Reproducibility and validity of a novel invasive method of assessing peripheral microvascular vasomotor function.

In healthy arteries, blood flow is regulated by microvascular tone assessed by changes in blood flow volume and vascular resistance to endothelium-dependent and -independent vasodilators. We developed a novel method of using intravascular ultrasound (IVUS) and a Doppler flow wire to measure changes in blood flow volume and vascular resistance of the profunda arterial bed. We assessed the variability over 6 months in measuring microvascular endothelium-dependent dilation to acetylcholine and endothelium-independent dilation to adenosine in 20 subjects who were part of a larger study of Gulf War Illness without obstructive peripheral artery disease. Vasomotor function was assessed by Infusions of control (dextrose), acetylcholine (10-6M), adenosine (50µg), and nitroglycerin (25µg/ml). 400 IVUS and 240 flow velocity images were measured a mean 6 (SD = 2) months apart blind to measurement and infusion stage. The mean (SD) baseline profunda flow was 227 (172) ml/min and vascular resistance 4.6 x 104 (2.4 x 104) dynes-s/cm5. The intraclass correlation coefficients for 6-month variability for vascular function were excellent (range 0.827-0.995). Bland-Altman analyses showed mean differences of less than 2% for microvascular endothelium-dependent function (flow volume and resistance) and less than 1% for macrovascular endothelium-dependent function with acceptable limits of agreement. In 49 subjects assessing concurrent validity of the technique against atherosclerosis risk factors, we observed greater impairment in microvascular endothelium-dependent function per year of age (flow volume = -1.4% (p = 0.018), vascular resistance = 1.5% (p = 0.015)) and current smoking (flow volume = -36.7% (p = .006), vascular resistance = 50.0% (p<0.001)). This novel method of assessing microvascular vasomotor function had acceptable measurement reproducibility and validity.

Narcissism and adjustment in preadolescence.

Narcissism-a strong need to be admired for a grandiose self-is a problematic personality trait for children as well as adults. This study of 236 preadolescents (M age = 11.3 years; 129 girls, 107 boys) evaluated 2 intrapersonal (cognitive) pathways by which narcissism might contribute to maladjustment. The first was that narcissism combines with salient self-serving gender stereotypes to encourage aggressive and selfish behavior. The second was that narcissism places children who perceive that they are failing to realize their grandiose self at risk for aggression and depression. Although concurrent-correlational, the data support the pathways, illuminate the content and dynamics of narcissistic children's minds, and suggest directions for future investigation.

The intrapsychics of gender: a model of self-socialization.

This article outlines a model of the structure and the dynamics of gender cognition in childhood. The model incorporates 3 hypotheses featured in different contemporary theories of childhood gender cognition and unites them under a single theoretical framework. Adapted from Greenwald et al. (2002), the model distinguishes three constructs: gender identity, gender stereotypes, and attribute self-perceptions. The model specifies 3 causal processes among the constructs: Gender identity and stereotypes interactively influence attribute self-perceptions (stereotype emulation hypothesis); gender identity and attribute self-perceptions interactively influence gender stereotypes (stereotype construction hypothesis); and gender stereotypes and attribute self-perceptions interactively influence identity (identity construction hypothesis). The model resolves nagging ambiguities in terminology, organizes diverse hypotheses and empirical findings under a unifying conceptual umbrella, and stimulates many new research directions.

The developmental costs of high self-esteem for antisocial children.

Two hypotheses--high self-esteem leads children to act on antisocial cognitions (disposition-activating hypothesis) and high self-esteem leads children to rationalize antisocial conduct (disposition-rationalizing hypothesis)--were investigated in two longitudinal studies. In Study 1 (N= 189; mean age = 11.1 years), antisocial behavior was aggression; in Study 2 (N= 407; mean age = 10.8 years) it was avoidance of the mother. In both studies, there was little evidence for the disposition-activating hypothesis but considerable support for the disposition-rationalizing hypothesis. Over time, aggressive children with high self-esteem increasingly valued the rewards that aggression offers and belittled their victims, and avoidant children with high self-esteem increasingly viewed their mother as harassing and uninvolved. For antisocial children, high self-esteem carries costs.