The Effects of Medical Diagnostic Low Dose X-rays after in vitro Exposure of Human Red Blood Cells: Hemolysis and Osmotic Fragility

Effects of low-dose radiation on human blood components after in vitro exposure to gamma radiation from 137Cs radioactivity

This current study was designed to determine the effects of in vitro exposure to radioactive cesium-137 on human blood components. Whole blood samples were given a radiation dose of 0.02, 0.05, 0.1, 0.2, and 0.3 mGy of gamma radiation using a ¹³⁷Cs radioactive standard source. The whole blood samples that were exposed to 0 mGy served as sham-controls. The spectrofluoroscopic technique was used to determine the autofluorescence spectrum of protein in plasma or red blood cells by using excitation wavelength and range of emission wavelengths at 280 nm and 300-550 nm, respectively. The hemolysis of red blood cells was evaluated by determination of the release of hemoglobin from the red blood cells to the supernatant. Complete blood counts were also determined in whole blood. The results showed that there was no change in the ratio of fluorescence emission intensity at 340 nm of wavelength of protein extract from irradiated whole blood or red blood cells compared to the corresponding non-irradiated control. The hemolysis value did not change in irradiated whole blood when compared to the corresponding non-irradiated group. In addition, complete blood count values in irradiated groups did not differ from non-irradiated group. These current results suggested that there were no harmful effects of the low-dose gamma radiation from radioactive ¹³⁷Cs on blood components when human whole blood was exposed to gamma radiation in an in vitro condition.

Effects of gadolinium-based magnetic resonance imaging contrast media on red blood cells and K562 cancer cells

BACKGROUND

Gadolinium-based contrast media (GBCM) are commonly used in diagnostic magnetic resonance imaging (MRI) in clinical applications. The objective of this study is to evaluate the antioxidant properties and effects on red blood cells (RBCs) and K562 cancer cells of three GBCMs (i.e.; gadoterate meglumine, gadopentetate dimeglumine, and gadobenate dimeglumine) inin vitro levels.

METHODS

For determiningin vitro antioxidant properties, the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium (DPPH) and ferric reducing ability of plasma (FRAP) assay were used. For determining effect on red blood cells, hemolysis, morphology and reactive oxygen species (ROS) were used. For determining effect on K562 cancer cells, cytotoxicity and ROS were used. The GBCM -exposed cells were compared to corresponding non-exposed control groups at various harvest times.

RESULTS

The results show no changes occurring in the DPPH data. However, there were significant increases based on FRAP data in three GBCMs compared to the corresponding control at all concentrations. The ROS, morphology, and percentage of hemolysis in red blood cells indicated that no change had occurred in three GBCMs-exposed red blood cells compared to the corresponding non-exposed control groups at all harvest times. The percentage of cell viability in K562 cancer cells showed decreases in gadoterate meglumine- and gadobenate dimeglumine- in a concentration dependent manner, but did not show same in gadopentetate dimeglumine-exposed K562 cancer cells. The percentage of ROS in K562 cancer cells indicated that no change in three GBCMs-exposed cells had occurred when compared to the corresponding non-exposed control groups at all harvest times.

CONCLUSION

These findings suggests thatin vitro antioxidant properties exhibited by those three GBCMs depends on their concentration and species of radical in testing assay. There were no toxic effects from those GBCMs when red blood cells were exposed in an in vitro condition. In addition, some of those GBCMs could induce cell death in cancer cells.

Comparison of sample preparation methods, validation of an UPLC-MS/MS procedure for the quantification of cyclosporine A in whole blood sample

Current main methods for therapeutic drug monitoring (TDM) of cyclosporine A (CsA) are immunoassays and liquid chromatography tandem mass spectrometry. The sample pretreatment of these methods is mainly based on extraction of drug which is bound to erythrocytes by divalent heavy metal ions (such as zinc and copper). Although these methods are effective for whole blood drug extraction and measurement, the pollution of heavy metals in sample pretreatment process will have potential negative impact on environment and human health. To overcome the pollution problem, in this study we have developed and validated an UPLC-MS/MS method for CsA determination in whole blood samples using physical pretreatment method. According to the characteristics of erythrocytes, a series of physical pretreatment methods, including sonication, freeze-thaw and osmotic burst, have been developed and evaluated. The results showed that the osmotic burst method was an effective way for drug extraction from erythrocytes. The lower limit of quantitation for CsA was 25 ng/mL, the within-run and between-run coefficient of variations were both less than 11.6 %. The agreement of the UPLC-MS/MS methods using these two sample pretreatment was evaluated by Bland-Altman plot and the two-tailed Student's T-test. Comparison studies show that the effect of erythrocyte fragmentation by osmotic burst is similar to that of zinc sulfate method. The CsA measurement of 103 whole blood samples obtained by these two UPLC-MS/MS assays were no significant difference. These results demonstrate that the sample pretreatment by osmotic burst method is an eco-friendly and precise method for detecting the whole blood CsA concentration and therapeutic drug monitoring of CsA.