Longitudinal changes in red blood cell distribution width decades after radiation exposure in atomic-bomb survivors.

Red blood cell distribution width (RDW), which generally increases with age, is a risk marker for morbidity and mortality in various diseases. We investigated the association between elevated RDW and prior radiation exposure by examining longitudinal RDW changes in 4204 atomic-bomb survivors over 15 years. A positive association was found between RDW and radiation dose, wherein RDW increased by 0·18%/Gy. This radiation-associated effect increased as the participants aged. Elevated RDW was also associated with higher all-cause mortality. The biological mechanisms underlying these observed associations merit further investigation.

Protective role of Spirulina platensis against UVA-induced haemato-biochemical and cellular alterations in Clarias gariepinus.

Recently, it has become widely recognized that ultraviolet A (UVA) exposure is harmful for both aquatic and terrestrial organisms. Many studies have reported the effects of UVA on aquatic animals, especially fish, but little is known about the antioxidant role of microalgae in ameliorating the negative effects of UVA exposure. Recently, there has been great interest in using Spirulina platensis (SP) as a dietary antioxidant agent. Therefore, this study aimed to investigate the protective role of SP against UVA-induced effects by analysing haemato-biochemical alterations and erythrocyte cytotoxic and genotoxic biomarkers in African catfish (Clarias gariepinus). Fish were exposed to UVA, UVA + 100 mg/L SP extract, UVA + 200 mg/L SP extract for 3 days (UVA exposure: 1 h/day), and were not subjected to treatment (control group). The results showed the presence of some morphological malformations in red blood cells (RBCs) after UVA exposure. Additionally, nuclear abnormalities, including micronuclei, were observed. UVA induced alterations in most of the haemato-biochemical indices. Adding SP to the fish aquaria restored the haemato-biochemical parameters to their control values. In addition, SP repaired cellular damage in a dose-dependent manner. We conclude that SP plays a modulatory role in preventing and/or repairing the haemotoxic effects induced by UVA.

The effects of gamma-radiation on red blood cell corpuscles and dimensional properties in rats.

In an attempt to understand the toxicity and the potential role of gamma-radiation as a therapeutic tool, the effects of different Gamma-radiation doses on haematological and dimensional properties of rats' blood were investigated in vivo. 60 healthy male Wistar-Kyoto rats were used, which were randomly divided into five groups, 4 Gamma-radiated rat groups (1st group was radiated with five Gamma-radiation dose, 2nd group 25 Gy; 3rd group with 50 Gy, 4th group with 100 Gy, and 5th group was control). Different haematological and dimensional parameters were measured using the standard haematological technique. A significant decrease in red blood cells (RBCs) count, haemoglobin (HGB), and haematocrit (HCT) was observed compared with the control. While a significant increase in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC), red distribution width (RDW) were observed compared with the control. This study suggested that low RBCs, HGB, and HCT might produce anemia and cessation of erythrocytes production in the bone marrow. Moreover, the RBCs size increase might be attributed to changes in the morphology and deformability of RBCs, which was confirmed by a slightly increase in RDW.

A prospective dosimetric and clinical comparison of acute hematological toxicities in three-dimensional conformal radiation therapy and intensity modulated radiation therapy with concurrent chemotherapy in carcinoma cervix.

BACKGROUND AND OBJECTIVES: Acute hematological toxicities are an important cause of morbidity in patients receiving concurrent chemoradiation to pelvis in carcinoma cervix. The objective of this study was to evaluate the role of intensity-modulated radiotherapy (IMRT) in reducing the dose to the bone marrow as compared with three-dimensional conformal radiotherapy (3DCRT) and hence its impact on reducing the acute hematological toxicities. MATERIALS AND METHODS: Eleven consecutive patients treated with IMRT and 12 patients treated with 3DCRT to the whole pelvis along with concurrent chemotherapy were selected. Bone marrow was delineated. V10 Gy, V20 Gy, V95%, and Dmean of bone marrow were recorded. Weekly blood counts were recorded and graded as per Common Terminology Criteria version 4.0 for all the patients. RESULTS: The dose to the bone marrow V20 Gy was 206.78 ± 57.10 cc (75%) and 251.70 ± 40.45 cc (91%) for IMRT and 3DCRT, respectively (P = 0.04) and V95% was 23.30 ± 8.34% and 46.76 ± 6.71% for IMRT and 3DCRT, respectively (P = 0.001). The grade of toxicities during each week did not show the difference in either arm. However, the total count and Neutrophil counts during the 2nd week showed statistical significance between IMRT and 3DCRT. CONCLUSION: IMRT significantly reduces the dose to the bone marrow as compared to 3DCRT. The reduction of the dose did not translate into a decrease in acute hematological toxicities. Concurrent platinum-based chemotherapy is the probable cause for the hematological toxicities.

A simulation study on photoacoustic signals from red blood cells.

A two dimensional simulation study was performed to investigate the photoacoustic signal properties of non-aggregated and aggregated erythrocytes. Spatial distributions of non-aggregated blood samples were generated by employing a Monte Carlo method and aggregated blood samples were simulated using a hexagonal packing scheme. For the non-aggregating case photoacoustic signals demonstrated a monotonic rise with hematocrit. For the aggregating case it was found that spectral (<20 MHz) intensity increased (11 dB at 15.6 MHz) when the aggregate size increased. This study strongly suggests that the assessment of erythrocyte aggregation level in human blood might be possible by using a photoacoustic spectroscopic method.

Influence of irradiation on in vitro red-blood-cell (RBC) storage variables of leucoreduced RBCs in additive solution PAGGS-M.

BACKGROUND: The effect of gamma irradiation on leucoreduced red-blood-cells (RBCs) stored in an additive solution (AS) containing phosphate, adenine, glucose, guanosine, saline and mannitol (PAGGS-M) has not yet been studied, and there are different recommendations about storage time of leucoreduced RBCs after irradiation. STUDY DESIGN AND METHODS: We studied 63 leucoreduced RBC units. All RBCs were stored in AS PAGGS-M and leucoreduced on the collection day. Twenty-one components were irradiated on Day +14 with 30 Gy and 22 served as non-irradiated controls. Samples were drawn and analysed from these 43 units on Day +7, +14, +21, +28, +35, +42 and +49 from the collection day. From 20 units, no samples were taken earlier than on Day +49. Of these, 10 components had been irradiated on Day +14 with 30 Gy and 10 served as non-irradiated controls. RESULTS: Gamma irradiation induced an enhanced in vitro haemolysis rate in the irradiated components. One of the irradiated units showed a haemolysis rate over the recommended limit of 0·8% on Day +42 and four on Day +49. The leakage of potassium ions from irradiated RBCs started to increase faster than that of unirradiated RBCs from the day of irradiation. Lactate dehydrogenase levels increased faster in irradiated units 3 weeks after irradiation. We showed that taking samples weekly does not affect the final result. CONCLUSIONS: Our findings show that the European recommendations should not be changed in regard to the limitation of the storageability after irradiation of leucoreduced RBCs. The damage after irradiation and storage cannot be prevented by using the high-quality AS PAGGS-M.

The effects of irradiation on the blood dynamics.

AIM: The present study evaluates the effects of irradiation on the blood dynamics. MATERIALS AND METHODS: Thirty-six volunteers providing written consent participated. A blood sample was transferred into three tubes containing CPDA-1 solution while another blood sample was transferred into three tubes containing heparin. Each tube containing CPDA-1 solution was paired with another tube containing heparin. The first pair was not irradiated, not stored and analyzed immediately (Group 1). The second pair was not irradiated, stored and analyzed at seven days (Group 2). The third pair was irradiated, stored and analyzed at seven days (Group 3). The blood count was performed and the blood viscosity was determined. RESULTS: The mean hemoglobin contents were 126 g/l for Group 1, 128 g/l for Group 2 and 129 g/l for Group 3. For the mean hemoglobin contents, the difference between Group 1 and Group 3 (P<0.001) and Group 2 and Group 3 (P=0.01) were significant. The mean red blood cell volumes were 81.8 fl for Group 1, 82.1 fl for Group 2 and 82.3 fl for Group 3. For the mean red blood cell volumes, the difference between Group 1 and Group 2 (P=0.003) and Group 1 and Group 3 (P=0.006) were significant. The mean blood viscosities were 2.2 mPa s for Group 1, 2.8 mPa s for Group 2 and 3.2 mPa s for Group 3. For the mean blood viscosities, the difference between Group 1 and Group 2 (P<0.001), Group 1 and Group 3 (P<0.001) and Group 2 and Group 3 (P=0.004) were significant. CONCLUSION: The present study indicates that the recommended doses of irradiation for the blood products to be used in attempt to prevent the transfusion associated graft versus host disease leads to marked alterations in the blood dynamics and might decrease the viability of the red blood cells following transfusion.

Effect of irradiation on red cell cation content and transport.

The effect of irradiation on red cell (RBC) cation content and membrane transport was studied. When units of RBCs collected in AS-1 (n = 8) were exposed to radiation (2000 cGy) and then stored at 4 degrees C, there was a significant increase in external K and internal Na and a decrease in internal K relative to control units (n = 3). Similar changes in internal cation contents were noted for RBCs collected in CPD; because of the higher hematocrit, the external K concentration was higher than that in AS-1-collected RBCs. Cellular K loss and Na gain were balanced, and the total cation content remained constant; however, both control and irradiated cells swelled over time as a consequence of the decreased pH and 2.3 DPG content. These changes in volume and cation content were reversed when the cells were incubated at 37 degrees C. A specific effect of radiation on the Na-K pump and Na-K-Cl and K-Cl cotransport systems was ruled out, because no significant differences between irradiated cells and controls were found. These data indicate that radiation induces an increased permeability to Na and K on the part of the RBC membrane lipid bilayer and that this increase is balanced and reversible.

The elevation of blood levels of zinc protoporphyrin in mice following whole body irradiation.

Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. We have discovered that sublethal doses of whole body irradiation with x-rays also elevates ZPP 2-3-fold over normal levels. The ZPP level does not begin to increase until days 12-14 postirradiation and peaks between days 18 and 20 before returning to normal levels between days 28 and 35. Increasing the radiation dose delays the onset of the rise in ZPP, but does not affect the magnitude of the elevation. At lethal doses, ZPP elevation is not observed. Neither of the two previously described mechanisms that cause elevations of ZPP, namely iron deficiency and inhibition of ferrochelatase, are responsible for the radiation-induced elevation of ZPP. The elevation of ZPP appears to be correlated with the recovery of the hematopoietic system from radiation injury.

[State of erythrocytes after long-term exposure to magnetic field]. / Sostoianie eritrotsitov pri dlitel'nom vozdeistvii magnitnogo polia.

During and after exposure to a constant magnetic field of 1.6 T mice, showed variations in the size distribution of red blood cells, with their shape remaining unchanged and enlarged cells being predominant. This shift persisted till exposure day 10 and began to return to normal on days 15, 22 and 30. After irradiation the Price-Jones curve varied in a different manner and recovered by day 6. The changes in the curve were not correlated with variations in the reticulocyte and erythrocyte counts or hemoglobin content. It is concluded that an exposure to a constant magnetic field produces insignificant lesions in the red blood cell membrane. Mention should be made of a reduction of the reticulocyte count in the peripheral blood after exposure.

Plasma and red cell volumes of microwave irradiated mice tissues.

A double isotope technique was applied to the microwave irradiation of mice for reliable measurement of the distribution of red cells and plasma. Microwaves provide a means for rapid cessation of circulation. Hematocrit values of blood in minute tissue samples can be estimated. The red cell and plasma volumes as well as the hematocrit values of the liver, kidney, spleen, intestine, lung and brain tissues of mice are presented. A biological filtration of technetium labelled red cells is necessary for their physiological distribution in circulation.