Plasma matrix metalloproteinase-9 response to downhill running in humans.

Matrix metalloproteinase-9 is a proteolytic enzyme capable of degrading proteins of the muscle extracellular matrix. Systemic levels of MMP-9 or its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), have the potential to serve as blood markers of exercise-induced muscle damage. The purpose of this study was to determine if an eccentrically-dominated task, downhill running (DHR), produces changes in plasma MMP-9 or TIMP-1 and examine the relationship between MMP-9/TIMP-1 levels and indirect indicators of muscle damage. Subjects were sedentary (SED, n=12) or had a history of concentrically-biased training (CON, n=9). MMP-9 and TIMP-1 were measured before (Pre-Ex), immediately after (Post-Ex), and 1-, 2-, 4-, and 7-days post-DHR (-10°), and compared to discomfort ratings, creatine kinase activity and strength loss. At 1-day Post-Ex, discomfort increased (5.6 ± 7.8 to 45.5 ± 19.9 mm; 0-100 mm scale), strength decreased (-6.9 ± 1.6%) and CK increased (162.9 ± 177.2%). MMP-9 was modestly but significantly increased at Post-Ex in both CONC and SED (32.7 ± 33.6%) and at 4-days in SED (66.9 ± 88.1%), Individual responses were variable, however. There were no correlations between MMPs and discomfort ratings, plasma CK or strength. While plasma MMP-9 changes may be detectable in the systemic circulation after DHR, they are small and do not correspond to other markers of damage.

1 alpha,25-Dihydroxy-16-ene-23-yne-26,27-hexafluorocholecalciferol (Ro24-5531), a new deltanoid (vitamin D analogue) for prevention of breast cancer in the rat.

We have used the vitamin D analogue, 1 alpha,25-dihydroxy-16-ene-23-yne-26,27-hexafluorocholecalcifero l (Ro24-5531), for inhibition of mammary carcinogenesis induced by N-nitroso-N-methylurea (NMU) in Sprague-Dawley rats. Rats were first treated with a single dose of either 15 or 50 mg/kg body weight NMU and then fed Ro24-5531 (2.5 or 1.25 nmol/kg of diet) for 5-7 months. Ro24-5531 significantly extended tumor latency and lessened tumor incidence as well as tumor number in rats treated with the lower dose of NMU. In rats treated with the higher dose of NMU, Ro24-5531 was fed in combination with tamoxifen; in these experiments, Ro24-5531 significantly enhanced the ability of tamoxifen to reduce total tumor burden, as well as to increase the probability that an animal would be tumor free at the end of the experiment. In vitro, Ro24-5531 was 10-100 times more potent than 1,25-dihydroxyvitamin D3 for inhibition of proliferation of human breast cancer cell lines as well as primary cultures of cells from 2 patients with acute myelogenous leukemia. When fed chronically, Ro24-5531 did not elevate serum calcium in the present studies. We propose the new term, "deltanoids," for the set of molecules composed of vitamin D and its synthetic analogues, in a manner similar to the naming of "retinoids" for the corresponding set of molecules related to vitamin A.

Unexpected reading precocity in a normal preschooler: implications for hyperlexia.

This is a case study of a left-handed, preschool boy of superior intelligence who read very early and at a level well beyond what his IQ would predict. He is developmentally normal with no signs of autism or related disorders. His reading age was 9.3 at age 2-11 and 11.2 at 4-2; these levels are considerably beyond what would be predicted by his IQ or language age. He was able to read nonwords and both regular and irregular words equally well, indicating his mechanisms of lexical access in reading are similar to those of normal readers. Unlike classical hyperlexics, his reading comprehension for both single words and sentences was well above age level. When his precocious reading first appeared, he was also advanced in reading-related linguistic skills, such as phoneme awareness, auditory verbal short-term memory, and word retrieval, but not in visuospatial skills. These results imply that neither pathological language and/or social development, nor pathological variation in the normal mechanisms of lexical access in reading are necessary causes for reading precocity in early childhood. A model for integrating subtypes of precocious readers with subtypes of normal and dyslexic readers is proposed.

Word recognition and comprehension skills in hyperlexic children.

Five hyperlexic boys (4-5 to 10-1 years), who had been diagnosed with infantile autism or pervasive developmental delay in early childhood, were evaluated. Measures of intelligence, single-word recognition and comprehension, and picture naming were administered to determine the precocity or deficiency of reading recognition and comprehension, the underlying mechanisms of oral reading, and possible parallels with the acquired dyslexia subtypes. The results indicated that hyperlexia may be operationalized as unexpected reading precocity as compared to IQ; however, reading comprehension was not unexpectedly deficient. The phonological route to reading appeared to be preferred to the lexical route, and the overall pattern of performance most closely paralleled that of the surface dyslexic subtype.

The development and preliminary validation of the Tower of Hanoi-revised.

The objective of this study was to redesign the Tower of Hanoi (TOH) in order to increase the reliability and explore the validity of the task. In order to achieve this goal, a two-phase process was undertaken. In Phase 1, the TOH item pool was enlarged from 12 items to 60 items, and the task was administered to a sample of college students (N = 81). The 22 most homogeneous items for the final task were identified based on the item-total correlations. In Phase 2, the rebuilt TOH (TOH-R) was administered to a second sample (N = 50). The internal consistency reliability (Cronbach alpha) was .77 for this new sample. In this phase, the TOH-R was administered concurrently with the Tower of London-Revised (TOL-R), and the convergent validity of the TOH-R against the TOL-R was .53.

Towers of Hanoi and London: Reliability and Validity of Two Executive Function Tasks.

The Towers of Hanoi and London are presumed to measure executive functions such as planning and working memory. Both have been used as a putative assessment of frontal lobe function. In this study, both tasks were administered to 61 normal adult participants to test the assumption that the two tasks are measuring the same cognitive processes. The results revealed a significant, but relatively low (.37) correlation between performances on the two tasks. Follow-up analyses indicated that the likely source of the lack of convergence was the unreliability of the Tower of London. Thus, the common assumption that the two tasks are isomorphic must be questioned.

Development of the Tower of London-Revised.

The objective of this work was to reconstruct the Tower of London (TOL) test in order to increase its reliability. A three-phase process was undertaken to accomplish this goal. In Phase 1, the TOL item pool was increased, the task was administered to a sample of college students (N = 50), and item-total correlations were calculated in order to identify the items that had the highest correlation with the total score. In Phase 2, the revised 30-item TOL (TOL-R) was administered to a second sample (N = 50) and the internal consistency reliability (Chronbach alpha) was estimated at. 794. Finally, Phase 3 examined the test-retest reliability of the TOH-R on a new sample (N = 34) and the stability was found to be acceptable at r =.70.

Effects of consistent aerobic exercise on the psychological functioning of women.

Effects of consistent aerobic exercise on depression, anxiety, and health locus of control for a group of nonclinical inactive women were investigated. Type A and Type H (hard-driving) behavioral styles were evaluated to determine whether these traits were related to exercise improvement. 26 women were randomly assigned to either an exercise group (n = 10) or exercise with cognitive strategy instructions (n = 16). All subjects increased distance run in 12-min. run test from pre- to posttest. Women improved in depression and trait anxiety. Depression was significantly correlated with body mass index at end of program. Posttest state-anxiety was significantly correlated with 6-wk. follow-up of exercise frequency. No significant difference in pre- and posttest health locus of control was found. Type H scores were significantly correlated with number of exercise sessions attended. Consistent aerobic exercise had a positive effect on psychological functioning, and some characteristics may affect exercise improvement.

Aging and executive function skills: an examination of a community-dwelling older adult population.

The purpose of the present study was to employ the Tower of Hanoi task to the study of possible changes in executive function skills in older adults. The study used a quasi-experimental design, with age group (i.e., young adult, young elderly, or older elderly), being the independent variable in examining performance differences between younger and older adults. Data were analyzed cross-sectionally by age group. Nineteen elderly men and women comprised two groups; nine Young Elderly with an average age of 65 years and ten Older Elderly with an average age of 75 years. Two men and ten women served as a Young Adult comparison group having an average age of 19 years. Performance on the Tower of Hanoi was measured by efficiency scores (number of trials to consecutive solutions), frequency of error types, self-correction scores (completing the goal configuration in twenty or fewer moves after committing an error precluding a "correct" solution), and error perseveration (committing the same error on two consecutive trials of a problem). Analysis of variance and chi-squared tests suggested similar executive capacities among the 9 young adult and the 8 young elderly participants as compared to their 7 older elderly peers on the 3-disk task. However, on the 4-disk task where problem complexity increased by the addition of another disk and longer move sequences, young adult participants showed superior performance on the average than either young elderly or older elderly participants. Although the present study is limited by the small sample size and the use of cross-sectional analyses to examine age differences, these findings are consistent with the hypothesis of age differences in executive function.

Towers of Hanoi and London: is the nonshared variance due to differences in task administration?

Although it has been assumed that the Tower of Hanoi and Tower of London are more or less interchangeable tasks dependent on executive function, a series of studies in our laboratory have indicated substantial nonshared variance between the performances on the two tasks. The purpose of the present study was to examine how much methods of administration, such as number of trials per problem, contribute to this nonshared variance. A new one-trial version of the Tower of Hanoi was developed to be identical to the Tower of London in four procedural characteristics. The one-trial version of the Tower of Hanoi was administered to 39 normal adults along with the traditional Tower of Hanoi and the Tower of London-Revised in two test sessions 5-7 weeks apart. The correlations between the two tasks were in the same range as found previously with the traditional task, indicating that administration differences do not account for the nonshared variance between the tasks. A reliability analysis of the one-trial tasks showed poor internal consistency. Also, the internal consistency of the 6-trial tower was artificially inflated by aspects of the administration and scoring procedures. Moreover, this task exhibited a ceiling effect on repeated testing. These results suggest that it would be of value to redesign the one-trial Tower of Hanoi systematically to increase its reliability and, potentially, its validity as a measure of executive functions.

Aerobic exercise in the psychological treatment of adolescents.

A small group of psychiatrically institutionalized adolescents (16 boys, 11 girls) were assigned to a three-day-per-week running/aerobic exercise program or a regular physical activity class. The complete program continued over 9 weeks, with 11 subjects remaining throughout the program. Dependent measures of body-mass index, timed performance on a one-mile run, resting, exercise, and recovery heart rates, and measures of depression, mood-states, and self-efficacy were assessed pre-, mid-, and post-9-wk. treatment and at a 4-wk. follow-up. Improvements in depression, anxiety, hostility, confused thinking, and fatigue were shown in treated girls, with increases in vigor and self-efficacy for all treated subjects.

Cognitive strategies and personality variables in adherence to exercise.

Variables associated with adherence to a 6-wk jogging program were examined in a group of 26 ++sedentary women, who received instruction and reinforcement for their efforts: one group of 16 received instruction in cognitive self-statements; the other group of 10 did not. Measures included a battery of psychological questionnaires, percentage of body fat, weight, height, and distance run in a 12-min. test. Subjects maintained logs in which they recorded frequency and duration of exercise. Follow-up data were collected at 6-wk. and 6=mo. postprogram. Initial compliance was related to scores on the Self-motivation Inventory, the Type H (Hard-driving) scale of the Jenkins Activity Survey, and the State Anxiety Scale. At 6-mo. follow-up, none of the measures were significantly correlated with exercise frequency.

Sex differences in health attitudes and choice of health behaviors.

College students (82 men, 166 women) were assessed on a variety of physical fitness measures and completed questionnaires regarding health behaviors and attitudes. The men's health behaviors focused on physical activity while women's focused on dietary changes for better health.

Narcissism and causal attribution.

This study examined the relationship between scores on narcissistic personality traits and causal attributions to positive and negative events. 119 undergraduate students in psychology as participants completed the Narcissistic Personality Inventory-40, the Attributional Style Questionnaire, and several Self-referencing Closed-ended Vignettes. Analyses indicated that men who scored higher on the Narcissistic Personality Inventory-40 made more internal and stable attributions to positive events and more external and unstable attributions to negative events than did men who scored lower on the Narcissistic Personality Inventory-40. Also scores on the Self-referencing Closed-ended Vignettes correlated significantly and positively with the Attributional Style Questionnaire, providing evidence for the validity of the vignettes.

A prefrontal dysfunction model of early-treated phenylketonuria.

A prefrontal dysfunction model of early-treated phenylketonuria (PKU) is discussed. The biochemical perturbations caused by this genetic disorder have been found to result in depleted dopamine, a neurochemical that is critical for prefrontal cortical function. Studies of the neuropsychological sequelae of early-treated PKU in children are reviewed, and it is suggested that findings indicating executive function (EF) impairments are consistent with the prefrontal dysfunction hypothesis. An alternative model of the neuropsychological effects, that of a lefthemisphere dysfunction, is also discussed. Although a substantial amount of research has explored the neuropsychological performance of children with early-treated PKU, the extent to which these EF deficits are maintained into adolescence and adulthood is unclear. The neuropsychological expression of early-treated PKU across development requires further investigation and should provide a window on the general nature of brain development and function.

Towers of Hanoi and London: contribution of working memory and inhibition to performance.

The Tower of Hanoi and Tower of London have become well-established executive function tasks that presumably tap cognitive skills mediated by the frontal cortex. It has been assumed that the two tower tasks are more or less interchangeable and that both measure working memory and inhibition processes. These assumptions were tested in a study involving 37 normal college volunteers (M age = 20 years). Participants were administered the Tower of Hanoi (TOH), Tower of London-Revised (TOL-R), two working memory tests, and two tests of inhibition. The two tower tasks correlated significantly (r = .39), but only moderately. The working memory and inhibition variables explained over one-half of the variance in TOL-R performance; however, there was a relatively weaker contribution of inhibition to TOH performance.

Neuropsychology of early-treated phenylketonuria: specific executive function deficits.

This study explored the hypothesis that children with early-treated phenylketonuria (PKU) are selectively impaired on executive function measures, even when still on diet. The rationale for this hypothesis is that even mild elevations in phenylalanine (Phe) can lead to lower central levels of biogenic amines, including dopamine (DA). We hypothesize that this mild DA depletion causes subtle prefrontal dysfunction, which in turn affects executive functions such as set maintenance, planning, and organized search. 11 preschool early-treated PKU children (M age = 4.64) and a sample of age- and IQ-matched unaffected peers (n = 11) were evaluated on a battery of executive function (EF) measures. In addition, a "non-executive function" task, recognition memory, was administered to all subjects. Group comparisons demonstrated that PKU children were significantly impaired on an executive function composite score; there were no group differences, however, in recognition memory. These results supported the hypothesized specific deficit in executive function. Furthermore, within the PKU group the executive function composite score was significantly negatively correlated with concurrent phenylalanine levels, even after controlling for the correlation between IQ and executive function skills. This second finding provides support for the proposed biochemical mechanism underlying the specific cognitive deficits.