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BACKGROUND: Maternal overweight and obesity have been associated with an increased risk of atopic dermatitis (AD) in the offspring, but the underlying mechanisms are unclear. Vernix caseosa (VC) is a proteolipid material covering the fetus produced during skin development. However, whether maternal prepregnancy weight excess influences fetal skin development is unknown. Characterizing the VC of newborns from mothers with prepregnancy overweight and obesity might reveal AD-prone alterations during fetal skin development. OBJECTIVE: We sought to explore AD biomarkers and staphylococcal loads in VC from the offspring of mothers who were overweight/obese (O/O) before pregnancy versus in those from offspring of normal weight mothers. METHODS: The VC of newborns of 14 O/O and 12 normal weight mothers were collected immediately after birth. Biomarkers were determined by ELISA and staphylococcal species by quantitative PCR. RESULTS: The VC from the O/O group showed decreased expression of skin barrier proteins (filaggrin and loricrin) and increased levels of proinflammatory biomarkers (IgA, thymic stromal lymphopoietin [TSLP], S100A8, IL-25, and IL-33). No differences in concentrations of antimicrobial peptides and enzymes were detected. The VC from the O/O group had a lower Staphylococcus epidermidis and Staphylococcus hominis commensal bacterial load, whereas Staphylococcus aureus bacterial load was not significantly different between the 2 groups. Maternal body mass index was negatively correlated with VC filaggrin expression and S epidermidis load and was positively associated with TSLP concentration. One-year follow-up established that the offspring of O/O mothers had a higher incidence of AD that was specifically linked with decreased VC filaggrin expression and lower S epidermidis load. CONCLUSIONS: VC from neonates of mothers with prepregnancy overweight and obesity exhibit skin barrier molecular alterations and staphylococcal dysbiosis that suggest early mechanistic clues to this population's increased risk of AD.
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Dermatitis Atópica , Obesidad Materna , Vernix Caseosa , Humanos , Recién Nacido , Femenino , Embarazo , Dermatitis Atópica/patología , Proteínas Filagrina , Obesidad Materna/metabolismo , Obesidad Materna/patología , Vernix Caseosa/metabolismo , Sobrepeso , Piel/patología , Citocinas/metabolismo , Linfopoyetina del Estroma Tímico , Obesidad/patología , Biomarcadores/metabolismoRESUMEN
PIEZO1 is a mechanosensitive cation channel implicated in shear stress-mediated endothelial-dependent vasorelaxation. Since altered shear stress patterns induce a pro-inflammatory endothelial environment, we analyzed transcriptional profiles of human endothelial cells to determine the effect of altered shear stress patterns and subsequent prooxidant and inflammatory conditions on PIEZO1 and mechanosensitive-related genes (MRG). In silico analyses were validated in vitro by assessing PIEZO1 transcript levels in both the umbilical artery (HUAEC) and vein (HUVEC) endothelium. Transcriptional profiling showed that PIEZO1 and some MRG associated with the inflammatory response were upregulated in response to high (15 dyn/cm2) and extremely high shear stress (30 dyn/cm2) in HUVEC. Changes in PIEZO1 and inflammatory MRG were paralleled by p65 but not KLF or YAP1 transcription factors. Similarly, PIEZO1 transcript levels were upregulated by TNF-alpha (TNF-α) in diverse endothelial cell types, and pre-treatment with agents that prevent p65 translocation to the nucleus abolished PIEZO1 induction. ChIP-seq analysis revealed that p65 bonded to the PIEZO1 promoter region, an effect increased by the stimulation with TNF-α. Altogether this data showed that NF-kappa B activation via p65 signaling regulates PIEZO1 expression, providing a new molecular link for prooxidant and inflammatory responses and mechanosensitive pathways in the endothelium.
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BACKGROUND AND OBJECTIVE: Leucocyte- and platelet-rich fibrin has been developed to stimulate wound healing response. However, it is currently unknown whether smoking affects the biological responses elicited by leucocyte- and platelet-rich fibrin on periodontal ligament-derived mesenchymal stromal cells. This study analyzes the kinetics of biomolecule release from leucocyte- and platelet-rich fibrin derived from smokers and nonsmokers and their effect on periodontal ligament cell proliferation and migration as essential biological activities during wound healing. METHODS: Biomolecules present in leucocyte- and platelet-rich fibrin exudates and conditioned media collected from smokers and nonsmokers were analyzed by Luminex arrays. Periodontal ligament-derived mesenchymal stromal cell obtained from one nonsmoker were treated with leucocyte- and platelet-rich fibrin exudates or leucocyte- and platelet-rich fibrin conditioned media derived from both smokers and nonsmokers. The parameters evaluated included cell proliferation, determined by Ki67 immunostaining and migration assessed using transwell assays. Also, cells were treated with nicotine in the presence of fetal bovine serum 10% or leucocyte- and platelet-rich fibrin conditioned media. RESULTS: A similar biomolecular profile was detected in leucocyte- and platelet-rich fibrin exudates and leucocyte- and platelet-rich fibrin conditioned media from smokers and nonsmokers, stimulating (periodontal ligament-derived mesenchymal stromal cell) proliferation, and migration to a comparable degree. Nicotine reduced cell proliferation and migration of periodontal cells; however, this effect was recovered in the presence of leucocyte- and platelet-rich fibrin conditioned media. CONCLUSION: Leucocyte- and platelet-rich fibrin derived from smokers could be an autologous source of biomolecules to stimulate cell biological activities involved in wound healing in smokers who have difficulties in ceasing this habit. Clinical trials are required to evaluate the impact of leucocyte- and platelet-rich fibrin on healing responses in smokers.
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Fibrina Rica en Plaquetas , Humanos , Ligamento Periodontal , Medios de Cultivo Condicionados/farmacología , Nicotina/farmacología , FumarRESUMEN
BACKGROUND: Scientific research is fundamental to the education of medical students. However, their involvement in research is limited. AIM: To describe the perceptions of medical students about facilitators and constraints to perform undergraduate research. MATERIAL AND METOHDS: Medical students attending the Chilean Congress of Medical Students in the Metropolitan Region in 2018, were surveyed. The responses obtained were subjected to a qualitative content analysis and were grouped according to perceptions of facilitators and constraints. RESULTS: The main facilitators reported were linkage with research teachers, personal motivation towards research, and research-oriented curriculum. The main constraints were lack of time for research, lack of access to formal information channels to engage in research, and sub-optimal conditions for research. CONCLUSIONS: The main factor promoting research at the undergraduate level was the link with the teacher, mainly through informal channels. The lack of official information provided through formal instances and lack of time hampers the access to research.
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Humanos , Estudiantes de Medicina , Educación de Pregrado en Medicina , Encuestas y Cuestionarios , Curriculum , Investigación Cualitativa , MotivaciónRESUMEN
BACKGROUND: Scientific research is fundamental to the education of medical students. However, their involvement in research is limited. AIM: To describe the perceptions of medical students about facilitators and constraints to perform undergraduate research. MATERIAL AND METHODS: Medical students attending the Chilean Congress of Medical Students in the Metropolitan Region in 2018, were surveyed. The responses obtained were subjected to a qualitative content analysis and were grouped according to perceptions of facilitators and constraints. RESULTS: The main facilitators reported were linkage with research teachers, personal motivation towards research, and research-oriented curriculum. The main constraints were lack of time for research, lack of access to formal information channels to engage in research, and sub-optimal conditions for research. CONCLUSIONS: The main factor promoting research at the undergraduate level was the link with the teacher, mainly through informal channels. The lack of official information provided through formal instances and lack of time hampers the access to research.
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Educación de Pregrado en Medicina , Estudiantes de Medicina , Curriculum , Humanos , Motivación , Investigación Cualitativa , Encuestas y CuestionariosRESUMEN
BACKGROUND: Major depressive disorder (MDD) is an important independent risk factor for cardiovascular disease. Cumulative data suggest that depressive patients exhibit derangement in regional cerebral blood flow (rCBF), although underlying mechanisms remain mostly unknown. Endothelial dysfunction (ED), defined as different forms of abnormal endothelial activity, plays a key role in the pathogenesis of vascular disease. ED is associated with several clinical conditions characterized by high cardiovascular risk. Diverse ED markers have been found in mood disorders. PURPOSE: To evaluate the association between rCBF and peripheral ED markers in MDD patients, at baseline and after selective serotonin receptor inhibitors (SSRIs) therapy. PATIENTS AND METHODS: Twenty-seven untreated unipolar MDD patients in their first episode were evaluated with the Hamilton Depression Rating Scale (HAM-D) and brain perfusion SPECT at baseline and after 2 months of SSRIs. Statistical Parametric Mapping (SPM) was employed to evaluate rCBF; circulating endothelial cells (CECs), plasma soluble intercellular adhesion molecule (sICAM), and high-sensitivity C-reactive protein (hsCRP) were used as independent covariates. RESULTS: Baseline CECs and sICAM were increased in MDD patients compared with matching controls (p = 0.0001) and hsCRP (p = 0.03). HAM-D scores (21 items) and CECs diminished after SSRI therapy in MDD patients (p < 0.0001). There was a significant rCBF decrease, mainly in deep central structures. HAM-D change was associated with rCBF decrease at the left amygdala, right striatum levels, and Brodmann area 25. CEC change was associated with rCBF at deep brain level and sICAM with large rCBF areas at the left caudate and tectum; hsCRP was associated, to a lesser extent, with the left dorsal striatum and mesencephalic tectum. CONCLUSION: ED markers in patients with MDD are associated with significant changes in rCBF which are features of depression. These findings suggest that systemic damage/activation of the endothelium may contribute to the abnormal rCBF observed in MDD patients.
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Circulación Cerebrovascular/fisiología , Trastorno Depresivo Mayor/sangre , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/fisiopatología , Endotelio Vascular/fisiopatología , Flujo Sanguíneo Regional/fisiología , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Adulto , Circulación Cerebrovascular/efectos de los fármacos , Trastorno Depresivo Mayor/diagnóstico por imagen , Endotelio Vascular/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Flujo Sanguíneo Regional/efectos de los fármacos , Tomografía Computarizada de Emisión de Fotón Único , Adulto JovenRESUMEN
Background: The participation of medical students in research generates professional, scientific, and personal benefits for the student. Aim: To evaluate the interest and opportunities for medical students in Chile to participate in scientific research and their perceptions about factors influencing research. Material and Methods: All students attending the 2018 Chilean Congress for Medical Students were invited to answer a 44 questions survey about interest and opportunities to participate in research. Results: The survey was answered by 489 of the 538 students attending the congress. Eighty five percent referred interest in conducting scientific research, but only 47% had the opportunity to actively participate in a research project. The main research area providing opportunities was epidemiology and the main form to access a research project was through direct contact with a medical professor or researcher. Seventy seven percent of respondents had courses of scientific investigation in their medical curriculum and 92% had a scientific society for medical students in their university. Conclusions: Respondents showed a great deal of interest in participating in scientific research. However, there is a gap between this interest and the available opportunities. Medical professors should promote and facilitate the participation of their students in research.
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Humanos , Estudiantes de Medicina , Educación de Pregrado en Medicina , Universidades , Chile , CurriculumRESUMEN
BACKGROUND: The participation of medical students in research generates professional, scientific, and personal benefits for the student. AIM: To evaluate the interest and opportunities for medical students in Chile to participate in scientific research and their perceptions about factors influencing research. MATERIAL AND METHODS: All students attending the 2018 Chilean Congress for Medical Students were invited to answer a 44 questions survey about interest and opportunities to participate in research. RESULTS: The survey was answered by 489 of the 538 students attending the congress. Eighty five percent referred interest in conducting scientific research, but only 47% had the opportunity to actively participate in a research project. The main research area providing opportunities was epidemiology and the main form to access a research project was through direct contact with a medical professor or researcher. Seventy seven percent of respondents had courses of scientific investigation in their medical curriculum and 92% had a scientific society for medical students in their university. CONCLUSIONS: Respondents showed a great deal of interest in participating in scientific research. However, there is a gap between this interest and the available opportunities. Medical professors should promote and facilitate the participation of their students in research.
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Educación de Pregrado en Medicina , Estudiantes de Medicina , Chile , Curriculum , Humanos , UniversidadesRESUMEN
Resumen: Introducción: La insuficiencia cardíaca crónica (ICC) es una condición compleja asociada a inflamación sistémica y a disfunción endotelial (DE) cuya patogénesis no es bien comprendida. Objetivo: Evaluar una posible relación entre marcadores de DE periférica con la respuesta a terapia de resincronización ventricular (TRV). Método: 20 pacientes con ICC, QRS ≥120ms y fracción de eyección ventricular izquierda (FEVI) ≤35% se estudiaron pre y 6 meses post-TRV con: Minnesota Living with Heart Failure Questionnaire (MLHFQ); test de marcha (TM-6min); Ecocardiografía-2D y SPECT de perfusión gatillado en reposo; proteína C-reactiva ultra sensible (us-PCR); péptido natriurético cerebral (pro-BNP); células endoteliales circulantes (CEC); moléculas de adhesión soluble vascular (sVCAM) e intercelular (sICAM); interleukina-6 (IL-6) y Factor von Willebrand (FvW). Se clasificaron como respondedores o no a TRV según criterios preestablecidos. Resultados: Promedios basales: pro-BNP 5.290pg/ml; us-PCR 1,7ug/mL; MLHFQ 72; TM-6min 391 metros. Las CEC y sICAM estaban sobre límites normales. Post-TRV, el 50% fue respondedor: 11/20 mejoraron ≥1 clase NYHA y ≥10% del TM-6min; ML-HFQ disminuyó (p<0.0001); FEVI mejoró (p=0.003); volumen final sistólico disminuyó (p=0.008) y también pro-BNP (p=0.03). En los respondedores, las CEC disminuyeron, persistiendo elevadas, sobre lo normal. Existieron correlaciones entre cambios de pro-BNP con TM-6min y entre us-PCR con MLHFQ y FvW (p≤0.004 en todas). Conclusiones: En ICC existe evidencia de significativa DE, expresada por sICAM y CEC, biomarcador periférico sensible. Estas disminuyeron 6 meses post-TRV, persistiendo sobre el límite normal. Otros parámetros funcionales e inflamatorios se correlacionaron en el grupo total, sin diferencias entre grupos respondedores y no respondedores.
Abstract: Introduction: Chronic heart failure (CHF) is a complex condition associated with systemic inflammation and endothelial dysfunction (ED) whose pathogenesis is not well understood. Objective: to evaluate a possible relationship between peripheral ED markers and response to cardiac resynchronization therapy (CRT). Method: 20 patients with CHF, QRS ≥120ms and left ventricular ejection fraction (LVEF) ≤35% were studied before and 6 months post-CRT. Minnesota Living with Heart Failure Questionnaire (MLHFQ); walking test (6min-WT); 2D-echocardiography and gated perfusion SPECT at rest; ultra-sensitive C-reactive protein (us-CRP); brain natriuretic peptide (pro-BNP); circulating endothelial cells (CEC); vascular soluble adhesion (sVCAM) and intercellular adhesion molecules (sICAM); interleukin-6 (IL-6) and von Willebrand Factor (vWF) were measured in all subjects. They were classified as responders or not to CRT, according to pre-established criteria. Results: Basal means: pro-BNP 5,290 pg / ml; us-CRP 1.7 ug/mL; MLHFQ 72; 6min-WT 391 meters. The CEC and IL-6 were above normal limits. Post-CRT, 50% were responders: 11/20 improved ≥1 NYHA class and ≥10% increase in 6min-WT; MLHFQ decreased (p <0.0001); LVEF improved (p = 0.003); final systolic volume decreased (p = 0.008) and also pro-BNP (p= 0.03). In responders CEC decreased, persisting over normal limits. There were correlations between changes of pro-BNP with TM-6min and between us-PCR with MLHFQ and vWF (p≤0.004 in all). Conclusions: In CHF there is evidence of significant ED, expressed by sICAM and CEC, a sensitive peripheral biomarker that decreased 6 months post-CRT although persisting above normal limits. Other functional and inflammatory parameters were correlated in the total group, without differences between responders and non-responders.
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Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Terapia de Resincronización Cardíaca/métodos , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Calidad de Vida , Bloqueo de Rama/fisiopatología , Bloqueo de Rama/terapia , Proteína C-Reactiva , Endotelio Vascular/fisiopatología , Biomarcadores , Enfermedad Crónica , Encuestas y Cuestionarios , Células Endoteliales , InflamaciónRESUMEN
Platelets have a major role in clotting activation and contribute to the innate immune response during systemic infections. Human platelets contain tissue factor (TF) and express functional Toll-like receptor 4 (TLR4). However, the role of TLR4 in triggering the procoagulant properties of platelets, upon challenge with bacteria, is yet unknown. Our hypothesis is that E. coli O111-TLR4 interaction activates platelets and elicits their procoagulant activity. We demonstrated that the strain, but not ultrapure LPS, increased surface P-selectin expression, platelet dependent TF procoagulant activity (TF-PCA) and prompted a faster thrombin generation (TG). Blockade of TLR4 resulted in decreased platelet activation, TF-PCA and TG, revealing the participation of this immune receptor on the procoagulant response of platelets. Our results provide a novel mechanism by which individuals with bacterial infections would have an increased incidence of blood clots. Furthermore, the identification of platelet TF and TLR4 as regulators of the effect of E. coli O111 might represent a novel therapeutic target to reduce the devastating consequences of the hemostatic disorder during sepsis.
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Coagulación Sanguínea , Plaquetas/metabolismo , Plaquetas/microbiología , Escherichia coli/metabolismo , Tromboplastina/metabolismo , Receptor Toll-Like 4/metabolismo , Adulto , Anciano , Anticuerpos Monoclonales/farmacología , Coagulación Sanguínea/efectos de los fármacos , Plaquetas/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Humanos , Lipoproteínas/farmacología , Persona de Mediana Edad , Selectina-P/metabolismo , Activación Plaquetaria/efectos de los fármacos , Plasma Rico en Plaquetas/metabolismo , Trombina/metabolismo , Adulto JovenRESUMEN
INTRODUCTION: Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by microvascular damage, inflammation, and fibrosis. It has become increasingly evident that platelets, beyond regulating hemostasis, are important in inflammation and innate immunity. Platelets may be an important source of proinflammatory and profibrotic cytokines in the vascular microenvironment. In this study, we sought to assess the contribution of platelet-derived factors in patients with SSc to the angiogenesis of human dermal microvascular endothelial cells (DMVECs) in a tubule formation assay and to characterize the secretion of profibrotic and proinflammatory cytokines in these platelets. METHODS: We analyzed platelets obtained from 30 patients with SSc and 12 healthy control subjects. Angiogenesis was evaluated in vitro with a DMVEC tubule formation assay on Matrigel and platelet-derived angiogenic factors such as vascular endothelial growth factor (VEGF), 165b isoform (VEGF165b), and cytokine secretion was evaluated. Platelet serotonin content was also determined. RESULTS: When DMVECs were incubated with SSc platelet releasates, tubule formation was significantly inhibited (p < 0.01, t test), and higher expression of endothelin-1 in these cells was observed compared with control subjects (p < 0.05, Mann-Whitney U test). In SSc platelet releasates, VEGF165b was significantly higher (p < 0.05, t test), and the VEGF165b/VEGF ratio was increased compared with that of control subjects. Higher secretion of transforming growth factor ß (p < 0.01, t test) and CD40L (p < 0.01, t test) was observed compared with control subjects. Also, intraplatelet serotonin levels were lower in platelets obtained from patients with diffuse SSc compared with patients with limited SSc and control subjects (p < 0.05, t test). CONCLUSIONS: Our findings suggest that antiangiogenic factors such as VEGF165b, together with proinflammatory and profibrotic factors secreted by platelets, can contribute to the progression of peripheral microvascular damage, defective vascular repair, and fibrosis in patients with SSc.
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Inhibidores de la Angiogénesis/metabolismo , Plaquetas/metabolismo , Mediadores de Inflamación/antagonistas & inhibidores , Mediadores de Inflamación/metabolismo , Neovascularización Patológica/metabolismo , Esclerodermia Sistémica/metabolismo , Adulto , Anciano , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neovascularización Patológica/patología , Esclerodermia Sistémica/patologíaRESUMEN
BACKGROUND: Metabolic syndrome, a chronic condition associated with higher risk of cardiovascular diseases, is increasingly prevalent in young adults. Dyslipidemia, proinflammatory cytokines, endothelial dysfunction signs, and RhoA/Rho-kinase (ROCK) activation are considered risk factors of cardiovascular diseases. The occurrence of these factors in young patients with metabolic syndrome but without type 2 diabetes or hypertension has not been fully studied. The objective of this study was to evaluate young subjects with enlarged waist circumference and dyslipidemia but without type 2 diabetes or hypertension,for markers associated with a higher risk of cardiovascular diseases. METHODS: Thirty-two male patients aged 31 ± 1.3 years diagnosed with metabolic syndrome according to the National Cholesterol Education Program Adult Treatment Panel III guide for enlarged waist circumference, elevated triglycerides, and low HDL levels, but with blood pressure and fasting glucose within normal ranges, were evaluated for RhoA/ROCK activity in leukocytes, serum fatty acid methyl esters profile, proinflammatory cytokines, and oxidative stress markers in addition to thrombin generation and biochemical analysis. Age- and gender-matched healthy subjects were equivalently evaluated. RESULTS: Patients showed higher RhoA/ROCK activity, elevated levels of interleukin-6, soluble CD40L, monocyte chemoattractant protein, and high-sensitivity C-reactive protein (P < 0.001) as well as parameters of endogenous thrombin generation potential (P < 0.05) compared with healthy subjects. Increased thiobarbituric acid reactive substances, advanced oxidation protein product, and insulin levels and low nitric oxide biodisponibility (P < 0.001) were also found in patients as compared with controls. Palmitic acid was one of the saturated fatty acids found to be significantly elevated in patients compared with control subjects (P = 0.0087). CONCLUSIONS: Increased markers of cardiovascular risk are already present in young adults with metabolic syndrome but without type 2 diabetes or hypertension.
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Dislipidemias/enzimología , Endotelio Vascular/metabolismo , Leucocitos/enzimología , Síndrome Metabólico/enzimología , Sobrepeso/enzimología , Quinasas Asociadas a rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Adulto , Factores de Edad , Biomarcadores/sangre , Estudios de Casos y Controles , HDL-Colesterol/sangre , Estudios Transversales , Dislipidemias/sangre , Dislipidemias/diagnóstico , Dislipidemias/fisiopatología , Endotelio Vascular/fisiopatología , Humanos , Mediadores de Inflamación/sangre , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/diagnóstico , Síndrome Metabólico/fisiopatología , Sobrepeso/sangre , Sobrepeso/diagnóstico , Sobrepeso/fisiopatología , Estrés Oxidativo , Ácido Palmítico/sangre , Pronóstico , Factores de Riesgo , Trombina/metabolismo , Triglicéridos/sangre , Circunferencia de la Cintura , Adulto JovenRESUMEN
Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p < 0.0001). PFP- and PPP-, but more significantly PRP-CLT, were positively correlated with age and plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p < 0.001). All these CLT assays had no significant correlations with platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma cholesterol and its potential pathophysiologic and clinical relevance.
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Antifibrinolíticos/farmacología , Plaquetas/metabolismo , Fibrinólisis/efectos de los fármacos , Plasma , Ácido Tranexámico/farmacología , Adolescente , Adulto , Factores de Edad , Anciano , Proteínas Sanguíneas/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Función Plaquetaria/métodos , Factores de Tiempo , Triglicéridos/metabolismoRESUMEN
BACKGROUND: Cocaine use has been related with the development of accelerated atherosclerosis and with an increased risk of cardiac and cerebrovascular events, such as myocardial infarction, sudden cardiac death, and ischemic stroke. The underlying mechanisms leading to these complications are not fully understood, although thrombus formation and altered vascular function are prominent findings. OBJECTIVES: Our aim was to evaluate markers of endothelial dysfunction in chronic cocaine consumers before and after drug withdrawal. PATIENTS/METHODS: We determined circulating endothelial cells (CECs) and plasma levels of stromal cell-derived factor-1 (SDF-1), monocyte chemotactic protein-1(MCP-1), soluble intracellular adhesion molecule (sICAM), high-sensitivity C reactive protein (hsCRP) and endothelin-1(ET-1), in DSM-IV cocaine addicts at baseline and after one month of cocaine abstinence. RESULTS: Cocaine users showed a strikingly higher numbers of CEC (62.35 ± 18.4 vs 8.25 ± 13.8 CEC/mL) and significantly elevated plasma levels for all the markers evaluated as compared to the control group. After cocaine withdrawal, patients improved SDF-1, ET-1, hsCRP and sICAM levels. However, CEC number and MCP-1 plasma levels remained significantly elevated. All the results were adjusted for blood levels of cholesterol and triglycerides and for smoking habit. CONCLUSIONS: Our results demonstrated that chronic cocaine consumption alters several functions of the endothelium towards a pro-thrombotic condition and that some of those functions remain abnormal even after short-term drug withdrawal. These observations support the notion that endothelial dysfunction may play a key role in the pathogenesis of ischemic vascular disease observed in cocaine abusers.
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Trastornos Relacionados con Cocaína/patología , Células Endoteliales/efectos de los fármacos , Síndrome de Abstinencia a Sustancias/patología , Adulto , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Recuento de Células , Quimiocina CXCL12/sangre , Chile , Enfermedad Crónica , Trastornos Relacionados con Cocaína/sangre , Células Endoteliales/metabolismo , Células Endoteliales/patología , Endotelina-1/sangre , Femenino , Humanos , Molécula 1 de Adhesión Intercelular/sangre , Masculino , Persona de Mediana Edad , Síndrome de Abstinencia a Sustancias/sangre , Factores de Tiempo , Regulación hacia Arriba , Adulto JovenRESUMEN
Syrian Golden hamsters develop more severe emphysema than Sprague-Dawley rats after intratracheal instillation of the same dose of elastase/body weight. Although species variations in antielastase defenses may largely explain these results, other variables, such as differences in lung antioxidants, cannot be overlooked since oxidative stress modulates antiprotease activity. We propose that elastase instillation might affect lung glutathione (GSH) metabolism differently in these species. Our aim was to study in hamsters and rats, lung glutathione metabolism at different times, from the stage of diffuse alveolar damage to advanced emphysema. We measured total and oxidized glutathione content as well as activity and expression of enzymes related to GSH synthesis and redox cycling: gamma-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase. Whereas rats showed no significant changes in these measurements, hamsters showed significant derangement in GSH metabolism early after elastase instillation: 25% fall in total GSH (P < 0.05) with no increase in oxidized glutathione associated with reduced enzyme activities 24 h after elastase [60% for gamma-glutamylcysteine synthetase (P < 0.01), 30% for glutathione peroxidase (P < 0.01), and 75% for glutathione reductase (P < 0.001)]. GSH homeostasis was restored at the end of the first week, involving transient increased expression of these enzymes. We conclude that elastase induces significant alterations in GSH metabolism of hamster lungs and no overall change in rat lungs. Although differences in disease severity may account for our findings, the hamster becomes vulnerable to functional inhibition of alpha(1)-antitrypsin by oxidants and thus, even more susceptible to injury than it would be, considering only its low alpha(1)-antitrypsin level.
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Glutatión/metabolismo , Pulmón/metabolismo , Enfisema Pulmonar/metabolismo , Animales , Líquido del Lavado Bronquioalveolar/química , Cricetinae , Modelos Animales de Enfermedad , Regulación Enzimológica de la Expresión Génica , Glutamato-Cisteína Ligasa/genética , Glutamato-Cisteína Ligasa/metabolismo , Disulfuro de Glutatión/metabolismo , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/genética , Glutatión Reductasa/metabolismo , Pulmón/enzimología , Pulmón/patología , Masculino , Mesocricetus , Oxidación-Reducción , Estrés Oxidativo , Elastasa Pancreática , Enfisema Pulmonar/inducido químicamente , Enfisema Pulmonar/patología , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Índice de Severidad de la Enfermedad , Especificidad de la Especie , Factores de Tiempo , alfa 1-Antitripsina/metabolismoRESUMEN
Chemopreventive approaches for the treatment of breast cancer have been validated clinically and with in vitro studies. The combined action of tamoxifen/all-trans retinoic acid was advantageous in MCF-7 cells, reducing cell proliferation, Bcl-2 and c-Myc protein levels and increasing E-Cadherin protein levels and Gap junctional Intercellular Communication. We further investigated their combined effect in the presence of bradykinin, a pro-inflammatory agent, previously reported to contribute to the proliferation of breast cancer cells. Bradykinin increased MCF-7 cell proliferation, c-Myc levels and ERK1/2 activity. The co-incubation of bradykinin-MCF-7 cells with tamoxifen/all-trans retinoic acid reduced cell proliferation, ERK1/2 activity, as well as Bcl-2, c-Myc, and bradykinin receptor-2 levels, without altering the enhanced E-cadherin levels induced by tamoxifen/all-trans retinoic acid. We showed that the anti-tumoral effect of tamoxifen/all-trans retinoic acid is beneficial in MCF-7 breast cancer cells grown in a bradykinin-pro-mitogenic environment, an effect that might be, at least in part, through the MAPK pathway and B2-bradykinin receptor inhibition.
Asunto(s)
Bradiquinina/farmacología , Tamoxifeno/farmacología , Tretinoina/farmacología , Cadherinas/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Receptor de Bradiquinina B2/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
The source and significance of blood-borne tissue factor (TF) are controversial. The presence of TF in platelets was initially attributed to transfer of the protein from other cells (e.g., monocytes) and/or TF-bearing microparticles. Recently, TF-mRNA, neo-synthesis of the protein and TF-dependent procoagulant activity (PCA) have been reported in human platelets. The storage of "encrypted", potentially active TF in circulating, non-stimulated platelets remains debatable. One report strongly suggests that the starting of platelet PCA depends on de novo TF synthesis induced by platelet activation, whereas others provide persuasive evidence that platelets circulate with preformed TF, readily functional upon demand. These findings may have an impact on our current ideas of physiological hemostasis and thrombus formation. In fact, platelets would lead not only the formation of the primary plug, but in this microenvironment they would also contribute to the triggering of thrombin generation, fibrin deposition, clot consolidation and initial protection from fibrinolysis. Much research is needed to validate this platelet-based hemostasis model.
Asunto(s)
Plaquetas/fisiología , Tromboplastina/biosíntesis , Tromboplastina/fisiología , Plaquetas/metabolismo , Hemostasis/fisiología , Humanos , Activación Plaquetaria/fisiología , Tromboplastina/genéticaRESUMEN
The source and significance of bloodborne tissue factor (TF) are controversial. TF mRNA, protein, and TF-dependent procoagulant activity (PCA) have been detected in human platelets, but direct evidence of TF synthesis is missing. Nonstimulated monocyte-free platelets from most patients expressed TF mRNA, which was enhanced or induced in all of them after platelet activation. Immunoprecipitation assays revealed TF protein (mainly of a molecular weight [Mr] of approximately 47 kDa, with other bands of approximately 35 and approximately 60 kDa) in nonstimulated platelet membranes, which also increased after activation. This enhancement was concomitant with TF translocation to the plasma membrane, as demonstrated by immunofluorescence-confocal microscopy and biotinylation of membrane proteins. Platelet PCA, assessed by factor Xa (FXa) generation, was induced after activation and was inhibited by 48% and 76% with anti-TF and anti-FVIIa, respectively, but not by intrinsic pathway inhibitors. Platelets incorporated [(35)S]-methionine into TF proteins with Mr of approximately 47 kDa, approximately 35 kDa, and approximately 60 kDa, more intensely after activation. Puromycin but not actinomycin D or DRB (5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole) inhibited TF neosynthesis. Thus, human platelets not only assemble the clotting reactions on their membrane, but also supply their own TF for thrombin generation in a timely and spatially circumscribed process. These observations simplify, unify, and provide a more coherent formulation of the current cell-based model of hemostasis.
Asunto(s)
Plaquetas/metabolismo , Hemostasis , Tromboplastina/biosíntesis , Coagulación Sanguínea , Humanos , Peso Molecular , Activación Plaquetaria , Transporte de Proteínas , ARN Mensajero/análisis , ARN Mensajero/genética , Tromboplastina/genética , Tromboplastina/metabolismoRESUMEN
Additive effects against tumor cells might be achieved by combining anti-neoplastic agents directed against one or more altered mechanisms in cancer. We investigated the participation of gap junctional intercellular communication (GJIC), which is commonly dysfunctional in tumor cells as a possible mediating mechanism of the effect of all-trans-retinoic acid (RA) and tamoxifen (Tx) in MCF-7 human breast cancer cell lines. The combination of RA + Tx stimulated GJIC in approximately 53 +/- 3% of MCF-7 cells as early as after 6 h of treatment remaining communicated through 144 h of culture. The GJIC enhancement occurred along with immunolocalization of Cx26 and 43 at the membrane of contacting cells and correlated with higher protein levels. Cx40 immunoreactive plaques were detected at cell-to-cell contacts during 48 h of RA + Tx treatment that did not involve higher protein expression, to the contrary, a downregulation occurred after 72 h of treatment. Cell proliferation inhibition upon RA + Tx exposure was observed with optimal effects at 96-120 h of culture with an accumulation of cells primarily in G2/M and G0/G1 cell cycle boundaries. An enhancement of the pre-existing E-cadherin levels was observed after drug exposure along with a downregulation of Bcl-2 and C-myc protein levels and a reduction of telomerase activity, suggesting partial tumor phenotype reversion. Blockage of the RA + Tx-induced GJIC with 18-beta-glycyrrhetinic acid (beta-Gly) prevented in 34% the inhibition of MCF-7 proliferation and the E-cadherin increment in 30% at 96 h of culture. GJIC blockage did not alter the downregulation of Bcl-2, c-Myc, or telomerase activity induced by RA + Tx. Our results showed the participation of GJIC as a mediator mechanism of the combined action of RA and Tx in MCF-7 cells. The chemopreventive modulation of GJIC might represent an approachable alternative for the improvement of cancer therapy.