方格星虫提取物对雄性小鼠免疫及生殖器官的辐射防护作用

目的 观察方格星虫提取物对y射线损伤雄性小鼠免疫器官及生殖器官的保护作用.方法 将50只雄性小鼠随机分为正常对照组、模型组及低[0.5g/(kg·d)]、中[1.0g/(kg·d)]、高[2.0g/(kg·d)]3个剂量方格星虫提取物组,每天灌胃给药1次,给药剂量为2.0 mL/kg,灌胃2周后,除正常对照组外,各组均以剂量率为0.83 Gy/h的60Co γ射线进行1次全身照射,照射剂量为5 Gy.于辐照前1 d,辐照后第3天、第14天测定小鼠体重、外周血白细胞数,辐照后第14天测定小鼠胸腺指数、脾指数、骨髓有核细胞计数、睾丸重量指数、精子总数及精子畸形率.结果 方格星虫提取物可使辐照后第3天3个剂量组小鼠外周血白细胞数明显高于模型组(P＜0.05),辐照后第14天3个剂量组小鼠的胸腺指数及脾指数明显高于模型组(P＜0.05),低、中剂量组小鼠的骨髓有核细胞数显著高于模型组(P＜0.05),高剂量组小鼠骨髓有核细胞数显著高于模型组(P＜0.01),中、高剂量组睾丸重量指数、精子总数明显高于模型组(P＜0.05),中、高剂量组的精子畸形率显著低于模型组(P＜0.01).结论 方格星虫提取物对辐射损伤小鼠的免疫器官及生殖器官具有一定的保护作用.     

Detection of progressive idiopathic scoliosis during growth using back surface topography: A prospective study of 100 patients

The progression of adolescent idiopathic scoliosis is typically monitored via regular radiographic follow-up. The Cobb angle (as measured on whole-spine radiographs) is considered as the gold standard in scoliosis monitoring.ObjectiveTo determine the sensitivity and specificity of back surface topography parameters, with a view to detecting changes in the Cobb angle.Patient and methodOne hundred patients (mean age: 13.3) with Cobb angles greater than 10 degrees were included. Topographic parameters were measured in a standard position and in a position with hunched shoulders. Gibbosities and spinal curvatures were evaluated.ResultsAn increase of more than 2 degrees in any one gibbosity or in the sum of the gibbosities (in either of the two examination positions) enabled the detection of a five-degree increase in the Cobb angle with a sensitivity of 86% and a specificity of 50%.ConclusionIf the present results are confirmed by other studies, analysis with back surface topography parameters may reduce the number of X-ray examinations required to detect increases in the Cobb angle.     

Low-dose CT of the paranasal sinuses with eye lens protection: effect on image quality and radiation dose

The purpose of the study was to assess the effect of lens protection on image quality and radiation dose to the eye lenses in CT of the paranasal sinuses. In 127 patients referred to rule out sinusitis, an axial spiral CT with a lens protection placed on the patients eyes was obtained (1.5/2/1, 50 mAs, 120 kV). Coronal views were reconstructed at 5-mm interval. To quantify a subjective impression of image quality, three regions of interest within the eyeball were plotted along a line perpendicular to the protection at 2, 5, and 9 mm beneath skin level on the axial images. Additionally, dose reduction of a bismuth-containing latex shield was measured using a film-dosimetry technique. The average eyeball density was 17.97 HU (SD 3.7 HU). The relative increase in CT density was 180.6 (17.7), 103.3 (11.7), and 53.6 HU (9.2), respectively. There was no diagnostic information loss on axial and coronal views observed. Artifacts were practically invisible on images viewed in a bone window/level setting. The use of the shield reduced skin radiation from 7.5 to 4.5 mGy. The utilization of a radioprotection to the eye lenses in paranasal CT is a suitable and effective means of reducing skin radiation by 40%.     

Protective effect of amifostine on dental health after radiotherapy of the head and neck

Purpose: The cytoprotective agent amifostine has been shown to reduce the radiation-induced acute and chronic xerostomia in head and neck cancer patients. The purpose of this study was to evaluate whether or not amifostine also reduces the incidence of dental caries associated with the radiation-induced xerostomia.

Methods and Materials: The dental status before and 1 year after radiotherapy was retrospectively compared in 35 unselected patients treated as part of the prospective randomized and multicenter open-label Phase III study (WR-38) at the University Hospitals of Heidelberg, Freiburg, and Erlangen. The WR-38 study compared radiotherapy in head and neck cancer with and without concomitant administration of amifostine.

Results: Patient and treatment characteristics (particularly the radiation dose and percentage of parotids included in the treatment volume) were equally distributed between the patients who received (n = 17) or did not receive (n = 18) amifostine. Fifteen patients of the amifostine group showed no deterioration of the dental status 1 year after radiotherapy as compared to 7 patients who did not receive the cytoprotector (p = 0.015, two-tailed Fisher exact test).

Conclusion: Our data suggest a protective effect of amifostine on the dental health after radiotherapy of the head and neck. The dental status should be used as a primary endpoint in future studies on amifostine.     

Dephosphorylation of WR-2721 with mouse tissue homogenates

Mouse liver homogenate had an optimum pH of 8.6 to 8.8 for dephosphorylation of WR-2721 in the analyzed pH range from 5.2 to 10.0. At this optimum pH condition, the dephosphorylation activities of six mouse tissue homogenates were analyzed. Kidney, liver and small intestine homogenates showed higher dephosphorylation activities (935, 336 and 314 nmoles/mg protein/hr, respectively) than spleen and lung homogenates (86, 49 nmoles/mg protein/hr, respectively). Furthermore, serum did not show any dephosphorylation activity. The high activity found in liver homogenate agrees well with our previous data with mouse L cells. However, optimum pH from 8.6 to 8.8 in liver homogenate is quite different from the data reported by using Ehrlich ascites tumor cells (optimum pH was 5.6). Therefore, it is suggested that WR-2721 administered into mouse is efficiently dephosphorylated in certain tissues such as liver to its active form with the enzyme(s) different from that found in Ehrlich ascites tumor cells.     

An in vivo study of the radioprotective effect of diethyldithiocarbamate (DDC)

We have recently shown that diethyldithiocarbamate (DDC) protects plateau-phase cultures of mammalian cells from radiation. Experiments in vivo have extended our knowledge of the radioprotective properties of DDC and show that the LD50/30 in mice is increased from 780 rad to approximately 1400 rad when non-toxic concentrations of DDC are present prior to the irradiation. When DDC is present during irradiation, the pattern of death of the mice is similar to that seen in the absence of the drug and is quite different from that seen in animals dying of a gastrointestinal syndrome (LD50/7 congruent to 1700 rad). To confirm that the LD50/30 data represent bone marrow protection by DDC, we performed bone marrow CFUS assays with and without the presence of DDC, at the time of in vivo irradiation. The DO of the CFUS is increased from 80 rad in the control animals to 120 rad in the animals that have been pretreated with DDC. In experiments using 35S-labelled DDC, the tissue distribution of the drug in tumor-bearing mice indicates a preferential uptake of DDC in kidney, lung and bone marrow compared to tumor tissue. Based on data from both in vitro and in vivo studies, we believe that DDC shows promise as a radioprotective agent and should be considered for clinical trials.     

抗氧化物质在辐射防护中的作用

电离辐射对生物体构成损伤,一是辐射能量传递的直接作用,二是通过水在辐解反应中产生的自由基所引起的损伤的间接作用,氧化损伤是辐射对机体损伤的重要机制之一。抗氧化物质可以清除自由基,理应具有辐射防护作用。     

儿童专用X线胸片架的研制

放射技术人员在给儿童作胸部X线照片检查时,儿童自主固定投照体位和对其进行X线放射防护的难度大。本文介绍了一种人性化儿童专用X线胸片架,该胸片架与放射防护器材、协助儿童自主固定的结构和用于稳定儿童情绪的器材融为一体。与普通胸片架相比,其结构更具儿童特色,容易固定儿童胸部X线投照体位、稳定儿童情绪和进行X线放射防护。     

Antitumor, hematostimulative and radioprotective action of water-soluble derivative of propolis (WSDP)

Several studies suggest that dietary supplementation with antioxidant can influence the response to chemotherapy as well as the development of adverse side effects caused by treatment with chemotherapeutic agents. Using CBA mouse model, we investigated a clinically potential use of a water-soluble derivative of propolis (WSDP) in the treatment of various cytopenias induced by radiation and/or chemotherapy. Also, the antimetastatic efficiency of WSDP given intraperitoneally alone or in combination with chemotherapeutic agents and their effects on the blood leukocytes count as well as on hematopoiesis were studied. Tumor was a transplantable mammary carcinoma (MCa) of CBA mouse. Metastases in the lung were generated by injecting viable tumor cells intravenously (iv). WSDP (50 or 150 mg/kg) exerted a significant antimetastatic effect (P < 0.001) when given either before or after tumor cell inoculation. In combined treatment WSDP and Epirubicin profoundly inhibited metastasis formation; this synergistic effect is maximal when Epirubicin and WSDP were administrated after tumor cell inoculation. Positive outcome of combined treatment with WSDP and Epirubicin was also found regarding the number of red and white blood cells in peripheral blood while in mice treated with Epirubicin alone the significant drop in all hematological parameters was noticed on day 13 after tumor cell inoculation. Furthermore, when WSDP (50 mg/kg) was given perorally (po) for 20 consecutive days an increased number of exogenous CFUs was found in treated mice. WSDP given either for 20 or 40 days increased cellularity of hematopoietic tissue and the number of leucocytes in peripheral blood; prolonged treatment with WSDP also elevated myeloid and megakaryocytic types of CFUs. To conclude, these findings indicate that the combination of WSDP with chemotherapeutics could increase the antimetastatic potential of chemotherapeutic agents; these findings suggest the benefits of potential clinical trials using WSDP combined with chemotherapeutic agents in order to maximize their antitumor activity and minimize postchemotherapeutic or radiotherapeutic deteriorated reactions.