Limitations of Rb-82 weight-adjusted dosing accuracy at low doses

Journal of Nuclear Cardiology - Weight-adjusted dosing is important to maintain accurate quantification for dynamic cardiac three-dimensional positron emission tomography (PET). However, the...     

Neurocognitive Treatments for Eating Disorders and Obesity

Purpose of Review

Recent research has highlighted executive function and neurocognitive deficits among individuals with eating and weight disorders, identifying a potential target for treatment. Treatments targeting executive function for eating and weight disorders are emerging. This review aims to summarize the recent literature evaluating neurocognitive/executive function-oriented treatments for eating and weight disorders and highlights additional work needed in this area.

Recent Findings

Cognitive remediation therapy (CRT) for anorexia nervosa has been the most extensively studied neurocognitive treatment for eating disorders. Results demonstrate that CRT improves executive function and may aid in the reduction of eating disorder symptomatology. Computer training programs targeting modifying attention and increasing inhibition are targeting reduction of binge eating and weight loss with modest success.

Summary

Neurocognitive treatments are emerging and show initial promise for eating and weight disorders. Further research is necessary to determine whether these treatments can be used as stand-alone treatments or whether they need to be used as an adjunct to or in conjunction with other evidence-based treatments to improve outcomes.

     

Vehicular air pollution, playgrounds, and youth athletic fields

In spite of epidemiological evidence concerning vehicular air pollution and adverse respiratory/cardiovascular health, many athletic fields and school playgrounds are adjacent to high traffic roadways and could present long-term health risks for exercising children and young adults. Particulate matter (PM(1),0.02-1.0 microm diameter) number counts were taken serially at four elementary school athletic/playground fields and at one university soccer field. Elementary school PM1 measurements were taken over 17 days; measurements at the university soccer field were taken over 62 days. The high-traffic-location elementary school field demonstrated higher 17-day [PM1] than the moderate and 2 low traffic elementary school fields (48,890 +/- 34,260, 16,730 +/- 10,550, 11,960 +/- 6680, 10,030 +/- 6280, respective mean counts; p < .05). The 62-day mean PM1 values at the university soccer field ranged from 115,000 to 134,000 particles cm(-3). Lowest mean values were recorded at measurement sites furthest from the highway (approximately 34,000 particles cm(-3)) and followed a second-order logarithmic decay (R2 = .999) with distance away from the highway. Mean NO2 and SO2 levels were below 100 ppb, mean CO was 0.33 +/- 1.87 ppm, and mean O3 was 106 +/- 47 ppb. Ozone increased with rising temperature and was highest in the warmer afternoon hours (R = .61). Although the consequence of daily recess play and athletic activities by school children and young athletes in high ambient [PM1] conditions has not yet been clearly defined, this study is a critical component to evaluating functional effects of chronic combustion-derived PM exposure on these exercising schoolchildren and young adults. Future studies should examine threshold limits and mechanistic actions of real-world particle exposure.     

One year of oral calcium supplementation maintains cortical bone density in young adult female distance runners

We conducted a double-blind, placebo-controlled, randomized trial to determine whether 1 year of supplemental calcium intake would augment hip [greater trochanter, GT, femoral neck (FN), total hip (TH)], spine (LS), and femoral mid-shaft (Fmr) BMD in female distance runners. Twenty-three women (age: 23.7 +/- 4.7 yrs, height: 165.6 +/- 6.3 cm, weight: 55.7 +/- 6.1 kg) were randomly assigned to receive either 1000 mg/d of supplemental calcium (N = 13) or placebo tablets (N = 10) for 1 year. BMD was determined by DXA (Hologic 1000-W) and tablet compliance by self-report logs. Compliance averaged 79% and 71% for supplement and placebo groups, respectively. Calcium supplementation did not affect hip or spine BMD, but did prevent loss at the femoral mid-shaft (GT: -0.5% vs. 0.2%, FN: 0.9% vs. 1.1%, TH: -0.3% vs. 0.2%, LS: 0.3% vs. 1.2%, Fmr: 0.1% vs. -1.8%, for calcium vs. placebo, respectively). We conclude that the addition of 800 mg/d of supplemental calcium to the diet of young adult female distance runners with habitual calcium intakes of approximately 1000 mg/d, prevents cortical but not trabecular bone loss.     

Mapping the time course of nonconscious and conscious perception of fear: an integration of central and peripheral measures

Neuroimaging studies using backward masking suggest that conscious and nonconscious responses to complex signals of fear (facial expressions) occur via parallel cortical and subcortical circuits. Little is known, however, about the temporal differentiation of these responses. Psychophysics procedures were first used to determine objective thresholds for both nonconscious detection (face vs. blank screen) and discrimination (fear vs. neutral face) in a backward masking paradigm. Event-related potentials (ERPs) were then recorded (n = 20) using these thresholds. Ten blocks of masked fear and neutral faces were presented under each threshold condition. Simultaneously recorded skin conductance responses (SCRs) provided an independent index of stimulus perception. It was found that Fear stimuli evoked faster SCR rise times than did neutral stimuli across all conditions, indicating that emotional content influenced responses, regardless of awareness. In the first 400 msec of processing, ERPs dissociated the time course of conscious (enhanced N4 component) from nonconscious (enhanced N2 component) perception of fear, relative to neutral. Nonconscious detection of fear also elicited relatively faster P1 responses within 100 msec post-stimulus. The N2 may provide a temporal correlate of the initial sensory processing of salient facial configurations, which is enhanced when top-down cortical feedback is precluded. By contrast, the N4 may index the conscious integration of emotion stimuli in working memory, subserved by greater cortical engagement. Hum. Brain Mapping 21:64-74, 2004.