内毒素所致DIC时血小板胞浆Ca^2＋浓度变化的研究

本实验观察内毒素在体外对兔血小板胞浆游离钙浓度[Ca~(2+)]i的作用以及用二次注射内毒素法复制DIC模型时对[Ca~(2+)]i的影响。结果表明静息血小板[Ca~(2+)]i为112±24 nM,内毒素可直接作用于血小板,使[Ca~(2+)]i呈剂量依赖性升高。内毒素致DIG时(Ca~(2+)]i可升高三倍。结果提示内毒素可能是通过升高血小板[Ca~(2+)]i而激活血小板。血小板的激活可能是导致DIC的重要发病机制之一。     

小鼠胸腺基质细胞株MTECB的细胞学特性

用免疫组织化学和透射电镜技术对本室所建立的小鼠胸腺基质细胞株ＭＴＥＣＢ进行了细胞学鉴定。免疫组织化学观察显示：４０ｋＤ、４５ｋＤ角蛋白和波形蛋白呈现强阳性，５２ｋＤ，５４ｋＤ，５８ｋＤ角蛋白和Ｓ－１００蛋白呈现阴性。电镜下见到，具有桥粒和张力丝结构，含较多的囊泡和髓样体，发达的高尔基复合体和线粒体。另外ＭＴＥＣＢ还表现为酸性磷酸酶、碱性磷酸酶、非特异性酯酶弱阳性。据此我们认为ＭＴＥＣＢ为上皮细胞来     

正交偏光镜下人体胆汁液晶光学性质的研究

本文报导了在正交偏光镜下，对人体胆汁液晶的光学性质的研究，结果表明，胆汁液晶是一种非均质体，在正交偏光镜下，呈现出特殊的干涉图样和四次消光现象，光性符号是单轴正性的，干涉色级是一级灰白，双折射率Δｎ＝０．０１１－０．０１７。     

Soil microbial activities and carbon and nitrogen fixation

Soil microbial activity that reflects microbiological processes of soil microorganisms is the potential indicator of soil quality, as plants rely on soil microorganisms to mineralize organic nutrients for growth and development. Soil microorganisms also process plant litter and residues into soil organic matter, a direct and stable reservoir of carbon and nitrogen that consists of living and dead organic materials subject to rapid biological decomposition. In natural systems, the action of soil microorganisms is a major determinant of efficient nutrient cycling. This paper reviews the current state of knowledge on the fate of soil microorganisms in terms of carbon and nitrogen fixation.     

骨髓基质细胞和内皮细胞联合种植构建组织工程化骨的初步研究

为阐明骨髓基质细胞和内皮细胞联合种植在生物复合材料上构建组织工程化骨 ,在促进成骨过程、加速局部血管生成中的作用 ,将大鼠骨髓基质细胞和人脐静脉内皮细胞联合种植在左旋聚乳酸 /β-磷酸三钙 (PL L A/β- TCP)多孔复合支架材料上作为实验组 ,仅种植骨髓基质细胞在该材料上作为对照组。将此种有活细胞的复合材料种植于裸鼠大腿后侧肌袋内 ,分别于种植后 1、4、8、12、16周处死动物 ,取出复合材料 ,行组织学检测 ,并用图像处理技术计算实验组和对照组的成骨面积百分比和材料面积百分比 ,观察其变化规律。结果显示 :实验组成骨面积百分比增加比对照组明显加快 ,而材料面积百分比减少比对照组迅速 ;其内毛细血管网形成情况也要明显优于对照组。表明骨髓基质细胞和内皮细胞联合种植于支架材料构建组织工程化骨不仅有利于成骨作用 ,促进新生骨区内部血管网形成 ,还有利于复合材料的降解吸收 ,这在构造组织工程化骨过程中具有重要意义。     

自制IPS-Empress2铸瓷快速包埋材料物理机械性能表征

为降低IPS-Empress2铸瓷修复成本,研制了国产化包埋材料,以取代昂贵的进口专用包埋材料.对自制包埋材料的物理机械性能进行表征,与进口材料进行比较和统计分析,并用扫描电镜观察两种材料表面形貌的异同点.结果显示:自制包埋材料的凝固时间为9 min,烧结前密度为1.813 g/cm3,烧结后密度为1.402 g/cm3,开口孔隙率38.1%,凝固2 h后抗压强度和烧结后抗压强度分别为5.42 MPa和8.37 MPa,且耐火度在1000 ℃以上,高于铸造温度(920℃).与进口材料相比,自制包埋材料凝固时间更短,烧结前密度、凝固2h后抗压强度和烧结后抗压强度更高;开口孔隙率、烧结后密度和耐火度无统计学差异.扫描电镜观察显示两种材料结构相似,但自制材料的晶体尺寸略小于进口材料.可见自制包埋材料的主要物理机械性能指标接近或优于进口专用包埋材料,具有良好的临床应用前景.     

Enhanced osteoinduction by intramuscular grafting of BMP-beta-TCP compound pellets into murine models.

The osteoinductive effects of bone morphogenetic protein (BMP, derived from murine osteosarcoma) were studied with regard to its use combined with beta-tricalcium phosphate (beta-TCP). BMP and beta-TCP were molded into pellets by the "pressure method", originated by us and transplanted to ddY mice. Control mice received interdorsal muscular implantations of either the BMP or beta-TCP pellets. The animals were sacrificed 1, 2 and 3 weeks after grafting, for radiological, histochemical, and ultrastructural observations. The BMP-beta-TCP compound pellets induced faster cartilage and bone formation, whereas these activities were slower when pellets made solely of BMP were used. The beta-TCP pellets demonstrated no osteoinductive properties. Observations revealed two types of beta-TCP resorbing multinuclear giant cells. One was osteoclastic, expressing calcitonin receptors, having numerous mitochondria and ruffled border-like structures; the other was not osteoclastic in nature. In animals grafted with the compound pellets, a great number of osteoclastic cells gathered on the pellets, much earlier than those grafted with the pellets made of BMP alone. Then, osteoblastic bone formation over the cement lines followed an osteoclastic resorption of both beta-TCP and newly formed bone. In contrast, BMP induced few osteoclastic cells, resulting in slower bone coupling. Furthermore, the faster bone formation induced by the compound pellets seemed to be associated with the presence of beta-TCP. Porous by nature, beta-TCP would entrap BMP within its micropores, and thus, the intrinsically diffusible BMP is retained and its action consequently prolonged. In addition, the compound pellet offered increased surface contact between BMP and mesenchymal cells. Therefore, BMP-beta-TCP compound pellets induce cartilage and bone formation more rapidly than does BMP alone.     

高速线扫描OCT的可行性与光学成像特性的研究

光学相干层析成像（0cT）是一种迅速发展的非侵入式、高分辨率医学层析成像技术。由于传统时域点扫描方式的OCT系统的成像速度慢，难以用于活体的实时成像。介绍了基于线扫描方式的时域OCT系统，这种扫描方式可以无需横向扫描直接得到二维层析图像。为验证基于线扫描方式的时域OCT系统的可行性及得到其设计基本参数，借助Zemax光学设计软件模拟该系统的干涉效果，分析线扫描时域OCT的成像特性。研究表明，这种线扫描OCT在3mm的横向扫描宽度时，可以比传统点扫描方式快二百余倍。     

亚低温减少大鼠短暂性全脑缺血后皮质iNOS诱导的神经元凋亡

为研究亚低温对大鼠脑缺血再灌注后皮质iNOS表达、NO产生及神经元凋亡的影响及探讨亚低温的神经保护机制,用大鼠短暂全脑缺血模型,采用Nissl染色观察存活神经元、免疫组化法检测iNOS、硝酸还原酶法检测NOx-水平和TUNEL染色结合电子显微镜观察检测凋亡神经元。结果显示:常温缺血组额叶皮质iNOS表达、NOx-水平增高,出现凋亡神经元;低温缺血组iNOS表达、NOx-水平明显低于常温缺血组,未检测到凋亡神经元。上述结果提示,脑缺血后iNOS来源的NO参与了神经元的凋亡过程,亚低温可减少大鼠短暂性全脑缺血后iNOS诱导的神经元凋亡。     

特殊类型的小儿变态反应性亚败血症

变态反应性亚败血症(SA)是一种少见疾病，临床表现复杂多样，其基本特征是：①长期反复的弛张热：②一过性皮疹；⑧关节肿痛；④血培养阴性；①对抗生素治疗无效而对激素有反应．本文介绍SA几种特殊的临床峩现，包括：突出的中枢神经系境症状．大量的心包积掖，变应性血管炎，血液系境表现为骨髓增生异常综合征(MDS)并最终转变为白血病．等等，这些特殊的表现极为罕见，但它们一且成为突出的临床特征．本病的诊断将变得十分困难认识这些特殊的表现，对正确毋断本病具有较大价值的。本文就这具有特殊表现的SA的临床特征和诊断进行分析和探讨。