Vitamin D status of adults from tropical Australia determined using two different laboratory assays: implications for public health messages.

We measured serum 25 hydroxyvitamin D [25(OH)D] levels of ambulatory adults in tropical Australia to determine whether it is appropriate to continue promoting sun-safety in this population. In August 2006 (winter), self-administered questionnaires were completed by 145 Meals-on-Wheels volunteers (49.3% male; mean age 57.8 ± 14.7 years; 76.6% response) from Townsville, Queensland (Latitude 19(o) S). Serum 25(OH)D was analyzed using two common assays. Mean levels were 68.3 (SD ± 18.7; range 26-142) by DiaSorin Radioimmunoassay and 83.0 (SD ± 30.8; range 30-184) by DiaSorin Liaison® one. No participants were 25(OH)D deficient (<25 nmol L(-1)). Nine participants (6.2%) had 25(OH)D levels between 25 and 50 nmol L(-1) (insufficient), by both methods (seven with a BMI ≥ 25). Twenty-eight participants (19.3%) had one result in the insufficient range and the other in the adequate range. Thus, almost all of these free-living adults in tropical Australia had adequate vitamin D levels at the end of winter. There was poor agreement between the two 25(OH)D assays. These results suggest it is appropriate to continue promoting sun-safe messages to the ambulatory Caucasian adult population of North Queensland, which has an extremely high incidence of skin cancer. The lack of agreement between the two assays is a concern. Few doctors are aware of this measurement issue.

The rising prevalence of comorbid obesity and eating disorder behaviors from 1995 to 2005.

OBJECTIVE: To measure the cooccurrence of obesity and eating disorder (ED) behaviors in the South Australian population and assess the change in level from 1995 to 2005. METHOD: Two independent cross-sectional single stage interview based population surveys were conducted a decade apart. Self-reported height, weight, ED behaviors, and sociodemographics were assessed. Changes between the two time points were analyzed. RESULTS: From 1995 to 2005 the population prevalence of comorbid obesity and ED behaviors increased from 1 to 3.5%. Comorbid obesity and ED behaviors increased more (prevalence odds ratio (POR) = 4.5; 95% confidence interval (CI) = 95% CI = [2.8, 7.4]; p < .001) than either obesity (POR = 1.6; 95% CI = [1.3, 2.0]; p < .001) or ED behaviors (POR = 3.1; 95% CI = [2.3, 4.1]; p < .001) alone. DISCUSSION: Comorbid obesity and ED behaviors are an increasing problem in our society. Prevention and treatments efforts for obesity and EDs must consider and address this increasing comorbidity.

The Ashman phenomenon.

In the presence of atrial fibrillation, impulses of supraventricular origin that are transmitted through the ventricles during periods of relative refractoriness to impulse conduction exhibit anomalous configurations. These "aberrant beats" can be difficult to distinguish from ventricular ectopic beats, and groups of aberrant beats may be mistaken for ventricular tachycardia. Richard Ashman, PhD, a physiologist at Louisiana State University School of Medicine in New Orleans, noted that ventricular refractoriness varied with the lengths of cardiac cycles; that aberrant beats typically ended short cycles following long cycles; and that aberrant beats often have a right bundle branch block configuration. This observation, known as the "Ashman phenomenon," has become a principle of cardiology. Its recognition may allow clinicians to distinguish aberrant beats from ventricular ectopy. Ashman made a variety of other fundamental contributions to electrocardiography and was also an accomplished poet.

Optic nerve head segmentation.

Reliable and efficient optic disk localization and segmentation are important tasks in automated retinal screening. General-purpose edge detection algorithms often fail to segment the optic disk due to fuzzy boundaries, inconsistent image contrast or missing edge features. This paper presents an algorithm for the localization and segmentation of the optic nerve head boundary in low-resolution images (about 20 microns/pixel). Optic disk localization is achieved using specialized template matching, and segmentation by a deformable contour model. The latter uses a global elliptical model and a local deformable model with variable edge-strength dependent stiffness. The algorithm is evaluated against a randomly selected database of 100 images from a diabetic screening programme. Ten images were classified as unusable; the others were of variable quality. The localization algorithm succeeded on all bar one usable image; the contour estimation algorithm was qualitatively assessed by an ophthalmologist as having Excellent-Fair performance in 83% of cases, and performs well even on blurred images.