Apolipoprotein B mRNA editing and apolipoprotein gene expression in the liver of hyperinsulinemic fatty zucker rats: Relationship to very low density lipoprotein composition

We previously demonstrated increased apolipoprotein B (apoB) mRNA editing, elevated levels of mRNA for the catalytic component of the apoB mRNA editing complex, apobec-1, and increased secretion of the product of the edited mRNA, apoB48, in very low density lipoproteins (VLDL) in primary cultures of Sprague-Dawley rat hepatocytes following insulin treatment. In order to determine the effect of in vivo hyperinsulinemia on these processes, we determined apoB mRNA editing, apobec-1 expression, hepatic expression of mRNA for apoB and other VLDL apoproteins, and the quantity and composition of plasma VLDL in the hyperinsulinemic fatty Zucker rat. Total apoB mRNA content of the livers of the fatty rats and lean littermates did not differ, however, edited apoB message coding for hepatic apo B48, and abundance of mRNA for the catalytic subunit of the apoB mRNA editing complex, apobec-1, was increased by 1.7-and 3.3-fold, respectively, in fatty rats. ApoCIII mRNA abundance was increased in livers of fatty rats as well, but the abundance of hepatic apoE mRNA in the fatty animal was not different from that of the lean rat. Hepatic apoAI mRNA abundance was also increased in the fatty rats. Associated with increased apoB mRNA editing, was the 1.7-fold increase in the fraction of apoB in plasma as apoB48 in fatty rats. VLDL-triglyceride and-apoB in plasma were 15-and 3-fold higher, respectively, in fatty Zucker rats compared to lean littermates, indicating both enrichment of VLDL with triglycerides and increased accumulation of VLDL particles. Increased hepatic expression of mRNA for apoCIII and apoAI was associated with increased content of apoC (and relative depletion of apoE) in VLDL of fatty rats, and plasma apoAI was increased in fatty Zucker rats, primarily in the HDL fraction. The current study provides further evidence that chronic exposure to high levels of insulin influences both the quantity of and lipid/apoprotein composition of VLDL in plasma. The increased apoC and decreased apoE (as well as increased triglyceride) content of VLDL in the fatty Zucker rat observed in the current study may affect VLDL clearance and therefore may be a factor in the observed accumulation of VLDL in the plasma of the fatty hyperinsulinemic Zucker rats.     

Sensory evaluation of bitterness and astringency of 3R(−)-epicatechin and 3S(+)-catechin

Bitterness and astringency of the monomeric flavan-3-o!s ( + )-catechin and (?)-epicatechin were rated using time-intensity (T-I) methodology. Three concentration levels (0.5. 0.9 and 1.2 g liter^?1) oi each compound were assessed, and the parameters time to maximum intensity (TMAX), intensity at the maximum (IMAX) and total duration (TTOT) were extracted from the T-I curves. No differences in TMAX for either bitterness or astringency were found between these chiral isomers or as a function of concentration within a compound. Epicatechin had a significantly higher bitter IMAX than catechin at all three concentration levels, and had a significantly longer TTOT at the two higher concentrations. Epicatechin was more astringent than catechin. but this was only significant at one concentration. Astringency TTOT was longer for epicatechin, although this was nonsignificant at the lowest concentration. The three concentrations of catechin were significantly different for both bitterness and astringency IMAX and TTOT. Epicatechin showed evidence for the astringency response plateauing above the 0.9 g litre^?1 level. n-Propylthiouracil status had no effect on perception of either bitterness or astringency.     

A Redefinition of Odor Mixture Quality.

Odor mixtures are perceived as different from (configural) or the same as (elemental) their components. Recent studies (L. M. Kay, C. A. Lowry, & H. A. Jacobs, 2003; C. Wiltrout, S. Dogra, & C. Linster, 2003) propose that component structural or perceptual similarities predict configural properties of binary mixtures. The authors evaluated this in rats using 4 binary mixtures with varying structural similarity (eucalyptol-benzaldehyde, eugenol-benzaldehyde, octanol-octanal, and [+/-]-limonene). The range of tested ratios for each mixture was determined by the components' vapor pressures. Three results are presented: (a) No mixture maintains purely elemental or configural properties for all concentration ratios, (b) structural similarity or dissimilarity does not predict configural or elemental perception, and (c) overshadowing is significant in responses to all odor sets. The authors offer more precise definitions of elemental and configural properties and overshadowing as they relate to odor mixture perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Got a minute? Attentional limits revisited.

Responds to comments by R. C. Tees (see record 1991-03035-001), J. G. Adair (see record 1991-03013-001), J. E. Grusec (see record 1991-03021-001), K. Danziger (see record 1991-03016-001), L. P. Mos (see record 1991-03027-001), H. J. Stam (see record 1991-03033-001), and V. Vikis-Freilbergs (see record 1991-03039-001) on W. Thorngate's (see record 1991-03036-001) contention that the overproduction of psychological literature will lead to fragmentation of the discipline. As the works of psychologists proliterate, their scientific truth may capture less attention than their practical importance or personal interest. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction and perception of social motives.

In 2 experiments 70 male and female and 89 female undergraduates were required to observe and predict the behavior of a hypothetical "chooser" who made choices for him- or herself and for a hypothetical other in a series of decomposed games. The preference for outcomes, or social motivational orientation, of the chooser was preprogramed and varied across conditions. Ss were more readily able to detect the outcome preferences of choosers who made choices according to individualistic or competitive choice rules than of choosers who behaved in a prosocial or negatively self-interested manner. Furthermore, the prediction data from Exp II reveal that Ss tended to perceive choosers' own gain as an important component of most of the choosers' secondary motivation. Evidence from Ss' ratings of the choosers' personality attributes and estimates of the relative weights the choosers attached to their own and the other's gain (Exp II) indicated that Ss formed distinctive impressions of the choosers despite differences in predictive accuracy across conditions. Exp III with 64 undergraduates was performed to investigate the relationship between predictive accuracy and the mathematical complexity of the choosers' various choice rules; no evidence was found that mathematical complexity influenced Ss' performance on the prediction task. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The economy of attention and the development of psychology.

Suggests that the production and consumption of information, including the information called psychology, require investments of attention. Yet attention is a limited resource, so, as more information is produced, more products must compete for the limited attention of consumers. Ideally, the competition should lead to better information and should lead consumers to pay attention only to the best. However, as more information is produced, there is more digression from these progressive ideals due to the nature of attention and the principles of attentional economics governing information exchange. If these trends continue, they may cause the disintegration of psychology as a discipline. Means of reducing information production through changes in academic reward systems are outlined. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)