Mitotic and meiotic detection of radiation-induced translocations in mouse stem cell spermatogonia using fluorescencein situ hybridization

The efficiency of two methods of detection of translocations induced in mouse stem cell spermatogonia by X-ray doses of 2, 5 and 7 Gy was compared: classical multivalent analysis at diakinesis-metaphase I of meiosis and observation via fluorescencein situ hybridization analysis of mitotic or meiotic stages. Specific DNA libraries for chromosomes 1, 11 and 13 were used. The results obtained indicate that (a) chromosomes 1, 11 and 13 are more involved in multivalent formation than expected on the basis of DNA content and (b) if the mitotic FISH analysis data are corrected for the observed over-representation, the frequencies of induced translocations are similar to those recorded in the classical multivalent studies, suggesting equal scoring efficiencies in both systems.     

Risk of death from acute pancreatitis

Summary Conclusions The analysis of all the data available in 192 patients at 24 h from admission shows that only serum glucose above 250 mg/dL (13.88 mmol/L) and serum creatinine above 2 mg/dL (176.8 μmol/L) are prognostic factors of death (P<0.0001). When, however, pathological chest X-rays are also considered in a subset of 149 patients, these and serum creatinine are prognostic factors of death with odds ratios of 2.9 (95% CL 1.3–6.3) and 9.4 (95% CL 2.2–40.7), respectively (P<0.0001). Background In patients suffering from acute pancreatitis, neither Ranson scores nor Glasgow criteria evaluation at 24 h yield a sufficiently reliable prognosis of the risk of death from the first acute attack. Methods After excluding posttraumatic, postsurgical, and post-ERCP acute pancreatitis, we selected 192 consecutive patients admitted in the first instance to our center for a first attack, distinguishing between patients who died and patients who survived. We used Cox's model to analyze the prognostic weight of variables available within 24 h of admission (sex, age, alcohol intake, smoking habits, 17 biochemical tests, body mass index, chest X-rays, body temperature, and shock status). Results Seventeen (8.8%) patients died; mortality showed a decreasing trend over the period of years considered and was correlated, among other things, with necrotizing type of pancreatitis, idiopathic etiology, and shock status on admission.     

X射线照射量(治疗水平)标准装置的研究和建立

Ｘ射线照射量（治疗水平）标准装置是由标准剂量仪，Ｘ射线照射源，测量车、定位系统及其辅助设备组成，本文作者主要介绍标准装置各个部分的构成及技术参数，该标准装置于１９９１年通过国家技术监督局认证，尔后，正式开展放射仪表的检定和校准工作。     

唇腭裂患者手术后上颌骨发育的评价研究

目的　研究唇腭裂术后患者上颌骨发育特征及手术对发育造成的影响。方法　将 6 0例婴幼儿期手术的完全性唇腭裂患者作为研究对象 ,采用X线头影测量方法进行测量 ,拍摄标准侧位头影测量片 ,并选择 12个标志点及 12个测量项目 ,并与同年龄段正常患者的测量值进行比较分析。结果　单纯唇裂患者与正常对照组比较出现∠SNA [(76 .4± 3.0 6 )° ,P 0 .0 5 ]、N A Pg[(- 4 .8± 6 .31)mm ,P 0 .0 5 ]值变小 ;单纯腭裂及唇腭裂患者出现∠SNA[(74 .5± 4 .0 1)° ,P 0 .0 5 ;(75 .1± 1.0 7)°,P 0 .0 1]、N ANS[(47.3± 2 .4 1)mm ,P 0 .0 1;(49.8± 1.91)mm ,P 0 .0 1]等多项指标均小于正常对照 ,提示不同程度、不同表现形式的上颌骨发育受限。结论　唇腭裂患者术后上颌发育不足是先天及后天因素综合影响的结果。唇裂修复术是影响上颌前后向发育的重要因素之一 ,腭裂修复术是影响上颌骨高度及宽度发育的重要因素之一。     

The first 50 years of military radiology 1895–1945

Following the discovery of X-rays in 1895 by Wilhelm Röntgen the value to the military surgeon of the new technique was soon realised. The localisation of retained bullets by radiography avoided inappropriate exploration of the wound. The X-rays were first used on casualties from the Abyssinian War of 1896 and the developing radiological technology was progressively applied to military surgery. In addition the needs of warfare stimulated the development of all aspects of radiology.     

Dose- and time-dependent responses for micronucleus induction by X-rays and fast neutrons in gill cells of medaka (Oryzias latipes)

Medaka fish (Oryzias latipes) were exposed to various doses of X-rays or fast neutrons, and the frequency of micronucleated cells (MNCs) was measured in gills sampled at 12- or 24-hr intervals from 12 to 96 hr after exposure. The resulting time course of MNC frequency was biphasic, with a clear peak 24 hr after exposure, irrespective of the kind of radiation applied and the dose used. The half-life of MNCs induced in the gill tissues by the two exposures fluctuated around 28 hr, with no significant dose-dependent trend for either X-ray- or neutron-exposed fish. As assayed 24 hr after exposure, the MNC frequency increased linearly over the control level with increasing doses of both X-rays and fast neutrons. The relative biological effectiveness (RBE) of fast neutrons to X-rays for MNC induction was estimated to be 4.3 +/- 0.6. This value is close to the RBE value of 5.1 +/- 0.3 reported for fast neutron induction of somatic crossing-over mutations in Drosophila melanogaster that arise from recombination repair of DNA double-strand breaks. These results and other data support our conclusion that the medaka gill cell micronucleus assay is a reliable short-term test for detecting potential inducers of DNA double-strand breaks.     

放射性肺炎的X线和CT诊断

目的：对比分析放射性肺炎的常规Ｘ线和ＣＴ特点,评价ＣＴ对本病的诊断价值。方法：回顾性分析４６例放射性肺炎的常规Ｘ线和ＣＴ表现。结果：放射性肺炎的典型表现为照射野内散在分布小灶性渗出性病变;形态与照射野一致的大片密度增高影;肺间质增厚和（或）肺纹理增粗;边缘锐利清晰的纤维化影或肺不张,该表现多见于中后期。结论：ＣＴ对放射性肺炎的诊断明显优于Ｘ线,且两者对该病的临床治疗和预后判断具有重要意义。     

Radiosensitive populations and recovery in X-ray-induced apoptosis in the developing cerebellum

Sprague-Dawley rats received a single dose of 2 Gy X-rays at the age of 1 or 3 days and were killed at different intervals. Dying cells with the morphological characteristics of apoptosis appeared in the external and internal granular layers (EGL and IGL) and white matter (WM) of the cerebellum, mainly 3–6 h after irradiation, and decreased thereafter to reach normal values between 48 h and 5 days later. This process was curbed by the injection of cycloheximide at a dose of 1 g/g body weight. In addition, the number of mitoses in EGL rapidly decreased after irradiation and did not reach normal values until a few days later. Proliferating cell nuclear antigen (PCNA)-immunoreactive cells, which were chiefly found in EGL but also in IGL and WM, dramatically decreased in number from 3 to 48 h after irradiation. PCNA-immunoreactive cells reappeared and reached age-matched values in the following days. Hu (considered as an early neuronal marker) and vimentin immunocytochemistry disclosed that Hu-nonreactive cells in the upper level of EGL, Hu-immunoreactive cells in the inner level of EGL, Bergmann glia and many astrocytes in WM, as well as many non-typified cells in WM, were radiosensitive populations, whereas Purkinje cells were not. The present results indicate that irradiation at P1 or P3 blocks mitosis in EGL and kills sensitive cells mainly in the late G1 and S phases of the cell cycle, probably by apoptosis through a protein synthesis-mediated process. Radiosensitive cells are germinal cells and neuroblasts in EGL, Bergmann glia, astrocytes in WM, and non-typified cells, probably glial cell precursors, in WM. Surviving cells in EGL and PCNA-immunoreactive cells in other cortical layers and white matter reconstitute the cerebellum following a single dose of X-rays.This work was supported in part by CEC project FI3P-CT92-0015 and FIS grant 93-131. M. Olivé is the recipient of a grant from the Pi i Sunyer Foundation. R. Rivera has a grant from the CIRIT     

GM1 ganglioside treatment protects against long-term neurotoxic effects of neonatal X-irradiation on cerebellar cortex cytoarchitecture and motor function

Exposure of neonatal rats to a 5 Gy dose of X-irradiation induces permanent abnormalities in cerebellar cortex cytoarchitecture (disarrangement of Purkinje cells, reduction of thickness of granular cortex) and neurochemistry (late increase in noradrenaline levels), and motor function (ataxic gait). The neuroprotective effects of gangliosides have been demonstrated using a variety of CNS injuries, including mechanical, electrolytic, neurotoxic, ischemic, and surgical lesions. Here, we evaluated whether systemically administered GM1 ganglioside protects against the long-term CNS abnormalities induced by a single exposure to ionizing radiation in the early post-natal period. Thus, neonatal rats were exposed to 5 Gy X-irradiation, and subcutaneously injected with one dose (30 mg/kg weight) of GM1 on h after exposure followed by three daily doses. Both at post-natal days 30 and 90, gait and cerebellar cytoarchitecture in X-irradiated rats were significantly impaired when compared to age-matched controls. By contrast, both at post-natal days 30 and 90, gait in X-irradiated rats that were treated with GM1 was not significantly different from that in non-irradiated animals. Furthermore, at post-natal day 90, cerebellar cytoarchitecture was still well preserved in GM1-treated, X-irradiated animals. GM1 failed to modify the radiation-induced increase in cerebellar noradrenaline levels. Present data indicate that exogenous GM1, repeatedly administered after neonatal X-irradiation, produces a long-term radioprotection, demonstrated at both cytoarchitectural and motor levels.     

Effect de la Substitution de D2O à H2O sur L'altération de la Myosine B en Solution par la Chaleur et par les Rayons γ du 60Co

Summary

(1) Cette étude montre que les altérations de la myosine B provoquées par la chaleur et par l'irradiation aux rayons γ sont—telles qu'elles apparaissent à l'ultracentrifugation analytique—qualitativement semblables.

(2) Nous avons observé un effet isotopique considérable de la présence de 75 pour cent de D₂O dans le solvant sur la sensibilité de la myosine B envers ces deux agents, et nous avons présenté une tentative d'explication de ce fait.

(3) Les polymères qui apparaissent après un traitement par la chaleur de la myosine B semblent être d'une nature très différente des polymères que l'on voit apparaître après un traitement identique de la myosine A. Ceux obtenus à partir de la myosine B sont dépolymérisables par l'intermédiaire de l'ATP et ils apparaissent dans une zone de température beaucoup plus étroite que celles de la myosine A. Ce dernier fait indique une différence considérable de l'enthalpie d'activation des deux réactions.