RESUMO
The complex life cycle of Trichinella spiralis includes the migration of newborn larvae through the bloodstream to their encystment in muscle. The parasite establishes an intimate contact with the erythrocytes of the host both during the migration of the newborn larvae and when encysting, as this parasite causes intense vascularization in the muscle cell. The goal of this work was to study the effects of various concentrations of T. spiralis muscle larvae (ML) on erythrocyte membranes. The treatment was performed by incubating human erythrocytes with equal volume of different concentrations of ML for 30 minutes, with controlled agitation (37°C). The control erythrocytes (with no contact with the larvae) were incubated in the same way with an equal volume of physiological solution. To evaluate the alterations to the erythrocytes by the action of the larvae and in the respective controls, an Erythrocyte Rheometer and a Digital Image Analysis technique were used. The results indicated that when the larval concentration was higher, the aggregation and erythrocyte membrane alterations were also higher. Also, the erythrocyte deformability index and the erythrocyte elasticity increased. The values of isolated cell coefficient varied from 0.51 in the treatment with 100 larvae/ml to 0.91 in the incubation with 1000 larvae/ml. This experiment shows that T. spiralis muscle larvae affect significantly the red blood cell aggregation and the erythrocyte viscoelastic properties.
Assuntos
Membrana Eritrocítica/parasitologia , Músculos/parasitologia , Trichinella spiralis/fisiologia , Triquinelose/parasitologia , Animais , Membrana Eritrocítica/química , Feminino , Humanos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Camundongos , Trichinella spiralis/crescimento & desenvolvimento , Triquinelose/sangueRESUMO
Few vaccine adjuvants have been approved for human use although several are currently being studied in preclinical and clinical trial. MPL is a toll-like receptor agonist able to trigger a high and persistent antibody response via-TLR-4 while QS-21 activates the NLRP3 inflammasome. Data suggest that there is a cross-talk between Notch and TLR signaling pathways modulating the polarization of the immune response in a MyD88-dependent manner. However, the role of Notch on the mechanism action of immunogenic adjuvants has not been addressed yet. This study aims to evaluate the in vitro toxicity and inflammatory response triggered by MPL and QS-21 using an in vitro human cell co-culture model and to determine whether NFκB or Notch signaling pathways are involved in their mechanism of immunotoxicity. In order to do this, we evaluated the effect of QS- 21/MPL alone or in combination using a co-culture of PBMC and HUVEC using cytotoxicity, surface expression of ECAMs, cell adhesion and cytokine release, NF-κB activation and NOTCH1 expression as observation endpoints. We found that both MPL and QS-21 were cytotoxic at concentrations over 5 µg/mL. Both adjuvants were able to trigger the expression of ECAMs and induce firm adhesion of PBMC to the endothelium. QS-21 and MPL combination demonstrated a synergistic effect on cellular recruitment and cytokine release generating a switch from Th2 to Th1 cytokine profile. Both MPL and QS-21 by themselves were able to generate significant NF-κB activation. However, this effect was not observed when both adjuvants were combined. On the contrary, the adjuvants alone and combined induced an overexpression of NOTCH-1. This is an important finding, as it provides new evidence that these adjuvants could modulate reactogenicity of vaccines through Notch signaling.
Assuntos
Adjuvantes Imunológicos/toxicidade , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Lipídeo A/análogos & derivados , Receptor Notch1/genética , Saponinas/toxicidade , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Citocinas/metabolismo , Interações Medicamentosas , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Leucócitos Mononucleares/fisiologia , Lipídeo A/toxicidade , NF-kappa B/metabolismoRESUMO
Antecedentes: el intento de suicidio es el principal factor de riesgo de muerte por suicidio. La Organización Mundial de la Salud sugiere grupos de apoyo como intervención para esta población. Objetivo: Este estudio tuvo como objetivo determinar la eficacia de los grupos de apoyo de pares para sobrevivientes de intento de suicidio (SOSA). Método: Revisión sistemática (PROSPERO ID: CRD42022307581). Resultados: En total se identificaron 946 artículos potenciales, se revisaron 81 textos completos y se incluyó un artículo. El artículo informa sobre un estudio piloto abierto con evaluaciones pre y post intervención, sin grupo de control y con alto riesgo de sesgo. Esta es una intervención prometedora, porque los resultados mostraron una disminución de la ideación suicida (d=0,33), y del intento de suicidio (d=0,31). El pequeño número de investigaciones empíricas limita las generalizaciones. Conclusión: El nivel de certeza de la evidencia es bajo (baja certeza), por lo tanto, el grado de recomendación corresponde a evidencia insuficiente (I), para recomendar esta estrategia para las políticas públicas. En este artículo se analizan las razones de estos resultados y los posibles caminos para avanzar en este campo.
Background: Suicide attempt is the main risk factor for death by suicide. The World Health Organization (WHO) suggests support groups as an intervention for this population. Objective: This study aimed to assess the efficacy of peer-support groups for survivors of suicide attempt (SOSA). Method: Systematic review (PROSPERO ID: CRD42022307581). Results: In total, 946 potential articles were identified, 81 full texts were reviewed, and one article was included. The article reported an open-label pilot study with pre- and post-intervention evaluations, without a control group, and with a high risk of bias. This is a promising intervention because the results showed decreased suicidal ideation (d=0.33) and suicide attempt (d=0.31). The small number of empirical investigations limit generalizations. Conclusion: The level of certainty of evidence is low (low certainty); therefore, the grade of recommendation corresponds to insufficient evidence (I) to recommend this strategy for public policies. The reasons for these results and possible paths to advance the field are discussed in this article.
RESUMO
Liver preconditioning by a docosahexaenoic acid (DHA) and triiodothyronine (T3) combined protocol underlies peroxisome-proliferator activated receptor α (PPARα)-fibroblast growth factor 21 (FGF21) upregulation, the study of the regulatory mechanisms involved being the aim of this work. Combined DHA (daily doses of 300 mg kg-1 for 3 days)-T3 (0.05 mg kg-1 at the fourth day) administration elicited higher levels of liver DHA and serum T3, with enhanced hepatic nuclear/cytosolic PPARα ratios, upregulation of FGF21 and ß-Klotho expression, and a small reduction in that of FGF receptor 1 (FGFR1), compared with the respective controls. Concomitantly, the components of the FGF21 cascade extracellular-signal-regulated kinase 1/2 (ERK1/2), FGF receptor substrate 2α (FRS2α), cFos, ribosomal S6 kinase 1 (RSK1), liver kinase B1 (LKB1), and AMP-activated protein kinase (AMPK) were activated. The upregulation of liver PPARα-FGF21-AMPK signaling by the combined DHA-T3 protocol resulted in values significantly higher than those elicited by the addition of the data obtained for DHA and T3 alone. It is concluded that combined DHA-T3 supplementation achieves synergistic effects on liver PPARα-FGF21-AMPK signaling, which may result in significant metabolic changes associated with energy expenditure that are of importance in the treatment of obesity and other metabolic disorders.
Assuntos
Ácidos Docosa-Hexaenoicos/administração & dosagem , Fatores de Crescimento de Fibroblastos/metabolismo , Glucuronidase/metabolismo , Fígado/metabolismo , Doenças Metabólicas/tratamento farmacológico , Tri-Iodotironina/administração & dosagem , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Metabolismo Energético/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/genética , Glucuronidase/genética , Humanos , Proteínas Klotho , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Doenças Metabólicas/fisiopatologia , PPAR alfa/genética , PPAR alfa/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
Beta-thalassaemia is a hereditary hemolytic disease, in which each clinic phenotype encompasses a heterogenic group of genetic alterations resulting in beta-globin chain synthesis decrease or absence in red blood cells. Studies on beta-thalassaemia carriers suggest the existence of decreased red cell deformability. The erythrocyte deformability in the blood stream is a well-known fact regarding blood circulation efficiency. Red blood cells may be considered to be viscoelastic and their behavior may be described according to complex viscoelastic parameters when they undergo oscillatory stresses. This dynamic behavior is physiologically important due to the in vivo pulsatile blood flow. The aim of the present work was to evaluate complex erythrocyte viscoelastic parameters in patients suffering from heterozygous beta-thalassaemia in comparison with healthy individuals. Our results reveal that even though thalassaemia erythrocytes show a decreased deformability in the stationary state, in a dynamic state, hemorheological alterations are only evident at low oscillatory frequencies, i.e., at lower frequencies in contrast with the normal heart rate (60 cycles/min = 1 Hz), producing no significant alterations at increased heart rate.
Assuntos
Deformação Eritrocítica/fisiologia , Membrana Eritrocítica/fisiologia , Talassemia beta/sangue , Anemia Ferropriva/sangue , Elasticidade , Feminino , Hemorreologia , Humanos , Masculino , Estatísticas não ParamétricasRESUMO
A new method to find directly complex viscoelastic parameters (CVP) of red blood cells (RBC) is presented in this paper. Experimental determinations were carried out in an Erythrodeformeter (Rasia et al., 1986) operating in oscillating mode (0.5 to 3.5 Hz). The Erythrodeformeter performs direct determination of CVP of erythrocytes undergoing sinusoidal shear stresses by laser diffractometry. The measurements lead to the determination of mean values of the four components of erythrocyte complex viscoelasticity. The influence of the alterations induced on erythrocyte membrane by vegetable lactins (Ulex europaeus, wheat germ agglutinin and Enterolobium contorticilicum seeds) was analyzed to verify the sensitivity of this method. Differences observed between the CVP parameters of treated cells and the ones corresponding to control samples (non treated cells) are analyzed. Results obtained from cells treated with wheat germ agglutinin agree with observations published by Smith and Hochmuth (1982). Determinations of RBC complex viscoelasticity carried out by laser diffractometry could become an important tool to understand the influence of the factors associated with alterations of the rheologic properties of RBC membrane, which can affect the in vivo blood flow.
Assuntos
Deformação Eritrocítica/efeitos dos fármacos , Eritrócitos/fisiologia , Lectinas/farmacologia , Adulto , Elasticidade , Eritrócitos/efeitos dos fármacos , Humanos , Lasers , ViscosidadeRESUMO
Spectral and multiphoton imaging is the preferred approach for non-invasive study allowing deeper penetration to image molecular processes in living cells. But currently available fluorescence microscopic techniques based on fluorescence intensity, such as confocal or multiphoton excitation, cannot provide detailed quantitative information about the dynamic of complex cellular structure (molecular interaction). Due to the variation of the probe concentration, photostability, cross-talking, its effects cannot be distinguished in simple intensity images. Therefore, Time Resolved fluorescence image is required to investigate molecular interactions in biological systems. Fluorescence lifetimes are generally absolute, sensitive to environment, independent of the concentration of the probe and allow the use of probes with overlapping spectra but that not have the same fluorescence lifetime. In this work, we present the possibilities that are opened up by Fluorescence Lifetime Imaging Microscopy, firstly to collect images based on fluorescence lifetime contrast of GFP variants used as a reporter of gene expression in chondrocytes and secondly, to measure molecular proximity in erythrocyte (glycophorin/membrane) by Fluorescence Resonance Energy Transfer (FLIM-FRET).
Assuntos
Eritrócitos/ultraestrutura , Microscopia de Fluorescência por Excitação Multifotônica , Corantes Fluorescentes , Humanos , Fotodegradação , Espectrometria de Fluorescência , Engenharia TecidualRESUMO
Rheological alterations produced during the storage of human erythrocytes were studied by means of in vitro viscoelastic parameters. Weekly aliquots of packed red blood cells (PRBC) and whole blood (WB) stored in CPD-adenine were studied for 35 days. Samples were analyzed in Erythrodeformeter both in stationary and oscillating regime. We found that erythrocyte deformability index and all complex viscoelastic parameters are modified by storage. Plasma viscosity and blood viscosity were measured in a cone/plate Viscometer. Blood viscosity at high shear rates shows variations related to conservation time, which are in correlation with the variations observed in the erythrocyte deformability index. Blood viscosity at low shear rate decreases during storage. Rheological tests would demonstrate some alterations in the structural properties of erythrocyte stored as PRBC. These alterations are less than those found in WB. We conclude that plasmatic proteins play a predominant role in the alteration of rheological behavior of erythrocytes during their storage. Consequently, it is important to evaluate not only cellular components but also plasma.
Assuntos
Preservação de Sangue , Deformação Eritrocítica , Eritrócitos , Adulto , Elasticidade , HumanosRESUMO
This study investigates the effects produced by an increased concentration of glucose in a suspending medium on the erythrocytes Information Theory quantifiers. Erythrocytes, which were obtained from eight healthy volunteers, were washed and incubated in vitro with glucose solutions at different concentrations. The measured Wavelet-based Information Theory quantifiers include the Relative Wavelet Energy (RWE), the Normalized Total Wavelet Shannon Entropy (NTWS), MPR-Statistical Complexity Measure (SCM) and entropy-complexity plane. The results show that the increase in glucose concentration does not produce significant changes on the RWE, while significant ones on the NTSE, which combined with SCM values allow to identify different behaviour for all the different populations in the entropy-complexity plane. Modification in the hemorheological properties of cells could be clearly detected with these Wavelet-based Information Theory quantifiers.