Dietary enrichment with almond (Prunus amygdalis) supplementation: effects on CVD risk biomarkers

Epidemiological evidence suggests that diets rich in fruits, vegetables and pulses reduce the risk of CVD. The Physicians Health Study has demonstrated reduction of CHD death with regular nut consumption1. One major modifiable risk factor for CHD is an unhealthy diet. Thus, an almondenrichment study has been undertaken to examine the benefit of almonds (Prunus amygdalis) in healthy individuals either with or without significant risk of vascular disease. Almonds contain various macronutrients (low SFA content, absence of cholesterol and high MUFA content) and micronutrients, including vitamin E, polyphenols and arginine, which afford vascular benefit. The effects of almond consumption (25 g/d for 4 weeks followed by 50 g/d for 4 weeks) were evaluated in three non-smoking subject groups: healthy male volunteers between the ages of 18 and 35 years (n 15); men at risk of heart disease between the ages of 18 and 35 years (n 12); mature men and women >50 years of age (n 18). A fourth control group (n 14) were followed over 8 weeks without dietary almond enrichment as a treatment control. None of the subjects withdrew from the study and 90% completed the study. The interim results of the study showed that in the three active groups there was little evidence for a change in total cholesterol, LDL-cholesterol or HDL-cholesterol. In the mature group there was a trend towards increasing HDL-cholesterol. The mature and ‘at-risk’ groups also showed a significant changes in systolic blood pressure (P<0.05) during almond consumption. The healthy group showed a decrease in diastolic blood pressure (P<0.05). The ‘at-risk’ group showed a significant increase (P<0.05) in flowmediated dilation after 8 weeks of almond consumption. Data analysis is ongoing, with completion of the study in November 2007. The beneficial effects of almond consumption on flow-mediated dilation and blood pressure may be attributed to the high content in almonds of arginine, which serves as a precursor to the vasodilatory molecule, NO.

Clinical characteristics of unilateral myopic anisometropia in a juvenile optometric practice population

Purpose: A retrospective study of longitudinal case histories, undertaken to establish the clinical and statistical characteristics of unilateral myopic anisometropia (UMA) amongst the juvenile and adolescent population at an optometric practice, is reported. UMA was defined as that specific refractive state where an unequivocally myopic eye is paired with a 'piano' [spherical equivalent refraction, (SER) = ±0.25 Dioptres (D)] companion eye. Methods: The clinical records of all patients aged <19 years on file at an established independent optometric practice were categorised as 'myopic' (SER ≤-0.50 D), 'hypermetropie' (≥+0.75 D) or 'emmetropic' (≥-0.37≤+0.62 D). Subsequently all juvenile patients matching the UMA criterion, together with a case-matched group of bilaterally myopic individuals, were selected as the comparative study populations. Results: A total of 14.4% (n = 21 of 146) of the juvenile myopic case histories were identified as cases of UMA. More than half of these UMA cases emerged between the ages of 11.5 and 13.5 years. There was a marked female gender bias. The linear gradient of the age-related mean refractive trend in the myopic eye of the UMA population was not statistically significantly different (p > 0.1) to that fitted to the ametropic progression recorded in either eye of the case-matched population of young bilateral myopes; uniquely the slope associated with the companion eye of UMA cases was statistically significantly (p < 0.025) less steep. Compared with bilateral myopes fewer cases of UMA required a refractive correction to relieve visual or asthenopic symptoms, and this initial correction was dispensed on average 1 year later (at age 12.7 years) in UMA patients. Conclusions: Individuals identified as demonstrating clinically-defined UMA can be considered as distinct but functionally normal cases on the continuum of human refractive error. However, any unilaterally-acting determining factor(s) underlying the genesis of the condition remain obscure. © 2004 The College of Optometrists.

Design and validity of a miniaturized open-field aberrometer

PURPOSE: To validate a new miniaturised, open-field wavefront device which has been developed with the capacity to be attached to an ophthalmic surgical microscope or slit-lamp. SETTING: Solihull Hospital and Aston University, Birmingham, UK DESIGN: Comparative non-interventional study. METHODS: The dynamic range of the Aston Aberrometer was assessed using a calibrated model eye. The validity of the Aston Aberrometer was compared to a conventional desk mounted Shack-Hartmann aberrometer (Topcon KR1W) by measuring the refractive error and higher order aberrations of 75 dilated eyes with both instruments in random order. The Aston Aberrometer measurements were repeated five times to assess intra-session repeatability. Data was converted to vector form for analysis. RESULTS: The Aston Aberrometer had a large dynamic range of at least +21.0 D to -25.0 D. It gave similar measurements to a conventional aberrometer for mean spherical equivalent (mean difference ± 95% confidence interval: 0.02 ± 0.49D; correlation: r=0.995, p<0.001), astigmatic components (J0: 0.02 ± 0.15D; r=0.977, p<0.001; J45: 0.03 ± 0.28; r=0.666, p<0.001) and higher order aberrations RMS (0.02 ± 0.20D; r=0.620, p<0.001). Intraclass correlation coefficient assessments of intra-sessional repeatability for the Aston Aberrometer were excellent (spherical equivalent =1.000, p<0.001; astigmatic components J0 =0.998, p<0.001, J45=0.980, p<0.01; higher order aberrations RMS =0.961, p<0.001). CONCLUSIONS: The Aston Aberrometer gives valid and repeatable measures of refractive error and higher order aberrations over a large range. As it is able to measure continuously, it can provide direct feedback to surgeons during intraocular lens implantations and corneal surgery as to the optical status of the visual system.

Ash control methods to limit biomass inorganic content and its effect on fast pyrolysis bio-oil stability

This research investigates specific ash control methods to limit inorganic content within biomass prior to fast pyrolysis and effect of specific ash components on fast pyrolysis processing, mass balance yields and bio-oil quality and stability. Inorganic content in miscanthus was naturally reduced over the winter period from June (7.36 wt. %) to February (2.80 wt. %) due to a combination of senescence and natural leaching from rain water. September harvest produced similar mass balance yields, bio-oil quality and stability compared to February harvest (conventional harvest), but nitrogen content in above ground crop was to high (208 kg ha.-1) to maintain sustainable crop production. Deionised water, 1.00% HCl and 0.10% Triton X-100 washes were used to reduce inorganic content of miscanthus. Miscanthus washed with 0.10% Triton X-100 resulted in the highest total liquid yield (76.21 wt. %) and lowest char and reaction water yields (9.77 wt. % and 8.25 wt. % respectively). Concentrations of Triton X-100 were varied to study further effects on mass balance yields and bio-oil stability. All concentrations of Triton X-100 increased total liquid yield and decreased char and reaction water yields compared to untreated miscanthus. In terms of bio-oil stability 1.00% Triton X-100 produced the most stable bio-oil with lowest viscosity index (2.43) and lowest water content index (1.01). Beech wood was impregnated with potassium and phosphorus resulting in lower liquid yields and increased char and gas yields due to their catalytic effect on fast pyrolysis product distribution. Increased potassium and phosphorus concentrations produced less stable bio-oils with viscosity and water content indexes increasing. Fast pyrolysis processing of phosphorus impregnated beech wood was problematic as the reactor bed material agglomerated into large clumps due to char formation within the reactor, affecting fluidisation and heat transfer.

Validity of a prototype surgical aberrometer

Poster Purpose: A study to validate a prototype Hartmann-Shack (HS) wavefront aberrometer. Methods: The dynamic range was assessed using a calibrated model eye. It was validated against a conventional HS-aberrometer (Topcon KR1W) in 75 eyes using both instruments in random order. Additionally, intra-sessional repeatability was tested. Results: The aberrometer showed a large dynamic range of +21.0 D to −25.0 D. It was comparable to a conventional HS aberrometer for spherical-equivalent SE (MD ± 95% CI: 0.02 ± 0.49D; correlation: r = 0.995, p < 0.001), astigmatic components (J0: 0.02 ± 0.15D; r = 0.977, p < 0.001; J45: 0.03 ± 0.28; r = 0.666, p < 0.001) and HOAs RMS (0.02 ± 0.20D; r = 0.620, p < 0.001). Intra-sessional repeatability correlation was also excellent (SE = 1.000, p < 0.001; astigmatic-components J0 = 0.998, p < 0.001, J45 = 0.980, p < 0.01; HOAs RMS = 0.961, p < 0.001). Conclusions: This study confirms the validity of the prototype aberrometer. The prototype aberrometer can measure continuously to provide direct feedback of the optical status of the eye during surgery.