Changes of activity inducing chromosomal aberrations and transformations of chlorinated humic acid.

The change of the toxicity of chlorinated water after chlorine injection was examined. For the measurement of toxicity, chromosomal aberration test and transforming test were carried out as indexes to initiating activity and to promoting activity in the carcinogenesis process, respectively. Activity inducing chromosomal aberrations of chlorinated humic acid gradually decreased with time after chlorination. In contrast, activity inducing transformations measured by the two-stage assay gradually increased. Thus, the toxicity that decreases or increases is present in chlorinated water. Furthermore, activity inducing transformations measured by the non-two-stage assay gradually decreased. This direction of change was reverse to that of activity inducing transformations by the two-stage assay and consistent with that of activity inducing chromosomal aberrations. It is speculated that the main reason of decreasing activity inducing transformations by the non-two-stage assay is because initiating activity detected as activity inducing chromosomal aberrations in chlorinated water decreases drastically. Directions of changes of total organic halogen and carbonyl group were qualitatively consistent with that of activity inducing chromosomal aberrations. Directions of changes of chloroform and dichloroacetic acid were qualitatively consistent with that of activity inducing transformations by the two-stage assay. Findings of this study suggest that further research is necessary to compare carcinogenicity of tap water near water purification plant and distant tap water.

ESR dosimetry of a deceased radiation worker.

A case of overexposure of an industrial radiographer using 192Ir sources and having a filmbadge dosimeter record of 104 mSv has been examined with ESR dosimetry of postmortem tooth and bone specimens. ESR measurements of the tooth enamel showed an intense signal of CO2- and gave the equivalent dose (ED) of 14 Gy by the additive dose method using gamma-rays from a source of 60Co. The doses for a finger bone and humerus were 14.7 and 7.0 Gy, respectively. It was concluded that he had been exposed to radiation repeatedly over 10 yr and that ESR dosimetry can give a life-long cumulative dose for personnel using radiation.

[Hypergastrinemia and type A gastritis in Basedow's disease].

Hypergastrinemia is a very important clinical condition for the reason that a growing body of evidence obtained from animal and human experiments has revealed gastric carcinoids induced by hypergastrinemia. We investigated 35 patients with Basedow's disease (BD) to elucidate the mechanism of hypergastrinemia associated with BD as well as the relationship between type A gastritis and BD. Fasting serum gastrin levels in BD (296.1 +/- 251.4 pg/ml; mean +/- S.D.) were significantly (p less than 0.001) higher than those in age-matched 27 healthy subjects (106.1 +/- 69.2), and in the BD group, significant positive correlation was detected between fasting serum gastrin levels and thyroid hormones (i.e. T3 and free T4). In the hyperchlorhydria group in BD with hypergastrinemia, the levels of fasting serum gastrin were normalized after euthyroidism was attained due to antithyroidal drugs. On the other hand, in the achlorhydria group in BD significant hypergastrinemia was persisted in spite of normalization of thyroid function. Twenty % of the BD patients had histologically proved type A gastritis with achlorhydria, and all patients with type A gastritis were older than 60 years old. Endoscopic examination revealed that one patient with type A gastritis had an early gastric cancer. However, no gastric carcinoids were demonstrated in this study. In conclusion, the results described as above suggested, 1) hypergastrinemia observed in patients with BD may be induced by gastrin hypersecretion due to hyperthyroidism as well as type A gastritis, 2) BD patients with type A gastritis were recommended to undertake regular endoscopic examination for detecting gastric cancers as well as gastric carcinoids.

[A case report of aldosterone-producing adrenocortical adenoma complicated with chronic renal failure associated with nephrocalcinosis: review of APAs complicated with chronic renal failure].

A 57-year-old man was admitted to our hospital because of dyspnea due to congestive heart failure caused by hypertensive heart disease in September, 1992. Twenty years ago, he was diagnosed to be hypertensive, and in 1980, he was diagnosed to at our hospital to have primary aldosteronism (PA) due to a right aldosterone-producing adrenocortical adenoma (APA). There were no hypertensive vascular complications at that time. He refused surgical removal, and anti-hypertensive drugs including spironolactone were administered. However, his drug compliance was very inaccurate. On this recent admission, left ventricular hypertrophy associated with impaired contractivity, hypertensive retinal change and mild protein uria were noted, but no hematuria was detected. His renal function was impaired (Ccr: 15.2ml/min). An abdominal CT scan showed a typical right APA, bilateral renal atrophy and fine granular calcification at renal medulla, even though he had no hypercalcemia and hypercalciuria. In addition, multiple cerebral infarction was demonstrated by a brain CT scan, along with coronary artery stenoses at the right coronary artery and left circumflex branch by coronary angiography and bilateral multiple renal artery stenoses by renal angiography. Right adrenalectomy and renal biopsy were performed. Histological examinations revealed a yellow tan-colored APA, many sclerotic glomerulus, and severely hyarinized renal arterioles. After adrenalectomy, blood pressure was not normalized but was controlled easily by hypotensive agents. Impaired renal function was not improved and deteriorated slightly but did not get worse there after. Since 1959, including ours, 22 cases of APAs complicated with chronic renal failure were reported in Japan. In conclusion, surgical removal should be recommended for APA, even if the patient's condition is complicated with chronic renal failure.

Wideband deep penetration of photon-number fluctuations into the quantum regime in series-coupled light-emitting diodes.

Experimental results on the squeezing of photon-number fluctuations of series-coupled LED's driven by a constant-voltage source are presented that illustrate the advantage of series-coupled LED's, namely, a greater squeezing capability than that of a single LED driven through an equivalent series resistor. We discuss the microscopic origin of the deep squeezing on the basis of quantum-mechanical Langevin equations.

Death of a classified worker probably caused by overexposure to gamma radiation.

This paper describes the case of an industrial radiographer who was seriously overexposed to gamma radiation. The exact circumstances of this exposure were not established but it was concluded that he was repeatedly irradiated probably to a total average whole body dose of at least 10 Gy over several years. Also, a much larger dose to a hand required its partial amputation. He developed myelodysplasia, which progressed to acute myeloid leukaemia from which he died. Karyotypic examination of the leukaemic blasts showed changes very similar to those associated with secondary leukaemia that may develop after radio or chemotherapy. The paper describes his medical case history, the investigation of his workplace, and the attempts to estimate his radiation dose by chromosomal analysis of blood lymphocytes and electron spin resonance of dental enamel and bone.