Endoscopic Corneal Neurotization: Cadaver Feasibility Study.

PURPOSE: The authors describe a cadaver feasibility study investigating a minimally invasive technique for corneal neurotization with the supraorbital nerve harvested endoscopically. METHODS: A cadaver study was performed to investigate the technical feasibility of corneal neurotization via endoscopic supraorbital nerve transfer to the corneoscleral limbus. RESULTS: Endoscopic corneal neurotization was successfully performed on each cadaveric hemiface. CONCLUSION: The use of an endoscope allows for a minimally invasive approach to corneal neurotization with the supraorbital nerve.

Enteral nutrition support in burn care: a review of current recommendations as instituted in the Ross Tilley Burn Centre.

Failure to adequately address the increased levels of inflammatory mediators, catecholamines and corticosteroids central to the hypermetabolic response post burn injury can lead to catastrophic results. One of the most important perturbations is provision of adequate and early nutrition. The provision of the right balance of macro and micronutrients, along with additional antioxidants is essential to mitigating the hypermetabolic and hypercatabolic state that results following a burn injury. As it is now widely accepted that enteral feeding is best practice for the burn population research has been more closely examining the individual components of enteral nutrition support. Recently fat to carbohydrate ratios, glutamine and antioxidants have made up the balance of this focus. This paper provides a review of the most recent literature examining each of these components and discusses the practices adopted in the Ross Tilley Burn Centre at Sunnybrook Health Sciences Centre.

Dietary vitamin D intake among elderly residents in a Veterans' Centre.

PURPOSE: Dietary vitamin D intake was assessed among residents in a long-term care (LTC) facility, so that recommendations could be made about vitamin D supplementation. METHODS: Three-day tray audits were completed for all meals and snacks, including nutritional supplements (Boost and/or high-protein pudding). Total daily and three-day vitamin D intake was calculated for each resident, and the total sample was compared with the recommended Adequate Intake (AI) of 600 IU. Vitamin D content was calculated using the Canadian Nutrient File and product labels. Resident charts were reviewed for micronutrient supplements and diagnoses. RESULTS: The daily average vitamin D available to and consumed by 30 residents was 414 IU and 295 IU, respectively. Those provided with nutritional supplements received an average of 480 IU and consumed 357 IU, while those without received an average of 245 IU and consumed 207 IU. Thirty-three percent of residents were diagnosed with osteoporosis, osteoarthritis, and falls and/or fractures. Vitamin D micronutrient supplementation varied from above 600 IU (43%) to below 600 IU (30%) to no supplementation (27%). CONCLUSIONS: None of the study participants met the recommended AI of 600 IU through dietary sources alone. Study results suggest that all LTC residents require vitamin D micronutrient supplementation of at least 400 IU to achieve the recommended AI of 600 IU.

Optimization of ribonucleic acid detection from archival Guinea pig temporal bone specimens.

HYPOTHESIS: The choice of ribonucleic acid (RNA) isolation protocol coupled with modifications to RNA extraction and detection procedures may result in a more reliable method to detect gene expression in archived temporal bones. BACKGROUND: A large number of archival temporal bones exist. Retrospective analysis of these specimens using techniques of RNA extraction will greatly enrich our understanding of the pathophysiology of specific otologic diseases. However, archival human temporal bones are aged and embedded in paraffin or celloidin, rendering isolation and manipulation of nucleic acid in preserved specimens difficult, especially as it pertains to RNA degradation. Despite some reports of moderate success in the recent past, RNA isolation and gene expression using polymerase chain reaction (PCR) analysis continues to be challenging and unreliable. Archival guinea pig temporal bone specimens were used to develop and optimize a protocol for RNA extraction and gene expression analysis using PCR and quantitative PCR methods. The genes amplified comprise housekeeping genes and genes associated with the glutamate pathway. METHODS: Archival celloidin-embedded guinea pig temporal bones were collected from the senior author's collection of experimental hydropic inner ear specimens. RNA from this tissue was extracted using the protocol described previously in 16animals and using a modified trizol extraction technique in 10 animals. Gene expression analysis was performed on the extracted RNA. Analysis included two housekeeping genes, GAPDH and 18S, as well as three mediators of the glutamate pathway, glutamate aspartate transporter, glutamate synthetase, and inducible nitric oxide synthase. RESULTS: Compared with the standard extraction protocol, the trizol-based extraction technique showed greater reliability and reproducibility of RNA detection. The housekeeping gene GAPDH or 18S was detected in 7 of 36 attempts with the standard protocol versus 9 of 9 using the modified extraction method (P < 0.001). The gene of interest, glutamate aspartate transporter, was detected in 3 of 26 attempts with the standard protocol versus 12 of 13 attempts using the modified extraction method (P < 0.001). Quantification of messenger RNA levels was then achieved using quantitative PCR methods. CONCLUSION: Improved reliability for detection of gene expression and demonstration of reproducibility were accomplished by modification of RNA extraction technique and standard reverse transcriptase PCR protocol. In addition, we also showed that gene expression from archival material can be quantified by real-time PCR.