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Background: Radiotherapy, a highly effective method of radiation-based treating cancers, can reduce the size of tumors and affect healthy tissues. Radiation-induced lymphopenia as a side effect of radiation therapy can reduce the effectiveness of the treatment. Objective: This study aimed to examine how taurine can protect peripheral blood lymphocytes from radiation-based apoptosis. Material and Methods: In this experimental study, the effects of the taurine on lymphocytes were studied, and blood samples were divided into three groups: a negative control group that was not treated, a positive control group that was treated with cysteine (100 μg/ml), and a group that was treated with taurine (100 µg. mL-1) in three different doses (4, 8 & 12 Gy) before irradiation. The percentage of apoptotic and necrotic lymphocytes was measured using flow cytometry 48 and 72 hours after the irradiation, respectively. Results: According to the groups treated with taurine, the number of lymphocytes undergoing apoptosis was lower and higher compared to the negative and positive control groups, respectively. The decrease in this value was more pronounced 48 hours after radiation compared to 72 hours. Furthermore, there was a slight increase in the number of apoptotic lymphocytes with increasing radiation dose. Conclusion: Taurine effectively protects human peripheral blood lymphocytes from radiation-based apoptosis. [ABSTRACT FROM AUTHOR]

Background: High-dose radiation altering the genetic material in patients' bone marrow cells can lead to hematopoietic radiation syndrome. Accordingly, the presence of radiation protections agents is critical to preventing these adverse effects. Objective: This study aimed to evaluate the radioprotection of the exclusive or combination effect of resveratrol and crocin extracts at various concentrations on irradiated human lymphocytes. Material and Methods: In this experimental study, the 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to evaluate the cell viability in pre-treatment with resveratrol, crocin, or a combination of both, using a concentration range of 5 to 4800 μM / ml in 24 h. The chromosomal aberration test was employed to determine the aberration frequency in 48 h. This study was performed on human peripheral blood lymphocytes treated with 2 Gy radiation and reliability of measurements performed by the triplicate repeat. Results: MTT results showed that the groups treated with either resveratrol or crocin at concentrations of 5 to 4800 µM had no significant reduction in cell viability. The cytogenetic analysis of irradiated lymphocytes with 2 Gy X-rays revealed a reduction in the frequency of dicentric chromosomes in all treated groups in contrast with the control group. The most significant reduction occurred in those treated with a single agent at the concentration of 100 µM and a combined drug at the concentration of 50 µM. Conclusion: The combination of resveratrol and crocin is considered a potential radioprotector and prophylactic for patients before radiation therapy. [ABSTRACT FROM AUTHOR]

Aim: The purpose of this study was to set four NTCP models on clinical data and develop a model that calculates the possibility of hearing damage due to irradiation of healthy and at-risk brainstem tissue. Materials and Methods: ABR tests were performed on 50 head-and-neck cancer patients three years after radiotherapy for evaluation of lesions in a part of the auditory nerve or the auditory pathway in the brainstem. Results: It indicated a significant difference in the latency of the waves assessed by the ABR test between the two groups. The paired sample t-test indicated the latency time of waves I, III, V, I-III, and I-V (P < 0.001) in the right ear, and in the left ear latency time of waves III, V, I-III, I-V, and III-V (P < 0.001) were significantly higher in the case group's ear than those in the control group. The confidence interval of the fitted parameters was 95% for NTCP models. ABR test's binary outcome with differential dose-volume histograms (dDVHs) was calculated and imported as input to the NTCP modeling. The values of the parameters n = 2.3-2.9 and the value s = 1 were obtained, which indicated that the brainstem organ is seriality. Conclusion: The best model ranked for the prediction of brainstem hearing damage was the logit model, which had the lowest Akaike value. The nervousness of the auditory organ of the brainstem (VIII nerve) can be declared as one of the reasons for being independent of the received dose. [ABSTRACT FROM AUTHOR]