用高分辨G带和人工细菌染色体荧光原位杂交技术分析中国儿童孤独症患者的染色体改变

目的 检测中国儿童孤独症患者的特征性染色体改变。方法 应用高分辨G带和人工细菌染色体(bacterial artificial chromosome，BAC)荧光原位杂交(flourescence in situ hybridization，FISH)分析68例中国儿童孤独症患者的染色体改变。结果 用G带分析观察到有染色体改变的4例患者，分别为1例t(4；6)(q23-24；p21)、1例21p 和2例9号染色体臂间倒位。BAC FISH进一步证实易位病例，而且更精确[t(4；6)(q25-26；p21-1)]；涉及7号、15号、2号染色体的BAC FISH均未观察到文献中报道的染色体改变；而9号染色体的臂间倒位和21p 因无BAC克隆而无法证实。结论 用G带和BAC FISH发现少数中国孤独症患者有染色体改变，但远没有文献中报道的10％～48％那么高。BAC FISH有助于精确地确定染色体易位断裂点。     

Positive correlation between aortic valve pressure gradient and mitochondrial respiratory chain capacity in hypertrophied human left ventricle

Summary The effect of chronic left ventricular pressure overload on the activities of mitochondrial respiratory chain enzymes was investigated in myocardial biopsies from the left ventricular apex of 13 patients undergoing aortic valve replacement for aortic valve stenosis. Transvalvular pressure gradients measured by left-sided heart catheterization ranged from 52 to 100 mmHg. The specific activity of mitochondrial respiratory chain enzyme complexes I + III (antimycin A sensitive NADH cytochrome c oxidoreductase) and the myocardial concentrations of coenzyme Q₁₀ (CoQ₁₀) increased significantly (P < 0.05) with increasing aortic valve pressure gradient. In contrast, the specific activities of complex IV (cytochrome c oxidase), succinate dehydrogenase, and citrate synthase, a mitochondrial matrix enzyme, showed no significant correlation with the pressure gradient. Since (CoQ₁₀) is the rate-limiting compound of the activity of complexes 1+111 but not of cytochrome c oxidase, succinate dehydrogenase, or citrate synthase, these data suggest that the increase in the activity of complexes I+III is due to the increase in (CoQ₁₀) content.Abbreviations CoQ coenzyme Q - CoQ₉ coenzyme Q₉ - CoQ₁₀ coenzyme Q₁₀ - SDH succinate dehydrogenase - NCP noncollagen protein     

A synthetic leaflet heart valve with improved opening characteristics

A new geometry for the design of polyurethane leaflet heart valves has been investigated. The geometry termed the ‘alpharabola’ has a radius of curvature that increases from the centre of the leaflet at the free edge towards the base of the valve and perimeter of the leaflet. The hydrodynamic function and leaflet opening characteristics of the new valve design have been compared to a valve with a spherical leaflet geometry using the same material. The pressure and flow required to open alpharabola leaflets in steady flow tests was markedly lower than for spherical leaflets. Under pulsatile flow conditions with the valve leaflets fully open, the pressure drop across the alpharabola and spherical leaflets was similar, but much lower than in a porcine bioprosthesis. High speed photography showed that the alpharabola leaflets opened in less than 30 ms with the leaflet opening initiating in the base of the leaflet where the radius of curvature was larger. The synthetic leaflet valve has demonstrated short term durability in accelerated fatigue tests to 100 million cycles.     

In vitro velocity measurements down strem from the lonescu-Shiley aortic bioprosthesis in steady and pulsatile flow

Velocity measurements were made in vitro using laser Doppler anemometry (LDA) downstream from an lonescu-Shiley (IS) bioprosthetic aortic heart valve. Velocity measurements were made in both steady and pulsatile flow. A systematic, flow mapping approach to the measurement methodology showed that the IS valve generated a large jetlike flow constriction. The acceleration ratio, defined as the maximum mean velocity for the IS valve divided by that for no valve obstructing the flow, was as high as 2·4 for steady flow and 2·6 for pulsatile flow. It was concluded that the IS valve generated a flow quite unlike that observed by other in vestigators for the natural human aortic valve, after which the leaflet design of the IS valve was modelled. In addition, a comparative analysis of steady and pulsatile results was undertaken. It was found that the pulsatile flow results for the systolic ejection interval could be divided into three phases, denoted early, mid, and late systole, as defined by the flow structure at the data plane location. Only during midsystole were the pulsatile flow results approximated by the steady flow results. Also, it was found that the magnitude of the flow disturbance measured in steady flow tended to be an upper bound on that measured for pulsatile flow.     

肱骨远端的解剖观测与肱骨假体的设计

目的:为临床肱骨远端假体的设计与安放提供相关数据。方法:测量120块(男35对、女25对)成人干燥肱骨远端相关结构,对所测得结果用SPSS软件处理。结果:(1)肱骨远端前倾角和肱骨滑车外旋角,男女分别为(35.78±5.12)°、(36.33±5.06)°和(5.35±1.13)°、(5.55±1.22)°。(2)内上髁至外上髁最大宽度、滑车最内侧缘至小头最外侧缘宽度、肱骨滑车和肱骨小头宽度男女分别为(58.92±4.03)、(55.75±3.85);(45.34±3.15)、(42.18±3.01);(24.82±1.74)、(21.78±1.51)和(17.69±1.23)、(16.39±1.21)mm。(3)肱骨滑车和肱骨小头最大矢径男女分别为(23.35±2.06)、(23.13±2.15)和(19.47±1.38)、(19.13±2.19)mm。男女之间和左右之间各测量数据无显著性差异(P>0.05)。个体间有较大差异。结论:肱骨远端各项目的测量值,可供设计与安放肱骨假体提供解剖参数。     

Blastocoele collapse by micropipetting prior to vitrification gives excellent survival and pregnancy outcomes for human day 5 and 6 expanded blastocysts

BACKGROUND: Manual puncture of the trophectoderm of human blastocysts with a needle before vitrification increases their survival rate, but the embryos take a long time to re-expand. This study examined whether causing human blastocysts to collapse by manual pipetting before vitrification would allow more rapid re-expansion and improve pregnancy rates. METHODS: After embryo transfer in IVF cycles, surplus embryos that developed to the expanded blastocyst stage were placed in cryoprotectant and then artificially shrunk by mechanical pipetting with a fine hand-drawn glass pipette slightly smaller in diameter than the blastocyst. The shrunken embryos were placed in a small volume of vitrification solution and plunged into liquid nitrogen on a cryotop. The blastocysts were thawed by warming and then dilution in 1 mol/l sucrose. RESULTS: Of 49 expanded vitrified blastocysts, 48 (98%) re-expanded within 3 h after warming. Following transfer (48 blastocysts in 28 cycles), 14 women (50%) became clinically pregnant, and the implantation rate was 33% (16/48). Eight healthy babies have been born in six deliveries, and the other eight pregnancies are ongoing. To date, there have been no spontaneous abortions. CONCLUSIONS: The results suggest that artificial shrinkage with pipetting is a simple and effective technique to assist successful cryopreservation of expanded blastocysts by vitrification.     

不同位置植入SMH人工腰椎间盘对小关节应力分布的影响

目的:通过三维有限元方法研究正常椎间盘、SMH人工腰椎间盘前置、中置和后置四组模型中小关节的应力分布情况,探讨不同位置植入SMH人工腰椎间盘对小关节应力分布的影响。方法:建立正常腰椎间盘、人工SMH腰椎间盘前置、中置和后置的三维模型,然后模拟腰椎节段的运动,进行小关节应力分布的比较研究。结果:与正常L4/5椎间盘模型相比,除SMH人工腰椎间盘前置模型前屈时比正常模型小关节应力小外,其余运动时SMH人工腰椎间盘前置、中置和后置模型中小关节的应力均高于正常腰椎间盘组,但后置SMH人工腰椎间盘组则相对较小。结论:SMH人工腰椎间盘后置可以更好地预防小关节的退变;人工椎间盘植入位置的不同对人工腰椎间盘术远期疗效的预测具一定的作用。     

组织工程化心脏瓣膜的研究进展

心脏瓣膜置换术是外科治疗瓣膜性心脏病的主要方法，但目前临床应用的人工瓣膜的远期效果尚不满意。近年来，随着组织工程学技术的进展，利用培养的自身组织细胞种植于支架材料表面，体外重新构建理想的心脏瓣膜植物日益成为研究热点。本文简述了心脏瓣膜工程的定义，细胞支架材料的选择，种子细胞的培养、种植方法以及组织工程化心脏瓣膜的评估，并指出下一步研究中尚需解决的问题。     

肠腔静脉人工血管C型分流术的远期疗效观察

目的 探讨肠腔静脉C型分流术治疗食管胃底静脉曲张破裂出血的远期疗效。方法 对成阳市中心医院肝胆外科1992年以来施行的36例肠腔静脉C型分流术的临床资料进行总结分析。结果 36例患者术后门静脉压平均下降1．51kPa，胃镜检查食管静脉曲张均有明显减轻或消失。术后再出血率5．6％，肝性脑病发生率8_3％，术后1年、3年、5年及10年的生存率分别为97．2％、93．3％、89．3％及66．7％。结论肠腔静脉C型分流术手术适应证广，操作简单，近、远期疗效满意，适于推广。     

叶轮泵式全人工心脏的结构设计及流体力学特性

目的通过模型样机研制和流体力学特性测试．探索以叶轮式血泵为结构基础的新型可完全植入的全人工心脏。方法全人工心脏模型样机分为左心泵和右心泵2个基本单位。2血泵均采用叶轮泵．共同设置在球形外壳中。2半球形外壳由高分子材料经激光快速成型制成．球形腔内设置固定左右心泵后对合为球形外壳．表面由医用聚氨酯橡胶涂层，直径55mm，总质量150g左右。在体外模拟循环台上对左心泵和右心泵的流体力学特性进行测试．主要观测指标为泵的转速、输出压力、流量、能耗和效率。模拟循环装置由模拟左右心房、血泵、阻力调节器、流量计串联组成，采用30％甘油水溶液作为循环介质。通过调节阻力测定特定泵转速下压力和流量。结果体外模拟测试表明全人工心脏模型样机可满足血液动力学基本要求，左心泵在9000-13000r／min转速条件下可以达到5-7L／min流量和13．3kPa（100mmHg）的压力输出，右心泵在约1／2左心泵转速和4．00kPa（30mmHg）后负荷下达到相似流量．可分别满足体、肺循环的要求。在该工作负荷条件下，2血泵的总效率约为14％。结论轴流泵作为人工心脏的血泵单位．流体力学特性可达到全人工心脏的基本要求．