OBJECTIVETo investigate the ultrastructural variation of the facial nerve of rabbit with different dosage of (125)I seed brachytherapy.

METHODSFifty-four big ear rabbits were divided into 3 groups randomly and given 40 Gy, 80 Gy, 120 Gy respectively. Radioactive seeds were implanted in one side of parotid gland, the other side was implanted with vacant shell as a control group. The facial nerves were obtained 2, 4, 6 months respectively after operation and the histological ultrastructural changes observed by electromicroscope.

RESULTSIn the control group, epineurium was continuous, there was slight pitting edema under the epineurium, and axonal myelin was loose. In the test groups, there was slight pitting edema under the epineurium, and axonal myelin sheath was loose at 4th month. Macrophage and regenerated fibers were found in the 80 Gy group and myelin sheath lamellar separation, regeneration of nerve in the 120 Gy dosage. The myelin sheath lamellar was separated and axonal myelin loose in the test group at 6th month. Myelin sheath amellar separation and edema under the epineurium were found in the group of 80 Gy and 120 Gy.

CONCLUSIONSThe ultrastructure of the facial nerve is damaged by the dosage of 40 Gy, 80 Gy brachytherapy with (125)I seeds. The higher dosage the nerve receives, the more serious the damage will be. Both of the epineurium and axonal myelin sheath are integral and continuous 6 months after operation with dosage of 120 Gy.

Animals ; Brachytherapy ; Dose-Response Relationship, Radiation ; Facial Nerve ; radiation effects ; ultrastructure ; Female ; Iodine Radioisotopes ; administration & dosage ; radiation effects ; Male ; Rabbits ; Radiation Injuries, Experimental ; pathology ; Random Allocation

BACKGROUNDIrradiation dose and volume are the major physical factors of radiation-induced lung injury. The study investigated the relationships between the irradiation dose and volume in radiation-induced lung injury by setting up a model of graded volume irradiation of the rat lung.

METHODSAnimals were randomly assigned to three groups. The ELEKTA precise 2.03 treatment plan system was applied to calculate the irradiation dose and volume. The treatment plan for the three groups was: group 1 received a "high dose to a small volume" (25% volume group) with the mean irradiation volume being 1.748 cm(3) (25% lung volume); the total dose and mean lung dose (MLD) were 4610 cGy and 2006 cGy, respectively (bilateral AP-PA fields, source to axis distance (SAD) = 100 cm, 6MVX, single irradiation); Group 2 received a "low dose to a large volume" (100% volume group) with the mean irradiation volume being 6.99 cm(3) (100% lung volume); the total dose was 1153 cGy. MLD was 2006 cGy, which was the same as that of group 1 (bilateral AP-PA fields, SAD = 100 cm, 6MVX, single irradiation); Group 3 was a control group. With the exception of receiving no irradiation, group 3 had rest steps that were the same as those of the experimental groups. After irradiation, functional, histopathological, and CT changes were compared every two weeks till the 16th week.

RESULTSFunctionally, after irradiation breath rate (BR) increases were observed in both group 1 and group 2, especially during the period of 6th - 8th weeks. The changes of BR in the 100% volume group were earlier and faster. For the 25% volume group, although pathology was more severe, hardly any obvious increase in BR was observed. Radiographic changes were observed during the early period (the 4th week) and the most obvious changes manifested during the mediated period (the 8th week). The extensiveness of high density and the decreased lung permeability were presented in the 100% volume group, and ground glass opacity and patchy consolidation were presented in the 25% volume group without pleural effusion, pleural thickening, and lung shrinking. Morphologically, the 100% volume group mainly presented signs of vascular damage, including signs of vascular wall edemas, hypertrophy, and sclerosis. The 25% volume group mainly presented with erythrocyte cell exudation, inflammation, and parenchymal damage.

CONCLUSIONSThe delivery of a small dose of radiation to a large volume is not safe. A low dose smeared out over large volumes, albeit reversible, may lead to fatal respiratory dysfunction. Damage to the lung may be more dependent on the volume of irradiation than on the radiation dose. Clinically, the safest approach is to limit both the volume of the irradiated normal lung and the amount of received radiation.

Animals ; Dose-Response Relationship, Radiation ; Lung ; radiation effects ; Lung Injury ; etiology ; Radiation Injuries, Experimental ; Rats ; Rats, Wistar

OBJECTIVETo assess the radioactive damage induced by interstitial 125I seed implantation to the rabbit urethra.

METHODSWe implanted 24 rabbits with 125I seeds 1.0 cm to the urethra at the radiation dose of 14.8 MBq (Group A), 29.6 MBq (Group B) and 44.4 MBq (Group C), while a non-radioactive seed was implanted near the urethra of the controls (Group D). Four weeks later, we detected the radiation-induced pathological and morphological changes in the urethra by H&E, light microscopy and electron microscopy.

RESULTSFour weeks after the implantation, no obvious histopathological and ultrastructural changes were observed in the urethral tissues of the experimental rabbits as compared with the control group. The scores on the radioactive damages to the urethra obtained by light microscopy were (2.20 +/- 0.18), (2.23 +/- 0.15), (2.27 +/- 0.10) and (2.10 +/- 0.17) respectively in Group A, B, C and D, with no significant differences between the first three groups and the control (P > 0.05). And the scores on the FlaMeng semi- quantitative analysis of mitochondria in the experimental groups were (1.23 +/- 0.13), (1.34 +/- 0.25) and (1.41 +/- 0.30) respectively, not significantly different from (1.12 +/- 0.13) the control (P > 0. 05).

CONCLUSIONThe radioactive damage induced by 125I seeds to the urethra increases with the enhanced radiation dose. Intraoperative implantation of 125I seeds at the prescription dose has no obvious adverse effect on the rabbit urethra.

Animals ; Dose-Response Relationship, Radiation ; Iodine Radioisotopes ; adverse effects ; Male ; Microscopy, Electron ; Rabbits ; Radiation Injuries, Experimental ; etiology ; pathology ; Urethra ; pathology ; radiation effects ; ultrastructure

OBJECTIVETo evaluate the safety of iodine-125 seed implantation in the liver.

METHODSTwenty New Zealand rabbits were divided into control and treatment groups and in the latter, iodine-125 seeds of 37 MBq were implanted into the liver under CT guidance whereas nonradioactive seeds were implanted in the control rabbits. Four weeks after implantation, white blood cell count, liver functions, and renal functions were measured or evaluated for comparison with those before implantation. The rabbits were then anesthetized to collect the liver tissue for pathological examination with HE staining and cell apoptosis assay.

RESULTSObvious hepatic tissue necrosis was observed around the radioactive seeds in the treatment group. At a 5 mm distance to the seeds, a distinct boundary occurred between the necrotic hepatic cells and normal cells. The control rabbits, however, had normal liver structure around the seeds implanted. In situ cell apoptosis examination showed a distinct band of apoptotic cells in the liver tissue of rabbits in the treatment group, which was not found in the control group. Two weeks after iodine-125 irradiation, alanine aminotransferase significantly increased in the treatment group (t=6.285, P<0.001), but recovered two weeks later (t=2.002, P=0.06). No significant alterations occurred in aspartate aminotransferase, blood urea nitrogen, serum creatinine, hemoglobin, serum total bilirubin, white blood cell count, or platelet count after the seed implantation.

CONCLUSIONIodine-125 seed implantation in the liver results in conformal irradiation dose distribution without obvious effects on the vital organs, demonstrating iodine-125 seed implantation as a safe and minimally invasive technique for hepatic cancer treatment.

Alanine Transaminase ; blood ; Animals ; Apoptosis ; radiation effects ; Dose-Response Relationship, Radiation ; In Situ Nick-End Labeling ; Iodine Radioisotopes ; adverse effects ; Liver ; pathology ; physiopathology ; radiation effects ; Male ; Rabbits ; Radiation Injuries, Experimental ; blood ; etiology ; pathology ; Random Allocation ; Time Factors

OBJECTIVETo investigate the relationship between single dosage of 60Co radiation and the degree of radiation-induced skin ulcers, and to evaluate the curative effect of Heijiang Pill (HJP) on skin ulcer induced by various dosages of radiation in rats.

METHODSSixty-six Wistar female rats were randomly divided into three groups, the blank control group (n = 6) and the two radiation groups, each 30 rats, with their right hind leg exposed respectively to 60 Gy and 40 Gy of 60 Co radiation. The time of emergence and degree of skin ulcer were recorded. Then rats in the two radiation groups were subdivided into the HJP group, the Ethacridine group and the model group, 10 in each group, they received corresponding treatment after ulceration, and the incidence, pathology, cure rate and cure time of skin ulcer were observed in the 90 days of observation.

RESULTSThe incidence of skin ulcer was higher and occurred earlier in rats radiated with 60 Gy than that with 40 Gy (P < 0.05). In the same radiation dosage, the ulcer healing rate in rats treated with HJP was higher than that treated with Ethacridine (P <0.05), and in the subgroups of 40 Gy radiation, the mean cure time in the HJP group was shorter (P < 0.05). The local epithelial proliferation and repairing could be verified by pathological observation in the HJP group.

CONCLUSIONLarger dosage of radiation leads to earlier emergence and aggravation of ulcers. HJP can effectively cure radiation skin ulcer, and the effect is especially significant on the ulcer induced by low dose radiation.

Animals ; Dose-Response Relationship, Radiation ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Female ; Radiation Injuries, Experimental ; drug therapy ; Rats ; Rats, Wistar ; Skin Ulcer ; drug therapy ; Tablets

BACKGROUND/AIMS: The increasing use of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) calls for greater consideration of radiation exposure risk to endoscopists and assistants, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a newly developed, self-designed, protective lead shield. METHODS: A curtain-shaped protective shield composed of seven movable lead plates was developed, each with the following dimensions: depth, 0.1 cm; width, 15 cm; length, 70 cm. The curtain-shaped protective shield was designed to be located between the patient and the endoscopist. Twenty-nine patients (11 men and 18 women) undergoing ERCP between January 2010 and March 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective lead shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. RESULTS: The mean patient age was 64 years. The mean patient height and weight was 161.7+/-6.9 cm and 58.9+/-9.9 kg, respectively. The mean body mass index (BMI) was 22.5+/-3.0 kg/m2. Endoscopists received 1522.2+/-537.0 mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to 68.8+/-88.0 mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to endoscopists and assistants was significantly reduced by the use of a protective lead shield (p value<0.0001). The amount of radiation exposure during ERCP was related to the patient's BMI (r=0.749, p=0.001). CONCLUSIONS: This self-designed, protective lead shield is effective in protecting endoscopists and assistants from radiation exposure.
Adult ; Aged ; Body Mass Index ; Cholangiopancreatography, Endoscopic Retrograde/*adverse effects ; Common Bile Duct Diseases/diagnosis/therapy ; Female ; Humans ; Male ; Middle Aged ; Radiation Dosage ; Radiation Injuries/*prevention & control ; *Radiation Monitoring/methods ; Radiation Protection/*methods

OBJECTIVE: To investigate the protective effect of abnormal savda munzip on the radiation-induced damaged in mice. METHODS: The mice were randomly divided into 2 groups: a control group and a drug group; the latter was again divided into a low dosage group (6.25%), a moderate dosage group (12.5%) and a high dosage group (25%) according to the drug concentration. All mice were given general radiation emitted by 6 Gy MV-X liner accelerator once, which resulted in the acute radiation damage. The different administrations of abnormal savda munzip were fed to the mice in the drug group orally for 7 days consecutively before and after the radiation. On the day of the last administration, 10 mice were sacrificed, and white blood cells, red cells and blood plates of the peripheral blood, spleen index, and spleen SOD were detected; while the 20 remaining mice were fed continually till 30 days, and the 30 day survival ratio of the mice was calculate. RESULTS: (1) Although the mice weight in the drug groups was higher than that in the control group, no significant difference existed (P>0.05). Spleen index in the control group was higher than that in the drug group. (2) Spleen SOD was significantly increased by the drugs compared with that of the control group (P<0.01), which was positively related to the drug concentration. (3) Pre-treatment of mice with the extract of abnormal savda munzip significantly increased the white cells and red cells in the peripheral blood compared with the control group (P<0.05). The blood cells were positively related to the drug concentration (P<0.05). Although the counts of blood plates in all drug groups were higher than those in the control group, no significant difference existed (P>0.05). (4) Compared with the control group, a marked improvement of 30 day survival rate in all drug groups was observed (P<0.0001). Both the concentration and the survival rate were increased (P<0.01). (5) The SOD level and leukocyte counts in the irradiated mice were positively related to the survival ratio (r=0.612, P<0.005; r=0.32, P<0.05, respectively). CONCLUSION The abnormal savda munzip has significant protective function on the mice irradiated by 7 Gy MV-X liner accelerator.
Administration, Oral ; Animals ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Male ; Mice ; Radiation Injuries, Experimental ; drug therapy ; mortality ; Radiation-Protective Agents ; administration & dosage ; therapeutic use ; Random Allocation ; Spleen ; drug effects ; enzymology ; Superoxide Dismutase ; metabolism ; Survival Rate ; Time Factors ; Whole-Body Irradiation

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

OBJECTIVETo explore the effect of NAD+ against radiation injury and its dose-effect relationship.

METHODSL02 liver cells cultured in RPMI 1640 medium containing 10% fetal calf serum were exposed to X-ray irradiation followed by immediate application of NAD+. The cellular viability was analyzed by MTT assay and the apoptotic cells were detected by TUNEL methods to observe the damages of L02 liver cells induced by X-ray exposure and analyze the dose-effect relationship of NAD+.

RESULTSThe viability of L02 liver cells was decreased with increasing dose of X-ray irradiation. The most obvious growth inhibition of L02 cells occurred 24 h after the irradiation. NAD+ significantly increased the cell survival rate after irradiation, and this effect was gradually increased within the concentration range of 100-1000 microg/ml; at higher concentrations, the survival rate of the irradiated L02 cells showed no significant increase.

CONCLUSIONNAD+ provides partial protection of the liver cells against radiation injury, and the effect is positively correlated to NAD+ concentration within a certain range.

Apoptosis ; drug effects ; radiation effects ; Cell Line ; Cell Survival ; drug effects ; radiation effects ; Dose-Response Relationship, Drug ; Hepatocytes ; cytology ; drug effects ; radiation effects ; Humans ; NAD ; administration & dosage ; pharmacology ; Radiation Injuries ; prevention & control

Radiation therapy is an important treatment modality for abdominal or pelvic cancer, but there is a common and serious complication such as radiation-induced enteritis. Probiotics is reported to have positive effects against radiation-induced enteropathy. In this study, morphological changes of bowel mucosa were analyzed in rats to presume the effect of probiotics on radiation-induced enteritis and its correlation with radiation dose. A total of 48 adult male Sprague-Dawley rats were randomly assigned to two groups and received a solution containing 1.0x108 colony-forming units of Lactiobacillus acidophilus or water once daily for 10 days. Each of two groups was divided into three subgroups and abdomino-pelvic area of each subgroup was irradiated with 10, 15, and 20 Gy, respectively on the seventh day of feeding the solutions. All rats were sacrificed 3 days after irradiation and the mucosal thickness and villus height of jejunum, ileum and colon were measured. The morphological parameters of the small intestine represented significant differences between two solution groups irradiated 10 or 15 Gy, except for villus height of jejunum in 15 Gy-subgroup (P=0.065). There was no significant morphometric difference between two groups irradiated with 20 Gy of radiation. Probiotics appear to be effective for the morphological shortening of small intestinal mucosa damaged by radiation less than or equal to 15 Gy.
Animals ; Colon/pathology ; Disease Models, Animal ; Enteritis/pathology/prevention & control ; Ileum/pathology ; Intestinal Mucosa/microbiology/*radiation effects ; Intestine, Small ; Jejunum/pathology ; Lactobacillus acidophilus/*metabolism ; Male ; Probiotics/administration & dosage/*pharmacology ; Radiation Injuries, Experimental/*prevention & control/therapy ; Radiation Protection/*methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley