Natural history of disease in atomic bomb exposed twins in Hiroshima--findings of chest x-ray and electrocardiogram.

The subjects of this study are mainly pairs of monozygotic twins, one of whom w s exposed to the atomic bomb and the other not exposed, and the natural history of the diseases of these twins was analyzed to find out genetic and environmental factors of the diseases and some biological effect of the atomic bomb exposure or other. In this study, 13 pairs of monozygotic and 5 pairs of dizygotic twins and other 34 cases of non-twins were examined by means of heart and lung X-ray films and electrocardiograms. The results suggest that most of the monozygotic twins show the similar findings of chest X-ray films, though their electrocardiograms have a tendency to deviate to the left in the QRS axis. These findings will not be enough to clear up the relation between the atomic bomb expose::l and the abnormal electrocardiograms. twins. INTRODUCTION MATERIALS AND METHODS 107 The purpose of this study is to make a general medical and genetic investigation on the atomic bomb exposed twins to look for some biological effect of atomic bomb exposure and to provide data that are useful for the health managemant of atomic bomb survivors. Subjects are mainly pairs of monozygotic twins, one of whom was exposed to the atomic bomb and the other not exposed. As for pairs, both of whom were exposed, an investigation is also made to see how they have been affected by the difference of enviromental conditions8>. They will be grouped with the similar findings to make clear the interrelation of environmental fastors including atomic bomb exposure. In this paper, we are going to show the findings of heart and lung X-ray films and electrocardiograms of some pairs of the exposed monoand dizygotic Exposed twins were picked up by an electronic computer from the master file of atomic bomb survivors in our instituts7> and examined clinically and physiologically10 ' 12>. Their zygosity di1gnoses were also made. The natural history of their diseases was investigated to find out possible late effects of the atomic bomb. Am::mg many check-up points, the values of immnoglobulin M and A 1> and the height2> are considered to be genetically controlled to a considerable extent. On the other hand, the values of immnoglobulin G0 , serum cholesterol, body weight, blood pressure316> and electrocardiogram6> are considere::l to be susceptible to both genetic and environmental effects. The concordance or discordance of these values might provi:le an indicator of the genetic and or environ*) {tc)Ji°f!fJ, :Xf!Jftlfl'fr, [P1]/.Js:W:IE, *-fffl ~' mtJllIE~: JJjUifBi~}X1:JC.O):J3a~!3~st:vz:.l*J-t~TVF~-1 C..'. )JifjXff~~ J::: ,c.,,m~m J[vc 01, ,-c ~.