PA317产生高滴度带有人TNF-α基因逆转录病毒的研究

逆转录病毒介导的基因转移技术要过渡到临床应用，主要解决如何使病毒载体具有高滴度而不具有复制活性．本文旨在探索建立一种合适的方法，能产生高滴度而且是安全的逆转录病毒载体。采用带有人肿瘤坏死因子基因的LXSN载体转染PA317包装细胞，建立产病毒的包装细胞株，结果表明：病毒载体滴度受包装培养液体积和胎牛血清浓度影响：包装细胞在32℃产生的病毒滴度比37℃高，而且比较稳定。产病毒包装细胞和被感染的靶细胞经PCR分析显示．被转染和被转导的细胞都有病毒基因的整合．而且包装细胞不会产生具有复制活性的逆转录病毒，因此能进一步用于临床研究．     

A case-control study on risk of changing food consumption for colorectal cancer

Objectives. To investigate the relative risk factor of food items for colorectal cancer in four time periods through a case-control study in a Chinese rural area.

Methods. Colorectal cancer patients diagnosed at a county cancer center, Hebei Province, China, and non-cancer outpatients with similar age, sex, and place of residence were selected for cases and controls, respectively. There were 102 (93.6%) colorectal cancer patients and 99 (90.8%) outpatients being the cases and controls, respectively in the present investigation, who agreed to be interviewed about their food intake, during a 20-year period, through a food frequency questionnaire. The risks of intake of different food items and lifestyle for colorectal cancer were compared between cases and controls.

Results. During the 20-year period, diets of both cases and controls changed with increase in intake of animal foods and fruits, and alcohol consumption tended to increase. In the food items, milk intake showed a protective effect in both males and females, and the odds ratios were 0.38 (95% CI 0.16-0.90) and 0.28 (95% CI 0.10-0.81) for males and females, respectively. A reduced risk of fruit intake could be seen in males, while a reduced risk of vegetables could be observed in females. Meat intake and saturated fats were the prominent risk factors for colorectal cancer in males and females, respectively. A comparison of life habits, showed that tea drinking had a consistent protective effect in females, and the odds ratios were 0.21 (0.08-0.58), 0.23 (0.08-0.67), 0.25 (0.10-0.64), and 0.11 (0.04-0.30) for periods of 20-, 10-, 5-years ago, and current time, respectively.

Conclusions. These findings indicate that change in food consumption is strongly associated with a change in risk of colorectal cancer, and dietary meat has increased the risk of colorectal cancer. Increase in the consumption of milk and fruits may be a significant measure for colorectal cancer prevention in low-incidence areas.     

干化学试纸法与全自动生化分析仪酶法生化项目检测的比较分析

目的比较干化学试纸法与全自动生化分析仪酶法检测各项生化项目的相关性.方法对干化学试纸法和全自动生化分析仪酶法检测血糖、肌酐、尿素、a-淀粉酶的结果进行比较分析.结果干化学试纸法与全自动生化分析仪酶法各项血生化项目检测结果有高度正相关性(r＞0.975),无显著性差别(P＞0.05),且批内变异系数小于5%,精密度高.结论干化学试纸法具有准确、快速、重复性好、可用全血进行检测、无需定标及试纸易保存等优点,适用于临床实验诊断中心(检验科)急诊化验室急诊生化项目的检测.     

同源异形盒Gax基因重组腺病毒载体的构建及其鉴定

目的:构建同源异形盒Gax基因的复制缺陷型腺病毒载体,并对其是否重组成功进行鉴定。方法:采用两步CaC l2转化法的DNA细菌内同源重组技术,PCR扩增小鼠Gax基因,将Gax基因克隆于腺病毒穿梭质粒pAdTrack-CMV,转染含有5型腺病毒骨架质粒pAdeasy-1(33.5 kb)的B J5183细菌,经细菌内同源重组产生携带Gax基因的重组腺病毒载体pAd-Gax,经限制性内切酶BstⅨ和PacⅠ鉴定正确后,用脂质体法转染293细胞,包装产生携带Gax基因的重组腺病毒Ad-Gax。利用GFP的表达鉴定Ad-Gax。结果:构建了表达Gax基因的复制缺陷型腺病毒,病毒滴度达4×1010pfu/L。结论:成功地构建了表达Gax基因的复制缺陷型腺病毒载体,为进一步研究Gax基因在心血管病中的作用提供了实验基础。     

Comparison of health-related quality of life questionnaires in ambulatory oncology

The purpose of this study is to compare three commonly used health-related quality of life (HR-QOL) questionnaires for their ease of use, accuracy, and patient preference; identify factors related to patient preference; identify differences in patient completion rates; and to identify factors associated with patient completion of these questionnaires. Three psychometrically sound measures, the Symptom Distress Scale (SDS), Medical Outcome Study Short Form-36 (SF-36), and Functional Assessment of Cancer Therapy (FACT), were tested. Seventy-nine patients completed questionnaires in the ambulatory oncology setting. No significant differences in patient ratings were found in ease of use and accuracy among the questionnaires. All of the questionnaires were rated as easy to use and accurate. Patient ratings on preference were marginally significant (p=0.07). Forty-six percent of participants indicated that they preferred the SDS, whereas 27 and 39 preferred the SF-36 and the FACT. No significant differences in patient completion rates were found among the questionnaires. One hundred percent completion rates ranged from 88.6 for the SDS to 78.5 for the SF-36, and 80 completion rates ranged from 98.7 for the SDS to 94.9 for the SF-36. Administration of standardized HR-QOL questionnaires is feasible in the clinical setting.This research was supported by an American Cancer Society Institutional Research Grant (IRG 58-012-42) through Yale Comprehensive Cancer Center and a grant from Bayer Pharmaceutical Company.     

Item Analysis to Improve Reliability for an Internal Medicine Undergraduate OSCE

Utilization of objective structured clinical examinations (OSCEs) for final assessment of medical students in Internal Medicine requires a representative sample of OSCE stations. The reliability and generalizability of OSCE scores provides validity evidence for OSCE scores and supports its contribution to the final clinical grade of medical students. The objective of this study was to perform item analysis using OSCE stations as the unit of analysis and evaluate the extent to which OSCE score reliability can be improved using item analysis data. OSCE scores from eight cohorts of fourth-year medical students (n = 435) in a 6-year undergraduate program were analyzed. Generalizability (G) coefficients of OSCE scores were computed for each cohort. Item analysis was performed by considering each OSCE station as an item and computing the corrected item-total correlation. OSCE stations which negatively impacted the reliability were deleted and the G-coefficient was recalculated. The G-coefficients of OSCE scores from the eight cohorts ranged from 0.48 to 0.80 (median 0.62). The median number of OSCE stations that negatively impacted the G-coefficient was 3.5 (out of a median of 25 total stations). When the ‘‘problem stations’’ were deleted, the median G-coefficient across eight cohorts increased to 0.62--0.72. In conclusion, item analysis of OSCE stations is useful and should be performed to improve the reliability of total OSCE scores. Problem stations can then be identified and improved.     

Psychometric Properties of the Cervical Smear Belief Inventory for Chinese Women

This study examines the reliability and validity of the scores of Cervical Smear Belief Inventory (CSBI) among Chinese women in Taiwan. Women who were nonadherent to cervical screening guidelines were recruited (N = 424). Reliabilities showed good internal consistency for the perceived Pros, Cons, and Susceptibility scales (α ranged from .78 to .87). Factor analysis showed good construct validity of the scores of CSBI that revealed concordant patterns with existing social and behavioral theories, except that the Norms scale was loaded with the Pros scale. Moreover, two items in the Cons scale appeared to be “cultural belief toward virginity.” Item-discrimination analysis showed that all items in the CSBI successfully discriminated women with favorable cervical smear beliefs from those with unfavorable beliefs (p < .001). In summary, many psychometric properties of the CSBI showed that the scores of the inventory were reliable and valid to assess belief toward cervical smear among Chinese women.     

Normal variation and abnormality: an empirical study of the liability distributions underlying depression and delinquency

BACKGROUND: Scale scores in studies of emotional and behavioural problems often possess highly skewed distributions. The long upper tails of these distributions place a small proportion of the population at some distance from the main body of the distribution. This invites an interpretation of their forming an abnormal group, one that may be qualitatively distinct. METHODS: Item-response models were fitted to data on parent and self-rated depression and delinquency from four large samples of children or adolescents. RESULTS: We found that underlying liability distributions show very little or no evidence of non-normality. CONCLUSIONS: The results suggest that (i) the skewed nature of the scale scores may be largely measurement artefacts, (ii) the distributions provide no evidence of a qualitatively distinct process generating abnormality as compared to normal variation and (iii) for characterising the whole distribution, including normality and abnormality, the selection of items in typical current assessments of emotional and behavioural problems is not optimal.     

Considerations for Measuring Functioning of the Elderly: IRM Dimensionality and Scaling Analysis

Modern measurement methods were applied in this study to examine the properties of a measure of functioning of the elderly. Measures of functioning form an essential element in health services and outcomes research. Several implications for scale development and improved score precision are presented in this case study. This study examined the structure of responses to the Older Americans Resources and Services (OARS) Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) scales using item response model (IRM) analysis methods. The analysis illustrates the extension of IRM dimensionality and item analysis to health scales in general. Attention is given to the underlying theory and appropriate interpretation of these methods for health measurement.Data were taken from 1364 elderly Canadians participating in the caregiver component of the Canadian Study of Health and Aging (CSHA). The fit of a two-parameter logistic IRM was compared with a one-parameter (Rasch) model for these data. The dimensionality of responses to the scale was evaluated with an approximate ² test of residuals after fitting an IRM based on non-linear factor analysis. Results confirm that ADL and IADL item sets differ in the degree of disability they measure and are well represented as separate dimensions using a two-parameter IRM. Implications are drawn concerning the adequacy of the OARS disability measure for health surveys, while more general conclusions cover the precision of IRM based optimal scoring for functional disability measures.