タグ「prenatal」
Title: X-rays induce distinct patterns of somatic mutation in fetal versus adult hematopoietic cells
Author: Li Liang, Li Deng, Marc S. Mendonca, Yanping Chen, Betty Zheng, Peter J. Stambrook, Changshun Shao, Jay A. Tischfield
Reference: DNA Repair, Volume 6, Issue 9, 1 September 2007, Pages 1380–1385
DOI: http://dx.doi.org/10.1016/j.dnarep.2007.04.005
Keywords: Ionizing radiation; Prenatal exposure; Mitotic recombination; Base excision repair; Developmental stage
Abstract: There are a variety of mechanisms and pathways whereby cells safeguard their genomes in the face of environmental insults that damage DNA. Whether each of these pathways is equally robust at specific developmental stages in mammals and whether they are also modulated in a tissue-specific manner, however, are unclear. Here, we report that ionizing radiation (IR) produces different types of somatic mutations in fetal cells compared with adult cells of the same lineage. While 1 Gy of X-ray significantly induced intragenic point mutations in T cells of adult mice, no point mutational effect was observed when applied to fetuses. Fetal exposure to IR, on the other hand, led to a significant elevation of mitotic recombination in T cells, which was not observed in adults. Base excision repair (BER) activity was significantly lower in fetal hematopoietic cells than in adult cells, due to a low level of DNA polymerase β, the rate-limiting enzyme in BER. In fetal hematopoietic cells, this low BER activity, together with a high rate of proliferation, causes X-ray-induced DNA lesions, such as base damage, single strand breaks and double strand breaks, to be repaired by homologous recombination, which we observe as mitotic recombination. Higher BER activity and a relatively lower rate of cell proliferation likely contribute to the significant induction of DNA point mutations in adults. Thus, the mutational response to IR is at least partly determined by the availability of specific repair pathways and other developmentally regulated phenotypes, such as mitotic index.
ＵＲＬ：http://www.sciencedirect.com/science/article/pii/S1568786407001693
Title: Neurobehavioral and Cognitive Performances of Children Exposed to Low-Dose Radiation in the Chernobyl Accident -The Israeli Chernobyl Health Effects Study
Author: N. Bar Joseph, D. Reisfeld, E. Tirosh, Z. Silman and G. Rennert
Reference: Am. J. Epidemiol. (2004) 160 (5): 453-459
doi: 10.1093/aje/kwh231
Keywords: accidents, radiation; child; cognition; health; neurobehavioral manifestations; radiation
Abstract: Exposure to low levels of ionizing radiation after the Chernobyl accident in the Ukraine could potentially have influenced the neurobehavioral and cognitive performances of exposed children. A cohort study of adolescents who were children at the time of the accident and who subsequently emigrated to Israel was conducted in 1998–2001. A total of 1,629 children (59% of all 2,769 invited) were included in the study (41% from higher contamination areas, 25% from lower contamination areas, 34% from noncontaminated areas). Mean scores of the Raven Standard Progressive Matrices Test were highest in children in all exposure groups whose parents had a high level of education. No overall relation was found between the cognitive function scores of the child and his/her putative radiation exposure level. Conners’ test T scores did not differ significantly by level of exposure. Mothers of all exposure groups who were pregnant at the time of the accident gave their children significantly higher Conners’ test scores than did those who were not pregnant. Scores for hyperactivity and attention-deficit/hyperactivity disorder were significantly higher among those who were in utero at the time of the accident. These results do not show differences of neurobehavioral or cognitive performance in exposed versus nonexposed children. There is a possible behavioral effect among offspring of pregnant mothers or mothers of very young children in all exposure levels.
URL: http://aje.oxfordjournals.org/content/160/5/453.long
Author: Loganovsky KN, Loganovskaja TK, Nechayev SY, Antipchuk YY, Bomko MA.
Reference: J. Neuropsychiatry Clin Neurosci. 2008, 20 (3): 274–291.
Keywords:EEG patterns, children, mothers, WISC
Abstract: One hundred children, exposed prenatally to radiation after the Chernobyl nuclear power plant accident, and 50 non-exposed classmates were examined between the ages of 11 and 13 years old using neuropsychiatric tests, WISC, EEG, and visual evoked potentials. Individual prenatal radiation doses were reconstructed for all examined children. The exposed children were found to have more neuropsychiatric disorders, left-brain neurological signs, lower full-scale and verbal IQ, IQ discrepancies with verbal decrement, disorganized EEG patterns, an excess of lateralized-to-left frontotemporal region delta and beta power with depression of theta and alpha power, and interhemispheric inversion visual information processing. Mothers’ mental health, stress, and prenatal irradiation contributed to these effects, along with several confounding factors. (full text in English available on web.)
URL: http://neuro.psychiatryonline.org/article.aspx?articleID=103418
Author: A.I. Nyagu, K.N. Loganovsky, T.K. Loganovskaja et al.
Reference: KURRI-KR-79. — Recent Research Activities about the Chernobyl NPP Accident in Belarus, Ukraine and Russia / T. Imanaka (Ed.). — Kyoto: Research Reactor Institute, Kyoto University, 2002. — P. 202–230
Keywords: neurophysiology, neuropsychiatry, prenatal exposure, behavioral and emotional disorders
Abstract: The objective of the study was psychometric, neurophysiological and neuropsychiatric characterisation of acutely prenatally irradiated children. 100 randomly selected children who were in utero (born between April 26th, 1986 and February 26th, 1987) at the time of the Chernobyl accident and their mothers evacuated to Kiev as well as 100 classmates of the children were examined by the Wechsler Intelligence Scale for Children (WISC), electroencephalography (EEG) and clinical methods at the age of 10–12 years old. Foetal doses in the acutely exposed group were 11–92 mSv, in the comparison group — 0–3 mSv; foetal thyroid doses — 0.2–2 Gy and 0–0.04 Gy, respectively. The acutely exposed group showed a lower mean verbal IQ than in the comparison group (105.3±13.1 vs.118.1±13; p < .001) and a lower mean full scale IQ (112.1±15.4 vs. 120.9±11.5; p < .001). In addition the followings were observed in the acutely exposed group; WISC performance/verbal discrepancies with verbal decrements; a higher frequency of low-voltage and epileptiformal EEG-patterns and left hemisphere lateralised dysfunction; an increase (p < .001) of δ- and β-power and a decrease (p < .001) of θ- and α-power; an increased frequency of paroxysmal and organic mental disorders, somatoform autonomic dysfunction, disorders of psychological development, and behavioural and emotional disorders. Cerebral dysfunction was etiologically heterogeneous. This study suggests that prenatal irradiation at a thyroid foetal dose range of 0.2–2 Gy and a foetal dose of 11–92 mSv can result in detectable brain damage.
URL: http://www.rri.kyoto-u.ac.jp/NSRG/reports/kr79/KURRI-KR-79.htm
Author: S. Bazyltchik, V.M. Drozd, Chr. Reiners, Yu. Gavrilin
Reference: International Journal of Radiation Medicine. — 2001. — Special Issue 3, № 1–2. — P. 15.
Reference: — Amsterdam: Elsevier (Pergamon), 2003. — 230 p.
Keywords: pre-implantation, organogenesis, and fetogenesis, animal study
Abstract: 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.
URL: http://www.icrp.org/publication.asp?id=ICRP%20Publication%2090
Reference: Directorate-General Environment, Nuclear Safety, and Civil Protection, 1998. — 30 p.
Abstract: Whole article in English available on web.
URL: http://ec.europa.eu/energy/nuclear/radiation_protection/doc/publication/100_en.pdf
Author: A.I. Nyagu, K.N. Loganovsky, R. Pott-Born et al.
Reference: International Journal of Radiation Medicine. — 2004. — Vol. 6, № 1–4. — P. 91–107.
Keywords: Chernobyl accident, brain damage in utero, dosimetry, psychometry, neuropsychiatric and psychological disorders.
Abstract: One of the grave consequences of the Chernobyl accident was the in utero irradiation of children. It was therefore important to study possible effects of prenatal irradiation resulted from the Chernobyl accident on neuromental health of the in utero irradiated children. A cohort of 154 children born between April 26th,1986 and February 26th,1987 to mothers who had been evacuated from Prypiat to Kiev,and 143 classmates from Kiev were examined. The Wechsler Intelligence Scale for Children (WISC),the Achenbach and Rutter A(2) tests were used for the children. School performance was also assessed. Mothers were examined with the verbal subscale of the Wechsler Adults Intelligence Scale (WAIS),the Zung Self-Rating Depression Scale (SDS),PTSD scales (Impact of Events Scale and Irritability,Depression,Anxiety Scales) and the General Health Questionnaire (GHQ-28). Neuropsychiatric diseases were diagnosed according to ICD-10. Individual dose reconstruction of the children exposed in utero was carried out considering internal and external exposure. The ICRP Publication-88 was applied for calculation of effective fetal, brain and thyroid internal doses for children of both groups. The mean effective fetal equivalent doses (M±SD) in the exposed group is 65.4±33.9 mSv and in the control group 1.2±0.3 mSv. 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 in total doses >100 mSv and there were 52 children from Pripyat town (33.8%) 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. Significant differences on intelligence and emotional and behavioral
disorders of exposed children in comparison to the control group were revealed….
URL: http://www.mns.gov.ua/files/rm/PDF/6_15.pdf
Author: K.S. Heiervang, S. Mednick, K. Sundet, B.R. Rund
Reference: Scand. J. Psychol. — 2010. — Vol. 51, № 3. — 210–215.
Keywords: Norway, IQ, prenatal exposure
Abstract: Radiation from the Chernobyl nuclear power plant meltdown greatly affected several Norwegian counties. The cognitive consequences of in utero exposure to radiation from the Chernobyl accident have been intensely debated. This study examines the cognitive outcomes for those Norwegians who were exposed as fetuses to the fallout from Chernobyl. The participants, 84 adolescents who were exposed in utero to radiation from the most contaminated areas in Norway and 94 adolescents from areas not contaminated by the radiation, were tested on verbal and nonverbal IQ. Two data analyses were conducted. First, using a control-group design, the IQ scores of exposed and unexposed adolescents were compared. Second, in a timing-of-exposure design, those exposed during the most sensitive period were contrasted with those exposed later in gestation. Adolescents exposed to low-dose ionizing radiation in utero scored significantly lower in full-scale IQ than unexposed adolescents. The difference was restricted to verbal IQ and was not evident for nonverbal IQ. The effect was not observed in exposed adolescents who had passed the most sensitive gestational period prior to the accident and thus were exposed to the radiation from Chernobyl exclusively after gestational week 16. These participants performed as well as the controls. Although the results should be interpreted cautiously due to the study’s nonrandomized design, the data add new and important support to the hypothesis that the Chernobyl accident may have had a subtle effect on the cognitive functioning of those exposed to low-dose ionizing radiation in utero during the most sensitive gestational period.
URL: http://www.ncbi.nlm.nih.gov/pubmed/20338021
M. Hatch, A. Brenner, T. Bogdanova et al.
URL: http://www.ncbi.nlm.nih.gov/pubmed/19106267
