Radiation databases and archives - examples and comparisons

Abstract

Studies of ionizing radiation effects through the archiving of data began with standardizing medical treatments in the early 1900s shortly after the discovery of X-rays. Once the breadth of the delayed effects of ionizing radiation was recognized, the need for long-term follow up became apparent. There are now many human archives of data from nuclear disasters and accidents, occupational exposures, and medical procedures. Planned animal irradiation experiments began around the time of the Cold War and included a variety of doses, fractions, dose rates, and types of ionizing radiation. The goal of most of these studies was to supplement information coming from human data through carefully planned experimental conditions and immediate and uninterrupted data collection. This review aims to highlight major archives and databases that have shaped the field of radiation biology and provide a broad range of the types of datasets currently available. By preserving all of these data and tissue sets, radiation biologists can combine databases and conduct large-scale analyses of detailed existing data and perform new assays with cutting edge scientific approaches.

Keywords: Ionizing radiation; archive; database; historical data.

Figure 1.

Schematic representation of the history of the most important radiation data archives, with some of the examples highlighted in this paper. Immediately after the discovery of X-rays, medical professionals in radiation began suffering from skin carcinomas. Further evidence of the risks associated with ionizing radiation accumulated from radiation workers and patients that received radiotherapy, but these results were not widely known (Miller 1995). After the atomic bombings in 1945, the first sign of delayed effects of ionizing radiation was occurrence of cataracts and soon after leukemia among the survivors. High numbers of individuals affected assured wide distribution of this knowledge. This sparked the initiation of long-term follow up of subjects exposed to ionizing radiation in all nuclear disasters. The unknown long-term effects of ionizing radiation combined with the threat of additional nuclear bombings inspired many large-scale planned animal experiments. Cubed lines indicate exposure periods and a rhombus symbol indicates the time of a single event.

Figure 2.

Transmission electron micrographs of liver sample harvested from a beagle dog chronically exposed to external beam gamma-rays, total dose of 30Gy (dose rate of 130 mGy per day for 236 days), beginning at day 462 after birth. Ten such animal exposures were done at Argonne National Laboratory; 70% of these dogs died of fatal tumors; their median survival was 10.6 years. This specific animal (ID 1971) had several neoplastic diseases at the time it became moribund: malignant sarcoma of the liver, metastatic undifferentiated thyroid carcinoma, malignant spleen sarcoma as well as benign spleen hemangioendothelioma and benign testicular tubular androblastoma. In addition, several serious non-tumor complications were found at necropsy. Left panel (magnification 9,000) shows several liver cells (N=nucleus, L=lysosome, m= mitochondria, v= autophagic vesicles), right panel (magnification 75,000) shows autophagic vesicles (v); dashed white oval encircles a mitochondria undergoing mitophagy. At the time when this image was obtained mitophagy had not yet been described, nor its dual role in maintenance of cellular health as well as resistance of cancer cells to therapy.