Long-term follow-up of the genital organs and eye lenses in three cases of acute radiation sickness from a 60Co radiation accident in China.

A follow-up study aimed primarily at investigating late radiation effects on the genital organs and eye lenses was performed between 1999 and 2010 on three individuals who suffered from acute radiation sickness in China. The examination included a medical history, a physical examination, ultrasonography, laboratory analysis, and an ophthalmologic examination. In Case 1, amenorrhea occurred after exposure to a Co source. The uterus and ovaries were significantly narrowed in the second year following exposure. The estradiol level decreased significantly during the first 3 y; progesterone was lowest in the second year; and levels of follicle-stimulating hormone and luteinizing hormone increased, especially in the first year. The lenses in both eyes appeared opaque 6 mo after the exposure, resulting in a gradual deterioration in visual acuity. In Case 2 (8 y old), the levels of testosterone and estradiol were normal. In Case 3, the levels of testosterone and estradiol were also normal, but the sperm count was 0 from 6 mo to 1 y, and the proportion of abnormal sperm was increased from 3-5 y after the accident. The lenses in Case 3 also began to turn opaque in the ninth year after the accident. In Case 1, the ovarian function was reduced, leading to amenorrhea and early menopause. In Case 3, the sperm count was reduced and the number of abnormal sperm was increased due to testicular damage by radiation. Radiation-induced cataracts occurred in both Case 1 and Case 3.

Cytogenetic analysis of peripheral blood lymphocytes, many years after exposure of workers to low-dose ionizing radiation.

The present study aims to measure chromosomal aberrations and micronuclei in peripheral blood lymphocytes from 25 subjects exposed to 0.10-0.33 Gy external or internal irradiation 32-41 years ago using conventional cytogenetic analysis methods. The frequencies of total chromosome-type aberrations and micronucleus significantly increased in the exposed group compared with that in age-matched control group (p<0.001); chromatid-type aberrations showed no difference between the two groups (p>0.05). When exposed subjects were divided into two groups based on exposure dose, higher levels of dicentric plus translocation frequencies were observed in the ≥0.15 Gy dose group compared with those in the <0.15 Gy dose group, though the difference was not significant. Borderline association between exposure dose and dicentric frequency was detected in the exposed group (r=0.358; p=0.079). These results suggest that the genotoxic effects of ionizing radiation remain in subjects exposed to low-dose radiation even decades after exposure.

Follow-up study by chromosome aberration analysis and micronucleus assays in victims accidentally exposed to 60Co radiation.

The goal of this study was to assess the persistence of chromosomal aberrations and micronuclei of three victims 2 y after accidental radiation exposure to Co gamma rays. Traditional chromosome aberration analysis was performed by scoring the dicentric chromosomes (dic) and rings (r) in peripheral blood lymphocytes. Micronuclei were detected using the cytokinesis block micronucleus assay. G-banding and semi-automatic karyotype analysis was used to record translocations (t), inversions (inv) and deletions (del). The frequency of unstable chromosomal aberrations (dicentrics and rings) remained at high levels 6 mo after the accident. Two years after exposure, the frequency was reduced to 4-11% in the three victims. However, stable chromosome aberrations, which were detected by G-banding and included t, inv, and del, remained at a high level and have an obvious dose-dependent relationship even 2 y post-exposure. The frequency of micronuclei decreased faster than that of chromosome aberrations, reaching almost a normal level two years after the accident, especially for the child victim. Unstable chromosome aberrations reduced gradually, but the stable aberration remained at a high level along with the time-lapse. The micronucleus assay was less valuable for assessing long-term effects after high dose irradiation.

Clinical report of three cases of acute radiation sickness from a (60)Co radiation accident in Henan Province in China.

On 26 April 1999, three persons were accidentally exposed by high dose (60)Co irradiation. They suffered from severe (one case) or moderate (two cases) hemopoietic form of acute radiation sickness (ARS). As part of the comprehensive treatment, strict reverse isolation and granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy were applied. All the patients recovered after an appropriate treatment for 83 days. In our experience, the correct diagnosis and effective treatment at an early stage proved to be helpful to the patients in pulling out from the critical stage of acute radiation sickness. To avoid menstruation by the female patient just in the critical stage, we modified her menstruation cycle by testosterone. In our view, GM-CSF should be given as early as possible with enough dosage for promoting early hematological reconstruction. The experience obtained from the medical management of these patients is valuable for the treatment of such patients in the future.

[Biological dose assessment by the analyses of chromosomal aberrations and CB micronuclei in two victims accidentally exposed to 60Co gamma-rays].

Biological doses were estimated by using the yields of dicentrics plus rings(dic+r) and cytokinesis-block micronuclei (CBMN) for two victims of the accident radiation occurred on Mar 6,2000 in the City of Xuchang(victim A), and Jun 26,2000 in the City of Kaifeng(victim B), Henan Province,respectively. The results indicated that the equvalent whole body doses based on the standard dose-response curves established by the analyses of dic+r and CBMN were estimated to be 1.44Gy and 1.43Gy(victim A), and 0.15Gy and 0.22Gy(victim B). These doses were very consistent with the mean doses calculated from physical measurement and conformable to the clinical dianosis. The dic+r aberrations of victim A did not accord with Poisson distribution. The analyses of chromosomal aberrations and CBMN are an extremely reliable method in biological dosimetry. The radiation which victim A was exposed to was heterogeneous.