OBJECTIVE: To investigate the effect of irradiation dose rate of ⁶⁰Co γ-ray on hematopoietic and immune cells in total body irradiation (TBI) mice. METHODS: After TBI with 8 Gy ⁶⁰Co γ-ray at three irradiation dose rates of 0.027, 0.256 and 0.597 Gy/min, the survival and change of body weight of C57BL/6J mice were observed within 30 days. The peripheral blood parameters were examined at each time point within 30 days post-irradiation. The hematopoietic stem/progenitor cell counts of mice were examined on the 10^th and 30^th day post-irradiation by flow cytometry, as well as the proportions of immune cells in peripheral blood, bone marrow and spleen of mice on the 30^th day post-irradiation. RESULTS: After TBI with 8 Gy ⁶⁰Co γ-ray, the 30-day survival rate of high dose-rate group was 0, which was significantly lower than 90% of medium dose-rate group and 100% of low dose-rate group (both P < 0.001). The peripheral blood parameters of all three groups showed a sharp decline → low value → gradually recovering trend. The count of white blood cell, neutrophil, lymphocyte, red blood cell, platelet and hemoglobin level in the high dose-rate and medium dose-rate groups were significantly lower than those in the low dose-rate group on day 7-18 post-irradiation (all P < 0.05), but there were no significant differences between the high dose-rate and medium dose-rate groups (P >0.05). On the 10^th day after irradiation, the proportion and number of bone marrow hematopoietic stem/progenitor cells (including LK, LSK, LT-HSC, ST-HSC, and MPP cells) in the low dose-rate and medium dose-rate groups were significantly decreased compared to those in the normal group (all P < 0.05), but there were no significant differences between the two groups (P >0.05). On the 30^th day after irradiation, LSK, LT-HSC, ST-HSC and MPP cells in the low dose-rate group recovered to normal levels, while those in the medium dose-rate group were still significantly lower than those in the low dose-rate group (all P < 0.001). The results of bone marrow and peripheral immune cell tests on the 30^th day after irradiation showed that the ratios of T and B lymphocytes in the low dose-rate and medium dose-rate groups were reduced compared to that in the normal group (both P < 0.05), while the ratio of neutrophils was increased (P < 0.01). The trend of changes in the spleen and peripheral blood was consistent. CONCLUSION The degree of hematopoietic and immune cell damage in mice after TBI with 8 Gy ⁶⁰Co γ-ray is related to the dose rate, and low dose-rate irradiation can reduce the damage in the animal model. Therefore, choosing the appropriate dose rate of irradiation is a key factor in establishing an objective and reliable experimental animal model of irradiation.
Animals ; Mice ; Whole-Body Irradiation ; Gamma Rays ; Mice, Inbred C57BL ; Hematopoietic Stem Cells/radiation effects* ; Cobalt Radioisotopes ; Dose-Response Relationship, Radiation ; Male

Objective: To detect the effects of shortwave radiation on dose-dependent cardiac structure and function in rats after radiation and to elucidate the mechanism of shortwave radiation induced cardiac injury to identify sensitive indicators and prophylactic treatment. Methods: One hundred Wistar rats were either exposed to 27 MHz continuous shortwave at a power density of 5, 10, and 30 mW/cm for 6 min or undergone sham exposure for the control (the rats had to be placed in the exposure system with the same schedules as the exposed animals, but with an inactive antenna). The Ca , glutamic oxaloacetic transaminase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) content in the peripheral serum of the rats were detected by an automatic blood biochemical analyser. The electrocardiogram (ECG) of standard lead II was recorded by a multi-channel physiological recording and analysis system. The cardiac structure of rats was observed by light and electron microscopy. Results: The results showed that the 5, 10, and 30 mW/cm shortwave radiation caused a significant increased in the levels of Ca , AST, CK, and LDH in the peripheral serum of rats. The cardiac structure was damaged by radiation and showed a disordered arrangement of myocardial fibres, the cavitation and swelling of myocardial mitochondria. These injuries were most significant 7 d after radiation and were not restored until 28 d after radiation. Conclusion Shortwave radiation of 5, 10, and 30 mW/cm can damage rat cardiac function, including damage to the tissue structure and ultrastructure, especially at the level of the myocardial fibres and mitochondria. Shortwave radiation at 5, 10, and 30 mW/cm induced damage to rat heart function and structure with a dose-effect relationship, i.e., the greater the radiation dose was, the more significant the damage was.
Animals ; Dose-Response Relationship, Radiation ; Heart ; radiation effects ; Heart Diseases ; ethnology ; pathology ; physiopathology ; Male ; Myocardium ; pathology ; Radio Waves ; adverse effects ; Random Allocation ; Rats ; Rats, Wistar

DNA Methylation ; radiation effects ; Dose-Response Relationship, Radiation ; Hematologic Neoplasms ; metabolism ; radiotherapy ; Neoplasms ; metabolism ; radiotherapy ; X-Rays

Hesperetin, an abundant bioactive component of citrus fruits, is poorly water-soluble, resulting in low oral bioavailability. We developed new formulations to improve the water solubility, antioxidant activity, and oral absorption of hesperetin. Two nano-based formulations were developed, namely hesperetin-TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) micelles and hesperetin-phosphatidylcholine (PC) complexes. These two formulations were prepared by a simple technique called solvent dispersion, using US Food and Drug Administration (FDA)-approved excipients for drugs. Differential scanning calorimetry (DSC) and dynamic light scattering (DLS) were used to characterize the formulations' physical properties. Cytotoxicity analysis, cellular antioxidant activity assay, and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations. The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility, which increased to 21.5- and 20.7-fold, respectively. The hesperetin-TPGS micelles had a small particle size of 26.19 nm, whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm. In addition, the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2- and 3.9-fold, respectively. Importantly, the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration (C_max) from 2.64 μg/mL to 20.67 and 33.09 μg/mL and also increased the area under the concentration-time curve of hesperetin after oral administration to 16.2- and 18.0-fold, respectively. The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin, indicating these formulations' potential applications in drugs and healthcare products.
Administration, Oral ; Animals ; Antioxidants/chemistry* ; Biological Availability ; Calorimetry, Differential Scanning ; Dogs ; Dose-Response Relationship, Drug ; Drug Carriers ; Female ; Hep G2 Cells ; Hesperidin/chemistry* ; Humans ; Light ; Madin Darby Canine Kidney Cells ; Micelles ; Phosphatidylcholines/chemistry* ; Polyethylene Glycols/chemistry* ; Rats ; Rats, Sprague-Dawley ; Scattering, Radiation ; Solubility ; Solvents ; Vitamin E/chemistry* ; Water/chemistry* ; alpha-Tocopherol/chemistry*

OBJECTIVE: To estimate the detrimental effects of shortwave exposure on rat hippocampal structure and function and explore the underlying mechanisms. METHODS: One hundred Wistar rats were randomly divided into four groups (25 rats per group) and exposed to 27 MHz continuous shortwave at a power density of 5, 10, or 30 mW/cm2 for 6 min once only or underwent sham exposure for the control. The spatial learning and memory, electroencephalogram (EEG), hippocampal structure and Nissl bodies were analysed. Furthermore, the expressions of N-methyl-D-aspartate receptor (NMDAR) subunits (NR1, NR2A, and NR2B), cAMP responsive element-binding protein (CREB) and phosphorylated CREB (p-CREB) in hippocampal tissue were analysed on 1, 7, and 14 days after exposure. RESULTS: The rats in the 10 and 30 mW/cm2 groups had poor learning and memory, disrupted EEG oscillations, and injured hippocampal structures, including hippocampal neurons degeneration, mitochondria cavitation and blood capillaries swelling. The Nissl body content was also reduced in the exposure groups. Moreover, the hippocampal tissue in the 30 mW/cm2 group had increased expressions of NR2A and NR2B and decreased levels of CREB and p-CREB. CONCLUSION Shortwave exposure (27 MHz, with an average power density of 10 and 30 mW/cm2) impaired rats' spatial learning and memory and caused a series of dose-dependent pathophysiological changes. Moreover, NMDAR-related CREB pathway suppression might be involved in shortwave-induced structural and functional impairments in the rat hippocampus.
Animals ; Cyclic AMP Response Element-Binding Protein ; genetics ; metabolism ; Dose-Response Relationship, Radiation ; Electroencephalography ; radiation effects ; Hippocampus ; radiation effects ; Male ; Memory ; radiation effects ; Nissl Bodies ; physiology ; radiation effects ; Radio Waves ; adverse effects ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism ; Spatial Learning ; radiation effects

There is still a need for better protection against or mitigation of the effects of ionizing radiation following conventional radiotherapy or accidental exposure. The objective of our current study was to investigate the possible roles of matrix metalloproteinase inhibitor, ilomastat, in the protection of mice from total body radiation (TBI), and the underlying protective mechanisms. Ilomastat treatment increased the survival of mice after TBI. Ilomastat pretreatment promoted recovery of hematological and immunological cells in mice after 6 Gy γ-ray TBI. Our findings suggest the potential of ilomastat to protect against or mitigate the effects of radiation.
Acute Radiation Syndrome ; blood ; immunology ; prevention & control ; Animals ; Blood Cells ; drug effects ; radiation effects ; Dose-Response Relationship, Drug ; Gamma Rays ; adverse effects ; Hydroxamic Acids ; therapeutic use ; Indoles ; therapeutic use ; Matrix Metalloproteinase Inhibitors ; therapeutic use ; Mice ; Radiation Injuries, Experimental ; blood ; immunology ; prevention & control ; Radiation-Protective Agents ; therapeutic use ; Spleen ; drug effects ; immunology ; radiation effects ; Survival Analysis ; Whole-Body Irradiation

The aim of the present study is to analyze the global research trend of radiation-responsive genes and identify the highly reproducible radiation-responsive genes. Bibliometric methods were applied to analyze the global research trend of radiation-responsive genes. We found 79 publications on radiation-responsive genes from 2000 to 2017. A total of 35 highly reproducible radiation-responsive genes were identified. Most genes are involved in response to DNA damage, cell proliferation, cell cycle regulation, and DNA repair. The p53 signal pathway was the top enriched pathway. The expression levels of 18 genes in human B lymphoblastoid cell line (AHH-1) cells were significantly up-regulated in a dose-dependent manner at 24 h after exposure to 0-5 Gy 60Co γ-ray irradiation. Our results indicate that developing a gene expression panel with the 35 high reproducibility radiation-responsive genes may be necessary for qualitative and quantitative assessment after exposure.
Dose-Response Relationship, Radiation ; Gene Expression Profiling ; Gene Expression Regulation ; radiation effects ; Humans ; Radiometry ; methods ; Reproducibility of Results ; Up-Regulation ; radiation effects

OBJECTIVETo investigate microwave-induced morphological and functional injury of natural killer (NK) cells and uncover their mechanisms.

METHODSNK-92 cells were exposed to 10, 30, and 50 mW/cm2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK (p-ERK) was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126.

RESULTSMicrowave-induced morphological and ultrastructural injury, dose-dependent apoptosis (P < 0.001) and cell cycle arrest (P < 0.001) were detected at 1 h after microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 mW/cm2 microwave exposure (P < 0.01). In the 30 mW/cm2 microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure (P < 0.05). Furthermore, p-ERK was down regulated at 1 h after exposure (P < 0.05), while ERK blockade significantly promoted microwave-induced apoptosis (P < 0.05) and downregulation of perforin (P < 0.01).

CONCLUSIONMicrowave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.

Apoptosis ; radiation effects ; Cell Cycle ; radiation effects ; Cell Line ; Dose-Response Relationship, Radiation ; Down-Regulation ; Humans ; Killer Cells, Natural ; radiation effects ; MAP Kinase Signaling System ; Microwaves ; adverse effects ; NK Cell Lectin-Like Receptor Subfamily K ; genetics ; metabolism ; Signal Transduction

PURPOSE: The correlation between radiation dose and loco-regional control (LRC) was evaluated in patients with stage II-III esophageal cancer treated with definitive concurrent chemoradiotherapy (CRT). MATERIALS AND METHODS: Medical records of 236 stage II-III esophageal cancer patients treated with definitive CRT at Yonsei Cancer Center between 1994 and 2013 were retrospectively reviewed. Among these, 120 received a radiation dose of < 60 Gy (standard-dose group), while 116 received ≥ 60 Gy (high-dose group). The median doses of radiation in the standard- and high-dose groups were 50.4 and 63 Gy, respectively. Concurrent 5-fluorouracil/cisplatin chemotherapy was administered to most patients. RESULTS: There were no differences in patient characteristics between the two groups except for high Karnofsky performance status and lower-thoracic lesions being more prevalent in the standard-dose group. The median progression-free survival (PFS) and overall survival (OS) times were 13.2 months and 26.2 months, respectively. Patients in the high-dose group had significantly better 2-year LRC (69.1% vs. 50.3%, p=0.002), median PFS (16.7 months vs. 11.7 months, p=0.029), and median OS (35.1 months vs. 22.3 months, p=0.043). Additionally, LRC exhibited a dose-response relationship and the complete response rate was significantly higher in the high-dose group (p=0.006). There were no significant differences in treatment-related toxicities between the groups. CONCLUSION: A higher radiation dose (> 60 Gy) is associated with increased LRC, PFS, and OS in patients with stage II-III esophageal cancer treated with definitive CRT.
Chemoradiotherapy* ; Disease-Free Survival ; Dose-Response Relationship, Radiation ; Drug Therapy ; Esophageal Neoplasms* ; Humans ; Karnofsky Performance Status ; Medical Records ; Retrospective Studies

To investigate hematopoiesis and cytogenetics changes in staff of interventional radiology.A total of 121 intervention radiation workers, 245 common radiation workers and 100 medical personnel (healthy control) without exposure to radiation were enrolled in the study. The peripheral lymphocyte chromosomal aberrations and micronucleus were detected, and the result of white blood cells examination was analyzed.Compared with common radiation group and healthy control group, decreases in white blood cells count, neutrophil ratio, and increase in lymphocyte ratio were observed in intervention radiation group (all<0.05). Intervention radiation group had higher chromosome aberration rate and micronuclear rate than common radiation group and healthy control group (all<0.05). Most common chromosome aberrations were dicentric chromosome, acentric ring, fragments and minute chromosome. Abnormal rates in chromosome aberration and micronucleus rates were increased with the rise of length of service, but no statistically significant difference was observed (>0.05).Long term exposure to ionizing radiation may lead to changes in the human hematopoietic system and cause human chromosome aberration, and the severity of such injuries may be associated with the dose of ionizing radiation.
Adult ; Chromosome Aberrations ; radiation effects ; Dose-Response Relationship, Radiation ; Female ; Hematopoiesis ; radiation effects ; Humans ; Leukocyte Count ; statistics & numerical data ; Leukocytes ; pathology ; radiation effects ; Lymphocytes ; pathology ; radiation effects ; ultrastructure ; Male ; Micronuclei, Chromosome-Defective ; radiation effects ; Occupational Exposure ; adverse effects ; Radiation Exposure ; adverse effects ; statistics & numerical data ; Radiation, Ionizing ; Radiologists ; statistics & numerical data ; Time Factors