Electron spin resonance assay of ascorbyl radical generation in mouse hippocampal slices during and after kainate-induced seizures

As an index of oxidative status, we analyzed ascorbyl radical generation during and after kainate-induced seizures in mouse hippocampus, using an ESR spectrometer equipped with a special tissue-type quartz cell. A specific doublet ESR spectrum was observed after seizures, and the g value and the hyperfine coupling constant (hfcc) of the spectrum were identical with those of ascorbyl radical itself. Antiepileptic zonisamide inhibited the generation of ascorbyl radical accompanying the seizures.     

New insights into childhood ependymomas

Childhood ependymomas, which comprise approximately 10% to 15% of all brain tumors arising in patients less than 18 years of age, remain a highly problematic group of tumors to treat. Relapse-free survival rates vary significantly in contemporary series, and therapeutic approaches remain unsettled.     

Cerebrovascular abnormalities in a population of children with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is associated with vasculopathy, which may result in a variety of cerebrovascular complications. The purpose of this study was to evaluate the spectrum of cerebrovascular disease in a pediatric population with NF1. Of 316 patients with NF1 who underwent brain MRI, 8 (2.5%) children were reported to have an abnormality of the cerebrovascular system, including narrowed or ectatic vessels, vascular stenoses, aneurysm, and moyamoya.     

Power modulations in new phacoemulsification technology: improved outcomes

PURPOSE: To evaluate the clinical outcomes of new phacoemulsification technology. SETTING: Oregon Eye Institute, Eugene, Oregon, USA. METHODS: After optimization of surgical parameters, patients were randomly assigned to cataract extraction with 1 of 4 phacoemulsification machines using new technology available within the past 1 to 2 years. Outcomes were compared with previously published results for these same machines obtained before the advent of the new technology. RESULTS: Improvements in effective phaco time, average phaco power, percentage of clear corneas, and 20/40 or better uncorrected visual acuity at the first postoperative visit were noted for most systems using new technology. CONCLUSION: New phacoemulsification technology offers surgical advantages that translate into improved clinical outcomes.     

Wavefront technology in cataract surgery

PURPOSE OF REVIEW: As advances in technology allow cataract surgeons to address higher order optical aberrations, the measurement of functional vision becomes increasingly critical. Contrast sensitivity testing is assuming a prominent place in our evaluation of surgical modalities because it reflects functional vision and correlates with visual performance. The Tecnis Z9000 intraocular lens (IOL) (Pfizer, New York) is the first foldable IOL designed to correct higher order optical aberrations and represents a first step toward the integration of wavefront technology and cataract surgery. RECENT FINDINGS: Contrast sensitivity declines with age, even in the absence of ocular pathology. Wavefront science demonstrates that the youthful crystalline lens compensates for aberrations in the cornea. The aging lens loses its balance with the cornea, as both the magnitude and the sign of its spherical aberration change. Older pseudophakic patients have generally the same contrast sensitivity as their age-matched counterparts without cataract. The Tecnis Z9000 IOL (Pfizer, New York) has been designed with a modified prolate anterior surface to compensate for the spherical aberration of the cornea, thus eliminating total ocular spherical aberration. Clinical data demonstrate that this modified prolate IOL provides superior functional vision, similar to that of younger people, and hence improves visual performance when compared with conventional spherical IOLs. It appears likely that the decline in functional vision with age involves changes in the spherical aberration of the crystalline lens. SUMMARY: The integration of wave-front technology and lens-based surgery represents a step toward improving functional vision and quality of life for cataract patients.