X-ray Inactivation of Nuclei as a Method for Studying their Function in the Early Development of Fishes

Development ◽  
1959 ◽  
Vol 7 (2) ◽  
pp. 173-192
Author(s):  
A. A. Neyfakh
Keyword(s):  
Ionizing Radiation ◽  
Early Development ◽  
Nuclear Region ◽  
Blastula Stage ◽  
Early Cleavage ◽  
X Ray ◽  
Male Nucleus ◽  
Cleavage Stages ◽  
Heavy Dose

It is generally accepted at present that during cleavage in echinoderms, amphibians, and fishes, the nuclei do not have specific functions in regulating development, their role being at this time restricted to participation in the processes of cleavage (Schechtman & Nishihara, 1955). Eggs devoid of nuclei sometimes begin cleavage which may proceed up to the stage of the late blastula. Extirpation or inactivation of nuclei may be achieved through the separation of the nuclear region of the egg by means of centrifugation (Harvey, 1940); through extirpation of the female nucleus followed by fertilization with sperm inactivated by a heavy dose of radiation (Briggs, Green, & King, 1951); through spontaneous degeneration of the male nucleus during artificial androgenesis (Stauffer, 1945); and by means of other techniques. Exposure of early cleavage stages in amphibians (Mangold & Peters, 1956; Sanides, 1956) and fishes (Neyfakh, 1956a) to heavy doses of ionizing radiation also leads to arrest of development at the late blastula stage.

Study of the radiomodifier effect of Pityrocarpa moniliformis extract

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
João Victor Torres de Moraes ◽  
Ricardo Luiz Calazans Luna Filho ◽  
Williams Nascimento de Siqueira ◽  
Hianna Arely Milca Fagundes Silva ◽  
Dewson Rocha Pereira ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Cellular Response ◽  
Biomphalaria Glabrata ◽  
Toxicity Tests ◽  
Antioxidant Compounds ◽  
Blastula Stage ◽  
Natural Substances ◽  
60Co Source ◽  
60Co Gamma ◽  
60Co Gamma Radiation

Ionizing radiation has been applied in several areas of knowledge, among them the study of the radiomodifier activity of natural substances. These substances can modify the cellular response to the damage induced by the radiation. Therefore, this work aimed to evaluate the radiomodifier action of Pityrocarpa moniliformis extract on Biomphalaria glabrata embryos exposed to 60Co gamma radiation. Initially, toxicity tests were performed on the extract against the B. glabrata embryos for the choice of concentration that did not cause death and embryonic malformation. Then, the antioxidant activity of the P. moniliformis extract with flavonoids and phenolic compounds was evaluated by means of the ABTS method. To evaluate the radiomodifier activity of the extract, embryos were selected in the blastula stage and irradiated with 7.5 Gy in a 60Co source (gammacell-Co60). Then, the embryos were exposed for 24 h to the extract of P. moniliformis at a concentration of 250 μg/mL. The results showed that the extract of P. moniliformis presents flavonoids and enzymatic inhibition by ABTS, which demonstrates the presence of antioxidant compounds. However, the tests of the radiomodifier activity did not present radioprotective effect for embryos exposed to ionizing radiation.

Requesting physicians’ knowledge of X-radiation exposure from computed tomography scan examinations: A case study of two Nigerian tertiary hospitals

2020 ◽  
Vol 3 ◽  
pp. 36-39
Author(s):  
Samson O. Paulinus ◽  
Benjamin E. Udoh ◽  
Bassey E. Archibong ◽  
Akpama E. Egong ◽  
Akwa E. Erim ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ionizing Radiation ◽  
Ct Scan ◽  
Radiation Exposure ◽  
Work Experience ◽  
Radiation Risk ◽  
Radiological Protection ◽  
X Ray ◽  
Tertiary Hospitals ◽  
Medical Exposure

Objective: Physicians who often request for computed tomography (CT) scan examinations are expected to have sound knowledge of radiation exposure (risks) to patients in line with the basic radiation protection principles according to the International Commission on Radiological Protection (ICRP), the Protection of Persons Undergoing Medical Exposure or Treatment (POPUMET), and the Ionizing Radiation (Medical Exposure) Regulations (IR(ME)R). The aim is to assess the level of requesting physicians’ knowledge of ionizing radiation from CT scan examinations in two Nigerian tertiary hospitals. Materials and Methods: An 18-item-based questionnaire was distributed to 141 practicing medical doctors, excluding radiologists with work experience from 0 to >16 years in two major teaching hospitals in Nigeria with a return rate of 69%, using a voluntary sampling technique. Results: The results showed that 25% of the respondents identified CT thorax, abdomen, and pelvis examination as having the highest radiation risk, while 22% said that it was a conventional chest X-ray. Furthermore, 14% concluded that CT head had the highest risk while 9% gave their answer to be conventional abdominal X-ray. In addition, 17% inferred that magnetic resonance imaging had the highest radiation risk while 11% had no idea. Furthermore, 25.5% of the respondents have had training on ionizing radiation from CT scan examinations while 74.5% had no training. Majority (90%) of the respondents were not aware of the ICRP guidelines for requesting investigations with very little (<3%) or no knowledge (0%) on the POPUMET and the IR(ME)R respectively. Conclusion: There is low level of knowledge of ionizing radiation from CT scan examinations among requesting physicians in the study locations.

Spatial and developmental changes in the respiratory activity of mitochondria in early Drosophila embryos

Development ◽  
1992 ◽  
Vol 115 (4) ◽  
pp. 1175-1182 ◽  
Author(s):  
T. Akiyama ◽  
M. Okada
Keyword(s):  
Respiratory Activity ◽  
Cell Formation ◽  
Rhodamine 123 ◽  
Mitochondrial Activity ◽  
Early Cleavage ◽  
Pole Cell ◽  
Posterior Group ◽  
Cleavage Stages ◽  
Pole Cells ◽  
Drosophila Embryos

Mitochondria of early Drosophila embryos were observed with a transmission electron microscope and a fluorescent microscope after vital staining with rhodamine 123, which accumulates only in active mitochondria. Rhodamine 123 accumulated particularly in the posterior pole region in early cleavage embryos, whereas the spatial distribution of mitochondria in an embryo was uniform throughout cleavage stages. In late cleavage stages, the dye showed very weak and uniform accumulation in all regions of periplasm. Polar plasm, sequestered in pole cells, restored the ability to accumulate the dye. Therefore, it is concluded that the respiratory activity of mitochondria is higher in the polar plasm than in the other regions of periplasm in early embryos, and this changes during development. The temporal changes in rhodamine 123-staining of polar plasm were not affected by u.v. irradiation at the posterior of early cleavage embryos at a sufficient dosage to prevent pole cell formation. This suggests that the inhibition of pole cell formation by u.v. irradiation is not due to the inactivation of the respiratory activities of mitochondria. In addition, we found that the anterior of Bicaudal-D mutant embryos at cleavage stage was stained with rhodamine 123 with the same intensity as the posterior of wild-type embryos. No pole cells form in the anterior of Bic-D embryos, where no restoration of mitochondrial activity occurs in the blastoderm stage. The posterior group mutations that we tested (staufen, oskar, tudor, nanos) and the terminal mutation (torso) did not alter staining pattern of the posterior with rhodamine 123.

Incorporation of Uridine in Cleavage Stage Eggs of the Sea Urchin Paracentrotus Lividus

1971 ◽  
Vol 26 (8) ◽  
pp. 816-821 ◽  
Author(s):  
Larry E. Bockstahler
Keyword(s):  
Ion Exchange ◽  
Sea Urchin ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Paracentrotus Lividus ◽  
Cleavage Stage ◽  
Early Cleavage ◽  
Cell Stage ◽  
Cleavage Stages ◽  
Layer Chromatography

Incorporation of uridine in cleavage stage eggs of the sea urchin Paracentrotus lividus was investigated. It was shown by ion exchange and thin layer chromatography that most of the uridine taken up during the 16-cell stage was converted into UTP with some incorporation into UDP and UMP. Conversion of uridine to these phosphorylated nucleosides occurred throughout early cleavage stages. A very small amount of uridine taken up by cleavage stage eggs is incorporated into RNA heterogeneous in size. This RNA was examined by polyacrylamide gel electrophoresis.

scholarly journals The effect of low LET (Linear Energy Transfer) ionizing radiation to catalase activity of wistar’s submandibular gland

2016 ◽  
Vol 1 (3) ◽  
pp. 145
Author(s):  
Nevy T. Putri ◽  
Sarianoferni Sarianoferni ◽  
Endah Wahjuningsih
Keyword(s):  
Energy Transfer ◽  
Ionizing Radiation ◽  
Submandibular Gland ◽  
Rattus Norvegicus ◽  
Catalase Activity ◽  
Linear Energy Transfer ◽  
Submandibular Salivary Gland ◽  
X Rays ◽  
X Ray ◽  
Bonferroni Test

Intraoral periapical radiograph examination is the additional examination which is the most widely used in Dentistry. This radiograph examination using an x-ray ionizing radiation with low LET (Linear Energy Transfer), and may affect submandibular salivary gland. Ionizing radiation exposure can cause damage by inducing a series of changes at the molecular and cellular level. This study aimed to prove the effects of x-ray ionizing radiation with low LET towards the catalase activity of Rattus norvegicus strain Wistar’s submandibular gland. The subjects were 28 male Wistar rats and divided into 4 groups (n=7). Three groups were exposed 4, 8 and 14 times to radiation with 0.002 µSv for each exposure. The catalase activity of each rat was examined by a spectrophotometer. Data were analyzed using one-way ANOVA followed by Bonferroni test. The results showed the average of catalase activity on Wistar rat’s submandibular gland, respectively for: 0.150±0.0895 (KK), 0.1405±0.0607 (K1), 0.1228±0.0290 (K2), 0.1227±0.0556 (K3). Data showed significant differences of catalase activity between test groups, but showed not significant differences of catalase activity between each groups of Rattus norvegicus strain Wistar’s submandibular gland. In this study concluded decreased catalase activity of Rattus norvegicus strain Wistar’s submandibular gland resulting from x-rays ionizing radiation by 4 times, 8 times and 14 times exposures.

scholarly journals Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

2021 ◽  
Vol 2114 (1) ◽  
pp. 012009
Author(s):  
Thuraya A. Abdul Hussian ◽  
Anwar kh. Farman
Keyword(s):  
Ionizing Radiation ◽  
X Rays ◽  
X Ray ◽  
Beta Particles ◽  
Medical Clinics ◽  
Γ Rays ◽  
Health Laws ◽  
Different Sources ◽  
Α Particles ◽  
Security Procedures

Abstract Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

Determination of the conversion efficiency of X-ray luminophores when measuring the intensity of ionizing radiation

Atomic Energy ◽  
1994 ◽  
Vol 76 (5) ◽  
pp. 390-392 ◽  
Author(s):  
L. P. Gal’chinetskii ◽  
O. N. Zelenskaya ◽  
K. A. Katrunov ◽  
V. D. Ryzhikov
Keyword(s):  
Ionizing Radiation ◽  
Conversion Efficiency ◽  
X Ray

The degree of determination of the early embryo of Schistocerca gregaria (Forskål) (Orthoptera: Acrididae)

Development ◽  
1971 ◽  
Vol 25 (3) ◽  
pp. 277-299
Author(s):  
S. K. Moloo
Keyword(s):  
Early Development ◽  
Schistocerca Gregaria ◽  
Early Embryo ◽  
Germ Band ◽  
Early Cleavage ◽  
Band Formation ◽  
Zygote Nucleus ◽  
Young Embryo ◽  
Blastoderm Stage

The degree of determination of the young embryo of S. gregaria has been investigated using ligation, thermocautery and centrifugation techniques. From the overall results, it is suggested that the early development of the embryo is mediated by two physiological centres. The formation of the germ rudiment is controlled by an activation centre located in the periplasm round the posterior end of the egg. This centre is already present at the zygote nucleus stage and is essential during the very early cleavage period. The differentiation of the germ band is induced by the activity of a second centre, the differentiation centre, located in the presumptive thorax. It apparently becomes established at least by the late blastoderm stage and its activity continues during the period of germ-band formation. During the late cleavage and early blastoderm stages, the egg is labile and the embryo is therefore able to normalize its development after part or parts of the germinal Anlage have been cauterized, removed or displaced. The differentiation centre completes its functions by the beginning of gastrulation. Thereafter, the embryo is determined. The embryo can regulate its size at least up to the gastrulation stage provided that a certain minimum amount of usable yolk is available. The development of the serosa is not under the control of either centre. This structure seems to be capable of regeneration providing that a part of the extra-embryonic blastoderm remains intact.

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