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1.
Medicine (Baltimore) ; 99(7): e19109, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32049823

RESUMO

BACKGROUND: Mild hemolysis is difficult to determinate by traditional methods, and its role in Gilbert's syndrome (GS) is unclear. The main aims were to inspect the erythrocyte (RBC) survival in GS by using Levitt's carbon monoxide (CO) breath test and to assess its contribution to unconjugated hyperbilirubinemia. METHODS: Fifty subjects with GS and 1 with type-II Crigler-Najjar syndrome (CN2) received RBC lifespan measurement with Levitt's CO breath test. Mean RBC lifespan was compared with normal referral value. Correlations of serum total bilirubin (TB) with RBC lifespan, blood panel data, demographic factors, and uridine diphosphate glucuronosyltransferase (UGT1A1) mutation load were calculated by Spearman analysis. Susceptibility factors for mild hemolysis were analyzed by multivariate regression analysis. RESULTS: The mean RBC lifespan of the GS subjects was significantly shorter than the normal reference value (95.4 ±â€Š28.9 days vs 126 days; t = -7.504, P < .01), with 30.0% below the lower limit of the normal reference range (75 days). The RBC lifespan of the participant with CN2 was 82 days. Serum TB correlated positively with UGT1A1 mutation load (γ = 0.281, P = .048), hemoglobin (γ = .359, P = .010) and hematocrit (γ = 0.365, P = .010), but negatively with RBC lifespan (γ = -0.336, P = .017). No significant susceptibility factors for mild hemolysis were found. CONCLUSIONS: The results indicate that mild hemolysis indeed, exists in a portion of patients with GS and might serve as an important contributor to unconjugated hyperbilirubinemia in addition to UGT1A1 polymorphism. Further studies on the mechanism and the potential risks in various medical treatments might be wanted.


Assuntos
Monóxido de Carbono/análise , Doença de Gilbert/complicações , Hemólise , Hiperbilirrubinemia/etiologia , Adulto , Testes Respiratórios/instrumentação , Eritrócitos/fisiologia , Feminino , Humanos , Hiperbilirrubinemia/sangue , Masculino , Pessoa de Meia-Idade
2.
Exp Parasitol ; 210: 107842, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31978393

RESUMO

Free-living amoebae of the genus Acanthamoeba have been associated with keratitis and encephalitis. Some factors related to their pathogenic potential have been described, including the release of hydrolytic enzymes, and the adhesion and phagocytosis processes. However, other factors such as their effect over the hemodynamics and microcirculation elements have not been fully investigated. This work determines the in vitro activity of potentially pathogenic environmental isolates of Acanthamoeba genotype T4 and T5 over erythrocytes and platelets. The hemolytic activity (dependent and independent of contact), as well as the production of ADP of ten environmental isolates of Acanthamoeba obtained from dental units, combined emergency showers, dust, and hospital water, were measured. Tests were carried out over erythrocytes in suspension and blood agar plates, incubated at 4 °C, room temperature and 37 °C. Erythrophagocytosis and platelet aggregation assays were also performed. Live trophozoites of all of the isolates tested showed a hemolytic activity that was temperature-dependent. Over erythrocytes in suspension, variable hemolysis percentages were obtained: a maximum of 41% and a minimum of 15%. Regarding hemolysis over agar plates, two patterns of hemolysis were observed: double and simple halos. Conditioned medium and crude extracts of trophozoites did not show hemolytic activity. Erythrophagocytosis by Acanthamoeba was also observed; however, no production of ADP was determined by the employed methodology.


Assuntos
Acanthamoeba/fisiologia , Plaquetas/parasitologia , Meio Ambiente , Eritrócitos/parasitologia , Acanthamoeba/classificação , Acanthamoeba/genética , Acanthamoeba/patogenicidade , Difosfato de Adenosina/metabolismo , Doenças Transmissíveis Emergentes/parasitologia , Meios de Cultivo Condicionados , Eritrócitos/fisiologia , Genótipo , Hemólise , Humanos , Fagocitose , Agregação Plaquetária , Temperatura Ambiente , Trofozoítos/classificação , Trofozoítos/genética , Trofozoítos/patogenicidade , Trofozoítos/fisiologia
3.
Adv Exp Med Biol ; 1131: 625-648, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31646528

RESUMO

Free Calcium (Ca2+) is an important and universal signalling entity in all cells, red blood cells included. Although mature mammalian red blood cells are believed to not contain organelles as Ca2+ stores such as the endoplasmic reticulum or mitochondria, a 20,000-fold gradient based on a intracellular Ca2+ concentration of approximately 60 nM vs. an extracellular concentration of 1.2 mM makes Ca2+-permeable channels a major signalling tool of red blood cells. However, the internal Ca2+ concentration is tightly controlled, regulated and maintained primarily by the Ca2+ pumps PMCA1 and PMCA4. Within the last two decades it became evident that an increased intracellular Ca2+ is associated with red blood cell clearance in the spleen and promotes red blood cell aggregability and clot formation. In contrast to this rather uncontrolled deadly Ca2+ signals only recently it became evident, that a temporal increase in intracellular Ca2+ can also have positive effects such as the modulation of the red blood cells O2 binding properties or even be vital for brief transient cellular volume adaptation when passing constrictions like small capillaries or slits in the spleen. Here we give an overview of Ca2+ channels and Ca2+-regulated channels in red blood cells, namely the Gárdos channel, the non-selective voltage dependent cation channel, Piezo1, the NMDA receptor, VDAC, TRPC channels, CaV2.1, a Ca2+-inhibited channel novel to red blood cells and i.a. relate these channels to the molecular unknown sickle cell disease conductance Psickle. Particular attention is given to correlation of functional measurements with molecular entities as well as the physiological and pathophysiological function of these channels. This view is in constant progress and in particular the understanding of the interaction of several ion channels in a physiological context just started. This includes on the one hand channelopathies, where a mutation of the ion channel is the direct cause of the disease, like Hereditary Xerocytosis and the Gárdos Channelopathy. On the other hand it applies to red blood cell related diseases where an altered channel activity is a secondary effect like in sickle cell disease or thalassemia. Also these secondary effects should receive medical and pharmacologic attention because they can be crucial when it comes to the life-threatening symptoms of the disease.


Assuntos
Canais de Cálcio , Animais , Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Eritrócitos/fisiologia , Doenças Hematológicas/fisiopatologia , Humanos , Mutação
4.
Chemosphere ; 240: 124910, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31561159

RESUMO

The micronucleus test has been applied for more than three decades in tadpoles, generating an early warning of environmental quality. In this study, we reviewed 48 articles on the micronucleus test in tadpoles, published between 1987 and 2018. The findings reveal that pesticides have been the main topic discussed in the induction of micronucleus and other nuclear abnormalities in anuran larvae to the detriment of the widespread use of compounds used in agriculture. In addition to pesticides, a number of other xenobiotic agents have been targeted for genotoxic damage, such as heavy metals, radiation and wastewater. An appeal is reported to environmental contaminants, which when released naturally into the environment or because of human activities may contaminate aquatic habitats, threatening populations of tadpoles that depend on these environments for their survival. Larvae can bioaccumulate these contaminants that cause progressive impacts, ranging from DNA damage to metamorphosis delays, as well as malformations. We found that Argentina is the main driving force for the application of this test in anuran larvae along with Brazil. Different erythrocyte malformations have been reported for the erythrocyte nuclear abnormalities test, binucleated cells, nuclear buds, notched, lobed, reniform, nuclear bebbled, anucleated, picnotic and apoptotic cells are the most cited. In summary, the presence of chemical or physical agents, along with other disturbances of the habitat, can have a significant impact on the life history of the species, contributing to the decline of anuran populations.


Assuntos
Anuros/genética , Ecotoxicologia/tendências , Eritrócitos/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Testes para Micronúcleos , Agricultura , Animais , Argentina , Brasil , Dano ao DNA , Ecossistema , Monitoramento Ambiental/métodos , Poluição Ambiental , Eritrócitos/patologia , Eritrócitos/fisiologia , Metais Pesados/toxicidade , Metamorfose Biológica/efeitos dos fármacos , Publicações Seriadas , Poluentes Químicos da Água/toxicidade
5.
Res Vet Sci ; 127: 65-75, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31678455

RESUMO

This study was planned to investigate TD (Tibial dyschondroplasia) on the potential MAPK signaling pathway and angiogenesis related genes. Forty-eight broilers were allotted into control (C) and treatment (T) groups of 2, 6 and 15 days as C1, C2, C3, T1, T2 and T3. The histopathology results revealed that tibiotarsus bone of chickens had more lesions on day 6 (T2 group). The chondrocytes were disordered, and the size, shape and proliferation were affected. Transcriptome results revealed that differentially expressed genes (DEGs) identified were 63, 1026, 623, 130, 141 and 146 in C1 (2 days control vs 6 days control); C2 (2 days control vs 15 days control); C3 (6 days control vs 15 days control); T1 (2 days treatment vs 6 days treatment); T2 (2 days treatment vs 15 days treatment) and T3 (6 days treatment vs 15 days treatment) groups respectively. Whereas, 10 angiogenesis related-genes RHOC, MEIS2, BAIAP2, TGFBI, KLF2, CYR61, PTPN11, PLXNC1, HSPH1 and NRP2 were downregulated on day 6 in the treatment group. The pathway which was found enriched in the control and treatment groups was MAPK signaling pathway. Therefore selected 10 MAPK signaling pathway-related genes RAC2, MAP3K1, PRKCB, FLNB, IL1R1, PTPN7, RPS6KA, MAP3K6, GNA12 and HSPA8 which were found significantly downregulated in the treatment group on day 6. It is concluded that angiogenesis and MAPK signaling pathway related genes has an essential role in TD, as those top screened genes found downregulated in the thiram fed chickens when TD observed severed on day 6.


Assuntos
Galinhas , Eritrócitos/fisiologia , Fungicidas Industriais/efeitos adversos , Sistema de Sinalização das MAP Quinases/genética , Osteocondrodisplasias/veterinária , Doenças das Aves Domésticas/genética , Tiram/efeitos adversos , Animais , Perfilação da Expressão Gênica/veterinária , Neovascularização Patológica/genética , Osteocondrodisplasias/induzido quimicamente , Osteocondrodisplasias/genética , Osteocondrodisplasias/patologia , Doenças das Aves Domésticas/induzido quimicamente , Doenças das Aves Domésticas/patologia , Tíbia/patologia
6.
Environ Sci Pollut Res Int ; 26(36): 36903-36912, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31745778

RESUMO

Global warming and indiscriminate usages of pesticides are notable concern to all. The present study has been conducted to evaluate the effects of high temperature on acute toxicity of sumithion in adult zebrafish. A 2-day renewal bioassay system was used to determine the 96 h LC50 value of sumithion at three temperature regimes, such as 25 °C, 30 °C, and 35 °C. Blood glucose (mg/dL) level was measured in control (0.0 mg/L) and low concentration (1.0 mg/L) of sumithion during the determination of LC50 in three temperature conditions. In addition, micronucleus (MN), erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA) tests were performed in the blood erythrocytes. The 96 h LC50 value of sumithion for zebrafish was significantly lower at 35 °C, which indicates that the toxicity of sumithion increases at higher temperature. Blood glucose level was significantly increased by sumithion in all temperature conditions, while it was significantly higher in the highest (35 °C) temperature compared to the lowest (25 °C) temperature in both control and sumithion-treated fish. Similarly, frequencies of MN, ENA, and ECA were elevated by sumithion in all temperature conditions, whereas it was significantly raised in the highest (35 °C) temperature compared to the lowest (25 °C) temperature in both control and sumithion treated fish. With increasing temperature in exposure to sumithion, dissolved oxygen decreased significantly, whereas free CO2 increased significantly. On the other hand, no distinct changes were observed in pH and total alkalinity during the experimental period. Therefore, it can be inferred that increasing temperature enhances the toxicity of sumithion in the zebrafish.


Assuntos
Fenitrotion/toxicidade , Inseticidas/toxicidade , Temperatura Ambiente , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Eritrócitos/fisiologia , Temperatura Alta , Dose Letal Mediana , Praguicidas , Testes de Toxicidade Aguda , Água
7.
Comput Math Methods Med ; 2019: 4235937, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31531122

RESUMO

The aim of this paper consists in the derivation of an analytic formula for the hydraulic resistance of capillaries, taking into account the tube hematocrit level. The consistency of the derived formula is verified using Finite Element simulations. Such an effective formula allows for assigning resistances, depending on the hematocrit level, to the edges of networks modeling biological capillary systems, which extends our earlier models of blood flow through large capillary networks. Numerical simulations conducted for large capillary networks with random topologies demonstrate the importance of accounting for the hematocrit level for obtaining consistent results.


Assuntos
Capilares/fisiologia , Circulação Cerebrovascular/fisiologia , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Encéfalo/irrigação sanguínea , Simulação por Computador , Eritrócitos/fisiologia , Análise de Elementos Finitos , Hematócrito , Humanos , Conceitos Matemáticos , Modelos Cardiovasculares , Resistência Vascular/fisiologia
8.
J Med Syst ; 43(10): 316, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506773

RESUMO

This work proposes a non-invasive method to estimate the number of red blood cells in the blood. To achieve the development of this research, first, a photosensitive device was designed, which is formed by a phototransistor with a transparent casing allowing the red light coming from a red LED to penetrate the sensor. This means, that when the intensity of the light varies, the amount of current flowing through the sensor also changes. In consequence, this variation in electric current causes a variation on the voltage drop across the connections of a resistor, which is read by a microcontroller that calculates the number of red blood cells. Second, some formulas were established to represent the relationship between the extreme points of a data set obtained during a sampling process. Finally, to verify the device operation, a sampling process was performed in volunteer patients (range 18-84 years) with venous blood samples run on a laboratory hematology analyzer, a total 68 measurements were made to people of different ages and genders, of which 34 are females and 34 are males.


Assuntos
Contagem de Células Sanguíneas/instrumentação , Contagem de Células Sanguíneas/métodos , Raios Infravermelhos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Eritrócitos/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
PLoS Comput Biol ; 15(8): e1007231, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31469820

RESUMO

Capillaries are the prime location for oxygen and nutrient exchange in all tissues. Despite their fundamental role, our knowledge of perfusion and flow regulation in cortical capillary beds is still limited. Here, we use in vivo measurements and blood flow simulations in anatomically accurate microvascular network to investigate the impact of red blood cells (RBCs) on microvascular flow. Based on these in vivo and in silico experiments, we show that the impact of RBCs leads to a bias toward equating the values of the outflow velocities at divergent capillary bifurcations, for which we coin the term "well-balanced bifurcations". Our simulation results further reveal that hematocrit heterogeneity is directly caused by the RBC dynamics, i.e. by their unequal partitioning at bifurcations and their effect on vessel resistance. These results provide the first in vivo evidence of the impact of RBC dynamics on the flow field in the cortical microvasculature. By structural and functional analyses of our blood flow simulations we show that capillary diameter changes locally alter flow and RBC distribution. A dilation of 10% along a vessel length of 100 µm increases the flow on average by 21% in the dilated vessel downstream a well-balanced bifurcation. The number of RBCs rises on average by 27%. Importantly, RBC up-regulation proves to be more effective the more balanced the outflow velocities at the upstream bifurcation are. Taken together, we conclude that diameter changes at capillary level bear potential to locally change the flow field and the RBC distribution. Moreover, our results suggest that the balancing of outflow velocities contributes to the robustness of perfusion. Based on our in silico results, we anticipate that the bi-phasic nature of blood and small-scale regulations are essential for a well-adjusted oxygen and energy substrate supply.


Assuntos
Encéfalo/irrigação sanguínea , Eritrócitos/fisiologia , Microvasos/fisiologia , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Capilares/anatomia & histologia , Capilares/fisiologia , Circulação Cerebrovascular/fisiologia , Biologia Computacional , Simulação por Computador , Feminino , Hematócrito , Camundongos , Camundongos Endogâmicos C57BL , Microvasos/anatomia & histologia , Modelos Cardiovasculares , Modelos Neurológicos , Vasodilatação/fisiologia
11.
Nutr. hosp ; 36(4): 926-930, jul.-ago. 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-184720

RESUMO

Introducción: cualquier situación de estrés, entre las cuales se incluye la realización de ejercicio físico, implica la posibilidad de una excesiva producción de radicales libres y, por acción de estos, un estrés oxidativo en las células. Para combatir estos efectos, las células disponen de unos mecanismos de defensa denominados sistemas antioxidantes. Objetivos: el objetivo del presente estudio se basa en analizar los posibles cambios fisiológicos en relación a parámetros relacionados con el estrés oxidativo (MDA) y con la actividad antioxidante (vitamina A, vitamina C y vitamina E) en los eritrocitos de jugadores profesionales de fútbol, en comparación con sujetos no entrenados. Métodos: cuarenta y dos varones divididos en 21 jugadores de fútbol (SG) (24,95 ± 3,03 años) y 21 estudiantes sedentarios (CG) (23,71 ± 2,42 años) participaron en el estudio. Se les evaluaron los niveles basales de MDA, vitamina C, vitamina A y vitamina E en eritrocitos, así como las características antropométricas y el VO2max. Resultados: se observaron diferencias significativas en las características antropométricas (p < 0,05) y VO2max (p > 0,01). SG presentó niveles estadísticamente inferiores de MDA (p > 0,01), vitamina C (p > 0,05), vitamina E (p > 0,05) y vitamina A (p > 0,01). Conclusiones: existe un mayor estrés oxidativo en jugadores de fútbol que en sedentarios, por lo que puede ser necesaria una suplementación con antioxidantes en este grupo


Introduction: the situations of stress among which physical exercise is included imply the possibility of an excessive production of free radicals and, by their action, an oxidative stress in the cells. To combat these effects, cells have defense mechanisms called antioxidant systems. Objectives: the objective of this study is to analyze the possible physiological changes in relation to parameters related to oxidative stress (MDA) and antioxidant activity (vitamin A, vitamin C and vitamin E) in the erythrocytes of professional soccer players, in comparison with untrained subjects. Methods: forty-two men divided into 21 soccer players (SG) (24.95 ± 3.03 years) and 21 sedentary students (CG) (23.71 ± 2.42 years) participated in the study. Their basal levels of MDA, vitamin C, vitamin A and vitamin E in erythrocytes, as well as their anthropometric characteristics and VO2max, were evaluated. Results: significant differences were observed in the anthropometric characteristics (p < 0.05) and VO2max (p > 0.01). SG presented statistically lower levels of MDA (p > 0.01), vitamin C (p > 0.05), vitamin E (p > 0.05) and vitamin A (p > 0.01). Conclusions: there is higher oxidative stress in soccer players than in sedentary players and it may be necessary to supplement with antioxidants in this group


Assuntos
Humanos , Masculino , Adulto , Futebol/psicologia , Estresse Oxidativo , Eritrócitos/fisiologia , Antioxidantes/metabolismo , Consumo de Oxigênio/fisiologia , Comportamento Sedentário , Radicais Livres , Antropometria , Vitamina A , Ácido Ascórbico , Vitamina E , Teste de Esforço , Esforço Físico
12.
Vox Sang ; 114(6): 576-587, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31281973

RESUMO

BACKGROUND AND OBJECTIVES: The accumulation of microvesicles in erythrocyte concentrates during storage or irradiation may be responsible for clinical symptoms such as inflammation, coagulation and immunization. Our aim was to determine whether any of the cluster of differentiation (CD) molecules responsible for important functions are present on microvesicles, and if their expression level is dependent on the storage period of erythrocyte concentrates. MATERIAL AND METHODS: Erythrocyte microvesicles were isolated from 'fresh' (2nd day) and 'old' (42nd day) stored erythrocyte concentrates. Qualitative cytometric analysis of 0·5 µm, erythrocyte-derived, PS-exposing vesicles was performed using the annexin V-FITC, anti-CD235a-PE antibody and calibrated beads. The microvesicles were also visualized under a confocal microscope. The expression of the molecules CD235a, CD44, CD47, CD55, CD59 and of phosphatidylserine (PS) was compared using flow cytometry. Measurements of microvesicle phagocytosis by human monocytes were carried out using a flow cytometer and a confocal microscope. RESULTS: The analysis of the microvesicles with calibration beads allowed us to identify these structures with a diameter of about 0·5 µm in the 'fresh' and 'old' samples. At day 2, the microvesicles had elevated expression levels of CD47, reduced expression levels of PS, CD55 and CD59. The phagocytosis index was higher for the microvesicles isolated from the 42-day-old erythrocyte concentrates. CONCLUSION: This research may bring us closer to understanding the factors responsible for erythrocyte ageing and to evaluate the quality of stored red blood concentrates intended for transfusion.


Assuntos
Transfusão de Sangue , Eritrócitos/fisiologia , Vesículas Extracelulares/fisiologia , Glicoproteínas de Membrana/fisiologia , Monócitos/fisiologia , Fagocitose , Antígeno CD47/análise , Antígeno CD47/genética , Antígenos CD55/análise , Antígenos CD55/genética , Antígenos CD59/análise , Antígenos CD59/genética , Eritrócitos/citologia , Eritrócitos/metabolismo , Citometria de Fluxo , Expressão Gênica , Humanos , Receptores de Hialuronatos/análise , Receptores de Hialuronatos/genética , Fosfatidilserinas/análise
13.
Adv Gerontol ; 32(1-2): 55-59, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31228368

RESUMO

The dynamics of transformation and osmotic fragility (OF) of erythrocytes in the blood of rats of different ages (6, 12 and 24 months) were studied using small-angle light scattering method and the indices of erythrocytes transformation were calculated. The heterogeneity of the erythrocytes population in the blood increased with age: the proportion of normal and highly resistant flattened discocytes decreased. The proportion of flattened discocytes was the lowest in 12 months of aged rats. Correspondently, the proportion of the erythrocytes altered shapes, both reversible (stomatocytes) and irreversible (spherocytes), increased with age. It is speculated that the erythrocytes transformation developed via the stomatocytic pathway. The tendency to an increase in the level of erythrocytes OF between the rat ages was only found. The indices of transformation, reversible and irreversible transformation increased with age, except for the reversibility index, which was the highest in 6 months of age rats, significantly unchanged in 12 months of age rats, and decreased almost in 3,5 times in 24 months compared to 6 months of aged rats. In 6 months` aged rats, a lower index of transformation was observed against a background of a higher index of reversibility compared to the other age groups of rats.


Assuntos
Envelhecimento , Eritrócitos , Envelhecimento/fisiologia , Animais , Contagem de Eritrócitos , Eritrócitos/fisiologia , Fragilidade Osmótica , Ratos
14.
Soft Matter ; 15(27): 5511-5520, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31241632

RESUMO

Red blood cells in shear flow show a variety of different shapes due to the complex interplay between hydrodynamics and membrane elasticity. Malaria-infected red blood cells become generally adhesive and less deformable. Adhesion to a substrate leads to a reduction in shape variability and to a flipping motion of the non-spherical shapes during the mid-stage of infection. Here, we present a complete state diagram for wall adhesion of red blood cells in shear flow obtained by simulations, using a particle-based mesoscale hydrodynamics approach, multiparticle collision dynamics. We find that cell flipping at a substrate is replaced by crawling beyond a critical shear rate, which increases with both membrane stiffness and viscosity contrast between the cytosol and suspending medium. This change in cell dynamics resembles the transition between tumbling and tank-treading for red blood cells in free shear flow. In the context of malaria infections, the flipping-crawling transition would strongly increase the adhesive interactions with the vascular endothelium, but might be suppressed by the combined effect of increased elasticity and viscosity contrast.


Assuntos
Eritrócitos/citologia , Eritrócitos/fisiologia , Adesão Celular , Movimento Celular , Forma Celular , Simulação por Computador , Elasticidade , Membrana Eritrocítica/fisiologia , Cinética , Fenômenos Físicos , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Viscosidade
15.
Nutrients ; 11(6)2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31207887

RESUMO

Mature red blood cells (RBCs) not only account for ~83% of the total host cells in the human body, but they are also exposed to all body tissues during their circulation in the bloodstream. In addition, RBCs are devoid of de novo protein synthesis capacity and, as such, they represent a perfect model to investigate system-wide alterations of cellular metabolism in the context of aging and age-related oxidant stress without the confounding factor of gene expression. In the present study, we employed ultra-high-pressure liquid chromatography coupled with mass spectrometry (UHPLC-MS)-based metabolomics and proteomics to investigate RBC metabolism across age in male mice (6, 15, and 25 months old). We report that RBCs from aging mice face a progressive decline in the capacity to cope with oxidant stress through the glutathione/NADPH-dependent antioxidant systems. Oxidant stress to tryptophan and purines was accompanied by declines in late glycolysis and methyl-group donors, a potential compensatory mechanism to repair oxidatively damaged proteins. Moreover, heterochronic parabiosis experiments demonstrated that the young environment only partially rescued the alterations in one-carbon metabolism in old mice, although it had minimal to no impact on glutathione homeostasis, the pentose phosphate pathway, and oxidation of purines and tryptophan, which were instead aggravated in old heterochronic parabionts.


Assuntos
Envelhecimento , Eritrócitos , Metaboloma/fisiologia , Parabiose , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Animais , Proteínas Sanguíneas/análise , Proteínas Sanguíneas/metabolismo , Cromatografia Líquida de Alta Pressão , Eritrócitos/química , Eritrócitos/metabolismo , Eritrócitos/fisiologia , Masculino , Espectrometria de Massas , Redes e Vias Metabólicas/fisiologia , Metabolômica , Camundongos , Camundongos Endogâmicos C57BL , Proteoma/análise , Proteoma/fisiologia
16.
Nutr Hosp ; 36(4): 926-930, 2019 Aug 26.
Artigo em Espanhol | MEDLINE | ID: mdl-31192692

RESUMO

Introduction: Introduction: the situations of stress among which physical exercise is included imply the possibility of an excessive production of free radicals and, by their action, an oxidative stress in the cells. To combat these effects, cells have defense mechanisms called antioxidant systems. Objectives: the objective of this study is to analyze the possible physiological changes in relation to parameters related to oxidative stress (MDA) and antioxidant activity (vitamin A, vitamin C and vitamin E) in the erythrocytes of professional soccer players, in comparison with untrained subjects. Methods: forty-two men divided into 21 soccer players (SG) (24.95 ± 3.03 years) and 21 sedentary students (CG) (23.71 ± 2.42 years) participated in the study. Their basal levels of MDA, vitamin C, vitamin A and vitamin E in erythrocytes, as well as their anthropometric characteristics and VO2max, were evaluated. Results: significant differences were observed in the anthropometric characteristics (p < 0.05) and VO2max (p > 0.01). SG presented statistically lower levels of MDA (p > 0.01), vitamin C (p > 0.05), vitamin E (p > 0.05) and vitamin A (p > 0.01). Conclusions: there is higher oxidative stress in soccer players than in sedentary players and it may be necessary to supplement with antioxidants in this group.


Assuntos
Eritrócitos/fisiologia , Exercício/fisiologia , Estresse Oxidativo/fisiologia , Futebol/fisiologia , Adulto , Ácido Ascórbico/metabolismo , Estudos de Casos e Controles , Eritrócitos/metabolismo , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Comportamento Sedentário , Vitamina A/metabolismo , Vitamina E/metabolismo , Adulto Jovem
17.
Immunity ; 50(5): 1149-1162, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31117011

RESUMO

Nearly every tissue in the body undergoes routine turnover of cells as part of normal healthy living. The majority of these cells undergoing turnover die via apoptosis, and then are rapidly removed by phagocytes by the process of efferocytosis that is anti-inflammatory. However, a number of pathologies have recently been linked to defective clearance of apoptotic cells. Perturbed clearance arises for many reasons, including overwhelming of the clearance machinery, disruptions at different stages of efferocytosis, and responses of phagocytes during efferocytosis, all of which can alter the homeostatic tissue environment. This review covers linkages of molecules involved in the different phases of efferocytosis to disease pathologies that can arise due to their loss or altered function.


Assuntos
Apoptose/fisiologia , Eritrócitos/fisiologia , Fagócitos/metabolismo , Fagocitose/fisiologia , Homeostase , Humanos
18.
Naturwissenschaften ; 106(5-6): 24, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31069520

RESUMO

Acclimation to lower temperatures decreases energy expenditure in ectotherms but increases oxygen consumption in most endotherms, when dropped below thermoneutrality. Such differences should be met by adjustments in oxygen transport through blood. Changes in hematological variables in correspondence to that in metabolic rates are, however, not fully understood, particularly in non-avian reptiles. We investigated the effect of thermal acclimation on a snake model, the grass snakes (Natrix natrix). After 6 months of acclimation to either 18 °C or 32 °C hematocrit, hemoglobin concentration, erythrocyte number, and size were assessed. All variables revealed significantly lower values under warm compared to cold ambient temperature. Our data suggest that non-avian reptiles, similarly as birds, reduce erythrocyte fraction under energy-demanding temperatures. Due to low deformability of nucleated erythrocytes in sauropsids, such reduced fraction may be important in decreasing blood viscosity to optimize blood flow. Novel findings on flexible erythrocyte size provide an important contribution to this optimization process.


Assuntos
Aclimatação/fisiologia , Temperatura Baixa , Eritrócitos/fisiologia , Serpentes/fisiologia , Animais , Tamanho Celular , Contagem de Eritrócitos , Hematócrito , Hemoglobinas , Temperatura Alta
19.
Vox Sang ; 114(6): 535-552, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31090093

RESUMO

The ABH and Lewis antigens were among the first of the human red blood cell polymorphisms to be identified and, in the case of the former, play a dominant role in transfusion and transplantation. But these two therapies are largely twentieth-century innovations, and the ABH and related carbohydrate antigens are not only expressed on a very wide range of human tissues, but were present in primates long before modern humans evolved. Although we have learned a great deal about the biochemistry and genetics of these structures, the biological roles that they play in human health and disease are incompletely understood. This review and its companion, which appeared in a previous issue of Vox Sanguinis, will focus on a few of the biologic and pathologic processes which appear to be affected by histo-blood group phenotype. The first of the two reviews explored the interactions of two bacteria with the ABH and Lewis glycoconjugates of their human host cells, and described the possible connections between the immune response of the human host to infection and the development of the AB-isoagglutinins. This second review will describe the relationship between ABO phenotype and thromboembolic disease, cardiovascular disease states, and general metabolism.


Assuntos
Sistema do Grupo Sanguíneo ABO , Doenças Cardiovasculares , Trombose , Eritrócitos/imunologia , Eritrócitos/fisiologia , Humanos
20.
mBio ; 10(3)2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138740

RESUMO

Cerebral malaria is a severe neurological complication associated with sequestration of Plasmodium falciparum-infected erythrocytes (IE) in the brain microvasculature, but the specific binding interactions remain under debate. Here, we have generated an engineered three-dimensional (3D) human brain endothelial microvessel model and studied P. falciparum binding under the large range of physiological flow velocities that occur in both health and disease. Perfusion assays on 3D microvessels reveal previously unappreciated phenotypic heterogeneity in parasite binding to tumor necrosis factor alpha (TNF-α)-activated brain endothelial cells. While clonal parasite lines expressing a group B P. falciparum erythrocyte membrane protein 1 (PfEMP1) present an increase in binding to activated 3D microvessels, P. falciparum -IE expressing DC8-PfEMP1 present a decrease in binding. The differential response to endothelium activation is mediated by surface expression changes of endothelial protein C receptor (EPCR) and intercellular adhesion molecule 1 (ICAM-1). These findings demonstrate heterogeneity in parasite binding and provide evidence for a parasite strategy to adapt to a changing microvascular environment during infection. The engineered 3D human brain microvessel model provides new mechanistic insight into parasite binding and opens opportunities for further studies on malaria pathogenesis and parasite-vessel interactions.IMPORTANCE Cerebral malaria research has been hindered by the inaccessibility of the brain. Here, we have developed an engineered 3D human brain microvessel model that mimics the blood flow rates and architecture of small blood vessels to study how P. falciparum -infected human erythrocytes attach to brain endothelial cells. By studying parasite lines with different adhesive properties, we show that the malaria parasite binding rate is heterogeneous and strongly influenced by physiological differences in flow and whether the endothelium has been previously activated by TNF-α, a proinflammatory cytokine that is linked to malaria disease severity. We also show the importance of human EPCR and ICAM-1 in parasite binding. Our model sheds new light on how P. falciparum binds within brain microvessels and provides a powerful method for future investigations of recruitment of human brain pathogens to the blood vessel lining of the brain.


Assuntos
Encéfalo/parasitologia , Adesão Celular , Receptor de Proteína C Endotelial/metabolismo , Eritrócitos/parasitologia , Molécula 1 de Adesão Intercelular/metabolismo , Microvasos/parasitologia , Plasmodium falciparum/fisiologia , Sítios de Ligação , Encéfalo/citologia , Técnicas de Cultura de Células , Células Cultivadas , Células Endoteliais/parasitologia , Receptor de Proteína C Endotelial/genética , Eritrócitos/fisiologia , Humanos , Molécula 1 de Adesão Intercelular/genética , Malária Cerebral/parasitologia , Malária Cerebral/fisiopatologia , Malária Falciparum/parasitologia , Microvasos/citologia , Proteínas de Protozoários/metabolismo , Receptores de Superfície Celular/metabolismo , Engenharia Tecidual/métodos , Fator de Necrose Tumoral alfa/imunologia
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