[en] Stimulative effect of low dose from ¹⁴⁷Pm radiation on DNA repair of germ cells in spermiogenesis stages was studied by alkaline elution technique. For labelling spermatids DNA, male BALB/C mice were given intra-testicular injection of ³H-TdR in advance. After 36 days of labelling, spermatozoa were sampled that is just the period of germ cells to mature. The period from intraperitoneal injection of ¹⁴⁷Pm to sampling spermatozoa was 12 days. After sperm cells have been lysed, 30 mL eluent was added in, then the flowrate was adjusted by the pumping speed. Finally, the DNA in filters and bottles were determined by radioactivity of labelled nuclides with a Backman liquid scintillation device. Results showed that after small dose of irradiation with 185 Bq/g of ¹⁴⁷Pm, an increase of sperm DNA on the filter was observed that was considerably higher than the control group. This indicates that low level radiation from ¹⁴⁷Pm has tendency to stimulate the capacity of DNA repair in spermiogenesis stages

[en] Stimulative effect of low dose irradiation with ¹⁴⁷Pm on DNA repair of germ cells in spermiogenic stages was studied by alkaline elution technique. Male BALB/c mice were given intratesticular injection of ³H-TdR in advance to label spermatid DNA. After a period of 36 days of labelling, which was coincident with a developmental cycle for the germ cells, spermatozoa were sampled. The period from intraperitoneal injection of ¹⁴'7Pm to spermatozoa sampling was 12 days. When sperm cells were lysed, 30 ml eluent was added in, then the flowrate was adjusted by the pumping speed. Finally, the DNA in filters and bottles were determined by radioactivity of labelled nuclides with a Beckman liquid scintillation device. Results showed that after small dose of irradiation with 0.185 kBq/g of ¹⁴⁷Pm, the retention of sperm DNA on the filter was increased, which was considerably higher than that in the control group. This indicates that low level radiation from ¹⁴⁷Pm has a tendency to stimulate the capacity of DNA repair in spermiongenic stages

[en] DNA synthesis and unscheduled DNA synthesis (UDS) in lymphocytes of spleen, the peripheral immune organ, and DNA repair of germ cells in spermiogenic stages were investigated in BALB/c mice while exposed to internal contamination of enriched uranium at different doses. The experimental results indicated that proliferation DNA synthesis and ultraviolet-induced UDS of splenic lymphocytes as well as DNA repair of germ cells in spermiogenic stages were significantly stimulated by low doses of enriched uranium ²³⁵UO₂F₂. But when the dose of enriched uranium ²³⁵UO₂F₂ increased to 100 μg/kg, DNA synthesis of both splenic T and B lymphocytes were significantly depressed and ³H-TdR incorporation was significantly decreased. When the dose of enriched uranium ²³⁵UO₂F₂ increased to 500 μg/kg, UDS of splenic lymphocytes and DNA repair of germ cells in spermiogenic stages were also significantly depressed

[en] The purpose of the present study was to ascertain comparative retention of ¹³⁴Cs or ¹⁴⁷Pm in skeleton on induction of chromosome aberrations and PCE's micronucleus formation in bone marrow cells. Results indicated that after iv signal nuclide ¹³⁴Cs, through 7 weeks observation, the retention data in skeleton could be well described by an exponential expression. Experiments indicated that the retention value and the absorption dose of ¹⁴⁷Pm in skeleton were significantly higher in comparison with ¹³⁴Cs. Both internal contamination of ¹³⁴Cs or ¹⁴⁷Pm could induce chromosome aberrations and PCE's micronucleus formation in bone marrow cells. Among the type of chromosome aberrations of bone marrow cells induced by ¹³⁴Cs or ¹⁴⁷Pm included gap, chromatid breakage, chromosome breakage and translocation. Moreover, the chromosome aberration rates were elevated when the intake of radioactivity of ¹³⁴Cs or ¹⁴⁷Pm were enlarged. At the same time, chromosome fragment of bone marrow cells also induced by ¹³⁴Cs or ¹⁴⁷Pm only through high radioactive contamination. Studies showed that chromosome translocation was appeared only through high radioactivity of ¹⁴⁷Pm contamination. By comparing with ¹'4⁷Pm, however, the induction of chromosome aberrations and PCE's micronucleus formation rates on bone marrow cells induced by ¹³⁴Cs was quite low

[en] The immune system is the important part of defense mechanism in organism. Studies have demonstrated the high radiosensitivity of the immunocytes to internal radionuclide exposure. It is evident that serious functional disturbances and morphological changes of immune organs are induced by internal contamination of radionuclides, including suppression of division and proliferation of immunocytes, induction of irreversible sequelae, leading to injurious effects on both central and peripheral immune organs. In order to study the consequences of the injuries of genetic material caused by internal contamination of radionuclides, researches have developed from the harmful effects on parental generation to those on the offspring. The present paper reports the study on the genetic injuries of somatic and germ cells induced by internal radionuclide exposure. Emphasis is placed on the molecular basis of radio-genetic effect and the relations of the molecular basis of DNA injury to gene mutation and chromosome aberration

[en] The metabolic peculiarities of renal radiotracer ^99mTc-PAHIDA and diagnostic use were studied. The results of the radioactive tracing study showed that ^99mTc-PAHIDA was distributed predominantly in kidney, and then in heart, gastrointestinal tract, liver, spleen, musculus quadriceps femoris, adipose tissue, testes and brain. It should be noted that when smaller dose of this agent was given, more ^99mTc-PAHIDA was concentrated in kidney and, at the same time, the level of its binding to plasma protein was lower. The experimental results indicated that ^99mTc-PAHIDA was rapidly excreted in urine. Autoradiochromatographic examination of the urine showed a single radioactive peak corresponding to the authentic ^99mTc-PAHIDA, indicating that ^99mTc-PAHIDA was excreted in the unchanged form. (3 tabs.)

[en] The purpose of the present study is to ascertain the retention reculiarity in organism by varying doses of ¹⁴⁷Pm and its injury effect on immune cells of bone marrow. The experimental groups of BALB/C strain mice were injected intravenously with 37, 1.85 x 10², 9.25 x 10², 3.7 x 10³, 1.85 x 10⁴ and 1.85 x 10⁵ Bq/g respectively. The radioactivities in liver, kidney, skeleton, lung and blood samples were determined by liquid scintillation. The results showed that the most of ¹⁴⁷Pm was deposited in skeleton, then in liver, blood, kidney and lung. The absorbed doses in skeleton increases as the intake of ¹⁴⁷Pm increases. At the same time, the incorporation of ³H-TdR in immune cell of bone marrow is remarkably decreased. It shows, under the radiation of ¹⁴⁷Pm, the DNA synthesis function is inhibited, and the immune cell of bone marrow is seriously injured

[en] The purpose of the present study was to ascertain the correlation between the different ionic radius of rare earths nuclides such as ¹⁷⁰Tm, ¹⁵²Eu, ¹⁴⁷Pm and its accumulation peculiarity as well as induction of mutagenic effect on bone marrow cells. The study showed that the accumulation peculiarity of rare earths nuclides will vary with the ionic radius. The results indicated that large ionic radius of ¹⁴⁷Pm was selectively localized in liver in early stage, while small ionic radius of ¹⁷⁰Tm and ¹⁵²Eu were deposited in bone predominantly. There was a positive relationship between the incidence of chromosome aberration rates and the absorption dose in skeleton by ¹⁷⁰Tm, ¹⁵²Eu, or ¹⁴⁷Pm. Studies indicated that the chromosome aberration rates were elevated when the absorption dose in skeleton was increased. Among the type of chromosome aberrations induced by rare earths nuclides with different ionic radius, chromatid breakage was predominant, accompanied with a few chromosome breakage and translocation. At the same time mitosis index of metaphase cells was depressed. Internal contamination of ¹⁷⁰Tm, ¹⁵²Eu, or ¹⁴⁷Pm can be induced by some aberrations in one cell. This phenomenon might be due in part to nonuniform irradiation of bone marrow cell with local deposition of these rare earths nuclides with different ionic radius

[en] For labelling spermatid DNA, male BALB/c mice are injected intratesticularly with ³H-TdR in advance. After 36 d of labelling, spermatozoa are sampled, which is just the time required for the germ cells to mature. The period from intraperitoneal injection of ¹⁴⁷Pm to sampling spermatozoa is 12 d. After sperm cells have been lysed, 30 ml eluent is added by wriggle pump. Finally, both the DNA remained on the filters and filtrated bottles are determined with a Beckman liquid scintillation device. Results show that low level internal irradiation of ¹⁴⁷Pm has tendency to stimulate the DNA repair in spermiogenic stages

[en] Tracer experiment showed that ^99mTc-PAHIDA was distributed predominantly in kidney. The distribution in other tissue was in the following descending order: heart, gastrointestinal tract, liver, spleen, muscle, adipose tissue, testes, and brain. The smaller the intravenous dose, the lower the proportion of the drug was combined to plasma protein and the more the drug was distributed in kidney. Excretion of ^99mTc-PAHIDa via urine was rapid and was in its original form as shown by radiochromatography