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Papers by Christopher Noel

Research paper thumbnail of Comparison of Health State Utility Measures in Patients With Head and Neck Cancer

JAMA otolaryngology-- head & neck surgery, Jan 23, 2015

Accurate measurement of health state utilities (HU) is the cornerstone for cost-utility analyses ... more Accurate measurement of health state utilities (HU) is the cornerstone for cost-utility analyses and the valuation of quality of life for given health states. Current indirect methods of HU derivation lack face validity for patients with head and neck cancer. The appropriateness of these measures compared with direct methods, such as the standard gamble (SG), time trade-off (TTO), and visual analog scale (VAS), have not been assessed in this patient population. To assess the convergent and construct validities of 5 different HU derivation methods in patients with head and neck cancer. In a cross-sectional study, we recruited 100 consecutive patients with squamous cell carcinoma of the upper aerodigestive tract treated in the outpatient surgical oncology clinics of the Princess Margaret Cancer Centre from August 1 through October 31, 2014. We enrolled patients with a minimum of 3 months of follow-up after completion of treatment and no evidence of recurrent or metastatic disease. Par...

Research paper thumbnail of Extent of neck dissection following transoral robotic surgical resection of oropharyngeal squamous cell carcinoma: A report of a case and potential indications for inclusion of level i in a selective neck dissection

Head & neck, Jan 9, 2014

Background With new minimally invasive surgical techniques playing a role in the management of ea... more Background With new minimally invasive surgical techniques playing a role in the management of early oropharyngeal carcinomas, appropriate surgical management of the neck is an increasingly important consideration. Methods We present a case of a 47-year-old patient with a clinical T2N1M0 squamous cell carcinoma of the right tonsil with anterior extension towards the floor of mouth from the right glossotonsillar sulcus. Imaging revealed a solitary necrotic lymph node in IIA. The decision was made to proceed with a transoral robotic pharyngectomy and selective neck dissection (SND) of levels II-IV, followed by adjuvant radiotherapy. Results A post-operative scan revealed progressive regional disease in the anterior aspect of level IB, and, as such, a completion neck dissection of level I was performed. Conclusion Special consideration must be given to level I particularly in patients with glossotonsillar sulcus involvement and anterior extension towards the floor of mouth. This articl...

Research paper thumbnail of Visual Impairment and Unmet Eye Care Needs Among Homeless Adults in a Canadian City

JAMA Ophthalmology, 2015

IMPORTANCE The ocular status of homeless populations remains largely unknown. Given that visual a... more IMPORTANCE The ocular status of homeless populations remains largely unknown. Given that visual acuity has been shown to be heavily correlated with reduced well-being and decreased earning potential, findings of poor vision could have important health implications for people experiencing homelessness.

Research paper thumbnail of Excimer Ablation of Collagen-Based Corneal Substitutes

Purpose: Biosynthetic corneal hydrogels have already undergone successful implantation in human p... more Purpose: Biosynthetic corneal hydrogels have already undergone successful implantation in human patients with keratoconus and may one day serve as useful alternatives to human donor tissue for surgical and refractive procedures. For synthetic materials to be biocompatible, they should undergo laser ablation in a consistent and reproducible manner. The purpose of our study was 1) to determine the feasibility and consistency of excimer ablation of collagen-based corneal biomimics (hydrogels), 2) to compare the ablation rates of hydrogels with different mechanical properties. Methods: Twelve samples of four different hydrogel formulations (10% recombinant porcine collagen) underwent identical excimer ablations (125 µm PTK, 6.0 mm). All hydrogels were cross-linked using a carbodiimide (EDC), epoxy-based cross-linker (BDDGE) or combination (hybrid) to enhance their mechanical properties. Hydrogel ablations were captured using a specialized high resolution camera (optical profilometer). C...

Research paper thumbnail of Epoxy Cross-Linked Collagen and Collagen-Laminin Peptide Hydrogels as Corneal Substitutes

Journal of Functional Biomaterials, 2013

A bi-functional epoxy-based cross-linker, 1,4-Butanediol diglycidyl ether (BDDGE), was investigat... more A bi-functional epoxy-based cross-linker, 1,4-Butanediol diglycidyl ether (BDDGE), was investigated in the fabrication of collagen based corneal substitutes. Two synthetic strategies were explored in the preparation of the cross-linked collagen scaffolds. The lysine residues of Type 1 porcine collagen were directly cross-linked using OPEN ACCESS J. Funct. Biomater. 2013, 4 163

Research paper thumbnail of Correction: Koh, L.B., et al. Epoxy Cross-Linked Collagen and Collagen-Laminin Peptide Hydrogels as Corneal Substitutes. J. Funct. Biomater. 2013, 4, 162-177

Journal of Functional Biomaterials, 2014

Research paper thumbnail of Human serum albumin as protecting agent of silver nanoparticles: role of the protein conformation and amine groups in the nanoparticle stabilization

Journal of Nanoparticle Research, 2013

Thermally denatured human serum albumin interacts with *3.0 nm spherical AgNP enhancing the fluor... more Thermally denatured human serum albumin interacts with *3.0 nm spherical AgNP enhancing the fluorescence of Trp-214 at large protein/ nanoparticle ratios. However, using native HSA, no changes in the emission were observed. The observation is likely due to differences between native and denatured protein packing resulting from protein corona formation. We have also found that NH 2 blocking of the protein strongly affects the ability of the protein to protect AgNP from different salts/ions such as NaCl, PBS, Hank's buffer, Tris-HCl, MES, and DMEM. Additionally, AgNP can be readily prepared in aqueous solutions by a photochemical approach employing HSA as an in situ protecting agent. The role of the protein in this case is beyond that of protecting agent; thus, Ag ? ions and I-2959 complexation within the protein structure also affects the efficiency of AgNP formation. Blocking NH 2 in HSA modified the AgNP growth profile, surface plasmon band shape, and long-term stability suggesting that amine groups are directly involved in the formation and post-stabilization of AgNP. In particular, AgNP size and shape are extensively influenced by NH 2 blocking, leading primarily to cubes and plates with sizes around 5-15 nm; in contrast, spherical monodisperse 4.0 nm AgNP are observed for native HSA. The nanoparticles prepared by this protocol are non-toxic in primary cells and have remarkable antibacterial properties. Finally, surface plasmon excitation of native HSA@AgNP promoted loss of protein conformation in just 5 min, suggesting that plasmon heating causes protein denaturation using continuous light sources such as commercial LED.

Research paper thumbnail of Safety and Efficacy of Composite Collagen-Silver Nanoparticle Hydrogels as Tissue Engineering Scaffolds

Nanoscale, 2015

The increasing number of multidrug resistant bacteria has revitalized interest in seeking alterna... more The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering. The resulting hybrid materials at [AgNPs] < 0.4 μM retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 μM AgNPs in mice showed a reduction in the levels of IL-6 and other inflammation markers (CCL24, sTNFR-2, and TIMP1). Finally, an analysis of silver contents in implanted mice showed that silver accumulation primarily occurred within the tissue surrounding the implant.

articles by Christopher Noel

Research paper thumbnail of Extent of neck dissection after transoral robotic surgical resection of oropharyngeal squamous cell carcinoma: Report of a case and potential indications for inclusion of level I in a selective neck dissection

Research paper thumbnail of Type 1 Boston keratoprosthesis: outcomes at two Canadian centres

Research paper thumbnail of Unmet eye care needs among a homeless youth population

Research paper thumbnail of Motor and sensory morbidity associated with the anterolateral thigh perforator free flap

Research paper thumbnail of The fragility of statistically significant findings from randomized trials in head and neck surgery

Research paper thumbnail of Radiologic-Pathologic Correlation of Extranodal Extension in Patients With Squamous Cell Carcinoma of the Oral Cavity: Implications for Future Editions of the TNM Classification

Research paper thumbnail of Prevalence and impact of eye disease in an urban homeless and marginally housed population

Research paper thumbnail of Finding/identifying primaries with neck disease (FIND) clinical trial protocol: a study integrating transoral robotic surgery, histopathological localisation and tailored deintensification of radiotherapy for unknown primary and small oropharyngeal head and neck squamous cell carcinoma

Research paper thumbnail of Hearing loss and hearing needs in an adult homeless population: a prospective cross-sectional study

Research paper thumbnail of Feedback Frequency in Competence by Design: A Quality Improvement Initiative

Research paper thumbnail of Quality of life considerations for patients with anterior and central skull base malignancies

Research paper thumbnail of Blunt laryngeal trauma presenting as bilateral massive pneumothoraces and subcutaneous emphysema: a multidisciplinary approach to management

Research paper thumbnail of Comparison of Health State Utility Measures in Patients With Head and Neck Cancer

JAMA otolaryngology-- head & neck surgery, Jan 23, 2015

Accurate measurement of health state utilities (HU) is the cornerstone for cost-utility analyses ... more Accurate measurement of health state utilities (HU) is the cornerstone for cost-utility analyses and the valuation of quality of life for given health states. Current indirect methods of HU derivation lack face validity for patients with head and neck cancer. The appropriateness of these measures compared with direct methods, such as the standard gamble (SG), time trade-off (TTO), and visual analog scale (VAS), have not been assessed in this patient population. To assess the convergent and construct validities of 5 different HU derivation methods in patients with head and neck cancer. In a cross-sectional study, we recruited 100 consecutive patients with squamous cell carcinoma of the upper aerodigestive tract treated in the outpatient surgical oncology clinics of the Princess Margaret Cancer Centre from August 1 through October 31, 2014. We enrolled patients with a minimum of 3 months of follow-up after completion of treatment and no evidence of recurrent or metastatic disease. Par...

Research paper thumbnail of Extent of neck dissection following transoral robotic surgical resection of oropharyngeal squamous cell carcinoma: A report of a case and potential indications for inclusion of level i in a selective neck dissection

Head & neck, Jan 9, 2014

Background With new minimally invasive surgical techniques playing a role in the management of ea... more Background With new minimally invasive surgical techniques playing a role in the management of early oropharyngeal carcinomas, appropriate surgical management of the neck is an increasingly important consideration. Methods We present a case of a 47-year-old patient with a clinical T2N1M0 squamous cell carcinoma of the right tonsil with anterior extension towards the floor of mouth from the right glossotonsillar sulcus. Imaging revealed a solitary necrotic lymph node in IIA. The decision was made to proceed with a transoral robotic pharyngectomy and selective neck dissection (SND) of levels II-IV, followed by adjuvant radiotherapy. Results A post-operative scan revealed progressive regional disease in the anterior aspect of level IB, and, as such, a completion neck dissection of level I was performed. Conclusion Special consideration must be given to level I particularly in patients with glossotonsillar sulcus involvement and anterior extension towards the floor of mouth. This articl...

Research paper thumbnail of Visual Impairment and Unmet Eye Care Needs Among Homeless Adults in a Canadian City

JAMA Ophthalmology, 2015

IMPORTANCE The ocular status of homeless populations remains largely unknown. Given that visual a... more IMPORTANCE The ocular status of homeless populations remains largely unknown. Given that visual acuity has been shown to be heavily correlated with reduced well-being and decreased earning potential, findings of poor vision could have important health implications for people experiencing homelessness.

Research paper thumbnail of Excimer Ablation of Collagen-Based Corneal Substitutes

Purpose: Biosynthetic corneal hydrogels have already undergone successful implantation in human p... more Purpose: Biosynthetic corneal hydrogels have already undergone successful implantation in human patients with keratoconus and may one day serve as useful alternatives to human donor tissue for surgical and refractive procedures. For synthetic materials to be biocompatible, they should undergo laser ablation in a consistent and reproducible manner. The purpose of our study was 1) to determine the feasibility and consistency of excimer ablation of collagen-based corneal biomimics (hydrogels), 2) to compare the ablation rates of hydrogels with different mechanical properties. Methods: Twelve samples of four different hydrogel formulations (10% recombinant porcine collagen) underwent identical excimer ablations (125 µm PTK, 6.0 mm). All hydrogels were cross-linked using a carbodiimide (EDC), epoxy-based cross-linker (BDDGE) or combination (hybrid) to enhance their mechanical properties. Hydrogel ablations were captured using a specialized high resolution camera (optical profilometer). C...

Research paper thumbnail of Epoxy Cross-Linked Collagen and Collagen-Laminin Peptide Hydrogels as Corneal Substitutes

Journal of Functional Biomaterials, 2013

A bi-functional epoxy-based cross-linker, 1,4-Butanediol diglycidyl ether (BDDGE), was investigat... more A bi-functional epoxy-based cross-linker, 1,4-Butanediol diglycidyl ether (BDDGE), was investigated in the fabrication of collagen based corneal substitutes. Two synthetic strategies were explored in the preparation of the cross-linked collagen scaffolds. The lysine residues of Type 1 porcine collagen were directly cross-linked using OPEN ACCESS J. Funct. Biomater. 2013, 4 163

Research paper thumbnail of Correction: Koh, L.B., et al. Epoxy Cross-Linked Collagen and Collagen-Laminin Peptide Hydrogels as Corneal Substitutes. J. Funct. Biomater. 2013, 4, 162-177

Journal of Functional Biomaterials, 2014

Research paper thumbnail of Human serum albumin as protecting agent of silver nanoparticles: role of the protein conformation and amine groups in the nanoparticle stabilization

Journal of Nanoparticle Research, 2013

Thermally denatured human serum albumin interacts with *3.0 nm spherical AgNP enhancing the fluor... more Thermally denatured human serum albumin interacts with *3.0 nm spherical AgNP enhancing the fluorescence of Trp-214 at large protein/ nanoparticle ratios. However, using native HSA, no changes in the emission were observed. The observation is likely due to differences between native and denatured protein packing resulting from protein corona formation. We have also found that NH 2 blocking of the protein strongly affects the ability of the protein to protect AgNP from different salts/ions such as NaCl, PBS, Hank's buffer, Tris-HCl, MES, and DMEM. Additionally, AgNP can be readily prepared in aqueous solutions by a photochemical approach employing HSA as an in situ protecting agent. The role of the protein in this case is beyond that of protecting agent; thus, Ag ? ions and I-2959 complexation within the protein structure also affects the efficiency of AgNP formation. Blocking NH 2 in HSA modified the AgNP growth profile, surface plasmon band shape, and long-term stability suggesting that amine groups are directly involved in the formation and post-stabilization of AgNP. In particular, AgNP size and shape are extensively influenced by NH 2 blocking, leading primarily to cubes and plates with sizes around 5-15 nm; in contrast, spherical monodisperse 4.0 nm AgNP are observed for native HSA. The nanoparticles prepared by this protocol are non-toxic in primary cells and have remarkable antibacterial properties. Finally, surface plasmon excitation of native HSA@AgNP promoted loss of protein conformation in just 5 min, suggesting that plasmon heating causes protein denaturation using continuous light sources such as commercial LED.

Research paper thumbnail of Safety and Efficacy of Composite Collagen-Silver Nanoparticle Hydrogels as Tissue Engineering Scaffolds

Nanoscale, 2015

The increasing number of multidrug resistant bacteria has revitalized interest in seeking alterna... more The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering. The resulting hybrid materials at [AgNPs] < 0.4 μM retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 μM AgNPs in mice showed a reduction in the levels of IL-6 and other inflammation markers (CCL24, sTNFR-2, and TIMP1). Finally, an analysis of silver contents in implanted mice showed that silver accumulation primarily occurred within the tissue surrounding the implant.