THE TEMPORAL RESPONSE OF RECOMBINATION EVENTS TO GAMMA RADIATION OF MEIOTIC CELLS IN SORDARIA BREVICOLLIS

1982 ◽  
Vol 24 (5) ◽  
pp. 505-519 ◽  
Author(s):  
Leslie A. Lewis
Keyword(s):  
Ionizing Radiation ◽  
Gamma Radiation ◽  
Recombination Frequency ◽  
S Phase ◽  
Temporal Response ◽  
Prophase I ◽  
Radiation Induced ◽  
Meiotic Cycle

The temporal frequencies of different stages of prophase I were determined cytologically in Sordaria brevicollis (Olive and Fantini) as the basis for ascertaining the degree of synchrony in meiosis in this ascomycete. Croziers, karyogamy-zygotene and pachytene asci were shown to be in significant majorities at three distinct periods of the meiotic cycle. The response of recombination frequency to ionizing radiation was examined for the entire meiotic cycle. Three radiosensitive periods were determined. This response, which correlated temporally with each of the three peaks in ascal frequency, is interpreted as showing that the meiotic cycle of this organism is divided into periods of recombination commitment (radiation reduced frequencies) during the pre-meiotic S phase and recombination consummation (radiation induced frequencies) during zygotene and pachytene. The results are discussed in the context of the time at which recombination is consummated in eukaryotes such as yeast and Drosophila.

scholarly journals Drosophila Caliban mediates G1-S transition and ionizing radiation induced S phase checkpoint

Cell Cycle ◽  
2018 ◽  
Vol 17 (18) ◽  
pp. 2256-2267
Author(s):  
Fanghua Song ◽  
Dong Li ◽  
Yajie Wang ◽  
Xiaolin Bi
Keyword(s):  
Ionizing Radiation ◽  
S Phase ◽  
Radiation Induced ◽  
S Phase Checkpoint

scholarly journals Gamma Radiation-Induced Damage in the Zinc Finger of the Transcription Factor IIIA

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
XiaoHong Zhang ◽  
YuJi Miao ◽  
XiaoDan Hu ◽  
Rui Min ◽  
PeiDang Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Ionizing Radiation ◽  
Gamma Radiation ◽  
Zinc Finger ◽  
Cysteine Residues ◽  
Zinc Finger Motif ◽  
Thiol Groups ◽  
Transcription Factor Iiia ◽  
Zinc Finger Motifs ◽  
Radiation Induced

A zinc finger motif is an element of proteins that can specifically recognize and bind to DNA. Because they contain multiple cysteine residues, zinc finger motifs possess redox properties. Ionizing radiation generates a variety of free radicals in organisms. Zinc finger motifs, therefore, may be a target of ionizing radiation. The effect of gamma radiation on the zinc finger motifs in transcription factor IIIA (TFIIIA), a zinc finger protein, was investigated. TFIIIA was exposed to different gamma doses from 60Co sources. The dose rates were 0.20 Gy/min and 800 Gy/h, respectively. The binding capacity of zinc finger motifs in TFIIIA was determined using an electrophoretic mobility shift assay. We found that 1000 Gy of gamma radiation impaired the function of the zinc finger motifs in TFIIIA. The sites of radiation-induced damage in the zinc finger were the thiol groups of cysteine residues and zinc (II) ions. The thiol groups were oxidized to form disulfide bonds and the zinc (II) ions were indicated to be reduced to zinc atoms. These results indicate that the zinc finger motif is a target domain for gamma radiation, which may decrease 5S rRNA expression via impairment of the zinc finger motifs in TFIIIA.

scholarly journals Improved Killing of Human High-Grade Glioma Cells by Combining Ionizing Radiation with Oncolytic Parvovirus H-1 Infection

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Karsten Geletneky ◽  
Andreas D. Hartkopf ◽  
Robert Krempien ◽  
Jean Rommelaere ◽  
Joerg R. Schlehofer
Keyword(s):  
Ionizing Radiation ◽  
Glioma Cells ◽  
High Grade Glioma ◽  
S Phase ◽  
High Grade ◽  
Virus Particles ◽  
Radiation Induced ◽  
Oncolytic Activity ◽  
Previous Irradiation ◽  
Different Doses

Purpose. To elucidate the influence of ionizing radiation (IR) on the oncolytic activity of Parvovirus H-1 (H-1PV) in human high-grade glioma cells.Methods. Short term cultures of human high-grade gliomas were irradiated at different doses and infected with H-1PV. Cell viability was assessed by determining relative numbers of surviving cells. Replication of H-1PV was measured by RT-PCR of viral RNA, fluorescence-activated cell sorter (FACS) analysis and the synthesis of infectious virus particles. To identify a possible mechanism for radiation induced change in the oncolytic activity of H-1PV we performed cell cycle analyses.Results. Previous irradiation rendered glioma cells fully permissive to H-1PV infection. Irradiation 24 hours prior to H-1PV infection led to increased cell killing most notably in radioresistant glioma cells. Intracellular levels of NS-1, the main effector of H-1PV induced cytotoxicity, were elevated after irradiation. S-phase levels were increased one day after irradiation improving S-phase dependent viral replication and cytotoxicity.Conclusion. This study demonstrates intact susceptibility of previously irradiated glioma-cells for H-1PV induced oncolysis. The combination of ionizing radiation followed by H-1PV infection increased viral cytotoxicity, especially in radioresistant gliomas. These findings support the ongoing development of a clinical trial of H-1PV in patients with recurrent glioblastomas.

scholarly journals Chk1 regulates the S phase checkpoint by coupling the physiological turnover and ionizing radiation-induced accelerated proteolysis of Cdc25A

Cancer Cell ◽  
2003 ◽  
Vol 3 (3) ◽  
pp. 247-258 ◽  
Author(s):  
Claus Storgaard Sørensen ◽  
Randi G. Syljuåsen ◽  
Jacob Falck ◽  
Tine Schroeder ◽  
Lars Rönnstrand ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
S Phase ◽  
Radiation Induced ◽  
S Phase Checkpoint

Radiation-induced surface decomposition

1983 ◽  
Vol 41 ◽  
pp. 368-369
Author(s):  
M. L. Knotek
Keyword(s):  
Ionizing Radiation ◽  
Atomic Structure ◽  
Chemical Bonding ◽  
Neutral Species ◽  
Radiation Induced ◽  
Physical And Chemical ◽  
Surface Decomposition ◽  
The Relationship ◽  
Electron And Photon ◽  
Surface Bond

Modern surface analysis is based largely upon the use of ionizing radiation to probe the electronic and atomic structure of the surfaces physical and chemical makeup. In many of these studies the ionizing radiation used as the primary probe is found to induce changes in the structure and makeup of the surface, especially when electrons are employed. A number of techniques employ the phenomenon of radiation induced desorption as a means of probing the nature of the surface bond. These include Electron- and Photon-Stimulated Desorption (ESD and PSD) which measure desorbed ionic and neutral species as they leave the surface after the surface has been excited by some incident ionizing particle. There has recently been a great deal of activity in determining the relationship between the nature of chemical bonding and its susceptibility to radiation damage.

Amifostine-Loaded Dissolving Armored Microneedles for Long-Term Prevention of Ionizing Radiation-Induced Injury

2020 ◽  
Author(s):  
Xiang Yu ◽  
Minshu Li ◽  
Lin Zhu ◽  
Jingfei li ◽  
Guoli Zhang ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Induced

Evaluation of the Radioprotective Effects of Melatonin Against Ionizing Radiation-Induced Muscle Tissue Injury

2019 ◽  
Vol 12 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Dheyauldeen Shabeeb ◽  
Mansoor Keshavarz ◽  
Alireza Shirazi ◽  
Gholamreza Hassanzadeh ◽  
Mohammed Reza Hadian ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Gastrocnemius Muscle ◽  
Tissue Injury ◽  
Histopathological Examination ◽  
Compound Action Potential ◽  
Optimal Dose ◽  
Treatment Method ◽  
Major Product ◽  
Muscle Tissues ◽  
Radiation Induced

Background: Radiotherapy (RT) is a treatment method for cancer using ionizing radiation (IR). The interaction between IR with tissues produces free radicals that cause biological damages.As the largest organ in the human body, the skeletal muscles may be affected by detrimental effects of ionizing radiation. To eliminate these side effects, we used melatonin, a major product secreted by the pineal gland in mammals, as a radioprotective agent. Materials and Methods: For this study, a total of sixty male Wistar rats were used. They were allotted to 4 groups: control (C), melatonin (M), radiation (R) and melatonin + radiation (MR). Rats’ right hind legs were irradiated with 30 Gy single dose of gamma radiation, while 100 mg/kg of melatonin was given to them 30 minutes before irradiation and 5 mg/ kg once daily afternoon for 30 days. Five rats in each group were sacrificed 4, 12 and 20 weeks after irradiation for histological and biochemical examinations. Results: Our results showed radiation-induced biochemical, histological and electrophysiological changes in normal rats’ gastrocnemius muscle tissues. Biochemical analysis showed that malondialdehyde (MDA) levels significantly elevated in R group (P<0.001) and reduced significantly in M and MR groups after 4, 12, and 20 weeks (P<0.001), However, the activity of catalase (CAT) and superoxide dismutase(SOD)decreased in the R group and increased in M and MR groups for the same periods of time compared with the C group (P<0.001), while melatonin administration inverted these effects( P<0.001).Histopathological examination showed significant differences between R group for different parameters compared with other groups (P<0.001). However, the administration of melatonin prevented these effects(P<0.001). Electromyography (EMG) examination showed that the compound action potential (CMAP) value in the R group was significantly reduced compared to the effects in the C and M groups after 12 and 20 weeks (P<0.001). The administration of melatonin also reversed these effects (P<0.001). Conclusion: Melatonin can improve biochemical, electrophysiological and morphological features of irradiated gastrocnemius muscle tissues.Our recommendation is that melatonin should be administered in optimal dose. For effective protection of muscle tissues, and increased therapeutic ratio of radiation therapy, this should be done within a long period of time.

Sign in / Sign up

Export Citation Format

Share Document