Association between common alleles of the low-density lipoprotein receptor gene region and interindividual variation in plasma lipid and apolipoprotein levels in a population-based sample from Rochester, Minnesota

This paper presents an analysis of the relationship between variation in the low-density lipoprotein receptor (LDLR) gene region and interindividual variation in plasma lipid and apolipoprotein levels in a sample representative of the adult population of Rochester, Minn. (217 females and 187 males aged 26 to 63). This relationship was analyzed by estimating the average excesses of alleles of the LDLR gene defined using RFLP markers both singly and simultaneously. We also used a cladistic approach to illustrate the consequences of incorporating evolutionary information into the analysis of genotype-phenotype relationships. Although results from both approaches supported the inference that common variation in the LDLR gene region associates with small effects on plasma lipid and apolipoprotein levels, only the cladistic approach provides direction for further work aimed at identifying the functional DNA sequence variations responsible for the observed associations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42270/1/439-99-1-108_60990108.pd

Impact of apolipoprotein E genotype variation on means, variances, and correlations of plasma lipid, lipoprotein, and apolipoprotein traits in octogenarians

The impact of apoliporotein (apo) E genotype variation on means, variances and correlations between plasma lipid traits was studied in male and female octogenarians. Females had significantly higher mean levels of all 10 of the measured plasma lipid traits than males. The subset of concomitants (i.e., age, height, weight, body mass index, glucose and uric acid) that made a statistically significant contribution to interindividual variability was different in males and females for every trait considered. Gender-specific associations between variation in apo E genotype and variation in pariticular measures of lipid metabolism, adjusted for concomitant variation, were observed: in females there were no statistically significant associations while in males the means of the three common apo E genotypes were significantly different for adjusted measures of total cholesterol, low density lipoprotein cholesterol and low density lipoprotin-apo B. The common apo E genotypes were heterogeneous with respect to intragenotypic variance for adjusted logtransformed triglyceride levels in females only. Finally, the three common apo E genotypes were heterogeneous with respect to the correlation between traits, adjusted for concomitant variation, and gender influenced the manner in which the genotypes differed for specific correlations. This study documents that variation in the apo E gene has a significant impact on means, variances and correlations of plasma lipid traits in octogenarians, but the effects are context-, that is, gender- and age-, dependent. © 1995 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38262/1/1320580405_ftp.pd

A measure of adaptation to problematic academic and interpersonal tasks of middle school

This study examined the development and validation of a measure of adaptation to problematic academic and interpersonal tasks that arise during the transition to middle school (Survey of Adaptational Tasks of Middle School -- SAT-MS). In terms of Bronfenbrenner's framework of "ecological transitions," a set of psychosocial tasks was reliably identified, and the perceived impact of these tasks was found to be related to self-concept and perceived school environment. Sex differences consistent with differential development expectations emerged. The results suggested that for girls, peer relationship tasks were most salient with regard to criterion measures, whereas for boys, peer relationshipm conflict with authority, and academic pressure tasks all related to criterion measures. The major findings were replicated for both a predominantly white, suburban sample and a predominantly urban, nonwhite sample. The results are discussed in terms of the needs of children during periods of adaptational challenge.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30113/1/0000488.pd