用线性动力学方法考察黄嘌呤对尿酸酶的抑制作用

目的:以米氏常数相差较大的两种尿酸酶为模型,考察用两个底物浓度下标定比活性确定酶动力学参数和筛选抑制剂的可靠性.方法:用293 nm吸收监测尿酸酶反应.通过两个底物浓度下标定比活性确定表观米氏常数(apparent michaelis-menten constant,Kmapp)和表观最大反应速度(apparent maximal reaction rate,Vmapp).据表观动力学参数随抑制剂浓度的变化确定抑制类型和抑制常数(inhibition constant,Ki).结果:只要所用尿酸浓度中较小者(the lower concentration of uric acid,SL)大于待测Km的0.8倍且较大者(the higher concentration of uric acid,SH)在SL的1.4倍以上,此线性动力学法能可靠测定Bacillusfastidiosus和Candida species尿酸酶的米氏常数,且与双倒数法结果一致.如SL大于Km的3.8倍而SH为SL的3倍,此线性动力学法所得Candida species尿酸酶Kmapp与抑制剂浓度成正比,Ki为(4.8±0.5)μmol/L,与双倒数法结果一致.Bacillus fastidiosus尿酸酶Km太高,底物浓度有限时不能用此方法筛选其抑制剂.结论:此线性动力学方法仅用高于Km的底物浓度也能可靠确定酶动力学参数,有利于用常规定量方法筛选对底物具有高亲合力特殊靶酶的抑制剂.     

多目标线性规划在医院人才预测中的应用

医院是一个复杂的社会系统,人才的科学预测与规划是医院管理的重要任务之一。本文应用运筹学的多目标线性规划方法进行人才预测,能根据实际情况,对医院内每年各级职称人才的拥有量、晋升及离退数等作出最优预测。     

The financial effects of emergency department-generated admissions under prospective payment systems

The purpose of this study was to assess the financial impact (revenues vs expenses) as measured by hospital charges and costs vs diagnosis-related group (DRG) revenues of prospective payment systems on emergency department-generated admissions for a large teaching hospital under two payment systems: Medicare and an all-payor system. All emergency department admissions were analyzed for the years 1983 (N = 4,273) and 1984 (N = 4,125) under both systems, using standard DRG methodology. Our findings were as follows: (1) With charges as a measure of expense under both payment schemes, all clinical departments had large groups of unprofitable patients: Medicare, $12,895,038; all-payor system, $15,553,893. (2) When costs were computed as the expense measure (using our hospital's cost-to-charge ratio), Medicare patients produced a deficit ($2,363,163); however, under an all-payor system there was a small net profit ($4,267,859). (3) The implementation of federalized DRG reimbursement rates increased our losses for this population from 1983 to 1984. (4) Reductions in outlier reimbursement (10%) and teaching costs (25%) caused our revenues to drop substantially, potentiating our losses. These findings suggest that hospitals with large emergency department admission populations, particularly Medicare patients, may be at a significant financial disadvantage under prospective payment systems.     

肥胖对雌性大鼠交感肾上腺系统的长期程序化作用

目的：研究肥胖对雌性大鼠交感肾上腺系统的长期程序化作用。方法：将雌性sD大鼠在出生当E1分成2组：①实验组,小窝喂养,每窝4只;②对照组,正常喂养,每窝12只。每周测体质量,出生后28d开始监测阴道口初开放时间和阴道细胞学涂片。出生后10周,用免疫组织化学方法测定肾上腺和卵巢交感神经兴奋性的改变;用原位杂交技术测定中枢蓝斑核的酪氨酸羟化酶（TH）mRNA的表达变化。结果z与对照组相比,实验组动物明显肥胖,持续终生;青春期启动明显提早[实验组（35．5土0．8）d,对照组（37．6±0．3）d];卵巢和肾上腺的TH免疫染色明显增强和蓝斑核的THmRNA表达明显增加,其差异均有统计学意义（均尸〈0．05）。结论：肥胖通过上调交感肾上腺兴奋性影响雌鼠的生殖功能。     

The financial cost to patients of visiting a GP in Ireland: a cross-sectional survey

Background  

Future general practice funding is much debated but public opinion has not previously been reported.     

队列半数生存期分析:非参数方法

在估价不同疗法对恶性疾病或其他慢性疾病疗效时,生存率比较有时会导致错误结论。因而由一个流行病学队列分析资料建立了非参数生存函数,绘制出生存折线及其95%的Alderson置信带。求出队列半数生存期(hlc)及其95%的置信限。以hlc作为评价统计学指标可以获得确切的结论,避免了生存率比较的缺点。在卫生学中,hlc拟用于估计寿命。在流行病学队列分析中,拟用于描述恶性疾病对寿命的影响,评价疗效和预防效果等。     

An application of linear programming discriminant analysis to classifying and predicting the symptomatic status of HIV/AIDS patients

This study presents an application of linear programming discriminant analysis (LPDA) to classify and to predict the symptomatic status of HIV/AIDS patients. We applied LPDA as well as several traditional discriminant analysis methods to the AIDS Cost and Services Utilization Survey data set in order to demonstrate the use of LPDA to classify the symptomatic status of HIV/AIDS patients. The potential benefit of LPDA in terms of the classification accuracy was also analyzed.