混合稀土“常乐”对大鼠肾脏组织的氧化损伤

目的研究长期口服低剂量混合稀土"常乐"对大鼠肾脏自由基防御机能的影响。方法将清洁级Wistar大鼠随机分为对照组和5个不同剂量的混合稀土"常乐"组(0.1、0.2、2.0、10.0、20.0mg/kg),每组30只,雌、雄各半。混合稀土"常乐"组每日以灌胃方式给予上述不同剂量的混合稀土"常乐",对照组给予等量0.9%生理盐水。持续灌胃6个月后,检测肾组织中Cu-Zn超氧化物歧化酶(Cu-ZnSOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活力和脂质过氧化物(LPO)含量。结果与对照组比较,雄性大鼠20.0、10.0mg/kg组和雌性大鼠20.0mg/kg组Cu-ZnSOD和CAT的活力显著降低,差异有统计学意义(P<0.01),而GSH-Px的活力和LPO的含量显著升高,差异有统计学意义(P<0.01)。与对照组比较,雌性、雄性大鼠0.2、0.1mg/kg组Cu-ZnSOD的活力显著升高,差异有统计学意义(P<0.01);LPO的含量显著降低,差异有统计学意义(P<0.01);GSH-Px的活力差异无统计学意义(P>0.05)。结论较高剂量的混合稀土"常乐"导致大鼠肾脏脂质过氧化反应增强,清除自由基的能力下降;较低剂量的混合稀土"常乐"能抑制自由基的产生,降低体内过氧化物的含量,提高抗氧化酶的活力。     

血稀土负荷水平与居民健康状况关系的研究

目的：研究长期低剂量暴露居民血稀土负荷水平及其与健康的关系。方法：选择长期生活在江西寻乌离子型稀土矿区中心地带两行政村居民为暴露组，同县的非稀土矿区一行政村居民为对照组；用ICP－MS测血稀土负荷水平，同时检测反映机体健康状况的25项指标，用SPSS进行资料分析。结果：暴露组与对照组各调查328人和284人，平均血稀土总量分别为4．929和1．684μg/L，暴露组血稀土总量和15种稀土元素分量均显著高于对照组（P＝0．000）。血稀土元素中，含量最高的为La，其次为Ce、Nd，在暴露组和对照组中，3种元素之和分别占总量的68．72％和68．62％。暴露组与对照组相比，收缩压降低，脉搏加快，手提转速减慢，白细胞数、血红蛋白、红细胞压积、血小板、血钙、血糖等指标降低；其中血红蛋白、血小板、血钙、血糖低于正常值者较对照组显著增多。结论：暴露组血稀土负荷显著高于对照组，寻乌居民血稀土以La、Ce、Nd等轻稀土元素为主。居民的稀土暴露可能对血压、脉搏、神经反射、血细胞、血钙、血糖等有一定影响。     

稀土离子及其柠檬酸配合物诱导人红细胞的溶血作用

目的:研究稀土离子Ln3+及其柠檬酸根配合物[Ln(Cit)2]3-诱导人红细胞的溶血作用.方法:将不同浓度的Ln3+或[Ln(Cit)2]3-与人红细胞温育后,用分光光度法测定离心上清液中的血红蛋白浓度,计算相对溶血率H%.用外推法确定临界溶血浓度cH0.结果:14种稀土离子对人红细胞的临界溶血浓度cH0已经确定;发现[Ln(Cit)2]3-的H%～c关系曲线为非对称的"钟"型曲线,结论:稀土离子Ln3+具有较低的临界溶血浓度,这说明Ln3+与红细胞有较强的作用及细胞毒性.[Ln(Cit)2]3-诱导的人红细胞相对溶血率H%与稀土离子在介质中的物种分布有关.     

牛血清白蛋白、柠檬酸根和二价金属离子对人红细胞和兔小肠刷状缘囊泡摄取稀土离子的影响

目的:研究人红细胞(human erythrocytes,HRC)和兔小肠刷状缘囊泡(rabbit intestinal brush-border membrane vesicles,BBMV)对稀土离子Ln3+的摄入,以及牛血清白蛋白(bovine serum albumin,BSA)、柠檬酸根(Cit3-)和二价金属离子(M2+)的影响.方法:在溶液中有或无BSA (或Cit3-、Cu2+、Co2+、Zn2+、Cd2+、 Pb2+)的条件下,在HRC或提取的BBMV与Ln3+温育后,用ICP或ICP-MS测定HRC胞浆及膜或BBMV中Ln3+及M2+的含量.结果:被研究的Ce3+、Gd3+、Yb3+离子都能跨膜进入人红细胞,BSA 对Ce3+和Yb3+的跨膜输运有促进作用,但对Gd3+无影响.Pb2+、Cu2+、 Co2+、 Zn2+对HRC膜结合Ce3+量无影响,但Cu2+促进Ce3+跨膜进入细胞内.Ce3+促进细胞对Co2+摄入,但Co2+和Zn2+几乎完全抑制了Ce3+的跨膜输运.BBMV可以结合Ce3+、Gd3+、Lu3+和Cu2+、Pb2+、Cd2+ ; Cit3-抑制Ln3+的结合,抑制率随[Ln(Cit)2]3-稳定性增加而增加;Ce3+和Pb2+或Cd2+之间相互抑制其与BBMV的结合,但Cu2+促进Gd3+与BBMV的结合.结论:在HRC和BBMV对Ln3+和M2+的摄取中,Ln3+和M2+间存在着某些拮抗或协同作用,这些作用与Ln3+和M2+的性质有关.     

稀土Ce/Ag/ZnO对白色念珠菌的氧化应激抗菌机制研究

目的 研究稀土纳米复合材料Ce/Ag/ZnO对口腔白念珠菌的氧化应激抗菌机制。方法 通过细菌平板培养、绘制细胞生长曲线、扫描电子显微镜（SEM）观察以及氧化应激相关生化指标检测等实验方法，探究该材料对白念珠菌的抗菌机制。结果 稀土纳米复合材料Ce/Ag/ZnO作用于白念珠菌时，其MIC、MBC分别为0.156 mg/mL、0.313 mg/mL；SEM观察发现细菌皱缩塌陷、内容物泄漏，细胞膜严重破坏；细菌的活性氧（ROS）水平、脂质过氧化（LPO）程度以及过氧化氢酶（CAT）活力值均有明显升高（P＜0.05）。结论 稀土改性的纳米材料具有良好的抗菌效果，揭示其通过诱导白念珠菌内部产生氧化应激反应的抗菌机制，为未来该材料应用于义齿基托制作，预防口腔义齿性口炎发生提供理论支持。     

小儿哮喘缓解期治疗思路

小儿哮喘缓解期辨证应以培土生金、扶正治本为主,临床采用内外治相结合的综合疗法。通过缓解期的长期规范化治疗,可以有效地控制哮喘发作。同时加强患儿的饮食调适,体质调理,从而提高患儿的抗病能力,降低发病率,达到长期控制哮喘发作的目的。     

解放军总医院智慧医院建设初探

智慧地球战略已经给很多行业的信息化建设带来巨大影响。在医疗信息化领域,数字化医院也势必会逐步向智慧医院发展。解放军总医院已经开始着眼于未来,逐步调整信息化发展战略,向智慧医院迈进。     

Subchronic toxicity study of yttrium nitrate by 90-day repeated oral exposure in rats

Concerns regarding the adverse effects of long-term exposure to low levels of rare earth elements (REEs) from foods on human health have arisen in recent years. Nevertheless, no official acceptable daily intake (ADI) has yet been proposed for either total REEs or individual REE. In accordance with the Organization for Economic Co-operation and Development (OECD) testing guideline, the present study was undertaken to evaluate the subchronic toxicity of yttrium, a representative heavy REE with higher contaminated level in foods in China, to achieve a no observed adverse effect level (NOAEL) which is a critical basis for the establishment of an ADI. Yttrium nitrate was orally administered to rats at doses of 0, 10, 30 and 90 mg/kg/day for 90 days followed by a recovery period of 4 weeks. The following toxicity indices were measured: mortality, clinical signs, daily food consumption and weekly body weight; urinalysis, hematology, blood coagulation, clinical biochemistry and histopathology at the end of administration and recovery periods. No toxicologically significant changes were found in any yttrium-treated group as compared to the concurrent control group. Under the present experimental condition, the NOAEL in rats was thus set at 90 mg/kg for yttrium nitrate, i.e. 29.1 mg/kg for yttrium.     

从“土克水”角度认识“骨痿”

原发性骨质疏松症(primary osteoporosis,POP)是一种以骨量低下、骨微结构破坏,导致骨脆性增加、易发生骨折为特征的全身性骨病,在现代中医学中属于"骨痿"范畴,肾水亏虚是本病基础,并与肝木、脾土相关,除了补肾壮骨之外,黄帝内经创造性地提出了"治痿独取阳明"治疗大法,本文将通过五行"土克水"的角度重新梳理"骨痿"的病因病机,并在主流治疗方案之外创新性地提出了独特的治法治则,兹可作为现代中医治疗"骨痿"的一个重要补充。     

Structures of dolomite at ultrahigh pressure and their influence on the deep carbon cycle

Carbon-bearing solids, fluids, and melts in the Earth''s deep interior may play an important role in the long-term carbon cycle. Here we apply synchrotron X-ray single crystal micro-diffraction techniques to identify and characterize the high-pressure polymorphs of dolomite. Dolomite-II, observed above 17 GPa, is triclinic, and its structure is topologically related to CaCO₃-II. It transforms above 35 GPa to dolomite-III, also triclinic, which features carbon in [3 + 1] coordination at the highest pressures investigated (60 GPa). The structure is therefore representative of an intermediate between the low-pressure carbonates and the predicted ultra-high pressure carbonates, with carbon in tetrahedral coordination. Dolomite-III does not decompose up to the melting point (2,600 K at 43 GPa) and its thermodynamic stability demonstrates that this complex phase can transport carbon to depths of at least up to 1,700 km. Dolomite-III, therefore, is a likely occurring phase in areas containing recycled crustal slabs, which are more oxidized and Ca-enriched than the primitive lower mantle. Indeed, these phases may play an important role as carbon carriers in the whole mantle carbon cycling. As such, they are expected to participate in the fundamental petrological processes which, through carbon-bearing fluids and carbonate melts, will return carbon back to the Earth’s surface.