Repair of pyrimidine dimers in radiation-sensitive mutants rad3, rad4, rad6, and rad9 of Saccharomyces cerevisiae. [nicking

Energy Technology Data Exchange (ETDEWEB)

Prakash, L [Rochester Univ., N.Y. (USA). Dept. of Radiation Biology and Biophysics; Rochester Univ., N.Y. (USA). School of Medicine and Dentistry)

1977-10-01

The ability to remove ultraviolet-induced pyrimidine dimers was examined in four radiation-sensitive mutants of Saccharomyces cerevisiae. The susceptibility of DNA from irradiated cells to nicking by either the T4 uv-endonuclease or an endonuclease activity found in crude extracts of Micrococcus luteus was used to measure the presence of dimers in DNA. The rad3 and rad4 mutants are shown to be defective in dimer excision whereas the rad6 and rad9 mutants are proficient in dimer excision.

Experience with the biofragmentable anastomotic ring (BAR) in bowel preoperatively irradiated with 6000 rad

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Croston, J.K.; Jacobs, D.M.; Kelly, P.H.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Bubrick, M.P. (Hennepin County Medical Center, Minneapolis, MN (USA))

1990-03-01

Previous studies from the authors' laboratory using the biodegradable anastomotic ring (BAR) have demonstrated the safety of this device in animals irradiated preoperatively with the equivalent of 5000 rad; sutured, stapled, and BAR anastomoses all had leak rates of 10 percent or less in this setting. This study was undertaken to assess the safety of the BAR after irradiation with the equivalent of 6000 rad. Thirteen mongrel dogs underwent preoperative irradiation to the rectum and rectosigmoid, receiving 6000 rad according to the nominal standard dose equation. After a three-week rest period, each dog underwent anterior resection of the rectosigmoid and anastomosis with the BAR. The anastomoses were evaluated for early and late healing and anastomotic leaks. The results were compared with previous data from the authors' laboratory using an identical model. Radiographic leaks were found in 7 of 10 sutured anastomoses, 8 of 10 stapled anastomoses, and 3 of 13 BAR anastomoses (P less than 0.01). Comparative clinical leaks were 5 of 10 for sutured, 5 of 10 for stapled, and 3 of 13 for BAR anastomoses. These data suggest that the BAR may offer added safety to an anastomosis after preoperative irradiation. Whether this effect is due to the atraumatic technique of placing the device, improved blood flow to the anastomotic margins, or other factors, is still underdetermined.

Experience with the biofragmentable anastomotic ring (BAR) in bowel preoperatively irradiated with 6000 rad

International Nuclear Information System (INIS)

Croston, J.K.; Jacobs, D.M.; Kelly, P.H.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Bubrick, M.P.

1990-01-01

Previous studies from the authors' laboratory using the biodegradable anastomotic ring (BAR) have demonstrated the safety of this device in animals irradiated preoperatively with the equivalent of 5000 rad; sutured, stapled, and BAR anastomoses all had leak rates of 10 percent or less in this setting. This study was undertaken to assess the safety of the BAR after irradiation with the equivalent of 6000 rad. Thirteen mongrel dogs underwent preoperative irradiation to the rectum and rectosigmoid, receiving 6000 rad according to the nominal standard dose equation. After a three-week rest period, each dog underwent anterior resection of the rectosigmoid and anastomosis with the BAR. The anastomoses were evaluated for early and late healing and anastomotic leaks. The results were compared with previous data from the authors' laboratory using an identical model. Radiographic leaks were found in 7 of 10 sutured anastomoses, 8 of 10 stapled anastomoses, and 3 of 13 BAR anastomoses (P less than 0.01). Comparative clinical leaks were 5 of 10 for sutured, 5 of 10 for stapled, and 3 of 13 for BAR anastomoses. These data suggest that the BAR may offer added safety to an anastomosis after preoperative irradiation. Whether this effect is due to the atraumatic technique of placing the device, improved blood flow to the anastomotic margins, or other factors, is still underdetermined

Effect of low level prenatal X-irradiation on postnatal growth in the Wistar rat

International Nuclear Information System (INIS)

Jensh, R.P.; Brent, R.L.

1988-01-01

Forty-five pregnant Wistar strain rats were exposed to 0.0, 0.4, 0.6, or 0.8 Gy X-radiation on the 9th or 17th day of gestation to determined if prenatal X-irradiation would result in alterations in postnatal growth or growth rate. The mothers delivered their offspring, and the litters were reduced to a maximum of eight per litter on the second postnatal day. The 336 offspring were weighed weekly from day 3 until day 86, at which time they were killed, an autopsy was performed, and selected organs were removed and weighed. Postnatal growth rates did not differ significantly in irradiated offspring compared to sham irradiated animals. Irradiation on the 9th day, at any of the 3 dosage levels, did not result in significant differences in weekly weight. Weekly weight remained significantly lower due to irradiation on the 17th day of gestation. The gonadal weight ratio was significantly reduced in males irradiated on the 9th day. There were not other statistically significant changes in organ weight or organ/body weight ratios due to these levels of prenatal X-irradiation on the 9th or 17th day of pregnancy. These results indicate that low level prenatal X-irradiation, on the 17th day of rat gestation, causes prenatal growth retardation, evident at birth, which is not recuperable postnatally. Exposure to x-radiation at this time, however, does not affect the rate at which offspring grow during postnatal life. Offspring are smaller because they never fully recover from the original radiation-induced prenatal growth retardation

Effects of low-dose prenatal irradiation on the central nervous system

International Nuclear Information System (INIS)

1992-04-01

Scientists are in general agreement about the effects of prenatal irradiation, including those affecting the central nervous system (CNS). Differing concepts and research approaches have resulted in some uncertainties about some quantitative relationships, underlying interpretations, and conclusions. Examples of uncertainties include the existence of a threshold, the quantitative relationships between prenatal radiation doses and resulting physical and functional lesions, and processes by which lesions originate and develop. A workshop was convened in which scientists with varying backgrounds and viewpoints discussed these relationships and explored ways in which various disciplines could coordinate concepts and methodologies to suggest research directions for resolving uncertainties. This Workshop Report summarizes, in an extended fashion, salient features of the presentations on the current status of our knowledge about the radiobiology and neuroscience of prenatal irradiation and the relationships between them

Effects of low-dose prenatal irradiation on the central nervous system

Energy Technology Data Exchange (ETDEWEB)

1992-04-01

Scientists are in general agreement about the effects of prenatal irradiation, including those affecting the central nervous system (CNS). Differing concepts and research approaches have resulted in some uncertainties about some quantitative relationships, underlying interpretations, and conclusions. Examples of uncertainties include the existence of a threshold, the quantitative relationships between prenatal radiation doses and resulting physical and functional lesions, and processes by which lesions originate and develop. A workshop was convened in which scientists with varying backgrounds and viewpoints discussed these relationships and explored ways in which various disciplines could coordinate concepts and methodologies to suggest research directions for resolving uncertainties. This Workshop Report summarizes, in an extended fashion, salient features of the presentations on the current status of our knowledge about the radiobiology and neuroscience of prenatal irradiation and the relationships between them.

Effects of 4000 rad irradiation on the in vitro storage properties of packed red cells

International Nuclear Information System (INIS)

Moore, G.L.; Ledford, M.E.

1985-01-01

Immunosuppressed patients who require red cell transfusions receive irradiated (1500-3000 rad) packed red cells. These cells are irradiated immediately before infusion. If a large group of patients become immunosuppressed due to exposure to radiation or chemicals, the ability to supply large volumes of irradiated blood at the time of use might not be possible. An alternate solution to providing quantities of irradiated blood is to irradiate the units prior to storage. This study presents in vitro data comparing storage of paired packed red cell units either irradiated or not irradiated. Five units of fresh blood drawn into citrate-phosphate-dextrose-adenine (CPDA-1) were packed to a hematocrit of 75 +/- 1 percent, and then each unit was divided in two equal parts. One of each pair was irradiated (4000 rads), and both parts of each unit were stored for 35 days at 4 degrees C. Samples were analyzed every 7 days. Irradiation caused a slight drop in red cell adenosine triphosphate and 2,3 diphosphoglycerate and a slight increase in plasma hemoglobin compared to controls. Methemoglobin, pH, and glucose consumption were identical to the controls. The evidence indicates that irradiation did not cause biochemical or metabolic changes in the red cells that would lead us to suspect a difference between irradiated and nonirradiated stored red cells in function or viability. These negative findings require in vivo confirmation

Biogenic amines, amino acids and regional blood flow in rat brain after prenatal irradiation

International Nuclear Information System (INIS)

Deroo, J.; Gerber, G.B.; Maes, J.

1986-01-01

Damage to nerve cells after prenatal irradiation could affect their later ability to function normally. The concentration of several biogenic amines and amino acids was therefore determined at different times after prenatal irradiation with 0.95 Gy on day 10, 12 or 15 of pregnancy. The offspring was sacrified 0.5, 1, 3 and 6 months after birth and the following structures were dissected: Cortex, hippocampus, striatum, thalamus, hypothalamus, cerebellum and medulla. Biogenic amines isolated by HPLC and detected electrochemically were: Dopamine, DOPA, DOPAC, epinephrine, norepinephrine, serotonin and hydroxyindolacetate. Amino acids converted to their dansyl derivatives and separated by HPLC were: Aspartate, glutamate, glutamine, gamma aminobutyrate and taurine. Many neurotransmitters were found increased in brain after prenatal irradiation, particularly on day 12 and 15 p.c. Marked changes were found for serotonin in several brain structures and for dopamin in striatum. An increase was also found in glutamate, glutamine and GABA. Studies on regional blood flow using injection of labelled 15 μ microspheres did not reveal significant alterations after prenatal irradiation. (orig.)

Effect of prenatal irradiation on total litter birth weight

International Nuclear Information System (INIS)

Angleton, G.M.; Lee, A.C.

1981-01-01

Total litter weight at birth was used as a response variable to study the effects of in utero irradiations on birth weight. Analyses were performed in such a manner as to allow for variations in litter size and environmental temperatures. No effects due to irradiation were noted for exposures given 8 days postcoitus (dpc) and 55 dpc. However, for exposures given 28 dpc, a 5% decrement in birth weight was found for an 80 rad dose

Prenatal irradiation: radioinduced apoptosis in developing central nervous system

International Nuclear Information System (INIS)

Gisone, P.; Dubner, D.; Michelin, S.; Perez, M.R.; Barboza, M.

1998-01-01

Severe mental retardation (SMR) is the most significant effect of prenatal irradiation. The high radiosensitivity of developing brain is related with the chronology of morpho genetic phenomena regarding neuroblast proliferation, neuronal differentiation and migration, synaptogenesis and dendritic arborization. Programmed cell death (apoptosis) normally occurs during development in central nervous system (CNS). Apoptosis is a direct result of the expression of specific genes with a final common pathway leading to a characteristic DNA fragmentation pattern. A wide variety of situations and toxic agents have been reported to result in apoptotic death in developing CNS. The aim of this work was the characterization and quantification of apoptosis using an in vitro model of prenatal irradiation. Primary cell cultures from rat brain cortex of 17 days g.a. were irradiated with a gamma source, with doses between 0.2 Gy to 2 Gy. Apoptosis was evaluated 4 hours and 20 hours after irradiation by hematoxylin/eosin, fluorescent microscopy, flow cytometry and DNA electrophoresis. It was also evaluated the neuro protective effect of L-NAME, SOD and glutathion. A dose-dependent increase in apoptotic cell fraction was observed. A protector effect related with the presence of glutathion was observed. (author) [es

Preferential binding of yeast Rad4-Rad23 complex to damaged DNA

International Nuclear Information System (INIS)

Jansen, L.E.T.; Verhage, R.A.; Brouwer, J.

1998-01-01

The yeast Rad4 and Rad23 proteins form a complex that is involved in nucleotide excision repair (NER). Their function in this process is not known yet, but genetic data suggest that they act in an early step in NER. We have purified an epitope-tagged Rad4.Rad23 (tRad4. Rad23) complex from yeast cells, using a clone overproducing Rad4 with a hemagglutinin-tag at its C terminus. tRad4.Rad23 complex purified by both conventional and immuno-affinity chromatography complements the in vitro repair defect of rad4 and rad23 mutant extracts, demonstrating that these proteins are functional in NER. Using electrophoretic mobility shift assays, we show preferential binding of the tRad4.Rad23 complex to damaged DNA in vitro. UV-irradiated, as well as N-acetoxy-2-(acetylamino)fluorene-treated DNA, is efficiently bound by the protein complex. These data suggest that Rad4.Rad23 interacts with DNA damage during NER and may play a role in recognition of the damage

Brain anomalies induced by gamma irradiation in prenatal period

International Nuclear Information System (INIS)

Schmidt, S.L.

1992-01-01

Gamma irradiation has been utilized in order to produce cortical and callosal abnormalities. We have also checked for the presence of the aberrant longitudinal bundle in the brains of mice born acallosal due to prenatal irradiation is also checked. Pregnant mice were exposed to gamma irradiation from a 6 0 Co source at 16, 17 and 19 days of gestational age (E 16, E 17 and E 19) with total doses of 2 Gy and 3 Gy. At 60 days postnatal the offspring of irradiated animals were intra cardiac perfused, the brains were removed from the cranio and cut into coronal or para sagittal sections. (author)

Regeneration of CFUs in the marrow of mice exposed to 300 rads after having recovered from 950 rads

International Nuclear Information System (INIS)

Kedo, A.; Barone, J.; Fried, W.

1976-01-01

Exposure to 950 rads 60 Co radiation has been reported to cause long-lasting damage to the hematopoietic stroma (HS), although the size of the CFUs population recovers to pre-irradiation levels. In these studies HS damage was detected only after subcutaneously implanting the femurs of the irradiated mice into syngeneic hosts. To exclude the possibility that what was considered to be HS damage was merely caused by artifacts due to the process of implantation in a new host, the rate of regeneration of CFUs in mice which had recovered from 950 rads prior to receiving 300 rads 60 Co radiation (950 + 300 rads group) was compared with that of mice which received only 300 rads (0 + 300 rads group). The CFUs population in the 950 + 300 rads group grew exponentially for 2 weeks at a rate which did not differ significantly from that of CFUs in the 0 + 300 rads group. However, the rate of CFUs growth reached a plateau before full recovery was achieved in contrast to that in the 0 + 300 rads mice. It was therefore concluded that the incomplete regeneration of CFUs in the marrows of 950 + 300 rads mice was most likely caused by X-irradiation-induced damage to the HS rather than damage to the inherent repopulation potential of the CFUs per se. (author)

Cytofluorometric analysis of proliferation kinetics of cerebral cells of prenatally irradiated rats

International Nuclear Information System (INIS)

Borovitskaya, A.E.; Evtushenko, V.I.; Tokalov, S.V.; Yagunov, A.S.; Khanson, K.P.

1994-01-01

Prenatal irradiation of humans or animals causes serious and life-long functional and structural damage to the central nervous system. Irradiation of a fetus decreases its brain mass, an effect accompanied by a broad spectrum of disorders in higher nervous activity and behavior. The extent of cerebral damage depends on the kind of radiation, dosage, and on the stage of embryonic development. In rodents, the most serious damage resulted from the irradiation of 15-18 day embryos. Prenatally irradiated animals had pronounced morphological and biochemical changes within the brain, as well as serious deviations from normal behavior. The cerebral structural-functional disorders are known to result from the destruction of irradiated cells, primarily of neuroblasts. The authors used flow cytofluorometry to study the proliferation of cerebral cells at various ontogenetic stages in rats antenatally exposed to γ-neutron radiation. For one-week old animals, the postradiation changes of cell distributions over the cell cycle were found only within the cerebellum. This likely reflects the compensatory cell proliferation, because delayed postnatal development is typical of this part of the brain. There were no detectable differences in brain cytokinetics between two week-old control and irradiated animals. Most of the brain cells (except a limited population of glia, endothelial cells, and cells of the secondary germinal layer) are in the resting state during this period, and radiation does not change their cell cycle distributions. Thus, the increasing occurrence of the S + G 2 + M phases in the cell cycle observed in newborn irradiated rats may reflect the enhanced proliferation of nervous cells surviving the irradiation. However, this compensatory proliferation does not prevent the brain mass from being deficient in the postnatal development of prenatally irradiated animals

Human RAD18 interacts with ubiquitylated chromatin components and facilitates RAD9 recruitment to DNA double strand breaks.

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Akiko Inagaki

Full Text Available RAD18 is an ubiquitin ligase involved in replicative damage bypass and DNA double-strand break (DSB repair processes. We found that RPA is required for the dynamic pattern of RAD18 localization during the cell cycle, and for accumulation of RAD18 at sites of γ-irradiation-induced DNA damage. In addition, RAD18 colocalizes with chromatin-associated conjugated ubiquitin and ubiquitylated H2A throughout the cell cycle and following irradiation. This localization pattern depends on the presence of an intact, ubiquitin-binding Zinc finger domain. Using a biochemical approach, we show that RAD18 directly binds to ubiquitylated H2A and several other unknown ubiquitylated chromatin components. This interaction also depends on the RAD18 Zinc finger, and increases upon the induction of DSBs by γ-irradiation. Intriguingly, RAD18 does not always colocalize with regions that show enhanced H2A ubiquitylation. In human female primary fibroblasts, where one of the two X chromosomes is inactivated to equalize X-chromosomal gene expression between male (XY and female (XX cells, this inactive X is enriched for ubiquitylated H2A, but only rarely accumulates RAD18. This indicates that the binding of RAD18 to ubiquitylated H2A is context-dependent. Regarding the functional relevance of RAD18 localization at DSBs, we found that RAD18 is required for recruitment of RAD9, one of the components of the 9-1-1 checkpoint complex, to these sites. Recruitment of RAD9 requires the functions of the RING and Zinc finger domains of RAD18. Together, our data indicate that association of RAD18 with DSBs through ubiquitylated H2A and other ubiquitylated chromatin components allows recruitment of RAD9, which may function directly in DSB repair, independent of downstream activation of the checkpoint kinases CHK1 and CHK2.

A forecast of the thyroid pathology at the children irradiated prenatally

International Nuclear Information System (INIS)

Akulich, N.S.

1995-01-01

It is investigated a state of the hypophysis thyroid system at 44 pregnant women in age 19-36 years, which were irradiated by low dozes during the Chernobyl NPP accident and evacuated from the contaminated zone in first 10 days. The average doze of internal irradiation of the thyroid for pregnant women is equal 4,374 +- 1,364 mGy and for irradiated prenatally children -5,283 +- 1,454 mGy. The researches of free thyroxine, triiodothyronine and thyroxine binding globulin were done by the radiation immunological method in a venous blood serum, and a thyrotropic hormone - by a set of the 'CIS Bio International' firm. The diagnosis of the thyroid pathology was confirmed by a ultrasonic research and determination of contents of thyroid hormones. The account of the internal irradiation dozes for a thyroid was conducted by means of a use of a single exponential model of a removing of iodine 131. The fetus' thyroid irradiation doze owing to a entering of radioisotopes to the mother's body was estimated by means of the dose rate on the basis of the Johnson three component model. Direct correlation between the thyroid function at pregnant women, which were irradiation by low doses, and frequency of occurrence of an endemic goiter at the children irradiated prenatally is established. At the contents of the free thyroxine 128,9 +- 4,8 nmol/l or more, triiodothyronine 1,9 +- 0,2 nmol/l or less and increase of an activity of thyrotropic hormone from 1,3 +- 0,1 μU/ml in 12 - 27 weeks of pregnancy up to 1,9 +- 0,2 μU/ml in 38-40 weeks it is possible to predict an occurrence of the thyroid pathology at the future child. Is offered to use from the 12-weak term of pregnancy a radiation immunological method of research of thyrotropic and thyroid hormones of pregnant women, subjected to radiation effect, for preventive maintenance and revealing of early disorders of a thyroid at the children irradiated prenatally. 10 refs., 1 tab

Radiation effects on pre-natal development and their radiological significance

International Nuclear Information System (INIS)

Mole, R.H.

1979-01-01

The evidence relating to pre-natal radiation exposure and the subsequent occurrence of malformations and cancer suggests that the overall risk lies in the range 0 to 1 cases per 1000 irradiated by one rad in utero in the first four months of pregnancy. The natural level of occurrence of serious handicaps in average pregnancies is at least 30 times higher. Is the much lower probability of radiation-induced harm sufficiently high to justify (a) concern when a woman who has been irradiated is found to have been pregnant at that time, or (b) the maintenance of restrictions on medical uses of ionizing radiation in women in the reproductive age, such as the ten day rule. (author)

Ionizing radiation and the conceptus: neurophysiologic effects of prenatal X-radiation on offspring

International Nuclear Information System (INIS)

Jensh, R.P.

1985-01-01

A brief review of the literature precedes the presentation of a radiation behavioral teratology study. The various types of radiation and the units of measure used in radiation biology are discussed. The concept of the radiation-induced teratogenic ''triad'' of growth retardation, malformation, and death is presented. A discussion of stage- and dose-dependent sensitivity to prenatal irradiation is followed by an introduction to behavioral teratology as a new interdisciplinary area of investigation, emphasizing postnatal psychophysiologic analyses of the effects of prenatal exposure. In the present study, rats were exposed to an acute dosage level of 0.6 Gy (60 RAD) X-radiation on day 9 or 17 of gestation. The neonates were given five neonatal reflex tests, observed for the appearance of four physiologic markers, and, as young adults, subjected to three of six behavioral tests. The irradiated offspring exhibited retarded postnatal growth and altered reflex and behavioral activity. These results indicate that irradiation at a dosage level which does not cause overt morphologic malformations at birth does result in altered postnatal growth and psychophysiologic development

Effects of prenatal 60Co irradiation on postnatal neural, learning, and hormonal development of the squirrel monkey

International Nuclear Information System (INIS)

Ordy, J.M.; Brizzee, K.R.; Dunlap, W.P.; Knight, C.

1982-01-01

The goals of this study were to examine the effects of 0, 50, and 100 rad of 60 Co administered prenatally on postnatal development of neuromuscular coordination, visual discrimination learning, spontaneous light-dark stabilimeter activity, plasma cortisol, and somatometric growth rates of diurnal squirrel monkeys from birth to 90 days. In terms of accuracy, completeness, and time required for performance of reflexes and neuromuscular coordination, the performance of 50- and 100-rad offspring was less accurate and poorly coordinated and required more time for completion to that of controls. In visual orientation, discrimination, and reversal learning, the percentage correct responses of the 50- and 100-rad offspring were significantly lower than those of controls. Spontaneous light-dark stabilimeter activity of 50- and 100-rad offspring was significantly higher in the dark session than that of controls. Plasma cortisol was significantly higher in 100-rad infants than in controls. Comparisons of somatometric growth rates indicated that postnatal head circumference, crown-rump length, and to a lesser extent body weight increased at significantly slower rates in 50- and 100-rad offspring. These findings should provide essential information for formulating and carrying out multivariate behavioral, biochemical, and morphometric assessments of low-dose effects on the brain of primate offspring within demonstrable dose-response curves

Effects of continuous prenatal γ radiation on the pig and rat

International Nuclear Information System (INIS)

Erickson, B.H.; Martin, P.G.

1976-01-01

Little is known of the effects of continuous low-level irradiation applied prenatally to the long-lived mammal. As compared with the rodent, developmental events are protracted in long-lived species and consequently are at risk longer. Estimation of radiation risk to man therefore requires data from animals in which developmental events are similarly protracted. Pigs were irradiated continuously for the first 108 days of their 112-day gestation period at rates of 20, 9, 3 and 1.5 R per 22-hour day. Six pregnant gilts and six controls were employed at each dose rate. Foetal doses were 7, 3, 1 and 0.5 rad/d. Neither the health of the gilt nor the number of live births was affected by any exposure. Postnatal viability was also unaffected. Radiation effects on growth and organic development were assayed at birth, 70 and 150 days of age. Body weight and growth were unaffected by dose rates of 3 rad/d or less; and other than the gonad, only the weight of the brain was affected by 3 rad/d. At 1 rad/d or less only gonadal weight was reduced. The most spectacular finding at doses of 7 and 3 rad/d was sterility in both sexes. Following 1 rad/d, germ-cell number was reduced to 5% and 2% of control in the female and male, respectively. At 0.5 rad/d/, germ cells were reduced to 43% of control in the female and 11% of control in the male. In contrast to the pig, 7 rad/d reduced the germ-cell population of male and female rats to only 49% and 35% of control, respectively, and 1 rad/d produced no apparent effect in either sex. It appears, therefore, that interspecific differences in the response to continuous γ radiation are large and that the germ cell is the most labile cell type. (author)

Comparable effects of 1800- and 2400-rad (18- and 24-Gy) cranial irradiation on height and weight in children treated for acute lymphocytic leukemia

International Nuclear Information System (INIS)

Starceski, P.J.; Lee, P.A.; Blatt, J.; Finegold, D.; Brown, D.

1987-01-01

To examine the effects of low-dose cranial irradiation on growth and to determine if one can predict patients in whom growth will be most affected, we studied 47 children with acute lymphocytic leukemia who had been treated with 2400 rad (24 Gy), 1800 rad (18 Gy), or no whole-brain irradiation. Serial measurements of height, weight, and weight for height were obtained by retrospective chart review. The effects of 1800 rad (18 Gy) and 2400 rad (24 Gy) treatment were indistinguishable. Height percentiles among irradiated patients decreased by a mean of 12% six months after diagnosis, and growth generally did not catch up. Moreover, although 33 irradiated patients maintained heights within the normal range, In 11 patients (33%) a dramatic falloff occurred such that by three years following diagnosis their height for age was more than 30 percentiles below the original value. These patients were all identifiable at six months since their height percentiles had already decreased by more than 15%. Although weight percentiles did not change following irradiation, the weight-for-height ratio increased and patients were relatively stockier three years after therapy than they had been at diagnosis. In patients who had received chemotherapy alone, the weight-for-height ratio also increased, but this appeared to be due to a disproportionate increase in weight. Longer follow-up and evaluation of larger cohorts of patients treated with 1800 rad (18 Gy) will be needed to confirm these results

Ontogenetic changes in the ultrastructure of rat hepatocyte organelles after prenatal x irradiation

International Nuclear Information System (INIS)

Chedid, A.; Nair, V.

1975-01-01

The effects of prenatal x irradiation on the development of hepatocyte organelles have been studied in Sprague-Dawley rats. Pregnant rats received 50 R to the pelvic region on the 13th gestation day (g.d.). Animals were sacrificed on g.d.'s 15 and 20, day of birth, and 5th postnatal day. The fetal and neonatal livers were obtained and processed for electron-microscopic examination. The most striking discernible change after irradiation involves the appearance of cytoplasmic ''polyribosomal aggregates'' in the hepatocyte specimens of 15th and 20th g.d.'s. In the control rat, smooth endoplasmic reticulum (SER) appears for the first time on 20th g.d., while no SER could be detected in the hepatocytes from the irradiated animals at this period nor on day of birth. In the irradiated animals, SER was observed on the 5th postnatal day. Our results are consistent with the hypothesis that lipid peroxidation membrane alteration, delayed appearance of SER, and ''polyribosomal aggregation'' may be sequentially linked events after prenatal x irradiation. (U.S.)

The disturbances of lipid metabolism regulation after the prenatal low-level irradiation

International Nuclear Information System (INIS)

Rogov, Yu.I.; Danil'chik, V.S.; Spivak, L.V.; Rubchenya, I.N.

2000-01-01

The objective of this study was to assess the influence of low-level irradiation on lipid metabolism in rats after prenatal exposure. Pregnant rats were irradiated during the period of gestation with the whole final dose 0,5 Gy/rat. The blood lipid fractions were investigated in newborn rats and in 6-month age rats. In irradiated offspring the lipo synthesis processes exceeded lipolysis in comparison with that of the control. The negative consequences of embryo low-level irradiation in the lipid metabolism regulation are discussed in this report. (authors)

Correlation of RAD51 and radiosensitization of methotrexate

International Nuclear Information System (INIS)

Du Liqing; Bai Jianqiang; Liu Qiang; Wang Yan; Zhao Peng; Chen Fenghua; Wang Hong; Fan Feiyue

2012-01-01

Objective: To evaluate the correlation between homologous recombination repair protein RAD51 and methotrexate-enhanced radiosensitivity. Methods: Western blot and RT-PCR assays were used to detect RAD51 expression in HOS osteosarcoma cells exposed to γ-ray irradiation alone and in combination with methotrexate. Colony formation assay was used to test the survival fraction of HOS cells exposed to γ-rays and methotrexate. Results: Methotrexate inhibited both protein and RNA expressions of RAD51, and the combination of radiation and methotrexate enhanced the inhibition of RAD51 expression. Moreover, transfection of cells with RAD51 gene decreased cellular sensitivity to methotrexate and γ-rays. The sensitizer enhancement ratios after irradiation in combination with methotrexate were 1.51 and 0.99, respectively. Methotrexate was a preferred radiosensitizer to HOS cell. Conclusions: RAD51 might be involved in the methotrexate-enhanced radiosensitivity. (authors)

Biological effects of prenatal irradiation

International Nuclear Information System (INIS)

Streffer, Christian

1997-01-01

After large releases of radionuclides, exposure of the embryo or fetus can take place by external irradiation or uptake of radionuclies. The embryo and fetus are radiosensitive throughout prenatal development. The quality and extent of radiation effects depend on the development stage. During the preimplantation period (one to 10 days postconception, p.c.) a radiation exposure of at least 0.2 Gy can cause the death of the embryo. Malformations are only observed in rare cases when genetic predisposition exist. Macroscopic, anatomical malformations are induced only after irradiation during the major organogenesis (two to eight weeks p.c.). A radiation dose of about 0.2 Gy is a doubling dose for the malformation risks as extrapolated from experiments with rodents. The human embryo may be more radioresistant. During early fetogenesis (8-15 weeks p.c.) a high radiosensitivity exists for the developmental of the brain. Radiation doses of 1.0 Gy cause severe mental retardation in about 40% of the exposed fetuses. It must be taken into account that a radiation exposure during the fetal period can also induce cancer. It is generally assumed that the risk exists at about the same level as for children. (Author)

Fertility and irradiation: a preconceptional investigation in teratology

International Nuclear Information System (INIS)

Philippe, J.V.

1975-01-01

The effects of preconceptional irradiation on female fertility were investigated in six groups of 35 nulliparous Swiss-Webster mice whole-body irradiated with single doses of 25, 50, 75, 100, 150, and 300 rads of 60 Co. They were mated with nontreated males and killed on gestational day 18. The litters were recorded in the chronologic order of their occurrence within each group. The percentage of pregnancies decreased with the dose, while the prenatal loss increased. Up to 100 rads, the middle group of pregnancies was devoid of resorptions, fetal death, and congenital anomalies, thus giving rise to a ''maximum viability enclave.'' Beyond this level those three adverse effects were more or less homogeneously distributed over the whole period for which pregnancies were recorded. Exencephaly, microcephaly, and eye defects were the most frequent malformations. Among other sequelae, hypertrophy of the higher pole occurred in the left kidney in the surviving infertile females killed 5 months after treatment

HiRadMat: A high‐energy, pulsed beam, material irradiation facility

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Charitonidis, Nikolaos

2016-01-01

HiRadMat is a facility constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where different material samples or accelerator components can be tested. The facility, located at the CERN SPS accelerator complex, uses a 440 GeV proton beam with a pulse length up to 7.2 μs and a maximum intensity up to 1E13 protons / pulse. The facility, a unique place for performing state-of-the art beam-to-material experiments, operates under transnational access and welcomes and financially supports, under certain conditions, experimental teams to perform their experiments.

Life shortening and carcinogenesis in mice irradiated at the perinatal period with gamma rays

International Nuclear Information System (INIS)

Sasaki, S.; Kasuga, T.

1986-01-01

This study elucidates the life-span radiation effects in mice irradiated at the perinatal period in comparison to mice irradiated at the young adult period. B6C3F 1 female mice were irradiated at 17 days of prenatal age, at 0 days of postnatal age, or as young adults at 15 weeks of age with 190, 380, or 570 rads of 137 Cs gamma rays. Mice irradiated at the late fetal period showed dose-dependent life shortening of somewhat lesser magnitude than that seen after neonatal or young adult irradiation. Mice exposed at the late fetal period were highly susceptible to induction of pituitary tumors for which the latent period was the longest of all induced neoplasms. Incidence of lung tumors in mice irradiated at the late fetal period with 190 and 380 rads was higher than in controls. Malignant lymphomas of the lymphocytic type developed in excess, after a short latent period, in mice irradiated fetally with the highest dose; susceptibility of prenatally exposed mice was lower than that of early postnatally exposed mice. Liver tumors developed more frequently in mice irradiated in utero than in controls; susceptibility to induction of this type of neoplasm was highest at the neonatal period. In general, carcinogenic response of mice exposed at the late fetal period resembled that of neonatally exposed mice but was quite different from that of young adult mice. Mice exposed as young adults have no, or low, susceptibility to induction of pituitary, lung, and liver tumors; and a higher susceptibility to induction of myeloid leukemias and Harderian gland tumors. 19 refs., 4 figs., 3 tabs

Selective elimination of intracortically projecting neurons of the rat neocortex by prenatal x-irradiation

International Nuclear Information System (INIS)

Jensen, K.F.

1981-01-01

The development of new racing methods has suggested that there are species differences in the extent of the contribution of the different layers of the neocortex to the callosal projection. The present investigation has utilized prenatal x-irradiation to selectively eliminate the late forming neurons of the supragranular layers of the rat neocortex. The reduction in the neuronal population of the supragranular layers closely parallels the reduction in the corpus callosum. These results indicate that the primary source of neurons of the callosal projection, are the late forming neurons of the supragranular layers. Thus, the current results suggest that low dose prenatal x-irradiation may be used to evaluate important developmental events in the formation of neocortical circuitry

Irradiation proctitis

International Nuclear Information System (INIS)

Minami, Akira

1977-01-01

Literatures on late rectal injuries are discussed, referring to two patients with uterine cervical cancer in whom irradiation proctitis occurred after telecobalt irradiation following uterine extirpation. To one patients, a total of 5000 rads was irradiated, dividing into 250 rads at one time, and after 3 months, irradiation with a total of 2000 rads, dividing into 200 rads at one time, was further given. In another one patient, two parallel opposing portal irradiation with a total of 6000 rads was given. About a year after the irradiation, rectal injuries and cystitis, accompanying with hemorrhage, were found in both of the patients. Rectal amputation and proctotoreusis were performed. Cystitis was treated by cystic irradiation in the urological department. Pathohistological studies of the rectal specimen revealed atrophic mucosa, and dilatation of the blood vessels and edema in the colonic submucosa. Incidence of this disease, term when the disease occurs, irradiation dose, type of the disease, treatment and prevention are described on the basis of the literatures. (Kanao, N.)

Irradiation proctitis

Energy Technology Data Exchange (ETDEWEB)

Minami, A [Osaka Kita Tsishin Hospital (Japan)

1977-06-01

Literatures on late rectal injuries are discussed, referring to two patients with uterine cervical cancer in whom irradiation proctitis occurred after telecobalt irradiation following uterine extirpation. To one patients, a total of 5000 rads was irradiated, dividing into 250 rads at one time, and after 3 months, irradiation with a total of 2000 rads, dividing into 200 rads at one time, was further given. In another one patient, two parallel opposing portal irradiation with a total of 6000 rads was given. About a year after the irradiation, rectal injuries and cystitis, accompanying with hemorrhage, were found in both of the patients. Rectal amputation and proctotoreusis were performed. Cystitis was treated by cystic irradiation in the urological department. Pathohistological studies of the rectal specimen revealed atrophic mucosa, and dilatation of the blood vessels and edema in the colonic submucosa. Incidence of this disease, term when the disease occurs, irradiation dose, type of the disease, treatment and prevention are described on the basis of the literatures.

Quantitative histologic study on confusion of the cerebellar cortex architecture in perinatally irradiated mice

International Nuclear Information System (INIS)

Sasaki, S.

1986-01-01

This study was designed to know dose-response relationship and age-dependence for two types of confusion of the cerebellar cortex architecture. The first is inhibition of the laminar-pattern development, and the second is persistent remaining of granule cells in the molecular and Purkinje layer which implies disturbance of cell migration. Male B6C3F 1 mice were used. Animals were irradiated at day 0 to 6 of the postnatal age or day 17 of the prenatal age with doses ranging from 50 to 700 rad of γ-rays, and killed at 60 days of age. Confusion of architecture was analysed using microscopic photographs. Development of the laminar-pattern was inhibited by irradiation with 100 rad or higher doses at day 0 to 3. There was a distinct regional difference in inhibition of the laminar-pattern development. Remaining of granule cells was detected after irradiation with 50 or higher doses at day 0 or 2. Irradiation at day 1 to 4 was most effective to disturb cell migration, though ectopic granule cells were detected in all irradiated groups. (orig.)

Long-term effects of prenatal x-ray of human females: reproductive experience

International Nuclear Information System (INIS)

Meyer, M.B.; Tonascia, J.

1981-01-01

A cohort of singleton black human females exposed to diagnostic x-ray in utero and controls matched by parity, hospital of birth and birthdate have been followed to ages 25 to 30 years in Baltimore, Maryland. The search for possible effects of prenatal irradiation has focused on health, growth, development, and reproductive experience of exposed and control women. This paper reports findings related to reproductive experience. From an original data set of 1458 matched exposed-control pairs of women, questionnaire responses were received from 1109 exposed and 1124 control women including 852 each from pairs in which both the exposed and control woman responded. After careful search for alternative explanations of the findings, the authors concluded that females exposed in utero to low doses of x-ray (probably 1 to 5 rads) had significant increases in their rates of early onset of menses, births at age 15 years or less, numbers of living children, stillbirths, and sterilizing operations by their mid-twenties. These findings are compatible with animal studies in which prenatal irradiation kills many oocytes, but accelerates the development of remaining cells to stages more closely correlated with fertility. Although these animals subsequently became sterile, this cannot be tested in the current study because significantly more of the irradiated women have had surgical sterilizations

Roles for the yeast RAD18 and RAD52 DNA repair genes in UV mutagenesis.

Science.gov (United States)

Armstrong, J D; Chadee, D N; Kunz, B A

1994-11-01

Experimental evidence indicates that although the Saccharomyces cerevisiae RAD18 and RAD52 genes are not required for nucleotide excision repair, they function in the processing of UV-induced DNA damage in yeast. Conflicting statements regarding the UV mutability of strains deleted for RAD18 prompted us to re-examine the influence of RAD18, and RAD52, on UV mutagenesis. To do so, we characterized mutations induced by UV in SUP4-o, a yeast suppressor tRNA gene. SUP4-o was maintained on a plasmid in isogenic strains that either carried one of two different rad18 deletions (rad18 delta) or had RAD52 disrupted. Both rad18 deletions decreased the frequency of UV-induced SUP4-o mutations to levels close to those for spontaneous mutagenesis in the rad18 delta backgrounds, and prevented a net increase in mutant yield. A detailed analysis of mutations isolated after UV irradiation of one of the rad18 delta strains uncovered little evidence of the specificity features typical for UV mutagenesis in the isogenic repair-proficient (RAD) parent (e.g., predominance of G.C-->A.T transitions). Evidently, UV induction of SUP4-o mutations is highly dependent on the RAD18 gene. Compared to the RAD strain, disruption of RAD52 reduced the frequency and yield of UV mutagenesis by about two-thirds. Closer inspection revealed that 80% of this reduction was due to a decrease in the frequency of G.C-->A.T transitions. In addition, there were differences in the distributions and site specificities of single base-pair substitutions. Thus, RAD52 also participates in UV mutagenesis of a plasmid-borne gene in yeast, but to a lesser extent than RAD18.

Studies concerning the effects of low level prenatal X-irradiation on postnatal growth and adult behaviour in the Wistar rat

International Nuclear Information System (INIS)

Jensh, R.P.; Brent, R.L.; Vogel, W.H.

1986-01-01

Fifty-nine pregnant Wistar strain rats were sham irradiated or given a 0.1 or 0.2 Gy exposure of X-radiation on the 9th or 17th day of gestation. Twenty-seven were killed at term for teratologic analysis. The remaining mothers raised their young. At 60 days of age the 252 offspring were randomly assigned three of six tests: open field, swimming, hanging, activity wheel, water T-maze, or conditioned avoidance response. Male offspring exposed at the 0.2 Gy level exhibited retarded growth only during the first few weeks of postnatal life. Female offspring exposed on the 17th day to 0.2 Gy X-radiation were growth retarded throughout the test period. Postnatal growth rates were not significantly different between the irradiated and control groups. There were no significant alterations in adult behaviour due to prenatal X-irradiation. There were sex differences in activity wheel and forelimb hanging performance, unrelated to radiation exposure. These results indicate that prenatal low level X-irradiation on the 9th or 17th day of gestation dose not result in significant alterations in rat adult behavioural performance but prenatal growth retardation persists postnatally. Growth may be a more sensitive indicator of the effects of prenatal exposure than postnatal behaviour. (author)

Characterization of new radiation-sensitive mutant, Escherichia coli K-12 radC102

International Nuclear Information System (INIS)

Felzenszwalb, I.; Sargentini, N.J.; Smith, K.C.

1984-01-01

A new radiation-sensitive mutant, radC, has been isolated. The radC gene is located at 81.0 min on the Escherichia coli K-12 linkage map. The radC mutation sensitized cells to uv radiation, but unlike most DNA repair mutations, sensitization to X rays was observed only for rich medium-grown cells. For cells grown in rich medium, the radC mutant was normal for γ radiation mutagenesis, but showed less uv-radiation mutagenesis than the wild-type strain; it showed normal amount of X- and uv-radiation-induced DNA degradation, and it wasapprox. =60% deficient in recombination ability. The radC strain was normal for host cell reactivation of γ and uv-irradiated bacteriophage the radC mutation did not sensitize a recA strain, but did sensitize a radA and a polA strain to X and uv radiation and a uvrA strain to uv radiation. Therefore, it is suggested that the radC gene product plays a role in the growth medium-dependent, recA gene-dependent repair of DNA single-strand breaks after X irradiation, and in postreplication repair after uv irradiation

γ radiation dosimetry in Mega rad range using sugar solution

International Nuclear Information System (INIS)

Venkataramani, R.; Mehta, S.K.; Soman, S.D.

1976-01-01

The formation of malonaldehyde under γ irradiation of solid sucrose and aqueous sucrose, fructose and arabinose solutions has been studied in the Mega rad range. Malonaldehyde (MA) concentration was estimated spectrophotometrically after complexing with 2-thio-barbituric acid. The effect of free radical scavengers (KI and N 2 O) on the yield of MA was investigated. Of the systems studied a 5% aqueous sucrose solution gave a proportional response of MA formation with dose in 0.2 to 5 Mega rad range. A 5% aqueous solution of sucrose prepared from sucrose irradiated in solid state also gave a smooth response of MA yield with dose from 8 to 30 Mega rad. The aqueous and solid sucrose systems together can be conveniently used for dosimetry in the range of 0.2 30 Mega rad. (author)

gamma. radiation dosimetry in Mega rad range using sugar solution

Energy Technology Data Exchange (ETDEWEB)

Venkataramani, R; Mehta, S K; Soman, S D [Bhabha Atomic Research Centre, Bombay (India). Health Physics Div.

1976-09-01

The formation of malonaldehyde under ..gamma.. irradiation of solid sucrose and aqueous sucrose, fructose and arabinose solutions has been studied in the Mega rad range. Malonaldehyde (MA) concentration was estimated spectrophotometrically after complexing with 2-thio-barbituric acid. The effect of free radical scavengers (KI and N/sub 2/O) on the yield of MA was investigated. Of the systems studied a 5% aqueous sucrose solution gave a proportional response of MA formation with dose in 0.2 to 5 Mega rad range. A 5% aqueous solution of sucrose prepared from sucrose irradiated in solid state also gave a smooth response of MA yield with dose from 8 to 30 Mega rad. The aqueous and solid sucrose systems together can be conveniently used for dosimetry in the range of 0.2 30 Mega rad.

Cerebral impact of prenatal irradiation by 131I: an experimental model of clinical neuroradioembryological effects.

Science.gov (United States)

Talko, V V; Loganovsky, K M; Drozd, I P; Tukalenko, Ye V; Loganovska, T K; Nechayev, S Yu; Masiuk, S V; Prokhorova, Ye M

2017-12-01

Human brain in prenatal period is a most vulnerable to ionizing radiation body structure. Unlike atomic bombings or radiological interventions in healthcare leading at most to external irradiation the intensive internal exposure may occur upon nuclear reactor accidents followed by substantial release and fallout of radioactive 131I. The latter can lead to specific neuroradioembryological effects. To create an experimental model of prenatal cerebral radiation effects of 131I in human and to determine the experimental and clinical neuroradioembryological effects.Study object. The neuroradioembryological effects in Vistar rats exposed to 131I in prenatal period. Nervous system status and mental status in 104 persons exposed to ionizing radiation in utero due to the ChNPP accident and the same in 78 not exposed subjects. Experimental i.e. behavioral techniques, including the spontaneous locomotive, exploratory activity and learning ability assessment, clinical i.e. neuropsychiatric, neuro and psychometric, neuropsychological, neurophys iological methods, both with dosimetric and statistical methods were applied. Intrauterine irradiation of Wistar rats by 131I was simulated on a model of one time oral 27.5 kBq radionu clide administration in the mid gestation period (0.72±0.14 Gy fetal thyroid dose), which provides extrapolation of neuroradioembryological effects in rats to that in humans exposed to intrauterine radiation as a result of the Chornobyl catastrophe. Abnormalities in behavioral reactions and decreased output of conditioned reflex reactions identified in the 10 month old rats suggest a deterioration of cerebral cognition in exposed animals. Specific cog nitive deficit featuring a disharmonic intellectual development through the relatively decreased verbal intelligence versus relative increase of nonverbal one is remained in prenatally exposed persons. This can indicate to dysfunc tion of cortical limbic system with especial involvement of a dominant

Prenatal irradiation: radioinduced apoptosis in developing central nervous system; Irradiacion prenatal: apoptosis radioinducida en el sistema nervioso central en desarrollo

Energy Technology Data Exchange (ETDEWEB)

Gisone, P; Dubner, D; Michelin, S; Perez, M R [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Barboza, M [Hospital de Clinicas Jose de San Martin, Buenos Aires (Argentina)

1998-07-01

Severe mental retardation (SMR) is the most significant effect of prenatal irradiation. The high radiosensitivity of developing brain is related with the chronology of morpho genetic phenomena regarding neuroblast proliferation, neuronal differentiation and migration, synaptogenesis and dendritic arborization. Programmed cell death (apoptosis) normally occurs during development in central nervous system (CNS). Apoptosis is a direct result of the expression of specific genes with a final common pathway leading to a characteristic DNA fragmentation pattern. A wide variety of situations and toxic agents have been reported to result in apoptotic death in developing CNS. The aim of this work was the characterization and quantification of apoptosis using an in vitro model of prenatal irradiation. Primary cell cultures from rat brain cortex of 17 days g.a. were irradiated with a gamma source, with doses between 0.2 Gy to 2 Gy. Apoptosis was evaluated 4 hours and 20 hours after irradiation by hematoxylin/eosin, fluorescent microscopy, flow cytometry and DNA electrophoresis. It was also evaluated the neuro protective effect of L-NAME, SOD and glutathion. A dose-dependent increase in apoptotic cell fraction was observed. A protector effect related with the presence of glutathion was observed. (author) [Spanish] Las exposiciones prenatales son motivo frecuente de consulta en el ambito de la radioproteccion. El sistema nervioso es particularmente vulnerable a la accion de la radiacion durante la vida prenatal, con un momento de maxima radiosensibilidad entre las semanas 8 y 15 de edad gestacional (e.g.), durante la cual la frecuencia de retraso mental severo es del orden del 40% por Sievert. La apoptosis, forma activa de muerte celular programada, constituye un proceso fisiologico esencial durante el desarrollo. Las alteraciones de su regulacion podrian jugar un rol en diversas patologias tales como cancer, inmunodeficiencias y enfermedades neurodegenerativas. Se estudio la

Effects of prenatal irradiation with accelerated heavy-ion beams on postnatal development in rats: III. Testicular development and breeding activity

Science.gov (United States)

Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Watanabe, K.; Fujita, K.; Moreno, S. G.; Coffigny, H.; Hayata, I.

With a significant increase in human activities dealing with space missions, potential teratogenic effects on the mammalian reproductive system from prenatal exposure to space radiation have become a hot topic that needs to be addressed. However, even for the ground experiments, such effects from exposure to high LET ionizing radiation are not as well studied as those for low LET ionizing radiations such as X-rays. Using the Heavy-Ion Medical Accelerator in Chiba (HIMAC) and Wistar rats, effects on gonads in prenatal male fetuses, on postnatal testicular development and on breeding activity of male offspring were studied following exposure of the pregnant animals to either accelerated carbon-ion beams with a LET value of about 13 keV/μm or neon-ion beams with a LET value of about 30 keV/μm at a dose range from 0.1 to 2.0 Gy on gestation day 15. The effects of X-rays at 200 kVp estimated for the same biological end points were studied for comparison. A significantly dose-dependent increase of apoptosis in gonocytes appeared 6 h after irradiations with a dose of 0.5 Gy or more. Measured delayed testis descent and malformed testicular seminiferous tubules were observed to be significantly different from the control animals at a dose of 0.5 Gy. These effects are observed to be dose- and LET-dependent. Markedly reduced testicular weight and testicular weight to body weight ratio were scored at postnatal day 30 even in the offspring that were prenatally irradiated with neon-ions at a dose of 0.1 Gy. A dose of 0.5 Gy from neon-ion beams induced a marked decrease in breeding activity in the prenatally irradiated male rats, while for the carbon-ion beams or X-rays, the significantly reduced breeding activity was observed only when the prenatal dose was at 1.0 Gy or more. These findings indicated that prenatal irradiations with heavy-ion beams on gestation day 15 generally induced markedly detrimental effects on prenatal gonads, postnatal testicular development and male

Effects of continuous low-dose prenatal irradiation on neuronal migration in mouse cerebral cortex

International Nuclear Information System (INIS)

Hyodo-Taguchi, Yasuko; Ishikawa, Yuji; Hirobe, Tomohisa; Fushiki, Shinji; Kinoshita, Chikako.

1997-01-01

We investigated the effects of continuous exposure to γ-rays during corticogenesis on the migration of neuronal cells in developing cerebral cortex. Pregnant mice were injected with 0.5 mg of bromodeoxyuridine (BrdU) on day 14 of gestation to label cells in the S phase. The mice were then exposed to 137 Cs γ-rays (dose rates of 0.1, 0.3, and 0.94 Gy/day) continuously for 3 days. Brains from 17-day-old embryos and from offspring at 3 and 8 weeks after birth were processed immunohistochemically to track the movements of BrdU-labeled cells. Comparative analyses of the distribution pattern of BrdU-labeled cells in the cerebral cortex revealed that the migration of neurons was delayed during the embryonic period in mice irradiated at 0.94 Gy/day, in 3-week-old mice, there was a significant difference in the distribution pattern of BrdU-labeled cells in the cerebral cortex between the mice irradiated prenatally and control, and in 8-week-old mice, there were no differences in the distribution pattern of BrdU-labeled cells between control and animals irradiated with 0.1 and 0.3 Gy/day. In contrast, in the animals irradiated with 0.94 Gy/day, the significant difference in the distribution pattern of the labeled cells relative to control was maintained. These results suggest that the migration of neuronal cells in mouse cerebral cortex is disturbed by continuous prenatal irradiation at low-dose and some modificational process occurred during the postnatal period. (author)

Prenatal Co 60-irradiation effects on visual acuity, maturation of the fovea in the retina, and the striate cortex of squirrel monkey offspring

International Nuclear Information System (INIS)

Ordy, J.M.; Brizzee, K.R.; Young, R.

1982-01-01

In the present study, foveal striate cortex depth increased significantly from 1400 μm to 1650 μm by 90 days, whereas prenatal 100 rad exposure resulted in a significant reduction of foveal striate cortex thickness at 90 days of age. From birth to 90 days, cell packing density decreased, whereas overall neuropil density increased in both control and 100 rad exposed offspring. Regarding the effects of prenatal radiation on Meynert cells, there was a significant difference in the time course of early postnatal spine frequency reduction on apical dendrites of Meynert cells, particularly in laminae V and IV. It seems possible that the significant differences in the time course of perinatal increases and subsequent decreases of spines and synapses on such pyramidal neurons as Meynert cells in the deep layers of the striate cortex may play an important role in the development of binocular acuity. Future follow-up studies will be essential from 90 days to 1 and 2 years to determine the extent of recovery from, and persistence of visual acuity impairments in relation to structural alterations in the foveal projection of the retino-geniculo-striate system of diurnal primates. (orig./MG)

Three additional genes involved in pyrimidine dimer removal in Saccharomyces cerevisiae: RAD7, RAD14, and MMS19

Energy Technology Data Exchange (ETDEWEB)

Prakash, L; Prakash, S

1979-01-01

The ability to remove ultraviolet (uv)-induced pyrimidine dimers from the nuclear DNA of yeast was examined in two radiation-sensitive (rad) mutants and one methyl methanesulfonate-sensitive (mms) mutant of the yeast Saccharomyces cerevisiae. The susceptibility of DNA from irradiated cells to nicking by an endonuclease activity prepared from crude extracts of Micrococcus luteus was used to measure the presence of dimers in DNA. The rad7, rad14, and mms19 mutants were found to be defective in their ability to remove uv-induced dimers from nuclear DNA. All three mutants belong to the same episatic group as the other mutants involved in excision-repair. All three mutants show enhanced uv-induced mutations. The rad 14 mutant also shows epistatic interactions with genes in the other two uv repair pathways.

Responses of vibrissa-sensitive cortical neurons in normal and prenatally x-irradiated rat

International Nuclear Information System (INIS)

Ito, M.; Kawabata, M.; Shoji, R.

1979-01-01

Rats were irradiated by 200 R of x ray on day 17 of gestation through the body wall of the mother. When they underwent the following electrophysiological tests at the age of 3 to 4 month, the somatosensory cortex showed a lack of layers II, III, IV, and Va. Spike responses to quick whisker deflections were recorded from single cells in the somatosenory cortex of normal and prenatally x-irradiated rats. For the irradiated rats the response latency was prolonged when compared to the normal controls. Cortical laminar analysis of field potentials revealed that there was no difference in the latency of these potentials between the two groups, suggesting that vibrissal sensory signals reach the cortical level normally even in the irradiated rats. The prolonged latency of the irradiated cortical neuronal response could thus be ascribed to an abnormal intracortical delay, which was most likely associated with the failure of development of layer IV stellate cells in these preparations

Behavioral changes in rats prenatally irradiated with low dose of gamma-rays

International Nuclear Information System (INIS)

Kiskova, J.; Smajda, B.; Capicikova, M.; Lievajova, K.

2006-01-01

In this work, the effects of prenatal gamma-irradiation on behavior in adult Sprague-Dawley rats were studied. Four months old female rats were irradiated with a dose of 1 Gy of gamma-rays on day 15 of gestation. The offspring of irradiated mothers (n=26) and that of control, non-irradiated mothers (n=36) of both sexes at the age of 3 month were tested in Morris's water maze and in open field test. All experimental groups showed a tendency to shortening the time needed to reach the platform in each trial in Morris water maze. Statistically significant difference between irradiated and control rats was detected only in males on 3 rd experimental day. The ability to remember the position of the platform was not altered in irradiated animals after a 4 day pause. In open field test, statistically significant differences in comparison with controls were detected in number of squares entered and in crossings of the central square (P ≤ 0.05) in males. These findings suggest, when comparing with results of other authors, that irradiation effects on postnatal behavior in rats are extremely dependent on the time point of irradiation and that a correlation exist between the developmental stage of the individual brain structures at time of irradiation and the late behavioral effects. (authors)

Effects of prenatal ionizing irradiation on neural function and behavior

International Nuclear Information System (INIS)

Brizzee, K.R.; Ordy, J.M.; Pennwalt Corp., Rochester, NY

1986-01-01

Behavioral studies in the past decade on postnatal effects of prenatal ionizing irradiation (125-R) revealed alterations in circadian locomotor activity and modifications of duration, frequency and sequences of certain behavioral acts in irradiated rats. Other studies have shown that the effect of irradiation (150-R) and enriched environment were both significant in initial, repetitive and total error scores while at 200-R enrichment was less effective. Rats irradiated on the 13th, 14th and 15th day of gestation were born with a hopping gait, paired hind and forelimbs moving in unison. Thoracic cord section led to crossed extention hind-limb reflexes in control rats and simultaneus withdrawal of hind limbs in hopping rats, in response to pinprick. In 90 day old squirrel monkeys the percent of correct response in visual orientation, discrimination and reversal learning in 50- and 100-R offspring (Co 60 irradiation at 89-90 days gestation) were significantly lower than those of controls, and differences in reversal learning persisted undiminished at 2 years of age. Time required for body righting, head-up orientation and climbing at 45 0 incline was significantly greater in irradiated (mainly 100-R) than control animals at from 2 to 28 days of age. Visual acuity levels of 50- and 100-R 30 day old infants were significantly lower than in control infants. Stabilimeter activity in the dark was significantly higher in 50- and 100-R 30 day old infants than in controls. In the squirrel monkey studies effects of Co 60 irradiation (100-R) on postnatal development of the brain and behaviour can be identified at statistically significant levels of confidence independent of offspring nursery rearing effects. (orig.)

Prenatal and neonatal radiation injury and lymphohematopoietic development in the dog

International Nuclear Information System (INIS)

Nold, J.B.

1985-01-01

Immunologic and hematopoietic responses were studied in beagle dogs following prenatal or neonatal irradiation to evaluate the effects of ionizing radiation on the developing lymphohematopoietic system. In prenatally-irradiated dogs thymic medullary volumes were significantly reduced at birth, but had returned to control levels by 12 weeks of age. Irradiated dogs exhibited a significant reduction in primary humoral antibody responses and showed a concurrent decrease in T helper lymphocytes in the peripheral blood. In neonatally-irradiated dogs lymphocyte blastogenic responses were sharply decreased at 8 weeks, but returned to control levels by 12 weeks of age. Contact sensitivity to dinitrochlorobenzene was decreased, indicating reduced cell-mediated immune responses. Alterations in peripheral blood lymphocyte subpopulations included decreases in B cells and increases in T cells, possibly due to increased numbers of T suppressor cells. There were significant reductions in body size and body tissue weights in all irradiated dogs, although these were more severe and persistent in the prenatally-irradiated dogs. These data show that prenatally or neonatally-irradiated dogs have significantly postnatal immunologic and hematopoietic defects. The effect on bone marrow function in prenatally-irradiated dogs was more severe and persistent than in neonatally-irradiated animals; however, the neonatally-irradiated dogs exhibited more severe alterations in lymphocyte subpopulations than did the prenatally-irradiated dogs. The observation of altered lymphocyte subpopulations suggests altered immunoregulation and raises some important questions relating to radiation-induced immunodeficiency and increased susceptibility to clinical disease, including neoplasia

The effect of the timing of prenatal exposure to x-irradiation on Purkinje cell numbers in rat cerebellum

International Nuclear Information System (INIS)

Miki, T.; Satriotomo, I.; Matsumoto, Y.; Kuma, H.; Takeuchi, Y.; Gu

2003-01-01

Full text: Prenatal exposure of the developing brain to X-irradiation is known to cause various deleterious consequences. We have examined the effects of prenatal X-irradiation on the development of the cerebellum. Wistar rats were exposed to 1.5 Gy X-irradiation either on the 14, 15 or 16th day of gestation (E14, E15, E16). Sham-irradiated animals were used as controls. At seven postnatal weeks of age, male rats were deeply anesthetized and killed by intracardiac perfusion with 2.5 % glutaraldehyde in 0.1 M phosphate buffer. The unbiased stereological procedure known as the fractionator method was used to estimate the total number of Purkinje cells in the cerebellum. Body and cerebellar weights from E14 and E15, but not E16 irradiated rats showed significant deficits compared to control animals. Rats irradiated on E16 and control rats had about 285,100 - 304,800 Purkinje cells in the cerebellum. There was no significant difference between these values. However, E14 and E15 irradiated animals had about 117,500 and 196,300 Purkinje cells, respectively. These estimates were significantly different from those observed in both control and E16 irradiated rats. Given that the phase of division of Purkinje cell progenitors is mainly between E14-E15 and the phase of differentiation and migration is between E16-E20, it is concluded that the vulnerable period of the Purkinje cells to X-irradiation closely overlaps the phase of division of progenitors

Rad52 forms DMA repair and recombination centers during S phase

DEFF Research Database (Denmark)

Lisby, M.; Rothstein, R.; Mortensen, Uffe Hasbro

2001-01-01

fluorescent protein (GFP) is fully functional in DNA repair and recombination. After induction of DNA double-strand breaks by gamma -irradiation, meiosis, or the HO endonuclease, Rad52-GFP relocalizes from a diffuse nuclear distribution to distinct foci. Interestingly, Rad52 foci are formed almost exclusively...

Effect of x-ray irradiated rat fetus mandible

International Nuclear Information System (INIS)

Han, Chang Gun; You, Dong Soo

1978-01-01

The effect of irradiation of x-ray to developing rat mandible in the gestation stage was focused on the study of mandible development and the side effect of x-ray irradiation. The author studied the effect of x-ray irradiation with the gestated rat and their offsprings. 100 rads, 200 rads, 300 rads and 400 rads of x-ray was irradiated in regular order schematically at the lower left abdomen of gestated rat. 18 1/2 days after conception, their offsprings were sacrificed and examined their developing mandible with histological findings. The results were as followed. 1. In the 100-200 rads irradiated rat offsprings, bony trabeclulation was revealed irregular shape. In combine with this finding, osteoblast and fibroblast were appeared shrunken of their nucleus and location of eccentric position. 2. In the 300-400 rads irradiated rat offsprings, decrease of fibroblast and osteoblast appearance in the periosteum were prominently observed and empty lacunae were frequently appeared in their bone matrix. 3. The advent of osteoclast and resorption of cortical bone were appeared in proportion to increasing of x-ray irradiation.

Protective effect of the LevRad on treat of paracoccidioidomycosis

International Nuclear Information System (INIS)

Martins, Estefania M.N.; Andrade, Antero S.R.; Fernandes, Viviane Cristina; Morais, Elis Araujo; Goes, Alfredo M.; Resende, Maria Aparecida de

2011-01-01

Paracoccidioides brasiliensis is the agent of Paracoccidioidomycosis (PCM), the most prevalent deep mycosis of Latin America. The period of treat depend on the chemotherapeutic and the severity of disease and its administration not ensure the complete destruction of the fungus. The search for new alternatives is necessary. The aim of this study was to evaluate the protective effect of yeast cells of P. brasiliensis attenuated by gamma irradiation (LevRad) on therapeutic vaccination of BALB/c. The therapeutic potential of LevRad with or without fluconazole was assessed for the first time, intraperitoneally, in BALB/c, 60 days after intratracheal infection with a highly virulent non-irradiated P.brasiliensis isolate. The animals were divided in five experimental groups: uninfected (C-), infected (C+), infected treated with fluconazole (Inmed), infected treated with LevRad (InRad) and infected treated with fluconazole + LevRad (InRadMed). The organs (lungs, spleen and liver) were collected to analyze CFU (colony forming units) and histology. The sera were used to evaluate the immunization efficacy, and to assess IgG subtypes (IgG1, IgG2a, IgG2b, IgG3) and total IgG levels. There was significant decrease in the CFU counts of the lungs of InMed, InRadMed and InRad. No were visualized histopathological alterations in the organs of these groups, except in InRad there was granulomatous lesions unifocal, little and discrete. The levels of IgG and its subtypes IgG2a, IgG2b increased, probably due to the increase of cytokines that promote switching to these isotypes. These preliminary results can provide new prospect for immunotherapy of PCM, but it will be necessary new studies to evaluate administration dose and period treatment. (author)

Recovery of damage in rad-hard MOS devices during and after irradiation by electrons, protons, alphas, and gamma rays

Science.gov (United States)

Brucker, G. J.; Van Gunten, O.; Stassinopoulos, E. G.; Shapiro, P.; August, L. S.; Jordan, T. M.

1983-01-01

This paper reports on the recovery properties of rad-hard MOS devices during and after irradiation by electrons, protons, alphas, and gamma rays. The results indicated that complex recovery properties controlled the damage sensitivities of the tested parts. The results also indicated that damage sensitivities depended on dose rate, total dose, supply bias, gate bias, transistor type, radiation source, and particle energy. The complex nature of these dependencies make interpretation of LSI device performance in space (exposure to entire electron and proton spectra) difficult, if not impossible, without respective ground tests and analyses. Complete recovery of n-channel shifts was observed, in some cases within hours after irradiation, with equilibrium values of threshold voltages greater than their pre-irradiation values. This effect depended on total dose, radiation source, and gate bias during exposure. In contrast, the p-channel shifts recovered only 20 percent within 30 days after irradiation.

Interactions of checkpoint-genes RAD9, RAD17, RAD24 and RAD53 determining radioresistance of Yeast Saccharomyces Cerevisiae

International Nuclear Information System (INIS)

Koltovaya, N.A.; Nikulushkina, Yu.V.; Roshchina, M.P.; Devin, A.B.

2007-01-01

The mechanisms of genetic control of progress through the division cell cycle (checkpoint-control) in yeast Saccharomyces cerevisiae have been studied intensively. To investigate the role of checkpoint-genes RAD9, RAD17, RAD24, RAD53 in cell radioresistance we have investigated cell sensitivity of double mutants to γ-ray. Double mutants involving various combinations with rad9Δ show epistatic interactions, i.e. the sensitivity of the double mutants to γ-ray was no greater than that of more sensitive of the two single mutants. This suggests that all these genes govern the same pathway. This group of genes was named RAD9-epistasis group. It is interesting to note that the genes RAD9 and RAD53 have positive effect but RAD17 and RAD24 have negative effect on radiosensitivity of yeast cells. Interactions between mutations may differ depending on the agent γ-ray or UV-light, for example mutations rad9Δ and rad24Δ show additive effect for γ-ray and epistatic effect for UV-light

Identification of cloned genes that complement the rad50-1, rad51-1, rad54-3 and rad55-3 mutations in yeast

International Nuclear Information System (INIS)

Calderon, I.L.; Contopoulou, C.R.; Mortimer, R.K.

1982-01-01

Plasmids that complement the rad50-1, rad51-1, rad54-3 and rad55-3 mutations in yeast, have been isolated. They were obtained by transforming strains, carrying the leu2-112 leu2-3 alleles and the particular rad mutation, with YEp13 plasmids containing near random yeast DNA inserts. Rad + clones were identified among the Leu + transformants. Integration by targeting into the RAD55 locus showed that the rad55-3 complementing plasmid contained the actual RAD55 gene. BamHI fragments from each of the plasmids that complement rad50-1, rad51-1 and rad54-3, all of which lacked Rad + activity, were subcloned into the integrating plasmid YIp5 and the hybrid plasmids were used to transform a Rad + Ura - strain to Ura + . By genetic mapping, the rad51 and rad54 subclones were shown to integrate at their respective loci. However, the rad50 subclones integrated at a site unlinked to the RAD50 locus. This suggests that no homology exists between this BamHI fragment and the RAD50 gene. Integration at the RAD54 locus of the rad54 subclone made the host cell Ura + but Rad - ; excision of the plasmid was shown to be x-ray inducible and to restore the Ura - Rad + phenotype. These results indicate that the BamHI fragment of the RAD54 plasmid is internal to the RAD54 gene. We can conclude also that the RAD54 gene is not essential as cells bearing a disrupted copy of this gene are able to survive. Additionally, a plasmid carrying an amber suppressor has been isolated and characterized

Effect of Rad 51 overexpression on chromosomal stability and radiation sensitivity in tumour cells

International Nuclear Information System (INIS)

Jend, C.; Stuerzbecher, H.W.; Dikomey, E.; Borgmann, K.

2004-01-01

The present study was dedicated to examining the effects of Rad51 overexpression on genomic instability, expressed in terms of chromosomal aberrations in G1 and G2 phases following X-ray irradiation. For this purpose an osteosarcoma cell line (Ui-OS) which shows inducing Rad51 overexpression (UiRad5-2) after stable transfection was compared with an isogenetic line (UiLacZ) which overexpresses beta-galactosidase instead of Rad51 [de

Lysosomal enzyme activation in irradiated mammary tumors

International Nuclear Information System (INIS)

Clarke, C.; Wills, E.D.

1976-01-01

Lysosomal enzyme activity of C3H mouse mammary tumors was measured quantitatively by a histochemical method. Following whole-body doses of 3600 rad or less no changes were observed in the lysosomal enzyme activity for 12 hr after the irradiation, but very large increases in acid phosphatase and β-naphthylamidase activity were, however, observed 24 hr after irradiation. Significant increases in enzyme activity were detected 72 hr after a dose of 300 rad and the increases of enzyme activity were dose dependent over the range 300 to 900 rad. Testosterone (80 mg/kg) injected into mice 2 hr before irradiation (850 rad) caused a significant increase of lysosomal enzyme activity over and above that of the same dose of irradiation alone. If the tumor-bearing mice were given 95 percent oxygen/5 percent carbon dioxide to breathe for 8 min before irradiation the effect of 850 rad on lysosomal acid phosphatase was increased to 160 percent/that of the irradiation given alone. Activitation of lysosomal enzymes in mammary tumors is an important primary or secondary consequence of radiation

Ionizing radiation-induced foci formation of mammalian Rad51 and Rad54 depends on the Rad51 paralogs, but not on Rad52

International Nuclear Information System (INIS)

Veelen, Lieneke R. van; Essers, Jeroen; Rakt, Mandy W.M.M. van de; Odijk, Hanny; Pastink, Albert; Zdzienicka, MaIgorzata Z.; Paulusma, Coen C.; Kanaar, Roland

2005-01-01

Homologous recombination is of major importance for the prevention of genomic instability during chromosome duplication and repair of DNA damage, especially double-strand breaks. Biochemical experiments have revealed that during the process of homologous recombination the RAD52 group proteins, including Rad51, Rad52 and Rad54, are involved in an essential step: formation of a joint molecule between the broken DNA and the intact repair template. Accessory proteins for this reaction include the Rad51 paralogs and BRCA2. The significance of homologous recombination for the cell is underscored by the evolutionary conservation of the Rad51, Rad52 and Rad54 proteins from yeast to humans. Upon treatment of cells with ionizing radiation, the RAD52 group proteins accumulate at the sites of DNA damage into so-called foci. For the yeast Saccharomyces cerevisiae, foci formation of Rad51 and Rad54 is abrogated in the absence of Rad52, while Rad51 foci formation does occur in the absence of the Rad51 paralog Rad55. By contrast, we show here that in mammalian cells, Rad52 is not required for foci formation of Rad51 and Rad54. Furthermore, radiation-induced foci formation of Rad51 and Rad54 is impaired in all Rad51 paralog and BRCA2 mutant cell lines tested, while Rad52 foci formation is not influenced by a mutation in any of these recombination proteins. Despite their evolutionary conservation and biochemical similarities, S. cerevisiae and mammalian Rad52 appear to differentially contribute to the DNA-damage response

The efficacy of hyperbaric oxygen in modifying the response of tissue to irradiation in doses of 200-400 rad per fraction

International Nuclear Information System (INIS)

Suit, D.D.; Orsi, L.

1975-01-01

The efficacy of respiration of O 2 at 30 psi in modifying the response of normal and tumour tissue to irradiation administered at 200 to 400 rad per fraction to anaesthetized mice has been evaluated. End-points have been delay in growth and TCD 50 for an early generation iso-transplant of a C 3 H mouse mammary carcinoma, and the acute reaction of skin of the C 3 H/Sed mouse. Results showed that the ratios of dose (air)/dose (O 2 30 psi) to elicit these end points were in the range 1.2 to 1.4. In earlier work using the same end points but doses per fraction 430 to 2100 rad, the ratios were 1.6 to 1.8. That is, for these tissue responses, respiration of O 2 at 30 psi increases the response of both normal and tumour tissue to all radiation doses tested. It is of greater effectiveness when combined with large doses per fraction, eg. greater than 430 rad. (author)

The effects of x-ray irradiation on the inner ear

International Nuclear Information System (INIS)

Kanagawa, Kiyoto

1983-01-01

Since the beginning of the 20th century, it has been known that the radiation can cause hearing loss, but the details of this process are not as well known as those of radiation effects on other organs. The author studied the effects of single dose of x-ray irradiation on the inner ear of guinea pigs by continuously measurement of cochlear microphonics (CM) and auditory brainstem responses (ABR) with permanent electrodes implanted on the round window and in the skull. With 2,000, 4,000, and 6,000 rad, slight conductive hearing impairment was observed in some guinea pigs. Severe sensorineural hearing loss was acutely induced by irradiation more than 8,000 rad. After 10,000 rad irradiation, both CM and ABR to air and bone conduction stimuli were usually enhanced by 20-50% above the pre-irradiation levels for one or two hours after completion of the irradiation, and they disappeared simultaneously about 6 hours after irradiation. Hearing impairment began earlier with increase in irradiation: about 10 hours at 8,000 rad, about 6 hours at 10,000 rad, and about 3 hours at 12,000 rad. Responses to high frequency sounds generally disappeared slightly earlier than those to low frequencies. The I-III interpeak latency of ABR didn't change after 10,000 rad irradiation. Endocochlear potential (EP) drop to about 30mV was observed about 7 hours after 10,000 rad irradiation. In the scanning electron micrographs, the sensory hairs in the outer and inner hair cells of every turn seemed to be normal 6 hours after 10,000 rad irradiation. In transmission electron microscopy, however, heavy damages were seen at the outer hair cells in the basal coil of the cochlea. (author)

Skin response to X-irradiation in the guinea-pig

Energy Technology Data Exchange (ETDEWEB)

Berry, R J; Mole, R H; Barnes, D W.H. [Medical Research Council, Harwell (UK). Radiobiological Research Unit

1976-12-01

Skin reaction to X-irradiation has been studied in the albino quinea-pig; early response in limited-field irradiations of the flank was comparable to that commonly seen in rodents, swine and man, and was dose-dependent with a dynamic range from mild erythema to moist desquamation. The peak early skin reaction was seen between 14 and 21 days after irradiation, and declined before 30 days except at the highest doses used. Fractionation of the X-ray dose at 24 hours resulted in a 'sparing' of about 340 rad. Permanent partial epilation was detectable at doses in excess of 1400 rad, and complete epilation at 1 year occurred in 50 per cent of irradiated fields at 1740 rad. Twenty-four hour two-dose fractionation resulted in a 'sparing' of about 500 rad for epilation. Palpable dermal 'fibrosis' was detectable at 3 months after irradiation in fields given more than 2070 rad, and at 1 year after irradiation in fields given more than 1800 rad; 50 per cent of fields showed palpable 'fibrosis' at 1 year at 1930 rad. Unlike domestic swine and man, skin fields in the quinea-pig showed no dimensional contraction after X-ray doses which produced gross early skin damage.

Prenatal deaths and external malformations caused by x-irradiation during the preimplantation period of ddy mice

International Nuclear Information System (INIS)

Ro, Hee Jeong; Choi, Ihl Bhong; Gu, Yeun Wha

1998-01-01

To evaluate the effects of x-irradiation on prenatal deaths, i.e., preimplantation deaths. embryonic deaths, and fetal deaths, and on external malformations in precompacted preimplantation ddy mice. Pregnant mice (n=85), obtained by limiting the mating time to from 6 to 9 A.M., were segregated into 11 groups, The first five groups (n=26) were irradiated with X-ray doses of 0.1, 0.5, 0.75, 1.5, and 3 Gy, respectively, at 24 h post conception (p.c.) of the preimplantation period. The second five (n=27) groups were irradiated at the same X-ray doses, respectively, but at 48 h p.c. of the preimplantation period. The last group (n=32) was the control group. The uterine contents were examined on the 18th day of gestation for prenatal deaths and external malformations. 1) A statistically significant increase in preimplantation deaths with increasing dose was observed in the experimental groups irradiated at 24 h p.c. and in the groups irradiated at 48 h p.c., as compared to the control group. The threshold dose was close to 0.05 Gy and 0.075 Gy for the irradiations at 24 h p.c. and 48 h p.c. respectively. 2) A statistically significant increase in embryonic deaths with increasing dose was observed in all irradiation groups, except the group irradiated with a dose of 0,1 Gy at 48 h p.c.. 3) No fetal deaths were found in any experimental group. 4) In the experimental groups irradiated at 24 h p.c., anomalies increased with statistical significance, as compared with the control group: 2 exencephalies, 2 open eyelids,' 3 anophthalmias, 2 cleft palates. 2 gastroschisis, 1 abdominal wall defect. 1 leg defect, and 2 short tail anomalies; the threshold dose for external malformations was close to 0.2 Gy at 24 h p.c.. In the groups irradiated at 48 h p.c., 1 open eyelid and 2 short tail anomalies were observed, but there was no statistical significance in those malformations. The results of this study reveal that x-irradiation of precompacted preimplantation ddy mice causes not

Rad9 contribution to radiosensitivity and the G2 checkpoint in a DT40 cell line

Energy Technology Data Exchange (ETDEWEB)

Kumano, Tomoyasu [Kanazawa Univ. (Japan). Graduate School of Medical Science

2002-12-01

In fission yeast, the rad9 (radiation sensitive) gene was cloned from a mutant that is sensitive to ionizing radiation, ultraviolet and hydroxyurea. This gene has also been shown to be required for a DNA damage checkpoint. Orthologues of the rad9 gene have recently been identified in higher eukaryote cells including human. Here we generated Rad9 knockout (Rad9-/-) cells from the chicken B lymphocyte line DT40 to examine the role of Rad9 in higher eukaryotes. First we isolated a part of the chicken Rad9 gene which was 54% identical with human Rad9 at the amino acid sequence level. Next we isolated genomic clones, determined exons and introns, and constructed targeting vectors designed to disrupt exon 1-3 of the chicken Rad9 gene by replacement with a drug-resistant gene. Successful targeted integration was verified by Southern blot analysis and the disruption of the Rad9 gene was confirmed by reverse transcription polymerase chain reaction (RT-PCR). To analyze the radiosensitivity of these Rad9-/- cells, we monitored the clonogenic survival after various degrees of X-ray irradiation. Rad9-/- cells were more sensitive to X-rays than wild type cells at all dosages. However, these cells were less sensitive than ATM knockout (ATM-/-) cells that are known to be X-ray sensitive and that showed a defective checkpoint control. In contrast, Rad9-/- cells were markedly more sensitive to ultraviolet and hydroxyruea. In addition, we assessed the G2 checkpoint by measurement of the mitotic index that is the fraction of the accumulating number of cells in mitosis at various times after X-ray irradiation. While the number of mitotic wild type cells did not increase until 2 hrs after X-ray irradiation, the number of mitotic Rad9-/- cells showed an increase similar to that of ATM-/- cells. These results suggest that just as in fission yeast, in higher eukaryotes Rad9 also contributes to X-ray, ultraviolet and hydroxyurea sensitivity, and plays an important role in the G2 checkpoint

Rad9 contribution to radiosensitivity and the G2 checkpoint in a DT40 cell line

International Nuclear Information System (INIS)

Kumano, Tomoyasu

2002-01-01

In fission yeast, the rad9 (radiation sensitive) gene was cloned from a mutant that is sensitive to ionizing radiation, ultraviolet and hydroxyurea. This gene has also been shown to be required for a DNA damage checkpoint. Orthologues of the rad9 gene have recently been identified in higher eukaryote cells including human. Here we generated Rad9 knockout (Rad9-/-) cells from the chicken B lymphocyte line DT40 to examine the role of Rad9 in higher eukaryotes. First we isolated a part of the chicken Rad9 gene which was 54% identical with human Rad9 at the amino acid sequence level. Next we isolated genomic clones, determined exons and introns, and constructed targeting vectors designed to disrupt exon 1-3 of the chicken Rad9 gene by replacement with a drug-resistant gene. Successful targeted integration was verified by Southern blot analysis and the disruption of the Rad9 gene was confirmed by reverse transcription polymerase chain reaction (RT-PCR). To analyze the radiosensitivity of these Rad9-/- cells, we monitored the clonogenic survival after various degrees of X-ray irradiation. Rad9-/- cells were more sensitive to X-rays than wild type cells at all dosages. However, these cells were less sensitive than ATM knockout (ATM-/-) cells that are known to be X-ray sensitive and that showed a defective checkpoint control. In contrast, Rad9-/- cells were markedly more sensitive to ultraviolet and hydroxyruea. In addition, we assessed the G2 checkpoint by measurement of the mitotic index that is the fraction of the accumulating number of cells in mitosis at various times after X-ray irradiation. While the number of mitotic wild type cells did not increase until 2 hrs after X-ray irradiation, the number of mitotic Rad9-/- cells showed an increase similar to that of ATM-/- cells. These results suggest that just as in fission yeast, in higher eukaryotes Rad9 also contributes to X-ray, ultraviolet and hydroxyurea sensitivity, and plays an important role in the G2 checkpoint

Effects of x-irradiation on growth of vascular smooth muscle cells

International Nuclear Information System (INIS)

Dzoga, K.F.; Dimitrievich, G.S.; Sutton, H.G.; Griem, M.L.

1984-01-01

Effects of x-irradiation doses ranging from 0-2000 rads on vascular smooth muscle cells were measured. Explant cultures were from the medial layers of aortas from New Zealand rabbits. X-irradiation was delivered to narrow mediastinal port using a 250 kV Maxitron at a rate of 80 rads/min. and a S-C distance of 60 cm. Explantation was done either immediately following radiation or five days later. Two parameters were used to determine post-irradiation growth potential of these cells: number of outgrowing cells per seeded explant and size and number of cells/culture. Results were expressed as fraction of control. Irradiation immediately before explantation reduced number of cells/ explant 10% for 250 rads and over 50% for 500 rads. Doses of 1000 rads and over resulted in reductions of over 70% in number of growing explants and culture size. When five days were allowed to elapse between x-irradiation and explantation the same parameters were not significantly affected for doses of 500 rads or less. Doses of 1000 rads resulted in a reduction in number of cells of 40% and 2000 rads of over 80%. These results suggest the presence of a population of vascular repair cells five days following irradiation treatment. The nature of these cells is discussed

Intestinal metaplasia induced by x-irradiation in rat

International Nuclear Information System (INIS)

Watanabe, Hiromitsu; Terada, Yoritaka; Fujii, Isao; Yamamoto, Yukiko; Takizawa, Shoichi

1978-01-01

Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation. (Ueda, J.)

Intestinal metaplasia induced by x-irradiation in rat

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H; Terada, Y; Fujii, I; Yamamoto, Y; Takizawa, S [Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology

1978-04-01

Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation.

Vegetative and reproductive performances of irradiated strawberry plants

International Nuclear Information System (INIS)

Velchev, V.; Stoyanov, S.

1982-01-01

The effect of radioactive gamma-irradiation (Cs 137 source with 600 rad/min intensity) at 250 to 1500 rad of the vegetative and reproductive performances of the strawberry was studied, under field conditions with the cvs. Gorella, Cambridge Favourite, and Zenga Zengana. It was found that in all cvs. the highest stimulating effect in respect to number of leaves was produced by rates of 1000 and 1500 rad. Irradiation with 750 and 1000 rad had a stimulating effect on the formation of more flower buds and flowers in Gorella and Cambridge Favourite, while similar effect was evident in Zenga Zengana only at 1000 rad. Radioactive irradiation had different effect on the yield of the cultivars studied. A positive after-effect was observed in the second year in Gorella at 1000 rad - 117512 kg/ha; by Zenga Zengana at 750 rad - 337237 kg/ha; and by Cambridge Favourite at 250 rad - 199766 kg/ha, which represented 113,02; 111,25 and 105.00% respectively as compared to the control

Blood coagulation and fibrinolysis of the whole-body irradiated rabbits

International Nuclear Information System (INIS)

Hishikawa-Itoh, Youko; Ayakawa, Yoshio; Miyata, Nobuki

1984-01-01

To study the effects of irradiation on blood coagulation and fibrinolysis, rabbits were irradiated with 60 Co γ-rays (whole-body: 0, 100, 400, 800, 1200 rads). Clotting time, activity of plasmin and plasminogen, and fibrinogen contents of irradiated rabbit plasma were measured at 4 days before, immediately after, and at 1, 3, 7, 10, and 14 days after irradiation. Both clotting times obtained by addition of (kaolin+phospholipid) which expressed effects on the total intrinsic coagulation system, and by addition of (Ca 2+ ) which expressed effects on the total extrinsic coagulation system, were prolonged with small dose irradiation (100 rads) immediately and 3 days after irradiation. However, with high dose irradiation (400-1200 rads), these clotting times were prolonged 1 day after irradiation. The times of manifestation of irradiation effects on clotting time were different in small and high dose irradiation. Plasmin activity was decreased immediately, 1 day after and recovered 3 days after irradiation. Plasminogen activity was markedly increased in 800 and 1200 rads irradiated groups from 3 days after irradiation. Conversion of plasminogen into plasmin was impaired by irradiation. Fibrinogen contents increased rapidly in all irradiated rabbits except for 100 rads from 1 day after irradiation. These results revealed decreased coagulation and fibrinolysis activities in rabbit blood, irradiation injury of both coagulation and fibrinolysis activation systems, and accumulation of the precursors of fibrin and plasmin (i.e., fibrinogen and plasminogen). (author)

Analysis of behavioural changes induced by prenatal irradiation

International Nuclear Information System (INIS)

Bornhausen, M.

1986-01-01

Two experiments were carried out to detect an impairment of central nervous system functions after prenatal exposure to ionizing radiation. Groups of rats (Wistar) were either irradiated in-utero on the 13th day of gestation with doses of 0.15, 0.30, 0.60 or 0,90 Gy or on days 11, 13 or 16 p.c. with a dose of 0.60 Gy (Cs 137, 1.0 Gy/min). When adult all animals were confronted with a series of standardized tests of operant, instrumental behaviour in which they were required to press a lever for food reward. The contingencies of reinforcement and the data collection from 10 simultaneously operating test chambers were controlled by a microcomputer. The behavioural performance of each exposure group (n=10) and its course during the tests were expressed as percentages of reinforced lever presses/session and compared to other biological, especially weight changes. The analysis of the experimental data obtained so far indicate that the observed performance deficits depended more on the exposure date than on the exposure dose. (orig.)

Caffeine inhibits gene conversion by displacing Rad51 from ssDNA

Science.gov (United States)

Tsabar, Michael; Mason, Jennifer M.; Chan, Yuen-Ling; Bishop, Douglas K.; Haber, James E.

2015-01-01

Efficient repair of chromosomal double-strand breaks (DSBs) by homologous recombination relies on the formation of a Rad51 recombinase filament that forms on single-stranded DNA (ssDNA) created at DSB ends. This filament facilitates the search for a homologous donor sequence and promotes strand invasion. Recently caffeine treatment has been shown to prevent gene targeting in mammalian cells by increasing non-productive Rad51 interactions between the DSB and random regions of the genome. Here we show that caffeine treatment prevents gene conversion in yeast, independently of its inhibition of the Mec1ATR/Tel1ATM-dependent DNA damage response or caffeine's inhibition of 5′ to 3′ resection of DSB ends. Caffeine treatment results in a dosage-dependent eviction of Rad51 from ssDNA. Gene conversion is impaired even at low concentrations of caffeine, where there is no discernible dismantling of the Rad51 filament. Loss of the Rad51 filament integrity is independent of Srs2's Rad51 filament dismantling activity or Rad51's ATPase activity and does not depend on non-specific Rad51 binding to undamaged double-stranded DNA. Caffeine treatment had similar effects on irradiated HeLa cells, promoting loss of previously assembled Rad51 foci. We conclude that caffeine treatment can disrupt gene conversion by disrupting Rad51 filaments. PMID:26019181

Rad-hard embedded computers for nuclear robotics

International Nuclear Information System (INIS)

Giraud, A.; Joffre, F.; Marceau, M.; Robiolle, M.; Brunet, J.P.; Mijuin, D.

1994-01-01

Nuclear industries require robots with embedded rad hard electronics and high reliability. The SYROCO research program allowed to perform efficient industrial prototypes, build according to MICADO architecture, and to design CADMOS architecture. MICADO architecture uses the auto healing property that have CMOS circuits when being switched off during irradiation. (D.L.). 8 refs., 5 figs

Early neuro-vegetative responses to head irradiation of the rabbit at mean absorbed doses of 1000 and 150 rads

International Nuclear Information System (INIS)

Dufour, Raymond.

1977-10-01

Head irradiation was studied in order to back up a previous assumption on the kinetics of vegetative responses to whole-body exposure: the earliest response might have a central origin and explain the slight increase of blood pressure, tachycardia, hyperthermia and hyperventilation. Following head exposure at a mean absorbed dose of 1000 rads, blood pressure increased on the 15 th min, reaching 0.8 - 1 cm Hg on the 30th min and during 7 - 8 hours. The increase of heart rate occured as early and was about 40% and lasted for 24 hours. Body temperature increased as early as the end of exposure, was highest within 2 - 2.30 hours and decreased on the 6th hour. Arterial blood showed a respiratory alkalosis on the 1st hour, lasting after the 6th hour and disappeared within 24 hours. At a dose of 150 rads, the changes were lasting but of lower importance and duration. The results show that early changes following whole-body exposure also occur after head exposure and are magnified. The kinetics involved are discussed [fr

Food Irradiation | RadTown USA | US EPA

Science.gov (United States)

2017-08-07

Using radiation to kill bacteria and other pathogens in food is called food irradiation. Irradiating food kills bacteria and molds that can make people sick. Irradiation does not remove toxins that are already in food. The high energy of the radiation breaks chemical bonds to stop bacteria and other pathogens from multiplying. Irradiation does not make food radioactive.

Radiological effect of single massive irradiation on the liver hilum of rabbits

International Nuclear Information System (INIS)

Todoroki, Takeshi; Tsunemoto, Hiroshi; Usui, Sadahito; Iwasaki, Yoji.

1976-01-01

In order to decide the irradiation dosage, the liver hilum of rabbits had a irradiation of single 3,000 to 5,000 rads of electron beam during the operation. In the acute period from 2 days to 4 weeks after the irradiation, histological studies were carried out to examine the effects on the liver, extrahepatic bile duct, proper hepatic artery and portal vein. On the mucous epithelium of the extrahepatic bile duct, the proliferative changes such as swelling of nuclei, dense arrangement of the nuclei in the epithelial cells were observed. Two weeks later, it was restored to the conditions of the control mucous epitherlium. With 5,000 rads irradiation, even on the 4th week, the recovery was insufficient. The epithelial cells showed atrophy, and nuclei tended to be concentrated. Fibrosis around the bile duct mucous epithelium occurred according to the irradiation doses. It was remarkable with 5,000 rads. The liver reacted the most sensitively, and sporadical and circumscribed necrotic lesions appeared in the parenchyma of the liver. Four weeks after the irradiation of 3,000 rads, necrotic lesions were reduced to become scar and were restored. With 5,000 rads, the necrotic change was stronger than that with 3,000 rads. Although 4 weeks later, necrotic lesion was reduced to become scar, fibrosis of the liver mainly consisting of Glisson's capsule. with 3,000 rads, there was no remarkable change in proper hepatic artery and portal vein. Four weeks after the irradiation of 5,000 rads, thickening of intima and proliferation of intimal cells were observed in part of proper hepatic artery, but there were no hemorrhage or arteral obstruction. Therefore, it can be said that single irradiation of 3,000 rads of electron beam is within the dose to which tissues can tolerate. (N. Kanao)

The response of mammalian cells to UV-light reveals Rad54-dependent and independent pathways of homologous recombination

DEFF Research Database (Denmark)

Eppink, Berina; Tafel, Agnieszka A; Hanada, Katsuhiro

2011-01-01

with lesions in replicating DNA. The core HR protein in mammalian cells is the strand exchange protein RAD51, which is aided by numerous proteins, including RAD54. We used RAD54 as a cellular marker for HR to study the response of mammalian embryonic stem (ES) cells to UV irradiation. In contrast to yeast, ES...

ICRP and impairment of mental function following prenatal irradiation

International Nuclear Information System (INIS)

Mole, R.H.

1992-01-01

A brief account is given of mental retardation and intelligence testing in unirradiated human populations, without which it is not possible to judge the 1991 ICRP Recommendations relating to mental impairment. The dose-response used by ICRP (1991) for the reduction of IQ by irradiation in utero has no radiobiological basis because IQ values are derived from intelligence test scores by transforming the scale of measurement. It is also defective because it assumed that IQ is distributed normally whereas this is so only in normal school children, not in a population in general including retarded persons. There seems good evidence for a substantial threshold of dose for both reduction in IQ and increase in severe mental retardation (SMR). The four prenatally irradiated bomb survivors with SMR and intrauterine dose in the dose range 1-49 cGy were not intelligence tested, so the relation between SMR and IQ in that practically important dose range cannot be examined directly, SMR is a deterministic phenomenon, so is not expected to occur unless dose exceeds a threshold. The threshold doses for SMR based on linear dose-responses using ungrouped doses were 46 and 55 cGy DS86 intrauterine dose (Otake et al 1987). The threshold 50 cGy derived here for reduction in IQ is closely similar. Mild mental retardation has not been reported as a diagnosis in bombs survivors exposed in utero. (Author)

Irradiation and pregnancy

Energy Technology Data Exchange (ETDEWEB)

Chouraqui, A; Creuzillet, C; Barrat, J [Hopital Saint-Antoine, 75 - Paris (France)

1985-04-21

Every single person is exposed to natural (7 rads) or artificail (7.25 rads) irradiation throughout life. To which must be added, for many, irradiation from radiological examinations, which may cause malformations, genetic defects or cancer. The management of irradiated pregnant women depends on the dose received and on the age of pregnancy and requires, when the patient is seen, close co-operation between genetician, radiologist and gynaecologist. A radiological examination may be irreplaceable for diagnostic purposes, but the benefits to be expected from it should not lead to problems, particularly human problems, that are extremely difficult to solve. Non-urgent X-ray examinations should be performed outside pregnancy.

Effects of x-ray irradiation on mast cells and mastocalcergy in the connective tissue

Energy Technology Data Exchange (ETDEWEB)

Song, H. Y.; Rhee, S. J.; Son, M. H.; Choi, K. C. [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

1982-09-15

Experiments were performed to observe the influence of x-ray irradiation on mast cells and mastocalcergy in rats. Animals were irradiated single dose of x-ray. X-ray irradiation was applied to the whole body in doses either 100 rads or 150 rads (Cobalt-60 Teletherapy Unit). One day after irradiation the rats were injected lead acetate intravenously, followed by injection of compound 48/80 in the back subcutaneously. Animals were killed by decapitation at intervals, 1 hour, 5 hours, 1 day and 6 day after subcutaneous injection. Specimens of the abdominal and back skin were fixed in alcohol formol solution and stained with the following methods; H-E for observation of pathological changes of tissues, toluidine blue for demonstration of mast cells, von Kossa-azure A for demonstration of carbonate and phosphate, and chloranilic acid for demonstration of calcium. The following conclusions were obtained. Calciphylatic wheals are large size in the control group, medium size in 100 rads irradiation group and small size in 150 rads irradiation group. In x-ray irradiation groups the number of mast cells decreases more in the 150 rads than in the 100 rads irradiation. In the 100 rads x-ray irradiation group, histochemical study of the injection sites showed that calcium impregnated to mast cell granules and connective tissue fibers in 1 days after subcutaneous injection. The morphogenesis of this calcinosis was the same in the rat of 5 hour after subcutaneous injection of the control group. Whereas, 1 day after subcutaneous injection in 150 rads x-ray irradiation group calcium deposited more slightly than other groups.

Effects of irradiation on the vascularity of lung

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, K; Takegawa, Y; Nagase, M; Akiyama, H [Tokushima Univ. (Japan). School of Medicine

1975-06-01

Effects of irradiation on the intravascular volume of the lung were studied with respect to changes in intravascular volume over a period of time after irradiation, the effect of fractionation of the dose and the influence of the irradiation dose rate. After a single irradiation with 1000 rad or 3000 rad, applied locally to the lung, the intravascular volume decreased significantly in 1 to 3 months after irradiation. The changes in the intravascular volumes of lungs could be lessened by fractionation of the dose or by low dose rate irradiation.

Targeting Rad50 sensitizes human nasopharyngeal carcinoma cells to radiotherapy

International Nuclear Information System (INIS)

Chang, Lihong; Huang, Jiancong; Wang, Kai; Li, Jingjia; Yan, Ruicheng; Zhu, Ling; Ye, Jin; Wu, Xifu; Zhuang, Shimin; Li, Daqing; Zhang, Gehua

2016-01-01

The Mre11-Rad50-Nbs1 (MRN) complex is well known for its crucial role in initiating DNA double strand breaks (DSBs) repair pathways to resistant irradiation (IR) injury and thus facilitating radioresistance which severely reduces radiocurability of nasopharyngeal cancer (NPC). Targeting native cellular MRN function would sensitize NPC cells to IR. A recombinant adenovirus containing a mutant Rad50 gene (Ad-RAD50) expressing Rad50 zinc hook domain but lacking the ATPase domain and the Mre11 interaction domain was constructed to disrupt native cellular MRN functions. The effects of Ad-RAD50 on the MRN functions were assessed in NPC cells lines using western blot, co-immunoprecipitation and confocal microscopy analyses. The increased radiosensitivity of transient Ad-RAD50 to IR was examined in NPC cells, including MTT assay, colony formation. The molecular mechanisms of radiosensitization were confirmed by neutral comet assay and western bolts. Nude mice subcutaneous injection, tumor growth curve and TUNEL assay were used to evaluate tumor regression and apoptosis in vivo. Rad50 is remarkably upregulated in NPC cells after IR, implying the critical role of Rad50 in MRN functions. The transient expression of this mutant Rad50 decreased the levels of native cellular Rad50, Mre11 and Nbs1, weakened the interactions among these proteins, abrogated the G2/M arrest induced by DSBs and reduced the DNA repair ability in NPC cells. A combination of IR and mutant RAD50 therapy produced significant tumor cytotoxicity in vitro, with a corresponding increase in DNA damage, prevented proliferation and cell viability. Furthermore, Ad-RAD50 sensitized NPC cells to IR by causing dramatic tumor regression and inducing apoptosis in vivo. Our findings define a novel therapeutic approach to NPC radiosensitization via targeted native cellular Rad50 disruption. The online version of this article (doi:10.1186/s12885-016-2190-8) contains supplementary material, which is available to

RAD9 deficiency enhances radiation induced bystander DNA damage and transcriptomal response

International Nuclear Information System (INIS)

Ghandhi, Shanaz A; Ponnaiya, Brian; Panigrahi, Sunil K; Hopkins, Kevin M; Cui, Qingping; Hei, Tom K; Amundson, Sally A; Lieberman, Howard B

2014-01-01

Radiation induced bystander effects are an important component of the overall response of cells to irradiation and are associated with human health risks. The mechanism responsible includes intra-cellular and inter-cellular signaling by which the bystander response is propagated. However, details of the signaling mechanism are not well defined. We measured the bystander response of Mrad9 +/+ and Mrad9 −/− mouse embryonic stem cells, as well as human H1299 cells with inherent or RNA interference-mediated reduced RAD9 levels after exposure to 1 Gy α particles, by scoring chromosomal aberrations and micronuclei formation, respectively. In addition, we used microarray gene expression analyses to profile the transcriptome of directly irradiated and bystander H1299 cells. We demonstrated that Mrad9 null enhances chromatid aberration frequency induced by radiation in bystander mouse embryonic stem cells. In addition, we found that H1299 cells with reduced RAD9 protein levels showed a higher frequency of radiation induced bystander micronuclei formation, compared with parental cells containing inherent levels of RAD9. The enhanced bystander response in human cells was associated with a unique transcriptomic profile. In unirradiated cells, RAD9 reduction broadly affected stress response pathways at the mRNA level; there was reduction in transcript levels corresponding to genes encoding multiple members of the UVA-MAPK and p38MAPK families, such as STAT1 and PARP1, suggesting that these signaling mechanisms may not function optimally when RAD9 is reduced. Using network analysis, we found that differential activation of the SP1 and NUPR1 transcriptional regulators was predicted in directly irradiated and bystander H1299 cells. Transcription factor prediction analysis also implied that HIF1α (Hypoxia induced factor 1 alpha) activation by protein stabilization in irradiated cells could be a negative predictor of the bystander response, suggesting that local hypoxic stress

Later Life Changes in Hippocampal Neurogenesis and Behavioral Functions After Low-Dose Prenatal Irradiation at Early Organogenesis Stage

International Nuclear Information System (INIS)

Ganapathi, Ramya; Manda, Kailash

2017-01-01

Purpose: To investigate long-term changes in behavioral functions of mice after exposure to low-dose prenatal radiation at an early organogenesis stage. Methods and Materials: Pregnant C57BL/6J mice were irradiated (20 cGy) at postcoitus day 5.5. The male and female offspring were subjected to different behavioral assays for affective, motor, and cognitive functions at 3, 6, and 12 months of age. Behavioral functions were further correlated with the population of CA1 and CA3 pyramidal neurons and immature neurons in hippocampal dentate gyrus. Results: Prenatally exposed mice of different age groups showed a sex-specific pattern of sustained changes in behavioral functions. Male mice showed significant changes in anxiety-like phenotypes, learning, and long-term memory at age 3 months. At 6 months of age such behavioral functions were recovered to a normal level but could not be sustained at age 12 months. Female mice showed an appreciable recovery in almost all behavioral functions at 12 months. Patterns of change in learning and long-term memory were comparable to the population of CA1 and CA3 pyramidal neurons and doublecortin-positive neurons in hippocampus. Conclusion: Our finding suggests that prenatal (early organogenesis stage) irradiation even at a lower dose level (20 cGy) is sufficient to cause potential changes in neurobehavioral function at later stages of life. Male mice showed relatively higher vulnerability to radiation-induced neurobehavioral changes as compared with female.

Later Life Changes in Hippocampal Neurogenesis and Behavioral Functions After Low-Dose Prenatal Irradiation at Early Organogenesis Stage

Energy Technology Data Exchange (ETDEWEB)

Ganapathi, Ramya; Manda, Kailash, E-mail: kailashmanda@gmail.com

2017-05-01

Purpose: To investigate long-term changes in behavioral functions of mice after exposure to low-dose prenatal radiation at an early organogenesis stage. Methods and Materials: Pregnant C57BL/6J mice were irradiated (20 cGy) at postcoitus day 5.5. The male and female offspring were subjected to different behavioral assays for affective, motor, and cognitive functions at 3, 6, and 12 months of age. Behavioral functions were further correlated with the population of CA1 and CA3 pyramidal neurons and immature neurons in hippocampal dentate gyrus. Results: Prenatally exposed mice of different age groups showed a sex-specific pattern of sustained changes in behavioral functions. Male mice showed significant changes in anxiety-like phenotypes, learning, and long-term memory at age 3 months. At 6 months of age such behavioral functions were recovered to a normal level but could not be sustained at age 12 months. Female mice showed an appreciable recovery in almost all behavioral functions at 12 months. Patterns of change in learning and long-term memory were comparable to the population of CA1 and CA3 pyramidal neurons and doublecortin-positive neurons in hippocampus. Conclusion: Our finding suggests that prenatal (early organogenesis stage) irradiation even at a lower dose level (20 cGy) is sufficient to cause potential changes in neurobehavioral function at later stages of life. Male mice showed relatively higher vulnerability to radiation-induced neurobehavioral changes as compared with female.

Improvement of polyethylene by irradiation in artificial joints

International Nuclear Information System (INIS)

Oonishi, H.; Takayama, Y.

1992-01-01

The decrease in socket thickness of several total hip prostheses was measured on X-ray film. The following prostheses were compared: (1) SOM ''28 mm metal head and an ultra-high-molecular-weight-polyethylene (UHMWPE) socket irradiated with 10 8 rad of γ-radiation'', (2) T-28 ''28 mm metal head and a UHMWPE socket not irradiated'', (3) Bioceram ''28 mm alumina head and UHMWPE not irradiated'' and (4) irradiated Bioceram ''28 mm alumina head and UHMWPE socket irradiated with 10 8 rad of γ-radiation''. The average steady state wear rate of SOM, T-28, Bioceram and irradiated Bioceram were 0.076, 0.247, 0.098 and 0.072 mm/year, respectively. The weight bearing portion of the irradiated socket presented a clearly-outlined and irregular pattern of about 0.1 μm thickness having a smooth ripple surface. The scratch and holding phenomenon characteristic of non-irradiated sockets was not observed at all. In our experimental tests using an IS sliding wear test machine, the wear measured as decrease of thickness was smallest at 10 8 rad, although there was an increase in the coefficient of friction. Our experimental and clinical findings suggest that the best total hip prosthesis at present is one with an alumina head and a UHMWPE socket irradiated with 10 8 rad of γ-radiation. (author)

Morphological study on the effects of 60co γ-irradiation on the testis in the chicken

International Nuclear Information System (INIS)

Lee, Dong Myoung

1990-01-01

This study was undertaken to observe the effects of 60 Co γ-irradiation on the cell of spermatogenic epithelium in the testis of the chicken. 16-week-old chicken were provided as an experimental group and compared with control group. The experimental group was divided into a single irradiation (800, 1000, 1200 rads) and into three partial irradiation group (800/3, 1000/3, 1200/3 rads). The morphological changes of epithelial cell of the testis were observed by means of hematoxyline and eosin stain. Microstructure of spermatocyte and sperm was observed by means of semithin section of electron microscopic specimen. The results obstained are summarized as follows. 1. Spermatogonia and sertoli cells were found to be isolated from the basal membrane of seminiferous tubules as dose of 60 Co γ-irradiation was increased. 2. Spermatocytes of pachytene stage were seperated from the cytoplasmic process of sertoil cell in case of 1000 rads of 60 Co γ-irradiation. Spermatids and sperms were dispersed in the lumen of seminiferous tubules by 1000 rads of 60 Co γ-irradiation. 3. Normal arrangement of the cell of spermatogenic epithelium was found in control group and only the partial irradiation group of 800 rads. Vaculation in the seminiferous was pronounced in case of a single irradiation group of 800 rads, but the irradiation group of 1000 rads and 1200 rads were found to be damaged severely in both a single and a partial dose

Changes in teeth and mandibular vasculature following irradiation

International Nuclear Information System (INIS)

Ishida, Motohisa

1979-01-01

The author studied the effects of radiotherapy on teeth and mandibular vascularization in 60 adult dogs. Cobalt irradiation of the lower right mandible was followed by intravascular injection of chloropercha to delineate the three-dimensional morphology of the changes. The histopathology, X-ray and macroscopic characteristics were also studied. The results were: (1) With 600 rad, fine capillaries around the roots of teeth increased. With 900 - 1,500 rad, the course of blood vessels became irregular. With 1,200 rad, there was a marked increase in capillary vessels which extended meanderingly. With 4,500 rad, the number of blood vessels was markedly decreased. Some vessels were irregular and unclear. (2) Vessels in the dental pulp showed mild meandering with 900 rad. They increased markedly with 1,200 rad and showed meandering. With 4,500 rad, the number of blood vessels decreased. (3) The histopathology showed that, with comparatively small amounts of irradiation, marked vascular disturbance accompanied by vascular dilation and edema had occurred. As the amount of irradiation increased, increased fibrosis of interstitial tissue, decreased numbers of blood vessels, and aseptic necrosis occurred, resulting finally in bone absorption and bone necrosis. (4) X-ray examination showed that mild constriction of the pulp cavity occurred with 3,000 rad. This became marked with 4,500 rad and showed absorption. (5) Macroscopically, 900 rad caused mild edema in the cheek skin. With 3,000 rad, the oral cavity showed some ulceration. With 4,500 rad, necrosis of the gingiva occurred. (6) A certain correlation in the changes of blood vessels, X-ray findings, macroscopical, and pathohistological findings was evident. (author)

Changes in teeth and mandibular vasculature following irradiation

Energy Technology Data Exchange (ETDEWEB)

Ishida, M [Okayama Univ. (Japan). School of Medicine

1979-12-01

The author studied the effects of radiotherapy on teeth and mandibular vascularization in 60 adult dogs. Cobalt irradiation of the lower right mandible was followed by intravascular injection of chloropercha to delineate the three-dimensional morphology of the changes. The histopathology, X-ray and macroscopic characteristics were also studied. The results were: (1) With 600 rad, fine capillaries around the roots of teeth increased. With 900 - 1,500 rad, the course of blood vessels became irregular. With 1,200 rad, there was a marked increase in capillary vessels which extended meanderingly. With 4,500 rad, the number of blood vessels was markedly decreased. Some vessels were irregular and unclear. (2) Vessels in the dental pulp showed mild meandering with 900 rad. They increased markedly with 1,200 rad and showed meandering. With 4,500 rad, the number of blood vessels decreased. (3) The histopathology showed that, with comparatively small amounts of irradiation, marked vascular disturbance accompanied by vascular dilation and edema had occurred. As the amount of irradiation increased, increased fibrosis of interstitial tissue, decreased numbers of blood vessels, and aseptic necrosis occurred, resulting finally in bone absorption and bone necrosis. (4) X-ray examination showed that mild constriction of the pulp cavity occurred with 3,000 rad. This became marked with 4,500 rad and showed absorption. (5) Macroscopically, 900 rad caused mild edema in the cheek skin. With 3,000 rad, the oral cavity showed some ulceration. With 4,500 rad, necrosis of the gingiva occurred. (6) A certain correlation in the changes of blood vessels, X-ray findings, macroscopical, and pathohistological findings was evident.

Stromal cell migration precedes hemopoietic repopulation of the bone marrow after irradiation

International Nuclear Information System (INIS)

Werts, E.D.; Gibson, D.P.; Knapp, S.A.; DeGowin, R.L.

1980-01-01

Circulation of hemopoietic stem cells into an irradiated site has been thoroughly documented, but migration of stromal cells to repair radiation damage has not. We determined the radiosensitivity of mouse bone marrow stroma and evaluated stromal and hemopoietic repopulation in x-irradiated marrow. The D 0 for growth of colonies of marrow stromal cells (MSC) was 215 to 230 rad. Total-body irradiation (TB) obliterated marrow stromal and hemopoietic cells within 3 days. In contrast, 1 day after 1000 rad leg irradiation (LI), MSC rose to 80% of normal, but fell to 34% by 3 days and recovered to 72% by 30 days. However, femoral nucleated cells diminished to 20% by 3 days and recovered to 74% of normal by 30 days. Likewise, differentiated marrow cells and hemopoietic stem cells were initially depleted. With 1000 rad LI followed 3 h later by 1000 rad to the body while shielding the leg, MSC and femoral nucleated cells recovered to values intermediate between 1000 rad TB and 1000 rad LI. We concluded that: (1) the D 0 for MSC was 215 to 230 rad, (2) stromal repopulation preceded hemopoietic recovery, and (3) immigration of stromal cells from an unirradiated sanctuary facilitated hemopoietic repopulation of a heavily irradiated site

Stage-specific effects of X-irradiation on Yeast meiosis

International Nuclear Information System (INIS)

Thorne, L.W.; Byers, B.

1993-01-01

Previous work has shown that cdc 13 causes meiotic arrest of Saccharomyces cerevisiae following DNA replication by a RAD9-dependent mechanism. In the present work, the authors have further investigated the implicit effects of chromosomal lesions on progression through meiosis by exposing yeast cells to X-irradiation at various times during sporulation. They find that exposure of RAD9 cells to X-irradiation early in meiosis prevents sporulation, arresting the cells at a stage prior to premeiotic DNA replication. rad9 meiotic cells are much less responsive to X-irradiation damage, completing sporulation after treatment with doses sufficient to cause arrest of RAD9 strains. These findings thereby reveal a RAD9-dependent checkpoint function in meiosis that is distinct from the G 2 arrest previously shown to result from cdc 13 dysfunction. Analysis of the spores that continued to be produced by either RAD9 or rad9 cultures that were X-irradiated in later stages of sporulation revealed most spores to be viable, even after exposure to radiation doses sufficient to kill most vegetative cells. This finding demonstrates that the lesions induced by X-irradiation at later times fail to trigger the checkpoint function revealed by cdc 13 arrest and suggests that the lesions may be subject to repair by serving as intermediates in the recombination process. Strains mutant for chromosomal synapsis and recombination, and therefore defective in meiotic disjunction, were tested for evidence that X-ray-induced lesions might alleviate inviability by promoting recombination. Enhancement of spore viability when spo 11 (but not hop 1) diploids were X-irradiated during meiosis indicates that induced lesions may partially substitute for SPO 11-dependent functions that are required for the initiation of recombination. 74 refs., 3 figs., 6 tabs

Effects of whole-body cobalt 60 gamma irradiation on the young korean native goats

International Nuclear Information System (INIS)

Kim, Jong Gyu; Sung, Jai Ki

1989-01-01

This study was carried out to investigate the effects of whole-body cobolt-60 gamma irradiation on clinical signs, mortality, hematological, blood chemical, chromosomal and pathologic changes in the young Korean native goats. Groups of goats were exposed to 200, 400, 600 and 800 rads of gamma irradiation from a cobalt-60 source. Clinical signs such as diarrhea, anorexia, weakness and depression of the irradiated goats were observed. Mortalities were 66.7 percent in the group irradiated with 200 rads and 100 percent in the groups irradiated with higher doses. Death times were shortened with the increment of irradiation doses. With time after irradiation, the values of erythrocytes, hemoglobin and packed cell volume decreased in the 200 and 400 rads groups and increased in the 600 and 800 rads groups. The number of total leukocytes of the irradiated goats decreased significantly in all irradiated groups. The degrees of decrease were severe as the irradiated doses were increased. Significant decrease of lymphocyte counts were observed from 6 hours in the 800 rads group and 1 day post irradiation(PI) in all other groups. Post irradiation times for significant reduction of neutrophils were 1, 3, 3 and 5 days for 800, 600, 400 and 200 rads groups, respectively. Serum sorbitol dehydrogenase and serum aspartate aminotransferase activities increased remarkably at 6 hours PI in the 800 rads group and 1 day PI in all other groups. Thereafter the activities returned to normal values. Since mitoses of lymphocytes were completely inhibited in blood cultures of all irradiated goats, chromosomal pictures could not be observed. However, mitoses were observed on 28 days PI in 200 rads group and no abberration in the number and structures of lymphocyte chromosomes were detected. Histopathologic findings in various organs of the irradiated goats were severe necrosis and depletion of lymphoid cells in the lymph nodes and spleen, hypoplasia of hemopoietic cells in the bone marrow

Identification of Rad23-4 gene required for pollen development in ...

African Journals Online (AJOL)

雨林木风

2012-05-31

May 31, 2012 ... in ultraviolet (UV)-B–treated rad23-4 mutants. Compared with the wild type ... discovered in yeast (Guzder et al., 1998). Recent studies showed that ... UV-B irradiation can induce accumulations of anthocyanin in the plants.

Gamma irradiation up to 109 rads of all silica fibers, comparison with polymer clad silica fibers and solid sample between 0.4 and 2.5 micrometers

International Nuclear Information System (INIS)

Boisde, G.; Bonnejean, C.; Perez, J.J.; Neumann, V.; Wurier, B.; Boucher, D.

1983-05-01

The effect of γ radiation (Co 60 ) on optical fibers is studied for investigations to remote measurement in irradiating environments. The spectral characteristics of PCS and AS silica fibers, PCS ''Wet'' and AS ''wet'' and ''superwet'' are compared. An automatic computerized system for measurement ''in situ'' is used between 0,4 AND 1,1 micron. Radiation-induced effects are examined at 840nm on PCS, AS with silicone, AS with epoxy (200 and 400/600μm) up to 5.10 8 rads. Samples of ''dry'', ''wet'', ''superwet'' and ''doped fluor'' silica are studied up to 1,3.10 9 rads between 0,3 and 2,5 μm. The photobleaching, the radiation hardening and the breakeage of PCS and AS-silicone after 10 7 rads are recognized. The spectral characteristics of a band at 610-630nm, a spectral deformation at 945nm for ''wet'' fibers and a peak of the radiation-induced attenuation are observed. The kinetic of the 630nm defect in silica fibers and silica samples is also investigated [fr

Effect of low dose x-irradiation on alloantigen sensitized and unsensitized lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Dohi, Kiyohiko; Yahata, Hiroshi; Fukuda, Yasuhiko; Asahara, Toshimasa; Ono, Eiji; Ezaki, Haruo

1984-12-01

The effect of local graft irradiation on immune response in allograft in which acute rejection occurs was studied using an in vitro model. Unidirectional mixed lymphocyte culture (MLC) was used as the in vitro model of acute rejection. 150 and 300 rad x-irradiation suppressed mixed lymphocyte reaction (MLR) but did not cell-mediated-lympholysis (CML) of unsensitized lymphocytes. X-irradiated alloantigen sensitized cells (ASC) generated in 6-day MLC suppressed MLR and CML of unsensitized lymphocytes. Suppressive effects of x-irradiated ASC were of the same degree by x-irradiation doses of 150-500 rad. Suppressive effect of x-irradiation was maintained for only a short period after x-irradiation. Potential function of suppressor precursor cells among unsensitized lymphocytes was abolished by x-irradiation of 300 rad. (author).

The process of adaptation and evolution in irradiated synthetic populations of Arabidopsis thaliana

International Nuclear Information System (INIS)

Dislers, V.J.; Rasals, I.D.

1975-01-01

Irradiation of synthetic populations of A. thaliana caused an intense process of directed natural selection. As a result, six to eight generations after irradiation, the arithmetic mean of a number of parameters (plant height, stem length, number of internodes) exceeded the arithmetic average for plants in a non-irradiated population. The process of directed selection proceeded more intensely after the plants were irradiated repeatedly than after a single irradiation. The intensity of directed selection when the plants were irradiated with a 10 4 rad dose of fast neutrons was definitely greater than for a dose of 10 3 rad. An intermediate intensity of selection was observed when the plants were irradiated with a 3x10 4 rad dose of gamma radiation. When the plants were subjected to single and repeated 10 4 rad doses of fast neutron radiation, the arithmetic mean of certain features of the best component of the initial population (Enkheim) was exceeded in M 8 and R 6 . (author)

An experimental study of the effect of irradiation (Co60) on wound healing of the esophagus

International Nuclear Information System (INIS)

Shima, Shingo; Sugiura, Yoshiaki; Yonekawa, Hajime; Ogata, Toshiro; Matsuyama, Shigeo

1982-01-01

The cervical esophagus of 22 adult mongrel dogs was irradiated in a schedule of 300 rad per fraction, 3 times a week, to either a total dose of 3000 or 6000 rad. 2 weeks after completion of irradiation, 1 cm of the esophagus in the irradiation field was resected, and Olsen type 1 layered anastomosis was performed. All of the animals were sacrificed for comparison with a non-irradiated group 2 weeks after surgery. Failure of the sutures occurred in 1 of 18 non-irradiated dogs (5.6%), 1 of 9 dogs given 3000 rad (11.1%), with no significant difference, and 5 of 7 given 6000 rad (71.4%), with a significant difference from the other two groups. Irradiation of 3000 or 6000 rad provoked decrease of the interstitial content of hydroxyproline to 70% or 85%, respectively. Although an increasing tendency was observed 2 weeks after anastomosis, the values of the irradiated groups were lower than those of the non-irradiated group. Histopathologically, a strong reaction, chiefly edema, was noted in the submucosal layer. (Chiba, N.)

Ultrastructural changes of central nervous system irradiated with ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Kimura, Y [Keio Univ., Tokyo (Japan). School of Medicine

1975-12-01

Morphological changes of the central nervous tissues (cerebral and cerebellar cortices) of mice which were irradiated by a massive dose (5,000-80,000 rad) of Linac x-ray were observed with the lapse of time by electron microscopy, and changes in their ultrastructure were investigated. Capillaries and the processes of astrocytes surrounding them, when irradiated with 5,000-40,000 rad, showed swelling of endothelial cells, nuclear atrophy, destruction of basement membrane, and swelling and edematous changes of astrocytic processes. Morphological changes of the nerve cells, granule cells of cerebellum, and astrocytes increased depending on the dose of irradiation, and their injuries appeared in the early stage, showing pyknosis, chromatokinesis, and turbid swelling, transparent swelling of mitochondria, and disappearance of Nissl's bodies as cytoplasmic changes. Destruction of cell membrane was observed in the cerebellar granule cells and astrocytes; particularly in the cerebellar granule cells, pyknosis and prominent degeneration of cytoplasm appeared very early, compared with other cells. Although no definite change nor severance was observed in the marrow sheath of medullated nerve fibers within the dose range of this study, an image of degeneration was observed in the mitochondria in the axon; splitting of marrow sheath and deformity of axon membrane were more prominent in the 40,000 rad-irradiated group than in the other groups. Synaptic vesicles tended to increase and scatter when irradiated with 5,000 rad and 10,000 rad. However, by the irradiation with 40,000 rad, the synaptic vesicles tended to enlarge and decrease on the contrary, disappearing with the lapse of time.

Follow-up study on histogenesis of microcephaly associated with ectopic gray matter induced by prenatal γ-irradiation in the mouse

International Nuclear Information System (INIS)

Sun, Xue-Zhi; Inouye, Monoru; Takagishi, Yoshiko

1996-01-01

Brain malformation with ectopic gray matter was visualized with magnetic resonance imaging in small-sized heads of prenatally exposed atomic bomb survivors. The identical brain malformation was reproduced in mice and its histogenesis was studied in the present experiment. Pregnant mice were exposed to 60 Co γ-irradiation at a single dose of 1.5 Gy on embryonic day 13 (E13), and then injected intraperitoneally with 30 mg/kg BrdU on E15. The extensive dead cells appeared throughout the brain mantle at 6 hours (h) after exposure. On E16 cell aggregations formed rosettes. On E18 a high proportion of BrdU-labeled cells reached the superficial layers of the cortical plate with the remaining cells located in the ectopic neuronal masses. The quantitative study showed that labeled cells in layers II to III were fewer and those in layers IV to VI more numerous in the prenatally irradiated adult mice than in controls. The anti-GFAP immunostaining revealed that the glial fibers in the irradiated mice were preserved, but disorganized. These findings suggested that the majority of migrating neurons were able to arrive at their normal layers, but some neurons remained due to the interrupted migratory pathway and eventually formed ectopic neuronal masses beneath the subcortical white matter. 60 refs., 5 figs., 1 tab

Pathological study about two autopsy cases of bilateral irradiation pneumonitis induced by unilateral irradiation

International Nuclear Information System (INIS)

Yamauchi, Noriko; Tajima, Yo; Iio, Masaaki; Oshima, Takeo; Iino, Koichi.

1978-01-01

The first case is a 73-year-old man with left lung cancer. Seven days after completion of radiotherapy 7,000 rad, a chest roentgenogram showed diffuse bilateral pneumonia. The second case is a 61-year-old woman with right lung cancer and about one month after completion of radiotherapy 2,600 rad, a chest roentgenogram showed bilateral pneumonia. Pathological findings, all lobes of both lungs of these cases showed acute interstitial pneumonitis. The pathogenesis of irradiation pneumonitis is poorly understood. Several investigators thought that the pathogenesis of irradiation pneumonitis was caused by autoimmune mechanism, they carried out sero-pathological studies and demonstrated the bilateral pneumonia caused by unilateral irradiation. (author)

In vitro gamma irradiation Medical Center of leukemic cells in mice, rats, and guinea pigs

International Nuclear Information System (INIS)

Gross, L.; Dreyfuss, Y.; Ehrenreich, T.; Feldman, D.; Limbert, L.M.

1980-01-01

In vitro gamma irradiation of virus-induced (Gross) mouse leukemia cells at doses of 350 to 1600 rads (1 rad = 0.01 gray) had no effect on their ability to induce leukemia, usually within 2 weeks, after transplantation into syngeneic mice. However, when cells irradiated at doses of 2000-20,000 rads were transplanted, they induced leukemia after a latency period exceeding 2.5 months, similar to the results observed in mice inoculated with filtered mouse leukemia extracts. Similar results were also obtained after irradiation of leukemic cells derived from rats in which leukemia had been induced by rat-adapted mouse leukemia virus. Apparently, gamma irradiation at a dose of, or exceeding, 2000 rads, inhibits the ability of mouse and rat leukemic cells to induce leukemia after transplantation into syngeneic hosts; however, it does not inactivate the virus carried by such cells nor prevent it from inducing leukemia. [In previous experiments, doses of more than 4,500,000 rads were needed to inactivate the passage A (Gross) leukemia virus carried in either mouse or rat leukemic cells.] In vitro gamma irradiation of L2C guinea pig leukemic cells at doses of 750 to 2500 rads had no apparent effect on their ability to induce leukemia after transplantation into strain 2 guinea pigs. However, irradiation at doses of 3250 to 20,000 rads inactivated their ability to do so. The morphology of mouse, rat, and guinea pig leukemic cells and the virus particles present in such cells was not affected by irradiation at doses of 20,000 rads

An experimental studies of skin autograft in irradiated bed

International Nuclear Information System (INIS)

Ueda, Minoru

1981-01-01

Effects of irradiation to revascularization and skin grafting were studied. Wistar rats were irradiated with 1000, 2000, and 3000 rad of x-ray. One 2, 4, 6, 8, 12, and 24 weeks after irradiation each group, consisted of 10 rats, was compared with that of 34 untreated rats. A new score system of skin reaction was proposed. The highest moist skin reaction was observed after 2 weeks in 3 irradiated groups. In the 2000 and 3000 rad groups, the acute reaction appeared with 1 week latent period and recovered in 8 weeks followed by marked skin atrophy and epilation, while in the 1000 rad group complete recovery was observed in 3 weeks without late squlae. In order to carry out microangiography, a new device to inject the contrast medium at constant temperature and pressure was used. Marked inflammation was observed in 4 weeks, began to recover in 4 weeks, and hypovascular area appeared in 8 weeks. As for the blood area density, no variation was found for the 1000 rad group. However, in the 2000 and 3000 rad groups, the highest density was observed in 2 weeks and decreased after 8 weeks to that lower than the control. Revascularization after the skin grafting was followed by microangiography. In the control group, primary and secondary revascularization was observed one and 3 days after transplantation. As for the 3000 rad groups both revascularizations were hardly recognized when transplanted 8 weeks after irradiation. The optimum time for skin grafting was found to be acute or subacute period of the vascular damage. (Nakanishi, T.)

Experimental study on the effect of x-irradiation in the rat bone matrix

International Nuclear Information System (INIS)

You, Dong Soo

1979-01-01

The author studied on the side effects of x-ray irradiation to the developing mandible of the gestation and period of grow the stage rats. For experimental observation, 100 rads, 200 rads, and 300 rads of x-ray were irradiated in regular order at the lower abdomen of the 8th day gestated rats. 5 weeks after conception, their offspring were sacrificed and their mandibles were extracted with intact form. All the extracted mandible were examined for their developing modes histological findings. The results were as followed; 1) In 10 -200 rads irradiated rats offsprings, their mandibles were not revealed any morphological changes except of the irregular pattern of trabeculatum. In accompany with this findings, most of all the fibroblasts and osteoclasts had their nucleus with shrunken and eccentric position. 2) In according to the increasing x-ray irradiation, marked advent of osteoclast and cortical bone remuamsorption were observed. 3) In 300 rads irradiated rats offsprings, there irregular pattern of trabeculae and widening of bone morrow cavity in their alveolar proper.

Effect of x-ray irradiation on the dentin matrix formation

Energy Technology Data Exchange (ETDEWEB)

You, Dong Soo [Dept. of Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of); Chang, Won Sik [Dept. of Prosthodontics, College of Dentistry, Seoul National University, Seoul (Korea, Republic of); Whang, Sung Myung [Dept. of Oral Antomy, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1976-11-15

The authors has observed the effect of X-ray irradiation on the dentin matrix formation of the albino rat fetuses. The lower abdomen of the pregnant rats were exposed to X-ray on the 9 1/2th day of gestation, respectively 150, 250 and 350 rads. The fetuses of the right side of the same pregnant rats which were not exposed to X-ray were as controls. The results were as follows: 1) In the 150 rads irradiated fetuses, predentin formation was identical with control groups, but the arrangement of od ontoblasts was distorted, subodontoblastic layer was condensed with pulp cells, and blood capillaries were enlarged. 2) In the 250 rads irradiation, dentin matrix was imperfect or osteodentin was occurred. Short columnar or cuboidal od ontoblasts were presented and pulp cells were dispersed. Blood capillaries were congested. 3) 350 rads irradiated fetuses showed osteodentin matrix and numerous degenerated odontoblasts. Their dental papilla sh owed reticular atrophy and enlarged capillary.

The effect of total-body γ-irradiation on pigeons

International Nuclear Information System (INIS)

Gadhia, P.K.; Shah, V.C.; Desai, R.

1979-01-01

A study of the effects of total-body 60 Coγ radiation (200 to 2000 rad) on the common pigeon (Columba livia) has indicated a LD 50/30 of 950 +- 50 rad. There were no deaths before 6 days and the peak frequency in average deaths occurred 9 days after irradiation. Most of the birds showed small changes in activity or behaviour in the first five days. A histopathological study was made of femoral bone marrow from irradiated (1000 rad) pigeons sacrificed 1 to 18 days post-irradiation. Slight aplasia was observed on the first day after irradiation, moderately marked on the third day and extensive on the fourth and fifth days. At the end of the second week regeneration was observed as the primitive lymphocyte-like cells were differentiating into granulocytes and erythrocytes. (UK)

Synergistic interactions between RAD5, RAD16, and RAD54, three partially homologous yeast DNA repair genes each in a different repair pathway

International Nuclear Information System (INIS)

Glassner, B.J.; Mortimer, R.K.

1994-01-01

Considerable homology has recently been noted between the proteins encoded by the RAD5, RAD16 and RAD54 genes of Saccharomyces cerevisiae. These genes are members of the RAD6, RAD3 and RAD50 epistasis groups, respectively, which correspond to the three major DNA repair pathways in yeast. These proteins also share homology with other eucaryotic proteins, including those encoded by SNF2 and MO1 of yeast, brahma and lodestar of Drosophila and the human ERCC6 gene. The homology shares features with known helicases, suggesting a newly identified helicase subfamily. We have constructed a series of congenic single-, double- and triple-deletion mutants involving RAD5, RAD16 and RAD54 to examine the interactions between these genes. Each deletion mutation alone has only a moderate effect on survival after exposure to UV radiation. Each pairwise-double mutant exhibits marked synergism. The triple-deletion mutant displays further synergism. These results confirm the assignment of the RAD54 gene to the RAD50 epistasis group and suggest that the RAD16 gene plays a larger role in DNA repair after exposure to UV radiation than has been suggested previously. Additionally, the proteins encoded by RAD5, RAD16, and RAD54 may compete for the same substrate after damage induced by UV radiation, possibly at an early step in their respective pathways. 49 refs., 6 figs., 2 tabs

X-irradiation effects on growth and metamorphosis of gastropod larvae (Crepidula fornicata): A model for environmental radiation teratogenesis

International Nuclear Information System (INIS)

Gould, L.; Lord, A.; Pechenik, J.; Kase, K.; Fitzgerald, T.J.; Greenberger, J.S.

1985-01-01

Little information is available on the effects of x-irradiation on multicellular marine organisms. C. fornicata larvae were irradiated at 200 rad/min, 250 kVp x-rays to doses between 50 and 20,000 rad in a single fraction. Shell length, biomass, metamorphosis to the next stage of development, and mortality were measured. The results demonstrated a dose-dependent decrease in 20 day shell length at doses above 2000 rad (control 850 +- 110 μm length, 820 +- 100μm for 50 rad, 750 +- 30 μm for 2000 rad, 710 +- 30 μm for 5000 rad, 620 +- 30 μm for 10,000 rad, 580 +- 15 μm for 20,000 rad). There was a dose dependent decrease in shell length growth between days 1 and 20. Biomass was significantly decreased per 100μm shell length for doses above 10,000 rad. A significant increase in larvae mortality was detected with doses above 2000 rad. Most significantly, the cumulative percent of larval metamorphosis was significantly decreased by doses as low as 500 rad and was detectable as early as 18 days after irradiation. C. fornicata may provide a very sensitive system in which to study teratogenic effects of x-irradiation on multicellular organisms

Effects of Prenatal Irradiation with an Accelerated Heavy-Ion Beam on Postnatal Development in Rats

Science.gov (United States)

Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Fujita, K.; Coffigny, H.; Hayata, I.

Effects on postnatal neurophysiological development in offspring were studied following exposure of pregnant Wistar rats to accelerated neon-ion beams with a LET value of about 30 keV mu m at a dose range from 0 1 Gy to 2 0Gy on the 15th day of gestation The age at which four physiologic markers appeared and five reflexes were acquired was examined prior to weaning Gain in body weight was monitored until the offspring were 3 months old Male offspring were evaluated as young adults using two behavioral tests The effects of X-rays at 200 kVp measured for the same biological end points were studied for comparison Our previous study on carbon-ion beams with a LET value of about 13 keV mu m was also cited to elucidate a possible LET-related effect For most of the endpoints at early age significant alteration was even observed in offspring prenatally received 0 1 Gy of accelerated neon ions while neither X rays nor carbon-ions under the same dose resulted in such a significant alteration compared to that from the sham-irradiated dams All offspring whose mothers received 2 0 Gy died prior to weaning Offspring from dams irradiated with accelerated neon ions generally showed higher incidences of prenatal death and preweaning mortality markedly delayed accomplishment in their physiological markers and reflexes and gain in body weight compared to those exposed to X-rays or carbon ions at doses of 0 1 to 1 5 Gy Significantly reduced ratios of main organ weight to body weight at postnatal ages of 30 60 and 90 days were also observed

Influences of nutrition on the biology and midgut histology of gamma irradiated Musca domestica L. (diptera: muscidae)

International Nuclear Information System (INIS)

Banditsing, C.

1975-01-01

The interaction between gamma irradiation and nutrition in the house fly, M. domestica, was investigated following irradiation of 2-hr-old adult virgin females mated with non-irradiated males. Radiation levels used were: 0 (non-irradiated), 250 rads, 500 rads, 750 rads, and 1,500 rads. Flies were fed diets consisting of varying ratio by weight of casein and sucrose at 1:1, 0.5:1, 1:0.5, and 0.1 respectively, and kept in the insectary at 25 +- 2 0 C and 70 percent R.H. Egg hatchability, adult emergence, body and ovary weights, survival of irradiated females, and histopathology were investigated at 4, 7, 11, and 15 days after irradiation. Survival of irradiated females was also determined at 45 days after irradiation. The results of these studies suggest that carbohydrate is important in house fly survival and repair of radiation damage

Dose-incidence relationships for exencephalia, anophthalmia and prenatal mortality in mouse embryos irradiated with fission neutrons or 250 kV X-rays

Energy Technology Data Exchange (ETDEWEB)

Friedberg, W.; Faulkner, D.N.; Neas, B.R.; Hanneman, G.D.; Darden, E.B. Jr.; Deal, R.B. Jr.; Parker, D.E.

1987-08-01

Groups of pregnant mice were irradiated at selected times between 10.00 hours on gestation day 7 and 16.00 hours on day 8. Each group received 0.39 Gy of neutrons or 1.60 Gy of X-rays, or was sham irradiated. We identified a period of high susceptibility of the embryos to radiation-induced exencephalia, anophthalmia and prenatal mortality early in gestation day 8. Dose-incidence relationships in this period were investigated with 0.19-0.48 Gy of neutrons and with 0.40-2.00 Gy of X-rays.

Dose-incidence relationships for exencephalia, anophthalmia and prenatal mortality in mouse embryos irradiated with fission neutrons or 250 kV X-rays

International Nuclear Information System (INIS)

Friedberg, W.; Faulkner, D.N.; Neas, B.R.; Hanneman, G.D.; Deal, R.B. Jr.; Parker, D.E.

1987-01-01

Groups of pregnant mice were irradiated at selected times between 10.00 hours on gestation day 7 and 16.00 hours on day 8. Each group received 0.39 Gy of neutrons or 1.60 Gy of X-rays, or was sham irradiated. We identified a period of high susceptibility of the embryos to radiation-induced exencephalia, anophthalmia and prenatal mortality early in gestation day 8. Dose-incidence relationships in this period were investigated with 0.19-0.48 Gy of neutrons and with 0.40-2.00 Gy of X-rays. (author)

Response of the testis to a combined irradiation

International Nuclear Information System (INIS)

Kondratenko, V.G.; Ganzenko, L.F.

1976-01-01

Testes of dogs have been studied after a combined γ-irradiation (a continuous irradiation with a dose 0,2 rad/day in the course of one year, and acute exposures to doses of 8 and 42 rads thrice a year). As the time of the exposure and the radiation dose increase, the number of active tubules decreases and that of the desolate, increases. A specifity in the testis response to the combined irradiation, in contrast to merely continuous and fractionated exposures, has been detected

Effect of telecobalt irradiation on the function of implantable pacemaker

International Nuclear Information System (INIS)

Toyoda, Michiaki

1986-01-01

In patients implanted with a pacemaker, radiotherapy may be chosen as the treatment when malignant tumor is complicated. Therefore, on the assumption that the pacemaker apparatus is exposed to X-ray, 21 lithium cells used for CMOS or TTL circuit were collected before expiration date and irradiated with 60 Co. The pacemaker used were 10 apparatuses of unprogrammed model VVI, 9 apparatuses of programmed model VVI and 2 apparatuses programmed model DVI. Irradiation was done up to 1,000 rads in dividing doses or at 1,000 rads as a single dose. Observations were made for effects on intervals, amplitude and wave shape of stimula to pacemaker, power, sensitivity, refractory phase, and program functions. In conclusion, it was found that pacemaker is sure to be affected considerably for various functions, although no functional arrest occurs, under irradiation up to 1,000 rads of 60 Co in dividing dose. When irradiation at 1,000 rads was given as a single dose, dysfunctions of pacemaker developed in some cases indicating that direct irradiation at high doses is contraindicated for pacemakers using much of LSI-CMOS. (author)

Influence of different inhibitors on the activity of the RAD54 dependent step of DNA repair in Saccharomyces cerevisiae

Energy Technology Data Exchange (ETDEWEB)

Siede, W.; Obermaier, S.; Eckhardt, F.

1985-01-01

The recombinagenic pathway of DNA repair in yeast was characterized by the effect of different inhibitors on the temperature-dependent survival after ..gamma..-irradiation in haploid cells of the thermoconditional mutant rad54-3. Blocking protein synthesis with cycloheximide in replicating cells caused partial inhibition of the RAD54 dependent function but some repair activity remained detectable. This indicates that ..gamma..-rays can induce RAD54 activity above some constitutive level of function. Inhibition of DNA replication by hydroxyurea efficiently blocked the RAD54 dependent function in stationary-phase cells but not in logarithmic-phase cells. In logarithmic-phase cells, the authors found a strong inhibitory effect of caffeine on the RAD54 mediated repair process.

RAD51AP2, a novel vertebrate- and meiotic-specific protein, sharesa conserved RAD51-interacting C-terminal domain with RAD51AP1/PIR51

Energy Technology Data Exchange (ETDEWEB)

Kovalenko, Oleg V.; Wiese, Claudia; Schild, David

2006-07-25

Many interacting proteins regulate and/or assist the activities of RAD51, a recombinase which plays a critical role in both DNA repair and meiotic recombination. Yeast two-hybrid screening of a human testis cDNA library revealed a new protein, RAD51AP2 (RAD51 Associated Protein 2), that interacts strongly with RAD51. A full-length cDNA clone predicts a novel vertebrate specific protein of 1159 residues, and the RAD51AP2 transcript was observed only in meiotic tissue (i.e. adult testis and fetal ovary), suggesting a meiotic-specific function for RAD51AP2. In HEK293 cells the interaction of RAD51 with an ectopically-expressed recombinant large fragment of RAD51AP2 requires the C-terminal 57 residues of RAD51AP2. This RAD51-binding region shows 81% homology to the C-terminus of RAD51AP1/PIR51, an otherwise totally unrelated RAD51-binding partner that is ubiquitously expressed. Analyses using truncations and point mutations in both RAD51AP1 and RAD51AP2 demonstrate that these proteins use the same structural motif for RAD51 binding. RAD54 shares some homology with this RAD51-binding motif, but this homologous region plays only an accessory role to the adjacent main RAD51-interacting region, which has been narrowed here to 40 amino acids. A novel protein, RAD51AP2, has been discovered that interacts with RAD51 through a C-terminal motif also present in RAD51AP1.

Comparative study of the generative organs of tomatoes irradiated at various times of the ontogenesis

International Nuclear Information System (INIS)

Maulne-Pityinger, O.

1979-01-01

The effect of the irradiation of tomato seed and plant on pollen germination and yield formation has been studied. The dose values, the phenological phase of irradiation and, the connection between the probable stimulating dose and yield formation were studied. According to the results the pollen germination ability was slightly increased by treatment with 500-1000 rad, whereas on the influence of 10000 rad it significantly decreased. In the case of plant irradiation, one tenth of the dose used for seed irradiation was applied. The germination percent increased significantly by 100 rad. From the viewpoint of irradiation treatment the three leaf age appeared to be the most advantageous phenological stage. (author)

Neutron irradiation of rat embryos in utero

International Nuclear Information System (INIS)

Vogel, H.H. Jr.

1978-01-01

In the rat radiation is most effective in producing congenital anomalies during the organ-forming period (days 9 to 13), which is approximately equivalent to the 14th to 50th days of human pregnancy. We have exposed female Sprague--Dawley rats on the 18th day of pregnancy to single whole-body doses of fission neutrons (20 to 150 rads). After 20 rads there was a small decrease in body weight which lasted from birth to weaning. During this period 9% of the irradiated rats died compared with 4% of the controls. After 50 rads, 65/275 (23.6%) of the rats died between birth and weaning, and the body-weight loss of the survivors was increased. After 100 rads, 62/133 (47%) died at birth or day 1 and 103/133 (77.4%) died before weaning. A large and significant decrease in body weight persisted in the survivors. After 150 rads of fission neutrons, all 95 rats died within 48 hr of birth. From cross-fostering experiments, we believe this is a direct effect of radiation on the embryos and not an indirect action through the mother or her milk. The LD 50 for the period from birth to weaning is approximately 75 rads of fission neutrons. Studies of organ weight were conducted daily for the first week after birth in an attempt to find the cause of radiation mortality. Body weight of the irradiated animals averaged only about one-half that of the controls. The liver, kidney, brain, and testes of the neutron-irradiated rats weighed significantly less than those of the controls. The weights of the spleen, lungs, duodenum, and stomach were decreased but not significantly. The bone marrow appeared depleted in the irradiated long bones, but the spleen maintained active hematopoiesis 1 to 2 months after neutron exposure

Degradation of corn starch under the influence of gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

El Saadany, R M.A.; El Saadany, F M; Foda, Y H

1976-01-01

Irradiation of corn (maize) starch with different doses of gamma irradiation ranging from 1 x 10/sup 5/ rad to 1 x 10/sup 6/ rad resulted in the increase of starch acidity and reducing power. Molecular degradation was observed as a result of marked decrease in starch viscosity and intinsic viscosity as well as swelling capacity. The gelatinization time and temperature of the irradiated starch became shorter than in the control sample. Internal changes in the irradiated starch occured as a result of lowering the number of glucose unit per segment in the irradiated starch molecules. All changes were proportional to the doses of gamma irradiation used.

Degradation of corn starch under the influence of gamma irradiation

International Nuclear Information System (INIS)

El Saadany, R.M.A.; El Saadany, F.M.; Foda, Y.H.

1976-01-01

Irradiation of corn (maize) starch with different doses of gamma irradiation ranging from 1 x 10 5 rad to 1 x 10 6 rad resulted in the increase of starch acidity and reducing power. Molecular degradation was observed as a result of marked decrease in starch viscosity and intinsic viscosity as well as swelling capacity. The gelatinization time and temperature of the irradiated starch became shorter than in the control sample. Internal changes in the irradiated starch occured as a result of lowering the number of glucose unit per segment in the irradiated starch molecules. All changes were proportional to the doses of gamma irradiation used. (orig.) [de

Rad51-Rad52 mediated maintenance of centromeric chromatin in Candida albicans.

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Sreyoshi Mitra

2014-04-01

Full Text Available Specification of the centromere location in most eukaryotes is not solely dependent on the DNA sequence. However, the non-genetic determinants of centromere identity are not clearly defined. While multiple mechanisms, individually or in concert, may specify centromeres epigenetically, most studies in this area are focused on a universal factor, a centromere-specific histone H3 variant CENP-A, often considered as the epigenetic determinant of centromere identity. In spite of variable timing of its loading at centromeres across species, a replication coupled early S phase deposition of CENP-A is found in most yeast centromeres. Centromeres are the earliest replicating chromosomal regions in a pathogenic budding yeast Candida albicans. Using a 2-dimensional agarose gel electrophoresis assay, we identify replication origins (ORI7-LI and ORI7-RI proximal to an early replicating centromere (CEN7 in C. albicans. We show that the replication forks stall at CEN7 in a kinetochore dependent manner and fork stalling is reduced in the absence of the homologous recombination (HR proteins Rad51 and Rad52. Deletion of ORI7-RI causes a significant reduction in the stalled fork signal and an increased loss rate of the altered chromosome 7. The HR proteins, Rad51 and Rad52, have been shown to play a role in fork restart. Confocal microscopy shows declustered kinetochores in rad51 and rad52 mutants, which are evidence of kinetochore disintegrity. CENP-ACaCse4 levels at centromeres, as determined by chromatin immunoprecipitation (ChIP experiments, are reduced in absence of Rad51/Rad52 resulting in disruption of the kinetochore structure. Moreover, western blot analysis reveals that delocalized CENP-A molecules in HR mutants degrade in a similar fashion as in other kinetochore mutants described before. Finally, co-immunoprecipitation assays indicate that Rad51 and Rad52 physically interact with CENP-ACaCse4 in vivo. Thus, the HR proteins Rad51 and Rad52

Immunological investigations of antigens released by normal and irradiated schistosomasa mansoni cercariae in vitro. Part of a coordinated programme on preparation of irradiated vaccines against some human diseases

International Nuclear Information System (INIS)

Catty, D.

1982-07-01

S.mansoni cercariae were γ-irradiated at 1-15 K rads, syringe transformed, and injected into groups of 20 mice (200 dose), with unirradiated controls. Aliquots of 1,500 cercariae irradiated at 1-40 K rads (plus unirradiated controls) were cultured in serum-free medium. It was found that irradiation does not inhibit release of a broad spectrum of antigens in culture over 6 hours until 20 K rads is delivered. Mice used as hosts for the graded cercarial irradiation vaccine were subdivided into groups of 10 and either left unchallenged or challenged at 6 weeks with a normal infection of 200 cercariae. Serum samples were taken from every mouse at regular intervals and antibodies titrated by solid phase radioimmunoassay. Injected parasites, whether irradiated or normal, always gave higher antibody titres to cercarial and egg antigens than the equivalent dose of normal (challenge) parasites infecting by the natural route. Challenge infection depressed anti-cercarial responses in mice exposed to irradiated larvae but boosted the response to normal injected parasites. Antibodies to SEA were in lower titre in all groups but rose from week 7 (1 week post-challenge) in the groups injected with normal and 1 K rad-treated parasites, where adults were previously established in the hosts. At 12 weeks all mice were sacrificed and perfused for adults. Egg yields in liver and intestine were determined. There was no evidence of protective immunity to challenge infection induced by injected unirradiated or 1 K rad-irradiated, transformed, cercariae, even though both sources of parasite gave rise to egg-laying adults. By contrast, the 5, 10 and 15 K rad vaccines gave protection of 36-49%, even though they gave rise to no persistent adults or any deposited eggs. The protective (immunising) properties of irradiation-attenuated vaccines of S.mansoni cercariae can thus be clearly correlated with their capacity to release antigens in the immediate post irradiation period

X-irradiation effects on growth and metamorphosis of gastropod larvae (Crepidula fornicata): a model for environmental radiation teratogenesis

Energy Technology Data Exchange (ETDEWEB)

Greenberger, J S; Pechenik, J; Lord, A; Gould, L; Naparstek, E; Kase, K; FitzGerald, T J

1986-02-01

Little information is available on the effects of x-irradiation on the development of multicellular marine organisms. Larvae of the marine gastropod Crepidula fornicata were irradiated at 200 rad/min, 250 kVp X-rays, to doses between 500 and 20,000 rad in a single fraction. During the weeks following exposure, changes in shell length and biomass, incidence of metamorphosis to the juvenile stage of development, and mortality were measured. The results over a 20-day period demonstrated a dose-dependent decrease in growth rate of larval shells following doses above 2000 rad (control at day 20 = 850 +/- 110 ..mu..m length, 820 +/- 11 ..mu..m for 500 rad, 750 +/- 30 ..mu..m for 2000 rad, 710 +/- 30 ..mu..m for 5000 rad, 620 +/- 30 ..mu..m for 10,000 rad, and 580 +/- 15 ..mu..m for 20,000 rad). Shell length-specific biomass was significantly decreased for doses above 10,000 rad. A significant increase in larval mortality was detected with doses above 2000 rad. The cumulative percent of larval metamorphosis was decreased by exposures to 5000 rad and was detectable as early as 18 days after irradiation; however, metamorphosis of larvae after 5000 rad occurred faster by day 21 while other groups metamorphosis required 34-35 days for completion. Crepidula fornicata may provide a very sensitive and convenient system in which to study teratogenic effects of x-irradiation on multicellular organisms.

Effect of whole-body irradiation on skeletal growth in rhesus monkeys

International Nuclear Information System (INIS)

Sonneveld, P.; van Bekkum, D.W.

1979-01-01

Late effects of single whole-body doses of 400 to 500 and 750 to 900 rads on skeletal growth in 32 rhesus monkeys were studied. Findings indicated growth inhibition strongly related to dose and age at irradiation. Doses of 750 to 900 rads before the age of 40 months resulted in significantly greater growth inhibition (11%) than doses given during or shortly after adolescence (p < 0.005). Doses of less than 750 rads were not significant. In view of the close similarity between monkeys and man, irradiation of children at doses greater than 750 rads may carry a strong risk of subsequent growth retardation

Effects of prenatal irradiation with an accelerated heavy-ion beam on postnatal development in rats: II. Further study on neurophysiologic alterations

Science.gov (United States)

Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Watanabe, K.; Fujita, K.; Moreno, S. G.; Coffigny, H.; Hayata, I.

Organogenesis is a highly radiosensitive period, study of prenatal exposure to high LET heavy ion beams on postnatal development is important for clarifying the radiation risk in space and promoting the evidence-based mechanism research. The effects from heavy ion irradiations are not well studied as those for low LET radiations such as X-rays in this field, even the ground-based investigations remain to be addressed. Using the Heavy Ion Medical Accelerator in Chiba (HIMAC) and Wistar rats, postnatal neurophysiological development in offspring was investigated following exposure of pregnant rats to accelerated neon-ion beams with a LET value of about 30 keV/μm at a dose range from 0.1 to 2.0 Gy on the 15th day of gestation. The age for appearance of four physiologic markers and attainment of five neonatal reflexes, and gain in body weight were monitored. Male offspring were evaluated as young adults using two behavioral tests including open field and hole-board dipping tests. The effects of X-rays at 200 kVp measured for the same biological end points were studied for comparison. For most of the endpoints at early age, significant neurophysiological alteration was observed even in offspring receiving 0.1 Gy of accelerated neon ions but not X-rays. All offspring receiving 2.0 Gy of accelerated neon ions died prior to weaning. Offspring prenatally irradiated with neon ions generally showed higher incidences of prenatal death, increased preweaning mortality, markedly delayed accomplishment in physiological markers and reflexes, significantly lower body weight and reduced ratios of main organ weight to body weight, and altered behavior compared to those exposed to X-rays at doses of 0.1 1.5 Gy. These findings indicate that irradiations with neon ions at 0.1 1.5 Gy on day 15 of gestation caused varied developmental alterations in offspring, and efficient dose leading to the detrimental effects seemed to be lower than that of X-rays.

The effects of x-irradiation in the mosquito Aedes aegypti (L)

International Nuclear Information System (INIS)

Read, N.G.

1980-01-01

Newly emerged mosquitoes (Aedes aegypti (L)) were exposed to doses of 500 to 32,000 rad X-irradiation and the LD 50 and mean survival time determined. Radiation doses between 500 and 8,000 rad had only a slight effect on longevity whereas exposure to 32,000 had an appreciable effect. The midgut structure of newly emerged, X-irradiated female Aedes aegypti imagines was examined at set intervals after irradiation. The cytochemical localization of midgut acid phosphatase, alkaline phosphatase and adenosine triphosphatase, and also quantitative estimates of midgut acid and alkaline phosphatase were carried out on mosquitoes exposed to 32,000 rad. Considerable changes in the structure of the midgut cells were apparent. With 500, 4,000 and 8,000 rad there was evidence of cellular repair and recovery. However, with 32,000 rad cellular damage was most extensive, with considerable loss of cell structure. The ultrastructural changes noted suggest that the primary radiation damage was to the plasma and organelle membranes, which is in agreement with the membrane-damage/enzyme release hypothesis. (author)

Post-irradiation treatment of human lymphocytes with spermidine reduced frequency of chromatid breaks

International Nuclear Information System (INIS)

Bocian, E.; Rosiek, O.; Ziemba-Zoltowska, B.

1978-01-01

Human lymphocyte cultures were X-irradiated with a single dose of 100 or 200 rad 46 h after phytohemagglutinin stimulation. In dose-fractionation experiments, 2h later the second dose was applied. All the cultures were harvested at 54 h after their initiation. In lymphocytes irradiated with a single dose of 200 rad, 2h post-irradiation contact with 10 -5 M exogeneous spermidine resulted in reduction of chromatid breaks by 34 %. Introduction of spermidine into culture medium for fractionation interval between the 2 doses of 100 rad reduced the frequency of chromatid breaks by 42 %. (author)

Studies on gamma-irradiation of high amylose corn starch, 1

International Nuclear Information System (INIS)

Watanabe, Yukio; Ayano, Yuko; Obara, Tetsujiro.

1976-01-01

Amylomaize 7, amylomaize 5, normal corn, waxy corn and potato starches were irradiated with 60 Co-gamma rays at the dose levels from 2x10 4 to 100x10 4 rad to determine the changes in physicochemical properties by irradiation. Irradiated starches were characterized by determination of amylography, specific viscosity, blue value, pH, acidity, carbonyl content, reducing value and limit of β-amylolysis. Irradiated starches showed a decrease in viscosity and blue value, and an increase in reducing value with increasing dose levels. These results were seemed to indicate the degradation of starch molecule. A slight oxidation of starch was suggested by a decrease in pH and an increase in acidity and carbonyl content. Amylomaize 7 and amylomaize 5 starches were less sensitive than the other starches in terms of irradiation effects. The rheological properties determined by amylography and Ostwald viscometer changed at the lowest dose (5x10 4 rad) and the other properties changed above 20x10 4 rad. The limits of β-amylase hydrolysis of normal corn, waxy corn and potato starches increased slightly by irradiation (100x10 4 rad). On the other hand, β-amylolysis limits of amylomaize 7 and amylomaize 5 starches were lower about 5.5% and 2.5% respectively than that of nonirradiated samples. The decrease of β-amylolysis limit enlarged with increasing amylose content. (auth.)

Transformation of Saccharomyces cerevisiae with UV-irradiated single-stranded plasmid.

Science.gov (United States)

Zgaga, Z

1991-08-01

UV-irradiated single-stranded replicative plasmids were used to transform different yeast strains. The low doses of UV used in this study (10-75 J/m2) caused a significant decrease in the transforming efficiency of plasmid DNA in the Rad+ strain, while they had no effect on transformation with double-stranded plasmids of comparable size. Neither the rev3 mutation, nor the rad18 or rad52 mutations influenced the efficiency of transformation with irradiated single-stranded plasmid. However, it was found to be decreased in the double rev3 rad52 mutant. Extracellular irradiation of plasmid that contains both URA3 and LEU2 genes (psLU) gave rise to up to 5% Leu- transformants among selected Ura+ ones in the repair-proficient strain. Induction of Leu- transformants was dose-dependent and only partially depressed in the rev3 mutant. These results suggest that both mutagenic and recombinational repair processes operate on UV-damaged single-stranded DNA in yeast.

Effect of gamma-irradiation on mouse pancreatic islet-allograft survival

International Nuclear Information System (INIS)

Kanai, T.; Porter, J.; Gotoh, M.; Monaco, A.P.; Maki, T.

1989-01-01

Elimination or inactivation of lymphoid tissue in the pancreatic islet preparation achieves prolongation of islet-allograft survival. In this study we examined the effect of gamma-irradiation on mouse islet-allograft survival. In a B6AF1 isograft model, irradiation up to 2400 rad did not induce deterioration of islet function over 200 days, but greater doses caused cessation of graft function between 83 and 186 days. When DBA/2 crude islets were transplanted into B6AF1 recipients, all nonirradiated allografts were acutely rejected. Marked prolongation of allograft survival was achieved by islet irradiation with doses between 800 and 12,000 rad. With higher doses, significant numbers of allografts survived beyond the controls, but many lost function between 78 and 180 days, with none surviving greater than 200 days. Irradiation with 16,000 rad caused acute radiation damage. Because most secondary islet allografts in recipient mice that lost primary islet-graft function between 84 and 195 days survived greater than 100 days, late functional loss was probably due to the radiation injury. Combined use of recipient treatment with cyclosporin A and graft irradiation (2400 rad) achieved prolongation of DBA/2 islets in B6AF1 mice

Mutagenic effect of cyclophosphan on bone marrow cells of irradiated rats

International Nuclear Information System (INIS)

Barkan, R.S.; Yakovleva, T.K.

1979-01-01

The frequency of chromosome aberrations in bone marrow cells of male rats was studied 24 hours after the intraperitoneal injection of cyclophosphane (25 mg/kg weight). Cyclophosphane (CP) was injected to animals that had been earlier (15 days before, 1, 3, 4, 6 and 9 months earlier) exposed to X-ray and γ-irradiation at the dose of 400 rad. It has been shown that the preliminary irradiation of animals results in a higher mutagenic CP effect as against its effect for non irradiated rats. The effect was recorded during four months following the acute single x-irradiation (dose rate of 70 rad/min) and within one month following chronic γ-irradiation (dose rate of 100 rad/day). At later periods, the above effect fully disappeared. Chronic irradiation was less effective with regard to the subsequent mutagenic CP action than the acute irradiation. In most experiments with acute irradiation an increase in mutagenic CP efficiency revealed itself both in an increase in the frequency of cells with chromosome aberrations and in the cell damage rate. The possible mechanisms of the effect of preliminary irradiation on the subsequent mutagenic effect of chemical compounds are discussed

Prenatal death and malformations after irradiation of mouse zygotes with neutrons or X-rays

International Nuclear Information System (INIS)

Pampfer, S.; Streffer, C.

1988-01-01

Female mice (strain: Heiligenberger Stamm) were irradiated with neutrons (7 MeV) or X-rays when embryos were at the early zygote stage; uterine contents were examined on gestation day 19 for prenatal mortality and malformed fetuses. For both radiation qualities, the dose-dependent survival curve fitted well to a simple exponential equation; the neutron relative biological efficiency (RBE) value was 2.3. The major fraction of deaths induced by exposure to neutrons or X-rays occurred before implantation. Aside from dead embryos, malformed fetuses were observed 19 days p.c. (postconception). The number of malformed fetuses increased with a linear-quadratic function of neutron or X-ray dose. Malformations were mainly gastroschisis, although omphaloceles and anencephalies were also observed. The neutron RBE value for the induction of malformations varied from 2.0 to 2.8 in the dose range tested. Except after 75-cGy neutrons, no significant increase in the proportion of stunted or skeletally malformed fetuses was noted. Our results indicated that the reaction of preimplantation embryos to irradiation could be more complex than the simple all-or-none response considered so far

Schizosaccharomyces pombe Rad22A and Rad22B have similar biochemical properties and form multimeric structures

Energy Technology Data Exchange (ETDEWEB)

Vries, Femke A.T. de [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Zonneveld, Jose B.M. [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Groot, Anton J. de [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Koning, Roman I. [Department of Molecular Cell Biology, Leiden University Medical Center, Leiden (Netherlands); Zeeland, Albert A. van [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Pastink, Albert [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands)]. E-mail: A.Pastink@lumc.nl

2007-02-03

The Saccharomyces cerevisiae Rad52 protein has a crucial role in the repair of DNA double-strand breaks by homologous recombination. In vitro, Rad52 displays DNA binding and strand annealing activities and promotes Rad51-mediated strand exchange. Schizosaccharomyces pombe has two Rad52 homologues, Rad22A and Rad22B. Whereas rad22A deficient strains exhibit severe defects in repair and recombination, rad22B mutants have a much less severe phenotype. To better understand the role of Rad22A and Rad22B in double-strand break repair, both proteins were purified to near homogeneity. Using gel retardation and filter binding assays, binding of Rad22A and Rad22B to short single-stranded DNAs was demonstrated. Binding of Rad22A to double-stranded oligonucleotides or linearized plasmid molecules containing blunt ends or short single-stranded overhangs could not be detected. Rad22B also does not bind efficiently to short duplex oligonucleotides but binds readily to DNA fragments containing 3'-overhangs. Rad22A as well as Rad22B efficiently promote annealing of complementary single-stranded DNAs. In the presence of Rad22A annealing of complementary DNAs is almost 90%. Whereas in reactions containing Rad22B the maximum level of annealing is 60%, most likely due to inhibition of the reaction by duplex DNA. Gel-filtration experiments and electron microscopic analyses indicate self-association of Rad22A and Rad22B and the formation of multimeric structures as has been observed for Rad52 in yeast and man.

Study of the biochemical indicators of chronic irradiation in rats.

Science.gov (United States)

Szabo, L D; Benko, A B; Gyenge, L; Predmerszky, T

1976-01-01

Daily urinary excretion of pseudouridine, creatinine and creatine of chronically irradiated Wistar rats was estimated. The irradiation conditions were: 60Co gamma source, dose-rate 10 rad/day, total dose 200, 400 and 600 rad. Control groups were kept under similar conditions. Urine samples were taken three times after the end of the irradiation period. It was found that: (1) pseudouridine excretion seems more suitable for indicating radiation injury than the creatine/creatinine ratio in chronic irradiation in rats; (ii) there are significant changes in dose dependence of pseudouridine excretion in the post-irradiation period; (iii) a new method for pseudouridine estimation gives closely similar data to those of earlier investigations.

Genetic control of mitotic crossing over in yeast. 2. Influence of UV irradiation

International Nuclear Information System (INIS)

Zakharov, I.A.; Marfin, S.V.; Koval'tsova, S.V.; Kasinova, G.V.

1982-01-01

UV-induced crossing-over and general mitotic segregation of the following strains of Saccharomyces cerevisiae yeasts were studied: a wild-type diploid, diploids homozygous with respect to the radiosensitivity of rad 2, rad 15, rad 54, xrs 4, rad 2 rad 54, rad 15 rad 54. Wild-type diploids rad 2 and rad 15 have a high frequency of the induced mitotic crossing-over. Diploids rad 15, rad 54 can not cause UV-induced mitotic crossing-over. Reddish-pink and reddish-pink-white colonies ratio (the first appear if the crossing-over occurs during the first after the irradiation division, the second - during the second division) is 4.8:1 for the wild type, 1.6:1 for rad 2, and 1.1:1 for rad 15. Nonreciprocal mitotic segregation of high frequency was observed for the wild type rad 2, rad 15, xrs 4, and diploids rad 54, rad 2 rad 54, rad 15 rad 54 had a lower frequency. We suppose that after UV-irradiation there exist at least three types of repair in yeast diploid cells: excision repair, prereplication recombinating repair after the excision of dimers, and post-replication recombinating repair. Rad 2 and rad 15 mutations blow the first and second types, rad 54 mutation partially block the second and third parths. It seems that xrs 4 mutation does not block the recombinating capability but somehow changes the process of recombination in such a way that much nonreciprocal products recorded as seqregants are produced [ru

Effects of 60Co gamma-ray local irradiation on rat liver on alkaline phosphatase, lactate dehydrogenase and catalase in the liver and serum

International Nuclear Information System (INIS)

Hishikawa-Itoh, Youko; Ayakawa, Yoshio; Miyata, Nobuki

1980-01-01

Rats were given a single exposure of various doses (0, 5, 50, 500, and 5000 rads) to local irradiation of 60 Co γ-ray on liver. Activities of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and catalase in the serum and liver were measured at various time intervals after irradiation. These results were summarized as follows; 1. ALP activity in the serum had no effect on irradiation up to 500 rads, but in the case of 5000 rads irradiation exhibited a marked loss from 4 days after irradiation. ALP activity in the liver to 5000 rads exposure on 7 days after irradiation increased, on the other hand in the serum decreased, and the patterns of ALP activities in the liver and serum to the irradiation doses were opposite. 2. LDH activity in the serum by exposure to 5, 500 and 5000 rads increased at 4 days after irradiation, but at 7 days significantly decreased. LDH activity in the liver to the irradiation doses on 7 days after irradiation did not markedly change, but in the serum it tended to be low in inverse proportion to the irradiation doses. 3. Catalase activity in the serum to 50 and 500 rads exposure increased at 4 days after irradiation and decreased at 7 days, but to 5000 rads exposure it decreased in the course of time. Catalase activity in the liver and serum on 7 days after irradiation were inversely proportional to irradiation doses. It is difficult that catalase activity makes a index of clinical irradiation effects, because catalase activity decrease under the various conditions, such as cancer, anemia, infection of bacterias and so on. Since activities of ALP and LDH increase in almost disease, decrease of ALP activity and decrease following temporary increase of LDH activity by irradiation may be able to become a clinical indicator on irradiation effects. (author)

Cell-kinetics of the human uterine cervical carcinoma cells during radium irradiation

International Nuclear Information System (INIS)

Iwata, Masaharu; Sasaki, Hiroshi

1983-01-01

HeLa cells grown in a monolayer culture and in nude mice were exposed to graded dose rates (37, 55 or 200 rad/hour) and doses (500-2,000 rad) of radiation and analyzed in terms of their cell cycle distribution using flow-microfluorometry. In the case of the cultured HeLa cells, dose-survival curves were constructed using colony formation as the end-point. The HeLa cells, both in vitro and in vivo, accumulated in G2-M phases after both acute and chronic irradiation. The dose rate of 37 rad/hour proved to be the most effective in producing G2-M accumulation, which is the sensitive phase of the cell cycle. In comparing the G2-M accumulation to the irradiation time, 55 and 37 rad/hour proved to be similarly efficient in producing G2-M accumulation, both in vitro and in vivo. When survival of HeLa cells in vitro was studied, the radiation-induced changes in cell distribution correlated with cell survival and accounted for the change in the dose rate effect above 1,000 rads. In the case of in vivo HeLa cells, the decrease in the number of G0+G1 stage cells was demonstrated during chronic irradiation (37 and 55 rad/hour). The two low dose rates were equally efficient in producing a decrease in the number of G0+G1 cells. These data indicate that chronic irradiation induces redistribution and recruitment more effectively than acute irradiation. (author)

Carcinoma of the pancreas: results of irradiation for unresectable lesions

International Nuclear Information System (INIS)

Komaki, R.; Wilson, J.F.; Cox, J.D.; Kline, R.W.

1980-01-01

From 1973 to 1977, 20 patients who had histologically proven unresectable adenocarcinoma of the pancreas with no distant metastases were irradiated at the Medical College of Wisconsin Affiliated Hospitals. The patients received megavoltage external irradiation to minimum tumor doses ranging between 3000 rad in 4 weeks and 5700 rad in 7 weeks (median 4600 rad in 6 weeks); their actuarial survival was 54% at 12 months and 21% at 24 months. Fourteen patients who received 4500 rad or more in 6 to 7 weeks had a median survival of 13 months. Six patients received less than 4500 rad in 3 to 6 weeks, and their median survival was 7 months. At this writing, three patients are alive and apparently disease free more than 2 years after treatment. Complications were seen in two patients. One died from GI bleeding 2 months after completion of radiation therapy, and the other patient developed pancreatic insufficiency. These results and recent reports in the literature show that aggressive irradiation can result in long-term disease free survival in a small proportion of patients with unresectable pancreatic adenocarcinoma. Further exploitation of this approach alone or combined with chemotherapy is warranted

Effect of irradiation on lysosomal enzyme activation in cultured macrophages

International Nuclear Information System (INIS)

Clarke, C.; Wills, E.D.

1980-01-01

The effect of γrays on lysosomal enzyme activity of normal and immune macrophages of DBA/2 mice cultured in vitro has been studied. A dose of 500 rad did not significantly affect lysosomal enzyme activity 3 hours after irradiation but caused the activity to increase to 1.4 times the control value 22.5 hours after irradiation. 22.5 hours after a dose of 3000 rad the enzyme activity increased to 2.5 times the control. Lysosomal enzyme activity of the macrophages was also markedly increased by immunization of the mice with D lymphoma cells, before culture in vitro, but irradiation of these cells with a dose of 500 rad caused a further increase in lysosomal enzyme activity. The results indicate that immunization and irradiation both cause stimulation of lysosomal enzyme activity in macrophages but that the mechanisms of activation are unlikely to be identical. (author)

p53 is involved in clearance of ionizing radiation-induced RAD51 foci in a human colon cancer cell line

International Nuclear Information System (INIS)

Orre, Lukas M.; Stenerloew, Bo; Dhar, Sumeer; Larsson, Rolf; Lewensohn, Rolf; Lehtioe, Janne

2006-01-01

We have investigated p53-related differences in cellular response to DNA damaging agents, focusing on p53s effects on RAD51 protein level and sub-cellular localization post exposure to ionizing radiation. In a human colon cancer cell line, HCT116 and its isogenic p53-/- subcell line we show here p53-independent RAD51 foci formation but interestingly the resolution of RAD51 foci showed clear p53 dependence. In p53 wt cells, but not in p53-/- cells, RAD51 protein level decreased 48 h post irradiation and fluorescence immunostaining showed resolution of RAD51 foci and relocalization of RAD51 to nucleoli at time points corresponding to the decrease in RAD51 protein level. Both cell lines rejoined DNA double strand breaks efficiently with similar kinetics and p53 status did not influence sensitivity to DNA damaging agents. We suggest that p53 has a role in RAD51 clearance post DSB repair and that nucleoli might be sites of RAD51 protein degradation

Promotion of Homologous Recombination and Genomic Stability byRAD51AP1 via RAD51 Recombinase Enhancement

Energy Technology Data Exchange (ETDEWEB)

Wiese, Claudia; Dray, Eloise; Groesser, Torsten; San Filippo,Joseph; Shi, Idina; Collins, David W.; Tsai, Miaw-Sheue; Williams,Gareth; Rydberg, Bjorn; Sung, Patrick; Schild, David

2007-04-11

Homologous recombination (HR) repairs chromosome damage and is indispensable for tumor suppression in humans. RAD51 mediates the DNA strand pairing step in HR. RAD51AP1 (RAD51 Associated Protein 1) is a RAD51-interacting protein whose function has remained elusive. Knockdown of RAD51AP1 in human cells by RNA interference engenders sensitivity to different types of genotoxic stress. Moreover, RAD51AP1-depleted cells are impaired for the recombinational repair of a DNA double-strand break and exhibit chromatid breaks both spontaneously and upon DNA damaging treatment. Purified RAD51AP1 binds dsDNA and RAD51, and it greatly stimulates the RAD51-mediated D-loop reaction. Biochemical and cytological results show that RAD51AP1 functions at a step subsequent to the assembly of the RAD51-ssDNA nucleoprotein filament. Our findings provide the first evidence that RAD51AP1 helps maintain genomic integrity via RAD51 recombinase enhancement.

The effect of gamma irradiation on fertile eggs and hatched chick performance

International Nuclear Information System (INIS)

Mekkawy, S.H.

1995-01-01

Two handier fertile white arber acers eggs were exposed to gamma irradiation (Co 6 0) at the following levels 0, 100, 150 and 200 rad. They Were then hatched with the control eggs and hatchability, growth rate, feed consumption, feed conversion, carcass quality, carcass analysis and the blood analysis were determined. Hatchability was reduced gradually with increased radiation, but significantly, no differences in body weight between irradiated and control chicks were apparent at hatching time. At the end of the experimental 45 days, the mean heavight was that of the irradiation dose of 150 rad. The feed conversion efficiency was enhanced by the irradiation treatments, especially with the dose of 200 rad. There were no differences in the carcass quality and carcass composition between the treated and non-treated birds. The results demonstrated that, the irradiation treatments had no effects on the blood analysis of the birds. 7 tabs

The effect of embryonal thymic calf extracts on neonatally thymectomized mice and on mice lethally irradiated with gamma rays

International Nuclear Information System (INIS)

Czaplicki, J.; Blonska, B.; Stec, L.

1981-01-01

The effect of embryonal thymic calf extracts (ETCE) on mice thymectomized at birth was investigated. ETCE was found to induce an increase in leukopenia and decrease in the level of serum gamma globulins; it also reduced survival time in mice. The effect of ETCE on lethally irradiated mice was also examined. Only long-term administration of ETCE prior to gamma irradiation at 750 rad prolonged the survival time of mice (40% permanent survival) as compared with irradiated controls; the leukocytes from mice retained mitotic capability. Neither long-term treatment with ETCE prior to irradiation at 1000 rad, nor short-term administration prior to 750 rad affected survival time. ETCE administered after irradiation of mice with 750 rad caused a rapid decrease in blood leukocytes and a significantly lowered survival time. (Auth.)

Dosimetric properties of the pocket alarm dosimeter type Alnor RAD 21L, RAD 21H, RAD 22

International Nuclear Information System (INIS)

Hauser, M.; Burgkhardt, B.; Piesch, E.

1981-02-01

In personnel monitoring pocket dosimeters with build-in alarm devices are increasingly in use. The report presents results of a test performed at Karlsruhe for the pocket dose and alarm meter type Alnor RAD 21L, RAD 21H, RAD 22. The properties investigated are above all linearity and reproducibility of the dose reading as well as of the acoustic alarm indication, dependence of the dose reading on the photon energy, the direction of the radiation incidence, the dose rate, the temperature, operational characteristic of the batteries. (orig.) [de

Cranial irradiation in children with lymphoblastic acute leukemia: results and damages

International Nuclear Information System (INIS)

Cecchetti, E.; Brandoli, V.

1979-01-01

From 1973 to 1976, 81 children with lymphoblastic acute leukemia were treated with cranial prophylactic irradiation at the Istituto di Radioterapia ''L. Galvani'' del'Universita di Bologna. We divided the patients into 6 groups according to different characteristics. At the beginning of 1978 the survival rate was 82%; 60 patients (74%) were in complete continuous remission. We studied the encephalic post irradiation syndrome that is present in children over 2 years of age only when doses are higher than 2500 rad and in children under 2 years of age when doses exceed 2000 rad. This complication occurs frequently in the experience of other authors; however, it is absent under certain doses with which it is possible to obtain the same good results. We feel that among the different techniques and methods, the best radiological treatment is daily bilateral cranial irradiation for patients early in remission; we recommend doses of 2400 rad for children above 2 years of age and 1950 rad for those under 2 years

Comparison of the effect between an active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue and that using irradiated tumor cells

International Nuclear Information System (INIS)

Ogawa, Yasuhiro; Maeda, Tomoho; Yoshida, Shoji; Yamamoto, Yoichi; Morita, Masaru

1983-01-01

The effect of the active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was compared with that of irradiated (10,000 rads) tumor cells on the transplanted MM46 tumor of female C3H/He mice after radiotherapy. MM46 tumor cells were inoculated into the right hind paws of mice. On the 6th day, irradiation with a dose of 3,000 rads was performed. On the 14th day, tumor cells and concomitant mononuclear cells which were separated from the low-dose irradiated tumor tissue (2,000 rads on the 6th day) were injected into the left hind paws of one group of the tumor-bearing mice. On the same day, irradiated MM46 tumor cells were injected into the left hind paws of another group of the tumor-bearing mice. Effectiveness of these two methods of active specific immunotherapy against tumor was evaluated by the regression of tumor and survival rate of mice. The active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was far more effective than irradiated tumor cells on this tumor system involved. (author)

Activation of lysosomal enzymes and tumour regression caused by irradiation and steroid hormones

International Nuclear Information System (INIS)

Ball, A.; Barratt, G.M.; Wills, E.D.

1982-01-01

The lysosomal enzyme activity and membrane permeability of mouse C3H mammary tumours has been studied using quantitative cytochemical methods following irradiation of the tumours with doses of 1500, 3500 or 6000 rad ν rays. No change in the lysosomal enzyme activity was observed immediately after irradiation, but increased enzyme activity and increased membrane permeability were observed 24 hr after irradiation with doses of 3500 or 6000 rad. Twenty-four hours after injection of prednisolone there was a marked increase of lysosomal membrane permeability and enzyme activity, and injection of prednisolone soon after irradiation enhanced the effect of irradiation. After a dose of 6000 rad and prednisolone, the lysosomal membrane permeability increased to 191% of the control and the enzyme activity to 326% of the value of the control tumours. Measurement of tumour size after irradiation or after a combined treatment with irradiation and prednisolone showed that a close correlation exists between tumour regression and lysosomal enzyme activity. The experiments support the view that lysosomal enzymes play an important role in tumour regression following irradiation. (author)

Irradiation spine deformity in children treated for neuroblastoma

International Nuclear Information System (INIS)

Mayfield, J.K.; Riseborough, E.J.; Nehme, M.

1978-01-01

A retrospective long-term follow-up review of 56 children with neuroblastoma surviving five years and longer following treatment since 1946 revealed that 57% had developed spine deformity (S.D.) following treatment with 250 kilovolt irradiation at the time of review. The average age at diagnosis was 17 months. Irradiation therapy was delivered to most children before 24 months of age. Follow-up averaged 12.9 years with a range of 5-31 years. Eighty-five per cent of the children had developed structural spine deformity at skeletal maturity and 54% of these children had scoliosis greater than 20 degrees. Sixteen per cent of irradiated children developed structural kyphosis. Non-midline opposing anterior and posterior ports were used most frequently. Mean dosage in patients who developed scoliosis of 20 degrees or more was 3588 rads (spine dosage) and 3746 rads in patients who developed kyphosis. Irradiation through opposing anterior and posterior ports was more commonly associated with the development of S.D. Sixty-six per cent of children who had more than 2000 rads developed S.D. The adolescent growth spurt was associated with an increase in the frequency and severity of spine deformity. This study indicated that moderate to severe S.D. was produced by irradiation in excess of 2000 rads administered with a 250-kilovoltage machine. This study would also suggest that children with neuroblastoma treated with orthovoltage irradiation should be followed closely by the orthopaedic surgeon, the oncologist, the radiotherapist and the paediatrician until the completion of skeletal growth for the development of unsightly structural spine deformity. Early bracing and surgery may be helpful in controlling these deformities in the pre-adolescent to early adolescent years. Continued observation is necessary to determine if current irradiation techniques will minimize or eradicate the incidence and severity of these complications. (author)

Neuronal damage in chick and rat embryos following X-irradiation

International Nuclear Information System (INIS)

Schneider, B.F.; Norton, S.

1980-01-01

Exposure of rat and chick embryos to X-irradiation at the time of development of neurons at the telencephalic-diencephalic border results in prolonged damage to neurons in this area as measured by neuronal nuclear size. A dose of 100 rads to the seven-day-old chick embryo has about the same effect as 125 rads to the 15-day-old rat fetus. The nuclear volume of large, multipolar neurons in the chick paleostriatum primitivum and the rat lateral preoptic area are reduced from 10 to 15%. Larger doses of X-irradiation to the chick (150 and 200 rads) cause progressively greater reductions in nuclear size. The large neurons which were measured in the rat and chick are morphologically similar in the two species. Both contain cytoplasmic acetylcholinesterase and have several branched, spiny dendritic processes. The similarity of response of chick and rat neurons to X-irradiation diminishes the significance of maternal factors as the cause of the effects of fetal irradiation in these experiments

Variation in the hematocrit of the rat after gamma irradiation

International Nuclear Information System (INIS)

Marble, G.; Breuil, L.; Berthelet, J.

1966-01-01

Statistical analysis of hematocrit measurement results has been carried out for twenty batches of rats with a view to studying the variation in the hematocrit as a function of the irradiation dose during the first four days after this irradiation. A significant increase in the hematocrit has been observed on the third day for 750 and 1000 rads and on the fourth day for 1000 rads only. (authors) [fr

Splenic irradiation in myelofibrosis. Clinical findings and ferrokinetics

International Nuclear Information System (INIS)

Parmentier, C.; Charbord, P.; Tibi, M.; Tubiana, M.

1977-01-01

Nine patients were submitted to splenic or, in two cases, hepatosplenic irradiation; these patients presented a primary myelofibrosis or a spent polycythemia vera characterized by splenomegaly, anemia, and occasionally leucocytosis and thrombocytopenia. The hematological condition returned to normal in 2 patients. This improvement lasted 4 years after a first series of irradiation. The recurrence of splenomegaly and anemia indicated a second series of irradiation, the results of which were as good as those of the first series. Ineffective medullary and splenic erythropoiesis without preeminent aplasia appeared to be correlated with a beneficial effect of splenic irradiation. Absence of hepatomegaly and marked leucocytosis were less important prognostic factors. The modee of action of radiotherapy and the way in which it differs from splenectomy are discussed. The irradiation delivered moderate doses (450 rad in 18 sessions of 25 rad). Hepatic irradiation did not appear to be essential even in cases of intense hepatic myeloid metaplasia: in 2 patients liver erythropoiesis regressed when the spleen alone was irradiated

Effect of gamma irradiation on the hatchability and embryonic development of quail eggs

International Nuclear Information System (INIS)

Oroszlany, P.; Sinkovicsne Hlubik, I.

1979-01-01

The effect of different doses of gamma irradiation on the embryonic development of quail and hen's eggs was examined. The goals of the examinations were to determine the LD 50 and LD 100 values, to establish the effect of single and multiple irradiation on embryonic development and to get some information on the embryonation of eggs produced by quails and their progeny grown from irradiated eggs. It was shown that 200 rad dose has significant stimulation effect of the hatching results of quail eggs. The LD 50 and LD 100 values were about 800 to 850 rad and 1600 rad, respectively. Repeated irradiation on the progeny-generations proved to be unambiguously deleterious on embryonation. High doses changed the rhythm of embryonal mortality, showing a peak under the irradiation and in the first three days of incubation, and significantly enhanced the number of teratological types. (author)

Influence of whole-body irradiation on calcium and phosphate homeostasis in the rat

International Nuclear Information System (INIS)

Pento, J.T.; Kenny, A.D.

1975-01-01

Previous irradiation studies have revealed marked alterations in calcium metabolism. Moreover, the maintenance of calcium homeostasis with parathyroid hormone or calcium salts has been reported to reduce radiation lethality. Therefore, the present study was designed to evaluate the influence of irradiation on calcium homeostasis in the rat. Nine hundred rad of whole-body irradiation produced a significant depression of both plasma calcium and phosphate at 4 days postirradiation. This effect of irradiation was observed to be dose-dependent over a range of 600 to 1200 rad, and possibly related to irradiation-induced anorexia. The physiological significance of these observations is discussed

Induced mutation In Nelumbo nucifera Gaertn. by gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Lama, Sainiya; Aeksomtramaet, Ladda; Kanchanapoom, Kamnoon [Department of Biology, Faculty of Science, Prince of Songkla University, Songkhla (Thailand)

2005-10-15

Lotus (Nelumbo nucifera Gaertn.) seeds were exposed to different levels of Gamma irradiation at 0, 2, 4, 6, 8 and 10 Kilo rad. The exposed embryos were cultured on solid M S medium supplemented with 2 mg/l B A and overlaid with a liquid M S medium without growth regulators for 1 month. It was found that 50% growth reduction (GR50) was at 6 Kilo rad. The plant lets were subcultured twice every 2 months then they were transferred to solid M S medium supplemented with 4 mg/l NAA and overlaid with M S medium without growth regulators for root induction. The results revealed that plant lets in the control treatment (not exposed to Gamma irradiation) had the highest shoot growth and adventitious root formation. Plant lets at 2-Kilo rad treatment showed the second highest growth. The plant lets at 4-Kilo rad treatment did not exhibit adventitious root formation and had abnormal characteristics. Treatments at 6-10 Kilo rad inhibited the growth of the plant lets.

Induced mutation In Nelumbo nucifera Gaertn. by gamma irradiation

International Nuclear Information System (INIS)

Lama, Sainiya; Aeksomtramaet, Ladda; Kanchanapoom, Kamnoon

2005-10-01

Lotus (Nelumbo nucifera Gaertn.) seeds were exposed to different levels of Gamma irradiation at 0, 2, 4, 6, 8 and 10 Kilo rad. The exposed embryos were cultured on solid M S medium supplemented with 2 mg/l B A and overlaid with a liquid M S medium without growth regulators for 1 month. It was found that 50% growth reduction (GR50) was at 6 Kilo rad. The plant lets were subcultured twice every 2 months then they were transferred to solid M S medium supplemented with 4 mg/l NAA and overlaid with M S medium without growth regulators for root induction. The results revealed that plant lets in the control treatment (not exposed to Gamma irradiation) had the highest shoot growth and adventitious root formation. Plant lets at 2-Kilo rad treatment showed the second highest growth. The plant lets at 4-Kilo rad treatment did not exhibit adventitious root formation and had abnormal characteristics. Treatments at 6-10 Kilo rad inhibited the growth of the plant lets

The role of Rad 51 protein in radioresistance of spheroid model of Du 145 prostate carcinoma cell line

International Nuclear Information System (INIS)

Taghizadeh, M.; Khoei, S.; Nikoofar, A. R.; Ghamsari, L.; Goliaei, B.

2009-01-01

Rad 51 is a protein with critical role in double strand break repair. Down-regulation of this protein has a significant effect in radiosensitivity of some cell lines like prostate carcinoma. Compared to monolayer cell culture model, the spheroids are more resistant to radiation. The aim of the current study was to determine the Rad 51 protein level in Du 145 spheroids, and monolayer cells before and after exposure to gamma irradiation. Materials and Methods: In the present study, western blot was used to determine the level of Rad 51 protein in Du 145 cell line grown as monolayer and spheroid. Results: Western blot analysis showed that in the spheroid cells, Rad 51 had an elevated level before and after radiation in comparison with monolayer cells. Higher doses of radiation induced elevated expression of Rad 51 protein in both culture models.The level of at protein after exposure to gamma rays had been time-dependent. Conclusion: Rad 51 might act as a mediator of radiation resistance in tumor cells. Repression of Rad 51 activity could be a prominent strategy to overcome radiation resistance of tumors.

Effect of Low Dose gamma-ray Irradiation on the Germination and Growth in Red Pepper (Capcicum annuum L.)

International Nuclear Information System (INIS)

Lee Eun-Kyung; Kim Jae-Sung

1998-01-01

This study was conducted to determine the effect of low dose gamma-ray irradiation in red pepper. The germination percentage, plant, the number of flower, chlorophyll contents, leaf length and width were observed from plants grown with red pepper seeds irradiated with various low dose of gamma-ray. The germination percentage of irradiation group treatmented gamma-ray was much higher than that of the control. Specially the germination percentage after sowing red pepper seeds on paper towel was higher than 1,000 and 2,000 rad irradiation group. The height of plants grown with red pepper seeds irradiated with gamma-ray was increased in 100, 200 and 400 rad irradiation group compared to that of the control. The height of plant from 2,400 rad irradiation group, however, was shorter than that of the control. Nutrient contents of leaves of plants grown with red pepper seeds irradiated with various dose of gamma-ray were significantly increased in 800 and 1,200 rad irradiation group. Electric conductivity (EC) of the water used for seed germination was lower irradiation group than control group. Therefore, there was the possibility to increase the germination and plant growth with gamma-ray of adequate low dose

Irradiation of blood by 238Pu alpha particles

International Nuclear Information System (INIS)

Hungate, F.P.; Riemath, W.F.; Culver, G.G.; Gillis, M.F.; Ragan, H.A.

1976-01-01

A developmental 238 Pu blood irradiator produced no evidence of lymphopenia in a dog. Irradiation continued for a year at an estimated rate of about 100 rads/day, but this dosimetry is highly uncertain

A new phenomenon in the prenatal effects of harmful agents: total system teratogenesis

International Nuclear Information System (INIS)

Filyushkin, I.V.; Ignatov, A.N.

1997-01-01

Theoretical and experimental studies of the mechanism of induction of minor teratogenic effects were performed. Theoretical analysis of the mechanism of minor teratogenesis have utilized reliable facts, well established concepts of biomedical science, and also categories and language of the theory of complex systems. To check theoretical statement in the experiments 889 baby rats were obtained. Of them, 487 were prenatally irradiated with 2 Gy of gamma rays and 402 were nonirradiated controls. Indices of the CNS development indices of the immunity status development and indices of the endocrine development were studied along the course of postnatal development of prenatally irradiated rats comparatively to controls, with loading test also being used, such as sensitization with allogeneic protein, immobilization stress and acute irradiation. A mechanism through which prenatal exposure to radiation and any other agent affecting physical embryonic development leads to congenital CNS deficiencies is found theoretically and confirmed in animal experiment. In the frame of this mechanism, the ultimate effect of prenatal exposure to a deleterious agent is the distortion of the structure of the neuroimmunoendocrine regulation of a postnatal organism in the direction of the excessive development of is endocrine component and the (ontogenetically) successive coadaptive under development of nervous and immune components. 27 refs., 5 figs., 2 tabs

Study on antitussive effects of eprazinone dihydrochloride on radiation induced inflammation of upper respiratory tract due to postoperative irradiation of breast cancer

International Nuclear Information System (INIS)

Taoya, Koichiro

1977-01-01

Discussion was made of antitussive effects of Eprazinone hydrochloride (Resplen) on radiation induced inflammation of the upper respiratory tract in 15 cases irradiated after an operation of breast cancer. Depth dose at 3 cm was 200 rads/day, and 5000 rad/25 times/5 weeks was irradiated with telecobalt. Mainly abnormal sensation and pain in the throat and cough appeared and patients complained of suffering from a common cold, because a part of irradiation field included the throat, trachea, and esophagus. At the same time as manifestation of symptoms, 120 mg/day of Eprazinone Dihydrochloride was administered. In 8 cases, other drugs were added to, or irradiation schedule was changed because the symptoms were not improved or were exaggerated. The symptoms disappeared up to 5000 rad irradiation in one case, up to 4000 - 5000 rad irradiation in 4 cases, and up to 4000 rad irradiation in 2 cases. It is impossible to decide effective rate of this drug because of shortage of clinical cases, but it is suggested that there is a significance to increase cases treated successively with this drug in future. (Tsunoda, M.)

Study on antitussive effects of Eprazinone dihydrochloride on radiation--induced inflammation of upper respiratory tract due to postoperative irradiation of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Taoya, K [National Hospital of Yokohama (Japan)

1977-04-01

Discussion was made of the antitussive effects of Eprazinone hydrochloride (Resplen) on radiation-induced inflammation of the upper respiratory tract in 15 cases irradiated after an operation of breast cancer. Depth dose at 3 cm was 200 rads/day, and 5000 rad/25 times/5 weeks was irradiated with telecobalt. Mainly abnormal sensation and pain in the throat and cough appeared and patients complained of suffering from a common cold, because a part of irradiation field included the throat, trachea, and esophagus. At the same time as manifestation of symptoms, 120 mg/day of Eprazinone Dihydrochloride was administered. In 8 cases, other drugs were added to, or irradiation schedule was changed because the symptoms were not improved or were exaggerated. The symptoms disappeared up to 5000 rad irradiation in one case, up to 4000 to 5000 rad irradiation in 4 cases, and up to 4000 rad irradiation in 2 cases. It is impossible to decide effective rate of this drug because of shortage of clinical cases, but it is suggested that there is a significance to increase cases treated successively with this drug in future.

Cranial irradiation of young rats impairs later learning and growth

International Nuclear Information System (INIS)

Overmier, J.B.; Carroll, M.E.; Patten, R.; Krivit, W.; Kim, T.H.

1979-01-01

Young rats (26 days) were exposed to ionizing radiation of the head of 0, 1200, 2400 or 3000 rads total in 200 rads/day doses. The subsequent growth of irradiated rats was permanently impaired: such impairment was positively related to amount of irradiation. Beginning in adolescence, rats were trained on a horizontal/vertical visual discrimination in a runway task and although all four groups mastered the discrimination, they differed in their patterns of acquisition. These results indicated long term effects and are associated with a cranial irradiation regimen similar to that given to children suffering acute lymphocytic leukemia (ALL). (author)

Effect of irradiation on human T-cell proliferation: low dose irradiation stimulates mitogen-induced proliferation and function of the suppressor/cytotoxic T-cell subset

International Nuclear Information System (INIS)

Gualde, N.; Goodwin, J.S.

1984-01-01

Unfractionated human T cells exposed to 10-50 rad of X irradiation incorporated less [ 3 H]thymidine than nonirradiated T cells when subsequently cultured with PHA or Con A. The cytotoxic/suppressor T-cell subset, isolated as either OKT8(+) or OKT4(-) cells, demonstrated significantly enhanced [ 3 H]thymidine incorporation in PHA- or Con A-stimulated cultures after exposure to 10-50 rad, compared to unirradiated cells, while the proliferation of the OKT4(+) helper/inducer subset was inhibited by low dose irradiation. It has been previously reported that approximately 30% of the cytotoxic/suppressor subset also stains with OKM1. When the cytotoxic/suppressor subset was further subdivided into OKT4(-), OKM1(+), and OKT4(-), OKM1(-) cells, proliferation of the OKT4(-), OKM1(+) population was inhibited by exposure to 25 rad while proliferation of the OKT4(-), OKM1(-) population was stimulated. The increase in proliferation of the cytotoxic/suppressor T-cell subset after low dose irradiation is paralleled by an increase in suppressor activity of these cells. T cells exposed to 25 rad and then cultured with Con A for 48 hr caused greater inhibition of IgG production when added to fresh autologous lymphocytes stimulated by pokeweed mitogen than did unirradiated cells. Thus, low dose irradiation enhances both the proliferation and function of the human suppressor T-cell subset

Roles of Rad51 protein in homologous recombination in mammalian cells: relation with repair, replication and cell cycle

International Nuclear Information System (INIS)

Lambert, S.

2001-01-01

Homologous recombination (HR) is a fundamental process, allowing a faithful repair. In mammalian, MmRAD51, which is the homologue of Saccharomyces cerevisiae ScRAD51 key protein for HR, is an essential gene. This work is based on the characterisation of viable hyper and hypo-recombinant cell lines specifically affected in the Rad51 pathway. By expressing wild type and dominant negative forms of MmRad51, we demonstrated that Rad51 pathway participates to the repair by HR to induced DNA damages. However, inhibition of the Rad 51 pathway does not affect cell viability, spontaneously or after irradiation, whereas, radiation induced HR is inhibited. In the presence of DNA damages during late S and G2/M phase, inhibition of Rad51 pathway induced chromosomal aberrations, leading to a transient arrest in mitosis. This arrest is associated with an increased of cell death. However, a fraction of cells can escape from this transient arrest by forming tetraploid cells, associated with an absence of chromalid separation. Thus, in response to impaired Rad51 pathway, mitotic checkpoints seems to play an essential role. In line with this, we showed that the essential function of Rad51 is p53-dependent, which is in agreement with the role of p53 in tetraploidy inhibition. Our results suggest that the Rad51 protein could participate to the control of mitotic checkpoints and thus to the maintenance of genetic stability. This function could involve other Rad51 partners such as the tumour suppressors BRCA1, BRCA2 and p53. (author) [fr

RadCon: A radiological consequences model. Technical guide - Version 2.0

International Nuclear Information System (INIS)

Crawford, J; Domel, R.U.; Harris, F.F.; Twining, J.R.

2000-05-01

A Radiological Consequence model (RadCon) is being developed at ANSTO to assess the radiological consequences, after an incident, in any climate, using appropriate meteorological and radiological transfer parameters. The major areas of interest to the developers are tropical and subtropical climates. This is particularly so given that it is anticipated that nuclear energy will become a mainstay for economies in these regions within the foreseeable future. Therefore, data acquisition and use of parameter values have been concentrated primarily on these climate types. Atmospheric dispersion and deposition for Australia can be modelled and supplied by the Regional Specialised Meteorological Centre (RSMC, one of five in the world) which is part of the Bureau of Meteorology Research Centre (BMRC), Puri et al. (1992). RadCon combines these data (i.e. the time dependent air and ground concentration generated by the dispersion model or measured quantities in the case of an actual incident) with specific regional parameter values to determine the dose to people via the major pathways of external and internal irradiation. For the external irradiation calculations, data are needed on lifestyle information such as the time spent indoors/outdoors, the high/low physical activity rates for different groups of people (especially critical groups) and shielding factors for housing types. For the internal irradiation calculations, data are needed on food consumption, effect of food processing, transfer parameters (soil to plant, plant to animal) and interception values appropriate for the region under study. Where the relevant data are not available default temperate data are currently used. The results of a wide ranging literature search has highlighted where specific research will be initiated to determine the information required for tropical and sub-tropical regions. The user is able to initiate sensitivity analyses within RadCon. This allows the parameters to be ranked in

Enzymatic collection test as total gamma irradiation pronostic test in rat, rabbit and man

International Nuclear Information System (INIS)

Breuil, G.; Dinnequin, B.

The purpose of this study is to known, during 30 days, what becomes the animal whose enzymatic co-ordinates are well known. Both 100, 160, 200, 325, 400, 650, 850, 975, 1000, 1300 rads irradiated rabbit serum enzymatic evolution and that of two 1000 rads in toto irradiated leucemic men for a cord graft are studied [fr

The biochemical changes of bone collagen after high-dose irradiation

International Nuclear Information System (INIS)

Tajiri, Ken

1980-01-01

In our clinic, patients with malignant bone tumors have been treated by high-dose irradiation therapy, 10,000-20,000 rads, for primary lesions. In order to study the biochemical changes of normal bone around tumor tissue, especially bone collagen, after high-dose irradiation, the author performed the following experiments. The right knee joint of rabbits was irradiated with either 6,000, 10,000, or 15,000 rads by 60 Co-γ ray. The cortical bone of the right tibial metaphysis was used for analyses and compared with the left tibia of the same rabbit. These studies were followed for one year after the final irradiation. The calcium, phosphorous and collagen contents of irradiated bone were remarkably changed. These data indicate that collagen biosynthesis of irradiated bone was decreased and the calcification was disturbed. An increase in the amount of total soluble collagen and a decrease in the amount of hydroxylysine bound sugar were observed. The ratio of β to α chains of the collagen molecule was also changed by the irradiation. The amount of reducible cross-links per hydroxyproline residue was strikingly increased three months after the final irradiation. These changes were remarkable especially in the 10,000 and 15,000 rads irradiated group and found to be recovered approximately six months to one year after the final irradiation. These findings indicate that high-dose irradiation reduces the stability of bone collagen both with the destruction of sugar bonds of hydroxylysine residues and the replacement of matured collagen matrix to immatured one which contain mostly labile reducible cross-links. (author)

Biological effects after prenatal irradiation (embryo and fetus) ICRP Publication 90 Approved by the Commission in October 2002

Energy Technology Data Exchange (ETDEWEB)

Valentin, J

2003-06-01

In its 1990 recommendations, the ICRP considered the radiation risks after exposure during prenatal development. This report is a critical review of new experimental animal data on biological effects and evaluations of human studies after prenatal radiation published since the 1990 recommendations. Thus, the report discusses the effects after radiation exposure during pre-implantation, organogenesis, and fetogenesis. The aetiology of long-term effects on brain development is discussed, as well as evidence from studies in man on the effects of in-utero radiation exposure on neurological and mental processes. Animal studies of carcinogenic risk from in-utero radiation and the epidemiology of childhood cancer are discussed, and the carcinogenic risk to man from in-utero radiation is assessed. Open questions and needs for future research are elaborated. The report reiterates that the mammalian embryo and fetus are highly radiosensitive. The nature and sensitivity of induced biological effects depend upon dose and developmental stage at irradiation. The various effects, as studied in experimental systems and in man, are discussed in detail. It is concluded that the findings in the report strengthen and supplement the 1990 recommendations of the ICRP.

RadConEd: A Graphical Data Editor for the Radiological Consequences Model, RadCon

International Nuclear Information System (INIS)

Crawford, J.; Domel, R.U.

2000-05-01

This document describes the application, RadConEd, which has been designed and implemented to enable users of the RadCon system to update these parameter files. The RadCon system is written in the Java programming language, and as such provides portability across computer platforms. The software described in this report was developed in line with the portability requirements of RadCon, thus providing a uniform user interface across computer platforms and bypassing the need of using system editors. In addition a number of data integrity measures were implemented

Teratogenic effect of Californium-252 irradiation in rats

International Nuclear Information System (INIS)

Satow, Yukio; Lee, Juing-Yi; Hori, Hiroshi; Okuda, Hiroe; Tsuchimoto, Shigeo; Sawada, Shozo; Yokoro, Kenjiro

1989-01-01

The teratogenicity of Californium-252 (Cf-252) irradiation which generates approximately 70% 2.3 MeV fast neutron and 30% gamma rays was evaluated. A single whole body exposure of Cf-252 at various doses was given to pregnant rats on day 8 or 9 of pregnancy, followed by microscopic autopsy of the fetuses at the terminal stage of pregnancy to search for external and internal malformations. For comparison, pregnant rats were irradiated with various doses of Cobalt-60 (Co-60) standard gamma rays at the same dose rate (1 rad/min.). The doses were 20-120 rad of Cf-252 and 80-220 rad of Co-60. Using frequency of radiation induced malformations observed on day 8 of pregnancy as an index, relative biological effectiveness (RBE) of 2.3-2.7 was obtained from the straight line obtained by modifying by the least squares method the frequency curves of malformed fetuses in total implants and in surviving fetuses. The types of malformations induced by Cf-252 and Co-60 irradiation were alike. Using fetal LD 50 as an index, 2.4 was obtained as RBE when irradiated on day 8 of pregnancy and 3.1 as that when irradiated on day 9. The results showed that Cf-252 had stronger a teratogenic effect than Co-60 gamma rays. (author)

The effect of X-ray irradiation on a red cell component in WB, WRC and LPRC

International Nuclear Information System (INIS)

Tayama, Tatsuya; Toyota, Kuroh; Nagahashi, Hisakata; Masuyama, Tetsuya; Haneda, Kenji; Juji, Takeo.

1990-01-01

In spite of the use of X-ray irradiation on blood products, few data about its effect on components are reported. We need more informations about a quality of irradiated red cell components. This study shows in vitro changes of irradiated red cell component in WB, WRC and LPRC as the minimum dose of 1,500, 3,000, and 5,000 rads. The fact as follows were observed in response to irradiated doses: 1) increased fragility of red cell membrane, 2) increased amount of plasma K and plasma Hb, and 3) decrease of ATP in WB.2,3-DPG, glucose, pH, Ht and Cl. The numbers of RBC, WBC and Platelet were not affected by irradiation with doses between 1,500 and 5,000 rads. According to these results, the followings are recommended: 1) irradiation with 1,500 rads is a proper method for WB, 2) in order to avoid the risk of increased plasma K, WB should be used within 1 week after irradiation, and WRC and LPRC should be used 24 hours after irradiation. (author)

Effects of gamma irradiation on histomorphology of some endocrine glands of the rain quail, Coturnix coromandelica (Gmelin)

International Nuclear Information System (INIS)

Deshmukh, B.D.; Suryawanshi, S.A.

1989-01-01

Effects of single, whole-body 60 Co-gamma irradiation in different doses (250 rad to 15 k rad) on histology of thyroid, adrenal and pancreatic islets of the rain quail were studied. A low dose of 250 rad failed to evoke any change in histology of the glands studied. Doses of 500 rad and 1 k rad resulted in hypoactivity of thyroid but could not affect adrenal and pancreatic islets. Exposure to 1.5 k rad and higher doses caused hyperplasia and hypertrophy of thyroid and hypertrophy of adrenal gland. Thyroid was injured by heavy irradiation. Doses up to 3 k rad did not bring about any change in islet cells, however, higher doses resulted in degenerative changes in islet cells. α-islets were affected by 7 and 15 k rad but necrotic changes in β-islets were observed only after exposure to 15 k rad. The results indicate that thyroid is the most sensitive and pancreatic islet, highly resistant to gamma radiation. (author). 20 refs., 4 figs

The effect of 15 MeV electrons at different irradiation depth on the growth of HeLa cells

International Nuclear Information System (INIS)

Helmerking, B.

1975-01-01

The effect of fast electrons at relative depth doses of 100% and 30% with energy doses of 100 to 400 rad and a dose rate of 200 rad/min on HeLa cells was analyzed. For the evaluation of the irradiation effect, the cell count of irradiated cultures compared with the cell count of not irradiated cultures 16 d after irradiation. The determination of the cell numbers and thus the determination of the counting multiplication rate of the cells was done by isolated cell nuclei with a counter tube and a counter chamber. Irradiation of the cells took place in the plateau phase of the growth curve. After irradiation with a relative depth dose of 100% as well as of 30%, a decrease of the cell number of the cultures can be observed on the 16th day. After irradiation with 200 rad in 100%-depth a survival rate of 72% is found and in 30% depth a survival rate of 60%. At 300 rad the values are 44% for 100% depth, and 30% for 30% depth. For 400 rad the survival rate is 11% at 100% depth and 5% at 30% depth. On the basis of the above-mentioned values the survival rate after irradiation with 30% relative depth dose at the energy doses 200, 300 and 400 rad is increasingly less in comparison with the irradiation with 100% relative depth dose. In the range of 200 to 400 the RBW of the 100% depth in comparison with the 30% depth is constant with a value of 0.88 +- 0.03. The determination of the cell count of a culture by counting isolated nuclei, which is a new method of assessing an irradiation effect is discussed. The significance of this new criterion is compared with the known method of colony counting. The results are compared with results of other works using method of colony counting, and are discussed. (orig./MG) [de

Experimental investigations into the effects of irradiation with neutron and gamma rays on the immune system, as demonstrated at the model of immunity of Salmonella typhimurium on the mouse

International Nuclear Information System (INIS)

Hahn, H.

1985-01-01

Mice were irradiated with neutron and gamma rays (with a dose of 200 rad respectively 300 rad). Either 24 hours before or after the irradiation the mice were vaccinated and revaccinated with a Salmonella typhimurium vaccine. By ELISA, IHA and BTZD-test specific antibodies against Salmonella typhimurium could be found. The 200 rad irradiated animals had a lower increase in the formation of antibodies compared with mice not irradiated, if the irradiation was applied before the immunisation. On the 300 rad irradiated animals a reduction of the formation of the antibodies could be observed, too. The antibody titres, however, were higher and an earlier increase of the number of the antibodies was found in comparison with the 200 rad irradiated animals. A second antigene application after 7 days and an irradiation after the first respectively the second immunisation gave no noticeable proof of immune suppression. In our tests it was found out, that for the definition of the antibody titres of the sera the ELISA and the IHA had been more sensitive than the BTZD-test. (orig./MG) [de

G2 block in Chinese hamster cells induced by x-irradiation, hyperthermia, cycloheximide, or actinomycin-D

International Nuclear Information System (INIS)

Dewey, W.C.; Highfield, D.P.

1976-01-01

The entry of cells into mitosis was monitored by shaking off mitotic cells from monolayer cultures. The location in G 2 of the x-ray transition point (TP), beyond which the cells were not delayed by x irradiation moved closer to mitosis as the dose was increased, i.e., at 10 min before prophase for 100 to 200 rad, and at 19 min for 30 to 60 rad. Treatment with cycloheximide (CH, 20 μg/ml) at the time of irradiation (50 to 100 rad) shifted the TP for x irradiation by 5 to 9 min toward mitosis. Calculations from these shifts in TP with radiation dose indicated that the logarithm of both the fraction of cells in G 2 not delayed by irradiation and the fraction beyond the TP for CH (located at 26 min before phophase for 5 to 50 μg/ml) not delayed by irradiation decreased linearly with dose (anti D 0 of 30 rad). Furthermore, inhibition of protein synthesis by CH, with or without a simultaneous treatment with actinomycin D (AMD), prevented repair of damage causing mitotic delay for a period of time equal to the duration of the CH treatment

Response of the adrenal medulla to exogenous insulin in head X-irradiated dogs

International Nuclear Information System (INIS)

Yamashita, K.; Mieno, M.; Shimizu, T.

1976-01-01

The observed results on the secretory response of the adrenal medulla to exogenous insulin in dogs whose heads had been irradiated with 200 rad X-irradiation at a rate of 60.6 rad/min are reported. Approximately 20 h after irradiation 2 i.u. insulin/kg body weight was administered to both irradiated and control (non-irradiated) dogs. The secretion of both adrenaline and noradrenaline in five control dogs which received insulin had increased markedly 30 min after the injection and it was sustained over the first 120 min. Five irradiated dogs also responded to the injection of insulin by secreting appreciable amounts of both adrenaline and noradrenaline, but the responsiveness was considerably lower; adrenaline and noradrenaline secretion 30 and 60 min after the injection was 59 and 33% less than that caused by insulin in control animals respectively, and these differences were significant (P < 0.01). Since insulin induces hypoglycaemia and thereby leads to an increase in the adrenal medullary secretion through the central mechanism, the present results observed 1 day after X-irradiation of the head indicate that the susceptibility of the adrenomedullary activating mechanism in the central nervous system may be diminished considerably after X-irradiation, even at doses as low as 200 rad. (U.K.)

Response of the adrenal medulla to exogenous insulin in head X-irradiated dogs

Energy Technology Data Exchange (ETDEWEB)

Yamashita, K; Mieno, M; Shimizu, T [Nagasaki Univ. (Japan). School of Medicine

1976-12-01

The observed results on the secretory response of the adrenal medulla to exogenous insulin in dogs whose heads had been irradiated with 200 rad X-irradiation at a rate of 60.6 rad/min are reported. Approximately 20 h after irradiation 2 i.u. insulin/kg body weight was administered to both irradiated and control (non-irradiated) dogs. The secretion of both adrenaline and noradrenaline in five control dogs which received insulin had increased markedly 30 min after the injection and it was sustained over the first 120 min. Five irradiated dogs also responded to the injection of insulin by secreting appreciable amounts of both adrenaline and noradrenaline, but the responsiveness was considerably lower; adrenaline and noradrenaline secretion 30 and 60 min after the injection was 59 and 33% less than that caused by insulin in control animals respectively, and these differences were significant (P < 0.01). Since insulin induces hypoglycaemia and thereby leads to an increase in the adrenal medullary secretion through the central mechanism, the present results observed 1 day after X-irradiation of the head indicate that the susceptibility of the adrenomedullary activating mechanism in the central nervous system may be diminished considerably after X-irradiation, even at doses as low as 200 rad.

The Pathological Changes of Stomach in Experimental Rats following Single Irradiation of Supervoltage

International Nuclear Information System (INIS)

Choi, Myung Sun; Suh, Won Hyuck

1984-01-01

The pathological changes of stomach of the rat following 1,000 rad and 1,800 rad single exposure by Cobalt-60 has been made with 50 experimental rats. The dose of 1,000 rad and 6,000 rad in 6 weeks. Following single exposure, the groups of rat were terminated in 1, 2, 4, 8, 12 weeks intervals and the stomach were fixed to formalin solution immediately after dissection. The pathological changes were as follows: 1. Following 1,000 rad single exposure, the stomach show only mild to moderate submucosal edema in 4, 8, 12 weeks group. 1 and 2 weeks group show no changes. 2. Following 1,800 rad single exposure, 32%(8/25) of rats were dead by radiation effect and all other groups of stomach revealed variable pathological changes such as submucosal edema, squamous dysplasia, squamous papilloma as well as squamous cell carcinoma. 3. Optimal tolerance dose to the stomach was 4,500-5,000 rad when irradiation given by supervoltage. The entire stomach was included within the irradiation field, the dose to the stomach should not exceed 6,000 rad. 4. In conclusion, the radiation injury to the stomach were more direct radiation effects to the gastric mucosa rather than secondary changes of radiation injured vessels

The KYxxL motif in Rad17 protein is essential for the interaction with the 9–1–1 complex

Energy Technology Data Exchange (ETDEWEB)

Fukumoto, Yasunori, E-mail: fukumoto@faculty.chiba-u.jp [Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675 (Japan); Ikeuchi, Masayoshi; Nakayama, Yuji [Department of Biochemistry & Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414 (Japan); Yamaguchi, Naoto, E-mail: nyama@faculty.chiba-u.jp [Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675 (Japan)

2016-09-02

ATR-dependent DNA damage checkpoint is the major DNA damage checkpoint against UV irradiation and DNA replication stress. The Rad17–RFC and Rad9–Rad1–Hus1 (9–1–1) complexes interact with each other to contribute to ATR signaling, however, the precise regulatory mechanism of the interaction has not been established. Here, we identified a conserved sequence motif, KYxxL, in the AAA+ domain of Rad17 protein, and demonstrated that this motif is essential for the interaction with the 9–1–1 complex. We also show that UV-induced Rad17 phosphorylation is increased in the Rad17 KYxxL mutants. These data indicate that the interaction with the 9–1–1 complex is not required for Rad17 protein to be an efficient substrate for the UV-induced phosphorylation. Our data also raise the possibility that the 9–1–1 complex plays a negative regulatory role in the Rad17 phosphorylation. We also show that the nucleotide-binding activity of Rad17 is required for its nuclear localization. - Highlights: • We have identified a conserved KYxxL motif in Rad17 protein. • The KYxxL motif is crucial for the interaction with the 9–1–1 complex. • The KYxxL motif is dispensable or inhibitory for UV-induced Rad17 phosphorylation. • Nucleotide binding of Rad17 is required for its nuclear localization.

Effects of neutron irradiation on red blood cell labeling with technetium-99m

International Nuclear Information System (INIS)

Eng, R.R.; Conklin, J.J.; Grissom, M.P.

1982-01-01

The effects of in vivo and in vitro neutron irradiation on red blood cell radiolabeling with technetium-99m (Tc-99m) were studied. Blood from three dogs was irradiated with neutrons (725 rads, free in air dose) followed by radiolabeling with Tc-99m. The three dogs were subsequently whole body, neutron irradiated (250 rads, midline dose); and blood samples were drawn for radiolabeling at 24, 48, 72 and 96 hours post-irradiation. Blood from three control dogs was also drawn and radiolabeled on each day for comparison. The results show that there were no significant differences between the radiolabeling capacities of in vivo or in vitro neutron irradiated and control RBCs

Late vascular effects in irradiated mice brain

International Nuclear Information System (INIS)

Yoshii, Yoshihiko; Maki, Yutaka; Phillips, T.L.

1982-01-01

The whole brains of mice were irradiated with 250 kVp X-ray at 120 rad min -1 (1.6 mm Cu HVL, TSD 50 cm) and a histological study was done. The dose range of X-irradiation was from 1300 to 2500 rads. i.e., 1300, 1500, 1750, 2000, and 2500 rads. In the microscopic examination, the mice were killed at the regular postirradiation intervals of between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. A histological examination was performed by a morphometric estimation of vascular lesion in which the degree of the damage to the arterial system was scored through whole serial brain sections. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectatic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large artery were observed. Incidence of the fibrinoid necrosis increased dose dependently between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 - 87 weeks and can be used to quantify the vessel injury and a fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis. (author)

Sterility among female lizards (Uta stansburiana) exposed to continuous γ irradiation

International Nuclear Information System (INIS)

Turner, F.B.; Medica, P.A.

1977-01-01

A natural population of the lizard Uta stansburiana occupying a fenced 9-ha area in southern Nevada was exposed to essentially continuous γ irradiation from an arificial source between February 1964 and September 1973. Tissue doses were estimated using implanted lithium fluoride microdosimeters. Females became sterile as early as 11 months of age, but many were still fertile at ages of 20 months and a very few may have reproduced at 32 months. Dosimetry showed some females to be sterile after accumulated doses of around 500 rad, while others may have required 1000 or more rad. One female estimated to have received over 1200 rad was still reproductive. Irradiated females may pass through a state of half sterility, during which time they possess one functional ovary. Female U. stansburiana are sterilized at lower doses than the sterilizing dose (1500 rad) previously suggested for the leopard lizard, Crotaphytus wislizenii

Human cytomegalovirus replicates in gamma-irradiated fibroblasts

International Nuclear Information System (INIS)

Shanley, J.D.

1986-01-01

Because of the unique interdependence of human cytomegalovirus (HCMV) and the physiological state of the host cell, we evaluated the ability of human foreskin fibroblasts (HFF), exposed to gamma radiation, to support HCMV growth. Irradiation of HFF with 2,500 rADS prevented cellular proliferation and suppressed cellular DNA, but not RNA or protein synthesis. Treatment of HFF cells with 2,500 rADS 6 or 48 hours prior to infection did not alter the time course or virus yield during HCMV replication. Virus plaquing efficiency in irradiated cells was comparable to that of nonirradiated cells. As judged by thymidine incorporation and BUdR inhibition of virus replication, HCMV infection induced both thymidine kinase activity and host cell DNA synthesis in irradiated cells. In addition, virus could be recovered from HFF exposed to radiation 0-2 days after infection with HCMV. These studies indicate that the damage to cells by gamma irradiation does not alter the capacity of host cells to support HCMV replication

Analysis list: RAD21 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ncedbc.jp/kyushu-u/hg19/target/RAD21.1.tsv http://dbarchive.biosciencedbc.jp/kyushu...-u/hg19/target/RAD21.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/RAD21.10.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/RAD21.Blood.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/RAD21.Breast.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/RAD21.Dige...stive_tract.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/RAD21.Liver.tsv,http://dbarchive.bioscience

Recovery and radio-resistance in mice after external irradiation; Restauration et radio-resistance chez la souris apres irradiation externe

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Le Guillou, S [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1965-07-01

The author presents a literature study concerning recovery from external irradiation and an analysis of experimental data (which appear to suggest the idea of a radio-resistance in animals), as well as the hypotheses put forward for explaining this phenomenon. The author then describes an experiment carried out on mice whose LD 50/30 days increased from 1005 to 1380 rads and for which it was shown that an increase occurs in the number of certain anti-bodies circulating after a low dose of {gamma} irradiation. (author) [French] L'auteur presente une etude bibliographique de la restauration apres irradiation externe et une analyse des donnees experimentales qui paraissent suggerer la notion de radioresistance chez les animaux ainsi que les hypotheses cherchant a expliquer ce phenomene. Il relate ensuite une experience realisee sur des souris dont la DL 50/30 jours est passee de 1005 a 1380 rads et dans laquelle est montree l'augmentation de certains anticorps circulant apres une faible dose d'irradiation gamma. (auteur)

Early morphologic and quantitative changes in mouse peripheral blood lymphocytes after low dose gamma-irradiation

International Nuclear Information System (INIS)

Gitsov, L.; Byrneva, V.; Goranov, I.

1979-01-01

The study was undertaken in an effort to establish differences in the radiosensitivity of peripheral blood lymphocytes, as a possible test for evaluation of early and discrete radiation injury. Sexually mature mice of BAIB/c line were X-irradiated with doses of 50 and 250 rad. The animals were sacrificed by blood letting 24 hours after irradiation, but 30 minutes before this each mouse was heparinized. Smears were prepared from the enriched pooled leucocyte suspensions, obtained by dextran sedimentation of the red cells. The preparations were stained with toluidin blue by the methods of Smetana and Pappenheim. Cell size, clasmatosis, nucleolar structure and degree of cytoplasmic metachromasia were determined. It was found that the lymphocytogram of animals irradiated with 50 rad was characterized by high percentage of small lymphocytes, most of them with dispersed nuclear ribonucleoproteins and minimal clasmatose activity. Irradiation with 100 rad induced a characteristical rise in lymphocyte clasmatose activity and decrease in the number of small lymphocytes. The nucleoli were bright and well delineated. The lymphocytogram of animals irradiated with higher doses (150 and 250 rad) was characterized by predomination of large lymphocytes and hyperbasophilic forms with well preserved bright nucleoli. The percentage of lymphocates with clasmatosis was below the control value. (A.B.)

The RadAssessor manual

Energy Technology Data Exchange (ETDEWEB)

Seitz, Sharon L.

2007-02-01

THIS manual will describe the functions and capabilities that are available from the RadAssessor database and will demonstrate how to retrieve and view its information. You’ll learn how to start the database application, how to log in, how to use the common commands, and how to use the online help if you have a question or need extra guidance. RadAssessor can be viewed from any standard web browser. Therefore, you will not need to install any special software before using RadAssessor.

Roles of C-Terminal Region of Yeast and Human Rad52 in Rad51-Nucleoprotein Filament Formation and ssDNA Annealing.

Directory of Open Access Journals (Sweden)

Nilesh V Khade

Full Text Available Yeast Rad52 (yRad52 has two important functions at homologous DNA recombination (HR; annealing complementary single-strand DNA (ssDNA molecules and recruiting Rad51 recombinase onto ssDNA (recombination mediator activity. Its human homolog (hRAD52 has a lesser role in HR, and apparently lacks mediator activity. Here we show that yRad52 can load human Rad51 (hRAD51 onto ssDNA complexed with yeast RPA in vitro. This is biochemically equivalent to mediator activity because it depends on the C-terminal Rad51-binding region of yRad52 and on functional Rad52-RPA interaction. It has been reported that the N-terminal two thirds of both yRad52 and hRAD52 is essential for binding to and annealing ssDNA. Although a second DNA binding region has been found in the C-terminal region of yRad52, its role in ssDNA annealing is not clear. In this paper, we also show that the C-terminal region of yRad52, but not of hRAD52, is involved in ssDNA annealing. This suggests that the second DNA binding site is required for the efficient ssDNA annealing by yRad52. We propose an updated model of Rad52-mediated ssDNA annealing.

Acute transient radiation hepatitis following whole abdominal irradiation

Energy Technology Data Exchange (ETDEWEB)

Kim, T H; Panahon, A M; Friedman, M; Webster, J H [Roswell Park Memorial Inst., Buffalo, N.Y. (USA)

1976-10-01

Sporadic cases of radiation hepatitis have been reported following doses above 3500 rad delivered in 3 to 4 weeks to the liver. The authors report their experience of radiation hepatitis in two out of 117 consecutive lymphoma cases treated with total abdominal irradiation. These two patients developed clinically overt manifestations which lasted for a short period of time and fully recovered. The dose delivered to the whole liver was 3000 rad in six weeks, but in one an additional 1000 rad in five fractions were delivered to the left lobe in an attempt to boost the dose to the central axis lymphatic system up to 4000 rad. The low incidence of radiation hepatitis and its reversible course, when 3000 rad in six weeks are delivered to the whole liver, is emphasised.

Changes in T-cell count in patients undergoing radiotherapy. With particular reference to preoperative irradiation for gastric carcinoma

Energy Technology Data Exchange (ETDEWEB)

Makino, K; Sato, S [Tokyo Medical Coll. (Japan)

1980-01-01

To know changes in immunological competence of T-cells induced by radiotherapy, T-cells in peripheral blood of patients who underwent radiotherapy were observed before, during, and 6 months after the irradiation. The subjects were 69 patients having malignant tumors including 20 with gastric cancer, 15 with breast cancer, and 9 with colon cancer. 200 rad of an exposure dose was irradiated for successive 5 to 6 days. A total of exposure doses ranged from 2,000 to 10,000 rad. T-cell count decreased markedly until exposure doses reached 3,000 rad, but its decrease was mild after exposure doses were over 3,000 rad. T-cell count decreased slightly in patients whose head and neck were irradiated, but it decreased markedly in patients whose thorax and abdomen were irradiated. Therefore, it was thought that there was a relationship between exposed sites and the decrease in T-cell count. T-cell count decreased markedly when irradiation field was wide. The smaller exposure doses were, the earlier the recovery of T-cell were. T-cells irradiated with over 7,000 rad did not recover within 6 months after the irradiation. The recovery of T-cells in patients with gastric cancer who did not undergo gastrectomy was markedly worse than that in patients who had gastrectomy. Patterns of changes in T-cell count were divided into 4 (ascending curve, U-type curve, flat curve, and descending curve), and prognosis of patients were discussed. There was a clear difference in prognosis of patients among four patterns.

Cellular radiation effects and hyperthermia cell cycle kinetics of radiation sensitive mutants of saccharomyces cerevisiae after x-irradiation and hyperthermia

International Nuclear Information System (INIS)

Fingerhut, R.; Kiefer, J.; Otto, F.

1983-01-01

Radiosensitive mutants rad2, rad9, and rad51 of Saccharomyces cerevisiae were X-irradiated with 120 Gy or 60 Gy, heated at 50 0 C for 30 min or treated with a combination of both and incubated in nutrient medium at 30 0 C. Cell number, percentage of budding cells, and cell cycle progression were determined in 45-min intervals. Cell cycle kinetics were investigated by flow cytofluorometry. Hyperthermia leads mainly to a lengthening of G1, whereas X-rays arrest cells of the rad2 and rad9 mutant in G2 and the rad51 - mutant additionaly in a state with DNA contents above G2. Cell division dealy is influenced by oxygen in all strains but to a lesser extent in the rad2 mutant. The effect of the combined treatment appears to be merely additive in the rad2 and rad9 mutant while the rad51 mutant is sensitized to X-irradiation by hyperthermia. No selective action of hyperthermia on hypoxic cells was found. (orig.)

Survival patterns and hemopathological responses of dogs under continuous gamma irradiation

International Nuclear Information System (INIS)

Seed, T.M.; Fritz, T.E.; Tolle, D.V.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.; Kaspar, L.V.; Cullen, S.M.; Carnes, B.A.

1983-01-01

Survival curves were constructed and analyzed relative to contributing hematopathological responses for groups of beagles exposed continuously for duration of life to low daily doses of whole body 60 Co gamma irradiation (27.3 rads/day to 4 rads/day). The survival curves versus time were progressively displaced toward longer survival as rates of exposure were reduced from the relatively high dose rate of 27.3 rads/day to the low dose rate of 4.0 rads/day. Average survival times increased from 57 days at 27.3 rads/day to 1830 days at 4.0 rads/day, representing fractional increased life-spans from 1.5% to 50.8%, respectively. Survival curves versus total dose were markedly displaced along the cumulative radiation dose axis at the extreme dose rates (i.e., 27.3 and 4.0 rads/day), but not at the intermediate dose rates (i.e., 13.4 and 7.9 rads/day) in which the upper linear portions of the survival curves are superimposed. From these dose-dependent survival curves, LD 50 values for whole body gamma irradiation, delivered chronically at 27.3, 13.4, 7.9, and 4.0 rads per day were estimated to be 1442, 2124, 2039, and 7161 rads, respectively. Both time- and dose-dependent survival curves for the intermediate dose rates, in contrast to the extreme dose rates, exhibited pronounced transitions in the lethality rate below the 50% survival level. These lethality rate transitions occurred at approx. 2500 rads of accumulated dose and were attributed to a shift in the spectrum of developing hematopathologies: namely, from a predominance of the acutely ablative radiation-induced lymphohematopoietic syndromes (i.e., septicemias and aplastic anemias) to a predominance of the late arising hematopoietic neoplasias (myelogenous leukemia and related myeloproliferative disorders)

Sterilization of boll weevil pupae with fractionated doses of gamma irradiation

International Nuclear Information System (INIS)

Haynes, J.W.; Mitlin, N.; Davich, T.B.; Dawson, J.R.; McGovern, W.L.; McKibben, G.H.

1977-01-01

Fractionated doses of 6,250-8,000 rads of gamma irradiation administered to pupae of the boll weevil, Anthonomus grandis Boh., sexually sterilized both sexes. Mortality of males thus treated with 6,250 and 8,000 rads via fractionation was 14% and 27% respectively, by 5 days posttreatment compared with 46% mortality when an equivalent acute dose was administered to newly emerged adults. Pheromone production of males irradiated at 6,250 rads was one-third that of the control for the first 4 days, but equal that of the control during 5-11 days posttreatment. This procedure lends itself to the large-scale sterilization of weevils needed in an eradication program. This technique is applicable to other insects that are highly susceptible to acute doses

Relationship between X-ray irradiation and chromosomal damage in bone marrow tissue of mice

International Nuclear Information System (INIS)

Chaubey, R.C.; George, K.P.; Sundaram, K.

1976-01-01

X-ray induced chromosomal damage in bone-marrow tissue of male mice was studied using micronucleus technique. Dose response relationship was evaluated. Male Swiss mice received whole body x-ray irradiation at different doses from 25-1000 rads. Animals were sacrificed at the end of 24 hours, bone-marrow smears were made and stained in May-Grunwald-Giemsa. The preparatians were scored for the following types of aberrations: micronuclei in young erythocytes-polychromatic cells and in the mature erythrocytes-normechromatic cells. A dose dependent increase in the frequency of micronuclei in polychromatic cells up to a dose of 100 rads was observed. In addition the effect of post-irradiation duration on the frequency of micronuclei in polychromatic and normochromatic cells were studied. Male Swiss mice were exposed to 200 rads x-rays and were then sacrificed at different time intervals after irradiation and bone-marrow preparations were made and scored. Maximum polychromatic cells with micronuclei were observed in 24 hours post-irradiated animals, thereafter a decrease in the frequency of polychromatic cells with micronuclei was observed in 40 hours post irradiated animals. (author

Delayed match-to-sample early performance decrement in monkeys after 60Co irradiation

International Nuclear Information System (INIS)

Bruner, A.; Bogo, V.; Jones, R.K.

1975-01-01

Sixteen monkeys were trained on a delayed match-to-sample task (DMTS) based on shock avoidance and irradiated with single, whole-body exposures of from 396 to 2000 rad 60 Co (midbody dose) at between 163 and 233 rad/min. Pre- to post-irradiation performance changes were assessed using a penalty-scaling measure which differentially weighted incorrect responses, response omissions, and error-omission sequences. Thirteen of the animals displayed early performance decrement, including five incapacitations, at lower doses (less than 1000 rad) than heretofore found effective. This was considered a function of task complexity, measurement sensitivity, and gamma effectiveness. The minimum effective midbody dose for inducing decrement using the DMTS task was estimated to be on the order of 500 rad. The nature of early, transient performance decrement seems to reflect more of an inability to perform than an inability to perform correctly

Effects of prenatal X-irradiation on postnatal testicular development and function in the Wistar rat: development/teratology/behavior/radiation

International Nuclear Information System (INIS)

Jensh, R.P.; Brent, R.L.

1988-01-01

It is evident that significant permanent tissue hypoplasia can be produced following radiation exposure late in fetal development. Because two organs, brain and testes, are developmentally and functionally interrelated, it was of interest to determine whether fetal testicular hypoplasia was a primary or a secondary effect of fetal brain irradiation. Twenty-four pregnant Wistar strain rats were randomly assigned to one of four groups, and a laparotomy was performed on day 18 of gestation. The fetuses received sham irradiation, whole body irradiation, or only head/thorax or pelvic body irradiation at a dosage level of 1.5 Gy. Mothers were allowed to deliver and raise their offspring until postnatal day 30, when the offspring were weaned. At 60 days of age, 74 male offspring were allowed to mate with colony control females of similar age until successful insemination or until the males reached 90 days of age, when they were killed. Testes were weighed and processed for histologic examination. Direct radiation of testes, due to whole body or pelvic exposure, resulted in testicular growth retardation and significantly reduced spermatogenesis. Breeding activity of the males and the percent of positive inseminations were also slightly reduced. However, a significant percentage of male offspring receiving direct testicular radiation did produce offspring. Head/thorax-only irradiation did not adversely affect testicular growth or spermatogenesis. Therefore, the use of histologic analysis as the sole determinant of infertility may be misleading. This study indicates that testicular growth retardation and an increased infertility rate result from direct prenatal exposure of rat testes to X-radiation and are not necessarily mediated via X-irradiation effects on the central nervous system

Hematopoiesis on cellulose ester membranes (CEM). X. Effects of in vitro irradiation of stromal cells prior to application on CEM

International Nuclear Information System (INIS)

Knospe, W.H.; Husseini, S.G.

1986-01-01

Cellulose ester membranes (CEM) were coated with stromal cells from murine bone or bone marrow irradiated in vitro with 1000, 2000, or 4000 rad and then implanted i.p. in CAF1 mice for periods of six and 12 months. CEM coated with stromal cells from bone showed excellent regeneration of bone and hematopoiesis after 1000 rad in vitro irradiation. After 2000 rad, hematopoietic and bone regeneration was reduced by about 50%, and after 4000 rad it was completely absent in CEM coated with stromal cells from bone. CEM coated with stromal cells from bone marrow showed no regeneration of hematopoiesis or bone after 1000, 2000, and 4000 rad in vitro irradiation and residence i.p. for six and 12 months. These results indicate that regeneration of the hematopoietic microenvironment is dependent upon living stromal cells. A difference in radiation sensitivity is demonstrated between stromal cells from bone and from bone marrow

Change in concentration of inorganic phosphate and phosphocreatine in the rat diaphragm under the influence of whole-body gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Mansour, M A; Gaber, M; Abdel-Fatah, K I

1987-01-01

The influence of irradiation on the concentration of creatine phosphate and inorganic phosphate in the diaphragm muscle were studied in rats exposed to 400 rad and 800 rad whole-body gamma radiation. The results showed that on the first day of post-exposure with 400 rad, the creatine phosphate concentration significantly increased, while the level significantly decreased on the third up to the fourteenth days of post exposure. In animals exposed to 800 rad, the diaphragm phosphocreatine showed a significant decrease on the first up to the ninth day post-irradiation as compared with the control group.

Change in concentration of inorganic phosphate and phosphocreatine in the rat diaphragm under the influence of whole-body gamma irradiation

International Nuclear Information System (INIS)

Mansour, M.A.; Gaber, M.; Abdel-Fatah, K.I.

1987-01-01

The influence of irradiation on the concentration of creatine phosphate and inorganic phosphate in the diaphragm muscle were studied in rats exposed to 400 rad and 800 rad whole-body gamma radiation. The results showed that on the first day of post-exposure with 400 rad, the creatine phosphate concentration significantly increased, while the level significantly decreased on the third up to the fourteenth days of post exposure. In animals exposed to 800 rad, the diaphragm phosphocreatine showed a significant decrease on the first up to the ninth day post-irradiation as compared with the control group

X-irradiation in the prevention of experimental post-traumatic vitreous proliferations

International Nuclear Information System (INIS)

Belkin, M.; Avni, I.; Kessler, E.; Hercberg, A.; Spierer, A.; Treister, G.

1983-01-01

The authors created double perforating injuries in both eyes of 22 rabbits. One eye of each animal was given a dose of 600 Rad x-irradiation 24 hours after the injury. The irradiated eyes developed significantly less intraocular proliferation than the non-irradiated eyes. (author)

Rad and Mubad in Shahnameh of Ferdowsi

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z Delpazir

2011-09-01

However, the important points overlooked by explicators are the relationship between Rad and Mubad (Zoroastrian priest and the reason why these two words have co-occurred so frequently in Shahnameh, the most famous Persian national epic. It seems that Rad in Shahnameh, based on Avesta and Pahlavi texts, is often construed as Sadane or Dastoor that was a high position in ancient Iran’s religious hierarchy. Thus, Rads and Mubads were both considered members of religious communities. This study tries to investigate the role and position of Rads and Mubads and their relationship with one another, based on Shahnameh of Ferdowsi, in three chapters: The etymology of Rad Rad in Shahnameh The relationship between Rads and Mubads.

Cellular Dynamics of Rad51 and Rad54 in Response to Postreplicative Stress and DNA Damage in HeLa Cells.

Science.gov (United States)

Choi, Eui-Hwan; Yoon, Seobin; Hahn, Yoonsoo; Kim, Keun P

2017-02-01

Homologous recombination (HR) is necessary for maintenance of genomic integrity and prevention of various mutations in tumor suppressor genes and proto-oncogenes. Rad51 and Rad54 are key HR factors that cope with replication stress and DNA breaks in eukaryotes. Rad51 binds to single-stranded DNA (ssDNA) to form the presynaptic filament that promotes a homology search and DNA strand exchange, and Rad54 stimulates the strand-pairing function of Rad51. Here, we studied the molecular dynamics of Rad51 and Rad54 during the cell cycle of HeLa cells. These cells constitutively express Rad51 and Rad54 throughout the entire cell cycle, and the formation of foci immediately increased in response to various types of DNA damage and replication stress, except for caffeine, which suppressed the Rad51-dependent HR pathway. Depletion of Rad51 caused severe defects in response to postreplicative stress. Accordingly, HeLa cells were arrested at the G2-M transition although a small amount of Rad51 was steadily maintained in HeLa cells. Our results suggest that cell cycle progression and proliferation of HeLa cells can be tightly controlled by the abundance of HR proteins, which are essential for the rapid response to postreplicative stress and DNA damage stress.

Affinity purification and partial characterization of a yeast multiprotein complex for nucleotide excision repair using histidine-tagged Rad14 protein

International Nuclear Information System (INIS)

Rodriguez, K.; Talamantez, J.; Huang, W.; Reed, S.H.; Wang, Z.; Chen, L.; Feaver, W.J.; Friedberg, E.C.; Tomkinson, A.E.

1998-01-01

The nucleotide excision repair (NER) pathway of eukaryotes involves approximately 30 polypeptides. Reconstitution of this pathway with purified components is consistent with the sequential assembly of NER proteins at the DNA lesion. However, recent studies have suggested that NER proteins may be pre-assembled in a high molecular weight complex in the absence of DNA damage. To examine this model further, we have constructed a histidine-tagged version of the yeast DNA damage recognition protein Rad14. Affinity purification of this protein from yeast nuclear extracts resulted in the co-purification of Rad1, Rad7, Rad10, Rad16, Rad23, RPA, RPB1, and TFIIH proteins, whereas none of these proteins bound to the affinity resin in the absence of recombinant Rad14. Furthermore, many of the co-purifying proteins were present in approximately equimolar amounts. Co-elution of these proteins was also observed when the nuclear extract was fractionated by gel filtration, indicating that the NER proteins were associated in a complex with a molecular mass of >1000 kDa prior to affinity chromatography. The affinity purified NER complex catalyzed the incision of UV-irradiated DNA in an ATP-dependent reaction. We conclude that active high molecular weight complexes of NER proteins exist in undamaged yeast cells

Specific inhibition of Wee1 kinase and Rad51 recombinase: A strategy to enhance the sensitivity of leukemic T-cells to ionizing radiation-induced DNA double-strand breaks

International Nuclear Information System (INIS)

Havelek, Radim; Cmielova, Jana; Kralovec, Karel; Bruckova, Lenka; Bilkova, Zuzana; Fousova, Ivana; Sinkorova, Zuzana; Vavrova, Jirina; Rezacova, Martina

2014-01-01

Highlights: • Pre-treatment with the inhibitors increased the sensitivity of Jurkat cells to irradiation. • Combining both inhibitors together resulted in a G2 cell cycle arrest abrogation in Jurkat. • Jurkat cells pre-treated with inhibitors were positive for γH2AX foci 24 h upon irradiation. • Pre-treatment with Rad51 RI-1 had no effect on apoptosis induction in MOLT-4 cells. • When dosed together, the combination decreased MOLT-4 cell survival. - Abstract: Present-day oncology sees at least two-thirds of cancer patients receiving radiation therapy as a part of their anticancer treatment. The objectives of the current study were to investigate the effects of the small molecule inhibitors of Wee1 kinase II (681641) and Rad51 (RI-1) on cell cycle progression, DNA double-strand breaks repair and apoptosis following ionizing radiation exposure in human leukemic T-cells Jurkat and MOLT-4. Pre-treatment with the Wee1 681641 or Rad51 RI-1 inhibitor alone increased the sensitivity of Jurkat cells to irradiation, however combining both inhibitors together resulted in a further enhancement of apoptosis. Jurkat cells pre-treated with inhibitors were positive for γH2AX foci 24 h upon irradiation. MOLT-4 cells were less affected by inhibitors application prior to ionizing radiation exposure. Pre-treatment with Rad51 RI-1 had no effect on apoptosis induction; however Wee1 681641 increased ionizing radiation-induced cell death in MOLT-4 cells

Analysis of morbidity of children irradiated intrauterine as a result of the Chernobyl accident

International Nuclear Information System (INIS)

Sychik, S.I.; Stozharov, A.N.

1999-01-01

The purpose of the investigation was analysis of the influence of intrauterine irradiation of radioactive iodine on the structure and dynamics of prenatal irradiated children morbidity. It was examined children's group ( 10 years old aged ) irradiated in intrauterine status and having been lived constantly on polluted by radionuclide area of the Stolyn District of the Brest Region with contamination density of caesium 137 up to 15 Ci/km 2 . Control group were children aged 9 years old born after the accident and lived constantly in the same points that prenatal irradiated. The observation of morbidity since 1987 to 1995 years has shown that among prenatal irradiated children were more high parameters of general and primary morbidity in the structure of morbidity. It was established that thyroid gland participated in the forming of pathology of other organs and systems

Effects of pre-natal X-ray exposure on learning behaviour of mice

International Nuclear Information System (INIS)

Frank, P.; Faber, U.; Budny, T.

1983-01-01

The authors investigated whether prenatal X-raying affects the learning behaviour of mice. For this purpose they irradiated mice of strain C57BL/6Ffm with 130 r at different points of the fetal phase. Unirradiated mice served as controls. The animals underwent two learning test series of 14 days each teaching them optical signs. The results of the test series show a distinctly inferior learning ability in the animals exposed to pre-natal irradiation as compared to unirradiated controls. The extent of the reduction of the learning ability depends on the stage of the pregnancy at the time of X-ray exposure. The greatest difference as compared to non-irradiated mice occurred in the animals irradiated at the earliest stage (13th/14th day of pregnancy). The results of the other test groups (15th/16th and 17th/18th day of pregnancy) exhibited less distinct, but still significant differences to the controls. Exposure at the latest period (17th/18th day) coincided with the smallest difference. (orig./MG) [de

Structural and functional changes in the intenstine of irradiated and hypothermic irradiated rats : a scanning and transmission electron microscopic study

International Nuclear Information System (INIS)

Chaudhuri, S.; Chaudhuri, Swapna; Roy, Bijon

1982-01-01

Severe destructive changes in the intestine of rats following whole body exposure to gamma rays (832 rads) were observed by light microscope, scanning and transmission electron microscope studies. Hypothermia (15deg C rectal temperature) induced prior to irradiation protected the intestinal mucosa from destruction. A simultaneous study showed that glucose absorption decreased significantly in irradiated rats, whereas it was increased in hypothermic irradiated animals. (author)

Developmental effects of prenatal irradiation. Entwicklungsstoerungen nach praenataler Bestrahlung

Energy Technology Data Exchange (ETDEWEB)

Kriegel, H; Schmahl, W; Kistner, G; Stieve, F E

1982-01-01

This book is the result of a symposium which was organised jointly by the WHO and the department for nuclear biology of the Gesellschaft fuer Strahlen- und Umweltforschung (Society for Radiation- and Environmental Research) Neuherberg; the Institut fuer Strahlenhygiene (Institute for Radiation Hygiene) of the Federal Board of Health (Bundesgesundheitsamt), Neuherberg and the working group ''Radiation Biology'' in the ''Deutsche Roentgengesellschaft'' and took place in Neuherberg near Munich from the 26.-28. November 1980. Subjects dealt with the lectures were: Developmental disturbances caused by prenatal exposure to either external radiation or incorporation of radionuclides in the organism of the mother. Based on the prenatal radiation effects already known new experiences and new knowledge were reported on and show new consequences on peri- and postnatal development. Radiation effects of incorporated radionuclides include also questions of the biokinetics of radioactive substances at present the emphasis lies on diaplacental penetration. Questions of synergetic effects of radiation and diaplacentally penetrating chemical substances were discussed on the symposium as well. These subjects were also extensively dealt with in a panel discussion.

Types and three-dimensional distribution of neuronal ectopias in the brain of mice prenatally subjected to X-irradiation

Energy Technology Data Exchange (ETDEWEB)

Sun, Xue-Zhi; Takahashi, Sentaro; Kubota, Yoshihisa; Sato, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan); Cui, Chun; Fukui, Yoshihiro [Tokushima Univ. (Japan). School of Medicine; Inouye, Minoru [Shin Nippon Biomedical Lab., Ltd., Miyanoura, Kagoshima (Japan)

2002-03-01

The types and three-dimensional distribution of neocortical ectopias following prenatal exposure to X-irradiation were studied by a histological examination and computer reconstruction techniques. Pregnant ICR mice were subjected to X-irradiation at a dose of 1.5 Gy on embryonic day 13. The brains from 30-day-old mice were serially sectioned on the frontal plane at 15 {mu}m, stained with HE and observed with a microscope. The image data for the sections were input to a computer, and then reconstructed to three-dimensional brain structures using the Magellan 3.6 program. Sectional images were then drawn on a computer display at 240 {mu}m intervals, and the positions of the different types of neocortical ectopias were marked using color coding. Three types of neocortical ectopias were recognized in the irradiated brains. Neocortical Lay I ectopias were identified as small patches in the caudal occipital cortex, and were located more laterally in the neocortex in caudal sections than in the rostral sections. Periventricular ectopias were located more rostrally than Lay I ectopias, and were found from the most caudal extent of the presumed motor cortex to the most caudal extent of the lateral ventricle. Hippocampal ectopias appeared as continuous linear bands, and were frequently associated with the anterior parts of the periventricular ectopias. (author)

Value of irradiation of neck nodes metastases. Pt. 1. Treatment of palpable nodes

International Nuclear Information System (INIS)

Bujko, K.

1993-01-01

Medical records of 222 patients with neck nodes metastases from squamous cell carcinoma of supraglottic larynx, tonsil and base of tongue were analyzed. All cases were treated with definitive irradiation. 110 patients were treated with orthovoltage technique with total doses of 5000-6000 rads, 150-10 rads per fraction; 112 patients with Co-60 with total doses 6000-7000 rads, 180-230 rads per fraction. Local-regional control was achieved in 28% of cases. Failures in the neck nodes with primary tumor controlled, were recorded in 10% of patients. Failures in a primary tumor alone were observed in 26% of patients, in primary tumor and neck nodes in 36%. Radiocurability of primary tumor and involved neck nodes was similar. In cases with primary tumor controlled, the probability of eradication of neck nodes metastases is high, even in N3 stage patients. Residual neck nodes palpable 1 to 3 months after irradiation were unfavorable prognostic factor indicated 50% risk of neck recurrence. In patients with complete regression of primary and nodal disease, failure in neck nodes was recorded in 5% of cases. The role of surgery following irradiation in patients with cervical nodes metastases is discussed. (author)

Changes of natural killer activity following local 60Co irradiation in intracranial tumor-bearing mice

International Nuclear Information System (INIS)

Otsuka, Shin-ichi; Suda, Kinya; Yamashita, Junkoh; Takeuchi, Juji; Handa, Hajime

1982-01-01

Changes of natural killer activity (NK activity) by local 60 Co irradiation in intracranial tumor-bearing mice were studied by the method of 51 Cr release assay. Local irradiation was administered 10 days after intracranial transplantation of 203-Glioma which had been originally induced by 20-methylcholanthrene in C57BL mice. Irradiation suppressed the growth of tumor and prolonged the mean survival time. The 50% survival time of untreated mice was about 2.5 weeks but that of mice treated by a single dose of 1000 rad and 1500 rad of irradiation was about 4.5 weeks and 6.5 weeks respectively. NK activity of spleen cells in these mice was serially examined. NK activity was gradually increased in mice treated by local irradiation, while it was gradually decreased in mice without treatment. On the other hand, NK activity remained unchanged in non-tumor-bearing control mice. Mice treated with 1000 rad and 1500 rad of irradiation showed 44.0% and 47.6% of % specific 51 Cr release respectively 11 days after irradiation while normal mice showed 18.0%. The increased NK activity after local irradiation suggested that local irradiation might have enhanced the immunological defence mechanisms against the tumor in the tumor-bearing hosts. Some characteristics of effector cells in this assay system were examined. The cytotoxicity of spleen cells was removed by the treatment of anti-BAT serum and complement but was not removed by the treatment of anti-Thy-1.2 serum and complement. Since NK activity reflects the immunological resistance to tumors to some extent, it is felt important to clarify the significance of changes of NK activity in patients with brain tumors in relation to various treatments including surgery, radiotherapy, chemotherapy and immunotherapy in the next step. (author)

Recovery and radio-resistance in mice after external irradiation; Restauration et radio-resistance chez la souris apres irradiation externe

Energy Technology Data Exchange (ETDEWEB)

Le Guillou, S. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1965-07-01

The author presents a literature study concerning recovery from external irradiation and an analysis of experimental data (which appear to suggest the idea of a radio-resistance in animals), as well as the hypotheses put forward for explaining this phenomenon. The author then describes an experiment carried out on mice whose LD 50/30 days increased from 1005 to 1380 rads and for which it was shown that an increase occurs in the number of certain anti-bodies circulating after a low dose of {gamma} irradiation. (author) [French] L'auteur presente une etude bibliographique de la restauration apres irradiation externe et une analyse des donnees experimentales qui paraissent suggerer la notion de radioresistance chez les animaux ainsi que les hypotheses cherchant a expliquer ce phenomene. Il relate ensuite une experience realisee sur des souris dont la DL 50/30 jours est passee de 1005 a 1380 rads et dans laquelle est montree l'augmentation de certains anticorps circulant apres une faible dose d'irradiation gamma. (auteur)

Cytologic studies on irradiated gestric cancer cells

Energy Technology Data Exchange (ETDEWEB)

Isono, S; Takeda, T; Amakasu, H; Asakawa, H; Yamada, S [Miyagi Prefectural Adult Disease Center, Natori (Japan)

1981-06-01

The smears of the biopsy and resected specimens obtained from 74 cases of irradiated gastric cancer were cytologically analyzed for effects of irradiation. Irradiation increased the amount of both necrotic materials and neutrophils in the smears. Cancer cells were decreased in number almost in inverse proportion to irradiation dose. Clusters of cancer cells shrank in size and cells were less stratified after irradiation. Irradiated cytoplasms were swollen, vacuolated and stained abnormally. Irradiation with less than 3,000 rads gave rise to swelling of cytoplasms in almost all cases. Nuclei became enlarged, multiple, pyknotic and/or stained pale after irradiation. Nuclear swelling was more remarkable in cancer cells of differentiated adenocarcinomas.

The SRS2 suppressor of rad6 mutations of Saccharomyces cerevisiae acts by channeling DNA lesions into the RAD52 DNA repair pathway

International Nuclear Information System (INIS)

Schiestl, R.H.; Prakash, S.; Prakash, L.

1990-01-01

rad6 mutants of Saccharomyces cerevisiae are defective in the repair of damaged DNA, DNA damage induced mutagenesis, and sporulation. In order to identify genes that can substitute for RAD6 function, the authors have isolated genomic suppressors of the UV sensitivity of rad6 deletion (rad6Δ) mutations and show that they also suppress the γ-ray sensitivity but not the UV mutagenesis or sporulation defects of rad6. The suppressors show semidominance for suppression of UV sensitivity and dominance for suppression of γ-ray sensitivity. The six suppressor mutations they isolated are all alleles of the same locus and are also allelic to a previously described suppressor of the rad6-1 nonsense mutation, SRS2. They show that suppression of rad6Δ is dependent on the RAD52 recombinational repair pathway since suppression is not observed in the rad6Δ SRS2 strain containing an additional mutation in either the RAD51, RAD52, RAD54, RAD55 or RAD57 genes. Possible mechanisms by which SRS2 may channel unrepaired DNA lesions into the RAD52 DNA repair pathway are discussed

Effect of X-irradiation on fecundity, fertility and longevity of the red cotton bug Dysdercus koenigii Fabr

International Nuclear Information System (INIS)

Srivastava, K.P.; Deshpande, D.J.

1983-01-01

X-irradiation of the sexes affects reproduction in D. koenigii differently. Irradiation of the male has no effect on the fecundity of the female but that of the female affects it adversely. Fertility shows fluctuations at lower doses and a linear decline at higher ones irrespective of the sex irradiated. But whereas complete sterility (infertility) sets in the female at 2000 rad, the male needs 4000 rad to induce the same in the female, which indicates a greater radiosensitivity of the former, longevity is unaffected by X-irradiation, indicating lack of correlation between sterility and longevity reported to exist in some insects. (author)

Aversive conditioning in prenatally gamma-irradiated rats

International Nuclear Information System (INIS)

Tamaki, Yoshitaka; Hoshino, Kiyoshi; Kameyama, Yoshiro

1987-01-01

To examine how intrauterine exposure to gamma rays would exert on four kinds of aversive conditioning, rat fetuses were irradiated with 0.27, 0.48, or 1.46 Gy at Day 15 post conception. When ordinary avoidance conditioning was given to the groups with 0.27 and 0.48 Gy, there was no significant difference between the irradiated groups and the control group in the rate of positive avoidance response. Nor was this different in the irradiated groups and the control group, when the rate of baseline response was examined in avoidance conditioning. In positive avoidance conditioning to two kinds of anticipatory electric stimuli, the acquisition of avoidance was significantly inferior in all irradiated groups to that in the control group. When giving succesive discrimination learning, the group with 1.46 Gy tended to have higher rate of positive avoidance response and remarkably lower rate of passive avoidance response than the control group. (Namekawa, K.)

Experimental studies on the late change of preoperative irradiation ( 60Co) following colonic anastomosis

International Nuclear Information System (INIS)

Ieda, Katsuyuki; Katsumi, Masaharu; Matsumoto, Kohichi

1982-01-01

We irradiated single dose of 1000 rad (equivalent to fractioned dose of 2000 - 2500 rad for the human) to the lower abdomen of four mongrel dogs. One week after irradiation, we operated on them and performed colonic transection using an auto-suture instrument. We investigated whether the preoperative irradiation would disturb the colonic anastomosis or not, in a long-term observation. All the dogs appeared to be suffered from slight radiation proctitis after irradiation. But their symptoms gradually subsided. Two of them lost an appetite gradually and died on the fifth and sixth month after operation. We examined them macroscopically and microscopically on the third, fifth, sixth and eighth month after operation, respectively. We could not find any gross radiation injuries on the anastomoses and the other organs. The mucosa and submucosa proved microsopically well healed. Muscle layers did not adhered layer to layer because of auto-suture stapler. We could not find inflammatory cell infiltration nor excessive fibrosis. Therefore, we speculate that preoperative irradiation of single dose of 1000 rad does not affect the wound healingF of the colonic anastomoses, neither bring about the late change. (author)

Effect of chromic γ-irradiation with small doses on candidiasis development in white rats

International Nuclear Information System (INIS)

Berchev, K.; Krushkov, Iv.

1976-01-01

Rats continuously exposed to 2 rads/day during eight months (cumulative dose of 400 rads) and nonirradiated rats were infected with a candida cells administered intravenously. All the irradiated animals died ten days after infection while only ten per cent of the control animals died for the same period of time. A morphological study has revealed candidiasis in the irradiated rats; changes, mainly in the kidneys, and formation of candidiasis granulomas have been detected in the control animals

Epithelial cell kinetics in mouse and rat skin irradiated with electrons

International Nuclear Information System (INIS)

McMaster-Schuyler, L.

1984-02-01

Experiments were performed to examine the kinetic responses of mouse and rat epidermal cells in vivo after single doses of ionizing radiation including responses of hair follicles at times after irradiation. The labeling indices in both species were reduced to 30 to 50% of control values immediately following irradiation at all the doses. In the rat, the labeling indices recovered and overshot control values within the first three days after 300 to 1200 rads. The mouse labeling indices continued to be suppressed for up to 10 days after 300 to 2400 rads. This indicated that rat G 1 phase epidermal cells recovered three times faster than those of the mouse with respect to the ability to maintain or increase control level cell proliferation after irradiation. After 1800 and 2400 rads, doses which produce skin ulceration, both species showed a reduction in their labeling indices for up to 7 days, indicating that a dose-dependent mechanism of recovery may be operable in the rat. 99 refs., 15 figs., 6 tabs

Coordination of Rad1-Rad10 interactions with Msh2-Msh3, Saw1 and RPA is essential for functional 3' non-homologous tail removal.

Science.gov (United States)

Eichmiller, Robin; Medina-Rivera, Melisa; DeSanto, Rachel; Minca, Eugen; Kim, Christopher; Holland, Cory; Seol, Ja-Hwan; Schmit, Megan; Oramus, Diane; Smith, Jessica; Gallardo, Ignacio F; Finkelstein, Ilya J; Lee, Sang Eun; Surtees, Jennifer A

2018-04-06

Double strand DNA break repair (DSBR) comprises multiple pathways. A subset of DSBR pathways, including single strand annealing, involve intermediates with 3' non-homologous tails that must be removed to complete repair. In Saccharomyces cerevisiae, Rad1-Rad10 is the structure-specific endonuclease that cleaves the tails in 3' non-homologous tail removal (3' NHTR). Rad1-Rad10 is also an essential component of the nucleotide excision repair (NER) pathway. In both cases, Rad1-Rad10 requires protein partners for recruitment to the relevant DNA intermediate. Msh2-Msh3 and Saw1 recruit Rad1-Rad10 in 3' NHTR; Rad14 recruits Rad1-Rad10 in NER. We created two rad1 separation-of-function alleles, rad1R203A,K205A and rad1R218A; both are defective in 3' NHTR but functional in NER. In vitro, rad1R203A,K205A was impaired at multiple steps in 3' NHTR. The rad1R218A in vivo phenotype resembles that of msh2- or msh3-deleted cells; recruitment of rad1R218A-Rad10 to recombination intermediates is defective. Interactions among rad1R218A-Rad10 and Msh2-Msh3 and Saw1 are altered and rad1R218A-Rad10 interactions with RPA are compromised. We propose a model in which Rad1-Rad10 is recruited and positioned at the recombination intermediate through interactions, between Saw1 and DNA, Rad1-Rad10 and Msh2-Msh3, Saw1 and Msh2-Msh3 and Rad1-Rad10 and RPA. When any of these interactions is altered, 3' NHTR is impaired.

Regulation of Rad51-Mediated Homologous Recombination by BRCA2, DSS1 and RAD52

DEFF Research Database (Denmark)

Rants, Louise Olthaver Juhl

Homologous recombination (HR) provides a mechanism to restore integrity and maintain stability of the genetic material. HR is a major pathway for repair of DNA double-strand breaks (DSB), recovery of broken replication forks and generation of meiotic crossovers. The defining step in HR is homolog......Homologous recombination (HR) provides a mechanism to restore integrity and maintain stability of the genetic material. HR is a major pathway for repair of DNA double-strand breaks (DSB), recovery of broken replication forks and generation of meiotic crossovers. The defining step in HR...... is homologous strand exchange directed by the RecA-related recombinase Rad51. BRCA2 participates in HR by mediating Rad51 homology-directed repair. Both BRCA2 and Rad51 are essential for HR, DNA repair, and the maintenance of genome stability. In the present study, we seek to understand the mechanism of BRCA2...... with RAD52-mediated repair at sites of CPT-induced DNA damage. The synthetic lethality approach using RAD52 small molecule inhibitors in brca-deficient cancers is a promising therapeutic strategy for cancer treatment....

Effect of BCNU combined with total body irradiation or cyclophosphamide on survival of dogs after autologous marrow grafts

International Nuclear Information System (INIS)

Paterson, A.H.G.; English, D.

1979-01-01

Dogs were treated with either: (1) 750 rad total body irradiation; (2) BCNU 2 or 4 mg/kg IV 48 hours prior to 750 rad total body irradiation; or (3) BCNU 4 mg/kg IV plus cyclophosphamide 30 mg/kg IV. Results showed that of 11 dogs who received 750 rad total body irradiation and did not receive cryopreserved autologous bone marrow cells, none survived, compared to an 88% survival (31 of 35 dogs) after 750 rad total body irradiation if the dogs received stored autologous bone marrow cells. However, when the dogs were treated with BCNU 2 or 4 mg/kg prior to 750 rad total body irradiation the survival rate, despite infusion of autologous bone marrow cells, dropped to 25% (3 of 12 dogs) for BCNU 2 mg/kg, and 17% (2 of 12 dogs) for BCNU 4 mg/kg. This effect did not seem to be due to direct serum inhibition of hemopoietic cell proliferation since serum obtained at various intervals after BCNU administrations failed to inhibit CFU growth in vitro. The dogs died from hemorrhage and infection; at autopsy there was hemorrhagic pneumonitis and intestinal ulcerations with petechial hemorrhages, suggesting that the combination of BCNU and total body irradiation may have synergistic toxicity on the canine gastro-intestinal tract. When BCNU was combined with cyclophosphamide, reversal of marrow toxicity occurred in 54% (6 of 11 dogs) with stored autologous bone marrow cells compared to no survival (0 of 8 dogs) with stored autologous bone marrow cells. Thus while autologous bone marrow grafts are useful for reversal of marrow toxicity due to many therapeutic protocols, such grafts alone may not provide protection against toxicity due to the combination of high dosage BCNU and total body irradiation

Stem-spermatogonial survival and incidence of reciprocal translocations in the γ-irradiated boar

International Nuclear Information System (INIS)

Erickson, B.H.; Martin, P.G.

1984-01-01

To assess the effects of γ-radiation on stem-cell survival and incidence of reciprocal translocations, boar testes were irradiated with 100, 200, or 400 rad. Stem-cell survival was markedly affected by 100 rad (51% of control) and reduced to 34% of control by 400 rad. Production of differentiating spermatogonia renewal was incomplete at 12 weeks. Incidence of translocations peaked at 200 rad and the number occurring at 100 and 400 rad was similar. Kinetics of porcine spermatogonial renewal differs considerably from those of the rodent and, relative to the rodent, this may account for the boar's higher sensitivity to stem-cell killing and lower sensitivity to translocation

Effects of chronic postnatal opioid receptor blockade by naltrexone upon proliferation capacity in the prenatally x-irradiated brain of the rat

International Nuclear Information System (INIS)

Schmahl, W.; Miaskowski, U.

1991-01-01

We recently reported that in rats prenatally x-irradiated on gestation day 14 with 1 Gy, postnatal chronic application of the opioid antagonist naltrexone (Nx) led to a remarkable growth spurt of the microencephalic brain. In the present study we present histological and autoradiographic results found in the subependymal layer (SEL) of the forebrain lateral ventricles. Nx led to an intermittent augmentation of the mitotic index of the x-irradiated brains within a postnatal observation period of 24 weeks. The most conspicuous finding was transient hyperplasia of the SEL at 4-6 weeks of age which occurred in close proximity to an intact ependymal lining. Districts of the lateral ventricles which were denuded from ependyme and where the rest of the ependymal layer (EL) was dislocated peripherally showed upon Nx treatment a long-lasting SEL hyperplasia with a tendency towards dysplasia. These results revealed that repair proliferation of embryotoxic x-irradiation is normally under strong control by the opioid system. If that system, which exerts a suppressing effect upon glial growth, is blocked by Nx, prominent hyperplastic reactions occur which may be useful for repairing the lesion pattern

Effects of chronic postnatal opioid receptor blockade by naltrexone upon proliferation capacity in the prenatally x-irradiated brain of the rat

Energy Technology Data Exchange (ETDEWEB)

Schmahl, W.; Miaskowski, U. (Department of Pathology, Gesellschaft fuer Strahlen-und Umweltforschung mbh Muechen, Neuherberg (West Germany))

1991-01-01

We recently reported that in rats prenatally x-irradiated on gestation day 14 with 1 Gy, postnatal chronic application of the opioid antagonist naltrexone (Nx) led to a remarkable growth spurt of the microencephalic brain. In the present study we present histological and autoradiographic results found in the subependymal layer (SEL) of the forebrain lateral ventricles. Nx led to an intermittent augmentation of the mitotic index of the x-irradiated brains within a postnatal observation period of 24 weeks. The most conspicuous finding was transient hyperplasia of the SEL at 4-6 weeks of age which occurred in close proximity to an intact ependymal lining. Districts of the lateral ventricles which were denuded from ependyme and where the rest of the ependymal layer (EL) was dislocated peripherally showed upon Nx treatment a long-lasting SEL hyperplasia with a tendency towards dysplasia. These results revealed that repair proliferation of embryotoxic x-irradiation is normally under strong control by the opioid system. If that system, which exerts a suppressing effect upon glial growth, is blocked by Nx, prominent hyperplastic reactions occur which may be useful for repairing the lesion pattern.

Function of Rad51 paralogs in eukaryotic homologous recombinational repair

International Nuclear Information System (INIS)

Liu, N.; Skowronek, K.

2003-01-01

Full text: Homologous recombinational repair (HRR) is an important mechanism for maintaining genetic integrity and cancer prevention by accurately repair of DNA double strand breaks induced by environmental insults or occurred in DNA replication. A critical step in HRR is the polymerization of Rad51 on single stranded DNA to form nuclear protein filaments, the later conduct DNA strand paring and exchange between homologous strands. A number of proteins, including replication protein A (RPA), Rad52 and Rad51 paralogs, are suggested to modulate or facilitate the process of Rad51 filament formation. Five Rad51 paralogs, namely XRCC2, XRCC3, Rad51B, Rad51C and Rad51D have been identified in eucaryotic cells. These proteins show distant protein sequence identity to Rad51, to yeast Rad51 paralogs (Rad55 and Rad57) and to each other. Hamster or chicken mutants of Rad51 paralogs exhibit hypersensitivity to a variety of DNA damaging agents, especially cross-linking agents, and are defective in assembly of Rad51 onto HRR site after DNA damage. Recent data from our and other labs showed that Rad51 paralogs constitute two distinct complexes in cell extracts, one contains XRCC2, Rad51B, Rad51C and Rad51D, and the other contains Rad51C and XRCC3. Rad51C is involved in both complexes. Our results also showed that XRCC3-Rad51C complex interacts with Rad51 in vivo. Furthermore, overexpression of Rad52 can partially suppress the hypersensitivity of XRCC2 mutant irs1 to ionizing radiation and corrected the defects in Rad51 focus formation. These results suggest that XRCC2 and other Rad51 paralogs play a mediator function to Rad51 in the early stage of HRR

Prenatal effects of ancestral irradiation in inbred mice

International Nuclear Information System (INIS)

Sprackling, L.E.S.

1975-01-01

Mice from 13 inbred strains (S, Z, E, Bab, BaB, BrR, C, K, N, Q, G, CFW, CF1) received continuous cobalt 60 irradiation at low dose rates for varying numbers of consecutive generations. Some Bab and BaB mice had received continuous irradiation for from 24 to 31 generations and the other mice had up to six generations of continuous irradiation in their ancestry. At weaning, the mice were removed from the irradiation room and were mated within strains either to sibs or nonsibs. Ancestral and direct irradiation doses were calculated. The ancestral dose was the effective accumulated dose to the progeny of the mated mice. The direct dose was the amount of irradiation received by any mated female from her conception to her weaning. Each irradiated or control female was scored as fertile or sterile and in utero litter counts were made in pregnant females that were dissected past the tenth day of pregnancy; the sum of moles, dead embryos, and live embryos was the total in utero litter size. A ratio of the living embryos to the total number of embryos in utero was determined for each litter. An increase in ancestral or direct irradiation dose significantly decreased fertility in 11 of the 13 strains. The fertility curves for the pooled data were sigmoid in the area of the doses below those that caused complete sterility. Among the controls, there were significant strain differences in total litter size and in the ratio. Strain X--Y plots, with ancestral or direct doses plotted against total litter size or ratio, revealed the tendency for litter size to decrease as dose increased. The only trend shown for ratio was for the litters with ratios of 0.50 or less to appear more frequently among the irradiated mice. The few corpora lutea counts revealed nothing of significance. Generally, there was a definite trend toward fewer mice alive in utero among the irradiated mice

Pathologic changes in the lung following single and multi-fraction irradiation

International Nuclear Information System (INIS)

Travis, E.L.; Harley, R.A.; Fenn, J.O.; Klobukowski, C.J.; Hargrove, H.B.

1977-01-01

The limiting factor in the treatment of malignant disease with irradiation is the tolerance of normal tissue irradiated. In the present study the right lungs of rats were exposed to single doses of 2000 rad of x-radiation, to 10 x 200 rad, or to 5 x 400 rad. Animals from each group were sacrificed monthly for 6 months post exposure. Sections of lung were examined by light microscopy (LM) and by scanning or transmission electron microscopy (SEM and TEM). A focal exudative lesion was seen at 2 months after the single dose; it progressed to a proliferative and then reparative, fibrotic lesion by 6 months. Changes in epithelial lung components, particularly the presence of Type II pneumocytes, were found with both LM and TM. Vascular changes were less pronounced. A striking finding was the presence of mast cells in the alveolar walls. Neither of the multi-fraction schedules produced any of these changes, except hyperplasia of Type II cells following 5 x 400 rad. The possible implication of Type II and mast cells in radiation pneumonitis and fibrosis is discussed

Relationship of time--dose factors to tumor control and complications in the treatment of Cushing's disease by irradiation

International Nuclear Information System (INIS)

Aristizabal, S.; Caldwell, W.L.; Avila, J.; Mayer, E.G.

1977-01-01

The records of the Radiotherapy Division of the Radiology Department of Vanderbilt University Hospital were reviewed for the period 1952 to 1970. During those 19 years 45 patients with a well-documented diagnosis of Cushing's disease were treated initially by external irradiation of the pituitary. All of the patients were treated with megavoltage equipment using photons. When the results of irradiation are compared against total doses of radiation, it is evident that the control rate is unsatisfactory at doses less than 4000 rad and the maximum benefits of irradiation are evident in the 4500 to 5000 rad dose range. It is also clear that the complication rate increases as the dose exceeds 4800 rad. If the various treatment regimens of irradiation are converted to ''equivalent'' doses by the Nominal Standard Dose (NSD) or Time-Dose-Fractionation (TDF) methods, the relationship between ''dose'' and efficacy of therapy and complications is demonstrated. In order to reduce the possibility of treatment-related morbidity, the use of three or more small (4 x 4 cm) treatment portals or rotational techniques is recommended to a pituitary dose of 4600 to 5000 rad treating 5 days a week for 5 to 6 weeks

Radiation Effect on Body Weight and Hematological Changes of Hybrid Mice by Conventional Fraction, Large Abdominal Field Irradiation

International Nuclear Information System (INIS)

Lee, Sung Heon; Shin, Sei One; Kim, Myung Se

1985-01-01

Radiation effect on mammals, especially on hematologic changes, has been studied since discovery of x-ray. Various experimental animals were tried for radiobiological studies. 72 hybrid mice with conventional fraction (5X/week), large abdominal field (2 x 3cm, from symphysis pubic to xyphoid process) were used. Body weight was declined gradually by increasing irradiation doses, nadir was about 29.7% in male ; 30.4% in female at 6000 rad irradiation group. Hemoglobin value was nearly normal throughout entire treatment. Significant dropping of WBC count was noted to 40-50% of pretreatment values by only 1000 rad irradiation. Change of differential count was interesting; lymphocyte proportion showed gradual reduction, instead of gradual increasing of segmented neutrophil. Those proportion were reversed after 6000 rad irradiation. Urinary protein tests showed + - +++, showing no correlation with dosage. Application. of our study in clinical combination therapy (radiation + chemotherapy) was discussed

Study on the induction of thyroid tumors in rats using x irradiation in conjunction with a goitrogen

International Nuclear Information System (INIS)

Mahler, P.

1979-01-01

The influence of acute localized thyroid x irradiation and chronic goitrogen administration, separately or combined, on thyroid tumor formation in mature female rats was studied. In the first experiment, the radiation doses were 0, 80, 160, 320, or 640 rads, and the dosages of goitrogen were 0, 4, or 40 parts per million (ppM) of 1 methyl - 2 mercaptoimidazole (MMI). The incidence of rats with thyroid tumors in any treated group receiving 0 or 4 ppM MMI was not significantly greater than the incidence in the nontreated control group. However, the incidence in any of the 40 ppM MMI groups was significantly greater than that in the nontreated control group. At all the radiation doses other than 80 rads, the incidence was significantly greater than that in the non-irradiated group. No significant difference was seen in the incidence of rats with thyroid tumors on the basis of radiation dose. The incidence was so high at 80 rads that there was little margin for further increase by increasing the radiation dose. The mean serum thyroxine levels at 40 ppM MMI, 4 ppM MMI, and 0 ppM MMI were 1.9, 3.5, and 3.7 μg/100 ml, respectively. No markedeffect of thyroid irradiation on mean serum thyroxine levels was seen. In the second experiment, rats receiving 200 ppM MMI and thyroid irradiation were sacrificed at 7-1/2 months after treatment. Nearly all rats in the 0 and 80 rad groups and all in the 160, the 320, and the 640 rad groups had thyroid tumors. In the third experiment, serum T 4 levels were measured in treated rats. Rats receiving 640 rads + 0 ppM MMI showed a slight decrease in serum T 4 , while no change in serum T 4 levels was seen in rats receiving 0 rads + 4 ppM MMI or 640 rads + 4 ppM MMI. All rats receiving 40 ppM MMI, regardless of radiation dose, showed decreased serum T 4 levels

Effects of γ irradiation of hydra: elimination of interstitial cells from viable hydra

International Nuclear Information System (INIS)

Fradkin, M.; Kakis, H.; Campbell, R.D.

1978-01-01

Hydra attenuata and H. magnipapillata were γ-irradiated from a cesium source. All doses which had any observable effect (3000 rad and above) resulted in a reduction in the number of interstitial cells and of their differentiated product cells, or in the complete elimination of these cells. Interstitial cells were essentially completely eliminated within 5 days after irradiation doses above 5500 rad, and these hydra died. Irradiation doses of 4200 to 5500 rad resulted in a mixture of effects: some hydra recovered completely, some lost all interstitial cells and died, and some lost interstitial cells but could be propagated, as asexually reproducing clones, by hand feeding them. Hydra of some of these hand-fed clones entirely lacked interstitial cells and did not recover interstitial cells during subsequent culturing. Yet when these hydra were repopulated by interstitial cells from a normal hydra, they were restored to normal. Nerve cells became depleted more slowly than interstitial cells following irradiation, so animals can be obtained which possess nerve but no stem (interstitial) cells. The nerve cells and other derivatives of interstitial cells eventually disappear upon prolonged culture of the hydra. Thus γ irradiation can be used to eliminate interstitial cells from hydra, leaving viable polyps composed only of epithelial cells

The effect of low-dose total body irradiation on tumor control

International Nuclear Information System (INIS)

Sakamoto, Kiyohiko; Miyamoto, Miyako; Watabe, Nobuyuki.

1987-01-01

Total body irradiation (TBI) is considered to bring about an immunosuppressive effect on an organism, on the basis of data obtained from sublethal doses of TBI. However, there are no data on how low-dose TBI affects an organism. Over the last five years, we have been studying the effects of low-dose TBI on normal or tumor-bearing mice and the immunological background of these effects. In experimental studies, an increase in the TD50 value (the number of cells required for a tumor incidence of 50 %) in mice exposed to 10 rad was recognized and showed a remarkable increase at 6 hours to 15 hours after irradiation. TBI of 10 rad also showed an enhancement effect on tumor cell killing when given 12 hours before local tumor irradiation. In order to clarify the mechanism of this kind of effect, some immunological studies were performed using several immunological procedures, and the results suggested that 10 rad of TBI caused increasing tumor immunity in irradiated mice. Clinical trials in some patients with advanced tumors are now being undertaken on the basis of these experimental data, and the effect of TBI on tumor control appears promising, although it is too early to draw conclusions. (author)

Gamma irradiation of isolated rat islets pretransplantation produces indefinite allograft survival in cyclosporine-treated recipients

International Nuclear Information System (INIS)

James, R.F.; Lake, S.P.; Chamberlain, J.; Thirdborough, S.; Bassett, P.D.; Mistry, N.; Bell, P.R.

1989-01-01

In this study we have examined the use of low-dose gamma-irradiation for the reduction of islet immunogenicity in the strong allogeneic combination of WAG rat islets transplanted into diabetic AUG recipients. First, we determined that gamma-irradiation reduced immunogenicity in vitro by use of a modified MLR with WAG islets as stimulators and AUG splenocytes as responders. We then determined the maximum dose of gamma-irradiation that could be used (250 rads) before islet function was affected. As 250 rads islet pretreatment alone was ineffective in prolonging allograft survival, we combined the pretreatment with a short course (days 0, 1, 2; 30 mg/kg) of cyclosporine. We found that CsA was only effective in significantly prolonging allograft survival when given subcutaneously in olive oil. The CsA treatment alone gave a significantly prolonged survival time for the islet allografts (median, 37 days vs. 6 days for controls), but when combined with the 250 rads islet pretreatment a synergistic effect was seen with 100% becoming long-term survivors (greater than 100 days). The long-term surviving AUG rats from both the CsA alone group and the CsA plus 250 rads pretreated islets group were challenged with WAG dendritic cells (DC). The islets from the 250 rads pretreated group were subsequently rejected (day 6) while the CsA alone group were not affected. The role of low dose gamma-irradiation when combined with CsA treatment of islet graft recipients in inducing specific unresponsiveness will be discussed

Gamma irradiation of isolated rat islets pretransplantation produces indefinite allograft survival in cyclosporine-treated recipients

Energy Technology Data Exchange (ETDEWEB)

James, R.F.; Lake, S.P.; Chamberlain, J.; Thirdborough, S.; Bassett, P.D.; Mistry, N.; Bell, P.R.

1989-06-01

In this study we have examined the use of low-dose gamma-irradiation for the reduction of islet immunogenicity in the strong allogeneic combination of WAG rat islets transplanted into diabetic AUG recipients. First, we determined that gamma-irradiation reduced immunogenicity in vitro by use of a modified MLR with WAG islets as stimulators and AUG splenocytes as responders. We then determined the maximum dose of gamma-irradiation that could be used (250 rads) before islet function was affected. As 250 rads islet pretreatment alone was ineffective in prolonging allograft survival, we combined the pretreatment with a short course (days 0, 1, 2; 30 mg/kg) of cyclosporine. We found that CsA was only effective in significantly prolonging allograft survival when given subcutaneously in olive oil. The CsA treatment alone gave a significantly prolonged survival time for the islet allografts (median, 37 days vs. 6 days for controls), but when combined with the 250 rads islet pretreatment a synergistic effect was seen with 100% becoming long-term survivors (greater than 100 days). The long-term surviving AUG rats from both the CsA alone group and the CsA plus 250 rads pretreated islets group were challenged with WAG dendritic cells (DC). The islets from the 250 rads pretreated group were subsequently rejected (day 6) while the CsA alone group were not affected. The role of low dose gamma-irradiation when combined with CsA treatment of islet graft recipients in inducing specific unresponsiveness will be discussed.

Degradation and annealing studies on gamma rays irradiated COTS PPD CISs at different dose rates

International Nuclear Information System (INIS)

Wang, Zujun; Ma, Yingwu; Liu, Jing; Xue, Yuan; He, Baoping; Yao, Zhibin; Huang, Shaoyan; Liu, Minbo; Sheng, Jiangkun

2016-01-01

The degradation and annealing studies on Colbalt-60 gamma-rays irradiated commercial-off-the-shelf (COTS) pinned photodiode (PPD) CMOS image sensors (CISs) at the various dose rates are presented. The irradiation experiments of COTS PPD CISs are carried out at 0.3, 3.0 and 30.0 rad(Si)/s. The COTS PPD CISs are manufactured using a standard 0.18-μm CMOS technology with four-transistor pixel PPD architecture. The behavior of the tested CISs shows a remarkable degradation after irradiation and differs in the dose rates. The dark current, dark signal non-uniformity (DSNU), random noise, saturation output, signal to noise ratio (SNR), and dynamic range (DR) versus the total ionizing dose (TID) at the various dose rates are investigated. The tendency of dark current, DSNU, and random noise increase and saturation output, SNR, and DR to decrease at 3.0 rad(Si)/s are far greater than those at 0.3 and 30.0 rad(Si)/s. The damage mechanisms caused by TID irradiation at the various dose rates are also analyzed. The annealing tests are carried out at room temperature with unbiased conditions after irradiation.

Degradation and annealing studies on gamma rays irradiated COTS PPD CISs at different dose rates

Science.gov (United States)

Wang, Zujun; Ma, Yingwu; Liu, Jing; Xue, Yuan; He, Baoping; Yao, Zhibin; Huang, Shaoyan; Liu, Minbo; Sheng, Jiangkun

2016-06-01

The degradation and annealing studies on Colbalt-60 gamma-rays irradiated commercial-off-the-shelf (COTS) pinned photodiode (PPD) CMOS image sensors (CISs) at the various dose rates are presented. The irradiation experiments of COTS PPD CISs are carried out at 0.3, 3.0 and 30.0 rad(Si)/s. The COTS PPD CISs are manufactured using a standard 0.18-μm CMOS technology with four-transistor pixel PPD architecture. The behavior of the tested CISs shows a remarkable degradation after irradiation and differs in the dose rates. The dark current, dark signal non-uniformity (DSNU), random noise, saturation output, signal to noise ratio (SNR), and dynamic range (DR) versus the total ionizing dose (TID) at the various dose rates are investigated. The tendency of dark current, DSNU, and random noise increase and saturation output, SNR, and DR to decrease at 3.0 rad(Si)/s are far greater than those at 0.3 and 30.0 rad(Si)/s. The damage mechanisms caused by TID irradiation at the various dose rates are also analyzed. The annealing tests are carried out at room temperature with unbiased conditions after irradiation.

Experience of the irradiation method under mixed gas (95% O2 plus 5% CO2) inhalation

International Nuclear Information System (INIS)

Ikeda, Michio; Tazaki, Eio

1978-01-01

The irradiation method under mixed gas of 95% O 2 plus CO 2 inhalation at one atomosphere was discussed to improve therapeutic results, in malignant tumors which are not greatly sensitive to irradiation. Randomized study was done in each attending institute, with common protocols. As a result, no positive effect was recognized in irradiation method under mixed gas inhalation with daily dose of 200 rad and 5 fractions per week, which is widely used clinically. But when irradiation dose was increased up to 500 to 600 rad per fraction, effect of the mixed gas was remarkable. But against this, observing for years, results in irradiation under mixed gas inhalation were not always related to the improvement of the long term survival. (author)

Irradiation tests of critical components for remote handling system in gamma radiation environment

International Nuclear Information System (INIS)

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi

1996-03-01

This report covers the gamma ray irradiation tests according to the Agreement of ITER R and D Task (T35) in 1994 and describes radiation hardness of the standard components for the ITER remote handling system which are categorized into the robotics (Subtask-1), the viewing system (Subtask-2) and the common components (Subtask-3). The gamma ray irradiation tests have been conducted using No.2 and No.3 cells at the cobalt building of Takasaki Establishment in JAERI. The radiation source is cobalt sixty (Co-60), and the maximum dose rate of No.2 and No.3 cells is about 1x10 6 R/h and 2x10 6 R/h, respectively. The environmental conditions of the irradiation tests are described below and all of components excepting electrical wires have been tested in the No.2 cell. [No.2 cell : Atmosphere and ambient temperature No.3 cell : Nitrogen gas and 250degC] As a whole, many of components have been irradiated up to the rated dose of around 1x10 10 rads and the following main results are obtained. The developed AC servo motor and periscope for radiation use have shown excellent durability with the radiation hardness tolerable for more than 10 9 rads. An electrical connector compatible with remote operation has also shown no degradation of electrical characteristics after the irradiation of 10 10 rads. As for polyimide insulated wires, the mechanical and electrical characteristics are not degradated after the irradiation of 10 9 rads and more radiation hardness can be expected than the anticipation. On the contrary, standard position sensors such as rotary encoder show extremely low radiation hardness and further efforts have to be made for improvements. (J.P.N.)

RadCat 2.0 User Guide.

Energy Technology Data Exchange (ETDEWEB)

Osborn, Douglas.; Weiner, Ruth F.; Mills, George Scott; Hamp, Steve C.; O' Donnell, Brandon, M.; Orcutt, David J.; Heames, Terence J.; Hinojosa, Daniel

2005-01-01

This document provides a detailed discussion and a guide for the use of the RadCat 2.0 Graphical User Interface input file generator for the RADTRAN 5.5 code. The differences between RadCat 2.0 and RadCat 1.0 can be attributed to the differences between RADTRAN 5 and RADTRAN 5.5 as well as clarification for some of the input parameters. 3

Botryllus schlosseri (Tunicata) whole colony irradiation: Do senescent zooid resorption and immunological resorption involve similar recognition events

International Nuclear Information System (INIS)

Rinkevich, B.; Weissman, I.L.

1990-01-01

The colonial tunicate Botryllus schlosseri undergoes cyclic blastogenesis where feeding zooids are senescened and resorbed and a new generation of zooids takes over the colony. When non-identical colonies come into direct contact, they either reject each other or fuse. Fusion is usually followed by the resorption of one of the partners in the chimera (immunological resorption). The striking morphological similarities between the two resorption phenomena suggest that both may involve tissue destruction following self-nonself recognition events. Here we attempt to modify these two events by whole colony gamma irradiation assays. Three sets of experiments were performed: (1) different doses of whole colony irradiation for determination of irradiation effects (110 colonies); (2) pairs of irradiated-nonirradiated isografts of clonal replicates for the potential of reconstruction of the irradiated partners (23 pairs); (3) chimeras of irradiated-nonirradiated partners for analysis of resorption hierarchy. Mortality increased with the irradiation dose. All colonies exposed to more than 5,000 rads died within 19 days, while no colony died below 2,000 rads. The average mortality periods, in days, for doses of 6,000-8,000, 5,000, and 2,500-4,000 rads were 14.4 +/- 3.1 (n = 24), 19.8 +/- 6.0 (n = 15), and 19.6 + 5.1 (n = 22), respectively. Younger colonies (3-6 months old) may survive radiation better than older ones (more than 13 months). Many morphological alterations were recorded in irradiated colonies: ampullar contraction and/or dilation, accumulation of pigment cells within ampullae, abnormal bleeding from blood vessels, sluggish blood circulation, necrotic zones, reduction in bud number, and irregularities in zooid and system structures. With doses of 3,000-4,000 rads and above, irradiation arrested the formation of new buds and interrupted normal takeover

Interspecific comparison of the effects of continuous ionizing radiation on the primitive mammalian stem germ cell

International Nuclear Information System (INIS)

Erickson, B.H.

1978-01-01

The response of the mammalian oocyte to radiation is characterized by wide interspecific differences, and results of preliminary assays suggest that this may be the case with the primitive stem germ cell. To test the validity of this observation and to define probable causes for the differences, prenatal mice, rats, and guinea pigs were irradiated continuously throughout gestation at rates of 1 and 3 rads per 23-hr day. Prenatal pigs were irradiated continuously for 108 days at a dose rate of 0.25 rad per 23-hr day. In all cases germ cells were enumerated in gonads excised either at birth or 6 days after birth. A dose rate of 0.25 rad/day reduced the germ-cell number in the male and female pig to 38 and 60% of control, respectively, and only 1 and 5% of the germ cells in the respective sexes survived a dose rate of 1 rad/day. Application of the single-hit multitarget model to all pig data yielded values for D 0 and n of 28 and 0.8, respectively, for the male and 27 and 3.2, respectively, for the female. Corresponding values for the male and female rat were 275 (D 0 ) and 0.3 (n) and 159 (D 0 ) and 0.8 (n), respectively. Both sexes of the pig were either sterilized or brought near sterility by a dose rate of 1 rad/day. In the case of the male rodent, however, this dose rate reduced germ-cell number to only 71% of control in the mouse, 50% of control in the rat, and 41% of control in the guinea pig. Ninety percent of the germ cells in the female rat survived a dose rate of 1 rad/day, as did 87% in the mouse and 71% in the guinea pig. When total dose was used as the basis of comparison, the pig remained the most sensitive species. Thus the differences among rodent species are not great when compared to the tremendous difference between the rodent and pig. When rodents are compared with pigs, the difference in the magnitude of the effect of continuous irradiation on the primitive stem cells of both sexes appears to be dependent on length of time at risk

Myeloproliferative disorders in patients with rheumatoid arthritis treated with total body irradiation

International Nuclear Information System (INIS)

Urowitz, M.B.; Rider, W.D.

1985-01-01

Four patients with refractory rheumatoid arthritis were treated with total body irradiation administered in two sittings, 300 to 400 rads to each half of the body. All four patients had taken antimetabolites prior to receiving total body irradiation, and two continued to use them after total body irradiation. Two patients had taken alkylating agents before, and one had used them after total body irradiation. All patients showed clinical improvement. However, in two patients myeloproliferative disorders developed: a myelodysplastic preleukemia at 40 months after total body irradiation in one and acute myelogenous leukemia at 25 months in the other. Total body irradiation differs from total nodal irradiation in the total dose of irradiation (300 to 400 rads versus 2,000 to 3,000), and in the duration of the therapy (two sittings versus treatment over several weeks to months). Furthermore, the patients in the total body irradiation study frequently used cytotoxic drugs before and/or after irradiation, whereas in one total nodal irradiation study, azathioprine (2 mg/kg per day or less) was permitted, but no other cytotoxic agents were allowed. Rheumatologists may therefore face a binding decision when deciding to treat a patient with rheumatoid arthritis with either a cytotoxic drug or irradiation

Dose-response relations for dicentric yields in G0 lymphocytes of man and crab-eating monkey following acute and chronic γ-irradiations

International Nuclear Information System (INIS)

Takahashi, E.; Hirai, M.; Tobari, I.; Nakai, S.A.

1979-01-01

A comparison has been made of dicentric yields in G 0 lymphocytes between man and crab-eating monkey, Macaca fascicularis, after acute and chronic γ-irradiations. With acute irradiation (49.6 rad/min) there was no significant difference between them, but for the chronic irradiation (17.1 rad/h) a significant difference was observed between the species. When the dose-response relations were fitted to the linear-quadratic model (Y = αD + βD 2 ), the species-difference observed for chronic irradiation was almost entirely due to change in the value of β. In addition, after chronic irradiation the β-value for monkey was almost negligible, but that for man was significant. Post-irradiation incubation experiment showed that cells with dicentrics were partly eliminated during the course of chronic irradiation, because there were appreciable reductions of dicentric yields (ca. 25% for both man and monkey at 400 rad) together with mitotic indices (ca. 30% and 60% for man and monkey, respectively, at 400 rad). Accordingly, it would be reasonable to postulate that G 0 repair for dicentrics other than selection mechanism must play a major role in the effects of low dose rate. It can be further suggested that G 0 -repair capacity for chromosal damages leading to dicentrics may be different among different primate species. (Auth.)

Quantitative characterization of pyrimidine dimer excision from UV-irradiated DNA (excision capacity) by cell-free extracts of the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Bekker, M.L.; Kaboev, O.K.; Akhmedov, A.T.; Luchkina, L.A.

1984-01-01

Cell-free extracts from wild-type yeast (RAD + ) and from rad mutants belonging to the RAD3 epistatic group (rad1-1, rad2-1, rad3-1, rad4-1) contain activities catalyzing the excision of pyrimidine dimers (PD) from purified ultraviolet-irradiated DNA which was not pre-treated with exogenous UV-endonuclease. The level of these activities in cell-free extracts from rad mutants did not differ from that in wild-type extract and was close to the in vivo excision capacity of the latter calculated from the LD 37 (about 10 4 PD per haploid genome). (Auth.)

FANCI-FANCD2 stabilizes the RAD51-DNA complex by binding RAD51 and protects the 5′-DNA end

Science.gov (United States)

Sato, Koichi; Shimomuki, Mayo; Katsuki, Yoko; Takahashi, Daisuke; Kobayashi, Wataru; Ishiai, Masamichi; Miyoshi, Hiroyuki; Takata, Minoru; Kurumizaka, Hitoshi

2016-01-01

The FANCI-FANCD2 (I-D) complex is considered to work with RAD51 to protect the damaged DNA in the stalled replication fork. However, the means by which this DNA protection is accomplished have remained elusive. In the present study, we found that the I-D complex directly binds to RAD51, and stabilizes the RAD51-DNA filament. Unexpectedly, the DNA binding activity of FANCI, but not FANCD2, is explicitly required for the I-D complex-mediated RAD51-DNA filament stabilization. The RAD51 filament stabilized by the I-D complex actually protects the DNA end from nucleolytic degradation by an FA-associated nuclease, FAN1. This DNA end protection is not observed with the RAD51 mutant from FANCR patient cells. These results clearly answer the currently enigmatic question of how RAD51 functions with the I-D complex to prevent genomic instability at the stalled replication fork. PMID:27694619

Ionising radiation dosimetry by measuring thermally excited currents (TEC) in irradiated highpolymers

International Nuclear Information System (INIS)

Shtol'ts, V.; Petermann, V.; Nigot, V.

1976-01-01

The first results are presented in measuring thermally excited currents (TEC) in 60 Co - gamma irradiated polyethylene and teflon. The design of measuring instruments is described. The maximum background currents in nonirradiated samples reached 10 -13 A. The TEC curves are presented which have obtained under irradiation up to 0.1-1000 rad followed by heating in the temperature range from 20 to 250 deg C. The curves exhibited maxima at about 90 deg C for polyethylene and about 200 deg C for teflon. The TEC dose range has been determined to be 0.1-1000 rad and 5-1000 rad for polyethylene and teflon, respectively. The fading at room temperature after 100 hrs has appeared to be 50% for polyethylene and 60% for teflon. The main merit of the technique is assumed to be the simplicity of the measuring instruments [ru

Studies of the effect of 0.4-Gy and 0.6-Gy prenatal X-irradiation on postnatal adult behavior in the Wistar rat.

Science.gov (United States)

Jensh, R P; Brent, R L; Vogel, W H

1987-02-01

Thirty-four pregnant Wistar rats were X-irradiated on the 9th or 17th day of gestation at a dosage level 0.4 Gy or 0.6 Gy or were sham-irradiated. All mothers were allowed to deliver their offspring, and litters were limited to a maximum of eight on day 2. On day 30, 224 offspring were weaned and raised until 60 days of age, at which time testing began. Each rat randomly received, in random order, three of the following six behavioral tests: Water T-maze, Conditioned Avoidance Response, Forelimb Hanging, Activity Wheel, Swimming, and Open Field. There were no statistically significant differences between the irradiated and control groups for maternal weight or weight gain or mean litter size, although the litter size of the 17th day 0.6-Gy group was slightly lower. Among offspring irradiated with 0.6 Gy on the 17th day, 3-day-old neonates' weights were significantly reduced. Offspring irradiated on the 17th day with 0.6 Gy exhibited higher Conditioned Avoidance Response 5th-day and retest avoidance scores than did the controls. There were also significant sex differences in responses within the irradiated and control groups for several tests, which were unrelated to radiation exposure. The results of this study indicate that low-level X-irradiation during the fetal period of rat gestation results in neonatal growth retardation and subtle behavioral alterations that may be manifested in adult life. Growth retardation may be the most sensitive indicator of subtle effects that result from low-level prenatal exposure to X-rays.

Studies of the effect of 0.4-Gy and 0.6-Gy prenatal X-irradiation on postnatal adult behavior in the Wistar rat

International Nuclear Information System (INIS)

Jensh, R.P.; Brent, R.L.; Vogel, W.H.

1987-01-01

Thirty-four pregnant Wistar rats were X-irradiated on the 9th or 17th day of gestation at a dosage level 0.4 Gy or 0.6 Gy or were sham-irradiated. All mothers were allowed to deliver their offspring, and litters were limited to a maximum of eight on day 2. On day 30, 224 offspring were weaned and raised until 60 days of age, at which time testing began. Each rat randomly received, in random order, three of the following six behavioral tests: Water T-maze, Conditioned Avoidance Response, Forelimb Hanging, Activity Wheel, Swimming, and Open Field. There were no statistically significant differences between the irradiated and control groups for maternal weight or weight gain or mean litter size, although the litter size of the 17th day 0.6-Gy group was slightly lower. Among offspring irradiated with 0.6 Gy on the 17th day, 3-day-old neonates' weights were significantly reduced. Offspring irradiated on the 17th day with 0.6 Gy exhibited higher Conditioned Avoidance Response 5th-day and retest avoidance scores than did the controls. There were also significant sex differences in responses within the irradiated and control groups for several tests, which were unrelated to radiation exposure. The results of this study indicate that low-level X-irradiation during the fetal period of rat gestation results in neonatal growth retardation and subtle behavioral alterations that may be manifested in adult life. Growth retardation may be the most sensitive indicator of subtle effects that result from low-level prenatal exposure to X-rays

Extrahepatic bile duct carcinoma treated by intraluminal irradiation with iridium-192 wire

International Nuclear Information System (INIS)

Ikeda, Hiro; Kuroda, Tomosumi; Uchida, Hideo

1980-01-01

A 57-year-old male with obstructive jaundice was diagnosed extrahepatic bile duct carcinoma at bifurcation by percutaneous transhepatic cholangiography (PTC). He was treated 3,300 rad of external irradiation and then intraluminal irradiation using the Iridium-192 wire by two times with the aid of PTC internal drainage, each was given by the dose of 1,600 rad at 5 mm inside the tumor from the PTC-tube. He had been well for about 1 year and then died because of ascites and cachexia. Autopsy revealed only microscopic tumor cells remaining around the common duct below the cystic junction. It was confirmed that intraluminal irradiation using the Iridium-192 wire was potentially curable and easily applicable to the bile duct carcinoma. (author)

Free radical production by high energy shock waves--comparison with ionizing irradiation.

Science.gov (United States)

Morgan, T R; Laudone, V P; Heston, W D; Zeitz, L; Fair, W R

1988-01-01

Fricke chemical dosimetry is used as an indirect measure of the free radical production of ionizing irradiation. We adapted the Fricke ferrous sulfate radiation dosimeter to examine the chemical effects of high energy shock waves. Significant free radical production was documented. The reaction was dose dependent, predictably increased by acoustic impedance, but curvilinear. A thousand shocks at 18 kilovolts induced the same free radical oxidation as 1100 rad cobalt-60 gamma ionizing irradiation, increasing to 2900 rad in the presence of an air-fluid zone of acoustic impedance. The biological effect of these free radicals was compared to that of cobalt-60 ionizing irradiation by measuring the affect on Chinese hamster cells by clonogenic assay. While cobalt-60 irradiation produced a marked decrease in clonogenic survivors, little effect was noted with high energy shock waves. This suggested that the chemical effects produced by shock waves were either absent or attenuated in the cells, or were inherently less toxic than those of ionizing irradiation.

Effects of irradiation and storage on granulocytes harvested by continuous-flow centrifugation

International Nuclear Information System (INIS)

Patrone, F.; Dallegri, F.; Brema, F.; Sacchetti, C.

1979-01-01

Five normal subjects were subjected to leukapheresis by continuous-flow-centrifugation (CFC) in the Aminco Celltrifuge. Granulocyte functional capacities were evaluated on the venous blood samples drawn before apheresis and on the cellrich plasma collected by CFC, immediately after collection and after short-term storage at 4degC with or without previous irradiation (1500 rad, 50 rad/min). The CFC technique has been shown to provide cells without functional damage. Irradiation did not appear to influence granulocyte function, as evaluated by in vitro studies. The data demonstrate that granulocytes maintain, even after irradiation, functional activities similar to those found immediately after collection for up to 24 hours of storage at 4degC and exhibit only a moderate loss of function after 48 h. Chemotaxis appears to be the most sensitive detector of cellular damage of stored granulocytes, either irradiated or non-irradiated; this technique may be the most useful for assessment of granulocyte function before transfusion. (author)

Rib necrosis after postoperative irradiation with 6MeV x-ray to breast cancer

Energy Technology Data Exchange (ETDEWEB)

Asakawa, H; Watarai, J; Otawa, H [Miyagi Prefectural Adult Disease Center, Natori (Japan)

1975-04-01

In order to examine quality of rays in radiation injury in the rib by high energy x-ray, radiation injury in the rib was roentgenologically followed up in the subjects that received postoperative irradiation only with 6 MeV x-ray to breast cancer. The subjects consisted of 79 patients with the age of 30 to 78 and were irradiated with 200 rads of 6 MeV x-ray 5 times a week delivered in 5 to 6 weeks postoperatively. Two fields were irradiated in a day and the total dose reached more than 5,000 rads. Roentgenologic follow up for more than 12 months revealed that rib necrosis occurred in 9 (11%) of 79 patients and that there was no relation to the age of patient. The necrosis was most likely to develop in the right second rib 10 to 23 months after the irradiation and the mean was 16 months. To the rib region where necrosis occurred, 1,880 to 2,230 ret were irradiated and the mean was 2,014 ret. There found no relation between the irradiation dose and occurrence of rib necrosis in the extent of 4,000 to 6,000 rads for tumor doses. Radiation injury in the lung was complicated in 8 (89%) of 9 patients with rib necrosis, indicating high incidence.

Sensitivity difference between anterior and posterior lobes of rat cerebellum to prenatal exposure to 2.5 Gy X-irradiation. A histological study

International Nuclear Information System (INIS)

Darmanto, W.; Hayasaka, Shizu; Takagishi, Yoshiko; Aolad, H.M.; Inouye, Minoru

1997-01-01

We investigated the histological differences in abnormality between anterior lobes (vermian lobules II, III and culmen IV, V) and posterior lobes (lobules IX, X) of the rat cerebellum following prenatal exposure to X-irradiation. Pregnant rats were exposed to 2.5 Gy X-irradiation at gestation day-21 (GD-21), and pups were sacrificed from birth through 15 days of age. Their cerebella were examined histologically and immunohistochemically for glial fibrillary acidic protein in Bergmann fibers. Extensive cell death was found in the external granular layer (EGL) of the cerebellum on the day of birth. In the anterior lobes, the number of cell deaths was higher than in the posterior lobes. During 5 days after birth, the recovery of EGL was earlier in the posterior lobes than in the anterior lobes. Seven days after birth, Bergmann fibers were more irregular in the anterior lobes than in the posterior lobes. The number of Purkinje cells in ectopic locations was higher in the anterior lobes than in the posterior lobes. The EGL and migrating Purkinje cells showed different responses to X-irradiation in the anterior than in the posterior lobes of the cerebellum. (author)

Therapeutic irradiation and brain injury

International Nuclear Information System (INIS)

Sheline, G.E.; Wara, W.M.; Smith, V.

1980-01-01

This is a review and reanalysis of the literature on adverse effects of therapeutic irradiation on the brain. Reactions have been grouped and considered according to time of appearance. The emphasis of the analysis is on delayed reactions, especially those that occur from a few months to several years after irradiation. All dose specifications were converted into equivalent megavoltage rads. The data were analyzed in terms of total dose, overall treatment time and number of treatment fractions. Also discussed were acute radiation reactions, early delayed radiation reactions, somnolence and leukoencephalopathy post-irradiation/chemotherapy and combined effects of radiation and chemotherapy

RadCon: A Radiological Consequences Model

International Nuclear Information System (INIS)

Crawford, J.; Domel, R.U.

2000-05-01

RadCon estimates the dose received by user selected groups in the population from an accidental release of radionuclides to the environment. The exposure pathways considered are external exposure from the cloud and ground and internal exposure from inhalation and ingestion of contaminated food. Atmospheric dispersion modelling is carried out externally to RadCon.Given a two dimensional time varying air and ground concentration of radioactive elements, RadCon allows the user to: view the air and ground concentration over the affected area, select optional parameters and calculate the dose to people,display the results to the user, and change the parameter values. RadCon offers two user interfaces: 1) the standard graphical user interface which is started using Java DoseApp at the command line, or by setting up a shortcut to this command (particularly when RadCon is installed on a PC) and 2) the text based interface used to generate information for the model inter-comparison exercise . This is initiated using Java BIOMASS at the command line, or an equivalent shortcut. The text based interface was developed for research purposes and is not generally available. Appendices A, B and C provide a summary of instructions on setting up RadCon. This will generally be carried out by the computer support personnel

TRL1 gene expression in tomato (Solanum lycopersicum) floral organs after γ-irradiation

International Nuclear Information System (INIS)

Bondarenco, V.S.; Barbacar, N.I.

2009-01-01

The article describes the expression patterns of a novel RAD16-like TRL1 (tomato RAD16-like 1) gene in the floral organs of tomato during anther meiosis and mature flower stages. The data on the induction of the TRL1 expression as a result of γ-irradiation is discussed. (authors)

Protective effect of zinc against lethality of the irradiated mice

International Nuclear Information System (INIS)

Matsubara, J.; Inada, T.; Machida, K.

1982-01-01

The effects of adding 1000 ppm Zn in the drinking water 10 days before gamma irradiation (562 - 1000 rad) of mice were studied. The mice which had received zinc had a lower mortality rate and a longer survival time compared to the controls. The LD 50 of gamma radiation was 690 rad in the control group and 770 rad in the zinc group. Zinc added to the culture medium of human melanoma cells did not shown any change in radiosensitivity; thus the radioprotective effect of zinc appears to work at the whole body level. (U.K.)

Functional roles for Rad9 in prostate cancer

International Nuclear Information System (INIS)

Lieberman, H.B.; Broustas, C.G.

2012-01-01

The goal of this work is to understand the mechanistic relationship between high levels of Rad9 protein and prostate cancer. The study is based on several findings suggesting a role for Rad9 in this disease. Rad9 has all the hallmark features of an oncogene or tumor suppressor. It regulates genomic stability, multiple cell cycle checkpoints, apoptosis and DNA repair. In addition, it can transactivate downstream target genes via direct interaction with promoter DNA sequences. We found Rad9 protein levels were very high in prostate cancer cell lines. Furthermore, we examined 52 primary normal prostate and 339 prostate cancer specimens for Rad9 protein by immunohistochemical staining. Statistical significance for Rad9 positive staining versus cancer, and stain intensity versus Stage were tested. We get a p-value of <0.001 when comparing percentage positive by cancer Stage, or stain intensity by cancer Stage. Based on these data, we sought to define the nature of the relationship between Rad9 and prostate cancer. We demonstrate that Rad9 acts as an oncogene in prostate cancer by playing a critical role in tumor formation in a mouse xenograph model. We also show that Rad9 is important for cellular phenotypes essential for metastasis, including tumor cell migration, invasion and resistance to programmed cell death after detachment from extracellular matrix. Therefore, Rad9 is critical for several aspects of prostate tumor progression, and could serve as a novel target for anti-cancer therapy

PI-RADS v2: Current standing and future outlook.

Science.gov (United States)

Smith, Clayton P; Türkbey, Barış

2018-05-01

The Prostate Imaging-Reporting and Data System (PI-RADS) was created in 2012 to establish standardization in prostate multiparametric magnetic resonance imaging (mpMRI) acquisition, interpretation, and reporting. In hopes of improving upon some of the PI-RADS v1 shortcomings, the PI-RADS Steering Committee released PI-RADS v2 in 2015. This paper reviews the accuracy, interobserver agreement, and clinical outcomes of PI-RADS v2 and comments on the limitations of the current literature. Overall, PI-RADS v2 shows improved sensitivity and similar specificity compared to PI-RADS v1. However, concerns exist regarding interobserver agreement and the heterogeneity of the study methodology.

Experimental studies of the reimplantation of irradiated lung in dogs

Energy Technology Data Exchange (ETDEWEB)

Kondo, T; Fujimura, S; Sohara, Y; Kawakami, M; Okaniwa, G [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis and Cancer

1978-02-01

In order to treat the patients with lung cancer who have impaired cardiopulmonary function, a new method is designed, which includes the following steps; 1) pneumonectomy, 2) resection of tumor-bearing lobe, 3) /sup 60/Co irradiation to the remaining lobe, and 4) orthotopic reimplantation of the irradiated lung. The purpose of present study is to clarify the feasibility to use this method clinically. Using adult mongreal dogs, left lung was excised, irradiated and reimplanted. Radiation was carried out from 2,000 rad to 4,000 rad. Viability and function of reimplanted lungs were evaluated by their survival time, serial chest x-ray films, sup(99m)Tc-MAA perfusion scanning, unilateral pulmonary artery occlusion test and histologic examinations. Of 17 animals, 12 survived postoperative period and following results were obtained; 1) no dogs developed pulmonary edema, 2) only one dog was considered to die from acute radiation pneumonitis, 3) serial perfusion scanning showed a gradual decrease in flow distribution to the transplanted lung, 4) the right pulmonary occlusion test done in the dog irradiated with 2,000 rad revealed well reserved pulmonary function 2 months after the operation, and 5) histologically, most irradiated lungs revealed so-called ''late reaction'' of lung fibrosis, but there was the case with nearly normal findings after 6 months from the operation. Although many reports concerning to the radiation pneumonitis are published, there have not been any such reports as the present study. From our experiment, it may be indicated that there is a feasibility to use this new method clinically.

Experimental study on active specific immunotherapy modified with irradiation

International Nuclear Information System (INIS)

Imanaka, Kazufumi; Ogawa, Yasuhiro; Gose, Kyuhei; Imajo, Yoshinari; Kumura, Shuji

1982-01-01

We have already reported that the effectiveness of active specific immunotherapy using irradiated tumor cells and infiltrating mononuclear cells which were separated from the topical tumor tissue 7 days after irradiation of 2,000 rad in experimental study. The present study was designed to investigate the effect of non-specific immunopotentiator PS-K combined with active specific immunotherapy. Female C3H/He mice aged 12 weeks were inoculated 4 x 10 6 MM 46 tumor cells in the right hind paws and received local electron irradiation with the dose of 3,000 rad on the 5th day after irradiation. Active specific immunotherapy was performed on the 12th day, and daily dose of 200 mg/kg of PS-K was injected intraperitoneally from the 6th day to the 10th day. The inhibition of the tumor growth and the elongation of survival period were noted in the group which received active specific immunotherapy combined with non-specific immunopotentiator, PS-K compared with the active specific immunotherapy alone. (author)

Synergism of X irradiation and radiographic contrast medium

Energy Technology Data Exchange (ETDEWEB)

Carr, D; Walker, A; Tannahill, A J; White, R G [Glasgow Western Infirmary (UK)

1981-10-01

The results indicate that rabbits which had received abdominal x irradiation (750 rad) two hours before RCM (/sup 125/I-labelled meglumine ioglycamate) administration retained a significantly larger amount of RCM in the kidney, liver, spleen and plasma compared with animals which had received RCM with no prior x irradiation. There was no significant difference between the group receiving RCM alone and the group receiving RCM 24 h post-irradiation. With two insignificant exceptions, endotoxin assays were negative.

Effect of gamma irradiation on the the quality of ginger

International Nuclear Information System (INIS)

Parvez, K.; Khawaja, M.A.; Salahuddin' Kausar, T.

1998-01-01

Ginger (Zingebar officinale) was irradiated with gamma rays (10 k and 100 k rad) and stored at room temperature in sand, in refrigerator and deep freezer. 10 k rad. dose was most appropriate because it kept the texture of ginger intact for a longer storage period without affecting its important food ingredients i.e. moisture, soluble, insoluble ash and proteins, total sugar, soluble and reducing sugar contents. (author)

Anti-lipopolysaccharide toxin therapy for whole body X-irradiation overdose

Energy Technology Data Exchange (ETDEWEB)

Gaffin, S.L.; Wells, M.; Jordan, J.P.

1985-09-01

Death in humans from ionising radiation overexposure in the 3-8 Gy (300-800 rad) range is in part due to the toxaemia caused by the entry of gram-negative bacteria and/or their lipopolysaccharide toxin (LPS) into the blood circulation through the walls of partially denuded gut. Anti-LPS hyperimmune equine plasma was evaluated for its ability to lower irradiation-induced lethality. Mice were irradiated with 6.3 Gy (630 rad) and six days later received equine Anti-LPS hyperimmune plasma, control plasma or saline. Mortalities in the three groups were 58%, 92% and 79% (p < 0.01) respectively. Thus Anti-LPS may prove useful as an adjunct to conventional therapy in treating radiation sickness.

Anti-lipopolysaccharide toxin therapy for whole body X-irradiation overdose

International Nuclear Information System (INIS)

Gaffin, S.L.; Wells, M.; Jordan, J.P.

1985-01-01

Death in humans from ionising radiation overexposure in the 3-8 Gy (300-800 rad) range is in part due to the toxaemia caused by the entry of gram-negative bacteria and/or their lipopolysaccharide toxin (LPS) into the blood circulation through the walls of partially denuded gut. Anti-LPS hyperimmune equine plasma was evaluated for its ability to lower irradiation-induced lethality. Mice were irradiated with 6.3 Gy (630 rad) and six days later received equine Anti-LPS hyperimmune plasma, control plasma or saline. Mortalities in the three groups were 58%, 92% and 79% (p<0.01) respectively. Thus Anti-LPS may prove useful as an adjunct to conventional therapy in treating radiation sickness. (author)

Environmental monitoring at the Lawrence Livermore Laboratory. 1977 annual report

International Nuclear Information System (INIS)

Silver, W.J.; Lindeken, C.L.; Wong, K.M.; Willes, E.H.; White, J.H.

1978-01-01

This research consists of two parts. In one part irradiation was used to determine the radiosensitivity of prenatal female germ cells. Mice were given 18 rads of 60 Co γ-radiation (l rad/min) at various times in utero. The effect of this treatment was measured by light microscopic enumeration of unilaminar follicles remaining in the ovary at 49 days after birth. Greatest sensitivity was seen for irradiation on day 11 post conception. However the germ cells at this period were not as sensitive as are dictyate oocytes of the juvenile mouse. The other part of this study involved γ-irradiation of 14-day-old female mice. Electron microscopy was used to examine the ultra-structural changes taking place in the dictyate oocyte as a response to the radiation. Among the observed changes were irregular nuclear shape, nuclear membrane swelling, chromatin clumping, increased numbers of lysosomes and enlarged lysosomal areas. The significance and degree of these changes are discussed

RadVel: The Radial Velocity Modeling Toolkit

Science.gov (United States)

Fulton, Benjamin J.; Petigura, Erik A.; Blunt, Sarah; Sinukoff, Evan

2018-04-01

RadVel is an open-source Python package for modeling Keplerian orbits in radial velocity (RV) timeseries. RadVel provides a convenient framework to fit RVs using maximum a posteriori optimization and to compute robust confidence intervals by sampling the posterior probability density via Markov Chain Monte Carlo (MCMC). RadVel allows users to float or fix parameters, impose priors, and perform Bayesian model comparison. We have implemented real-time MCMC convergence tests to ensure adequate sampling of the posterior. RadVel can output a number of publication-quality plots and tables. Users may interface with RadVel through a convenient command-line interface or directly from Python. The code is object-oriented and thus naturally extensible. We encourage contributions from the community. Documentation is available at http://radvel.readthedocs.io.

Effects of grafts of single anterior pituitary glands on the incidence and type of mammary neoplasm in neutron- or γ-irradiated Fischer female rats

International Nuclear Information System (INIS)

Clifton, K.H.; Douple, E.B.; Sridharan, B.N.

1976-01-01

Three batches comprised of 48 young adult Fischer female rats each were subjected to total-body irradiation with 50 rads modified fission neutrons, or were given 600 rads 137 Cs γ-rays, or served as unirradiated controls. On the day following exposure, one-half of each batch was grafted with a single anterior pituitary gland beneath the left kidney capsule. The animals were observed for mammary neoplasia and all those that died during the experiment were autopsied. The experiment was terminated 538 +- 13 days after irradiation when all neutron-irradiated, pituitary-grafted animals had one or more mammary tumors. Only 2 of the 23 untreated rats that survived until termination of the experiment developed mammary fibroadenomas, and none had mammary carcinomas. The incidence of fibroadenomas was increased, and a single carcinoma was found in unirradiated rats with pituitary grafts. Irradiation alone caused an increase in the incidence of mammary fibroadenomas and the appearance of carcinomas. Fibroadenomas were markedly increased by the addition of pituitary grafts to irradiation. Carcinoma incidence was less markedly affected. The neutron dose of 50 rads was slightly more effective in inducing mammary neoplasms than the 600-rad dose of γ-rays

Effects of preoperative irradiation on primary tracheal anastomosis

International Nuclear Information System (INIS)

Tsubota, N.; Simpson, W.J.; Van Nostrand, A.W.P.; Pearson, F.G.

1975-01-01

Preoperative radiotherapy was used in the management of selected patients with cancer of the lung or trachea who might subsequently require segmental resection of bronchus or trachea and reconstruction by primary anastomosis. This study was designed to determine the effects of varying dosages of preoperative irradiation on anastomotic healing. Two rings were resected from the cervical trachea of 20 dogs following irradiation with varying doses of cesium. There were no important adverse effects on healing of the trachea or adjacent organs in dogs receiving up to 3,500 rads. All dogs receiving a higher dose than this developed some anastomotic stenosis, which was severe in 6 of 8 animals. Similar adverse effects were observed in 2 patients managed by preoperative radiotherapy (4,000 rads in three weeks) and tracheal resection with primary anastomosis

Effects of preoperative irradiation on primary tracheal anastomosis

Energy Technology Data Exchange (ETDEWEB)

Tsubota, N.; Simpson, W.J.; Van Nostrand, A.W.P.; Pearson, F.G.

1975-08-01

Preoperative radiotherapy was used in the management of selected patients with cancer of the lung or trachea who might subsequently require segmental resection of bronchus or trachea and reconstruction by primary anastomosis. This study was designed to determine the effects of varying dosages of preoperative irradiation on anastomotic healing. Two rings were resected from the cervical trachea of 20 dogs following irradiation with varying doses of cesium. There were no important adverse effects on healing of the trachea or adjacent organs in dogs receiving up to 3,500 rads. All dogs receiving a higher dose than this developed some anastomotic stenosis, which was severe in 6 of 8 animals. Similar adverse effects were observed in 2 patients managed by preoperative radiotherapy (4,000 rads in three weeks) and tracheal resection with primary anastomosis.

Experimental study on an active specific immunotherapy modified with irradiation, 1

International Nuclear Information System (INIS)

Ogawa, Yasuhiro; Takashima, Hitoshi; Imanaka, Kazufumi

1982-01-01

Active specific immunotherapy using low-dose-irradiated tumor cells and activated mononuclear cells was studied on the transplanted MM 46 tumor of female C3H/He mice aged 12 weeks, after radiotherapy was performed. Local irradiation with the dose of 3,000 rads by high energy electron beam was performed on the fifth day after 5 x 10 6 tumor cells were inoculated in the right hind paws. Tumor cells and mononuclear cells were separated from the tumor tissue which was irradiated with the dose of 2,000 rads on the fifth day and were injected subcutaneously into the left hind paws of the tumor burden mice on the eleventh day. Anti-tumor effect was evaluated by the changes of the tumor volume and survival curves. Tumor growth was significantly inhibited in the group which received irradiation combined with active specific immunotherapy compared with the control group (p < 0.01). Survival rate was significantly higher in the group which received irradiation combined with active specific immunotherapy than the control group (p < 0.025). (author)

Long Term RadNet Quality Data

Data.gov (United States)

U.S. Environmental Protection Agency — This RadNet Quality Data Asset includes all data since initiation and when ERAMS was expanded to become RadNet, name changed to reflect new mission. This includes...

Influence of thorax irradiation on lactic dehydrogenase isoenzyme activity

International Nuclear Information System (INIS)

Valle, C.; Munnich, A.; Pasquier, C.

The right hemi-thorax of rats was irradiated with 1200 and 3000 rads ( 60 Co) and blood samples were taken sequentially. The five lactic dehydrogenase (LDH) isoenzymes which have proved to be useful as biochemical indicators of acute pulmonary injury in other experimental animals (dogs), were assayed, after irradiation, as a function of time and as a functon of dose. There was no significant change in LDH isoenzyme activities after lung irradiation in rats [fr

Prenatal exposition on ionizing radiations

International Nuclear Information System (INIS)

2001-01-01

The Sessions on Prenatal Exposition on Ionizing Radiations was organized by the Argentine Radioprotection Society, in Buenos Aires, between 8 and 9, November 2001. In this event, were presented papers on: biological effects of ionizing radiation; the radiation protection and the pregnant woman; embryo fetal development and its relationship with the responsiveness to teratogens; radioinduced delayed mental; neonatal irradiation: neurotoxicity and modulation of pharmacological response; pre implanted mouse embryos as a model of uranium toxicity studies; hereditary effects of the radiation and new advances from the UNSCEAR 2001; doses estimation in embryo

Influence of irradiation upon neonative tolerance state induced in rabbit

International Nuclear Information System (INIS)

Servant, P.; Marquer, C.

An attempt was made to determine the effect of whole-body irradiation on the establishment of a state of tolerance in new-born rabbits by the intraperitoneal injection of 1mg of human serum albumin. Simultaneous irradiation (doses of 200, 150, 100 rads) and antigen injections inhibited the establishment of this tolerance [fr

Skin dose and response for the head and neck in patients irradiated with x-ray for tinea capitis: implications for environmental radioactivity

International Nuclear Information System (INIS)

Harley, N.H.; Kolber, A.B.; Shore, R.E.; Albert, R.E.; Altman, S.M.; Pasternack, B.S.

1983-01-01

The dose delivered to the skin of the head and neck in patients treated with x-ray irradiation for childhood tinea capitis was reconstructed. This was possible by utilizing a phantom made from the skull of a seven year old child and irradiating it with the same technique and x-ray machine used in tinea capitis therapy two to four decades ago. Seventy-eight basal cell carcinomas (BCC) have appeared so far in 40 of 1727 irradiated white children and none in 500 irradiated black children. The dose distribution over the face and scalp is used to estimate the risk of BCC per person per rad. These results must be considered preliminary due to the relatively young age of the irradiated group (<50 years) at the present time. From the decreased risk per rad for the portion of the scalp that is hair covered, it appears that environmental ultraviolet radiation may play a key role in the expression of BCC. A cumulative hazard plot is utilized to tentatively extend the data to lifetime risk of 0.003 per rad with an upper limit of 0.006 per rad. Environmental radiation dose to the skin possibly account for 20% of observed BCC if this tentative risk estimate is valid

Winter wheat stimulation experiment with irradiation

International Nuclear Information System (INIS)

Bozo, J.

1979-01-01

With respect to the conclusions drawn from this research it is necessary to emphasize that the results relate to one year, and even the statistically proved positive results are insufficient to establish tendencies without considering the aggregated results of one year and other effects. Tha analysis of crop yield shows that a dose of 500 rad is insufficient to induce higher yield. A dose of 1500 rad gave a definite response, and it would be desirable to observe the effects of larger doses, too. The reduction in internal fusarium infection of the grain yield was striking when the seed had been exposed to a dose of 1500 rad. The internal fusarium infection of the grain is a very important factor for both human nutrition and animal feeding. The maximum irradiation dose provided reliable immunity against fusarium infection. (author)

RadGenomics project

Energy Technology Data Exchange (ETDEWEB)

Iwakawa, Mayumi; Imai, Takashi; Harada, Yoshinobu [National Inst. of Radiological Sciences, Chiba (Japan). Frontier Research Center] [and others

2002-06-01

Human health is determined by a complex interplay of factors, predominantly between genetic susceptibility, environmental conditions and aging. The ultimate aim of the RadGenomics (Radiation Genomics) project is to understand the implications of heterogeneity in responses to ionizing radiation arising from genetic variation between individuals in the human population. The rapid progression of the human genome sequencing and the recent development of new technologies in molecular genetics are providing us with new opportunities to understand the genetic basis of individual differences in susceptibility to natural and/or artificial environmental factors, including radiation exposure. The RadGenomics project will inevitably lead to improved protocols for personalized radiotherapy and reductions in the potential side effects of such treatment. The project will contribute to future research into the molecular mechanisms of radiation sensitivity in humans and will stimulate the development of new high-throughput technologies for a broader application of biological and medical sciences. The staff members are specialists in a variety of fields, including genome science, radiation biology, medical science, molecular biology, and informatics, and have joined the RadGenomics project from various universities, companies, and research institutes. The project started in April 2001. (author)

RadGenomics project

International Nuclear Information System (INIS)

Iwakawa, Mayumi; Imai, Takashi; Harada, Yoshinobu

2002-01-01

Human health is determined by a complex interplay of factors, predominantly between genetic susceptibility, environmental conditions and aging. The ultimate aim of the RadGenomics (Radiation Genomics) project is to understand the implications of heterogeneity in responses to ionizing radiation arising from genetic variation between individuals in the human population. The rapid progression of the human genome sequencing and the recent development of new technologies in molecular genetics are providing us with new opportunities to understand the genetic basis of individual differences in susceptibility to natural and/or artificial environmental factors, including radiation exposure. The RadGenomics project will inevitably lead to improved protocols for personalized radiotherapy and reductions in the potential side effects of such treatment. The project will contribute to future research into the molecular mechanisms of radiation sensitivity in humans and will stimulate the development of new high-throughput technologies for a broader application of biological and medical sciences. The staff members are specialists in a variety of fields, including genome science, radiation biology, medical science, molecular biology, and informatics, and have joined the RadGenomics project from various universities, companies, and research institutes. The project started in April 2001. (author)

Hybridization Capture Using RAD Probes (hyRAD, a New Tool for Performing Genomic Analyses on Collection Specimens.

Directory of Open Access Journals (Sweden)

Tomasz Suchan

Full Text Available In the recent years, many protocols aimed at reproducibly sequencing reduced-genome subsets in non-model organisms have been published. Among them, RAD-sequencing is one of the most widely used. It relies on digesting DNA with specific restriction enzymes and performing size selection on the resulting fragments. Despite its acknowledged utility, this method is of limited use with degraded DNA samples, such as those isolated from museum specimens, as these samples are less likely to harbor fragments long enough to comprise two restriction sites making possible ligation of the adapter sequences (in the case of double-digest RAD or performing size selection of the resulting fragments (in the case of single-digest RAD. Here, we address these limitations by presenting a novel method called hybridization RAD (hyRAD. In this approach, biotinylated RAD fragments, covering a random fraction of the genome, are used as baits for capturing homologous fragments from genomic shotgun sequencing libraries. This simple and cost-effective approach allows sequencing of orthologous loci even from highly degraded DNA samples, opening new avenues of research in the field of museum genomics. Not relying on the restriction site presence, it improves among-sample loci coverage. In a trial study, hyRAD allowed us to obtain a large set of orthologous loci from fresh and museum samples from a non-model butterfly species, with a high proportion of single nucleotide polymorphisms present in all eight analyzed specimens, including 58-year-old museum samples. The utility of the method was further validated using 49 museum and fresh samples of a Palearctic grasshopper species for which the spatial genetic structure was previously assessed using mtDNA amplicons. The application of the method is eventually discussed in a wider context. As it does not rely on the restriction site presence, it is therefore not sensitive to among-sample loci polymorphisms in the restriction sites

Reactions of the intracellular NADpool in the yeast S. cerevisiae after UV-C- or X-ray irradiation

International Nuclear Information System (INIS)

Winckler, K.; Herfurth, E.

1988-01-01

The reaction of the intracellular NADpool after irradiation of cells either with UV-C light or with X-rays was studied in four different strains of the yeast S. cerevisiae. We found neither in wildtype strains nor in radiation sensitive mutants remarkable changes in the NADpool within 2 h after irradiation. Preculture of cells in medium enriched with nicotinic acid, a precursor of NAD, influenced the intracellular NAD concentration only to a small extent in all strains, but enhanced the radiation resistance against UV-C significantly in one rad6 mutant strain. The uptake of NAD and NAC by all strains before and after irradiation with UV-C and X-ray was tested also. NAD generally is taken up by the cells to a very low extent before and after irradiation without irradiation-dose dependency. NAC is taken up by all strains before and after irradiation. Only the rad6 mutant exhibited an irradiation-dose dependent NAC-uptake after UV-C irradiation. (orig.)

A case of eosinophilia related to irradiation

International Nuclear Information System (INIS)

Miki, Kozo; Matsumura, Tomohiro; Morishita, Masaharu; Namba, Kazuyuki; Kinoshita, Fumio

1978-01-01

A case of marked eosinophilia following radiotherapy for a malignant tumor of the lower jaw was reported. The patient (62 years old, male) was diagnosed as having squamous cell carcinoma, and the received external irradiation of 60 Co (the total dose of 2600 rad/13 f) and the administration of bleomycin (BLM) of 90 mg/6 f. However, the tumor did not disappear completely, and it was extracted. A marked increase of eosinophils was recognized 30 days after the finish of irradiation, and the percentage of eosinophils reached 46%. Moreover, it reached 52% 6 days after that time, but it decreased rapidly by blood transfusion during and after the operation. The percentage of eosinophils after the operation showed a mild or moderate increase. 5 months after the first irradiation, external irradiation of 60 Co with the total dose of 3000 rad/15 f was performed together with the administration of 5-Fu and BudR because of the recurrence. One month after irradiation started again, the percentage of eosinophils increased again to 23%, and after that, a rapid increase was still recognized. The percentage of eosinophils decreased to a normal range after blood transfusion. Eosinophilia in this case was suggested to be caused by radiatiotherapy, because an increase of eosinophils was recognized a certain period after irradiation, allergic reactions by drugs were not recognized on the skin except oral mucosa, and there was no past history of allergic diseases. (Ueda, J.)

Development of rat telencephalic neurons after prenatal x-irradiation

International Nuclear Information System (INIS)

Norton, S.

1979-01-01

Telencephalic neurons of rats, irradiated at day 15 of gestation with 125 R, develop synaptic connections on dendrites during maturation which appear to be normal spines in Golgi-stained light microscope preparations. At six weeks of postnatal age both control and irradiated rats have spiny dendritic processes on cortical pyramidal cells and caudate Golgi type II neurons. However, when the rats are 6 months old the irradiated rats have more neurons with beaded dendritic processes that lack spines or neurons and are likely to be degenerating neurons. The apparently normal development of the neurons followed by degeneration in the irradiated rat has a parallel in previous reports of the delayed hyperactivity which develops in rats irradiated on the fifteenth gestational day

Studies on increasing fertility of distant hybrid by irradiation of androgametes of wheat

International Nuclear Information System (INIS)

Chen Yichun; Sun Guangzu; Zhang Yuexue

1994-01-01

Distant hybridization was carried out by using hexaploid triticale, Heizha 266, as female parent and 2 varieties of spring wheat, Longfumai 3 and Longfumai 5, as male parent which were irradiated by slow irradiation of living bodies with 60 Co gamma rays from 600 to 2400 rad before distant hybridization. Through the observation of pollen mother cells of first generation of distant hybrilization (M 1 ), it was found that the amount of bivalents at meiosis metaphase was 13.65 on average, and was 14.55 on maximum, which were close to theoretical value, but the corresponding amount of bivalents at the same stage produced by unirradiated pollen mother cells were 12.80, which were lower than theorectical value. Chromosome pairing was improved by irradiation. Average setting ratio of M 1 generation affected by irradiation was 52.85%, but the corresponding figure for F 1 generation affected by un-irradiation was 6.49%. It is obvious that irradiation treatment increases setting rate of M 1 hybrid generation. The optimum doses for irradiating androgametes are 1600 and 2400 rad, respectively. However, there are significant differences of irradiation sensibility between different varieties of wheat

The effects of ionizing radiation on the face fly, Musca autumnalis DeGeer, irradiated in nitrogen

International Nuclear Information System (INIS)

Mansour, M.Y.

1987-01-01

Six day old face fly pupae, one day before emergence, were irradiated in a nitrogenous atmosphere using gamma radiation from a cobalt 60 source. Six levels of gamma radiation were used: 0, 500, 1000, 1500, 2000 and 2500 rads. The effects of gamma radiation on eclosion, reproduction, and male longevity and competitiveness were determined. Female mating habits under laboratory conditions were also examined. Irradiation under anoxic conditions did not adversely affect adult eclosion, female fecundity or male competitiveness. Sterility in treated males and females increased as radiation dosage increased. A dose of 2500 rads reduced fertility of males to less than 1% and produced similar results in the females. Longevity of treated males was not affected by increasing radiation dose up to 2000 rads. However, males receiving 2500 rads died sooner than unirradiated males. Studies on the mating habit of the female face fly showed that most of the females mated only once; however, a few of them mated a second time

Effect of 680 rad whole-body irradiation of a human fetus, 27 years afterwards

International Nuclear Information System (INIS)

Kallinger, W.; Granninger, W.

1982-01-01

In 1953 a 38-year-old pregnant woman was given radiation treatment with Ra-226 due to a vaginal carcinoma. The radiation field was reproduced by means of a computer program. It was proved that the fetus was exposed to radiation doses of 50-2000 rad. Despite this high dose no abnormalities were found during clinical examination of the now 27-year-old man who has already fathered a healthy son. (orig.) [de

Mechanism of derivation of radioresistance in HeLa cell population after repeated x-irradiation

International Nuclear Information System (INIS)

Kubo, Kihei; Koiwai, Soichiro; Morita, Kazuo

1982-01-01

The Radioresistant strain (X-8-5) was obtained from HeLa-SC population X-irradiated repeatedly for five times with 800 rad. The mean lethal dose (D 0 ) was 196 rad for X-8-5 cells, while it was 166 rad for control HeLa-SC cells. The fraction of cells containing an unusually long acrocentric chromosome (LA 2) exclusively increased with increasing number of irradiation of HeLa-SC population. A clonal strain with LA 2 marker was isolated from X-8-5 population and named RC-355. Since the RC-355 cells were more resistant (D 0 = 220 rad)than parental X-8-5 cells (D 0 = 196 rad), it was suggested that the cells with LA 2 were responsible for the radioresistance of X-8-5 population. The RC-355 cells were further subjected to the analysis of Q-banded karyotypes and it was observed that 18 types of specific markers (rm 1-17 and LA 2) were included in RC-355 cells in addition to 12 types of markers observed in most of HeLa-SC cells. Since the analysis of Q-banded karyotypes of RC-355 cells showed that RC-355 specific markers were not produced by radiation-induced rearrangements of HeLa-SC chromosomes, because twelve kinds of HeLa-SC markers were presented in RC-355 cells without any change, it was concluded that a small number of cells with LA 2 marker were originally presented in the control population and the relative fraction of them occupied increased after irradiation. (author)

Radiation-induced cancer of the esophagus after postoperative irradiation for breast cancer

International Nuclear Information System (INIS)

Ito, Ichiro; Miyaishi, Kazuo; Mitsuhashi, Norio; Ito, Jun; Inoue, Tomio

1978-01-01

Two cases of radiation-induced cancer of the esophagus after postoperative irradiation for breast cancer were reported. Latent period of case 1 (cervical esophagus) was 12 years, and case 2 (middle thoracic esophagus) was 16 years. Radiographically the lesions were both serrated, and histologically, case 1 was ''poorly differentiated'' and case 2 was ''moderately differentiated'' squamous cell carcinoma. Histological types of basic breast cancer were both papillotubular carcinomas. Previous irradiation doses were 4180 rads for case 1 and 1860 rads for case 2. The esophageal cancers were remarkably improved by radiation therapy. It should be emphasized that radiation therapy is useful for the radiation-induced cancer of the esophagus. (author)

Structured reporting platform improves CAD-RADS assessment.

Science.gov (United States)

Szilveszter, Bálint; Kolossváry, Márton; Karády, Júlia; Jermendy, Ádám L; Károlyi, Mihály; Panajotu, Alexisz; Bagyura, Zsolt; Vecsey-Nagy, Milán; Cury, Ricardo C; Leipsic, Jonathon A; Merkely, Béla; Maurovich-Horvat, Pál

2017-11-01

Structured reporting in cardiac imaging is strongly encouraged to improve quality through consistency. The Coronary Artery Disease - Reporting and Data System (CAD-RADS) was recently introduced to facilitate interdisciplinary communication of coronary CT angiography (CTA) results. We aimed to assess the agreement between manual and automated CAD-RADS classification using a structured reporting platform. Five readers prospectively interpreted 500 coronary CT angiographies using a structured reporting platform that automatically calculates the CAD-RADS score based on stenosis and plaque parameters manually entered by the reader. In addition, all readers manually assessed CAD-RADS blinded to the automatically derived results, which was used as the reference standard. We evaluated factors influencing reader performance including CAD-RADS training, clinical load, time of the day and level of expertise. Total agreement between manual and automated classification was 80.2%. Agreement in stenosis categories was 86.7%, whereas the agreement in modifiers was 95.8% for "N", 96.8% for "S", 95.6% for "V" and 99.4% for "G". Agreement for V improved after CAD-RADS training (p = 0.047). Time of the day and clinical load did not influence reader performance (p > 0.05 both). Less experienced readers had a higher total agreement as compared to more experienced readers (87.0% vs 78.0%, respectively; p = 0.011). Even though automated CAD-RADS classification uses data filled in by the readers, it outperforms manual classification by preventing human errors. Structured reporting platforms with automated calculation of the CAD-RADS score might improve data quality and support standardization of clinical decision making. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Moving beam irradiation in combined therapy of cervix uteri cancer

Energy Technology Data Exchange (ETDEWEB)

Kim, O M; Zholkiver, K I

1976-07-01

Postoperative moving beam irradiation in a dose of 3900 to 365 rad was conducted in 98 patients with the I--II stages of cervix uteri cancer. Skin reactions to irradiation were absent, marked leukopenia developed in 4 patients. Of 39 patients followed up for more than 5 years 35 have lived without relapses and metastases.

A study on the fortuitons advantage of gamma irradiation in the prophylaxis of transmissible malaria by flood transfusion

International Nuclear Information System (INIS)

Braz, Lucia Maria Almeida; Amato Neto, Vicente; Carignani, Fabio Luis; Fernandes, Andreia Otaviano di Pietro; Hamerschlak, Nelson; Zuanella, Laura Santoro; Silva, Maria de Fatima dos Santos; Okumura, Massayuki

1998-01-01

This study was carried out to evaluate the fortuitons advantages of using gamma irradiation on the prophylaxis of transmissible malaria by flood transfusion, with mice as the experimental model. In the first step, when the infected blood with Plasmodium berghei was submitted to 2,500 rad and 5,000 rad, with or without metronidazol, there was no success, because the animals presented parasitaemia and died after inoculation of irradiated blood. However there was partial success in the second step, when the infected blood received 10,000 and 15,000 rad, and was inoculated in mice, which showed infection and presented a survival rate of 20% and 40%, respectively, with later negativation of blood infected by P. berghei. (author)

Postoperative irradiation of glaucoma filtering surgery

International Nuclear Information System (INIS)

Mano, Tomiya; Manabe, Reizo; Masaki, Norie; Ohashi, Yuichi; Umemoto, Masayo; Kinoshita, Shigeru; Yamamoto, Ryo; Hirose, Naomi.

1986-01-01

To inhibit the subcojunctival scarring after glaucoma filtering surgery, Sr-90 beta-irradiation of 10 Gy in 1 fraction or 20 Gy in 2 fractions has been tried in 12 eyes. Usual trabeculectomy followed by beta-irradiation was performed on 6 eyes. Of these, 3/6 eyes were meintained in normal range of IOP after irradiation. Furthermore, combined surgery of trabeculectomy, tenectomy and episcleral resection followed by beta-irradiation were performed on 6 eyes. Of these, 5/6 eyes were maintained in normal range of IOP. No complications was observed during 3 to 8 months of followup periods after treatment. Filtering surgery combined with postoperative beta-irradiation seems to inhibit the proliferation of subcon-junctival fibroblast and to control IOP. (1 Gy = 100 rad). (author)

Late vascular effects in irradiated mice brain. In relation to experimental radionecrosis

Energy Technology Data Exchange (ETDEWEB)

Yoshii, Y; Maki, Y [Tsukuba Univ., Sakura, Ibaraki (Japan); Phillips, T L

1982-03-01

The whole brains of mice were irradiated with 250 kVp X-ray at 120 rad min/sup -1/ (1.6 mm Cu HVL, TSD 50 cm) and a histological study was done. The dose range of X-irradiation was from 1300 to 2500 rads. i.e., 1300, 1500, 1750, 2000, and 2500 rads. In the microscopic examination, the mice were killed at the regular postirradiation intervals of between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. A histological examination was performed by a morphometric estimation of vascular lesion in which the degree of the damage to the arterial system was scored through whole serial brain sections. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectatic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large artery were observed. Incidence of the fibrinoid necrosis increased dose dependently between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 - 87 weeks and can be used to quantify the vessel injury and a fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis.

Taurine content of tissues of irradiated rats

International Nuclear Information System (INIS)

Akhalaya, M.Ya.; Bogatyrev, G.P.; Kudryashov, Yu.B.; Yartsev, E.I.

1976-01-01

The taurine content of tissues (liver, stomach, small intestine and spleen) of rats irradiated with doses of 700 and 450 rads has been studied. Phase changes have been found in the taurine content of radiosensitive tissues in the course of radiation injury development

Effect of hyperthermia on epithelial microneoplastic cell populations induced by irradiation of rat skin

International Nuclear Information System (INIS)

Gragtmans, N.J.; McGregor, J.F.

1983-01-01

Two groups of male rats of the Charles River CD stock received a dose of 1,600 rad beta-radiation (700 rad/min) on the skin of the dorsum. Two months later, the site of irradiation of one of the groups was treated with hyperthermia at 44 degrees C for 2.5 minutes. A third control group received only the hyperthermic treatment. Over 90% of the animals in the 2 irradiated groups developed skin tumors (benign and malignant epithelial) at the irradiated site. There was no significant difference between these 2 groups in incidence of animals with tumors, incidence of tumors, distribution of tumor types, or rate of tumor appearance. The incidence of animals with tumors in the control group was less than 4% at any time

Effect of ultra-low dose whole-body-irradiation on severe patients with myasthenia gravis

International Nuclear Information System (INIS)

Arimori, Shigeru; Koriyama, Kenji

1982-01-01

An ultra-low dose whole body irradiation therapy was given to 5 patients with intractable bulbar syndrome, in a dose of 10 rad/fraction, 2 times a week for 5 weeks, with a total of 100 rad; and effects of this therapy on their clinical symptoms and immunological ability were discussed. In 3 of them, bulbar syndrome was improved, and the other one, the first irradiation was effective. The peripheral leukocyte count and lymphocyte count became lowest immediately after completion of the irradiation, and returned to the normal level within 1 to 2 months. The function of T-cells, especially suppressive T-cells, was recovered; and decrease in B-cells, resulted in a decrease in the AChR antibody titer. (Ueda, J.)

Effect of ultra-low dose whole-body-irradiation on patients with severe myasthenia gravis

Energy Technology Data Exchange (ETDEWEB)

Arimori, Shigeru; Koriyama, Kenji (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

1982-12-01

An ultra-low dose whole body irradiation therapy was given to 5 patients with intractable bulbar syndrome, in a dose of 10 rad/fraction, 2 times a week for 5 weeks, with a total of 100 rad; and effects of this therapy on their clinical symptoms and immunological ability were discussed. In 3 of them, bulbar syndrome was improved, and the other one, the first irradiation was effective. The peripheral leukocyte count and lymphocyte count became lowest immediately after completion of the irradiation, and returned to the normal level within 1 to 2 months. The function of T-cells, especially suppressive T-cells, was recovered; and decrease in B-cells, resulted in a decrease in the AChR antibody titer.

Cobalt-60 total body irradiation dosimetry at 220 cm source-axis distance

International Nuclear Information System (INIS)

Glasgow, G.P.; Mill, W.B.

1980-01-01

Adults with acute leukemia are treated with cyclophosphamide and total body irradiation (TBI) followed by autologous marrow transplants. For TBI, patients seated in a stand angled 45 0 above the floor are treated for about 2 hours at 220 cm source-axis distance (SAD) with sequential right and left lateral 87 cm x 87 cm fields to a 900 rad mid-pelvic dose at about 8 rad/min using a 5000 Ci cobalt unit. Maximum (lateral) to minimum (mid-plane) dose ratios are: hips--1.15, shoulders--1.30, and head--1.05, which is shielded by a compensator filter. Organ doses are small intestine, liver and kidneys--1100 rad, lung--1100 to 1200 rad, and heart--1300 rad. Verification dosimetry reveals the prescribed dose is delivered to within +-5%. Details of the dosimetry of this treatment are presented

Radiation and host factors in human thyroid tumors following thymus irradiation

International Nuclear Information System (INIS)

Shore, R.E.; Pasternack, B.S.; Woodard, E.D.; Hempelmann, L.H.

1980-01-01

Thyroid tumor data from the 1971 survey of the Rochester, New York thymus irradiated population are further analyzed to study radiobiological and host factors. The analyses were based on the approx. 2650 irradiated subjects and 4800 sibling controls who had 5 or more years of follow-up. Twenty-four thyroid cancers and 52 thyroid adenomas were found in the irradiated group, and O thyroid cancers and 6 adenomas among the controls. The overall risk estimates were 3.8 thyroid cancers/10 6 persons/yr/rad and 4.5 thyroid adenomas/10 6 persons/yr/rad. The dose-response data (thyroid dose range of 5 to > 1000 rad) for thyroid cancer indicate both a linear and a dose-squared component, but no dose-squared component is evident for thyroid adenomas. At lower total doses (< 400 rad) there was a suggestion that dose fractionation diminished the thyroid cancer response, but a similar fractionation effect was not found for thyroid adenomas. The temporal pattern of tumors suggested an extended plateau of excess tumor production, rather than a wavelike temporal pattern. There was no evidence for an inverse relationship between thyroid radiation dose and thyroid cancer latency. Female and Jewish subjects had a higher risk of radiation-induced thyroid cancer than did their respective counterparts. The additive and multiplicative models of radiation effects were compared with respect to sex differences; neither model provided a superior fit to the data. The tentative nature of the conclusions is stressed because of the relatively small number of thyroid cancers. (author)

RAD18 mediates resistance to ionizing radiation in human glioma cells

International Nuclear Information System (INIS)

Xie, Chen; Wang, Hongwei; Cheng, Hongbin; Li, Jianhua; Wang, Zhi; Yue, Wu

2014-01-01

Highlights: • RAD18 is an important mediator of the IR-induced resistance in glioma cell lines. • RAD18 overexpression confers resistance to IR-mediated apoptosis. • The elevated expression of RAD18 is associated with recurrent GBM who underwent IR therapy. - Abstract: Radioresistance remains a major challenge in the treatment of glioblastoma multiforme (GBM). RAD18 a central regulator of translesion DNA synthesis (TLS), has been shown to play an important role in regulating genomic stability and DNA damage response. In the present study, we investigate the relationship between RAD18 and resistance to ionizing radiation (IR) and examined the expression levels of RAD18 in primary and recurrent GBM specimens. Our results showed that RAD18 is an important mediator of the IR-induced resistance in GBM. The expression level of RAD18 in glioma cells correlates with their resistance to IR. Ectopic expression of RAD18 in RAD18-low A172 glioma cells confers significant resistance to IR treatment. Conversely, depletion of endogenous RAD18 in RAD18-high glioma cells sensitized these cells to IR treatment. Moreover, RAD18 overexpression confers resistance to IR-mediated apoptosis in RAD18-low A172 glioma cells, whereas cells deficient in RAD18 exhibit increased apoptosis induced by IR. Furthermore, knockdown of RAD18 in RAD18-high glioma cells disrupts HR-mediated repair, resulting in increased accumulation of DSB. In addition, clinical data indicated that RAD18 was significantly higher in recurrent GBM samples that were exposed to IR compared with the corresponding primary GBM samples. Collectively, our findings reveal that RAD18 may serve as a key mediator of the IR response and may function as a potential target for circumventing IR resistance in human GBM

Electron dosimetry in irradiation processing with rad-hard diodes

International Nuclear Information System (INIS)

Santos, Thais Cavalheri dos

2012-01-01

This work had the aim of the development of dosimetric systems based on Si special diodes, resistant to radiation damage to online monitoring of irradiation processing using 1.5 MeV electrons energy and for relative dosimetry and clinical electron beam scanning within an energy range of 6 MeV up to 21 MeV. The diodes used were produced by Float Zone standard (FZ), Magnetic Czochralski (MCz) and epitaxy growth (EPI) methods. In order to use the diodes as detectors, they were fixed on alumina base to allow the connection of the polarization electrodes and the signals extraction. After the diode assembly on the base, each one was housed in a black acrylic probe with aluminized Mylar® window and LEMO® connector. With the devices operating in photovoltaic mode, the integration of the current signals as a function of irradiation time allowed obtain the charge produced in the sensitive volume of each diode irradiated. The electron accelerator used for high doses irradiation was the DC 1500/25/4 JOB 188 of the 1.5 MeV installed at the Radiation Technology Center of the IPEN/CNEN-SP. The current profile as function of exposure time, the response repeatability, the sensitivity as function of absorbed dose and the dose response curve were studied for each device. In comparison to FZ diode, we observed a greater decrease in the sensitivity for MCz diode, and good repeatability in both cases. Also, the increasing of the charge with the absorbed dose was well fitted by a second order polynomial function. In the EPI diode characterization, this one exhibited repeatability better than CTA dosimeters applied routinely in radiation processing. The above results indicate the potential use of these radiation hardness Si diodes in online dosimetry to high doses applications. For low doses irradiation were used the linear accelerators KD2 and Primus, both manufactured by Siemens and located at Sirio-Libanes Hospital. The diodes responses were evaluated for electron beams within the

HiRadMat at CERN/SPS - A dedicated facility providing high intensity beam pulses to material samples

CERN Multimedia

Charitonidis, N; Efthymiopoulos, I

2014-01-01

HiRadMat (High Radiation to Materials), constructed in 2011, is a facility at CERN designed to provide high‐intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies (e.g. vacuum windows, high power beam targets, collimators…) can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of up to 7.2 us, and with a maximum pulse energy of 3.4 MJ (3xE13 proton/pulse). In addition to protons, ion beams with energy of 440 GeV/charge and total pulse energy of 21 kJ can be provided. The beam parameters can be tuned to match the needs of each experiment. HiRadMat is not an irradiation facility where large doses on equipment can be accumulated. It is rather a test area designed to perform single pulse experiments to evaluate the effect of high‐intensity pulsed beams on materials or accelerator component assemblies in a controlled environment. The fa‐ cility is designed for a maximum of 1E16 protons per year, dist...

Dielectric behavior of irradiated and nonirradiadiated deoxyribonucleic acid (DNA)-crotonic acid interaction in 5% dextrose solution

International Nuclear Information System (INIS)

Erginun, M.

1980-01-01

Deoxyribonucleic acid (DNA), ex. thymus, dissolved in 5% dextrose, was exposed to gamma radiation at doses between 0-5000 Rads. Crotonic acid dissolved in 5% dextrose was added to this irradiated DNA at t=0 and t=24 hrs after irradiation, in concentrations between 0-1.000 mg/ml. The dielectric behavior of the DNA-irradiation-crotonic acid interaction was investigated at T=20 0 C by pH, permittivity (dielectric constant) and conductivity measurements. The pH, permittivity and conductivity measurements exhibit that the effective and critical conditions for the DNA-irradiation-crotonic acid interaction are; low doses of irradiation (350 Rad.), low concentrations of crotonic acid (0.05-0.100 mg/ml) and the addition of crotonic acid 24 hours after the irradiation. These results support and are in good agreement with those results observed with mammalian cells and laboratory animals when the chemical carcinogens are given in conjunction with radiation

Late vascular effects of whole brain X-irradiation in the mouse

Energy Technology Data Exchange (ETDEWEB)

Yoshii, Y [Tsukuba Univ., Sakma, Ibaraki (Japan). Inst. of Clinical Medicine; Phillips, T L [California Univ., San Francisco (USA). Dept. of Radiation Oncology

1982-01-01

The whole brains of mice were irradiated with 250kVp X-rays at 120 rads min/sup -1/ (1.6 mm Cu HVL, TSD 50 cm), and a histological study was carried out. The dose range of X-irradiation was from 1,300 to 2,500 rads, i.e., 1,300, 1,500, 1,750, 2,000, and 2,500 rads. Eighty-six mice were used for histological examination. For microscopic examination, the mice were killed at regular postirradiation intervals between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. The brains were removed immediately thereafter, fixed in Bouin's solution, and embedded in paraffin. A histological examination was performed by a morphometric estimation of vascular lesions, in which the degree of the damage to the arterial system was scored in whole serial brain section. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectactic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large arteries, were observed. Dose-dependent incidence of the fibrinoid necrosis increased between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 to 87 weeks, and can be used to quantify the vessel injury, and that fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis.

Late vascular effects of whole brain X-irradiation in the mouse

International Nuclear Information System (INIS)

Yoshii, Y.; Phillips, T.L.

1982-01-01

The whole brains of mice were irradiated with 250kVp X-rays at 120 rads min -1 (1.6 mm Cu HVL, TSD 50 cm), and a histological study was carried out. The dose range of X-irradiation was from 1,300 to 2,500 rads, i.e., 1,300, 1,500, 1,750, 2,000, and 2,500 rads. Eighty-six mice were used for histological examination. For microscopic examination, the mice were killed at regular postirradiation intervals between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. The brains were removed immediately thereafter, fixed in Bouin's solution, and embedded in paraffin. A histological examination was performed by a morphometric estimation of vascular lesions, in which the degree of the damage to the arterial system was scored in whole serial brain section. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectactic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large arteries, were observed. Dose-dependent incidence of the fibrinoid necrosis increased between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 to 87 weeks, and can be used to quantify the vessel injury, and that fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis. (Author)

Study on the induction of thyroid tumors in rats using x irradiation in conjunction with a goitrogen. [1 methyl--2 mercaptoimidazole (methimazole)

Energy Technology Data Exchange (ETDEWEB)

Mahler, P.

1979-01-01

The influence of acute localized thyroid x irradiation and chronic goitrogen administration, separately or combined, on thyroid tumor formation in mature female rats was studied. In the first experiment, the radiation doses were 0, 80, 160, 320, or 640 rads, and the dosages of goitrogen were 0, 4, or 40 parts per million (ppM) of 1 methyl - 2 mercaptoimidazole (MMI). The incidence of rats with thyroid tumors in any treated group receiving 0 or 4 ppM MMI was not significantly greater than the incidence in the nontreated control group. However, the incidence in any of the 40 ppM MMI groups was significantly greater than that in the nontreated control group. At all the radiation doses other than 80 rads, the incidence was significantly greater than that in the non-irradiated group. No significant difference was seen in the incidence of rats with thyroid tumors on the basis of radiation dose. The incidence was so high at 80 rads that there was little margin for further increase by increasing the radiation dose. The mean serum thyroxine levels at 40 ppM MMI, 4 ppM MMI, and 0 ppM MMI were 1.9, 3.5, and 3.7 ..mu..g/100 ml, respectively. No markedeffect of thyroid irradiation on mean serum thyroxine levels was seen. In the second experiment, rats receiving 200 ppM MMI and thyroid irradiation were sacrificed at 7-1/2 months after treatment. Nearly all rats in the 0 and 80 rad groups and all in the 160, the 320, and the 640 rad groups had thyroid tumors. In the third experiment, serum T/sub 4/ levels were measured in treated rats. Rats receiving 640 rads + 0 ppM MMI showed a slight decrease in serum T/sub 4/, while no change in serum T/sub 4/ levels was seen in rats receiving 0 rads + 4 ppM MMI or 640 rads + 4 ppM MMI. All rats receiving 40 ppM MMI, regardless of radiation dose, showed decreased serum T/sub 4/ levels.

Gamma irradiation of the brain for prophylaxis of neuroleukemia in children

International Nuclear Information System (INIS)

Ankudinov, V.A.; Moiseenko, E.I.; Mayakova, S.A.; Sotnikov, V.M.

1979-01-01

Demonstrated is experience in treatment of 21 children with acute lymphoblast leukemia. The method of neuroleukemia prophylaxis was used, it included combined chemo- and rediation therapy. After remission and a quintuple endolumber administration of methotrexate to the patients irradiation of the brain on the gamma-therapeutic unit through the open fields was made. The scope of irradiation included the whole of the brain, retrobulbular space, the base of the skull. The lower border of the field was the level of the third cervical vertebra. Irradiation was made from 2 reciprocating side fields, a total seance dose-200-220 rad with daily treatment. The cumulative focal dose for the whole brain was brought to 2500 rad. The analysis of the results with follow-up periods up to 32 months did not reveal a single case of neuroleukemia development. The average life span was 32.8+-1.3 months

Inter-species comparison of the responses of mice and dogs to continuous 60Co γ-irradiation

International Nuclear Information System (INIS)

Norris, W.P.; Tyler, S.A.; Sacher, G.A.

1975-11-01

Young-adult, purebred, beagle dogs were exposed continuously, 22 hours/day, to 60 Co γ-rays until they died. The daily dose rates ranged from 3.5 to 210 rad. At 3.5 rad/day the mean survival time was in excess of 1860 days (the study is still in progress), while at 210 rad/day mean survival time was 13 days. The data are compared to those from previously published information from similarly irradiated mice

Bystander effects, adaptive response and genomic instability induced by prenatal irradiation

Energy Technology Data Exchange (ETDEWEB)

Streffer, Christian [Institute for Science and Ethics, University Duisburg-Essen, Auf dem Sutan 12, D-45239 Essen (Germany)]. E-mail: streffer.essen@t-online.de

2004-12-02

The developing human embryo and fetus undergo very radiosensitive stages during the prenatal development. It is likely that the induction of low dose related effects such as bystander effects, the adaptive response, and genomic instability would have profound effects on embryonic and fetal development. In this paper, I review what has been reported on the induction of these three phenomena in exposed embryos and fetuses. All three phenomena have been shown to occur in murine embryonic or fetal cells and structures, although the induction of an adaptive response (and also likely the induction of bystander effects) are limited in terms of when during development they can be induced and the dose or dose-rate used to treat animals in utero. In contrast, genomic instability can be induced throughout development, and the effects of radiation exposure on genome instability can be observed for long times after irradiation including through pre- and postnatal development and into the next generation of mice. There are clearly strain-specific differences in the induction of these phenomena and all three can lead to long-term detrimental effects. This is true for the adaptive response as well. While induction of an adaptive response can make fetuses more resistant to some gross developmental defects induced by a subsequent high dose challenge with ionizing radiation, the long-term effects of this low dose exposure are detrimental. The negative effects of all three phenomena reflect the complexity of fetal development, a process where even small changes in the timing of gene expression or suppression can have dramatic effects on the pattern of biological events and the subsequent development of the mammalian organism.

RadWorks Project

Data.gov (United States)

National Aeronautics and Space Administration — The RadWorks project's overarching objective is the maturation and demonstration of affordable, enabling solutions to the radiation-related challenges presented to...

Anatomical coverage in elective irradiation of the neck for squamous cell carcinoma of the oral tongue

International Nuclear Information System (INIS)

Meoz, R.T.; Fletcher, G.H.; Lindberg, R.D.

1982-01-01

From January 1954 through December 1978, 146 patients with squamous cell carcinoma of the oral tongue and clinically negative neck had their primary lesion conrolled with irradiation. Metastases to the neck developed later in: 27 of 76 patients (36%) treated by interstitial implantation; nine of 27 patients (33%) who received 2,000 rad in five fractions to the upper neck prior to the implant; eight of 19 (42%) patients who received 5,000 rad through an upper ipsilateral neck field prior to the implant; four of 24 patients (16.6%) who received 5,000 rad through bilateral portals to the upper neck with or without irradiation of the lower neck. In the 43 ipsilateral neck failures, 23 were in the upper jugular chain, (posterior subdigastric nodes), 12 in the mid-jugular, three in the lower jugular, and four in the more anterior part of the subdigastric area. There was one failure in the posterior cervical chain, and five contralateral neck failures. A review of the treatment charts showed that the patients who had an ipsilateral upper neck field only, had smaller portals because the irradiation was tailored to produce shrinkage of the primary tumor prior to needling. To include adequate coverage of the posterior subdigastric nodes (upper jugular), the bodies of the vertebrae must be seen on the simulator films. Also the junction of the subdigastric and the mid-jugular lymphatics must be covered. Although there were only three failures in the lower jugular nodes, it is technically easier to treat the upper mid-jugular nodes through an anterior appositional portal to the lower neck. A dose of 5,000 rad must be given since 2,000 rad, even if delivered in five fractions, gives a failure rate as if there had been no irradiation to the neck

HiRadMat: materials under scrutiny

CERN Multimedia

Anaïs Schaeffer

2011-01-01

CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year.   The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...

Cesium glass irradiation sources

International Nuclear Information System (INIS)

Plodinec, M.J.

1982-01-01

The precipitation process for the decontamination of soluble SRP wastes produces a material whose radioactivity is dominated by 137 Cs. Potentially, this material could be vitrified to produce irradiation sources similar to the Hanford CsCl sources. In this report, process steps necessary for the production of cesium glass irradiation sources (CGS), and the nature of the sources produced, are examined. Three options are considered in detail: direct vitrification of precipitation process waste; direct vitrification of this waste after organic destruction; and vitrification of cesium separated from the precipitation process waste. Direct vitrification is compatible with DWPF equipment, but process rates may be limited by high levels of combustible materials in the off-gas. Organic destruction would allow more rapid processing. In both cases, the source produced has a dose rate of 2 x 10 4 rads/hr at the surface. Cesium separation produces a source with a dose rate of 4 x 10 5 at the surface, which is nearer that of the Hanford sources (2 x 10 6 rads/hr). Additional processing steps would be required, as well as R and D to demonstrate that DWPF equipment is compatible with this intensely radioactive material

Prenatal Diagnosis

Directory of Open Access Journals (Sweden)

Ozge Ozalp Yuregir

2012-02-01

Full Text Available Prenatal diagnosis is the process of determining the health or disease status of the fetus or embryo before birth. The purpose is early detection of diseases and early intervention when required. Prenatal genetic tests comprise of cytogenetic (chromosome assessment and molecular (DNA mutation analysis tests. Prenatal testing enables the early diagnosis of many diseases in risky pregnancies. Furthermore, in the event of a disease, diagnosing prenatally will facilitate the planning of necessary precautions and treatments, both before and after birth. Upon prenatal diagnosis of some diseases, termination of the pregnancy could be possible according to the family's wishes and within the legal frameworks. [Archives Medical Review Journal 2012; 21(1.000: 80-94

Radiation effects on ion-exchange resins. Part II. Gamma irradiation of Dowex 1

International Nuclear Information System (INIS)

Kazanjian, A.R.; Horrell, D.R.

1975-01-01

The effects were determined of gamma radiation on the anion exchange resin, Dowex 1. Part I on Dowex 50W was reported May 10, 1974. The exchange capacity (both strong and weak base), moisture content, radiolysis products, and physical deterioration of the resin were analyzed after irradiation with doses up to 6.9 x 10 8 rads. The resin capacity decreased approximately 50 percent after a radiation dose of 4 x 10 8 rads. Resin irradiated, when air dried in the nitrate form, showed more stability than resin irradiated in 7N nitric acid (HNO 3 ), which in turn showed more stability than resin irradiated when air dried in the chloride form. Radiation decreased the strong base capacity to a greater extent than the total capacity. The result indicates that some of the quarternary ammonium groups were transformed to secondary and tertiary amine groups that have weak base ion-exchange capability. (U.S.)

Effect of daily low dose gamma irradiation on growth and differentiation of human myeloid leukaemic bone marrow in diffusion chambers

Energy Technology Data Exchange (ETDEWEB)

Greenberger, J S [Joint Center for Radiation Therapy, Department of Radiation and Sidney Farber Cancer Institute; Chang, J M; King, V; Fulmer, S; Balzuno, S; Moloney, W C [Division of Hematology, Department of Medicine, Brigham and Women' s Hospital Harvard Medical School, Boston, USA

1981-01-01

Bone marrow from each of 8 untreated patients with myeloproliferative disorders was grown in diffusion chambers in 760 rad total body irradiated rats. Rats were exposed to 11.5, 57.5, or 108.5 rad daily for 14-21 and cell growth compared to that detected in unirradiated chambers. Cells from acute myelogenous leukaemia patients exposed to 11.5 rad per d grew for 11-21 d and there was no consistent stimulation of differentiation of immature granulocytic cells to mature granulocytes that was attributable to irradiation. Cells from a chronic myeloid leukaemia patient in chronic phase or blast crisis, and a polycythaemia vera patient with myeloid metaplasia showed signigicant morphologic differentiation from immature to mature granulocytes in control chambers with no additional effect of daily irradiation. Marrow specimens from 2 AML patients exposed to each of 3 daily dose fractions over 14 d revealed a dose-dependent decrease in immature granulocytes with no persistent increase in mature granulocytes. In both irradiated and control chambers, macrophages increased over 21 d. Thus, cells from patients with myeloprofilerative disorders may not necessarily differentiate to mature granulocytes following in vivo exposure to ionizing irradiation.

Graft irradiation abrogates graft-versus-host disease in combined pancreas-spleen transplantation

International Nuclear Information System (INIS)

Schulak, J.A.; Sharp, W.J.

1986-01-01

A model of combined pancreas-spleen transplantation (PST) was studied in LBN F1 recipients of Lewis grafts in order to evaluate the efficacy of pretransplant graft irradiation in preventing lethal graft-versus-host disease (GVHD). Recipients of unmodified PST uniformly developed severe GVHD and died (MST = 16.7 +/- 3.8 days). Whole body donor irradiation with either 500 or 250 rad prevented lethal GVHD. Similarly, ex vivo graft irradiation with either 1000 or 500 rad also resulted in normal weight gain, graft function, and host survival for the 6-week study period. Conversely, delay of graft irradiation until 3 days after transplantation failed to prevent this complication (MST = 15.8 +/- 3.7 days). Recipients of irradiated grafts displayed glucose tolerance tests that were identical to those in the control group indicating that the doses of radiation employed in these experiments were not deleterious to islet function. Irradiated spleen grafts appeared histologically normal at 6 weeks after transplantation. Cells derived from these grafts failed to stimulate lymph node enlargement in a popliteal lymph node assay for GVHD, suggesting that these spleens may have become repopulated with host cells. These experiments confirm that PST has the potential to cause lethal GVHD and suggest that pretransplant graft irradiation may be used to prevent its occurrence

A Rad53 independent function of Rad9 becomes crucial for genome maintenance in the absence of the Recq helicase Sgs1.

Directory of Open Access Journals (Sweden)

Ida Nielsen

Full Text Available The conserved family of RecQ DNA helicases consists of caretaker tumour suppressors, that defend genome integrity by acting on several pathways of DNA repair that maintain genome stability. In budding yeast, Sgs1 is the sole RecQ helicase and it has been implicated in checkpoint responses, replisome stability and dissolution of double Holliday junctions during homologous recombination. In this study we investigate a possible genetic interaction between SGS1 and RAD9 in the cellular response to methyl methane sulphonate (MMS induced damage and compare this with the genetic interaction between SGS1 and RAD24. The Rad9 protein, an adaptor for effector kinase activation, plays well-characterized roles in the DNA damage checkpoint response, whereas Rad24 is characterized as a sensor protein also in the DNA damage checkpoint response. Here we unveil novel insights into the cellular response to MMS-induced damage. Specifically, we show a strong synergistic functionality between SGS1 and RAD9 for recovery from MMS induced damage and for suppression of gross chromosomal rearrangements, which is not the case for SGS1 and RAD24. Intriguingly, it is a Rad53 independent function of Rad9, which becomes crucial for genome maintenance in the absence of Sgs1. Despite this, our dissection of the MMS checkpoint response reveals parallel, but unequal pathways for Rad53 activation and highlights significant differences between MMS- and hydroxyurea (HU-induced checkpoint responses with relation to the requirement of the Sgs1 interacting partner Topoisomerase III (Top3. Thus, whereas earlier studies have documented a Top3-independent role of Sgs1 for an HU-induced checkpoint response, we show here that upon MMS treatment, Sgs1 and Top3 together define a minor but parallel pathway to that of Rad9.

Relationship of colony-stimulating activity to apparent kill of human colony-forming cells by irradiation and hydroxyurea

International Nuclear Information System (INIS)

Broxmeyer, H.E.; Galbraith, P.R.; Baker, F.L.

1976-01-01

Suspensions of human bone marrow cells were subjected to 137 Cs irradiation in vitro and then cultured in semisolid agar medium. Cultures of irradiated cells were stimulated with colony-stimulating activity (CSA) of different potencies, and it was found that the amount of stimulation applied to cultures influenced the apparent kill of colony-forming cells (CFC). It was also found that the effects of irradiation on colony formation were not confined to CFC kill since medium conditioned by cells during irradiation exhibited stimulatory and inhibitory properties after treatment by 600 and 1000 rads, respectively. Studies in which irradiated cells were pretreated with hydroxyurea indicated that CFC in the DNA synthetic phase of the cell cycle were particularly sensitive to low doses of irradiation. The proliferative capacity of CFC surviving 1000 rads was undiminished as judged by their ability to form large colonies. Estimates of CFC kill by hydroxyurea were also affected by the level of CSA

Survival of mouse testicular stem cells after γ or neutron irradiation

International Nuclear Information System (INIS)

Lu, C.C.; Meistrich, M.L.; Thames, H.D. Jr.

1980-01-01

The survival of mouse testicular stem cells after γ or neutron irradiation was measured by counts of repopulated tubular cross sections and by the numbers of differentiated spermatogenic cells produced. The numbers of such cells were determined either by sperm head counts of the X-isozyme of lactate dehydrogenase enzyme levels. Qualitatively similar results were obtained with all three assays. The results have confirmed that, with C3H mice, stem-cell survival is higher when the γ-radiation dose is fractionated by a 24-h interval. Single-dose γ-radiaton survival curves for the stem cell had large shoulders and also showed the presence of a radioresistant subpopulation which predominated after doses greater than 600 rad. Part of the shoulder must have resulted from repair of sublethal damage since neutron irradiation produced survival curves with smaller shoulders. The relative biological effectiveness for stem-cell killing for these neutrons (mean energy, 22 MeV) varied from about 2.9 at 10 rad of γ radiation to 2.2 at 600 rad

RadNet Air Quality (Fixed Station) Data

Data.gov (United States)

U.S. Environmental Protection Agency — RadNet is a national network of monitoring stations that regularly collect air for analysis of radioactivity. The RadNet network, which has stations in each State,...

The role of total body irradiation in preparation for bone marrow transplantation in acute leukaemia. A review

International Nuclear Information System (INIS)

Zwaan, F.E.

1979-01-01

From extrapolation obtained from animal studies and radiation accidents, it is assumed that for man the LD 50 (30) will be between 300-500 rads total body irradiation (TBI) and the LD 100 at least 600 rads TBI. A dose of 1000 rads TBI is generally used in man for conditioning for bone marrow transplantation. In acute leukemia, total body irradiation is usually associated with cytoreductive chemotherapy. In Seattle 110 patients underwent bone marrow transplantation for acute leukemia in relapse. 15 patients became long term survivors. The main cause of failure were GVH, interstitial pneumonitis and leukemic relapse. New attempts are being made to improve the results: (1) better cytoreductive therapy preceding transplantation, (2) bone marrow transplantation during remission of the disease, (3) prevention of interstitial pneumonitis by modifications of the TBI technique

Research on the therapeutics of intense abdominal irradiations in pigs

International Nuclear Information System (INIS)

Daburon, F.; Tricaud, Y.; Bourhoven, D.; Hay, J.M.

1979-01-01

Tests of surgical treatments (graft of small intestine, and partial enterectomy before or after irradiation) and dietic treatments (continuous parenteral feeding) were carried out on 80 pigs irradiated over the posterior half of the body with doses of between 950 and 1750 rad at mid plane. The results relate to clinical symptoms, survivals, haematology, and histopathology; nutritional aspects were studied by means of evaluation of balances (nitrogen, lipids, and minerals) and absorption tests ( 58 Co - Vit. B 12 and iodised lipids). Above 1200 rad recuperation of the digestive system did not in general make prolonged survival possible; in addition to intestinal lesions, renal and especially pancreatic atrophy appeared, whose consequences appeared to be determinative as regards the nutrition and hence the survival of the animals. (orig.) 891 MG/orig. 892 CKA [de

Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

International Nuclear Information System (INIS)

Wang Wen; Hu Liqin; Cheng Mengyun; Long Pengcheng

2015-01-01

The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom, which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team. The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models. The differences were due to the racial and anatomical differences in organ mass and inter-organ distance. The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females. (authors)

A study of the behaviour of irradiated or unirradiated grafts in the camera aquosa of irradiated and unirradiated animals; Etude du comportement d'un greffon irradie ou non, transplante dans la chambre anterieure de l'oeil d'un animal irradie ou non

Energy Technology Data Exchange (ETDEWEB)

Djalali-Behzad, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-06-01

Following grafts of new born mice spinal ganglia in the 'camera aquosa' of adult mice, the authors tried hematopoietic tissue grafts in the same conditions. The growth of iso-logous and hetero-logous bone marrow in the 'camera aquosa' showed that this tissue, even after exposure to supralethal doses, was capable of survival and growth. A counter-experiment with non irradiated bone marrow grafts in the 'camera aquosa' of rats delivered 700 rads led to the conclusion that the environment, intoxicated by exposure, acted on the graft so that after vascularization it became unable to grow. (author) [French] Apres avoir greffe des ganglions rachidiens de souriceaux nouveaux-nes dans la chambre anterieure de l'oeil de souris adultes, l'auteur a tente de greffer du tissu hematopoietique de la meme facon. La proliferation de la moelle osseuse isologue et heterologue, dans la chambre anterieure de l'oeil, lui a permis de mettre en evidence une certaine capacite de survie et de proliferation de ce tissu irradie meme a dose supraletale. Par une contre-experimentation, c'est-a-dire par la greffe de moelle non irradiee dans la chambre anterieure de rats irradies a 700 rads, il conclut que le milieu ambiant, intoxique par l'irradiation, agit sur le greffon de telle sorte que ce dernier, apres s'etre vascularise, devient depourvu de son aptitude de proliferation. (auteur)

Extrahepatic bile duct carcinoma treated by intraluminal irradiation with iridium-192 wire. Report of a case

Energy Technology Data Exchange (ETDEWEB)

Ikeda, H; Kuroda, T; Uchida, H [Osaka Univ. (Japan). Faculty of Medicine

1980-08-01

A 57-year-old male with obstructive jaundice was diagnosed extrahepatic bile duct carcinoma at bifurcation by percutaneous transhepatic cholangiography (PTC). He was treated 3,300 rad of external irradiation and then intraluminal irradiation using the Iridium-192 wire by two times with the aid of PTC internal drainage, each was given by the dose of 1,600 rad at 5 mm inside the tumor from the PTC-tube. He had been well for about 1 year and then died because of ascites and cachexia. Autopsy revealed only microscopic tumor cells remaining around the common duct below the cystic junction. It was confirmed that intraluminal irradiation using the Iridium-192 wire was potentially curable and easily applicable to the bile duct carcinoma.

RadNet Air Data From Sacramento, CA

Science.gov (United States)

This page presents radiation air monitoring and air filter analysis data for Sacramento, CA from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

RadNet Air Data From Honolulu, HI

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This page presents radiation air monitoring and air filter analysis data for Honolulu, HI from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

RadNet Air Data From Houston, TX

Science.gov (United States)

This page presents radiation air monitoring and air filter analysis data for Houston, TX from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

RadNet Air Data From Austin, TX

Science.gov (United States)

This page presents radiation air monitoring and air filter analysis data for Austin, TX from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

RadNet Air Data From Orlando, FL

Science.gov (United States)

This page presents radiation air monitoring and air filter analysis data for Orlando, FL from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

Prenatal irradiation: nitric oxide and oxidative stress roles in radiation-induced apoptosis of the developing central nervous system

International Nuclear Information System (INIS)

Sanjurjo, Julieta

2001-01-01

Full text: The effects of prenatal irradiation on developing brain should be considered at cellular, structural and functional levels, integrating the information obtained from different sources in an appropriated model to explain the mechanisms involved in neuronal damage. That would permit to make risk estimations and improve radiological protection. Human brain is especially sensitive to ionizing radiation during certain stages of prenatal development. At doses such as those received by Hiroshima and Nagasaki's atomic bomb explosions survivors that were prenatally exposed, the maximum risk was to those exposed between the 8th and 15th weeks of gestation, in coincidence with the highest rate of neuron production and its migration to the brain cortex. The major effect produced on both, brain growth and development, was the augmentation of the Severe Mental Retardation (SMR) incidence. Radiation-induced apoptosis of neuronal progenitors should be considered as one of the factors associated with this pathology, apart from those of migration and synaptogenesis. Apoptosis is an innate and evolutionally conserved process by which the cells provoke the inactivation, disorganisation and degradation of their structural and functional components in a systematic fashion, with the aim of producing its own death. It is also the main cell death mechanism induced by low linear energy transfer (LET) ionizing radiation in developing Central Nervous System (CNS). Radioinduced apoptosis characterization during the different developmental stages, its kinetics and the possible implicated mechanisms (like oxidative injury and nitric oxide) was done using an 'in vitro' system of cortical micro masses (primary cultures of brain cortex cells) from rat embryo brains. Cell cultures were exposed to a single dose of gamma radiation, between 0,2 and 2 Gy, supplied by a Co 60 source (Picker C4M60) at a 70 cm distance with a field area size of 25 cm x 25 cm and at a 0,34 Gy/minute dose rate

Effects of the rad52 gene on recombination in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, S.; Prakash, L.; Burke, W.; Montelone, B.A.

1980-01-01

Effects of the rad 52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, uv-induced and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Both intra and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the his1-1/his1-315 and trp-5-2/trp5-48 heteroalleles. Gene-centromere recombination also was not observed in rad/52/rad52 diploids. No γ-ray- or uv-induced intragenic mitotic recombination is seen in rad52/rad52 diploids. The rate of spontaneous mitotic recombination is lowered five-fold at the his1-1/his1-315 and leu1-c/leu1-12 heteroalleles. Spontaneous reversion rates of both his1-1 and his1-315 were elevated 10 to 20 fold in rad52/rad52 diploids. The RAD52 gene function is required for spontaneous mitotic recombination, uv- and γ-ray-induced mitotic recombination and mitotic recombination

Lethal effect after whole-body irradiation on mouse with various photon radiations

International Nuclear Information System (INIS)

Kohda, Shizuo

1976-01-01

The dependence of mortality on the quality of radiation was investigated in ICR mice after wholebody irradiation with 200 kV x-ray, 60 Co γ-ray, or 10 MV x-ray. With respect to the 30 day mortality, LD 50 values were estimated as 606 rad for 200 kV x-ray and as 713 rad both for 60 Co γ-ray and for 10 MV x-ray. Hence, the value of relative biological effectiveness (RBE) to that for 200 kV x-ray was 0.850, while the value decreased with increasing the mortality rate. The value extrapolated to 100% mortality was estimated as 0.6. These results were valid for either 7 or 8 week mice, but the life span of 7 week mice after the irradiation was 3 days shorter than that of 8 week mice. These findings resulted in following conclusions: 1) There are no qualitative differences between 10 MV x-ray and 60 Co γ-ray irradiations. 2) The biological effects after 10 MV x-ray and 60 Co γ-ray irradiations are reduced with increased killing rate, compared with that after 200 kV x-ray irradiations. (Evans, J.)

Rad9 Has a Functional Role in Human Prostate Carcinogenesis

Science.gov (United States)

Zhu, Aiping; Zhang, Charles Xia; Lieberman, Howard B.

2013-01-01

Prostate cancer is currently the most common type of neoplasm found in American men, other than skin cancer, and is the second leading cause of cancer death in males. Because cell cycle checkpoint proteins stabilize the genome, the relationship of one such protein, Rad9, to prostate cancer was investigated. We found that four prostate cancer cell lines (CWR22, DU145, LNCaP, and PC-3), relative to PrEC normal prostate cells, have aberrantly high levels of Rad9 protein. The 3′-end region of intron 2 of Rad9 in DU145 cells is hypermethylated at CpG islands, and treatment with 5′-aza-2′-deoxycytidine restores near-normal levels of methylation and reduces Rad9 protein abundance. Southern blot analyses indicate that PC-3 cells contain an amplified Rad9 copy number. Therefore, we provide evidence that Rad9 levels are high in prostate cancer cells due at least in part to aberrant methylation or gene amplification. The effectiveness of small interfering RNA to lower Rad9 protein levels in CWR22, DU145, and PC-3 cells correlated with reduction of tumorigenicity in nude mice, indicating that Rad9 actively contributes to the disease. Rad9 protein levels were high in 153 of 339 human prostate tumor biopsy samples examined and detectable in only 2 of 52 noncancerous prostate tissues. There was a strong correlation between Rad9 protein abundance and cancer stage. Rad9 protein level can thus provide a biomarker for advanced prostate cancer and is causally related to the disease, suggesting the potential for developing novel diagnostic, prognostic, and therapeutic tools based on detection or manipulation of Rad9 protein abundance. PMID:18316588

Survival of human osteosarcoma cells and normal human fibroblasts following alpha particle irradiation

International Nuclear Information System (INIS)

Lloyd, E.L.; Gemmell, M.A.

1981-01-01

Cell survival of human osteosarcoma cells in culture following alpha particle irradiation is reported here for the first time. The osteosarcoma cell line (TE-85) is found to be less sensitive to inactivation by 5.6 MeV alpha particles (LET 86 keV/μm) than normal diploid human fibroblasts (NFS). Values for the mean lethal doses were estimated to be 103 rads for the TE-85 cells compared with 68 rads for the NFS cultures irradiated under identical conditions. It is postulated that the aneuploidy of the tumor cells with increased DNA chromosomal material may confer a selective advantage for the survival of tumor cells relative to normal cells with diploid chromosomes

RAD51B in Familial Breast Cancer

OpenAIRE

Pelttari, L.M.; Khan, S.; et al.,

2016-01-01

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737\\ud and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast\\ud cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer\\ud predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the\\ud coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for\\ud identifi...

RAD51B in familial breast cancer

OpenAIRE

Pelttari, LM; Khan, S; Vuorela, M; Kiiski, JI; Vilske, S; Nevanlinna, V; Ranta, S; Schleutker, J; Winqvist, R; Kallioniemi, A; Dörk, T; Bogdanova, NV; Figueroa, J; Pharoah, PDP; Schmidt, MK

2016-01-01

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possi...

Can prenatal low-dose irradiation affect behavior of adult rats?

International Nuclear Information System (INIS)

Smajda, B.; Tomasova, L.; Kokocova, N.

2011-01-01

The aim of our study was to determine whether exposure of very low dose gamma-rays during the critical phase of brain development affects some selected behavioral parameters in adult rats. Pregnant female Wistar rats were irradiated with 1 Gy gamma-rays from a cobalt source at 17 th day of pregnancy. The progeniture of irradiated as well as non-irradiated females have undergone behavioral tests at the age of 3 months. Irradiated animals exhibited lower locomotor and exploratory activity in the open field test. (authors)

Effects of prenatal brain irradiation as a result of the Chernobyl accident

International Nuclear Information System (INIS)

Nyagu, A.I.; Loganovsky, K.N.; Repin, V.S.; Bomko, M.A.; Pott-Born, R.

2004-01-01

A cohort of 154 children born between April 26, 1986 and February 26, 1987 to mothers who had been evacuated from Pripyat to Kiev, and 143 classmates from Kiev were examined. Individual dose reconstruction of the children exposed in utero was carried out considering internal and external exposure. Prenatal equivalent brain doses were 19.2 ± 11.3 mSv and 0.8 ± 0.2 mSv for the exposed and control groups, respectively. Thyroid doses in utero were 760.4 ± 631.8.1 mSv and 44.5 ± 43.3 mSv for the exposed and control groups, correspondingly. There were 20 children from Pripyat town (13.2%) who had been exposed in utero to thyroid doses >1 Sv. The prenatally exposed children show significantly more diseases of the nervous system and mental disorders. Among mothers of the exposed group of children with the neuropsychiatric disorders there are much more depression and somatization, as well as mental disorders

A novel interation of nucleolin with Rad51

International Nuclear Information System (INIS)

De, Ananya; Donahue, Sarah L.; Tabah, Azah; Castro, Nancy E.; Mraz, Naomi; Cruise, Jennifer L.; Campbell, Colin

2006-01-01

Nucleolin associates with various DNA repair, recombination, and replication proteins, and possesses DNA helicase, strand annealing, and strand pairing activities. Examination of nuclear protein extracts from human somatic cells revealed that nucleolin and Rad51 co-immunoprecipitate. Furthermore, purified recombinant Rad51 associates with in vitro transcribed and translated nucleolin. Electroporation-mediated introduction of anti-nucleolin antibody resulted in a 10- to 20-fold reduction in intra-plasmid homologous recombination activity in human fibrosarcoma cells. Additionally, introduction of anti-nucleolin antibody sensitized cells to death induced by the topoisomerase II inhibitor, amsacrine. Introduction of anti-Rad51 antibody also reduced intra-plasmid homologous recombination activity and induced hypersensitivity to amsacrine-induced cell death. Co-introduction of anti-nucleolin and anti-Rad51 antibodies did not produce additive effects on homologous recombination or on cellular sensitivity to amsacrine. The association of the two proteins raises the intriguing possibility that nucleolin binding to Rad51 may function to regulate homologous recombinational repair of chromosomal DNA

Effects of sub-lethal dose of gamma-irradiation on levels of acid phosphatase in cerebellum of pigeons

International Nuclear Information System (INIS)

Shah, V.C.; Gadhia, P.K.

1980-01-01

The changes in the activities of acid phosphatase in the sham-irradiated and γ-irradiated cerebellum of pigeons have been studied both biochemically as well as histochemically after 400 rads. The specific activity of acid phosphatase decreased significantly after 48h and 72h of irradiation. The histochemical observations following total body irradiation confirmed the results obtained by quantitative biochemical studies. (author)

Late effects of x-irradiation in rats, 1

International Nuclear Information System (INIS)

Jankovic-Stejin, V.D.; Kanazir, D.T.

1978-01-01

The present cytogenetic study was made on the bone marrow cells of 48 male rats killed after 9 to 17 months following acute whole-body x-irradiation. We found that exposure to a dose of 700 rads of x-rays, delivered to animals at a high dose-rate (100 rads/min) resulted in a widespread karyotype variability. The number of cell types were existing independently in the haemopoietic tissue within the first week after irradiation, decreased with time. The selection process of persisting abnormalities as well a further evolution of the cells with new karyotypes to clones, were evident after a month following irradiation. Consequently, the analysis of haemopoietic tissue revealed, in 92% of the late survivors, a genetically heterogeneous cell population in which the number of normal diploid cells decreased to a considerable extent. Clones increased in size with elapsing time from exposure to radiation. Thus, the mean clone cell frequency for animals killed after 9 to 17 months following irradiation ranged from 20.6 +- 3.42% to 61.6 +- 4.26%. Analysis of the data showed a significant positive correlation between development of clones in vivo and the survival time after irradiation (r = 0.820; P<0.01). For such a finding, the occurrence of large clones especially in the bone marrow of rats with growing tumors was of the great influence. Relationship between the degree of mutagenesis on the chromosome level and the process of tumor advancement is discussed. (auth.)

Group prenatal care.

Science.gov (United States)

Mazzoni, Sara E; Carter, Ebony B

2017-06-01

Patients participating in group prenatal care gather together with women of similar gestational ages and 2 providers who cofacilitate an educational session after a brief medical assessment. The model was first described in the 1990s by a midwife for low-risk patients and is now practiced by midwives and physicians for both low-risk patients and some high-risk patients, such as those with diabetes. The majority of literature on group prenatal care uses CenteringPregnancy, the most popular model. The first randomized controlled trial of CenteringPregnancy showed that it reduced the risk of preterm birth in low-risk women. However, recent meta-analyses have shown similar rates of preterm birth, low birthweight, and neonatal intensive care unit admission between women participating in group prenatal care and individual prenatal care. There may be subgroups, such as African Americans, who benefit from this type of prenatal care with significantly lower rates of preterm birth. Group prenatal care seems to result in increased patient satisfaction and knowledge and use of postpartum family planning as well as improved weight gain parameters. The literature is inconclusive regarding breast-feeding, stress, depression, and positive health behaviors, although it is theorized that group prenatal care positively affects these outcomes. It is unclear whether group prenatal care results in cost savings, although it may in large-volume practices if each group consists of approximately 8-10 women. Group prenatal care requires a significant paradigm shift. It can be difficult to implement and sustain. More randomized trials are needed to ascertain the true benefits of the model, best practices for implementation, and subgroups who may benefit most from this innovative way to provide prenatal care. In short, group prenatal care is an innovative and promising model with comparable pregnancy outcomes to individual prenatal care in the general population and improved outcomes in some

Cytogenetic determination of the effect of irradiation on in vitro lymphocyte transformation rates

International Nuclear Information System (INIS)

Lloyd, D.C.; Dolphin, G.W.; Purrott, R.J.

1976-01-01

The effect of x irradiation on the yield of transformed cells in 48-hr cultures has been studied in human peripheral-blood lymphocytes. Cytogenetic damage was used as a marker, aberration yields being obtained for mixed cultures prepared from equal numbers of normal and irradiated lymphocytes and from pure cultures of irradiated cells. Comparison of data from these two types of culture shows that the yield observed ranged from 90 percent of that expected at 50 rads to 11 percent at 700 rads. Poisson analysis demonstrated that for all doses, cells with high levels of structural damage were not selectively eliminated. The extent to which mitotic delay contributes to the reduction in numbers of transformed cells was examined by varying the time in cultures from 36 to 72 hr. The implication of this work in the field of radiation-dose estimation by chromosome-aberration analysis is discussed

Comparison of clastogen-induced gene expression profiles in wild-type and DNA repair-deficient Rad54/Rad54B cells

Directory of Open Access Journals (Sweden)

van Benthem Jan

2010-01-01

Full Text Available Abstract Background Previously we found that Rad54/Rad54B cells are more sensitive towards mitomycin C (MMC as compared to wild-type (WT cells. This difference in sensitivity was absent upon exposure to other clastogens like bleomycin (BLM and γ-radiation. In order to get further insight into possible underlying mechanisms, gene expression changes in WT and Rad54/Rad54B MEFs (mouse embryonic fibroblasts after exposure to the clastogens MMC and BLM were investigated. Exposures of these cells to mutagens (N-ac-AAF and ENU and vehicle were taken as controls. Results Most exposures resulted in an induction of DNA damage signaling and apoptosis genes and a reduced expression of cell division genes in cells of both genotypes. As expected, responses to N-ac-AAF were very similar in both genotypes. ENU exposure did not lead to significant gene expression changes in cells of both genotypes, presumably due to its short half-life. Gene expression responses to clastogens, however, showed a genotype-dependent effect for BLM and MMC. MMC treated Rad54/Rad54B MEFs showed no induction of p53-signaling, DNA damage response and apoptosis as seen for all the other treatments. Conclusion These data support our finding that different types of clastogens exist and that responses to these types depend on the DNA repair status of the cells.

Gamma-irradiation of tomatoes

International Nuclear Information System (INIS)

Tencheva, S.; Todorov, S.

1975-01-01

The influence of gamma-ray on tomatoes picked in a pink-red ripening stage, good for consumption, is studied. For that purpose tomatoes of ''Pioneer 2'' variety packed in perforated 500 g plastic bags were irradiated on a gamma device (Cobalt-60) at a dose power of 1900 rad/min with doses 200 or 300 krad. Samples were stored after irradiation at room temperature (20 - 22sup(o)C). Microbiological studies demonstrated that 44 resp. 99.96 per cent of the initial number of microorganisms was destroyed after irradiation with 200 resp. 300 krad. The time required for the number of microorganisms to be restored was accordingly increased. Irradiation delayed tomato ripening by 4 to 6 days, demonstrable by the reduced content of the basic staining substances - carotene and licopine. Immediately after irradiation the ascorbic acid content was reduced by an average of 13 per cent. After 18 days the amount of ascorbic acid in irradiated tomatoes was increased to a higher than the starting level, this is attributed to reductone formation during irradiation. The elevated total sugar content shown to be invert sugar was due to further tomato ripening. (Ch.K.)

Irradiated eggs and chicks in broilers: 3- carcass and blood parameters

International Nuclear Information System (INIS)

Shebaita, M.K.; Abdelaal, A.E.; Fahmy, M.O.; Ezzat, I.E.; EL-Barkouky, E.E.; Salem, M.A.I.

1991-01-01

This study was carried out on 200 broiler chicks (Hcbbard) representing 3 groups of non-irradiated, irradiated eggs and 4-day-old irradiated chicks (exposed to gamma rays of Co-60). The doses used were 500 and 1000 rad.Half the chickens within each group and within each dose level were treated with vitamin C (50 mg/chick/day) in the drinking water. Carcass analysis, giblets weight and some blood parameters were measured individually in five chicks from each group at 2,4,5 and 6 weeks of age. The data revealed that the exposure of either eggs or chicks to gamma-rays induced a highly significant decrease in liver, heart and gizzard weights. The effect was more pronounced in the irradiated chicks than that in the chicks of irradiated eggs particularly at the dose level of 1000 rad. Except few sporadic cases noticed at different age intervals, no appreciable changes in either carcass chemical analysis (water, fat, protein and ash contents) or blood parameters (RBCs, Hb, PCV, Ca, P, cholesterol, total protein, albumin and globulin) were observed. It seems that the giblets were more sensitive to and reflect the hazardous effects of ionizing radiation than carcass chemical analysis and/or Blood parameters

Molecular anatomy of the recombination mediator function of Saccharomyces cerevisiae Rad52

DEFF Research Database (Denmark)

Seong, C.; Sehorn, M.G.; Plate, Iben

2008-01-01

A helical filament of Rad51 on single-strand DNA (ssDNA), called the presynaptic filament, catalyzes DNA joint formation during homologous recombination. Rad52 facilitates presynaptic filament assembly, and this recombination mediator activity is thought to rely on the interactions of Rad52...... with Rad51, the ssDNA-binding protein RPA, and ssDNA. The N-terminal region of Rad52, which has DNA binding activity and an oligomeric structure, is thought to be crucial for mediator activity and recombination. Unexpectedly, we find that the C-terminal region of Rad52 also harbors a DNA binding function....... Importantly, the Rad52 C-terminal portion alone can promote Rad51 presynaptic filament assembly. The middle portion of Rad52 associates with DNA-bound RPA and contributes to the recombination mediator activity. Accordingly, expression of a protein species that harbors the middle and C-terminal regions of Rad...

[Genetic control of mitotic crossing-over in yeasts. III. Induction by 8-methoxypsoralen and long-wave UV irradiation (lambda=365 nm)].

Science.gov (United States)

Fedorova, I V; Marfin, S V

1982-02-01

The lethal effect of 8-methoxypsoralen (8-MOP) plus 365 nm light has been studied in haploid radiosensitive strains of Saccharomyces cerevisiae. The diploid of wild type and the diploid homozygous for the rad2 mutation (this mutation blocks the excision of UV-induced pyrimidine dimers) were more resistant to the lethal effect of 8-MOP plus 365 nm light than the haploid of wild type and rad2 haploid, respectively. The diploid homozygous for rad54 mutation (the mutation blocks the repair of double-strand breaks in DNA) was more sensitive than haploid rad54. The method of repeated irradiation allowed to study the capacity of radiosensitive diploids to remove monoadducts induced by 8-MOP in DNA. This process was very effective in diploids of wild type and in the rad54 rad54 diploid, while the rad2 rad2 diploid was characterized by nearly complete absence of monoadduct excision. The study of mitotic crossing over and mitotic segregation in yeast diploids, containing a pair of complementing alleles of the ade2 gene (red/pink) has shown a very high recombinogenic effect of 8-MOP plus 365 nm light. The rad2 mutation slightly increased the frequency of mitotic segregation and mitotic crossing over. The rad54 mutation decreased the frequency of mitotic segregation and entirely suppressed mitotic crossing over. The method of repeated irradiation showed that the cross-links, but not monoadducts, are the main cause of high recombinogenic effect of 8-MOP plus 365 nm light. The possible participation of different repair systems in recombinational processes induced by 8-MOP in yeast cells is discussed.

Evaluation of cell regeneration of bone marrow after fractionated irradiation of mouse in toto

International Nuclear Information System (INIS)

Maisin, H.; Evercoren, A. van; Anckaert, M.A.; Coster, B.M. de

1979-01-01

We have studied the recovery for mice bone marrow cells after fractionated irradiation of the whole body. The additional dose (Dr) to obtain a given biological effect if the irradiation is split in two equal subfractions (2 Di) separated by a short interval of time (i) is 40 rad per day when the interval of time between the two irradiations is lenghtened of one day [fr

Ultrastructural changes in rabbits liver after irradiation

Energy Technology Data Exchange (ETDEWEB)

Cieciura, L; Bartel, H; Orkisz, S

1975-01-01

Ultrastructural changes in hepatocytes observed 1 to 30 days after irradiation are presented. The dose absorbed was 550 rad (LD 33/30). Electron microscopy studies showed that early and more distinct changes were observed in mitochondria within 24 hours. Disintegration of endoplasmic reticulum and vacuolization of cytoplasm were seen on the 3rd day after irradiation. From the 9th day, the ultrastructural picture of hepatocytes became normal. In the liver in this period the increase in number of large hypertrophic macrophages was noted.

Effects of the rad52 gene on recombination in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, S.; Prakash, L.; Burke, W.; Montelone, B.A.

1979-01-01

Effects of the rad52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, uv-induced, and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Intra- and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the hisl-1/hisl-315 and trp5-2/trp5-48 heteroalleles. Gene-centromere recombination was also not observed in rad52/rad52 diploids. No γ-ray-induced intragenic mitotic recombination is seen in rad52/rad52 diploids and uv-induced intragenic recombination is greatly reduced. However, spontaneous mitotic recombination is not similarly affected. The RAD52 gene thus functions in recombination in meiosis and in γ-ray and uv-induced mitotic recombination but not in spontaneous mitotic recombination

Spectral difference method applied in determination of beta-carotene, chlorophyll a and b from irradiated seeds of Calendula Officinalis

International Nuclear Information System (INIS)

Cucu, Delia-Irina; Dorobantu, Ioan

2002-01-01

Beta-carotene is part of the class of the carotenoid pigments that have a special function in the pigmentation of flowers and fruits. These pigments are essential in photosynthesis where they are retaining energy and are photoprotectors by forming the redox system. They are also precursors of vitamin A, pigments involved in the process of seeing. Beta-carotene is responsible for the growth and development of organisms, for the protection and recovery of epithelial tissue, etc. Next to chlorophyll, carotenoids are the major components of the complex pigment-protein from the thylacoide membrane, and some of them, such as beta-carotene, were for a long time considered to be protecting the membrane against destructive events caused by the over excitement of the chlorophyll. This paper presents spectral difference method for physico-chemical characterisation of three components (beta-carotene, chlorophyll a and b) from Calendula officinalis leaves and stalks, after irradiation of germinated seeds. The germinated seeds of Calendula officinalis has been irradiated at 8 different doses ( 1 k Rad, 3 k Rad, 5 k Rad, 10 k Rad, 20 k Rad, 50 k Rad, 100 k Rad, 500 krad), one set of seeds remaining unirradiated for comparison. The plants had been grown in the same conditions of light, temperature and humidity. The identification of beta-carotene was performed through thin layer chromatography. The chemical concentrations of beta-carotene, chlorophyll a and b were determined by spectral difference method. (authors)

Effect of preoperative irradiation on healing of low colorectal anastomoses

International Nuclear Information System (INIS)

Morgenstern, L.; Sanders, G.; Wahlstrom, E.; Yadegar, J.; Amodeo, P.

1984-01-01

The effect of preoperative irradiation on the healing of low colorectal anastomoses was studied experimentally. In 12 dogs in whom preoperative irradiation of 4,000 rads was given before low colorectal stapled anastomosis was performed, anastomotic leakage occurred in 66 percent. More than half of the anastomotic leaks were associated with either severe sepsis or death. In a matched group of control animals that underwent stapled anastomoses without irradiation, no anastomotic complications occurred. The clinical implications of this study are that stapled anastomoses in irradiated colon are at serious risk of anastomotic dehiscence and, therefore, should be protected with a proximal colostomy

Irradiation effects on the tumor and adjacent tissues of brain tumor-bearing mice

International Nuclear Information System (INIS)

Yoshii, Yoshihiko; Maki, Yutaka; Tsunemoto, Hiroshi; Koike, Sachiko; Furukawa, Shigeo.

1979-01-01

C 3 H mice aged 56 - 70 days, weighing 27 - 37 g were used throughout this experiment. A transplantable fibrosarcoma arising spontaneously from C 3 H mice was used. For experiment, 10 4 tumor cells suspended in 0.025 ml of saline solution were injected into the cerebral hemisphere by a 26 gauge needle with a micrometer syringe under nembutal anesthesia. Whole brain irradiation was performed at 7 days after injection of the tumor cells and the radiation doses were 2,000 and 20,000 rads, respectively. The feature of x-rays were 200 kVp, 20 mA, 0.5 mm Cu + 0.5 mm Al filtration and TSD 20 cm. The dose-rate was 340 - 360 R/min. The articles of this study were as follows: a) Determination of LD 50 values for the mice, tumor-bearing in the brain or non-tumor-bearing; and b) Observation of clinical features and gross autopsy findings of the mice following irradiation. The LD 50 values for 2,000 rad irradiation in the tumor-bearing or non-tumor-bearing mice were 10.9 and 11.4 days, respectively. LD 50 values of 3.7 days and 4.3 days were the results for the tumor-bearing and non-tumor-bearing mice irradiated by 20,000 rad, respectively. On the other hand, the LD 50 value for the control group, i.e. non-irradiated mice, was 6.7 days. At postmortem examinations, gastrointestinal bleeding was observed frequently in mice bearing tumor in the brain. Whole brain irradiation is effective to prolong the life of tumor-bearing mice. However, in some instances, deaths have occurred earlier in tumor-bearing mice compared to the control group. (author)

Physical mapping and cloning of RAD56

DEFF Research Database (Denmark)

Mathiasen, David P; Gallina, Irene; Germann, Susanne Manuela

2013-01-01

Here we report the physical mapping of the rad56-1 mutation to the NAT3 gene, which encodes the catalytic subunit of the NatB N-terminal acetyltransferase in Saccharomyces cerevisiae. Mutation of RAD56 causes sensitivity to X-rays, methyl methanesulfonate, zeocin, camptothecin and hydroxyurea...

Irradiation for progressive paraparesis in β-thalassemia intermedia

International Nuclear Information System (INIS)

Wilson, J.J.; Hill, M.E.; Crookston, J.H.

1980-01-01

This article describes the case history of a patient suffering from β-thalassemia intermedia. The patient was treated with radiation to the thoraic spine (1500 rad in 5 days) and his condition improved. Subsequent tomography indicated the success of this type of irradiation without recourse to laminectomy. (T.I.)

RAD51B in Familial Breast Cancer

DEFF Research Database (Denmark)

Pelttari, Liisa M; Khan, Sofia; Vuorela, Mikko

2016-01-01

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition......, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD......51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients...

The effect of gamma irradiation on the lysine content of plants

International Nuclear Information System (INIS)

Benedekne-Lazar, M.

1979-01-01

It has been proved by studies on the physiological effect of ionizing irradiation that in plant metabolism important changes take place. From the endosperm of seven-day-old seedlings 14 C-L-Lysine is transported faster to organs, especially to shoots and its incorporation into protein is also more intensive. The animation of the growth of roots and shoots can be observed on 14-day-old plants grown in water culture. In sand culture a surplus in dry weight can be experienced after 56 days for maize, under the influence of 100 rad. Two soybean varieties (Merit, Clay) responded different to irradiation. The dry weight of the Merit variety was increased significantly by 500 and 1000 rad, whereas that of the Clay variety decreased or did not change significantly. The lysine content of plants changes in the function of growth. In the case of the two maize varieties (Szegedi sarga, KSC 360) treatments with 1000 and 5000 rad resulted in an essential surplus of the total lysine content (46.25 and 31.21%, respectively). The total lysine content of the Merit variety has been increased by about 23.9% and 20.92%, respectively. 5000 rad treatment resulted in a negative correlation (-0.77) in the shoots. The total lysine content of the Clay plants was lower than that of the control. Under the influence of 500 and 1000 rad treatments the total lysine content of the shoots of the Merit variety grown in fields increased to a lesser extent (16.82 and 3.19 respectively) than that of plants grown in a climate room. (author)

Irradiation tests on bitumen and bitumen coated materials; Essais d'irradiation de bitume et d'enrobes bitumineux

Energy Technology Data Exchange (ETDEWEB)

Tabardel-Brian, R.; Rodier, J.; Lefillatre, G. [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

1969-07-01

The use of bitumen as a material for coating high-activity products calls for prior study of the resistance of bitumen to irradiation. After giving briefly the methods of preparation of bitumen- coated products, this report lists the equipment which has been used for carrying out the {beta} and {gamma} irradiations of these products, and gives the analytical results obtained as a function of the dose rates chosen and of the total integrated dose. Finally, some conclusions have been drawn concerning the best types of bitumen. It should be stressed that some bitumens apparently underwent no degradation whatsoever nor any volume increase, for a total integrated dose of 1.8 x 10{sup 10} rads. (authors) [French] Dans le cadre de l'enrobage par le bitume des produits de haute activite, il est necessaire de verifier au prealable, la tenue du bitume a l'irradiation. Apres un bref rappel de la preparation des enrobes bitumineux, le present rapport regroupe les moyens qui ont ete mis en oeuvre, pour effectuer leurs irradiations sous rayonnement {beta} et sous rayonnement {gamma}, ainsi que les resultats des analyses qui ont ete faites en fonction des debits de doses choisis et de la dose totale integree. Enfin, des conclusions ont ete tirees sur les types de bitume a retenir. On peut souligner que certains bitumes n'ont subi aucune degradation apparente ni augmentation de volume pour une dose totale integree de 1.8 x 10{sup 10} rads. (auteurs)

Experimental study of an active specific immunotherapy modified with irradiation, 2

International Nuclear Information System (INIS)

Imanaka, Kazufumi; Ogawa, Yasuhiro; Takashima, Hitoshi

1982-01-01

We had demonstrated in the former investigation that the strongest local infiltration of T-lymphocytes was observed in C3H/He mice transplanted MM46 at seven days after irradiation with the dose of 2,000 rads. This result indicated that the enhancement of the antigenicity of tumor cells was attained after low-dose-irradiation. We had also reported that specific active immunotherapy using low-dose-irradiated tumor cells and activated mononuclear cells after radiotherapy was effective on the elongation of survival period. In this paper, we studied whether the tumor cell inoculated after active specific immunotherapy was inhibited or not. Active specific immunotherapy using tumor cells and mononuclear cells was performed on female C3H/He mice aged 12 weeks in the left hind paws. Tumor cells and mononuclear cells were separated from the tumor tissue on the 12th day since inoculation of 5 x 10 6 of MM46 tumor cells which were irradiated with the dose of 2,000 rads of 3,000 rads by high energy electron beam on the fifth day. Seven days after active specific immunotherapy 1 x 10 5 or 1 x 10 6 of tumor cell were i noculated in the right hind paws of mice which received active specific immunotherapy. Anti-tumor effect was evaluated by the changes of tumor volume and survival rate. The tumor volume of the group which received active specific immunotherapy was smaller than that without active specific immunotherapy for about nine days since inoculation. Fifty-day survival rate was significantly higher in the group which received active specific immunotherapy compared with the group without immunotherapy (p < 0.01). (author)

Mongoose: Creation of a Rad-Hard MIPS R3000

Science.gov (United States)

Lincoln, Dan; Smith, Brian

1993-01-01

This paper describes the development of a 32 Bit, full MIPS R3000 code-compatible Rad-Hard CPU, code named Mongoose. Mongoose progressed from contract award, through the design cycle, to operational silicon in 12 months to meet a space mission for NASA. The goal was the creation of a fully static device capable of operation to the maximum Mil-883 derated speed, worst-case post-rad exposure with full operational integrity. This included consideration of features for functional enhancements relating to mission compatibility and removal of commercial practices not supported by Rad-Hard technology. 'Mongoose' developed from an evolution of LSI Logic's MIPS-I embedded processor, LR33000, code named Cobra, to its Rad-Hard 'equivalent', Mongoose. The term 'equivalent' is used to infer that the core of the processor is functionally identical, allowing the same use and optimizations of the MIPS-I Instruction Set software tool suite for compilation, software program trace, etc. This activity was started in September of 1991 under a contract from NASA-Goddard Space Flight Center (GSFC)-Flight Data Systems. The approach affected a teaming of NASA-GSFC for program development, LSI Logic for system and ASIC design coupled with the Rad-Hard process technology, and Harris (GASD) for Rad-Hard microprocessor design expertise. The program culminated with the generation of Rad-Hard Mongoose prototypes one year later.

Renal effects of renal x irradiation and induced autoallergic glomerulonephritis

International Nuclear Information System (INIS)

Rappaport, D.S.; Casarett, G.W.

1979-01-01

This study was conducted to determine what influence a single large x-ray exposure of kidney has on the development and course of an experimental autoallergic glomerulonephritis (EAG) in rats. EAG was induced in female Sprague-Dawley rats by immunization with Bordetella pertussis vaccine and homogenate of homologous kidney tissue and Freund's complete adjuvant. Progressive arteriolonephrosclerosis (ANS) was observed in right (irradiated) kidneys following unilateral renal irradiation (1500 rad). Rats were either immunized, sham-immunized, irradiated, sham-irradiated, or both immunized and irradiated. Light and immunofluorescent microscopic observation, urine protein content, and kidney weights were evaluated. In immunized-irradiated animals the effects of irradiation and immunization were largely additive. Immunization did not considerably influence the development and course of ANS and irradiation did not considerably influence the development and course of EAG

On kinetic study of blood cells and bone marrow under fractionated irradiation

International Nuclear Information System (INIS)

Teterina, V.I.

1977-01-01

To study the changes in the cellular composition of bone marrow during irradiation experiments on the guinea pigs have been carried out. Animals were subjected to fractionated irradiation; daily dose of 12 rad, total doses of 250, 500, 750, 1000 and 1500 rad, total duration of radiation of 1,2,3,4 and 6 monts. Experiments have shown that with small levels of total doses of the ionizing radiation haemopoiesis in the bone marrow reached its maximum. This led to suppression of anaemia and profound leukaemia in the peripheral blood. With the increase of total doses phase of insufficient compensation of harmful effects of radiation has been reached, which with continuing radiation may lead to the exhaustion of reserve possibilities of bone marrow and to the development of pancytopenia

Recruitment kinetics of DNA repair proteins Mdc1 and Rad52 but not 53BP1 depend on damage complexity.

Directory of Open Access Journals (Sweden)

Volker Hable

Full Text Available The recruitment kinetics of double-strand break (DSB signaling and repair proteins Mdc1, 53BP1 and Rad52 into radiation-induced foci was studied by live-cell fluorescence microscopy after ion microirradiation. To investigate the influence of damage density and complexity on recruitment kinetics, which cannot be done by UV laser irradiation used in former studies, we utilized 43 MeV carbon ions with high linear energy transfer per ion (LET = 370 keV/µm to create a large fraction of clustered DSBs, thus forming complex DNA damage, and 20 MeV protons with low LET (LET = 2.6 keV/µm to create mainly isolated DSBs. Kinetics for all three proteins was characterized by a time lag period T(0 after irradiation, during which no foci are formed. Subsequently, the proteins accumulate into foci with characteristic mean recruitment times τ(1. Mdc1 accumulates faster (T(0 = 17 ± 2 s, τ(1 = 98 ± 11 s than 53BP1 (T(0 = 77 ± 7 s, τ(1 = 310 ± 60 s after high LET irradiation. However, recruitment of Mdc1 slows down (T(0 = 73 ± 16 s, τ(1 = 1050 ± 270 s after low LET irradiation. The recruitment kinetics of Rad52 is slower than that of Mdc1, but exhibits the same dependence on LET. In contrast, the mean recruitment time τ(1 of 53BP1 remains almost constant when varying LET. Comparison to literature data on Mdc1 recruitment after UV laser irradiation shows that this rather resembles recruitment after high than low LET ionizing radiation. So this work shows that damage quality has a large influence on repair processes and has to be considered when comparing different studies.

Post-irradiation abortion: a slaughter of innocents

International Nuclear Information System (INIS)

Dalrymple, G.V.; Baker, M.L.

1977-01-01

The medical profession and the lay public have not been overly concerned about the effects of diagnostic x-rays or radioactive isotopes until the last decade when radiation was rediscovered to cause damage to the fetus. In addition, radiation is associated with increased incidence of childhood cancer as well as chromosome damage and related birth defects. While some fear of radiation during the embryonic-fetal period, one of great radiosensitivity, is justified, the anxiety has been intensified by the attitudes of some physicians. Instances have occurred in which a patient who had received a very small amount of radiation (from diagnostic x-ray examination) was advised to have an abortion. A foreseeable result of such events has been litigation against involved physicians. Counter-measures that have been suggested are: do not irradiate women known to be pregnant without a firm clinical indication; if accidental iradiation is discovered the actual dose to the fetus should be estimated. Usual diagnostic examination will give fewer than 5 rads to the fetus and such doses do not represent grounds for abortion. For doses of 5-10 rads abortion could be considered and above 10 rads there would be stronger consideration for such a recommendation. other factors to be considered include age of the mother, and environmental factors (medicines, food additives, cigarettes, coffee, etc.). Proper radiologic practice will eliminate or reduce the number of pregnant women irradiated

The effect of steroids on experimental brain edema induced by irradiation

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, M [Kobe Univ. (Japan). School of Medicine; Kakei, M

1975-04-01

In order to study the effect of steroids on brain edema, complicated by radiotherapy to brain tumors, an experiment was carried out in rats. Five thousand rads of cobalt-60 were irradiated to the head only of a rat, and 20 mg/kg of water-soluble prednine was given intraperitoneally. A single administration of the whole dose increased the amount of brain fluid to 79.35 +- 0.30 g/ 100 g wet wt.. This value was not significantly different from that of the rat which had received only the 5,000 rad irradiation. In a rat which received prednine in 6 divided doses at intervals of 4 hours, the fluid amount reached 78.33 +- 0.52 g/ 100 g wet wt. and was clearly lower than that of the rat which had been irradiated only, 79.51 +- 0.23 g/ 100 g wet wt. neither was the value significantly different from that of a normal rat which had not been exposed 78.72 +- 0.82 g/ 100 g wet wt.. Therefore, fractional administration of prednine was demonstrated to be effective.

Effects of high-dose and low-dose preoperative irradiation on low anterior anastomoses in dogs

International Nuclear Information System (INIS)

Bubrick, M.P.; Rolfsmeyer, E.S.; Schauer, R.M.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Hitchcock, C.R.

1982-01-01

Twenty mongrel dogs underwent preoperative irradiation to the colon and rectum, receiving 4000 rads according to the Nominal Standard Dose Equation. Each dog then underwent anterior resection of the rectosigmoid, and reconstructive technique was randomized into two groups consisting of either handsewn or EEA-stapled anastomoses. Anastomoses were examined digitally and radiographically at the time of surgery and on the seventh postoperative day. There were four radiographic leaks among the handsewn anastomoses, but only one was clinically significant and associated with peritonitis. There were no leaks among the ten EEA-stapled anastomoses. The data suggest that low anterior resection and anastomosis can be done safely after 4000 rad irradiation and that the EEA-stapled anastomosis may be preferable

Effects of high-dose and low-dose preoperative irradiation on low anterior anastomoses in dogs

Energy Technology Data Exchange (ETDEWEB)

Bubrick, M.P.; Rolfsmeyer, E.S.; Schauer, R.M.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Hitchcock, C.R.

Twenty mongrel dogs underwent preoperative irradiation to the colon and rectum, receiving 4000 rads according to the Nominal Standard Dose Equation. Each dog then underwent anterior resection of the rectosigmoid, and reconstructive technique was randomized into two groups consisting of either handsewn or EEA-stapled anastomoses. Anastomoses were examined digitally and radiographically at the time of surgery and on the seventh postoperative day. There were four radiographic leaks among the handsewn anastomoses, but only one was clinically significant and associated with peritonitis. There were no leaks among the ten EEA-stapled anastomoses. The data suggest that low anterior resection and anastomosis can be done safely after 4000 rad irradiation and that the EEA-stapled anastomosis may be preferable.

Brain sarcoma of meningeal origin after cranial irradiation in childhood acute lymphocytic leukemia. Case report

International Nuclear Information System (INIS)

Tiberin, P.; Maor, E.; Zaizov, R.; Cohen, I.J.; Hirsch, M.; Yosefovich, T.; Ronen, J.; Goldstein, J.

1984-01-01

The authors report their experience with an unusual case of intracerebral sarcoma of meningeal cell origin in an 8 1/2-year-old girl. This tumor occurred 6 1/2 years after cranial irradiation at relatively low dosage (2200 rads) had been delivered to the head in the course of a multimodality treatment for acute lymphocytic leukemia. The tumor recurred approximately 10 months after the first surgical intervention. Macroscopic total excision of the recurrent growth followed by whole-brain irradiation (4500 rads) failed to eradicate it completely and local recurrence prompted reoperation 18 months later. This complication of treatment in long-term childhood leukemia survivors is briefly discussed, as well as the pathology of meningeal sarcomas

The effect of local irradiation on the immune response in mice. I. Effect of sham-irradiation

International Nuclear Information System (INIS)

Gauci, C.L.; Gerber, M.; Dubois, J.-B.; Serrou, B.

1979-01-01

In C57BL/6 mice exposed to 1600 rads to the left foot pad, an important decrease of non-specific inflammatory responsiveness initiated by the injection of oyster glycogen into the peritoneal cavity was observed on the one hand and a diminution of the delayed hypersensitivity response following tuberculin injection, on the other hand. Nevertheless, the same immunosuppression was noted both in sham irradiated mice and in those receiving hydrocortisone. In irradiated mice this transient immunosuppression was related to a normal adrenal function. Bi-laterally adrenalectomised mice did not exhibit this reaction which reappeared after hydrocortisone administration. The reduction of delayed hypersensitivity is irrespective of the irradiated zone, but the duration of immune depression is longer in irradiated than in unirradiated tissue. During the depression of delayed hypersensitivity response an increase in the number of splenic B-lymphocytes and macrophages and a decrease of the number of splenic T-lymphocytes was observed these observations suggest that immunosuppression following irradiation is related to acute stress

A study of the behaviour of irradiated or unirradiated grafts in the camera aquosa of irradiated and unirradiated animals; Etude du comportement d'un greffon irradie ou non, transplante dans la chambre anterieure de l'oeil d'un animal irradie ou non

Energy Technology Data Exchange (ETDEWEB)

Djalali-Behzad, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-06-01

Following grafts of new born mice spinal ganglia in the 'camera aquosa' of adult mice, the authors tried hematopoietic tissue grafts in the same conditions. The growth of iso-logous and hetero-logous bone marrow in the 'camera aquosa' showed that this tissue, even after exposure to supralethal doses, was capable of survival and growth. A counter-experiment with non irradiated bone marrow grafts in the 'camera aquosa' of rats delivered 700 rads led to the conclusion that the environment, intoxicated by exposure, acted on the graft so that after vascularization it became unable to grow. (author) [French] Apres avoir greffe des ganglions rachidiens de souriceaux nouveaux-nes dans la chambre anterieure de l'oeil de souris adultes, l'auteur a tente de greffer du tissu hematopoietique de la meme facon. La proliferation de la moelle osseuse isologue et heterologue, dans la chambre anterieure de l'oeil, lui a permis de mettre en evidence une certaine capacite de survie et de proliferation de ce tissu irradie meme a dose supraletale. Par une contre-experimentation, c'est-a-dire par la greffe de moelle non irradiee dans la chambre anterieure de rats irradies a 700 rads, il conclut que le milieu ambiant, intoxique par l'irradiation, agit sur le greffon de telle sorte que ce dernier, apres s'etre vascularise, devient depourvu de son aptitude de proliferation. (auteur)

Irradiation and study of irradiated full elements and sintered UO{sub 2} fuel; Ozracivanje i ispitivanje ozracenih gorivnih elemenata i goriva na bazi sinterovanog UO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Stevanovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

1966-11-15

This review contains the activities related to the development of UO{sub 2} fuel elements, based on study of the processes in the fuel. This work was done during development, irradiation and testing of certain type of fuel rods and fuel assemblies. A feasibility study for irradiation of fuel elements in our country or abroad was done by analysing the defined problem and our capabilities in this field. Izlozen je pregled potrebnih radova na ozracivanju vezanih za razvoj gorivnih elemenata sa UO{sub 2} gorivom, prikazan kroz rad na osnovnim usmerenim istrazivanjima procesa i pojave u gorivu, kroz razvoj odredjenog tipa gorivnih elemenata ozracivanjem i ispitivanjem ozracenih gorivnih sipki i sklopova gorivnih elemenata. Na osnovu tako postavljenog problema i nasih mogucnosti za rad na ovom polju izvrsena je analiza celishodnosti ozracivanja gorivnih elemenata (goriva) kod nas, odnosno u inostranstvu (author)

Evidence for interphase death in irradiated primate salivary glands