Measurement of brain perfusion by volume-localized NMR spectroscopy using inversion of arterial water spins: accounting for transit time and cross-relaxation.

The theoretical model for perfusion measurement by NMR using arterial labeling of endogenous water is extended to include the effects of transit time and cross-relaxation of tissue water with macromolecules. Water magnetization in rat brain is monitored using the STEAM method to simultaneously determine the transit time, magnetization transfer rate constant, and perfusion. The results show that the transit time in rat brain is quite short, and thus its effect on perfusion measurement is small. It is also demonstrated both theoretically and experimentally that the steady-state effects of cross-relaxation with macromolecules on perfusion measurement are accounted for by a proper control experiment.     

Activation of phospholipase D by platelet-derived growth factor (PDGF) in rat C6 glioma cells: possible role in mitogenic signal transduction.

The effects of platelet-derived growth factor (PDGF) on phospholipase D (PLD) activity and deoxyribonucleic acid (DNA) synthesis in rat C6 glioma cells have been investigated. Pretreatment of serum-starved C6 cells with PDGF results in enhanced choline production and the phosphatidylethanol (PEt) formation in the presence of ethanol, indicating the activation of PLD acting on phosphatidylcholine (PC). The dose-response curve for choline generation and DNA synthesis were comparable. In addition, the effects of PDGF on both PEt formation and [3H]thymidine incorporation into acid-precipitable material was blocked by the potent protein kinase C (PKC) inhibitor 1-(5-isoquinolinesulphonyl)-2-methylpiperazine (H-7) but not by N-(2-guanidinoethyl)-5-isoquinolinesulphonamide (HA1004), a relatively weak inhibitor of PKC, suggesting that PDGF plays an important role as a positive regulator of glioma cell growth via a PLD-mediated mitogenic signal transduction cascades, which depends largely on the activation of PKC.     

重度联合免疫缺陷小鼠的繁育及其应用初报

应用带过滤罩的透明鼠在层流柜内繁育Ｔ和Ｂ淋巴细胞缺失的重度联合免疫缺陷（ｓｃｉｄ）小鼠获得成功，１９９３年５月至１９９４年４月，共繁育ｓｃｉｄ小鼠２２１只，寿命均超过１２个月。平均每窝产仔数为５．５只，显著低于对照组ＢＡＬＢ／ｃ小鼠，不育率为１４．９％，离乳率为８８．２％，与ＢＡＬＢ／ｃ小鼠相比均无明显差异。ｓｃｉｄ小鼠４～１０周龄的体重与同龄ＢＡＬＢ／ｃ小鼠相比无明显差异，微生物学检测均符合ＳＰ     

71例初产妇前置胎盘与人工流产相关性分析

目的:探讨初孕人工流产与再孕后前置胎盘发生率的相关性。方法:对1992年1月～2001年12月住院分娩的4046例初孕人工流产进行回顾分析,对影响前置胎盘发生率的因素进行x~2检验。结果:初产妇前置胎盘发生率为1.75％;人工流产次数越多,末次人工流产术后至本次妊娠时间间隔越短;人工流产术后有生殖道感染史者,前置胎盘发生率明显增高。结论:人工流产术是前置胎盘的高危因素,应加强育龄妇女的生殖健康宣传和教育,做到有计划受孕,减少非意愿妊娠的发生。     

经颅多普勒观察消炎痛治疗兔急性脑外伤的实验研究

为探讨消炎痛（ＩＤＴ）对急性实验性颅脑损伤后脑血流速度的早期影响，采用直接打击法建立具有临床闭合性颅脑损伤特点的兔急性实验性颅脑损伤模型。在该模型的基础上，静脉注射ＩＤＴ（４ｍｇ／ｋｇ），应用经颅多普勒超声（ＴＣＤ），观察其对大脑中动脉（ＭＣＡ）血流速度的影响，并结合颅内压（ＩＣＰ）监护，综合评定消炎痛在脑外伤治疗中的作用。结果表明：ＩＤＴ对脑外伤后脑血流速度有明显影响（Ｐ＜０．０５）。具体表现为ＭＣＡ收缩期血流速度（Ｖｓ）和血流速度时间平均值（ＴＡＭ）降低，而舒张末期血流速度（Ｖｄ）保持相对恒定。随着脑血流速度的下降，动物ＩＣＰ升高的速度及幅度也明显低于对照组。结果提示：ＩＤＴ在不影响脑氧代谢的基础上，可以减少脑血流量，从而有效地控制ＩＣＰ升高，改善脑外伤的预后。     

硫酸多糖对体外人脐静脉内皮细胞损伤的保护作用

研究表明,硫酸多糖体外对多聚阳离子和氧自由基损伤的人脐静脉内皮细胞有保护作用。肝素、硫酸软骨素A抗多聚阳离子损伤作用比同浓度低分子肝素和甘糖酯强。肝素、硫酸软骨素A、甘糖酯抗氧自由基损伤作用优于同浓度低分子肝素。结果显示硫酸多糖有保护血管内皮的作用,其作用可能与所带阴离子基团有关。     

人体液中喷布洛尔及其代谢物的GC/MS分析

用气相色谱一质谱联用(GC-MSD)系统分析方法检出了人尿中喷布洛尔的6个羟化代谢物,用Scp-Pak柱提取的方法检出了人血浆中的原型药物。并从分子结构上对此药物的代谢途径进行了研究。尿中提取和血中提取的回收率分别为90.83.%和85.88%,Gc-MSD的检测限为5pg。本方法适用于运动员兴奋剂的系统检查。     

改良锂清除试验──一种在人体测量肾小管钠转运功能的方法

在常用的七小时锂清除试验方法基础上，我们观察了实验开始后第四小时血清理浓度与血清理代表浓度的关系，二者密切相关，ｙ＝０．９０９ｘ＋０．１７，ｒ＝０．９５２，Ｐ＜０．００５。应用此方程式，可将原方案中两次取血减为一次。另外，我们还总结出正常人锂清除率和锂排泄分数的参照值分别为８．４～３１．６ｍｌ／ｍｉｎ和９．６％～２６．３％。     

肺结核线索调查中X线胸透的代价和效益试评

用热释光剂量计测试了受检者胸透体表照射量，结果表明受检者体表照射量符合对数正态分布，几何均值为０．１９ｍＣ·ｋｇ－１，高于一般体检胸透照射量水平。根据危险度系数，估算出由此造成的辐射诱发恶性肿瘤危险度，男女分别为３．５５×１０－６和４．０５×１０－６，后裔遗传疾患的危险度均为４．０×１０－８，由此估计该次实践造成的人均寿命缩短时间为０．５２ｈ·人－１。利用江苏省结核病的患病率、死亡率、化疗治愈率估算出由此次实践带来的人均寿命延长时间为４５．８ｈ·人－１。