scholarly journals Thiamine prevents X-ray induction of genetic changes in human lymphocytes in vitro.

2004 ◽  
Vol 51 (3) ◽  
pp. 839-843 ◽  
Author(s):  
Maria Konopacka ◽  
Jacek Rogoliński
Keyword(s):  
Nuclear Division ◽  
Morphological Changes ◽  
Human Lymphocytes ◽  
Vitamin B1 ◽  
X Rays ◽  
Genetic Changes ◽  
X Ray ◽  
Radiation Induced ◽  
Nuclear Division Index

The effects of thiamine (vitamin B1) on the level of spontaneous or radiation-induced genetic changes in human lymphocytes in vitro were studied. Cultured lymphocytes were exposed to increasing concentrations of thiamine (0-500 microg/ml) and irradiated with X-rays. The DNA damage was estimated as the frequency of micronuclei and apoptotic or necrotic morphological changes in fixed cells. The results show that thiamine alone did not induce genetic changes. A significant decrease in the fraction of apoptotic and necrotic cells was observed in lymphocytes irradiated in the presence of vitamin B1 at concentrations between 1-100 microg/ml compared to those irradiated in the absence of thiamine. Vitamin B1 at 1 and 10 microg/ml decreased also the extent of radiation-induced formation of micronuclei. Vitamin B1 had no effect on radiation-induced cytotoxicity as measured by nuclear division index. The results indicate that vitamin B1 protects human cells from radiation-induced genetic changes.

ATM and RAD51 Repair Pathways in Human Lymphocytes Irradiated with 70 MeV Therapeutic Proton Beam

2021 ◽  
Author(s):  
Agnieszka Panek ◽  
Justyna Miszczyk
Keyword(s):  
Proton Beam ◽  
Human Lymphocytes ◽  
Strand Break ◽  
Double Strand Break ◽  
Double Strand Break Repair ◽  
X Rays ◽  
X Ray ◽  
Post Irradiation ◽  
Repair Protein ◽  
Radiation Induced

The repair of radiation-induced DNA damage is a key factor differentiating patients in terms of the therapeutic efficacy and toxicity to surrounding normal tissue. Proton energy substantially determines the types of cancers that can be treated. The present work investigated the DNA double-strand break repair systems, represented by phosphorylated ATM and Rad51. The status of proton therapy energy used to treat major types of cancer is summarized. Here, human lymphocytes from eight healthy donors (male and female) were irradiated with a spread-out Bragg peak using a therapeutic 70 MeV proton beam or with reference X rays. For both types of radiation, the kinetics of pATM and Rad51 repair protein activation (0–24 h) were estimated as determinants of homologous and non-homologous double-strand break repair. Additionally, γ-H2AX was used as the gold standard marker of double-strand breaks. Our results showed that at 30 min postirradiation there was significantly greater accumulation of γ-H2AX (0.6-fold), pATM (2.0-fold), and Rad51 (0.6-fold) in the proton-irradiated cells compared with the X-ray-treated cells. At 24 h post irradiation, for both types of radiation and all investigated proteins, the foci number was still significantly higher when compared with control. Furthermore, the mean value of pATM and Rad51 repair effectiveness was higher in cells exposed to protons than in cells exposed to X rays; however, the difference was significant only for pATM. The largest inter-individual differences in the repair capabilities were noted for Rad51. The association between the frequency of repair protein foci and the frequency of lymphocyte viability at 1 h post irradiation showed a positive correlation for protons but a negative correlation for X rays. These findings indicate that the accumulation of radiation-induced repair protein foci after proton versus X-ray irradiation differs between patients, consequently affecting the cellular responses to particle therapy and conventional radiation therapy.

The inhibition of p21 on irradiation-induced apoptosis in EL-4 cells.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13558-e13558
Author(s):  
Feng-qin Yan ◽  
Jian-qiu Wang ◽  
Shi-bo Fu ◽  
Fang-zheng Wang ◽  
Zhen-fu Fu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ionizing Radiation ◽  
Time Course ◽  
Apparent Difference ◽  
X Rays ◽  
X Ray ◽  
Radiation Induced ◽  
Induced Apoptosis ◽  
Diploid Cells

e13558 Background: To elucidate the effect of p21 on ionizing radiation-induced apoptosis in EL-4 cells. Methods: In EL-4 cells, RT-PCR, immunocytochemistry and flow cytometry (FCM) were used to analyze the changes in the expression of p21 with time and doses caused by ionizing radiation; RNAi was used to silence the expression of p21 in EL-4 cells; FCM was applied to analyze the distribution of cell cycle,the number of the chromosome and the apoptosis in wild or p21-silencing EL-4 cells exposed to X-rays. Results: In EL-4 cells, p21 protein level was markedly increased at 8 ~ 72 h after exposure in 4.0 Gy of X-ray in vitro (p<0.01), as well as exposed in 1.0 ~ 4.0 Gy of X-ray at 24 h in vitro (p<0.05). Results of time-course experiments showed that, in EL-4 cells exposed to 4.0 Gy X-rays, the percentage in G0/G1 phase increased while that in S phase decreased, significantly different with the sham-irradiated groups (p<0.05), during 8-48h after exposure; the percentage of diploid cells increased significantly during 8-48 h (p<0.01), and the percentage of tetraploid and octoploid cells decreased significantly at 2 h and 8 h (p<0.05); the percentage of apoptosis during 2-72 h increased significantly (p<0.05-p<0.01). Compared with wild EL-4 cells, in p21-silencing EL-4 cells, the distribution of cell cycle had no apparent difference; the percentage of diploid cells decreased significantly and the percentage of octoploid cells increased significantly (p<0.01); the percentage of apoptosis increased significantly (p<0.05). Conclusions: p21 inhibited the apoptosis induced by ionizing radiation in EL-4 cells.

In vitro evaluation of the genotoxicity of ritodrine and verapamil in human lymphocytes

2010 ◽  
Vol 30 (5) ◽  
pp. 398-405 ◽  
Author(s):  
O. Milošević-Djordjević ◽  
D. Grujičić ◽  
G. Joksić ◽  
D. Marinković
Keyword(s):  
Nuclear Division ◽  
Human Lymphocytes ◽  
Combined Treatment ◽  
Fish Analysis ◽  
Human Peripheral Lymphocytes ◽  
Nuclear Division Index ◽  
The Difference ◽  
Clastogenic Effect

The aim of this study was to investigate the genotoxic effects of ritodrine and verapamil on human peripheral lymphocytes in vitro using micronucleus (MN) test. Also, fluorescence in situ hybridization (FISH) with a centromeric probe was performed to determine the origin of the induced MN. Cells were treated with 8.4 × 10 —6 M — 25.2 × 10— 4 M concentrations for ritodrine and 0.56—11 × 10— 5 M concentrations for verapamil, separately and combined. The MN frequencies showed increase after all treatments, but the difference between treated cells and untreated controls were found to be statistically significant only in the concentration range from 8.4 × 10— 5 M — 4.5 × 10—4 M for ritodrine, 1.1 — 3.3 × 10—5 M for verapamil, and in combined treatment with concentrations 8.4 × 10 —5 M + 1.1 × 10—5 M for ritodrine and verapamil. The highest tested concentrations of both medicaments showed cytotoxic effect. Both medicaments decreased the nuclear division index (NDI) in tested concentrations. The results of FISH analysis suggest that verapamil, separately or combined with ritodrine, shows to a larger extent aneugenic than clastogenic effect.

scholarly journals Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Radiation Dose ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Optical Coherence ◽  
X Rays ◽  
High Quality ◽  
X Ray

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

scholarly journals Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1676
Author(s):  
Giulia Rossi ◽  
Martina Placidi ◽  
Chiara Castellini ◽  
Francesco Rea ◽  
Settimio D'Andrea ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cellular Damage ◽  
X Rays ◽  
Adolescent Cancer ◽  
Radiation Induced ◽  
Vitro Model ◽  
Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

scholarly journals Evaluation of Possible Genotoxic Activity of Dirithromycin in Cultured Human Lymphocytes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmet Kayraldız ◽  
Lale Dönbak ◽  
Ayşe Yavuz Kocaman ◽  
Esra Köker ◽  
Şule Gökçe
Keyword(s):  
Bacterial Infections ◽  
Human Lymphocytes ◽  
Sister Chromatid Exchanges ◽  
Mutagenic Action ◽  
Replication Index ◽  
Different Types ◽  
Nuclear Division Index ◽  
Almost All ◽  
Chromatid Exchanges

Dirithromycin antibiotic is a 14-membered lactone ring macrolide and is widely used in medicine to treat many different types of bacterial infections. In the present study, the possible genotoxicity of dirithromycin was evaluated in cultured human lymphocytes by using sister chromatid exchanges (SCEs), chromosome aberration (CA), and micronucleus (MN) tests and also cell proliferation kinetics such as mitotic index (MI), replication index (RI), and nuclear division index (NDI) were analyzed for cytotoxicity. Cell cultures were treated with four different concentrations of dirithromycin (37.75, 67.50, 125, and 250 µg/mL) for 24 and 48 h periods. Dirithromycin significantly induced SCE and MN frequency at all concentrations in both 24 and 48 h treated cells. In addition, CA level has been markedly increased in the cells treated with almost all concentrations of dirithromycin for 24 (except 37.75 µg/mL) and 48 h treatment periods as compared to control. However, MI, RI, and NDI values were not affected by the dirithromycin treatment (p> 0.05). The results of this study indicated that dirithromycin treatment caused genetic damage by increasing the level of cytogenetic endpoints, suggesting its genotoxic and mutagenic action on human lymphocytesin vitro.

scholarly journals Biological Entanglement–Like Effect After Communication of Fish Prior to X-Ray Exposure

Dose-Response ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 155932581775006 ◽  
Author(s):  
Carmel Mothersill ◽  
Richard Smith ◽  
Jiaxi Wang ◽  
Andrej Rusin ◽  
Cris Fernandez-Palomo ◽  
...  
Keyword(s):  
Bystander Effect ◽  
X Ray ◽  
Before And After ◽  
Group A ◽  
Signal Production ◽  
Radiation Induced ◽  
Plant Photosynthesis ◽  
Radiation Induced Bystander Effect ◽  
Proteomic Responses

The phenomenon by which irradiated organisms including cells in vitro communicate with unirradiated neighbors is well established in biology as the radiation-induced bystander effect (RIBE). Generally, the purpose of this communication is thought to be protective and adaptive, reflecting a highly conserved evolutionary mechanism enabling rapid adjustment to stressors in the environment. Stressors known to induce the effect were recently shown to include chemicals and even pathological agents. The mechanism is unknown but our group has evidence that physical signals such as biophotons acting on cellular photoreceptors may be implicated. This raises the question of whether quantum biological processes may occur as have been demonstrated in plant photosynthesis. To test this hypothesis, we decided to see whether any form of entanglement was operational in the system. Fish from 2 completely separate locations were allowed to meet for 2 hours either before or after which fish from 1 location only (group A fish) were irradiated. The results confirm RIBE signal production in both skin and gill of fish, meeting both before and after irradiation of group A fish. The proteomic analysis revealed that direct irradiation resulted in pro-tumorigenic proteomic responses in rainbow trout. However, communication from these irradiated fish, both before and after they had been exposed to a 0.5 Gy X-ray dose, resulted in largely beneficial proteomic responses in completely nonirradiated trout. The results suggest that some form of anticipation of a stressor may occur leading to a preconditioning effect or temporally displaced awareness after the fish become entangled.

scholarly journals Clinical Evaluation of an in Vitro Test for Radiosensitivity of Leukemic Lymphocytes

Blood ◽  
1962 ◽  
Vol 20 (4) ◽  
pp. 432-442 ◽  
Author(s):  
ROBERT SCHREK ◽  
STANLEY L. LEITHOLD ◽  
IRVING A. FRIEDMAN ◽  
WILLIAM R. BEST
Keyword(s):  
Survival Time ◽  
Median Survival ◽  
Median Survival Time ◽  
Leukocyte Count ◽  
In Vitro Test ◽  
X Rays ◽  
X Ray ◽  
Leukocyte Counts ◽  
Vitro Test

Abstract A recently developed slide-chamber method was used to test the radiosensitivity of blood lymphocytes from 80 patients with chronic lymphocytic or lymphosarcoma-cell leukemia. The objective of this study was to determine whether these in vitro tests on sensitivity to x-rays had any clinical significance. Two objective criteria were used to measure the clinical reactions of the leukemic patients. The first was the duration of survival of patients following the in vitro test. The second was the minimal leukocyte count of a patient following x-ray therapy; the minimal count was expressed as a percentage of the count before therapy. The in vitro radiosensitivity was measured by the 10 per cent survival time of lymphocytes irradiated with 1000 r. Blood lymphocytes from non-leukemic individuals were highly radiosensitive with indices of 1.1 to 2.2 days. In initial tests, the lymphocytes of 61 leukemic patients had the same high sensitivity to x-rays as lymphocytes from non-leukemic individuals. In contrast, the lymphocytes of 19 leukemic patients were radioresistant to irradiation with indices of 2.5 to 11 days. The 61 patients with radiosensitive lymphocytes had a median survival time of 22 months after the in vitro test. In contrast, the 19 patients with radioresistant lymphocytes had a median survival time of only 4 months. Clinical x-ray therapy caused a greater decline in leukocyte counts in patients with radiosensitive lymphocytes than in those with radioresistant cells. A significant index of 0.60 was obtained for the correlation of in vitro radiosensitivity of lymphocytes and the in vivo decrease in leukocyte counts of patients after x-ray therapy. It is concluded that an in vitro finding of radioresistant lymphocytes is correlated with a poor response of the leukocyte count to x-ray therapy and a short survival time of the patient.

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