Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Int J Radiat Biol ; 93(12): 1306-1311, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29034757

RESUMEN

PURPOSE: Storage and ionizing radiation of human red blood cells (RBC) produce alterations on RBC membranes and modify their normal shape and functionality. We investigated early morphological and biochemical changes in RBC due to those stressing agents at the nanoscale level and their impact on blood quality. MATERIALS AND METHODS: Whole blood samples from healthy donors were γ-irradiated with 15, 25, 35, and 50 Gy. Non-irradiated and non-stored RBC were used as control samples. Irradiated blood samples were stored separately at 4 °C and analyzed immediately and after 5 and 13 d. Atomic force microscopy (AFM), osmotic fragility and Raman spectroscopy were used to detect morphological and biochemical changes. RESULTS: RBC function is challenged by both irradiation and storage. The storage procedure caused nanometric variations over the surface of RBC membrane for both irradiated and non-irradiated cells. The membrane of RBC became more fragile, while the biochemical fingerprint of hemoglobin (Hb) remained unaltered. CONCLUSIONS: Our work shows that the irradiation procedure leads to an increase in the number and size of nanovesicles along with the dose. The functionality of RBC can be affected from changes in the roughness, becoming more fragile and susceptible to breakage.


Asunto(s)
Membrana Eritrocítica/efectos de la radiación , Rayos gamma/efectos adversos , Nanotecnología , Adulto , Humanos , Fragilidad Osmótica/efectos de la radiación , Adulto Joven
2.
Int J Radiat Biol ; 90(12): 1201-10, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24369823

RESUMEN

PURPOSE: To investigate the extent of γ-irradiation-induced oxidative membrane damage and antioxidant activity of quercetin in long-term, cold stored (4°C) acid-citrate-dextrose- preserved human red blood cells (RBC). MATERIALS AND METHODS: The extracellular activity of lactate dehydrogenase (LDH) was measured to assess RBC membrane integrity. Lipid peroxidation and reduced glutathione (GSH) levels were quantified by thiobarbituric acid-reactive substances (TBARS) and Ellman's reagent, respectively. RESULTS: During storage of non-irradiated RBC (up 21 days) the LDH activity in the supernatant increased with time. In contrast to a low dose of ionizing radiation (30 Gy), irradiation at higher, but still clinically relevant doses, of 40-50 Gy resulted in elevation of the post-storage extracellular LDH activity. Quercetin (2-50 µM) dissolved in dimethyl sulfoxide (DMSO) significantly increased the LDH release in the irradiated and non-irradiated RBC, reflecting an increase of RBC membrane permeability. In the presence of ethanol as a solvent quercetin protected RBC against storage-induced oxidative damage - it inhibited the LDH release, GSH depletion, and lipid peroxidation. CONCLUSION: The level of protection offered by quercetin against the radiation- and storage-induced oxidative damage to RBC does not seem to be sufficient to warrant its application as an additive for conservation purposes. The findings indicate that the solvent can modulate a response of RBC to water-insoluble antioxidants changing their properties from anti-oxidative to pro-oxidative.


Asunto(s)
Citoprotección/efectos de los fármacos , Transfusión de Eritrocitos , Eritrocitos/metabolismo , Rayos gamma/efectos adversos , Estrés Oxidativo/efectos de los fármacos , Quercetina/farmacología , Manejo de Especímenes , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta en la Radiación , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Eritrocitos/efectos de la radiación , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/metabolismo , Espacio Extracelular/efectos de la radiación , Glutatión/metabolismo , Humanos , L-Lactato Deshidrogenasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Peroxidación de Lípido/efectos de la radiación , Fragilidad Osmótica/efectos de los fármacos , Fragilidad Osmótica/efectos de la radiación , Estrés Oxidativo/efectos de la radiación , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo
3.
Radiat Environ Biophys ; 50(1): 189-98, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20865271

RESUMEN

It is believed that any dose of ionizing radiation may damage cells and that the mutated cells could develop into cancer cells. Additionally, results of research performed over the past century on the effects of low doses of ionizing radiation on biological organisms show beneficial health effects, called hormesis. Much less is known about the cellular response to low doses of ionizing radiation, such as those typical for medical diagnostic procedures, normal occupational exposures or cosmic-ray exposures at flight altitudes. Extrapolating from the effects observed at higher doses to predict changes in cells after low-dose exposure is problematic. We examined the biological effects of low doses (0.01-0.3 Gy) of γ-radiation on the membrane characteristics of erythrocytes of albino rats and carried out osmotic fragility tests and Fourier transform infrared spectroscopy (FTIR). Our results indicate that the lowest three doses in the investigated radiation range, i.e., 0.01, 0.025 and 0.05 Gy, resulted in positive effects on the erythrocyte membranes, while a dose of 0.1 Gy appeared to represent the limiting threshold dose of those positive effects. Doses higher than 0.1 Gy were associated with the denaturation of erythrocyte proteins.


Asunto(s)
Membrana Eritrocítica/efectos de la radiación , Rayos gamma , Animales , Relación Dosis-Respuesta a Droga , Membrana Eritrocítica/metabolismo , Femenino , Soluciones Hipotónicas , Masculino , Fragilidad Osmótica/efectos de la radiación , Ratas , Ratas Wistar , Espectroscopía Infrarroja por Transformada de Fourier
4.
Ann Ist Super Sanita ; 43(2): 176-85, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17634667

RESUMEN

The irradiation of blood components with X or gamma rays is necessary to prevent the graft-versus-host disease, but it also provokes untoward effects. In particular, red cells are damaged and have a decreased in vivo recovery, an increased in vitro haemolysis, and a leakage of potassium in the supernatant. The results of the clinical studies show that the loss of viability progressively increases with the storage after irradiation. On the other hand, the storage before irradiation is inconsequential. The mechanism through which irradiation causes the loss of viability is unknown, but a critical examination of the literature and our results indicate that the erythrocyte deformability is the only parameter related to viability to show sufficiently precocious and important changes. We also tried to identify the mechanism by which irradiation influences deformability and examined, in particular, the changes in the mean cell volume (MCV) and vesiculation. However, the temporal behaviour of both suggests no causal relationship.


Asunto(s)
Deformación Eritrocítica/fisiología , Deformación Eritrocítica/efectos de la radiación , Eritrocitos/fisiología , Eritrocitos/efectos de la radiación , Adenosina Trifosfato/sangre , Supervivencia Celular/efectos de la radiación , Hemólisis/efectos de la radiación , Hemorreología , Humanos , Fragilidad Osmótica/efectos de la radiación
5.
Artículo en Ruso | MEDLINE | ID: mdl-12945135

RESUMEN

Modification of erythrocytic membrane and the trend in clinicofunctional indices were studied in 93 patients with angina of effort (FC i-IV) in the course of treatment with laser radiation (group 1) and imitation of laser radiation (group 2). In patients of group 1 the treatment resulted in stabilization of cell membrane accompanied with positive cardiodynamic changes.


Asunto(s)
Peroxidación de Lípido/efectos de la radiación , Terapia por Luz de Baja Intensidad , Contracción Miocárdica/efectos de la radiación , Isquemia Miocárdica/radioterapia , Membrana Eritrocítica/metabolismo , Humanos , Peroxidación de Lípido/fisiología , Peróxidos Lipídicos/sangre , Masculino , Contracción Miocárdica/fisiología , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/fisiopatología , Fragilidad Osmótica/efectos de la radiación , Función Ventricular Izquierda/fisiología , Función Ventricular Izquierda/efectos de la radiación
6.
Blood Cells Mol Dis ; 24(3): 385-95; discussion 396-8, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10087995

RESUMEN

A study on blood cell damage after irradiation of fresh whole blood with 630 nm laser light was carried out in vitro. Various fluence rates of laser light were used with and without cooling of blood. Damage to the blood was assessed by blood cell counts, osmotic fragility measurements and examination of blood films. Exposure of a 1 mm blood layer to 630 nm laser light without cooling led to changes in blood counts first detected at fluence rates of 130 mW/cm2. Changes in osmotic fragility first became evident at 210 mW/cm2. Increasing cell damage with increasing fluence rates was evident in blood films. Using the cooling device changes in whole blood after irradiation first occurred at a fluence rate of 293 mW/cm2. Measurement of the fluence rates at which cell damage begins is important in laser induced fluorescence diagnostics and photodynamic therapy applications in blood or blood products using photosensitizers.


Asunto(s)
Células Sanguíneas/efectos de la radiación , Rayos Láser/efectos adversos , Adulto , Recuento de Células Sanguíneas/efectos de la radiación , Células Sanguíneas/patología , Núcleo Celular/efectos de la radiación , Núcleo Celular/ultraestructura , Hemoglobinas/efectos de la radiación , Hemólisis/efectos de la radiación , Humanos , Masculino , Fragilidad Osmótica/efectos de la radiación , Fotoquímica , Fotoquimioterapia , Tolerancia a Radiación , Espectrina/efectos de la radiación , Temperatura
7.
Biull Eksp Biol Med ; 116(10): 428-30, 1993 Oct.
Artículo en Ruso | MEDLINE | ID: mdl-8117976

RESUMEN

An investigation of blood rheologic properties in 12 patients with acute pneumonia has been made by using low-energy He-Ne laser (LG-79-2) irradiation of vascular fascicle. 37 exposures have been performed, 40 min each. Immediate effects of He-Ne laser were studied comparing blood samples taken before and after the radiation. Results obtained have demonstrated transcutaneous blood irradiation causing prompt and pronounced effects on blood rheologic characteristics: reduced blood viscosity, improved both viscous-elastic properties and osmotic resistance of erythrocytes, activated platelet aggregation. These effects excluding the latter are rather positive for the human body. As for platelet aggregation, its activation following transcutaneous laser irradiation of blood might be expected to grow into a factor of risk provoking pathologic thrombogenesis in venous congestion, hypercoagulation and vascular wall injury.


Asunto(s)
Viscosidad Sanguínea/efectos de la radiación , Codo/irrigación sanguínea , Terapia por Láser , Enfermedad Aguda , Codo/efectos de la radiación , Humanos , Fragilidad Osmótica/efectos de la radiación , Agregación Plaquetaria/efectos de la radiación , Neumonía/sangre , Neumonía/radioterapia , Factores de Tiempo
8.
Radiobiologiia ; 33(2): 302-6, 1993.
Artículo en Ruso | MEDLINE | ID: mdl-8502752

RESUMEN

The influence of incorporated cesium 137 (the absorbed doses of 0.26-0.08 Gy) on the erythrocyte membrane structure has been investigated. It has been shown that chronic internal exposure to gamma radiation causes structural reorganization of erythrocyte membranes at remote postirradiation times (in 3 and 6 months) that influences the annular membrane lipid.


Asunto(s)
Radioisótopos de Cesio/farmacología , Membrana Eritrocítica/efectos de la radiación , Animales , Radioisótopos de Cesio/sangre , Membrana Eritrocítica/metabolismo , Membrana Eritrocítica/ultraestructura , Colorantes Fluorescentes , Rayos gamma , Masculino , Lípidos de la Membrana/efectos de la radiación , Fragilidad Osmótica/efectos de la radiación , Ratas , Factores de Tiempo
10.
Int J Biochem ; 22(1): 25-30, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2328818

RESUMEN

1. Oxidative stress by phenazine methosulfate stimulated proteolysis in erythrocytes. 2. Gamma-irradiation of erythrocytes in the range of 50-1000 Gy also resulted in the induction of proteolysis. 3. Though it has been suggested that hyperthermia imposes an oxidative stress on a cell, hyperthermic exposure of erythrocytes (30 min, 39-49 degrees C) did not stimulate proteolysis during subsequent incubation of whole cells or hemolysates. 4. Proteolytic degradation of spectrin was accelerated during incubation of membranes isolated from cells heated above 45 degrees C but this effect seems to be due rather to thermal denaturation of spectrin than to oxidative modification of cellular proteins by hyperthermia.


Asunto(s)
Eritrocitos/metabolismo , Calor , Proteínas de la Membrana/metabolismo , Aminoácidos/análisis , Células Cultivadas , Relación Dosis-Respuesta en la Radiación , Eritrocitos/efectos de los fármacos , Eritrocitos/efectos de la radiación , Rayos gamma , Hemólisis , Humanos , Metosulfato de Metilfenazonio/farmacología , Modelos Biológicos , Fragilidad Osmótica/efectos de los fármacos , Fragilidad Osmótica/efectos de la radiación , Espectrina/metabolismo
11.
Lab Delo ; (7): 29-31, 1990.
Artículo en Ruso | MEDLINE | ID: mdl-1699063

RESUMEN

Measurements of red cell osmotic resistance in urea test have shown the stabilizing effect of hydrocortisone and ascorbic acid on red cell membrane permeability. This permitted a conclusion on the fitness of the test for assessment of the drug effects on red cell membrane permeability and on the possibility of the use of this test in choosing an individual dose of UV irradiation.


Asunto(s)
Fragilidad Osmótica , Ácido Ascórbico/farmacología , Humanos , Hialuronoglucosaminidasa/farmacología , Hidrocortisona/farmacología , Técnicas In Vitro , Fragilidad Osmótica/efectos de los fármacos , Fragilidad Osmótica/efectos de la radiación , Rayos Ultravioleta
13.
Biochimie ; 68(2): 311-8, 1986 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3089322

RESUMEN

The effects of whole-body gamma-irradiation of rats (8 Gy) on erythrocyte enzymes and biochemical components involved in lipid peroxidation were studied. Decreased superoxide dismutase and glutathione reductase activities, and lowered concentrations of reduced glutathione, were found to be the main factors responsible for the observed increase in lipid peroxidation in the erythrocytes of irradiated rats. This increased lipid peroxidation did not result in a greater tendency to hemolysis in hypotonic media; on the contrary, the mean osmotic fragility was decreased at days D + 1 and D + 3 after irradiation. The behavior of the erythrocyte populations towards hemolysis in hypotonic media appeared to be most homogeneous at days D + 4 and D + 8 after irradiation, which correspond to maxima of malonic dialdehyde concentrations in erythrocytes. Such a synchrony of variations suggests that crosslinking of primary amino groups of proteins or phospholipids by malonic dialdehyde might produce a rigidification in erythrocyte membranes, possibly leading to a more homogeneous behavior of the erythrocyte populations towards hemolysis in hypotonic media.


Asunto(s)
Eritrocitos/efectos de la radiación , Peróxidos Lipídicos/sangre , Animales , Catalasa/sangre , Eritrocitos/fisiología , Rayos gamma , Glutatión Peroxidasa/sangre , Peróxidos Lipídicos/efectos de la radiación , Fragilidad Osmótica/efectos de la radiación , Ratas , Superóxido Dismutasa/genética , Irradiación Corporal Total
14.
Farmakol Toksikol ; 48(2): 72-7, 1985.
Artículo en Ruso | MEDLINE | ID: mdl-3158539

RESUMEN

Experiments with phospholipid liposomes, red cells (or their shades) of man and pigeon, modulated with helium-neon laser, were made to study the effects of papaverine, verapamil, phosphadene, theophylline, nicotinic acid, acetylcholine, adenosine and hydralazine on the intensity of the own fluorescence of the membrane and of the membrane-bound probe, 1,8-AHC, segregation of methylene blue by the red cell mass, red cell resistance to osmotic or UV-induced hemolysis as well as on the activity of Na-, K-, Mg- and Ca-dependent ATPases of the red cell shades of the donor or pigeon. As regards the tests used, the most differentiated membranous effects were discovered for the drugs under study within the concentration range 10(-5)-10(-8) M. The vasoactive agents administered at equimolar end concentrations produced quantitatively and qualitatively inconsistent effects on the parameters tested. They increased (with the exception of acetylcholine) segregation of the cationic dye, reduced the fluorescence intensity of the probe, and elevated the resistance to osmotic and UV-induced hemolysis. The latter circumstance is likely to be determined by activation of membranous ATPases. Exposure to laser potentiated the membrane-stabilizing action of the substances under consideration.


Asunto(s)
Membrana Eritrocítica/efectos de los fármacos , Lípidos de la Membrana/farmacología , Fosfolípidos/farmacología , Vasodilatadores/farmacología , Adenosina Trifosfatasas/sangre , Animales , Embrión de Pollo , Columbidae , Interacciones Farmacológicas , Membrana Eritrocítica/enzimología , Membrana Eritrocítica/efectos de la radiación , Fluorescencia , Hemólisis/efectos de los fármacos , Hemólisis/efectos de la radiación , Humanos , Liposomas/farmacología , Lípidos de la Membrana/efectos de la radiación , Fragilidad Osmótica/efectos de los fármacos , Fragilidad Osmótica/efectos de la radiación , Fosfolípidos/efectos de la radiación , Rayos Ultravioleta
16.
Acta Paediatr Scand ; 73(2): 254-7, 1984 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6741524

RESUMEN

In order to determine the in vivo effect of phototherapy on the erythrocytes' osmotic fragility, we have tested 10 preterm infants treated by continuous phototherapy, for jaundice of prematurity. Heparinized blood was obtained daily, starting before the initiation of phototherapy and ending 24 h after stopping the treatment. The osmotic fragility was tested in duplicate immediately, after 1 h incubation at 40 degrees C and after 24 h incubation at 4 degrees C in darkness. The erythrocytes of the preterm infant during and at the end of phototherapy showed a normal osmotic fragility pattern. Comparing the consecutive curves in each infant did not show any population of osmotically differing erythrocytes. Heating or cooling the erythrocytes did not alter these results. It is concluded that phototherapy does not increase the in vivo osmotic fragility of erythrocytes in newborn.


Asunto(s)
Enfermedades del Prematuro/terapia , Ictericia Neonatal/terapia , Fragilidad Osmótica/efectos de la radiación , Fototerapia , Femenino , Humanos , Recién Nacido , Enfermedades del Prematuro/sangre , Ictericia Neonatal/sangre , Masculino
18.
Artículo en Inglés | MEDLINE | ID: mdl-6600734

RESUMEN

Irradiated porcine erythrocytes demonstrated increased osmotic fragility, which was enhanced by the addition of anions. The extent of the damage produced by the secondary radicals depended on the kind of anion and conditions of irradiation. The most pronounced changes occurred in the presence of azide, whereas bromide and thiocyanate gave rise to a smaller enhancement of osmotic fragility. Irradiation of cells in air or N2O revealed that radical anions have more damaging effects on porcine erythrocytes in air.


Asunto(s)
Azidas/farmacología , Membrana Eritrocítica/efectos de la radiación , Eritrocitos/efectos de la radiación , Animales , Bromuros/farmacología , Membrana Eritrocítica/efectos de los fármacos , Radicales Libres , Rayos gamma , Fragilidad Osmótica/efectos de los fármacos , Fragilidad Osmótica/efectos de la radiación , Oxígeno , Porcinos , Tiocianatos/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...