Changes in monkey crystalline lens spherical aberration during simulated accommodation in a lens stretcher

8 págs.; 7 figs.; 2 apps.© 2015 The Association for Research in Vision and Ophthalmology, Inc. PURPOSE. The purpose of this study was to quantify accommodation-induced changes in the spherical aberration of cynomolgus monkey lenses. METHODS. Twenty-four lenses from 20 cynomolgus monkeys (Macaca fascicularis; 4.4-16.0 years of age; postmortem time 13.5±13.0 hours) were mounted in a lens stretcher. Lens spherical aberration was measured in the unstretched (accommodated) and stretched (relaxed) states with a laser ray tracing system that delivered 51 equally spaced parallel rays along 1 meridian of the lens over the central 6-mm optical zone. A camera mounted below the lens was used to measure the ray height at multiple positions along the optical axis. For each entrance ray, the change in ray height with axial position was fitted with a third-order polynomial. The effective paraxial focal length and Zernike spherical aberration coefficients corresponding to a 6-mm pupil diameter were extracted from the fitted values. RESULTS. The unstretched lens power decreased with age from 59.3±6 4.0 diopters (D) for young lenses to 45.7±6 3.1 D for older lenses. The unstretched lens shifted toward less negative spherical aberration with age, from -6.3±0.7 lm for young lenses to-5.0±0.5 lm for older lenses. The power and spherical aberration of lenses in the stretched state were independent of age, with values of 33.5±6 3.4 D and-2.6±0.5 lm, respectively. CONCLUSIONS. Spherical aberration is negative in cynomolgus monkey lenses and becomes more negative with accommodation. These results are in good agreement with the predicted values using computational ray tracing in a lens model with a reconstructed gradient refractive index. The spherical aberration of the unstretched lens becomes less negative with age.Supported by National Institutes of Health Grants R01EY14225, R01EY021834, and F31EY021444 Ruth L. Kirschstein National Research Service Award individual predoctoral fellowship [BM]), and center Grant P30EY14801; Australian government Cooperative Research Centre Scheme (Vision CRC); Florida Lions Eye Bank; Karl R. Olsen and Martha E. Hildebrandt; an unrestricted grant from Research to Prevent Blindness; Henri and Flore Lesieur Foundation (JMP); Spanish government Grant FIS2011-25637; and European Research Council Grants ERC-2011-AdG-294099 and CSIC i-LINKþ0609Peer Reviewe

Identifying factors associated with sedentary time after stroke. Secondary analysis of pooled data from nine primary studies.

<p><b>Background</b>: High levels of sedentary time increases the risk of cardiovascular disease, including recurrent stroke.</p> <p><b>Objective</b>: This study aimed to identify factors associated with high sedentary time in community-dwelling people with stroke.</p> <p><b>Methods</b>: For this data pooling study, authors of published and ongoing trials that collected sedentary time data, using the activPAL monitor, in community-dwelling people with stroke were invited to contribute their raw data. The data was reprocessed, algorithms were created to identify sleep-wake time and determine the percentage of waking hours spent sedentary. We explored demographic and stroke-related factors associated with total sedentary time and time in uninterrupted sedentary bouts using unique, both univariable and multivariable, regression analyses.</p> <p><b>Results</b>: The 274 included participants were from Australia, Canada, and the United Kingdom, and spent, on average, 69% (SD 12.4) of their waking hours sedentary. Of the demographic and stroke-related factors, slower walking speeds were significantly and independently associated with a higher percentage of waking hours spent sedentary (p = 0.001) and uninterrupted sedentary bouts of <i>>30</i> and <i>>60 min</i> (p = 0.001 and p = 0.004, respectively). Regression models explained 11–19% of the variance in total sedentary time and time in prolonged sedentary bouts.</p> <p><b>Conclusion</b>: We found that variability in sedentary time of people with stroke was largely unaccounted for by demographic and stroke-related variables. Behavioral and environmental factors are likely to play an important role in sedentary behavior after stroke. Further work is required to develop and test effective interventions to address sedentary behavior after stroke.</p

Combined anterior segment OCT and wavefront-based autorefractor using a shared beam

We have combined an anterior segment (AS) optical coherence tomography (OCT) system and a wavefront-based aberrometer with an approach that senses ocular wavefront aberrations using the OCT beam. Temporal interlacing of the OCT and aberrometer channels allows for OCT images and refractive error measurements to be acquired continuously and in real-time. The system measures refractive error with accuracy and precision comparable to that of clinical autorefractors. The proposed approach provides a compact modular design that is suitable for integrating OCT and wavefront-based autorefraction within the optical head of the ophthalmic surgical microscope for guiding cataract surgery or table-top devices for simultaneous autorefraction and ocular biometry

A Novel Unsupervised Method to Identify Genes Important in the Anti-viral Response: Application to Interferon/Ribavirin in Hepatitis C Patients

Background: Treating hepatitis C with interferon/ribavirin results in a varied response in terms of decrease in viral titer and ultimate outcome. Marked responders have a sharp decline in viral titer within a few days of treatment initiation, whereas in other patients there is no effect on the virus (poor responders). Previous studies have shown that combination therapy modifies expression of hundreds of genes in vitro and in vivo. However, identifying which, if any, of these genes have a role in viral clearance remains challenging. Aims: The goal of this paper is to link viral levels with gene expression and thereby identify genes that may be responsible for early decrease in viral titer. Methods: Microarrays were performed on RNA isolated from PBMC of patients undergoing interferon/ribavirin therapy. Samples were collected at pre-treatment (day 0), and 1, 2, 7, 14 and 28 days after initiating treatment. A novel method was applied to identify genes that are linked to a decrease in viral titer during interferon/ribavirin treatment. The method uses the relationship between inter-patient gene expression based proximities and inter-patient viral titer based proximities to define the association between microarray gene expression measurements of each gene and viral-titer measurements. Results: We detected 36 unique genes whose expressions provide a clustering of patients that resembles viral titer based clustering of patients. These genes include IRF7, MX1, OASL and OAS2, viperin and many ISG's of unknown function. Conclusion: The genes identified by this method appear to play a major role in the reduction of hepatitis C virus during the early phase of treatment. The method has broad utility and can be used to analyze response to any group of factors influencing biological outcome such as antiviral drugs or anti-cancer agents where microarray data are available. © 2007 Brodsky et al

Оценка воздействия дамбы в д. Босоногово Бердюжского района на окружающую среду Тюменской области

В статье рассмотрена положительная и отрицательная оценка воздействия дамбы в д. Босоногово Бердюжского района на окружающую среду Тюменской области.The article considers a positive and negative assessment of the impact of a dam in the village of Bosonogovo, Berdyuga district, on the environment of the Tyumen region

Hyperferritinemia and hypergammaglobulinemia predict the treatment response to standard therapy in autoimmune hepatitis.

Autoimmune hepatitis (AIH) is a chronic hepatitis with an increasing incidence. The majority of patients require life-long immunosuppression and incomplete treatment response is associated with a disease progression. An abnormal iron homeostasis or hyperferritinemia is associated with worse outcome in other chronic liver diseases and after liver transplantation. We assessed the capacity of baseline parameters including the iron status to predict the treatment response upon standard therapy in 109 patients with untreated AIH type 1 (AIH-1) in a retrospective single center study. Thereby, a hyperferritinemia (> 2.09 times upper limit of normal; Odds ratio (OR) = 8.82; 95% confidence interval (CI): 2.25-34.52) and lower immunoglobulins (<1.89 times upper limit of normal; OR = 6.78; CI: 1.87-24.59) at baseline were independently associated with the achievement of complete biochemical remission upon standard therapy. The predictive value increased when both variables were combined to a single treatment response score, when the cohort was randomly split into a training (area under the curve (AUC) = 0.749; CI 0.635-0.863) and internal validation cohort (AUC = 0.741; CI 0.558-0.924). Patients with a low treatment response score (<1) had significantly higher cumulative remission rates in the training (p<0.001) and the validation cohort (p = 0.024). The baseline hyperferritinemia was accompanied by a high serum iron, elevated transferrin saturations and mild hepatic iron depositions in the majority of patients. However, the abnormal iron status was quickly reversible under therapy. Mechanistically, the iron parameters were not stringently related to a hepatocellular damage. Ferritin rather seems deregulated from the master regulator hepcidin, which was down regulated, potentially mediated by the elevated hepatocyte growth factor. In conclusion, baseline levels of serum ferritin and immunoglobulins, which are part of the diagnostic work-up of AIH, can be used to predict the treatment response upon standard therapy in AIH-1, although confirmation from larger multicenter studies is pending

A more active lifestyle in persons with a recent spinal cord injury benefits physical fitness and health

Study design:A prospective cohort study. Objectives:To study the longitudinal relationship between objectively measured everyday physical activity level, and physical fitness and lipid profile in persons with a recent spinal cord injury (SCI).Setting:A rehabilitation centre in the Netherlands and the participant's home environment. Methods:Data of 30 persons with a recent SCI were collected at the start of active rehabilitation, 3 months later, at discharge from inpatient rehabilitation, and 1 year after discharge. Physical activity level (duration of dynamic activities as % of 24 h) was measured with an accelerometry-based activity monitor. Regarding physical fitness, peak oxygen uptake (VO2peak) and peak power output (POpeak) were determined with a maximal wheelchair exercise test, and upper extremity muscle strength was measured with a handheld dynamometer. Fasting blood samples were taken to determine the lipid profile. Results:An increase in physical activity level was significantly related to an increase in VO2peak and POpeak, and an increase in physical activity level favourably affected the lipid profile. A nonsignificant relation was found with muscle strength. Conclusion:Everyday physical activity seems to have an important role in the fitness and health of persons with a recent SCI. An increase in physical activity level was associated with an increase in physical fitness and with a lower risk of cardiovascular disease.Spinal Cord advance online publication, 6 December 2011; doi:10.1038/sc.2011.152

Plasma bile acids are not associated with energy metabolism in humans

Bile acids (BA) have recently been shown to increase energy expenditure in mice, but this concept has not been tested in humans. Therefore, we investigated the relationship between plasma BA levels and energy expenditure in humans. Type 2 diabetic (T2DM) patients (n = 12) and gender, age and BMI-matched healthy controls (n = 12) were studied before and after 8 weeks of treatment with a BA sequestrant. In addition, patients with liver cirrhosis (n = 46) were investigated, since these display elevated plasma BA together with increased energy expenditure. This group was compared to gender-, age- and BMI-matched healthy controls (n = 20). Fasting plasma levels of total BA and individual BA species as well as resting energy expenditure were determined. In response to treatment with the BA sequestrant, plasma deoxycholic acid (DCA) levels decreased in controls (-60%, p &lt;0.05) and T2DM (-32%, p &lt;0.05), while chenodeoxycholic acid (CDCA) decreased in controls only (-33%, p &lt;0.05). Energy expenditure did not differ between T2DM and controls at baseline and, in contrast to plasma BA levels, was unaffected by treatment with the BA sequestrant. Total BA as well as individual BA species did not correlate with energy expenditure at any time throughout the study. Patients with cirrhosis displayed on average an increase in energy expenditure of 18% compared to values predicted by the Harris-Benedict equation, and plasma levels of total BA (up to 12-fold) and individual BA (up to 20-fold) were increased over a wide range. However, neither total nor individual plasma BA levels correlated with energy expenditure. In addition, energy expenditure was identical in patients with a cholestatic versus a non-cholestatic origin of liver disease while plasma total BA levels differed four-fold between the groups. In conclusion, in the various (patho) physiological conditions studied, plasma BA levels were not associated with changes in energy expenditure. Therefore, our data do not support an important role of circulating BA in the control of human energy metabolism.</p