In vitro expression of the diphtheria toxin A-chain gene under the control of human chorionic gonadotropin gene promoters as a means of directing toxicity to ovarian cancer cell lines

OBJECTIVE: Our goal was to determine whether toxicity of the diphtheria toxin A-chain gene regulated by the human chorionic gonadotropin promoter can be directed to malignant ovarian cell lines. STUDY DESIGN: Plasmids containing diphtheria toxin A-chain gene linked to the regulatory elements of the metalloergothioneine and human chorionic gonadotropin promoters were transfected into the cell lines. Expression of diphtheria toxin A-chain gene was determined by the inhibition of a cotransfected luciferase reporter gene. RESULTS: Cytotoxicity of the diphtheria toxin A-chain gene is shown in a dose-responsive manner. Transfection of a plasmid expressing the diphtheria toxin A-chain gene controlled by a constitutive promoter readily inhibits protein synthesis. Specific inhibition of luciferase protein synthesis occurs in ovarian cancer cells transfected with the diphtheria toxin A-chain gene under the control of the human chorionic gonadotropin promoters when compared with normal ovarian epithelial cells or fibroblasts. CONCLUSIONS: These data demonstrate the preferential expression of the diphtheria toxin A-chain gene, regulated by the human chorionic gonadotropin promoter, to ovarian cancer cell lines. This provides an avenue for targeting such cells for suicide, toxin, or cytokine genes.     

Testing Mediational Models With Longitudinal Data: Questions and Tips in the Use of Structural Equation Modeling.

R. M. Baron and D. A. Kenny (1986; see record 1987-13085-001) provided clarion conceptual and methodological guidelines for testing mediational models with cross-sectional data. Graduating from cross-sectional to longitudinal designs enables researchers to make more rigorous inferences about the causal relations implied by such models. In this transition, misconceptions and erroneous assumptions are the norm. First, we describe some of the questions that arise (and misconceptions that sometimes emerge) in longitudinal tests of mediational models. We also provide a collection of tips for structural equation modeling (SEM) of mediational processes. Finally, we suggest a series of 5 steps when using SEM to test mediational processes in longitudinal designs: testing the measurement model, testing for added components, testing for omitted paths, testing the stationarity assumption, and estimating the mediational effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Institutional research productivity in industrial/organizational psychology.

Updated the report of W. M. Cox and V. Catt (see record 1978-21651-001) by determining the 40 top contributing institutions to the Journal of Applied Psychology, 1976–1982, and assessed the generalizability of productivity rankings based solely on contributions to this journal. A number of industrial and organizational psychologists were asked to indicate all the journals in which psychologists in the field were likely to publish. Five journals suggested by these nominators were used for comparison in the review. A list of the 40 most productive graduate programs based on these 5 journals is included. Results show the inadequacy of Cox and Catt's decision to base productivity ratings solely on contributions to 1 journal. Using 5 journals, 4 programs were catapulted into the top 10 rankings, while 7 programs dropped from top rankings in the Cox study (1970–1975) to below the 65th rank in the present study. Using only the Journal of Applied Psychology contributions, 2 of these programs ranked in the top 10, 1976–1982. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reliability artifacts in comparable worth procedures.

Comparable worth principles suggest that regression line differences between male- and female-dominated jobs be examined where pay is regressed on job evaluation point values. It is demonstrated that unreliable job evaluation measures could artifactually produce regression line differences between male- and female-dominated jobs, even when no such bias exists. A. S. Goldberger's (1984) reverse regression and other procedures are examined as alternative methods of determining bias, and it is shown that linear structural relations procedures provide accurate and nonbiased estimates of wage discrimination in comparable worth analyses. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement and statistics: An examination of construct validity.

Uses principles of latent trait theory to derive conditions under which mean differences on an observed variable are indicative of mean differences on an underlying construct, focusing on the logistic curve as a model for describing the relation between the observed variable and construct. In this situation, and with normally distributed scores on the construct, a t test comparing groups on the observed variable produces correct inferences at the construct level only if group variances on the construct are homogeneous or the difficulty level of the test equals the mean ability level of the examinees. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Construct validity of measures of college teaching effectiveness.

Compared evaluation form, student, colleague, trained observer, former student, and self-rating teacher assessments of 43 university instructors. Data show that student and former student ratings displayed substantially greater validity coefficients of teaching effectiveness than self-report, colleague, and trained observer ratings. Advantages of student rating techniques (i.e., greater exposure to instructor's teaching), various teaching assessment methods, and problems in the literature due to limitations of research approaches typically used are discussed. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction to the special section on Campbell’s and Rubin’s conceptualizations of causality.

Causality plays a fundamental role in scientific explanation. This introduction describes 2 target articles and 3 commentaries on 2 influential perspectives on causal inference, one developed by Donald Campbell and the other developed by Donald Rubin. One goal of this special section is to introduce Rubin’s causal model to psychologists who may be largely unfamiliar with it. Another goal is to compare Rubin’s conceptualization with Campbell’s perspective, to enrich readers’ understanding of both views. All of the authors of this special section perceive many similarities between the 2 approaches. Even so, by comparing and contrasting the 2 perspectives, the authors also believe that it is possible to strengthen both approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multivariate statistics for family psychology research.

The application of selected multivariate statistics is illustrated for use in family psychology research. The use of multivariate analysis of variance (MANOVA) and discriminant analysis in factorial designs and profile analysis is discussed. Profile analysis provides a method for dealing with unit of analysis issues in family psychology research. Applications of confirmatory factor analysis are also discussed as useful methods for researchers examining multiple components of families and handling multiple perspectives of various family members. Limitations and applications of these methods in family psychology research are reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlation between student satisfaction and grades: A case of mistaken causation?

The correlation between grades of instruction and student satisfaction has been interpreted as providing support for a grading leniency bias model; that is, easy graders receive better evaluations than hard graders because they are easy graders. Two alternative models that explain the correlation of grades with satisfaction are delineated. A student characteristics model (student motivation) is contrasted with the grading leniency bias model in 2 studies. Study 1 considered between-class relationships among grades, satisfaction, performance, and student motivation for the IDEA (Instructional Development and Effectiveness Assessment System) data from several thousand college and university classes across the US. Study 2 considered within-class relationships among grades, satisfaction, performance, and motivation for 19 large university classes. Both studies demonstrate that the relationship between grades and student satisfaction might be viewed as a welcome result of important causal relationships among other variables rather than simply as evidence of contamination due to grading leniency. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)