Structural violence, urban retail food markets, and low birth weight

This paper investigates urban retail food markets and health in Syracuse, New York. A structured observational analysis found that a majority of corner markets do not sell fresh produce or low fat dairy products, but conduct a lively business selling lottery tickets, cigarettes, and liquor. A comparison of census tracts with and without access to supermarkets that sell fresh produce and other healthy food found that pregnant women living in proximity to a supermarket had significantly fewer low birth weight births than other pregnant women regardless of income level.     

Placebo-controlled study examining effects of selegiline in children with attention-deficit/hyperactivity disorder

There is evidence suggesting a role for dopamine in attention-deficit/hyperactivity disorder (ADHD). Pharmacological treatments that act on the dopamine system have been successful in reducing ADHD symptoms. However, unlike traditional stimulants (i.e., methylphenidate), selegiline is a monoamine oxidase inhibitor (MAOI) that has been shown to reduce ADHD symptoms without producing undesirable side effects. In this study using a randomized, double- blind, placebo-controlled, crossover design, cognitive tasks and behavioral rating scales were administered to measure the effectiveness of selegiline in treating different symptoms of ADHD in 11 children aged 6-13. Results indicate that selegiline may target specific symptoms of ADHD including: sustained attention, the learning of novel information, hyperactivity, and peer interactions. Because the drug was not associated with negative side effects and did not specifically reduce symptoms of impulsivity, selegiline may be a preferred treatment for individuals who present with the primarily inattentive subtype of ADHD.     

Validation of novel imaging methodologies for use as cancer clinical trial end-points

The success or failure of a clinical trial, of any phase, depends critically on the choice of an appropriate primary end-point. In the setting of phases II and III cancer clinical trials, imaging end-points have historically, and continue presently to play a major role in determining therapeutic efficacy. The primary goal of this paper is to discuss the validation of imaging-based markers as end-points for phase II clinical trials of cancer therapy. Specifically, we outline the issues that must be considered, and the criteria that would need to be satisfied, for an imaging end-point to supplement or potentially replace RECIST- defined tumour status as a phase II clinical trial end-point. The key criteria proposed to judge the utility of a new end-point primarily relate to its ability to accurately and reproducibly predict the eventual phase III end-point for treatment effect, which is usually assessed by a difference between two arms on progression free or overall survival, both at the patient and more importantly at the trial level. As will be demonstrated, the level of evidence required to formally and fully validate a new imaging marker as an appropriate end-point for phase II trials is substantial. In many cases, this level of evidence will only become available by conducting a series of coordinated prospectively designed multicentre clinical trials culminating in a formal meta-analysis. We also include a discussion of situations where flexibility may be required, relative to the ideal rigorous evaluation, to accommodate inevitable real-world feasibility constraints.     

Relationship Between Behavioral and Physiological Spectral-Ripple Discrimination

Previous studies have found a significant correlation between spectral-ripple discrimination and speech and music perception in cochlear implant (CI) users. This relationship could be of use to clinicians and scientists who are interested in using spectral-ripple stimuli in the assessment and habilitation of CI users. However, previous psychoacoustic tasks used to assess spectral discrimination are not suitable for all populations, and it would be beneficial to develop methods that could be used to test all age ranges, including pediatric implant users. Additionally, it is important to understand how ripple stimuli are processed in the central auditory system and how their neural representation contributes to behavioral performance. For this reason, we developed a single-interval, yes/no paradigm that could potentially be used both behaviorally and electrophysiologically to estimate spectral-ripple threshold. In experiment 1, behavioral thresholds obtained using the single-interval method were compared to thresholds obtained using a previously established three-alternative forced-choice method. A significant correlation was found (r = 0.84, p = 0.0002) in 14 adult CI users. The spectral-ripple threshold obtained using the new method also correlated with speech perception in quiet and noise. In experiment 2, the effect of the number of vocoder-processing channels on the behavioral and physiological threshold in normal-hearing listeners was determined. Behavioral thresholds, using the new single-interval method, as well as cortical P1-N1-P2 responses changed as a function of the number of channels. Better behavioral and physiological performance (i.e., better discrimination ability at higher ripple densities) was observed as more channels added. In experiment 3, the relationship between behavioral and physiological data was examined. Amplitudes of the P1-N1-P2 “change” responses were significantly correlated with d′ values from the single-interval behavioral procedure. Results suggest that the single-interval procedure with spectral-ripple phase inversion in ongoing stimuli is a valid approach for measuring behavioral or physiological spectral resolution.     

Disruption of the D2 dopamine receptor alters GH and IGF-I secretion and causes dwarfism in male mice

We determined the consequences of the loss of D2 receptors (D2R) on the GH-IGF-I axis using mice deficient in functional dopamine D2 receptors by targeted mutagenesis (D2R(-/-)). Body weights were similar at birth, but somatic growth was less in male D2R(-/-) mice from 1-8 months of age and in D2R(-/-) females during the first 2 months. The rate of skeletal maturation, as indexed by femur length, and the weight of the liver and white adipose tissue were decreased in knockout male mice even though food intake was not altered. The serum GH concentration was significantly decreased during the first 2 months in knockout female and male mice, and IGF-I and IGF-binding protein-3 levels were lower in knockout mice. PRL was significantly higher in knockout mice, and females attained higher levels than males. Pituitaries from adult knockout mice had impaired basal GH release and a lower response to GHRH in vitro. We propose that the D2R participates in GHRH/GH release in the first month of life. In accordance, the D2R antagonist sulpiride lowered GH levels in 1-month-old wild-type mice. Our results indicate that lack of D2R alters the GHRH-GH-IGF-I axis, and impairs body growth and the somatotrope population.