1982年 · 第02卷第05期

The intestinal movement of mice after 1500 rad ⁶⁰Co γ-ray irradiation was studied on the isolated ileum preparations. It was revealed that (1) the amplitude of ileal movement decreased 3~4 days after irradiation; (2) the ileum of irradiated mice was much more sensitive to both a-and β-adrenergic drugs than that of normal mice; (3) the reactivity of ileum to acetylcholine did not how any regular change; (4) the reaction of ileum to papaverine was remarkedly increased after irradiation (up to 20 folds of the normal), indicating that the myogenic factor played a very important role in the above mentioned change. These suggest that the ileum of lethally irradiated mice is much more sensitive to the relaxant and thus less effective in maintaining the equilibrium between sympathetic and parasympathetic sys tems when different stimuli are given.

Wistar rats inhaled radon and daughters in an exposure cabinet for several weeks with accumulated dose up to 3500 WLM. As result, the chromosome aberration frequencies in the blood and lymphatic nodes of experimental animals did not show any increase over the control group. But when the human blood was directly exposed to high concentration of radon and daughters in vitro about 120 WLM, the chromosome aberration rate was greatly increased to a level as if the blood has been irradiated by 200~300 R X-rays.

All informationbased on animal experiment and irradiated human blood in vitro would support the view that the chromosom aberration in blood lymphocytes was induced by γ-ray exposure and not by radon and daughters, and that the dose of inhaleed radon and daughters had been significantly attenuated when it came into blood stream from the respiratory tract.

Total body irradiation (TBI) has been known to be an effective therapy in lymphoma and leukemia. This paper presents the results of our first 14 cases of chronic leukemia (CML 12 cases, CLL2 cases) treated by TBI during the period from September 1979 up to May 1981.

The criteria of clinical diagnosis of these patients were based upon its histories, relevant physical and hematologic findings. The accumulated exposure dose varied between 150 to 250 rads in each case.

At discharge from the hospital, the therapeutic effect on each case was judged by clinical status and hematologic indices: 5 cases achieved complete remission, 7 cases in partial remission, and 2 cases getting better.

When the accumulated exposure doses were less than 100 rads, the total white counts and the absolute values of neutrophils dropped gradually, and when they were more than 100 rads, a slight gradient of both counts might be seen. The absolute values of lymphocytes in 2 cases of CLL dropped sharply after irradiation.

After the TBI, all the stem cell cultures from the bone marrow specimen revealed a dropped yield of CFU-C. Besides, both abnormalities of chromosomes and the supermicro-structures of bone marrow cells were observed. This paper revealed that the lymphocytes were especially sensitive to irradiation. We are now going to search for the other sensitive radiobiological indices in lymphocytes.

The changes cf hemoglobin content in bone marrow were measuredsimu taneously with the number of BM nucleated cell and spleen weight index in the mice irradiated with various doses (200, 600 and 1000 rads). The results showed that: 1) The Hb content of BM varied directly with irradiation doses. The higher the dose, the earlier, higher and longer it increased. 2) In BM, the changes of Hb content and nucleated cell number were in contradiction with each other and they showed an aggravating effect with each other. 3) The Hb content was markedly increased after irradiation, seeming more sensitive than the other indices. 4) The increase of Hb content is the result of RBC redistribution in vivo. 5) The above mentioned regularity is in agreement with the morphological alteration in microcirculation of irradiated mice reported in literature. It might be concluded that the Hb content in BM is an indirect index of BM microcirculation disturbance following radiation.

In this paper radiation reactions in 20 cases of malignant tumors exposed to accidental whole-tody irradiation and those in 30 cases of maignant tumors receiving normal radiotherapy are evaluated. The main difference in reactions between these two groups is the degree and the time of appearance of the reactions. In the latter group, the reactions appeared about 3~5 days after irradiation with an incidence of not more than 50%; they were of mild degree, and the change of WBC in the peripheral blood was not evident. In the former group, however, about 75~85% of patients displayed reactions in the same day of irradiation, and the remaining 15~25% in the next day, with greater severity and longer duration, the decrease of WBC in peripheral blood being obvious.

The type and severity of reactions in accidentally exposed patients were closely related to the part of body irradiated. When abdomen was irradiated, the patients suffered from loss of appetite, abdominal pain, diarrhea, in creasing frequency of urination and blood in stool; when, however, head and neck were irradiated, oropharyngeal congestion, dryness of the mouth, hoarseness, oral ulcer etc. appeared. It may be considered as a rule of thumb in radiotherapeutic practice that the radiation reactions may be attributed to an abnormal exposure if they emerge at an earlier date, with severer intensity and higher freguercy.

There are a lot of hot springs in Guizhou Province. Of them eighteen major ones were investigated on the radioactivity. The results showed that the concentrations of Uranium, Radium-226, and Radon-222 ranged 0.03~2.06μg/l, 0.19~22.6 pCi/1 and 121~3491pCi/1 respectively. Its significance on public health has been discussed.

Ordinarily, the radioactive equilibrium ratio between gross α-and β-activities remains practically constant in the air, so that any change in α/β value would mean a radioactive contamination. Such an event was satisfactorily verified by the present experiment. The α/β rato method was found to be simple and reliable.

For undisturbed aeroso in the absence of nuclear test, the α/β ratio remained practically constant, while in disturbed air (airborne radioactive contamination) such a ratio showed an appreciable change. When both α-and β-particles were simultaneously present, the α/β ratio measurement could readily serve to warn on radioactive contamination qualitatively or semi-quantitatively.

In this paper an analytical method for determining thorium in soil is presented. It is a direct colorimetric procedure using arsennazo Ⅲ as colour reagent. In order to eliminate the in-terference of other elements, EDTA, triethanolamine, ascorbic acid and oxalic acid were added into colorimetric solution. The factors affecting accuracy, including the interference of other elements and the background of reagent, were investigated. The method yielded satisfactory results.

The radiation level on the surface of various models of China-made and imported household television sets was measured. The results showed that no leakage of x-ray from the kinescope was noticed, while lowlevel radiation on the surface of all TV sets was revealed with the aid of sensitive detectors. It is suggested that the radiation is emanated from ⁴⁰K and rare earth elements in the glass of the kinescope.