尼尔雌醇照前多次给药对骨髓型急性放射病小鼠的防护作用及其机制研究

目的 了解抗放药尼尔雌醇照前不同给药方案对⁶⁰Co γ射线照射所致小鼠骨髓型急性放射病的防护效应的影响,并揭示其促造血恢复机制。方法 采用外周血象分析和存活率实验确定尼尔雌醇较优给药方案,再以骨髓造血干/祖细胞表面标志分析、多系骨髓细胞集落及骨髓HE病理切片等方法,分析尼尔雌醇照前2次间隔给药促进照后骨髓造血恢复的作用机制。结果 尼尔雌醇照前3次间隔给药与2次间隔给药均能提高9.0 Gy照射小鼠存活率至100%,明显优于1次给药(20%, χ²=21.66、21.66,P<0.05)。尼尔雌醇照前3次连续给药与2次间隔给药均能改善6.5 Gy照射小鼠外周血白细胞、中性粒细胞、血小板和红细胞的恢复(F=21.33、100.9、49.34、19.19, P<0.05),且比1次给药效果好(F=17.11、63.38、21.89、14.37, P<0.05)。尼尔雌醇2次间隔给药显著提高6.5 Gy照射后小鼠10 d骨髓造血干、祖细胞数(t=8.58、2.80, P<0.05);显著增强小鼠骨髓造血细胞集落形成能力,与1次给药相比,差异有统计学意义(t=4.29、6.34, P<0.05)。同时,2次间隔给药明显改善照射小鼠骨髓象的重建。结论 与传统的照前单次给药相比,尼尔雌醇照前多次给药可显著提升其对小鼠骨髓型急性放射病的辐射防护效果。考虑到核医学应急救援的实际情况,建议尼尔雌醇照前采用间隔1 d的给药方式,在减少尼尔雌醇给药次数情况下,以获得最佳的抗放效果。     

骨形成蛋白对造血的影响

骨形成蛋白(ｂｏｎｅｍｏｒｐｈｏｇｅｎｅｔｉｃｐｒｏｔｅｉｎ,ＢＭＰ)对造血损伤的治疗作用,是近年来放射损伤研究新的视点之一。本文仅就这一研究的动向及有关的问题作一阐述。一、ＢＭＰ的发现和应用1965年由Ｕｒｉｓｔ首次报道:牛的脱钙骨基质植入肌肉,可诱导新的软骨和骨组织的形成。1967年他根据以往所做的研究提出了骨诱导物质的概念(ｂｏｎｅｉｎｄｕｃｔｉｏｎｐｒｉｎｃｉｐｌｅ,即ＢＩＰ)[1]。经过多年的研究,这种基质被命名为骨形成蛋白ＢＭＰ[2]。ＢＭＰ是ＴＧＦβ家族的一员,是一种分化生长因子。它与其他细胞因子仅刺激相…     

血小板第4因子对放射损伤小鼠骨髓基质细胞周期的影响

目的探讨血小板第4因子（platelet factor 4,PF4）对5.0 Gy γ射线全身照射小鼠的骨髓基质细胞（bone marrow stromal cells,BMSCs）的保护作用,进一步探讨PF4对造血的辐射防护机制.方法30只雄性小鼠随机分为3组：①放射组,②PF4保护组,③对照组.小鼠照射前分别于26和20 h腹腔内注射PF4,每次剂量50 μg/kg.于照射后3 d取骨髓细胞体外培养,分别计数培养后3、7和14 d的骨髓基质细胞集落（CFU-F）;在培养后10 d流式细胞仪检测细胞周期.结果3组中,照射组3 d的CFU-F数量与PF4保护组差异无统计学意义,7和14 d的CFU-F数量PF4保护组较照射组明显增加.流式细胞仪检测结果表明3组中照射组G0＋G1期细胞明显高于其余两组,S,G2＋M期细胞明显低于其余两组.结论PF4对照射小鼠的骨髓基质细胞有保护作用,促进造血重建.     

辛伐他汀对急性放射损伤小鼠骨髓造血恢复的影响

目的 探讨小鼠受到照射后,辛伐他汀对骨髓造血功能恢复的影响。方法 将66只8周龄清洁级健康昆明小鼠随机分为3组。正常组不做任何处理;对照组和辛伐他汀组于6.0 Gy ⁶⁰Coγ线一次性全身均匀照射后, 分别胃饲等体积的生理盐水和辛伐他汀(16 mg/kg,1次/d),直至处死。于照射后第3、7、10、14 天检测小鼠外周血细胞数和骨髓有核细胞数,并用流式细胞仪检测骨髓有核细胞中CD34+细胞百分率,测量骨髓造血面积,观察照射后第10天小鼠脾集落形成单位(CFU-S)数及第28天骨小梁的变化。结果 照射后第3、7、10、14 天辛伐他汀组小鼠外周血白细胞数、血小板数、骨髓有核细胞数和骨髓CD34+细胞率均明显高于对照组(P<0.05或P<0.01),而外周血红细胞数无明显差异。照射后第28天辛伐他汀组小鼠骨小梁的数目明显多于对照组。辛伐他汀组小鼠CFU-S数(11±3)个显著高于对照组(4±3)个。2组小鼠骨髓造血面积随时间的变化差异有统计学意义(P<0.05)。结论 辛伐他汀能够促进急性放射病小鼠成骨细胞增生、增加骨髓CD34+细胞率并促进骨髓造血功能的恢复。     

成骨细胞促进急性放射损伤小鼠骨髓造血系统及血管恢复的研究

目的 探讨成骨细胞对放射损伤小鼠骨髓造血系统及血管恢复的影响.方法 取18只雄性BALB/c小鼠股骨制备成骨细胞,其余42只小鼠随机分成健康对照组、成骨细胞组和生理盐水组3组.健康对照组不做任何处理;成骨细胞组和生理盐水组小鼠于6.0 Gy 60 Co γ射线一次性全身均匀照射后,分别经尾静脉输入成骨细胞(2×106个/只)和等体积的生理盐水.于照射后第7、14和21天计数小鼠外周血细胞,骨髓单个核细胞并作骨髓组织学观察.采用流式细胞仪检测骨髓单个核细胞中CD34+细胞百分比,采用免疫组织化学方法检测小鼠骨髓微血管密度.结果 照射后第7、14和21天成骨细胞组小鼠外周血细胞和骨髓单个核细胞计数,骨髓单个核细胞中CD34+细胞百分比,骨髓组织造血面积及骨髓微血管密度均明显高于生理盐水组(t=2.46～64.51,P＜0.05).结论 成骨细胞能促进放射损伤小鼠骨髓造血系统及血管的恢复.

Abstract：

Objective To explore the effects of osteoblasts on the recovery of hematopoiesis and angiogenesis in acute irradiation injury mice.Methods The femurs of 18 male BALB/c mice were used to prepare the bone marrow osteoblasts, and the rest mice were divided into 3 groups as normal group, saline group and osteoblast group.The mice in normal group received no treatment, and the other two groups were received 6.0 Gy 60Co γ-ray irradiation.After irradiation each mouse of osteoblast group was administered with 2 × 106 osteoblasts through tail vein injection, and equal volume saline was given to each mouse of saline group by the same way.The following factors were measured at 7, 14, 21 d after irradiation, they were the counts of peripheral blood cells and bone marrow mononuclear cells ( BMMNC ) , the percentage of CD34 + cells in BMMNC, the histology changes and micro vascular density (MVD) of bone marrow tissue.Results The counts of peripheral blood cells, BMMNC and hematopoietic tissue area in osteoblast group were higher than those in saline group.The percentage of CD34 + cells in BMMNC and the MVD of bone marrow in osteoblast group were also higher than those in saline group at 7, 14, 21 d after irradiation ( t = 2.46 - 64.51, P ＜ 0.05 ).Conclusions Osteoblasts could significantly promote the recovery of hematopoiesis and angiogenesis in mice after acute irradiation injury.     

骨形态发生蛋白-7对急性肾缺血再灌注损伤的保护作用

缺血再灌注损伤（ischemia reperfusion injury,IRI）是指各种原因导致脏器或组织严重缺血并在其恢复血液再灌注后组织细胞的功能、代谢和结构出现异常或加重的现象。急性。肾缺血再灌注损伤（ARIRI）是许多急性肾脏疾病最主要的病理生理变化,其机制非常复杂,研究表明主要与氧自由基增多、钙超载、细胞凋亡、中性粒细胞及补体系统活化、     

肿瘤坏死因子α对小鼠骨髓型放射损伤的防护作用

目的：研究肿瘤坏死因子α（ＴＮＦα）对受照射小鼠骨髓造血细胞的近期影响和造血重建功能的作用探讨ＴＮＦα对骨髓造血细胞的辐射防护作用。方法小鼠照射前２４ｈ一次性注射ＴＮＦα,２周后检测共外周血ＷＢＣ、骨髓ＭＮＣ、ＣＦＵ－Ｓ和ＣＦＵ－Ｍｉｘ,流式细胞仪分析骨髓ｃ－Ｋｉｔ＋细胞;并进行长期造血重建实验燧注射ＴＦＮα的小鼠,２周后外周血ＷＢＣ、骨髓ＭＮＣ、内源性ＣＦＵ－Ｓ、ＣＵＦ－Ｍｉｘ数量和ｃ－Ｋｉｔ＋     

放射损伤及烧伤血清对小鼠骨髓基质细胞的影响

为了探讨骨髓基质细胞与放烧复合伤所致造血功能障碍之间的关系 ,观察了不同剂量的γ射线体外照射及照射后培养不同时间对骨髓基质细胞损伤的影响。同种小鼠烧伤后不同时间的血清对基质细胞贴壁率和基质祖细胞 (ＣＦＵ Ｆ)集落形成的影响 ,以及放射损伤复合烧伤血清对体外培养的骨髓基质细胞的作用。一、材料和方法1 实验动物 :昆明种健康小鼠 ,雌雄各半 ,体重 (18～ 2 2 )ｇ ,由第一军医大学实验动物中心提供。2 烧伤小鼠血清的制备 :根据公式Ｓ(ｃｍ ) 2 =9 13Ｗ2 / 3(Ｗ =体重 ,ｇ)计算动物体表面积 ,背部剪毛后 ,3%凝固汽油烧 7ｓ,致 1…     

GM-CSF和rhBMP-2m对小鼠急性放射损伤治疗作用的对比研究

目的 研究和比较重组人骨形成蛋白(rhBMP2m)、GM-CSF对照射后小鼠造血损伤的修复作用。方法 rhBMP2m用分子生物学方法由大肠杆菌中获得; 该实验中rhBMP2m对照射后动物的影响, 通过观察动物的30天活存率表示。结果 照射对照组小鼠的30天活存率为0, 平均活存天数为(9.1±2.2)d;GMSCF治疗组小鼠的30天活存率为20.0%, 平均活存天数为(11.5±1.9)d, rhBMP2m治疗组小鼠的30天活存数为4, 活存率为40%, 平均活存天数为(13.2±6.1)d.结果显示GMCSF和rhBMP2m均能提高受照小鼠的活存率, 并延长活存时间, 而且后者优于前者(P<0.05).结论 rhBMP2m对小鼠急性放射损伤具有治疗作用, 初步观察其优于GMCSF。     

川芎嗪促进急性放射损伤小鼠骨髓造血修复作用的研究

目的　探讨川芎嗪促进急性放射损伤小鼠骨髓造血修复可能的机理。方法　取 5 6只昆明小鼠 ,随机分为 3组 :正常组、对照组和川芎嗪组。对照组和川芎嗪组进行6 0 Coγ射线一次性全身均匀照射 ,总吸收剂量为 6 0Gy ,吸收剂量率为 0 5 6Gy min ,照射后分别胃饲相同剂量 (2mg 只 ,2次 d)的生理盐水和川芎嗪 ,分别于照射后第 3、7、14天计数骨髓单个核细胞 (BMNC) ,检测骨髓组织中造血组织面积和血管内皮生长因子 (VEGF)及骨髓单个核细胞PECAM 1的表达水平。结果　川芎嗪组第 3、7、14天BMNC计数及骨髓造血组织面积均显著高于对照组 (P <0 0 1) ;川芎嗪组VEGF、PECAM 1的表达水平在第 3、7天明显高于对照组 (P <0 0 1) ,而第 14天其表达降低并明显低于对照组 (P <0 0 5 )。结论　川芎嗪可能通过增强骨髓中黏附分子PECAM 1和VEGF的表达 ,以促进急性放射损伤后造血细胞和造血微环境的修复     

阿魏酸对小鼠骨髓造血功能辐射损伤的防护作用

目的 观察阿魏酸对小鼠外周血象和骨髓造血功能辐射损伤的防护作用,初步探讨阿魏酸的抗辐射作用机制。方法 6~8周ICR小鼠96只,随机数表法分为正常对照组、照射模型组、阳性药（408片）治疗组和阿魏酸10、30、90 mg ·kg^-1·d^-1治疗组,每组16只。小鼠初次给药后24 h接受3.5 Gy ⁶⁰Co γ单次全身照射,之后连续7 d给药。其中,每组10只用于观察照射前2 d及照射后3、7、10、15、22 d的外周血象;其余6只用于照射后7 d检测骨髓嗜多染红细胞的微核细胞率、造血祖细胞集落形成能力、以及Thbd和HMGB1蛋白的表达水平。结果 与照射模型组比较,90 mg ·kg^-1 ·d^-1的阿魏酸可有效提高小鼠3.5 Gy照射后3、10、15、22 d的外周血白细胞数（t=2.267、2.399、1.945、2.828,P<0.05）,显著降低骨髓嗜多染红细胞微核细胞率（t=4.013,P<0.05）,明显提高造血祖细胞红细胞集落生成单位（CFU-E）、红细胞爆裂型集落生成单位（BFU-E）和粒-单细胞集落生成单位（CFU-GM）的集落形成能力（t=2.366、2.953、3.115,P<0.05）,并提高骨髓细胞中Thbd和核内HMGB1蛋白表达水平（t=17.75、23.39,P<0.01）。结论 阿魏酸可通过调节Thbd和HMGB1蛋白表达,促进小鼠骨髓造血功能辐射损伤修复,加速外周血象恢复。     

纤维蛋白凝胶复合骨形态发生蛋白及庆大霉素缓释药物的制备及其体内动力学研究

目的 :研制纤维蛋白凝胶复合骨形态发生蛋白及庆大霉素的缓释药物 ,了解其体内药物释放特性。方法 :将复合物植入小鼠股部肌囊中 ,监测术后不同时间点局部组织及复合物的庆大霉素浓度 ,并组织学观察异位诱导成骨情况。结果 :复合物于术后 12h在周围组织产生 (111.3± 13.4) μg·g-1的高浓度 ,并可在 14d内产生高于金黄色葡萄球菌最低抑菌浓度的局部浓度。异位诱导成骨情况良好。结论 :该复合物具有良好的体内缓释作用 ,既可抗感染 ,又可促进骨生长 ,有望成为一期治疗慢性骨髓炎清创后骨缺损的一种简单而有效的方法。     

Evaluation of cell viability,DNA single-strand breaks,and nitric oxide production in LPS-stimulated macrophage RAW264 exposed to a 50-Hz magnetic field

Purpose: Synergistic effects between cellular oxidative stress and magnetic fields may explain the adverse biological effects of 50/60?Hz magnetic fields. To determine whether this hypothesis holds in macrophage RAW264 cells, we measured DNA single-strand breaks (SSB), cell viability, and nitric oxide (NO) production in cells with or without exposure to 0.5-mT, 50-Hz magnetic fields for 24?h and with or without simultaneous stimulation via the bacterial endotoxin, lipopolysaccharide (LPS).

Materials and methods: Macrophages stimulated with 10?ng/ml LPS for 1?h were exposed to or not exposed to a magnetic field and were then subjected to (1) the alkaline comet assay to measure SSBs, (2) trypan-blue exclusion assay for cell viability, and (3) measurements of NO for evaluation of oxidative stress.

Results: The 50-Hz magnetic field enhanced DNA SSB and decreased cell viability only in the LPS-stimulated macrophages in which NO production was greatly enhanced. The magnetic field alone did not alter NO production.

Conclusion: Co-stimulation of the cell with LPS and a 50-Hz magnetic field promoted SSB and lowered cell viability, but these were not mediated by LPS-induced NO production.     

全胸照射引起的大鼠血浆辐射损伤早期代谢特征研究

目的 探索大鼠全胸照射（WTI）后早期血浆代谢特征的变化,为寻找非均匀局部照射辐射损伤生物标志物以及揭示辐射损伤机制提供实验依据。方法 雄性Wistar大鼠按完全随机分组法分为健康对照组和WTI照射组。气相色谱-质谱联用（GC-MS）技术考察大鼠WTI后第2、3、5天血浆代谢物水平的动态变化,筛选出辐射损伤特征差异代谢物,并对其涉及的代谢通路进行探讨。结果 主成分分析（PCA）显示健康对照组和WTI照射组的代谢差异随照后时间的延长愈加明显。与健康对照组相比,WTI后3~5 d,丙氨酸、棕榈酸、硬脂酸、乳酸、葡萄糖等代谢物在血浆中显著性上升（F=13.51、5.20、9.87、10.59、7.05,P<0.05）,蛋氨酸、缬氨酸、苏氨酸、富马酸、苹果酸、α-酮戊二酸、磷酸、赖氨酸等显著性下降（F=15.68、5.63、3.78、12.83、2.88、8.93、4.68、6.43,P<0.05）。结论 WTI照射可引起血浆代谢轮廓改变,差异代谢物主要涉及氨基酸代谢、三羧酸（TCA）循环、脂类代谢等代谢途径。     

Exposure to a 50-Hz magnetic field induced ceramide generation in cultured cells

Purpose To investigate the effects of a 50-Hz magnetic field (MF) exposure on ceramide metabolism, as well as the cascade downstream signaling pathways in human amniotic (FL) cells.

Materials and methods FL cells were exposed to MF at 0.4?mT for different durations (from 5–60?min). The ceramides levels were analyzed with high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The activity of cathepsin D was assayed using a fluorometric assay kit, and the activity of protein phosphatase 2A (PP2A) was examined by Western blotting. After exposing to MF at 0.4?mT for 60?min with sequential culture for different durations (0, 3, 6, 12 or 36?h), the rate of cell apoptosis was assessed by flow cytometry.

Results Exposing cells to MF at 0.4?mT for different durations caused a significant increase in ceramide production via de novo synthesis and hydrolysis of sphingomyelin (SM), and the effect was different according to the exposure time. However, no significant change in cell apoptosis was detected after MF exposure for 60?min with sequentially culturing for up to 36?h. In addition, increase in ceramide did not activate its downstream signal molecules, cathepsin D and PP2A, which are usually closely related to apoptosis of cells.

Conclusions Exposure to a 50-Hz MF could raise ceramide levels but had no significant effect on apoptosis in cultured cells.     

梁金菇多糖对辐射损伤小鼠造血功能的影响

目的：研究梁金菇多糖（LJPS）对造血功能辐射损伤的治疗作用及机理。方法：用造血祖细胞克隆法，内源性脾结节形成法，骨髓有核细胞计数及脾脏指数等方面观察了LIPS对60^Coγ射线照射5．5Gy小鼠造血功能的影响，并用免疫组化法检测辐射骨髓及脾脏细胞的 bcl-2蛋白的表达。结果：LJPS辐射后第7天骨髓CFU－GM，CFU－E，CFU－F数量增加，辐射第14天的骨髓有核细胞数，脾脏指数，CFU－S明显增多，辐射第3，7，14天骨髓，脾脏bcl-2蛋白表达上升。结论：LJPS对小鼠造血功能辐射损伤具有治疗作用，其机理与调节骨髓，脾脏bcl-2蛋白表达有关。     

Investigation of higher-order cognitive functions during exposure to a high static magnetic field

Purpose:

To test for potential changes in higher‐order cognitive processes related to the exposure to a high static magnetic field.

Materials and Methods:

Twenty‐four healthy volunteers participated in two experimental sessions inside a 3 Tesla (T) magnetic resonance imaging (MRI) magnet. During one session the magnetic field was ramped down. The tasks consisted of six well‐established paradigms probing a variety of cognitive functions. Reaction times (RT) and accuracies (AC) were recorded for statistical analysis.

Results:

The overall performance was very similar in both sessions. Strong task‐specific effects (all P < 0.006) were consistent with previously published results. Direct comparisons of task‐specific effects between the two sessions (magnetic field on or off) remained insignificance for all paradigms (RT: all P > 0.196; AC: all P > 0.17; no corrections for multiple comparisons).

Conclusion:

The results did not indicate any apparent safety concerns with respect to cognitive performance in a static magnetic field of a typical whole‐body magnet. In addition, comparisons of cognitive effects from testing situations with and without exposure to high static magnetic fields can be considered valid. J. Magn. Reson. Imaging 2012;36:835–840. © 2012 Wiley Periodicals, Inc.     

Magnetic field correlation as a measure of iron‐generated magnetic field inhomogeneities in the brain

The magnetic field correlation (MFC) at an applied field level of 3 Tesla was estimated by means of MRI in several brain regions for 21 healthy human adults and 1 subject with aceruloplasminemia. For healthy subjects, highly elevated MFC values compared with surrounding tissues were found within the basal ganglia. These are argued as being primarily the result of microscopic magnetic field inhomogeneities generated by nonheme brain iron. The MFC in the aceruloplasminemia subject was significantly higher than for healthy adults in the globus pallidus, thalamus and frontal white matter, consistent with the known increased brain iron concentration associated with this disease. Magn Reson Med 61:481–485, 2009. © 2009 Wiley‐Liss, Inc.     

血小板第4因子对辐射损伤小鼠免疫功能的保护作用

目的：探讨血小板第4因子（plateletfactor4，PF4）对辐射损伤小鼠免疫系统的影响。方法：雄性BALB／c小鼠随机分为3组，第1组（单纯照射组）、第Ⅱ组（PF4保护组）、第Ⅲ组（正常对照组），第Ⅱ组在照射前26h及20h腹腔注射PF440μg／kg，全身一次性5Gy60Co—γ射线照射后瑞氏染色法计数外周血淋巴细胞百分数。胸腺、脾脏制成细胞悬液计数后，MTT比色法测定胸腺及脾细胞增殖能力。结果：第Ⅱ组小鼠外周血淋巴细胞百分数下降趋势较第1组明显减慢。胸腺、脾细胞计数，第Ⅱ组明显高于第1组。淋巴细胞增殖试验，第Ⅱ组与第1组相比，小鼠胸腺及脾细胞的增殖能力明显增强。结论：PF4对免疫系统有辐射保护作用，可明显增强辐射损伤小鼠的免疫功能。