眼轴线后部眶容积增大与眼球内陷比值的测定研究

目的:通过测量眼眶爆裂性骨折伴有眼眶扩大患者的后部眼眶容积、观察眼球内陷出现的时间及程度,研究后部眶容积扩大与眼球内陷的关系比值,为病情预测和眶内填充手术提供比较精确的参考数据。方法:将96例患者按发病时间分为早期病例组(60例、受伤时间1周以内)和晚期病例组(36例、受伤时间3个月以上),早期组除进行后部眼眶容积测量外,分别于1周、2周、3周测定眼球突出度(相差>1mm为阳性),记录眼球内陷出现时间,用卡方检验进行统计学分析;晚期组测量后部眶容积增大值和眼球内陷量,对其相关性采用Pearson统计方法进行统计学分析,并得出回归方程及相关系数。结果:早期组60例患者中,(58.33%)例患者在1周内出现眼球内陷,4(880%)例在2周内出现内陷,3周时有5(388.33%)例呈现出内陷;2周时出现眼球内陷的例数与1周时有显著性差异(χ2=62.484,P<0.001),2周时出现眼球内陷例数与3周时无差异(χ2=1.563,P>0.05),1周时出现眼球内陷例数与3周时有显著差异(χ2=76.885,P<0.001),后部眶容积增大与眼球内陷的比值约为1.0,两者之间呈正相关(r=0.994,P<0.001),即后部眶容积每增加1ml,产生1.0mm的眼球内陷。结论:眼球内陷通常于伤后2周～3周出现,3个月时趋向稳定;后部眶容积增大与眼球内陷产生比值为1.0,呈正相关;后部眶容积扩大与眼球内陷比值可预测发生眼球内陷的可能性和程度,为手术矫正眼球内陷提供可靠、精确的参考,具有十分重要的临床指导意义。     

失血性休克大鼠肠上皮细胞线粒体DNA腺苷三磷酸酶6,8基因表达及线粒体功能的改变

目的　探讨失血性休克大鼠肠上皮细胞线粒体DNAATPase 6 ,8基因表达及线粒体功能的改变 ,为阐述休克肠道靶学说和线粒体能量代谢提供分子生物学基础。　方法　 2 4只Wistar大鼠随机分为休克前组和休克 1,2 ,3,4 ,5h组。采用RT -PCR方法观察线粒体ATPase 6 ,8mRNA量的改变。用透射电镜观察、生物体视学测量线粒体形态 ,用Clark氧电极测线粒体呼吸功能。　结果　失血性休克 1,2h ,ATPase 6 ,8基因表达增强 ,以后渐减弱 ,至休克 5h表达最低 ,ATPase 6 ,8基因表达分别降为正常的 6 9.3%和 78.4 % (P <0 .0 1和P <0 .0 5 )。失血性休克 2h和5h ,线粒体平均截面积、长径、面密度、体密度均显著增加 (P <0 .0 1) ,休克 5h时分别为休克前的2 .0 ,1.4 5 ,1.4 7,2 .2 2倍。休克 5h ,线粒体比表面和数密度分别下降 32 %和 2 4 % (P <0 .0 1和P <0 .0 5 ) ,嵴和基质破坏明显。失血性休克后肠上皮细胞线粒体呼吸控制率和氧化磷酸化效率比休克前显著降低 (P <0 .0 1)。　结论　失血性休克时大鼠肠上皮细胞线粒体DNAATPase 6 ,8基因表达下调 ,线粒体呼吸功能出现障碍 ,线粒体超微结构发生了改变     

APTT测定值和APTT测定值比率的临床应用价值探讨

目的;探讨APIT测定值(秒)和APIT测定值比率中哪一种是更稳定、更可靠的临床应用指标。方法:将同一标本采用法国STA-Compat全自动血凝仪以及两种手工法同时测定,比较同组标本不同方法的APTT测定值(秒)和APTT测定值比率。结果:手工法(一)与法国STA-Compact全自动血凝仅比较,如APTT值以秒表示,对照组、口服抗凝剂组及肝病组病人同组标本不同方法之间存在显著性差异(P<0.01,P0.10,P>0.50,P>0.05);手工法(二)与法国STA-Compact全自动血凝仪在对照组、口服抗凝剂组及白血病组的比较中,也获得类似的结果。结论:将APTT测定值(秒)转化为病人与对照APTT测定值比率报告,使不同方法结果间更具可比性。在APTT报告的标准化方面,建议将APTT和APTT测定值比率同时报告。     

中药安迪注射剂对人食管癌细胞的放射增敏作用

目的 :观察安迪注射剂 (Andi)对电离辐射生物学效应的影响。方法 :人食管癌细胞株 (ECA 10 9)在富氧 (空气 )和缺氧 (通 99 99%的高纯氮气 5 0min)条件下分别观察对照组、Andi组、60 Co γ线辐射和Andi +60 Co γ线辐射 4组细胞形态 (光镜 )、细胞倍增时间 (TD)、存活率 (SR)及集落存活分数 (SF)。结果 :光镜下可见Andi组、辐射组、Andi+辐射组癌细胞变性、坏死、凋亡 ,以Andi +辐射组为最显著。MTT法测定对照组、Andi组、60 Co γ线辐射和Andi+60 Co γ线辐射四组缺氧细胞的TD(% )分别为 4 6 12 ,118 72 ,6 2 81,171 0 2h ,SR分别为 10 0 % ,4 2 % ,86 % ,30 % ;各治疗组与对照组比较TD 和SR均相差显著 (P <0 0 5 )。方差分析显示 ,辐射在富氧 (F =90 19,P =0 0 0 0 1)和缺氧 (F =37 0 9,P =0 0 0 0 3)时均为SF的影响因素 ;Andi仅在缺氧时对SF是有意义的影响因素 (F =2 9 0 4 ,P =0 0 0 0 7) ,与60 Co γ线辐射合用对缺氧细胞SF的影响具有协同作用 (F =11 37,P =0 0 0 98)。用单靶多击模型拟合数据分析 ,Andi的放射增敏比 (SER)为 1 5 ,相对敏化效应 (RSE)为 5 5 %。结论 :Andi对缺氧ECA 10 9细胞具有明显的细胞毒和放射增敏作用。     

Signal-to-noise ratio effects in quantitative cerebral perfusion using dynamic susceptibility contrast agents.

Theoretical and simulation evidence is presented in support of the idea that the optimal manner of determining blood flow from MR perfusion studies is not necessarily obtained by setting experimental conditions to maximize either the arterial input or the measured tissue concentration level for a particular echo time (TE). The noise power in the contrast concentration curve is associated with its peak because of the nonlinear relationship between the contrast concentration and MR signal intensity curves. The optimum signal-to-noise ratio (SNR), SNR(C), for a particular contrast concentration curve can be obtained when the experimental concentration level and TE are adjusted to produce an MR intensity curve whose signal loss is 63% of the precontrast MR signal intensity. It is demonstrated that the stability of the singular valued decomposition (SVD) deconvolution approach to determine blood flow parameters is increased when the tissue curve maximum signal loss is in the range of 40-80%. The accuracy and stability of the SVD-determined blood flow parameters are affected by deviations from these optimum conditions in a manner that depends on the mean transit time (MTT) associated with the residue function. It is recommended that the experimental TE value be set so that neither the tissue nor the arterial curves are placed a region of rapidly deteriorating SNR(C).     

Heroin self-administration in rats under a progressive ratio schedule of reinforcement

Heroin self-administration behavior under a progressive ratio (PR) schedule of reinforcement was evaluated in rats. The schedule was designed to restrict drug intake, minimize opiate dependency, and quantify the number of responses emitted (final response ratio) in order to receive a limited number of heroin infusions. Final ratios were found to be stable and did not increase with chronic (31 days) PR reinforcement. The ability of the PR schedule to detect changes in heroin reinforcement was demonstrated by evaluating the effect of naltrexone pretreatment and unit dose alteration on final ratios. Naltrexone (0.4 mg/kg) reduced final ratios and an inverted U dose-response relationship was established for the unit heroin doses 12.5–100 µg/injection. Maximal final ratios occurred with 50 µg/injection heroin reinforcement. This PR schedule may provide a useful method for evaluating the effects of pharmacological manipulations or lesions on opiate reinforcement.     

Self-administration of GBR 12909 on a fixed ratio and progressive ratio schedule in rats

Intravenous self-administration of GBR 12909, an indirect dopamine agonist, was examined on a Fixed Ratio (FR 1) and a Progressive Ratio (PR) schedule of reinforcement in rats. Subjects were first trained to self-administer cocaine (1.5 mg/kg/inj) during daily 5 h sessions, after which GBR 12909 (0.187–1.5 mg/kg/inj) was substituted. On the FR 1 schedule, the inter-infusion interval for GBR 12909 self-administration was directly related to dose and was approximately three times longer than that established for equivalent doses of cocaine. Breaking points on the PR schedule were comparable for GBR 12909 and cocaine self-administration. The data indicate that, compared to cocaine, GBR 12909 has a longer duration of action and a similar reinforcing efficacy.     

水稻亚种间杂种优势利用研究

本试验探讨了华南双季稻区利用亚种同杂种优势的特点和问题,结果表明:当前,两系亚种问杂种一代主要存在的问题是结实率低和谷草比低;籼粳交杂种易受环境条件的影响;每穗实粒数和单株有效穗数是决定单株产量的重要因子;每穗实粒数增加的关键在于结实率的提高,本文还就提高结实率和谷草比等问题提出了意见。     

pH指示剂吸收度比值法测定盐酸乙胺丁醇的含量

本文报道pH指示剂吸收度比值法测定盐酸乙胺丁醇的含量。该法采用指示剂为0.05%茜素黄R,测定波长374nm和500nm;标准液为0.1mol/L NaOH;仪器为WFZ-800D_2型分光光度计。测得三批盐酸乙胺丁醇的含量分别为99.5±0.04%,99.4±0.05%和99.6±0.03%.同时与药典法比较,结果一致。