytes. FAK signalling coordinates cardiac myocyte NF-kappaB activation in response to mechanical stress. Further studies are needed to elucidate the influence of this signalling pathway on gene transcription regulation, and cardiac myocyte phenotypic changes in response to mechanical stress.40381-

    Radiofrequency catheter ablation of concealed accessory pathways in two dogs with symptomatic atrioventricular reciprocating tachycardia

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    Radiofrequency catheter ablation (RFCA) is widely used as a curative therapeutic strategy in human beings with paroxysmal supraventricular tachycardia (SVT), but rarely applied in animals. This report describes successful RFCA of atrioventricular accessory pathways (AP) in two dogs with episodic weakness caused by frequent paroxysms of supraventricular tachycardia. METHODS AND RESULTS: Invasive electrophysiological studies (EPS) identified two APs in the 1st dog (right postero-septal, right posterior), and one in the 2nd dog (right posterior). Programmed electrical stimulation demonstrated that all APs had only retrograde unidirectional conduction, and played a role to maintain inducible atrioventricular reciprocating tachycardia (AVRT). The bypass tracts were successfully eliminated with RFCA, with consequent prevention of AVRT induction during post-ablation EPS. At 8months follow-up, the dogs were asymptomatic, and no reoccurrence of tachycardia was seen. CONCLUSION: Concealed APs responsible for AVRT and accompanied symptoms may be safely eliminated using RFCA in dog
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