Reexamination of a plea for multivariate analyses.

Re-examines 2 issues raised in an article by M. R. Leary and E. M. Altmaier (see record 1981-02539-001) proposing MANOVA as a solution to the problem of inflated Type I error. Guidelines are discussed for choosing an overall MANOVA test statistic and post hoc tests that determine the dependent variable or variables responsible for any significant effects. It is concluded that guidelines based on recent comparisons of the various test statistics be used by researchers rather than advice found in basic textbooks. A discussion of the power of MANOVA concludes that although MANOVA may under some conditions reduce the chances of detecting significance, it is powerful for detecting legitimate experimental effects that are spread across more than one dependent variable. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cranberries and Wild Blueberries Treated with Gastrointestinal Enzymes Positively Modify Glutathione Mechanisms in Caco‐2 Cells In Vitro

Beneficial health effects of cranberries (CBs) and wild blueberries (BBs), such as reduced levels of oxidative stress, have been demonstrated in feeding studies. These Vaccinium berries contain high levels of flavonoids; however, the bioavailability of flavonoids is generally low. We investigated the in vitro effects of these berries on intestinal cells, focusing on mitigating oxidative stress and associated reactive oxygen species (ROS). First, we simulated the passage of CB and BB through the gastrointestinal (GI) tract by treating berry homogenates to a battery of digestive enzymes. Then, Caco‐2 cells, a model of small intestine epithelial uptake, were exposed to these homogenates for 60 min. Using a cell‐free assay, we found that the antioxidant activity in CB homogenates was not affected by these enzymes, but that BB homogenates treated with gut enzymes had 43% lower free‐radical quenching activity (P < 0.05). However, both of the enzyme‐treated homogenates were still able to counteract the ROS‐generating ability of H₂O₂ added exogenously to Caco‐2 cells. Berry homogenates also increased mitochondrial metabolic rates at 60 min posttreatment, as measured by MTT assays. Enzyme‐treated CB (but not BB) homogenates increased the levels of reduced glutathione (GSH) relative to oxidized glutathione (GSSG), a critical indicator of the cellular redox state (P < 0.05). Our data suggest that CBs do not lose their antioxidant ability when passing through the GI tract, and specifically, digested CB may serve to enhance cytoprotective effects in intestinal cells by reducing potential damage caused by free radicals and ROS derived from other food sources.     

Is hemin responsible for the susceptibility of Plasmodia to oxidant stress?

Based on the unusually high and stage-dependent susceptibility of Plasmodia to oxidant stress it has been proposed that during parasite development, increasing levels of redox-active forms of iron are gradually released. The purpose of this study was to examine this proposal by using an assay monitoring the levels of available forms of iron for redox reactions. Ascorbate-driven and iron-mediated degradation of adventitious DNA served as the basis for this functional assay. Incubation of DNA with lysate from infected RBC caused massive degradation, which was dose, time- and parasite-stage dependent. In contrast, lysate from non-infected RBC did not induce DNA degradation. Likewise, lysate only from infected RBC enhanced the aerobic oxidation of ascorbate. These effects on both reaction, DNA degradation and ascorbate oxidation, could be reconstructed with hemin, instead of lysate. Also, chelators exerted similar effects on both reactions. The results suggest that increased levels of redox-active forms of iron are liberated during parasite development. We propose that hemin or hemin-like structures are the appropriate candidates which could catalyze oxidative stress and deregulate the delicate redox balance of the host-parasite system.     

MALDI‐TOF MS characterization of proanthocyanidins from cranberry fruit (Vaccinium macrocarpon) that inhibit tumor cell growth and matrix metalloproteinase expression in vitro

Proanthocyanidin‐rich extracts were prepared by fractionation of the fruit of the North American cranberry (Vaccinium macrocarpon). In vitro growth inhibition assays in eight tumor cell lines showed that selected fractions inhibited the growth of H460 lung tumors, HT‐29 colon and K562 leukemia cells at GI₅₀ values ranging from 20 to 80 µg ml^?1. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) of one of these fractions found it to be composed of polyflavan‐3‐ols, which are primarily tetramers through heptamers of epicatechin containing one or two A‐type linkages. Whole cranberry extract and the proanthocyanidin fractions were screened for effect on the expression of matrix metalloproteinases in DU 145 prostate carcinoma cells. The expression of MMP‐2 and MMP‐9 was inhibited in response to whole cranberry extract and to a lesser degree by the proanthocyanidin fractions. Copyright © 2005 Society of Chemical Industry     

Improving Success in a Veterans Homeless Domiciliary Vocational Program: Model Development and Evaluation.

Objective: Determine predictors of success in a vocational rehabilitation component of a Veterans Affairs Rehabilitation Program. Design: The 1st of 2 experiments evaluated risk factors for failure to find competitive employment. The 2nd assessed attainment of employment following program changes based on identified risk factors. Participants: Eighty-four and 82 homeless veterans in Experiments 1 and 2, respectively. Results/Experiment 1: Eight factors were found to be significant and were combined into a Risk Factor Scale. Results/Experiment 2: The authors assigned patients to a competitive job-search-only track or a hybrid program combining competitive job search and the potential for supported employment. Overall employment rates increased, and success rates for those seeking only competitive employment rose. Employment rates of those unlikely to find competitive employment increased. Conclusion: Findings demonstrated the effect of developing systematic data on risk factors for failing to find employment, implementing changes based on the data, and applying the benefit of these changes to program functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of increased social support and lifestyle behaviors in a domiciliary for homeless veterans.

For improvement of the psychosocial rehabilitation environment of a homeless Domiciliary Residential Rehabilitation and Treatment Program (DOM-RRTP), increases in lifestyle behaviors (e.g., recreation, social, spiritual/coping, and educational) and altruistic activities (e.g., helping others on the unit or in the community) were targeted. With the use of contingency management in a quasi-experimental design, homeless residents were encouraged to engage in higher rates of desired behaviors. The treatment environment was reported by 66 veterans during a baseline analyses and 35 after the contingency management program was implemented. After the implementation of the contingency management program, a significant increase in healthy lifestyle and altruistic behaviors was observed. Furthermore, comparing patients' perceptions pre- and postimplementation showed significant improvement in the psychosocial rehabilitation environment in both expected areas (e.g., supportiveness) and unexpected areas (e.g., anger and aggression, program clarity). Overall, the study revealed improvements in the number of healthy lifestyle behaviors, and altruistic activities covaried with improvement in the overall rehabilitation environment. Limitations and implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonemic storage of concrete and abstract words with auditory presentation.

Conducted 2 experiments in which Ss' recognition memory for aurally presented concrete and abstract nouns was tested. In Exp I, 56 undergraduates heard study and test lists of 20 concrete and abstract nouns. The test list contained the same 20 nouns plus 20 new nouns which rhymed or did not rhyme with the study stimuli. In Exp II, 56 new undergraduates heard the same lists as in Exp I, but also heard lists in which concrete distractors rhymed with abstract study items and vice versa. Results show that false recognition depends upon the phonemic similarity of distractors to study words, and that the effect is independent of the concreteness of the words or whether the distractor matches the study word in concreteness. While the results may be inconsistent with aspects of the dual process theory of verbal coding, they may indicate that learners use phonemic attributes for recognition when imaginal attributes are insufficient. The appearance of an overall effect of concreteness on false alarms indicates that auditory presentation can produce imagery codes. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)