Synchrotron-based intravenous cerebral angiography in a small animal model

K-edge digital subtraction angiography (KEDSA), a recently developed synchrotron-based technique, utilizes monochromatic radiation and allows acquisition of high-quality angiography images after intravenous administration of contrast agent. We tested KEDSA for its suitability for intravenous cerebral angiography in an animal model. Adult male New Zealand rabbits were subjected to either angiography with conventional x-ray equipment or synchrotron-based intravenous KEDSA, using an iodine-based contrast agent. Angiography with conventional x-ray equipment after intra-arterial administration of contrast agent demonstrated the major intracranial vessels but no smaller branches. KEDSA was able to visualize the major intracranial vessels as well as smaller branches in both radiography mode (planar images) and tomography mode. Visualization was achieved with as little as 0.5 ml kg-1 of iodinated contrast material. We were able to obtain excellent visualization of the cerebral vasculature in an animal model using intravenous injection of contrast material, using synchrotron-based KEDSA.     

The effects of weight management programs on self-esteem in pediatric overweight populations

OBJECTIVE: Review published findings on self-esteem and pediatric overweight, and changes in self-esteem subsequent to weight management programs. METHODS: We used PsycInfo and MedLine searches to identify peer-reviewed journal articles examining self-esteem changes following participation in weight management programs. RESULTS: Data regarding the relationship between self-esteem and obesity is mixed. Factors that place overweight children "at-risk" for low self-esteem include early adolescence, female gender, identification with majority cultural standards of body shape, exposure to teasing and peer victimization, a history of greater parental control over feeding, and internal attributions about weight status. Data from intervention studies suggest positive effects on self-esteem across settings. Components related to self-esteem improvements include weight change, parent involvement, and group intervention format. CONCLUSIONS: Well-designed, longitudinal studies using multidimensional measures of self-esteem, and following CONSORT guidelines are needed to confirm and expand these findings. Emphasis should be placed on examining mediators and moderators of self-esteem change.     

Dynamics of response to perceptual pop-out stimuli in macaque V1

Contextual modulation due to feature contrast between the receptive field and surrounding region has been reported for numerous stimuli in primary visual cortex. One type of this modulation, iso-orientation surround suppression, has been studied extensively. The degree to which surround suppression is related to other forms of contextual modulation remains unknown. We used shape-from-shading stimuli in a field of distractors to test the latency and magnitude of contextual modulation to a stimulus that cannot be distinguished with an orientation-selective mechanism. This stimulus configuration readily elicits perceptual pop-out in human observers and induces a long-latency contextual modulation response in neurons in macaque early visual cortex. We found that animals trained to detect the location of a pop-out stimulus were better at finding a sphere that appeared to be lit from below in the presence of distractors that were lit from above. Furthermore, neuronal responses were stronger and had shorter latency in the condition where behavioral performance was best. This asymmetry is compatible with earlier psychophysical findings in human observers. In the population of V1 neurons, the latency of the contextual modulation response is 145 ms on average (ranging from 70 to 230 ms). This is much longer than the latency for iso-orientation surround suppression, indicating that the underlying circuitry is distinct. Our results support the idea that a feature-specific feedback signal generates the pop-out responses we observe and suggest that V1 neurons actively participate in the computation of perceptual salience.     

Trends in kidney transplantation rates and disparities

OBJECTIVE: To examine the likelihood of transplantation and trends over time among persons with end-stage renal disease (ESRD) in Wisconsin. METHODS: We examined the influence of patient- and community-level characteristics on the rate of kidney transplantation in Wisconsin among 22,387 patients diagnosed with ESRD between January 1, 1982 and October 30, 2005. We grouped patients by the year of ESRD onset in order to model the change in transplantation rates over time. RESULTS: After multivariate adjustment, all other racial groups were significantly less likely to be transplanted compared with whites, and the racial disparity increased over calendar time. Older patients were less likely to be transplanted in all periods. Higher community income and education level and a greater distance from patients' residence to the nearest dialysis center significantly increased the likelihood of transplantation. Males also had a significantly higher rate of transplantation than females. CONCLUSION: These results demonstrate a growing disparity in transplantation rates by demographic characteristics and a consistent disparity in transplantation by socioeconomic characteristics. Future studies should focus on identifying specific barriers to transplantation among different subpopulations in order to target effective interventions.     

Grape polyphenols corrects ageing-related detriments in neutrophil functionality via modulation of specific molecular targets

Oxidative stress and inflammation are intricately interlinked as aetiological factors in the context of ageing and chronic disease-related accelerated ageing. Previous research by our group has highlighted the anti-oxidant and anti-inflammatory potential of grape-derived polyphenols in the context of acute inflammation and oxidative stress. The aim here was to add to this by assessing efficacy of the treatment (acutely) to address ageing-associated cumulative pro-oxidant and pro-inflammatory changes in an in vitro model. Blood from young and aged humans was analysed for baseline oxidative stress and inflammatory status. Isolated neutrophils were acutely exposed to the polyphenol treatment in vitro. The chemokinetic capacity of treated and control neutrophils in response to fMLP was subsequently determined in a Dunn chamber, using live cell imaging. Neutrophils were also analysed for the expression of selected molecular markers associated with functional capacity and oxidative stress. Results indicate that the aged population had significantly worse oxidative stress and inflammatory profiles (higher plasma conjugated dienes and MPO) than young controls. Neutrophils isolated from both young and aged individuals had improved chemokinetic accuracy and capacity after in vitro polyphenol treatment. Additionally, increased shedding of CD16 and expression of CD66b suggested sites via which the polyphenol achieved improved neutrophil motility. We conclude that grape seed-derived polyphenols facilitated improved neutrophil functionality by acting on the molecular targets elucidated here.     

Digital Promotion of Energy Drinks to Young Adults Is More Strongly Linked to Consumption Than Other Media

Objective

To examine whether digital marketing strategies are more strongly associated with energy drink use than other marketing and whether Theory of Planned Behavior (TPB) constructs mediated the effects of digital marketing on energy drink use.