Diagnostic accuracy and variability of autorefraction by the Tracey Visual Function Analyzer and the Shin-Nippon NVision-K 5001 in relation to subjective refraction

Purpose:  To determine the accuracy of distance autorefractions obtained by two 'open field' devices, the Tracey Visual Function Analyzer and the Shin-Nippon NVision-K 5001, by comparison with subjective refraction.
Methods:  Both eyes of 50 healthy phakic participants underwent subjective refraction. Autorefractions were then performed on undilated pupils using the Tracey and a modified Shin-Nippon autorefractor and these were repeated within 50 days. Agreement with subjective refraction was calculated for sphere, mean spherical equivalent (MSE) and cylindrical vectors J ₀ and J ₄₅. Intratest and intertest variability were also evaluated.
Results:  The mean age of the participants was 37.4 years. Subjective refraction MSE ranged from −6.25 D to +3.62 D, mean −0.49 D ± 1.79 D. Bias between subjective refraction and Tracey was −0.001 D, +0.045 D, +0.017 D, and −0.015 D for sphere, MSE, J ₀ and J ₄₅ respectively; these were not significant. Bias between subjective refraction and Shin-Nippon was +0.004 D, +0.033 D, +0.106 D, and −0.021 D; only the J ₀ vector was significantly different ( p  < 0.0001) although this difference was small. Intratest variability for Tracey was low, measured at 0.189 D for sphere and 0.178 for MSE, and for the Shin-Nippon 0.099 D and 0.086 D respectively. Tracey intertest variability revealed small, statistically significant bias for sphere and MSE (+0.071 D and +0.070 D, p  = 0.011, 0.013). Shin-Nippon reproducibility showed no significant bias.
Conclusions:  Autorefraction measurements captured by both the Tracey and Shin-Nippon devices agree well with subjective refraction. The Shin-Nippon shows lower intratest variability.     

Blood pressure and retinopathy in type I diabetes

The relationship between blood pressure and diabetic retinopathy was evaluated in 249 young subjects with type I diabetes. Although hypertension is known to be associated with an increased risk for retinopathy, the effects of high-normal blood pressure are unknown. Retinopathy (158 of 249 subjects, 63%) is considerably more common in a young diabetic population than is hypertension (7 of 249 subjects, 2%). Thus, if blood pressure is important in the etiology or progression of diabetic retinopathy, levels below the hypertensive range (less than 141/90 mmHg) must be considered. The combined effect of hypertension and high-normal blood pressure (greater than 90th percentile but less than 141/90 mmHg) was studied. Elevation in diastolic blood pressure, alone, and in combination with elevated systolic blood pressure, correlated significantly (P less than 0.03) with retinopathy. The presence of high-normal blood pressure resulted in a prospectively higher occurrence of retinopathy and of progression of preexisting retinopathy. Glycohemoglobin (HbA1) and duration of diabetes also correlated with retinopathy. Both good glycemic control and maintenance of diastolic blood pressure below the 90th percentile for age may be important in relation to diabetic retinopathy.     

Species-dependent differences in the properties of particulate cyclic nucleotide phosphodiesterase from rat and rabbit ventricular myocardium

The ability of cyclic nucleotide phosphodiesterases (PDEs) to hydrolyse cyclic (c)AMP in rat and rabbit ventricular myocardium has been compared. The PDE activity of rabbit, but not rat, cardiac homogenate and supernatant fraction was potentiated by Ca2+/calmodulin and attenuated by cGMP. Both rabbit and rat ventricular myocardium were shown to have a membrane bound PDE. However, rabbit membrane-bound PDE was inhibited by cGMP and low concentrations of milrinone (IC50 2.7 microM). In contrast, rat membrane-bound PDE was not inhibited by either cGMP or low concentrations of milrinone (IC50 19 microM), but it was potently inhibited by rolipram (IC50 2.2 microM). Thus, in rabbit the particulate PDE is milrinone sensitive (PDE III) whilst in rat it is the rolipram sensitive (PDE IV) isoenzyme. There are clearly species differences in the intracellular localization and relative activities of PDE isoenzymes in cardiac tissue. This may explain the species differences already found in the activity of selective PDE isoenzyme inhibitors as inotropic agents.     

Poxvirus-based vaccine therapy for patients with advanced pancreatic cancer

Purpose  

An open-label Phase 1 study of recombinant prime-boost poxviruses targeting CEA and MUC-1 in patients with advanced pancreatic cancer was conducted to determine safety, tolerability and obtain preliminary data on immune response and survival.     

Population-based randomized controlled trial of a stage-targeted physical activity intervention

Background: Intervention trials with self-selected participants have shown that mailed stage-targeted print materials can increase participation in physical activity in the short term. We examined the effects of a mailed stage-targeted print intervention designed to promote physical activity, in a random sample of adults living in a regional city.Method: Participants (n = 462, 40–60 years of age) were randomly allocated to an intervention in - 227) or control group (n - 235). Measures included validated 2-week physical activity recall and stage of motivational readiness for physical activity. The intervention consisted of a single mailing of a letter and full-color stage-targeted booklets (specific to precontemplation, contemplation, preparation, and action/maintenance) 1 week postbaseline. Follow-up interviews were conducted at 2 and 6 months postbaseline.Results: After 2 months, participants in the intervention group were significantly More likely to meet the current American College of Sports Medicine/Centers for Disease Control and Prevention recommendation for sufficient physical activity than those in the control group (adjusted odds ratio [OR] - 2.40; 95% confidence interval [CI] = 1.44–3.99). After 6 months, intervention participants who reported receiving and reading the intervention materials were significantly more likely to be meeting the sufficient physical activity criterion compared with the control group (adjusted OR = 2.03; 95% Cl = 1.16–3.56).Conclusions: The stage-targeted print intervention was effective in promoting short-term increases in physical activity and was most effective for participants who recognized and used the materials. This low-cost, generalizable intervention has demonstrated potential as a practical population-based physical activity promotion strategy. Further research is required before widespread dissemination would be justified, as additional strategies may be required to ensure sustained change. This project was supported by a National Heart Foundation of Australia Research Project Grant. David Crawford was supported by a Nutrition Research fellowship from the National Heart Foundation.