血清低密度脂蛋白胆固醇直接测定与Friedewald公式计算结果比较

采用聚乙烯硫酸（ＰＶＳ）沉淀法测定血清低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）值，同时应用Ｆｒｉｅｄｅｗａｌｄ公式计算ＬＤＬ－Ｃ含量，并对两法结果进行比较分析，提出当甘油三脂（ＴＧ）＜４．５２ｍｍｏｌ／Ｌ时，Ｆ公式计算法可代替ＰＶＳ法，当ＴＧ＞４．５２ｍｍｏｌ／Ｌ时，不宜用Ｆ公式计算ＬＤＬ－Ｃ的值。     

补体对免疫沉淀的抑制作用与小儿肾脏疾病的关系

以辣根过氧化物酶（PO）和抗-PO作为免疫沉淀中的抗原和抗体，用光电比色法，对78例小儿肾脏疾病血清补体对免疫沉淀的抑制作用（IIPC）进行了研究，并同时检测补体成分C3、C4。结果，正常对照IIPCOD值为0．505±0．085，急性肾小球肾炎（0．137±0．108）显著降低（P＜0．001）；慢性肾小球肾炎（0．470±0．053）改变不明显（P＞0．05）；肾病综合征（0．401±0．038）明显低下（P＜0．05）。IIPC低下的发生率依次为急性肾小球肾炎（83％）、肾病综合征（43％）、慢性肾小球肾炎（32％）。表明小儿肾小球疾病时IIPC大多降低并与疾病的活动性有关。因此认为IIPC低下在肾脏病的发生和发展中起一定作用。     

阳江高本底地区居民健康流行病学调查数据库与统计分析方法

目的 研究应用计算机数据库技术及先进统计分析方法,对阳江高本底地区10多万人20余年的健康随访研究资料和剂量学调查资料进行储存、管理和分析。方法 通过调研和比较分析,确定采用Foxbase系列数据库管理系统按专题建立数据库,借助于ID号实现记录连接；一般统计分析由SAS完成；交叉分组人年列表由Epicure中的Datab完成；癌症相对危险分析用AMFIT程序。结果 建立了40MB的各专题研究库,主要包括：10余万人的人口学数据库(1979～1995)、1.2万人的死因数据库(1979～1995)和526个村庄6783户、5273人的剂量数据库。提出了动态群组研究资料(1979～1986)与固定群组研究资料(1987～1995)的合并方法：首选方法是建立假想的基于记录连接的以1979年为起点的(固定)群组。另一方法是将不同阶段群组研究的人年表分层直接相加。计算了每个成员基于卧室内、起居室内、室外村平均剂量率与性别-年龄别居留因子的累积剂量。完成了以性别、atainedage、随访年代及剂量交叉分组的人年列表,对癌症死亡资料(1979～1990)进行了危险分析。结论 应用计算机数据库管理系统与统计分析技术使阳江高本底地区研     

盐析法提取卵黄免疫球蛋白的研究

为了确定盐析法提取特异性卵黄免疫球蛋白的最佳盐浓度，采用SDS—PAGE鉴定IgY的纯度，用RID测定IgY含量，间接ELISA法检测特异性卵黄抗体的活性。结果表明：用饱和度50％的硫酸铵盐析一次，再用140g／L的硫酸钠溶液盐析，可以获得469，6的回收率和77％的纯度。盐析液经超滤膜包超滤后制得的冷冻干燥制品，保持了完整的抗体结构和良好的抗体活性。这一结果为IgY的进一步分离纯化奠定了基础。     

Experiences with risk estimates for carriers of chromosomal reciprocal translocations

The risk estimates for individual carriers of ten different familial reciprocal translocations detected among 500 couples with reproductive failures are presented. These were established by application of the empirical data analysed by Stengel-Rutkowski et al. (1988) and the guidelines given in Stene & Stengel-Rutkowski (1988). Different risks were estimated for unbalanced offspring at birth or at second trimester prenatal diagnosis for abortions, or stillbirths/early deaths. These risk estimates varied considerably from translocation to translocation. Carriers of five translocations had risks for offspring with single-segment imbalances. The birth risk figures ranged from 0.1% to 13.8%. Carriers of five other translocations had risks for double-segment imbalances with birth risks ranging from 0% to 3.2%. The estimated risk figures were independent of the method of ascertainment. Among the parents of the index cases we found nine maternal carriers and only one paternal carrier. This presentation illustrates the need for individual risk counselling of each carrier with reciprocal translocation regarding further family planning.     

北京市区大气细菌粒子的沉降量

本工作用平皿沉降法在北京市西单观测了大气细菌粒子的沉降量。结果表明,大气细菌粒子的年平均沉降量为72.9个/皿·5min;一天内大气细菌粒子沉降量出现7:00、19:00两个高峰时和13:00、夜间1:00两个低峰时。同时表明,大气细菌粒子的沉降量夏季高,冬季低;白天高,夜间低。     

Production of genetically modified cells expressing specific transgenes by retroviral vectors for gene therapy

Summary Techniques and protocols are described for the generation of genetically modified cells that can be used for gene therapy. Primary fibroblast cultures are established from skin biopsies, maintained in culture, frozen for long-term storage, and retrieved when necessary. Retroviral packaging cell lines are generated by transfection of DNA into retroviral packaging cells by calcium-phosphate precipitation method or by lipofection method. To generate cell lines expressing high titer virus, individual colonies of cells are cloned and the virus titer is determined. Virus collected from packaging cells expressing high titer virus is then used to infect primary fibroblasts. To obtain fibroblast cell lines expressing high amounts of transgenes, individual cells can be cloned to generate clonal cell lines. Although the methods described here are for fibroblasts, the same methods or modification of the methods can be used for other cell types.     

甲醇沉淀-高效液相色谱法同时测定奶茶中5种添加剂

目的建立甲醇沉淀-高效液相色谱同时测定奶茶中安赛蜜、苯甲酸、糖精钠、山梨酸和咖啡因的方法。方法样品加甲醇沉淀旋涡混合提取后,离心分离,取上清液,过0.22μm滤膜,高效液相色谱检测。色谱条件:使用Agilent Poroshell 120 EC-C₁₈(3 mm×150 mm,2.7μm)色谱柱,以甲醇和0.02 mol/L乙酸铵溶液为流动相,梯度洗脱,流速为1.0 ml/min,柱温为35℃,检测波长为240 nm。结果 5种添加剂在1.0μg/ml~50.0μg/ml线性良好,r>0.999 9,方法检出限为0.002 g/kg~0.005 g/kg,测定限为0.006 g/kg~0.015 g/kg。对饮料进行高、中、低3个浓度水平测定,回收率为93.36%~104.5%,相对标准偏差(RSD)为1.0%~3.4%。结论本方法样品预处理简单、分离效果好、准确度高,适用于奶茶中安赛蜜、苯甲酸、糖精钠、山梨酸和咖啡因的同时检测。     

黄芩苷标准品制备方法研究

采用醇提酸沉法提取黄芩苷粗品 ,再用分步精制的方法来制备黄芩苷标准品 ,所得标准品的熔点、含量与对照标准品一致。提示 :本法是制备黄芩苷标准品简便可行、收率高的方法     

Heparin-induced extracorporal low-density-lipoprotein precipitation (H. E. L. P.) to improve the recovery of hearing in patients with sudden idiopathic hearing loss

The pathogenesis of sudden hearing loss (SHL) is still not well understood. Possible causes include increased blood viscosity, microthrombosis or altered blood flow. Hypercholesterolemia, hyperfibrinogenemia and increased platelet aggregation are frequently observed in patients with SHL. The aim of this study was to investigate whether drastic lowering of plasma cholesterol and fibrinogen by selective extracorporal apheresis could have a beneficial effect on hearing recovery in these patients. Seven patients with SHL were treated with an extracorporal procedure removing fibrinogen and cholesterol from plasma. Six of the seven patients showed an immediate improvement in auditory thresholds following a single treatment of heparin-induced low-density lipoprotein precipitation. These findings indicate for the first time that acute and drastic removal of plasma fibrinogen and low-density lipoproteins may be an effective clinical method for the treatment of patients with SHL. Received: 19 February 1999 / Accepted: 6 May 1999