[en] A modified new method of autoradiography used in the study of cultured bone marrow cells is reported, which may greatly shorten the exposure time from 7-12 days previously to only four hours now. The successful result of experiment showed possibilty of its application to hematological studies. The rapidity and simplicity of the method indicated it was particularly suitable to clinical hematological work. In addition, the ³H-Thymidine-labelling rate of the cultured bone marrow cells of normal mice obtained by this method was reported in the paper as well

[en] Pregnant Wistar rats were exposed to a single whole body γ-rays at doses of 0.25, 0.50, 1.0 Gy on day 13 of gestation, dose rate of 19.6 R/min. Pregnant rats were killed on the 20th day after conception. Fetuses were examined and measured. The results show that growth retardation in groups 0.5 and 1.0 Gy was observed by fetal weight, length, weight of the brain with spinal cord, skeleton development and microscopic examination of the brains. The changes were dose-dependent. 0.25 Gy could be a treshold dose. It merits attention that the developing brains of fetal rats are sensitive to ionizing radiaion. Brain weight of fetal rats exposed to 0.5 Gy was reduced (P < 0.05), brain weight reduced obviously (P < 0.01) in 1.0 Gy group. Cells in telencephalon cortical layer were arranged disorerly. Some such as olfactory bulb, subiculum. The possible mechanism was discussed

[en] The pregnant Wistar rats were exposed to 0.5 Gy and 1.0 Gy ⁶⁰Co γ-rays at the 9th day after conception. The results: ⁶⁰Co γ-rays at dose of 1.0 Gy could induced many defects: excenphaly, hydrocephalus, gastroschisis, cleft palate and cleft lip, anophthalmia, microphthalmia, shorten tail and absent tail in surviving fetuses. The growth retardation was found from the parameters of fetal weight, height, head circle and development of skeleton. In the group of radiation dose 0.5 Gy, only hydrocephalus, absent tail and growth retardation of skeleton appeared. The results suggest that low-dose exposure in the early pregnant rats can induce fetal defects and growth retardation. The probable mechanism of teratogen and growth retardation was discussed. The cAMP levels of brain and liver of rat fetuses were reported

[en] ¹³¹I-labeled anti-ovarian epithelial adenocarcinoma monoclonal antibodies (McAb) COC166-9, COC183 B₂ raised in Gynecologic Oncology Research Laboratory were used to investigate the localization and biological distribution in human ovarian carcinoma xenograft in nude mice. Radioimaged tumor had been shown 24 hours after administration of ¹³¹I-labeled McAb. It was more clear 48 to 72 hours later. The localizations and the sizes of the sizes of the tumor could be clearly visualized in the gamma scintigrams which were corresponding with the tumors grown in the nude mice. Negative results were found in control groups. Tumor/blood ratios were determined at 24, 48, 72 and 96 hours respectively after injections of ¹³¹I-COC183 B₂. High peak 1.09 was found after 72 hours against 0.16 in the control. The radios of tumor tissue/non-tumor tissue 4.38 at 48 hours, 2.46 at 72 hours, but 1.11 in the control at 72 hours. The different radioactivities expressed as cpm/gm were edtermined in tumors weighing 34 mg, 70 gm, 120 mg and 400 mg respectively and the results were not very much different from each other. Nevertheless, tumor weighing less than 70 mg could not be detected by this procedure. Perhaps this is related with the sensitivity of the equipment. Obviously more work has to be done for the extrapolation from animal studies to human, however, the above results may provide valuable clues for eventual application of this procedure to patients with ovarian cancer

[en] The primary sensory neurons innervating the upper and lower first molars of the rat were studied by ³H-HRP autoradiography with respect to their localization in the trigeminal ganglion. The results showed labelled neurons were found only in the ganglion ipsilateral to the injection; the lablled neurons innervating upper and lower first molars might be divided into somatotopic areas, however, they intermingled and overlapped in the ganglion. The present findings seem to be of value for studying the mechanisms of odontogenious referred pain

[en] The present research is an attempt to study the psychological effects of long-term exposure to low-level X-ray on man. The subjects included 50 exposed people and 50 control. The battery of psychological tests consists of 10 subtests mainly involving memory and coordination ability. The results indicate that there are no statistical differences in all subtests between exposure and control group, but exposure group appears to be a little lower on most subtests about memory. With age, decline of psychological function is observed in all subtests in both groups. The subjects are further divided into three subgroups according to the number of X-ray exposed years. No statistical differences are found in all subgroups between exposure and control. Factor analysis has been made and two factors are obtained. factor 1 is mainly about speed of coordination, factor 2 is mainly about memory and attention. No statistical differences in factor scores are observed in all subgroups between exposure and control. Yet decline is found in factor 1 and factor 2 in both exposure and control groups with age. The results show that there is no significant effect of current dose level of X-ray exposure on human psychological function

[en] N-Dimethylnitrosamine (NDMA) in some marine foods, such as dried shrimp, fish meal and salted fish, was drastically reduced by γ-ray irradiation with ⁶⁰Co. The shrimp contained 54.6 ppb NDMA, but only 29.3, 8.8, 11.4, and 1.9 ppb were detected after irradiation with doses of 5, 10, 15 and 20 kGy. The corresponding reduction was 46.3%, 83.9%, 79.1%, and 96.6%, respectively. Similar results were also obtained in other two kinds of foods. NDMA could be completely eliminated by the irradiation in aqueous solution, which was much more markable than that in food samples. The major irradiated products of NDMA were dimethylamine and nitrous acid, but no re-formation of nitrosamines took place. ⁶⁰Co irradiation also significantly decreased the content of nitrite in salted fish and in aqueous solution. No effect on nitrate could be observed