Melatonin ameliorates the production of COX-2, iNOS, and the formation of 8-ohdg in non-targeted lung tissue after pelvic irradiation

2 [COX-2], inducible nitric oxide synthase [iNOS], and 8-hydroxydeoxyguanosine [8-OHdG] in lung tissues of Sprague-Dawley rats with and without pre-administration of melatonin. A 2x2 cm[2] area of the pelvis of male Sprague-Dawley rats with and without pre-administration of melatonin [100 mg/kg] by oral and intraperitoneal injection was irradiated with a 3 Gy dose of 1.25 MeV gamma-rays. Alterations in the levels of COX-2, iNOS, and 8-OHdG in the out-of-field lung areas of the animals were detected by enzyme immunoassay. The bystander effect significantly increased COX-2, iNOS, and 8-OHdG levels in non-targeted lung tissues [P<0.05]. Melatonin ameliorated the bystander effect of radiation and significantly reduced the level of all examined biomarkers [P<0.05]. The results indicated that the ameliorating effect of a pre-intraperitoneal [IP] injection of melatonin was noticeably greater compared to oral pre-administration. Our findings revealed that the bystander effect of radiation could induce oxidative DNA damage and increase the levels of imperative COX-2 and iNOS in non-targeted lung tissues. Interestingly, melatonin could modulate the indirect destructive effect of radiation and reduce DNA damage in non-targeted cells

healing effect of bone marrow-derived stem cells in acute radiation syndrome

Objectives: To determine the effect of bone marrow-derived mesenchymal stem cells [BMSCs] on regeneration of bone marrow and intestinal tissue and survival rate in experimental mice with acute radiation syndrome [ARS]

Methods: Forty mice were randomly divided into two equal groups of A receiving no BMSC transplantation and B receiving BMSCs. BMSCs were isolated from the bone marrow and cultured in DMEM media. Both groups were irradiated with 10 Gy [dose rate 0.28 Gy/ min] 60CO during 35 minutes with a field size of 35×35 for all the body area. Twenty-four hours after gamma irradiation, 150×103 cells of passage 5 in 150 microl medium were injected intravenously into the tail. Animals were euthanized one and two weeks after cell transplantation. They were evaluated histologically for any changes in bone marrow and intestinal tissues. The survival rate in mice were also determined

Results: A significant increase for bone marrow cell count and survival rate were observed in group B in comparison to group A. Histological findings denoted to a healing in sample tissues

Conclusion: BMSCs could significantly reduce the side effects of ARS and increase the survival rate and healing in injured tissue. As such their transplantation may open a window in treatment of patients with ARS

Radiation-induced oxidative stress at out-of-field lung tissues after pelvis irradiation in rats

Objective: the out-of-field/non-target effect is one of the most important phenomena of ionizing radiation that leads to molecular and cellular damage to distant non-irradiated tissues. The most important concern about this phenomenon is carcinogenesis many years after radiation treatment. In vivo mechanisms and consequences of this phenomenon are not known completely. Therefore, this study aimed to evaluate the oxidative damages to out-of-field lung tissues 24 and 72 hours after pelvic irradiation in rats

Materials and Methods: in this experimental- interventional study, Sprague-Dawleymale rats [n=49] were divided into seven groups [n=7/each group], including two groups of pelvis-exposed rats [out-of-field groups], two groups of whole body- exposed rats [scatter groups], two groups of lung-exposed rats [direct irradiation groups], and one control sham group. Out-of-field groups were irradiated at a 2×2 cm area in the pelvis region with 3 Gy using 1.25 MeV cobalt-60 gamma-ray source, and subsequently, malondialdehyde [MDA] and glutathione [GSH] levels as well as superoxide dismutase [SOD] activity in out-of-field lung tissues were measured. Results were compared to direct irradiation, control and scatter groups at 24 and 72 hours after exposure. Data were analyzed using Mann-Whitney U test

Results: SOD activity decreased in out-of-field lung tissue 24 and 72 hours after irradiation as compared with the controls and scatter groups. GSH level decreased 24 hours after exposure and increased 72 hours after exposure in the out-of-field groups as compared with the scatter groups. MDA level in out-of-field groups only increased 24 hours after irradiation

Conclusion: pelvis irradiation induced oxidative damage in distant lung tissue that led to a dramatic decrease in SOD activity. This oxidative stress was remarkable, but it was less durable as compared to direct irradiation

Radioprotective effect of melatonin on radiation-induced lung injury and lipid peroxidation in rats

Free radicals generated by ionizing radiation attack various cellular components such as lipids. The lung is a very radiosensitive organ and its damage is a dose-limiting factor in radiotherapy treatments. Melatonin [MLT], the major product of the pineal gland acts as a radioprotective agent. This study aims to investigate the radioprotective effects of MLT on malondialdehyde [MDA] levels and histopathological changes in irradiated lungs. In this experimental study, a total of 62 rats were divided into five groups. Group 1 received no MLT and radiation [unT], group 2 received oral MLT [oM], group 3 received oral MLT and their thoracic areas were irradiated with 18 Gy [oM-R], group 4 received MLT by intraperitoneal [i.p.] injection and their thoracic areas were irradiated with 18 Gy [ipM-R], group 5 received only 18 Gy radiation in the thoracic area [R]. Following radiotherapy, half of the animals in each group were sacrificed at 48 hours for evaluation of lipid peroxidation and early phase lung injuries. Other animals were sacrificed in the eighth week of the experiment for evaluation of the presence of late phase radiation induced lung injuries. Pre-treatment of rats with either i.p injection [p<0.05] and oral administration of MLT [p<0.001] significantly reduced MDA levels in red blood cell [RBC] samples compared to the R group. Furthermore, i.p. injection of MLT decreased MDA levels in plasma and tissue [p<0.05]. In the early phase of lung injury, both administration of MLT sig-nificantly increased lymphocyte [p<0.05] and macrophage frequency [p<0.001]. MLT reduced the lung injury index in the lungs compared to the R group [p<0.05]. The result of this study confirms the radioprotective effect of MLT on lipid peroxidation, and in both early and late phases of radiation induced lung injuries in an animal model

Paratesticular liposarcoma; a case report

Paratesticular sarcomas have happened rarely. Due to the infrequency of this malignant disease and its diverse histopathologic subtypes, no standard treatment would be available. Multiple treatments have reported in literature with different results. We have reported a 55 years old man with a 30 years history of paratesticular mass. After multiple operations, radical orchiectomy has revealed liposarcoma. The patient has been receiving 50 Gy radiation to the scrotum and inguinal area. After 18 months follow up, the patient was well and disease free. He has shown good response to surgery and radiotherapy, so we have reported the disease and its clinical course

Effect of oral zinc sulphate in prevention of radiation induced oropharyngeal mucositis during and after radiotherapy in patients with head and neck cancers

Mucositis is a disturbing side effect of radiotherapy treatment for head and neck cancer. To date, no effective modality for its prophylaxis and treatment has been found. We performed this study to evaluate the efficacy of oral zinc sulphate in delaying the onset of oral and pharyngeal mucositis and decreasing their severity. A total of 58 patients who were treated for head and neck squamous cell carcinoma with radiotherapy or chemoradiotherapy were randomly assigned to receive oral zinc sulphate [220 mg] or an oral placebo 3 times a day during their radiotherapy course. Total radiation dose was 6000 cGy to 7000 cGy by conventional radiotherapy. Seventy nine percent of the patients also received concurrent chemotherapy. Oral and pharyngeal mucositis were scored according to an RTOG protocol. Time to onset of mucositis did not vary between the two groups. However, oral mucositis scores were less severe in the zinc group in weeks 4 to 6. The difference was statistically significant and the P values for weeks 4, 5 and 6 were 0.02, 0.007, and 0.012, respectively. Treatment interruptions in both groups were the same [four cases each] and all were due to dysphagia [pharyngeal mucositis]. Our results suggest that zinc is effective in reducing the severity of oral mucositis but not pharyngeal mucositis. Treatment interruptions were more frequently caused by pharyngeal mucositis which presented as dysphagia, rather than oral pain that was a manifestation of oral mucositis

[Optimization of beam orientation and weight in radiotherapy treatment planning using a genatic algorithm]

The selection of suitable beam angles and weights in external-beam radiotherapy is at present generally based upon the experience of the planner. Therefore, automated selection of beam angles and weights in forward-planned radiotherapy will be beneficial. In this work, an efficient method is presented within the MATLAB environment to investigate how to improve the dose distributions by selecting suitable coplanar beam angles and weights for the beam. In the beam angle and weight selection algorithm, the optimal beam angles and weights correspond to the lowest objective action value of the dose distributions of each group of candidate beams. Optimal weights and angles reach a balance between all the objectives. In this work, we used a genetic algorithm and adopted a real-number encoding method to represent both beam weights and angles with an assignable number of repetitions. For the evolution of this algorithm, we used bod monophasic and biphasic methods. In monophasic evolution, the chromosome containing the weights and angles is evolved in a single phase. In biphasic evolution, the chromosome is evolved while keeping me parameter [e.g., weight] constant and then, in the second phase, the evolution is continued while keeping the other parameter [e-g., angle] constant. The dose calculation was carried out using [correction-based techniques]. Simple and simulated clinical cases are presented to test the algorithm. They show that the biphasic evolution requires more computation time compared to monophasic [typically 40 and 20 minutes respectively] but results in a better optimization. The results show the efficacy of the algorithm and its fairly acceptable computation time