The role of urate and xanthine oxidase in vascular oxidative stress:Future directions

Vascular oxidative stress has been shown to be a potent factor in the pathophysiology of endothelial dysfunction. Despite current optimal evidence-based therapy, mortality from various cardiovascular disorders remains high. The search for newer, novel ways of attenuating endothelial dysfunction has yielded several new and exciting possibilities, one of which is the manipulation of urate levels using xanthine oxidase inhibitors. Agents such as allopurinol have shown marked improvements in vascular endothelial function in various cohorts at risk of cardiovascular events. Most of the evidence so far comes from smaller mechanistic studies. The few large randomized controlled trials have failed to show any significant mortality benefit using these agents. This article highlights the potential avenues of further research such as dose-response, and the potential for these agents to regress left ventricular hypertrophy. The role of newer agents such as febuxostat and oxypurinol are discussed as well as potential reasons why some of the current newer agents have failed to live up to the promising early-phase data. It is crucial that these remaining questions surrounding urate, xanthine oxidase and the role of various agents that affect this important oxidative stress-generating system are answered, and therefore these promising agents should not be discarded prematurely

Role of urate, xanthine oxidase and the effects of allopurinol in vascular oxidative stress

Oxidative stress plays an important role in the progression of vascular endothelial dysfunction. The two major systems generating vascular oxidative stress are the NADPH oxidase and the xanthine oxidase pathways. Allopurinol, a xanthine oxidase inhibitor, has been in clinical use for over 40 years in the treatment of chronic gout. Allopurinol has also been shown to improve endothelial dysfunction, reduce oxidative stress burden and improve myocardial efficiency by reducing oxygen consumption in smaller mechanistic studies involving various cohorts at risk of cardiovascular events. This article aims to explain the role of xanthine oxidase in vascular oxidative stress and to explore the mechanisms by which allopurinol is thought to improve vascular and myocardial indices

Compact Microring-Based Wavelength-Selective Inline Optical Reflector

We present a novel design for a compact planar integrated optic reflector based on a microring resonator add–drop wavelength-selective filter. Good agreement is found between the theoretical expectation and the measurements of a device fabricated in optical polymer. The measured device exhibits better than 10-dB rejection for wavelengths resonant with the microring

The Distribution of Earnings Profiles in Longitudinal Data

We take advantage of our longitudinal data to explore individual variation in the parameters of individual earnings functions. (1) For this purpose we fit an earnings function to each of the individual histories in the sample.(2) We then try to ascertain the extent to which the estimated variation in individual parameters helps in explaining the cross-sectional variation in earnings.(3) we further inquire into the relation between the individual parameters and a vector of personal characteristics, as well as(4) into indirect (via variables and parameters) and direct effects of these characteristics on earnings.

All optically tunable wavelength-selective reflector consisting of coupled polymeric microring resonators

We present an all optically tunable wavelength-selective reflector for planar lightwave technology based on coupled microring resonators. By employing the Vernier effect, we demonstrate narrow-band reflection and strong side-lobe suppression in an optical polymer device fabricated by soft lithography. Wide and simple tuning of the reflection peak using an external control beam is demonstrated

Transient Hydroureteronephrosis Caused by a Foley's Catheter Tip in the Right Ureter

We report a case of unilateral hydronephrosis following urethral catheterization in a patient with T6 complete paraplegia at the Physical Medicine and Rehabilitation Department in a tertiary care teaching hospital, India. Diagnosis was established by an abdominal ultrasound. The misplaced catheter tip was withdrawn from the ureteric orifice and hydronephrosis was resolved. Foley's catheterization, a widely practiced clinical procedure, is not without its attendant risks of an inadvertent placement in the ureter leading to transient hydronephrosis. Inadequate drainage through a catheter should thus alert one to this potentially hazardous complication that can be diagnosed by an early ultrasound. This complication can be avoided by gently tugging on the catheter after inflating the catheter bulb