Vertical Bone Augmentation Using Different Osteoconductive Scaffolds Combined with Barrier Domes in the Rat Calvarium

Purpose: To compare the regenerative potential for vertical bone augmentation of various osteoconductive scaffolds when used in conjunction with barrier domes. Materials and Methods: Following exposure and perforation of the calvarium, a gold occlusive dome was filled with the tested scaffold and anchored by fixation screws. Flaps were repositioned and secured. The four treatment groups, three to five rats each, were as follows: Bio‐Oss collagen (BOC), β‐tricalcium phosphate (TCP), collagen sponge (COL), and empty domes (C). Rats were sacrificed 8 weeks later, and specimens were prepared for histological and histomorphometric analysis. Vertical bone height and total tissue height were measured. Results: The newly regenerated bone appeared mature, highly vascularized, and with no signs of inflammation. Vertical bone height in the TCP group (mean 2.04 ± 0.2 mm) was greater than all other groups (0.76 ± 0.02, 1.52 ± 0.18, and 1.77 ± 0.61 mm for the BOC, C, and COL, respectively) but significantly only for the BOC group (p = .0145). Total tissue height was significantly higher (p < .0001) in both BOC and TCP groups (4.48 ± 0.23 and 5.5 ± 0.24 mm, respectively) compared with COL (3.22 ± 0.11 mm) and C (2.39 ± 0.3 mm) groups. Conclusion: TCP in conjunction with barrier dome resulted in greater vertical bone augmentation in the calvarium of rats.     

Multitasking: Effects of processing multiple auditory feature patterns

ERPs and behavioral responses were measured to assess how task‐irrelevant sounds interact with task processing demands and affect the ability to monitor and track multiple sound events. Participants listened to four‐tone sequential frequency patterns, and responded to frequency pattern deviants (reversals of the pattern). Irrelevant tone feature patterns (duration and intensity) and respective pattern deviants were presented together with frequency patterns and frequency pattern deviants in separate conditions. Responses to task‐relevant and task‐irrelevant feature pattern deviants were used to test processing demands for irrelevant sound input. Behavioral performance was significantly better when there were no distracting feature patterns. Errors primarily occurred in response to the to‐be‐ignored feature pattern deviants. Task‐irrelevant elicitation of ERP components was consistent with the error analysis, indicating a level of processing for the irrelevant features. Task‐relevant elicitation of ERP components was consistent with behavioral performance, demonstrating a “cost” of performance when there were two feature patterns presented simultaneously. These results provide evidence that the brain tracked the irrelevant duration and intensity feature patterns, affecting behavioral performance. Overall, our results demonstrate that irrelevant informational streams are processed at a cost, which may be considered a type of multitasking that is an ongoing, automatic processing of task‐irrelevant sensory events.     

Improving vision in adult amblyopia by perceptual learning

Practicing certain visual tasks leads, as a result of a process termed "perceptual learning," to a significant improvement in performance. Learning is specific for basic stimulus features such as local orientation, retinal location, and eye of presentation, suggesting modification of neuronal processes at the primary visual cortex in adults. It is not known, however, whether such low-level learning affects higher-level visual tasks such as recognition. By systematic low-level training of an adult visual system malfunctioning as a result of abnormal development (leading to amblyopia) of the primary visual cortex during the "critical period," we show here that induction of low-level changes might yield significant perceptual benefits that transfer to higher visual tasks. The training procedure resulted in a 2-fold improvement in contrast sensitivity and in letter-recognition tasks. These findings demonstrate that perceptual learning can improve basic representations within an adult visual system that did not develop during the critical period.     

New approach for pterygium removal using 20?% ethanol

The aim of this study is to present a new method for pterygium removal using ethanol 20?% solution, applied to a retrospective consecutive case series conducted in the Department of Ophthalmology, Soroka University Medical Center, Beer-Sheva, Israel. The technique adopted the following procedure. After subconjunctival bupivacaine hydrochloride 0.5?% injection, a metal ring well, as used in laser-assisted subepithelial keratectomy, was placed above the head of the pterygium. A few drops of ethanol 20?% were applied inside the well and maintained in place for 40?s. The ethanol was then washed with Balanced Salt Solution. Pterygium was easily separated starting at 2?mm central to the head using a spatula. The apex was excised with further separation of the fibrovascular tissue towards the base. The base was excised and mitomycin C 0.02?% applied for 2.5?min. The ocular surface was profusely washed leaving the bare sclera. Records were reviewed of all the patients who underwent pterygium removal with ethanol between May 2006 and March 2007. The results showed that 68 eyes from 64 patients were operated on. There were no intraoperative complications. During follow-up periods of at least 12?months, no serious side effects were detected and only two cases (2.9?%) of recurrence were observed. The results obtained show that the Pterygium removal using alcohol 20?% solution is a simple procedure, creates a clear separation plane between the pterygium and the underlying cornea, and is a safe procedure.     

Isolated foveal hypoplasia with secondary nystagmus and low vision is associated with a homozygous SLC38A8 mutation

Foveal hypoplasia, always accompanied by nystagmus, is found as part of the clinical spectrum of various eye disorders such as aniridia, albinism and achromatopsia. However, the molecular basis of isolated autosomal recessive foveal hypoplasia is yet unknown. Individuals of apparently unrelated non consanguineous Israeli families of Jewish Indian (Mumbai) ancestry presented with isolated foveal hypoplasia associated with congenital nystagmus and reduced visual acuity. Genome-wide homozygosity mapping followed by fine mapping defined a 830 Kb disease-associated locus (LOD score 3.5). Whole-exome sequencing identified a single missense mutation in the homozygosity region: c.95T>G, p.(Ile32Ser), in a conserved amino acid within the first predicted transmembrane domain of SLC38A8. The mutation fully segregated with the disease-associated phenotype, demonstrating an ∼10% carrier rate in Mumbai Jews. SLC38A8 encodes a putative sodium-dependent amino-acid/proton antiporter, which we showed to be expressed solely in the eye. Thus, a homozygous SLC38A8 mutation likely underlies isolated foveal hypoplasia.