Effects of acute low doses of gamma-radiation on erythrocytes membrane.

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.

Deformability and viability of irradiated red cells.

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.

Nano alterations of membrane structure on both γ-irradiated and stored human erythrocytes.

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.

Influence of whole-body gamma-irradiation upon rat erythrocyte: lipid peroxidation and osmotic fragility.

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.

[Efficacy of laser therapy in patients with ischemic heart disease]. / Effektivnost' lazeroterapii bol'nykh ishemicheskoi bolezn'iu serdtsa.

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.

A moderate protective effect of quercetin against γ-irradiation- and storage-induced oxidative damage in red blood cells for transfusion.

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.

Osmotic fragility of erythrocytes in newborn infants treated by phototherapy.

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.

Increased osmotic fragility of erythrocytes in chronically jaundiced rats after phototherapy.

Littermate homozygous (jj) and heterozygous (Jj) Gunn rats, were irradiated with blue fluorescent light for 18 hours continuously. The incident irradiance was 1.5 mWatts/cm2 in the 420--480 nm band pass. The influence of the irradiance on circulating erthrocytes was studied by testing their osmotic fragility before and after the irradiance. The non-jaundiced, Jj, animals did not exhibit any increase in the osmotic fragility of their erythrocytes. The osmotic fragility of the erythrocytes from jaundiced, jj, animals was the same as the Jj animals prior irradiance. However, the fragility of the erythrocytes from the jj animals was significantly increased after the 18 hours of irradiance. The results indicated that the photodynamic action of bilirubin may be present in vivo.

[Changes in the blood rheological properties in the transcutaneous irradiation of the ulnar vascular fascicle with a helium-neon laser]. / Izmenenie reologicheskikh svoistv krovi pri chreskozhnom obluchenii loktevogo sosudistogo puchka gelii-neonovym lazerom.

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.

[The effect of several factors on the osmotic resistance of erythrocytes]. / Vliianie nekotorykh vozdeistvii na osmoticheskuiu stoikost' éritrotsitov.

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.

[Effect of super-high electromagnetic radiation and hormones on the osmotic resistance of mouse erythrocytes]. / Vliianie élektromagnitnogo izlucheniia sverkhvysokochastnogo diapazona i nekotorykh gormonov na osmoticheskuiu rezistentnost' éritrotsitov myshei.

Hydrocortisone, adrenaline and corticotrophin prevent osmotic alterations in red cell resistance and increase the survival of mice when injected every other day during the whole period of microwave irradiation (62 +/- 5 mv/cm2, 2375 MHz, 8 min daily for 12 days).

Effect of UV-irradiation in vitro on adenin nucleotides metabolism, Na+ and K+ concentration, osmotic properties and submicroscopic structure of pigeon red blood cells.

Effect of UV-irradiation in vitro on metabolism of adenine nucleotides: ADP, ATP and AXP, osmotic properties and submicroscopic structure of nucleated pigeon red blood cell was investigated. Irradiation carried out for 60, 120, 180, 240 and 300 minutes. Hanau S-500 lamp with efficiency 4.34-10(8) erh/sec was used. A decrease of ATP content with a stimultaneous increase of ADP and AXP contents and a rather constant level of the sum of adenine compounds was observed. UV-irradiation caused a decrease of reversal of hemolysis and osmotic resistance to hypotonic NaCl solutions. An equivalent exchange of Na+ and K+ ion and an increase of hematocrit value, following UV-irradiation was observed. Electron microscope studies demonstrated changes of ultrastructure concerning both cell nucleus and thickness and granulation of cell membrane.

Blood cell damage after in vitro irradiation of fresh whole blood with 630 nm laser light.

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.

[The effect of incorporated cesium-137 on the structure of the erythrocyte membranes]. / Vliianie inkorporirovannogo tseziia-137 na strukturnoe sostoianie mebran éritrotsitov.

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.