Effects of ionizing radiation on nucleic acids during embryonic development—metabolism during embryogeny and at embryonic tissue level

1968 ◽  
Vol 46 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Chong W. Chang
Keyword(s):  
Embryonic Development ◽  
Nucleic Acids ◽  
Mature Embryo ◽  
Tissue Level ◽  
X Rays ◽  
Tissue Heterogeneity ◽  
X Ray ◽  
Dna And Rna ◽  
X Irradiation ◽  
Different Parts

Observation was made of effects of X-irradiation on DNA and RNA metabolism by means of rates of 32P incorporation into the nucleic acids during barley embryogeny.Levels of disturbances in 32P incorporation rates into DNA caused by X-rays are correlated inversely with the periods of postirradiation and proportionally related to tissue heterogeneity at the time of X-irradiation with the exception of the oldest embryos. Changes in 32P labelling of RNA induced by X-rays during barley embryonic development, however, are independent of the postirradiation periods and differences in the tissue heterogeneity. The levels of differences due to X-rays in 32P incorporation rates into the DNA of the three different regions of a mature embryo reflect the degree of tissue heterogeneity within the embryos at the time of X-ray treatment. Disturbances in the rates of 32P incorporation into DNA are greatest in the root tissue and least in the scutellar region; the shoot part is rated between the levels of the two tissue regions. In contrast, responses of 32P labelling rates of RNA to X-rays in the three different parts of a mature embryo are found to be independent of the tissue heterogeneity at the time of X-ray treatment and the postirradiation period during embryogeny.

Eds Of Radioactive Particles By Self-Induced Fluorescence

1990 ◽  
Vol 48 (2) ◽  
pp. 238-239
Author(s):  
Gregory L. Finch ◽  
Richard G. Cuddihy
Keyword(s):  
Electron Beam Irradiation ◽  
Nuclear Reactor ◽  
X Rays ◽  
Reactor Accident ◽  
Internal Radiation ◽  
X Ray ◽  
External Sources ◽  
X Irradiation ◽  
Available Information ◽  
Individual Particles

The elemental composition of individual particles is commonly measured by using energydispersive spectroscopic microanalysis (EDS) of samples excited with electron beam irradiation. Similarly, several investigators have characterized particles by using external monochromatic X-irradiation rather than electrons. However, there is little available information describing measurements of particulate characteristic X rays produced not from external sources of radiation, but rather from internal radiation contained within the particle itself. Here, we describe the low-energy (< 20 KeV) characteristic X-ray spectra produced by internal radiation self-excitation of two general types of particulate samples; individual radioactive particles produced during the Chernobyl nuclear reactor accident and radioactive fused aluminosilicate particles (FAP). In addition, we compare these spectra with those generated by conventional EDS.Approximately thirty radioactive particle samples from the Chernobyl accident were on a sample of wood that was near the reactor when the accident occurred. Individual particles still on the wood were microdissected from the bulk matrix after bulk autoradiography.

Developmental effects of X-irradiation of early Drosophila embryos

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 253-259
Author(s):  
M. Bownes ◽  
L. A. Sunnell
Keyword(s):  
Early Embryogenesis ◽  
X Rays ◽  
X Ray ◽  
Developmental Effects ◽  
Morphological Defects ◽  
X Irradiation ◽  
Drosophila Embryos ◽  
Adult Cells

Drosophila embryos were treated at specific stages during early embryogenesis with various doses of X-irradiation. The lethality at various times during development was established and pattern defects in the adults noted. It was observed that the most sensitive stages of embryogenesis to X-ray-induced lethality were also the stages where most morphological defects were found in the adults which emerged. This suggests that presumptive larval and adult cells are sensitive to X-rays at the same stages of embryogenesis.

IX. Nucleinsäuregehalt und Nucleinsäuresynthese nach Röntgenbestrahlung

1966 ◽  
Vol 21 (10) ◽  
pp. 960-966 ◽  
Author(s):  
Yasuhiko Takamori ◽  
Ernst-Randolf Lochmann ◽  
Wolfgang Laskowski
Keyword(s):  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Small Difference ◽  
Dry Weight ◽  
Nucleic Acid Content ◽  
X Rays ◽  
X Ray ◽  
Dna And Rna ◽  
High Doses ◽  
Different Doses

The amount of DNA and RNA per dry weight as well as the rate of RNA synthesis was determined in a series of almost isogenic and homozygous Saccharomyces strains of different ploidy which had irradiated with different doses of X-rays.It was found that the RNA content per dry weight showed only a small decrease after irradiation even with high doses. The decrease in the DNA content after irradiation is larger, and it is already maximal at the smallest X-ray dose tested (75 krad) . No further decrease could be observed even after application of 225 krad.The RNA synthesis is much more radioresistant in all strains tested (haploid-hexaploid) than the colony forming ability. X-ray doses which reduce the colony forming ability of the cells to less than 1% lead to a reduction of the RNA synthesis of only about 50 per cent. The inactivation of RNA synthesis increases with increasing irradiation doses and increasing incubation time after irradiation.There was only a small difference in the radiosensitivity of the synthesis of soluble or ribosomal RNA.Genetic effects on the radiation inactivation of the colony forming ability, previously described as “aα-effect” and “AS-effect”, show no influence on the radiosensitivity of cellular nucleic acid content and synthesis.

scholarly journals STUDIES ON THE MECHANISM OF ACTION OF IONIZING RADIATIONS

1952 ◽  
Vol 35 (6) ◽  
pp. 865-871 ◽  
Author(s):  
E. S. Guzman Barron ◽  
S. Louise Seki
Keyword(s):  
Cell Division ◽  
Sperm Cells ◽  
X Rays ◽  
Thiol Compounds ◽  
X Ray ◽  
Arbacia Punctulata ◽  
Inhibiting Effect ◽  
Small Doses ◽  
X Irradiation ◽  
Ionizing Radiations

On x-irradiation of the eggs and sperm of Arbacia punctulata there was inhibition of respiration with relatively large doses, whereas there was an increase with small doses. The dose required to produce an increase of respiration depended on the degree of sensitivity of the cell to the effect of ionizing radiation. Sperm cells were more sensitive; then came fertilized eggs; unfertilized eggs were the least sensitive. The inhibiting effect of x-rays on cell division was observed even on irradiation with x-ray doses which produced an increase of respiration. These results are compared to similar effects produced by thiol reagents and are attributed to oxidation of the thiol compounds in the cell.

scholarly journals Macromolecular crystallography using neutrons

2014 ◽  
Vol 36 (3) ◽  
pp. 40-42
Author(s):  
Matthew Blakeley
Keyword(s):  
Nucleic Acids ◽  
Biological Systems ◽  
Biological Macromolecules ◽  
X Rays ◽  
Macromolecular Crystallography ◽  
X Ray Diffraction ◽  
Vast Array ◽  
X Ray ◽  
Macromolecular Assemblies

When you think about macromolecular crystallography, the technique that most often comes to mind is X-ray diffraction and it's no wonder. Over 88000 structures of biological macromolecules – from proteins and nucleic acids to viruses and macromolecular assemblies – have been determined using X-rays, and these have contributed significantly to our understanding of a vast array of biological systems and processes.

scholarly journals Safety and Functional Integrity of Continuous Glucose Monitoring Components After Simulated Radiologic Procedures

2020 ◽  
pp. 193229682092094 ◽  
Author(s):  
Christopher Thomas ◽  
John B. Welsh ◽  
Spencer Lu ◽  
J. Michael Gray
Keyword(s):  
Magnetic Fields ◽  
Continuous Glucose Monitoring ◽  
Glucose Monitoring ◽  
Data Integrity ◽  
X Rays ◽  
X Ray ◽  
X Irradiation ◽  
Induced Currents ◽  
Displacement Force ◽  
Magnetic Resonance Imaging Mri

Background: We investigated wearable components of the Dexcom G6 continuous glucose monitoring (CGM) System in simulated therapeutic and diagnostic radiologic procedures. Methods: G6 transmitters were loaded with simulated glucose data and attached to sensors. Sets of sensor/transmitter pairs were exposed to x-rays to simulate a radiotherapeutic procedure and to radiofrequency (RF) and magnetic fields to simulate diagnostic magnetic resonance imaging (MRI). The x-ray simulation provided a cumulative dose of 80 Gy. The MRI simulation used RF fields oscillating at 64 or 128 MHz and magnetic fields of 1.5 or 3 T. During the MRI simulation, displacement force, induced heating, and induced currents were measured. After the simulations, bench tests were used to assess data integrity on the transmitters and responsiveness of sensors to various concentrations of aqueous glucose. Results: Glucose concentrations reported by sensor/transmitter pairs after undergoing x-irradiation or a simulated MRI exam were similar to those from control (unexposed) devices. During the 3 T MRI simulation, the devices experienced a displacement force of 306 g, which was insufficient to dislodge the sensor/transmitter from the substrate, RF-induced heating of <2°C, and an induced current of <16 pA. Data stored on the transmitters prior to the MRI simulation remained intact. Conclusion: Wearable components of the G6 CGM System retain basic functionality and data integrity after exposure to simulated therapeutic and diagnostic radiologic procedures. The devices are unlikely to be affected by x-irradiation used in typical imaging studies. Simulated MRI procedures create displacement force, minimal heating, and current in sensor/transmitter pairs.

Resistance to whole-body X-irradiation in rats made tolerant to bacterial endotoxins

1959 ◽  
Vol 197 (6) ◽  
pp. 1364-1370 ◽  
Author(s):  
B. W. Zweifach ◽  
E. Kivy-Rosenberg ◽  
Arnold L. Nagler
Keyword(s):  
Blood Platelet ◽  
Reticuloendothelial System ◽  
Whole Body ◽  
X Rays ◽  
Effective Protection ◽  
X Ray ◽  
E Coli ◽  
Bacterial Endotoxins ◽  
X Irradiation ◽  
Reticulo Endothelial System

Rats were treated with three conditioning agents (bacterial endotoxins, zymosan and compound 48/80) known to produce tolerance to other forms of stress, as a means of determining the importance of the reticulo-endothelial system in the response to WBR. Effective protection was provided by tolerance induced by lipopolysaccharide extracts of E. coli bacteria. Some protection was also afforded by conditioning with 48/80 for several days. These agents were active only when administered before exposure to x-rays. Treatment post x-ray broke down the induced resistance. Blood platelet levels remained high in conditioned animals exposed to WBR. It is suggested that a relationship exists between the priming or conditioning of the reticuloendothelial system and the maintenance of satisfactory blood platelet levels in adapted animals receiving WBR.

scholarly journals Effect of X-ray sterilisation on œstrus in the ferret

1932 ◽  
Vol 109 (764) ◽  
pp. 425-434 ◽  
Keyword(s):  
Guinea Pig ◽  
Species Difference ◽  
X Rays ◽  
Large Follicle ◽  
X Ray ◽  
Complete Obliteration ◽  
X Irradiation

Complete obliteration of the Graafian follicles in the mouse by exposure to X-rays does not suppress the œstrous changes in the uterus and vagina (Parkes, 1926-27; Brambell, Fielding and Parkes, 1927-28; Schugt, 1928; Geller, 1930). It is evident, therefore, that in this animal the actual elaboration of œstrin is not dependent upon the presence of the follicular system. Similar results have been reported on the rat (Ford and Drips, 1929). In the guinea-pig, on the contrary, Genther (1931) finds that the uterine and vaginal changes invariably cease after total obliteration of the follicles. Such of her irradiated animals as showed œstrus all possessed at least one large follicle. In view of the variation in mammalian ovaries, a species difference in the response to X-irradiation might well be expected; in order to investigate this point, experiments were begun two years ago on an animal with a type of ovary and cycle distinct from that of the mouse, i. e ., the ferret. The results are described below.

THE HYPOPHYSIAL CONTROL OF THE X-RAY STERILIZED OVARY

1958 ◽  
Vol 17 (1) ◽  
pp. 1-12 ◽  
Author(s):  
D. L. INGRAM ◽  
ANITA M. MANDL
Keyword(s):  
Stromal Cells ◽  
The Other ◽  
Vaginal Smear ◽  
X Rays ◽  
Adult Rats ◽  
X Ray ◽  
Uterine Involution ◽  
Other Hand ◽  
X Irradiation

SUMMARY Adult rats which had been previously sterilized by means of X-rays were hypophysectomized a fortnight after the onset of continuous vaginal cornification (which begins within 40 days of X-irradiation [Mandl & Zuckerman, 1956]). The animals, including non-irradiated hypophysectomized controls, were killed at periods of 5–70 days after hypophysectomy. Cornified cells disappeared from the vaginal smear of non-irradiated rats within 3, and of irradiated rats within 4 days after hypophysectomy. The ovaries involuted rapidly in both groups of animals. Stromal cells decreased in size and post-hypophysectomy 'deficiency cells' appeared. On the other hand, the rate of uterine involution was slower in the X-irradiated animals after hypophysectomy than in the non-irradiated hypophysectomized controls. This finding indicates that in the absence of the pituitary, the X-irradiated ovary can produce more oestrogen than a non-irradiated ovary, or that the oestrogen it produces is biologically more active. After treatment with gonadotrophin, the 'deficiency cells' in the ovaries of both groups of animals disappeared. The X-irradiated hypophysectomized animals responded to the gonadotrophin less vigorously (as judged by an increase in ovarian and uterine size) than did the hypophysectomized controls.

scholarly journals MUTANTS PRODUCED BY X-IRRADIATION OF SPORES OF CHAETOMIUM GLOBOSUM AND A COMPARISON WITH THOSE PRODUCED BY ULTRAVIOLET IRRADIATION

1949 ◽  
Vol 32 (6) ◽  
pp. 647-653 ◽  
Author(s):  
J. M. Ford ◽  
D. P. Kirwan
Keyword(s):  
Ultraviolet Irradiation ◽  
Wave Length ◽  
Fungal Spores ◽  
Chaetomium Globosum ◽  
Theoretical Curve ◽  
Striking Difference ◽  
X Rays ◽  
X Ray ◽  
Large Numbers ◽  
X Irradiation

1. Mutants produced by x-irradiation of fungal spores of Chaetomium globosum have been compared with those produced by ultraviolet irradiation. 2. The most striking difference between the mutants produced by x-irradiation and ultraviolet irradiation is the absence in x-ray experiments of the K mutant which is produced in large numbers at short ultraviolet wave lengths. 3. A comparison is made of the relation between x-ray dose and numbers of lethal mutants, and the relation between the short ultraviolet wave length 2804 dose and numbers of lethal mutants. Both are compared with theoretical curves for 1, 2, 5, and 8 quantum hits. 4. The production of lethal mutants by x-rays is shown to be consistent with the theoretical curve for five quantum hits on the sensitive spot of the spore, whereas the production of lethal mutants by the ultraviolet wave length 2804 Å.u. is consistent with two quantum hits.

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