RESUMO
The Hansen et al critique centers on the lack of spatial agreement between two very different datasets. Nonetheless, properly constructed comparisons designed to reconcile the two datasets yield up to 90% agreement (e.g., in South America).
Assuntos
Carbono/análise , Clima Tropical , Biomassa , Florestas , América do SulRESUMO
We described the clinical evolution of patients with structural heart disease presenting at the emergency room with syncope. Patients were stratified according to their syncope etiology and available scores for syncope prognostication. Cox proportional hazard models were used to investigate the relationship between etiology of the syncope and event-free survival. Of the 82,678 emergency visits during the study period, 160 (0.16%) patients were there due to syncope, having a previous diagnosis of structural heart disease. During the median follow-up of 33.8±13.8 months, mean age at the qualifying syncope event was 68.3 years and 40.6% of patients were male. Syncope was vasovagal in 32%, cardiogenic in 57%, orthostatic hypotension in 6%, and of unknown causes in 5% of patients. The primary composite endpoint death, readmission, and emergency visit in 30 days was 39.4% in vasovagal syncope and 60.6% cardiogenic syncope (P<0.001). Primary endpoint-free survival was lower for patients with cardiogenic syncope (HR=2.97, 95%CI=1.94-4.55; P<0.001). The scores were analyzed for diagnostic performance with area under the curve (AUC) and did not help differentiate patients with an increased risk of adverse events. The differential diagnosis of syncope causes in patients with structural heart disease is important, because vasovagal and postural hypotension have better survival and less probability of emergency room or hospital readmission. The available scores are not reliable tools for prognosis in this specific patient population.
Assuntos
Cardiomiopatias/complicações , Serviços Médicos de Emergência/estatística & dados numéricos , Síncope/etiologia , Idoso , Brasil/epidemiologia , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Cardiopatias/complicações , Cardiopatias/epidemiologia , Humanos , Masculino , Modelos de Riscos Proporcionais , Fatores de Risco , Análise de Sobrevida , Síncope/mortalidadeRESUMO
Organophosphorus compounds (OP) represent a class of insecticides that are used most globally. The neurotoxic effects are attributed mainly to acetylcholinesterase (AChE) enzyme inhibition, which is responsible for cholinergic manifestations in individuals acutely exposed to OP. However, AChE inhibition alone cannot account for the wide range of symptoms that were reported following OP exposures. In agreement with this, evidence shows that non-cholinergic events may be mechanistically linked to OP-induced neurotoxicity. The aim of this study was to investigate the potential occurrence of oxidative stress as a critical step in the toxicity induced by the OP malaoxon(MAL) using primary cultures of mouse cortical neurons, as well as to distinguish MAL-induced oxidative stress and cell toxicity from an action on AChE blockade. Primary cultures of mouse cortical neurons were treated with MAL (0.01; 0.1; 1; 10; or 100 µM) at varying time points (1, 3, 6, 24, 48, or 144 hr) and the following biochemical parameters determined including cell viability, AChE activity, and superoxide production. MAL significantly reduced cell viability in a concentration- and time-dependent manner. Of note, 1 µM MAL significantly inhibited (approximately 75%) AChE activity after 48 hr incubation. Pralidoxime (PRAL) (600 µM), a classical AChE reactivator, significantly protected against MAL-induced AChE blockade; however, PRAL did not affect MAL-mediated fall in cellular viability, indicating that AChE inhibition is not necessarily correlated with insecticide-induced decrease in cell survival. MAL-induced diminished cell viability was preceded by a significant increase in superoxide anion production. The antioxidant agent ascorbic acid (AA) (200 µM), which significantly protected against MAL-induced superoxide anion production, did not alter MAL-induced AChE inhibition and significantly prevented insecticide-mediated fall in cell survival. Data show that increased superoxide anion production is an event that precedes MAL-induced cell toxicity in primary cultures of mouse cortical neurons. Based on the preventative effects of AA against MAL-mediated superoxide anion production and reduced cell viability, evidence indicates that oxidative stress represents an important step mediating MAL-induced toxicity in neurons and that AChE inhibition is not necessarily correlated with lowered cell survival noted in insecticide-exposed cells.
Assuntos
Inseticidas/toxicidade , Malation/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Superóxidos/metabolismo , Acetilcolinesterase/metabolismo , Animais , Células Cultivadas , Malation/toxicidade , Camundongos , Neurônios/efeitos dos fármacosRESUMO
Follicular atresia in granulosa and theca cells occurs by apoptosis through weak hormonal stimulation. We have previously proposed an in vitro model to study this process by inducing apoptosis in BGC-1, a bovine granulosa cell line, and in primary cultures from ovaries with or without corpus luteum (CPGB+ and CPGB-, respectively), with different doses of gonadotropin releasing hormone (GnRH) analogs (leuprolide acetate (LA) as agonist and antide as antagonist). BGC-1 represent immature granulosa cells, whereas CPGB represent different degrees of luteinization. Our aim was to evaluate the intracellular pathways involved in the GnRH regulation of apoptosis in BGC-1. Treatment with LA 100nM but not with antide led to an increase in BAX over BCL-2 expression, showing antagonism of antide. All treatments inhibited phospholipase-D (PLD) activity compared to control, implying agonist behavior of antide. Progesterone in vitro production and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) expression revealed different degrees of luteinization: BGC-1 were immature, whereas CPGB+ were less differentiated than CPGB-. We concluded that LA-induced apoptosis in BGC-1 occurs by activation of the mitochondrial pathway and by inhibition of PLD activity and that antide might work both as an antagonist of the intrinsic pathway and as an agonist of the extrinsic protection pathway by inhibiting PLD activity.
Assuntos
Apoptose/fisiologia , Diferenciação Celular/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Células da Granulosa/citologia , Animais , Apoptose/efeitos dos fármacos , Bovinos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Genes bcl-2/genética , Hormônio Liberador de Gonadotropina/análogos & derivados , Células da Granulosa/efeitos dos fármacos , Leuprolida/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Oligopeptídeos/farmacologia , Ovário/citologia , Ovário/metabolismo , Fosfolipase D/metabolismo , Transdução de Sinais , Proteína X Associada a bcl-2/genéticaRESUMO
During pregnancy, apoptosis is a physiological event critical in the remodeling and aging of the placenta. Increasing evidence has pointed towards the relevance of endocannabinoids (ECs) and hypoxia as modulators of trophoblast cell death. However, the relation between these factors is still unknown. In this report, we evaluated the participation of ECs in placental apoptosis induced by cobalt chloride (CoCl2), a hypoxia mimicking agent that stabilizes the expression of hypoxia inducible factor-1 alpha (HIF-1α). We found that HIF-1α stabilization decreased FAAH mRNA and protein levels, suggesting an increase in ECs tone. Additionally, CoCl2 incubation and Met-AEA treatment reduced cell viability and increased TUNEL-positive staining in syncytiotrophoblast layer. Immunohistochemical analysis demonstrated Bax and Bcl-2 protein expression in the cytoplasm of syncytiotrophoblast. Finally, HIF-1α stabilization produced an increase in Bax/Bcl-2 ratio, activation of caspase 3 and PARP cleavage. All these changes in apoptotic parameters were reversed with AM251, a CB1 antagonist. These results demonstrate that HIF-1α may induce apoptosis in human placenta via intrinsic pathway by a mechanism that involves activation of CB1 receptor suggesting a role of the ECs in this process.
Assuntos
Apoptose , Endocanabinoides/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Placenta/citologia , Apoptose/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular , Cobalto/farmacologia , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Placenta/efeitos dos fármacos , Placenta/metabolismo , Gravidez , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Dentistry and orthopedics are undergoing a revolution in order to provide more reliable, comfortable and long-lasting implants to patients. Titanium (Ti) and titanium alloys have been used in dental implants and total hip arthroplasty due to their excellent biocompatibility. However, Ti-based implants in human body suffer surface degradation (corrosion and wear) resulting in the release of metallic ions and solid wear debris (mainly titanium dioxide) leading to peri-implant inflammatory reactions. Unfortunately, our current understanding of the biological interactions with titanium dioxide nanoparticles is still very limited. Taking this into consideration, this study focuses on the internalization of titanium dioxide nanoparticles on primary bone cells, exploring the events occurring at the nano-bio interface. For the first time, we report the selective binding of calcium (Ca), phosphorous (P) and proteins from cell culture medium to anatase nanoparticles that are extremely important for nanoparticle internalization and bone cells survival. In the intricate biological environment, anatase nanoparticles form bio-complexes (mixture of proteins and ions) which act as a kind of 'Trojan-horse' internalization by cells. Furthermore, anatase nanoparticles-induced modifications on cell behavior (viability and internalization) could be understand in detail. The results presented in this report can inspire new strategies for the use of titanium dioxide nanoparticles in several regeneration therapies.
Assuntos
Endocitose , Nanopartículas Metálicas/química , Osteoblastos/metabolismo , Titânio/metabolismo , Cálcio/metabolismo , Sobrevivência Celular , Células Cultivadas , Citoplasma/metabolismo , Citoplasma/ultraestrutura , Humanos , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica , Osteoblastos/citologia , Osteoblastos/ultraestrutura , Tamanho da Partícula , Fósforo/metabolismo , Ligação Proteica , Titânio/química , Difração de Raios XRESUMO
Yerba-mate (Ilex paraguariensis St. Hil.) is the most used beverage in Latin America with approximately 426 thousand of tons consumed per year. Considering the broad use of this plant, we aimed to investigate the anxiety-like and stimulant activity of both the hydroethanolic (HE) and aqueous (AE) extracts from leaves of I. paraguariensis. Swiss mice were treated with I. paraguariensis HE or AE chronically or acutely, respectively, followed by evaluation in the elevated plus-maze (EPM; anxiety-like paradigm), open field (OF; locomotor activity) or the step-down avoidance task (memory assessment). Following behavioral protocols the brains were collected for evaluation of acetylcholinesterase (AChE) activity ex vivo. Chronic treatment with HE induced an anxiolytic-like effect and increased motor activity besides augmented AChE activity. Additionally, acute treatment with AE prevented the scopolamine-induced memory deficit in the step-down avoidance task. Overall, our results indicate the importance of the I. paraguariensis-induced CNS effects, since it is a widely used nutraceutical. We have reported anxiolytic, stimulant and neuroprotective effects for this plant species. These effects are potentially modulated by the cholinergic system as well as by caffeine.
Assuntos
Ansiolíticos/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Ilex paraguariensis , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta , Acetilcolinesterase/metabolismo , Animais , Ansiolíticos/química , Ansiedade/tratamento farmacológico , Aprendizagem da Esquiva/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Cafeína/química , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/química , Colinérgicos/química , Colinérgicos/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Ilex paraguariensis/química , Masculino , Transtornos da Memória/prevenção & controle , Camundongos , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/química , Fototerapia , Extratos Vegetais/química , Folhas de Planta/química , EscopolaminaRESUMO
The peritoneum is a thin membrane that covers most of the abdominal organs, composed of a monolayer of mesothelial cells and subjacent submesothelial loose connective tissue. Cells from the peritoneal wall are correlated with peritoneal fibrosis and epithelial-to-mesenchymal transition. However, the distinct involvement of mesothelial or submesothelial cells in such phenomena is still not clear. Here, we propose a new strategy to obtain stromal cells from anterior peritoneal wall explant cultures. These cells migrated from peritoneal tissues and proliferated in vitro for 4 weeks as adherent fibroblast-like cells. Optical and electronic microscopy analyses of the fragments revealed a significant submesothelial disorganization. The obtained cells were characterized as cytokeratin- vimentin+ laminin+ α-smooth muscle actin+, suggesting a connective tissue origin. Moreover, at the third passage, these stromal cells were CD90+CD73+CD29+Flk-1+CD45-, a phenotype normally attributed to cells of mesenchymal origin. These cells were able to support hematopoiesis, expressing genes involved in myelopoiesis (SCF, G-CSF, GM-CSF, IL-7 and CXCL-12), and differentiated into osteogenic and adipogenic cell lineages. The methodology demonstrated in this work can be considered an excellent experimental model to understand the physiology of the peritoneal wall in healthy and pathological processes. Moreover, this work shows for the first time that submesothelial stromal cells have properties similar to those of mesenchymal cells from other origins.
Assuntos
Adipogenia , Linhagem da Célula , Epitélio/metabolismo , Hematopoese , Osteogênese , Peritônio/citologia , Animais , Movimento Celular , Separação Celular , Técnicas de Cocultura , Citometria de Fluxo , Cinética , Masculino , Camundongos Endogâmicos BALB C , Mielopoese , Peritônio/ultraestrutura , Fenótipo , Células Estromais/citologia , Células Estromais/metabolismoRESUMO
UNLABELLED: Placental hypoxia has been implicated in pregnancy pathologies such as preeclampsia. We have previously reported that AQP9 is highly expressed in syncytiotrophoblast from normal placentas and shows an overexpression in preeclamptic placentas, with a lack of functionality for water transport. Up to now, the response of AQP9 to changes in the oxygen tension in trophoblast cells is still unknown. OBJECTIVE: Our aim was to establish whether alterations in oxygen levels may modulate AQP9 expression in human placenta. METHODS: A theoretical analysis of the human AQP9 gene to find conserved DNA regions that could serve as putative HIF-1 binding sites. Then, explants from normal placentas were cultured at different concentrations of oxygen or with 250 µM CoCl2. AQP9 molecular expression and water uptake was determined. RESULTS: Fourteen consensus HIF-1 binding sites were found in the human AQP9 gene, but none of them in the promoter region. However, placental AQP9 decreased abruptly when HIF-1α is expressed by deprivation of oxygen or CoCl2 stabilization. In contrast, after reoxygenation, HIF-1α was undetectable while AQP9 increased significantly and changed its cellular distribution, showing the same pattern as that previously described in preeclamptic placentas. Accordingly with the decrease in AQP9 expression, water uptake decreased in explants exposed to hypoxia or treated with CoCl2. Conversely as we expected, after reoxygenation, water uptake decreased dramatically compared to the control and was not sensitive to HgCl2. CONCLUSION: Our findings suggest that oxygen tension may modulate AQP9 expression in human placenta. However, the role of AQP9 still remains uncertain.
Assuntos
Aquaporinas/biossíntese , Hipóxia/metabolismo , Oxigênio/administração & dosagem , Placenta/metabolismo , Feminino , Humanos , Pressão Parcial , GravidezRESUMO
Anandamide (AEA) is a lipid mediator that participates in the regulation of several reproductive functions. This study investigated the endocannabinoid system in normal (NP) and preeclamptic (PE) placentas, and analyzed the potential functional role of AEA in the regulation of nitric oxide synthesis. The protein expression and localization of NAPE-PLD, FAAH and CB1 receptor were analyzed in normal and preeclamptic pregnancies using immunoblotting and immunohistochemistry. NAPE-PLD expression was shown to be significantly higher (p < 0.05) in PE tissues than in NP. In contrast, a decrease in FAAH protein (p < 0.001) was detected in placentas collected from women with preeclampsia. Both enzymes were mainly located in the syncytiotrophoblasts from normal and preeclamptic tissues. No differences were seen in CB1 receptor from both groups of placental villous. Exogenous and endogenous AEA significantly increased NOS activity. Although pre-incubation with AM251 (CB1 antagonist) had no effect, co-incubation with both AEA and AM251 diminished NOS activity from normal term placentas. We observed increased NOS activity in placental villous from women with preeclampsia compared with normotensive pregnant women. Furthermore, NOS activity from preeclamptic tissues was diminished by co-treatment with AM251, illustrating that the NO levels could be modulated by AEA. These data suggest that AEA may be one of the factors involved in the regulation of NOS activity in normal and preeclamptic placental villous. Interestingly, the differential expression of NAPE-PLD and FAAH suggests that AEA could play an important role in the pathophysiology of PE.