肝癌患者血清P-选择素测定及临床意义

目的：研究肝癌患血清P-selection(P-sel)在肝癌复发和转移中的作用。方法：采用ELISA法分别测定原发性肝癌患和对照组血清P-选择素的含量，同时测定AFP含量。结果：肝癌患P-sel含量显高于正常人，且与AFP含量呈线性正相关，术后2周浓度降低；P-sel含量以Ⅰ、Ⅲ和Ⅳ期肝癌患显高于Ⅰ期患；且大肝癌患显高于小肝癌患，有癌栓组、有肝内转移组明显高于无癌栓组和无转移组。结论：P-选择素测定在原发性肝癌的诊断和检测术后复发方面有重要价值，联合检测AFP和sP-sel可提高诊断敏感性。     

A hole in the T cell repertoire specific for a pigeon cytochrome c related peptide associated with amino acid substitutions on I-Ab molecules.

When C57BL/10(B10) mice were immunized with a pigeon cytochrome c related peptide, 50V (AEGFSYTVANKNKGIT), two helper T cell populations with different specificity were activated. A major T cell population reacted with a 50V analog, 50V54A (AEGFSYTVANKAKGIT), more potently than with the immunogen, 50V, in a heteroclitic fashion, whereas the other minor T cell population responded only to 50V. By contrast, when bm12 mice were immunized with 50V, the minor T cell population responding only to 50V could hardly be demonstrated. The apparent deletion of the minor T cell population in bm12 mice seems to be attributable to negative selection under the influence of I-Abm12 molecules, since the minor T cell population was undetectable in both I-Ab and I-Abm12 restricted T cells from (B10 x bm12)F1 mice. Thus, three mutant points on the I-A molecule in bm12 mice appear to be involved in the seemingly negative selection of the certain T cell repertoire. The present finding demonstrates that a T cell repertoire generated under the influence of a MHC product (Ab) on one parental strain is eliminated by a different MHC product (Abm12) on the other parental strain of F1 cross. The mechanism underlying the apparent negative selection is discussed.     

Self-selection of enrollers at the creation of a managed care organization

Factors affecting choice between a managed care organization(MCO) and a fee-for-service insurance plan were examined whenthe University of Geneva health insurance plan was transformedinto an MCO, in October 1992. A case-control study using a mailedquestionnaire (response rate 84%) was conducted to compare formermembers who joined the MCO (joiners, n=421) to former memberswho opted out in order to keep fee-for-service coverage (non-joiners,n=222). Non-joiners were more likely to be women (odds ratio(OR) from multivariate model was 1.15, p=0.50), to be born inSwitzerland (OR=2.04, p<0.01), to have an annual income >75,000Swiss francs (OR=2.00, p<0.01), to have a personal physician(OR=1.96, p<0.01) and to have consulted a specialist (OR=1.69,p=0.02) or used unconventional medicine (OR=4.59, p<0.01)in the past year. During the previous year, non-joiners hadmore health care visits than joiners (14.6 versus 9.1, p=0.01).Non-joiners reported better mental health and fewer complainedof persistent fatigue (OR=2.18, p=0.03). The choice of healthplan was strongly influenced by socio-demographic characteristics,past patterns of health services utilization and health status.The self-selection process was paradoxical: MCO joiners hadused fewer health care visits than non-joiners, but their self-reportedhealth status was worse. The differences we have observed betweenself-selected populations have important implications for thefinancial performance of competing health care delivery systems.     

水稻品种抗褐稻虱的遗传机制及表型稳定性的研究

本文研究了15个水稻品种的抗性遗传，品种国眉占的抗性受一对隐性基因控制，BG367－4受两对隐性基因控制；三桂占1、Suweon294、KAU1727、IR13539－100－2－2－2－3、IR749－5－2－1－1以及IR13240－108－2－2－3均受一对显性基因控制；IR25586－108－1－2－2－2受两对显性基因控制；三黄占2、三叶占1、铁六选；新惠占1、GENG77－4以及IR13427－40－2－3－3都受一对显性基因和一对隐性基因因控制，同时对12个具有不同抗性水平的水稻品种苗期的抗菌表现进行了遗传型稳定性分析。结果表明，不同品种的抗性稳定性有明显差异，TN1是极稳定的高感品种TG367－4、25586-108－1－2－2－2以及Mudgo是非常稳定的高抗;一叶占1、三桂占1和铁六这三个抗级品种的抗虫也较稳定;；而抗级品种国眉占、三黄占2、Suweon294和抗品种包选2、辐包矫21的抗虫性不稳定。     

Hospital versus population controls in a retrospective study on diet and stomach cancer

The aim of the present study is to evaluate drawbacks and advantagesof the choice of hospital versus population controls in a casecontrol study on diet and cancer through the analysis of a retrospectivestudy on diet and gastric cancer (GC) conducted in Forli, Italy,involving 232 cases, 430 population controls and 252 hospitalizedcontrols. The present paper reports the comparison of resultson diet and GC risk obtained using the 2 types of controls.Population controls tended, in general, to eat all kinds offoods slightly more frequently (bread, pasta, cold cuts, freshfish, seasoned cheeses, legumes, garlic, onions and preservedfruits), with the exception of cooked vegetables, which werereported less frequently by population than by hospital controls.ORs for specific foods adjusted for confounders and other foodswere consistent in the separate models including populationand hospital controls respectively for all food groups, withthe exception of cooked vegetables which represented a protectivefactor only when hospital controls were considered (high consumers,population controls: adjusted, OR=0.9, trend p value 0.54; highconsumers, hospital controls, adjusted OR=0.5, trend p value<0.01). Hospital controls were slightly less often currentsmokers (22.6 versus 30.0%) and more often regular wine drinkers(57.5 versus 47.8%) compared with population controls, but noneof these variables was associated with GC risk. The main resultsin this study were consistent using both types of controls,nevertheless the distribution of some dietary variables notrelated to the disease under study differed between the 2 controlgroups, suggesting some caution in the use of hospital controlswhen studying diseases other than GC.     

Adiabatic refocusing pulses for volume selection in magnetic resonance spectroscopic imaging.

Because of their excellent slice profiles and high immunity to RF inhomogeneity, adiabatic full passage (AFP) pulses are ideal for use in spatial localization. The nonlinear, position-dependent phase of a single AFP pulse generated during refocusing of transverse magnetization traditionally is eliminated by using identical pairs of AFP pulses, at the expense of increased RF power deposition and increased echo time (TE). Here it is shown that one can achieve significant phase refocusing by executing single AFP pulses along non-equivalent spatial axes. When used for volume selection in MR spectroscopic imaging (MRSI) the remaining nonlinear phase becomes inconsequential when the phase across a spectroscopic volume is small. Selection of rectangular and octagonal volumes is demonstrated with half the number of AFP pulses used in the traditional approach. It is shown that octagonal volume selection in the human brain provides excellent suppression of extracranial lipids, and thus allows multislice (1)H MRSI at 4 Tesla to be performed within the guidelines for RF power deposition.     

不同性别飞行学员人格特征的比较

目的 :探讨男女飞行学员人格特征的差别 ,为选拔战斗机女飞行员提供心理选拔方法的参照 .方法 :女学员组为某飞行学院 2 2名女飞行学员 ,男学员组为同一飞行学院 4 3名男飞行学员 .采用卡特尔 16种个性因素测验 (16PF) ,应用DXC多项心理测评仪进行集体测试 .结果 :在 16PF的 2 4个分析项目中 ,情绪的稳定性 (C)、兴奋性 (F)、敢为性 (H)、怀疑性 (L)、紧张性 (Q4)、适应与焦虑、内向与外向等 7个因子分男学员和女学员有显著差异 (P <0 .0 5或P <0 .0 1) ,其中在稳定性、兴奋性、敢为性和外向性等 4个因素上 ,女学员的分数显著高于男学员 (P <0 .0 5或P <0 .0 1) ;而在怀疑性、紧张性、焦虑性等 3个因子分上则是男学员显著高于女学员(P <0 .0 5或P <0 .0 1) .结论 :女飞行学员的个性特点是情绪稳定 ,轻松兴奋 ,冒险敢为 ,适应环境 ,趋于外向 ,紧张困扰和焦虑较少 .本调查结果表明 ,女飞行学员的人格特征基本符合战斗机飞行员人格结构的要求     

Selection and the effect of prenatal smoking

There is a debate about the extent to which the effect of prenatal smoking on infant health outcomes is causal. Poor outcomes could be attributable to mother characteristics, which are correlated with smoking. I examine the importance of selection on the effect of prenatal smoking by using three British cohorts where the mothers' knowledge about the harms of prenatal smoking varied substantially. I find that the effect of smoking on the probability of a low birth weight birth conditional on gestation is slightly more than twice as large in 2000 compared with 1958, implying that selection could explain as much as 50% of the current association between smoking and birth outcomes. Copyright © 2009 John Wiley & Sons, Ltd.     

Can marital selection explain the differences in health between married and divorced people? From a longitudinal study of a British birth cohort

In view of the rising divorce rates, the impact of divorce on health has an increasing importance in public health. The differentials in health between the married and the divorced may be explained by ‘marital selection’ and ‘marital protection’. Using longitudinal data from a study of the 1958 British birth cohort, factors that select people into divorce were identified from the areas of socio-economic status, health, and attractiveness, which included physical attractiveness, health-related behaviour and temperament. Evidence for both positive and adverse selection is found. The different sets of selection factors for females and males appear to be in line with gender role expectations. The health differentials between married and divorced men were weak and can be explained away by the selection factors. Having controlled for the selection effects, there were still significant associations between divorce and physical and psychological health in women. Though these unexplained differentials cannot be definitely interpreted as the consequences of marital dissolution, this interpretation remains plausible.     

Selection for increased pheromone response in the male pink bollworm,Pectinophora gossypiella (lepidoptera: Gelechiidae)

The genetic basis of the duration and incidence of male wing fanning to pheromone in the pink bollworm moth,Pectinophora gossypiella (Saunders), was examined by artificial selection. Using a still-air bioassay, males from a laboratory colony were selected for increased duration of wing fanning when exposed to a 6535 blend of (Z,E)- and (Z,Z)-7,11-hexadecadienyl acetates. The mean (±SE) duration of wing fanning in the selected line increased from 5.4±1.4 to 17.4±2.7 s after six generations. The increase in wing fanning duration was the result of an increase in response duration among responders and not the percentage of males that responded. Realized heritability of wing-fanning duration was 0.16±0.02. The amount and ratio of pheromone produced by females in the male-selected line did not change.This research was supported in part by NSF Grant PCM-8309398 and a University of Massachusetts Biomedical Research Grant.