[en] Los Alamos County (LAC) is home to the Los Alamos National Laboratory, a U.S. Department of Energy (DOE) nuclear research and design facility. In 1991, the DOE funded the New Mexico Department of Health to conduct a review of cancer incidence rates in LAC in response to citizen concerns over what was perceived as a large excess of brain tumors and a possible relationship to radiological contaminants from the Laboratory. The study found no unusual or alarming pattern in the incidence of brain cancer, however, a fourfold excess of thyroid cancer was observed during the late-1980's. A rapid review of the medical records for cases diagnosed between 1986 and 1990 failed to demonstrate that the thyroid cancer excess had resulted from enhanced detection. Surveillance activities subsequently undertaken to monitor the trend revealed that the excess persisted into 1993. A feasibility assessment of further studies was made, and ultimately, an investigation was conducted to document the epidemiologic characteristics of the excess in detail and to explore possible causes through a case-series records review. Findings from the investigation are the subject of this report

[en] Physical distance can play an important role in the process leading to the translocations that are responsible for oncogenic transformation of cells. Thus, e.g., one of the reasons of a high incidence of ABL/BCR fusion may be the physical closeness of ABL and BCR genes in cells. The average distance of ABL-BCR genes in interphase lymphocytes is only 24% of the nuclear radius; after stimulation, this distance increases to 35%. The mean value for randomly distributed genes in a sphere is 43%. This means that the mutual distance of the critical genes is largely smaller than the random distance. The distance between chromosomes 9 and 22 in prometaphase plates (rosettes) of human fibroblasts was also investigated. In many prometaphase rosettes, each copy of chromosome 9 was located near a copy of chromosome 22 and the pairs were located on opposite sides of the plate. Thus both in the interphase and in mitosis, the distance between ABL and BCR genes, located in chromosomes 9 and 22, is substantially shorter than the random value. This contributes to the observed incidence of leukemia. The positions of ABL and BCR genes in irradiated and stimulated lymphocytes are shifted to the centre of the nucleus. They are closer to each other, and also the distances between heterologous ABL and BCR genes are shorter. In 15% of the cell nuclei irradiated with gamma rays (5 Gy), the volume in which the genes appear is 6 times smaller than in control nuclei. Hence, the probability of interaction between ABL and CBR genes increases 6² x 0.15 = 5.4 times. Thus, radiation increases substantially the probability of induction of leukemia not only through DNA damage but also due to changes in the chromatin structure in irradiated cells, which concentrates the critical genes in a relatively small volume

[en] The genome radiosensitivity of persons working in the NPP 'Kozloduy', as well as controls are studied. An indicator of genome radiosensitivity is the chromosomal damage induced by in vitro irradiation. A cytogenetic analysis of peripheral blood lymphocytes before and after in vitro irradiation with a dose of 1.5 Gy gamma rays is carried out. The frequency of chromosomal aberrations and micronuclei before and after the irradiation is scored. In certain cases the technique of fluorescent in situ hybridization for recording stable chromosome rearrangements is applied. The data obtained show a decreased chromosome radiosensitivity in occupationally engaged persons as compared to low doses, over a long period of time, may induce the so called 'adaptive response' which makes cells more resistant of subsequent in vitro irradiation with a high dose (author)

[en] This is a report on changes in the conformation of protein macromolecules in blood plasma and the correlation of conformational data with biological activity of the irradiated human organism. A total of 250 individuals were examined, working in sphere of ionizing radiations and submitted to the action of other nonionizing factors of the occupational environment. The length of service of the individuals examined varied from 1 to 30 years, while the age limits are from 18 to 66 years. The biological activity of protein macromolecules is directly related to its conformation and high frequency characteristics of the dielectric parameters of the blood plasma (high frequency dielectric constant and electro-conductivity). The high frequency dielectric characteristics was measured with Admittance Test type SWM-2, and high frequency generator and Oscilloscope type E01/76. On the basis of data from the measurement of high-frequency dielectric macromolecules and Debay constant were calculated. The obtained results revealed that the combined action of the factors of the occupational environment with ionizing and nonionizing nature induced a denser globalization of the protein macromolecules in the blood plasma and reduced their reaction activity, as compared to the control group. Any radiation and non-radiation induced alteration, produced directly or indirectly in the normal base sequence of macromolecule, constitutes a damage of confirmation, which may or may not be immediately expressed. These effects may become apparent after a variable latent period (author)

[en] A computer code, HEINPUT, has been developed for estimating the late somatic effects and genetic effects induced by radiation exposure in nuclear reactor accidents. HEINPUT is designed as a preprocessor code for the OSCAAR computer code system that has been developed for the accident consequence assessment of nuclear power plants in the probabilistic safety assessment (PSA). The models used in HEINPUT are based upon the health effects models in the NUREG/CR-4214 report titled by 'Health Effects Models for Nuclear Power Plant Accident Consequence Analysis' prepared for U.S. Nuclear Regulatory Commission. These models are revised on the basis of the new information on risk estimates by the reassessment of the radiation dosimetry in Hiroshima and Nagasaki. This report provides a brief description of the methods for estimating both late somatic effects and genetic effects, and a computer code manual that includes the structure of HEINPUT, data libraries, input and output data, and a sample calculation. (author)

[en] The COG project 2806A (1995), reviewed the On-line Mendelian Inheritance in Man (OMIM) database of genetic syndromes to identify those syndromes, genes, and DNA sequences implicated in some way in the cancer process, and especially in radiogenic cancer risk. The current report describes a recent update of the survey in light of two years of further progress in the Human Genome project, and is intended to supply a comprehensive list of those genetic syndromes, genes, DNA sequences and map locations that define genes likely to be involved in cancer risk. Of the 8203 syndromes in OMIM in 1997 June, 814 are associated, even if marginally, with cancer. Of the 814 syndromes so linked, 672 have been mapped to a chromosome, and 476 have been mapped to a chromosome and had a DNA sequence associated with their messenger RNA (or cDNA) sequences. In addition, 35 syndromes have sequences not associated with map locations, and the remaining 107 have neither been mapped nor sequenced. We supply the list of the various genetic syndromes sorted by chromosome location and by OMIM descriptor, together with all the associated but unmapped and unsequenced syndromes. (author)

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