Discovering Nature's Fingerprints: Isotope Ratio Analysis on Bioanalytical Mass Spectrometers.

For a generation or more, the mass spectrometry that developed at the frontier of molecular biology was worlds apart from isotope ratio mass spectrometry, a label-free approach done on optimized gas-source magnetic sector instruments. Recent studies show that electrospray-ionization Orbitraps and other mass spectrometers widely used in the life sciences can be fine-tuned for high-precision isotope ratio analysis. Since isotope patterns form everywhere in nature based on well-understood principles, intramolecular isotope measurements allow unique insights into a fascinating range of research topics.

Methods used by Canadian dairy farmers for on-farm euthanasia and the emotions associated with the decision and the practice of euthanasia.

On-farm euthanasia is complicated in that farmers have to make the decision to end the life of an animal they are caring for. Studies have shown that some culling decisions are made too late, which results in animal welfare issues. However, information about on-farm euthanasia methods and the decision process leading to the euthanasia of an animal is limited.

Considering social inequalities in health in large-scale testing for COVID-19 in Montréal: a qualitative case study.

Background: Evidence continues to demonstrate that certain marginalised populations are disproportionately affected by COVID-19. While many studies document the impacts of COVID-19 on social inequalities in health, none has examined how public health responses to the pandemic have unfolded to address these inequities in Canada. The purpose of our study was to assess how social inequalities in health were considered in the design and planning of large-scale COVID-19 testing programs in Montréal (Québec, Canada).

Recovery of Cranial Nerve Deficits in Patients Presenting with Pituitary Apoplexy: A Case Series.

 Pituitary apoplexy (PA) is a rare complication of pituitary tumors that can present with a myriad of symptoms, including sudden onset cranial nerve deficits. After patient stabilization and hormone replacement, surgical decompression is often recommended. The timing of surgical decompression remains controversial.

Clinical Outcomes of Endoscopic Endonasal Odontoidectomy: A Single-Center Experience.

Background: Odontoidectomy for basilar invagination and craniovertebral junction pathology traditionally has been performed using a transoral route. However, the endoscopic endonasal approach to the anterior craniovertebral junction may offer safer and more effective access when compared with transoral approaches. The objective of this study is to review the surgical outcomes and complications associated with endoscopic endonasal odontoidectomy.

Enhancing the Thermal Stability of Carbon Nanomaterials with DNA.

Single-walled carbon nanotubes (SWCNTs) have recently been utilized as fillers that reduce the flammability and enhance the strength and thermal conductivity of material composites. Enhancing the thermal stability of SWCNTs is crucial when these materials are applied to high temperature applications. In many instances, SWCNTs are applied to composites with surface coatings that are toxic to living organisms.

Planum-Clival Angle Classification: A Novel Preoperative Evaluation for Sellar/Parasellar Surgery.

Objective Endonasal approaches are increasingly used to treat sellar pathologies, leading to increased interest in achieving maximal safe resection. We propose a tool-the planum-clival angle (PCA)-and explore its surgical implications for sellar pathology resections. Design Retrospective analysis.

Interstitial brachytherapy in the management of persistent head and neck disease after definitive external beam radiation therapy.

Purpose: Persistent disease after definitive external beam radiation therapy for head and neck (H&N) malignancies negatively impacts survival. In this series, the effectiveness of low-dose-rate brachytherapy in the management of persistent H&N disease is explored.

Methods: All patients who received brachytherapy for persistent H&N disease between 1987 and 2002 were identified.

Brachytherapy in the retreatment of patients with new primary head and neck cancer.

Objective: Re-treatment for cure of the Head and Neck (H&N) region is therapeutically challenging. In this review we explore the long-term results of Ir(192) low-dose-rate (LDR) brachytherapy in the select subgroup of patients treated for a new H&N malignancy.

Methods & Material: Thirteen patients received brachytherapy between 1987-2004 for a new primary H&N cancer, six of whom had been retreated previously.

Interstitial low-dose-rate brachytherapy in the treatment of recurrent head and neck malignancies.

Background: Recurrent head and neck malignancies are therapeutically challenging. Brachytherapy is a retreatment alternative to external-beam radiation therapy (EBRT).

Methods: Patients receiving brachytherapy during 1987-2004 for recurrent head and neck cancer were identified.

A logical approach to the thoracic inlet: the Dartevelle approach revisited.

Background: Traditionally, Pancoast tumors have been associated with an extremely poor outlook. Recently, Dartevelle and colleagues have noted a significant survival advantage in patients treated by wide en bloc excision.

Methods: Utilizing an illustrative case example, step by step exposure of the lung apex and first rib is provided with the Dartevelle approach.

Recurrent thyroglossal duct cysts: a clinical and pathologic analysis.

Objective: To analyze, in detail, the clinical and pathological findings in a patient population that had undergone previous Sistrunk procedures for the removal of thyroglossal duct cysts, in order to identify any possible factors that could be related to recurrence after 'definitive' surgery.

Setting: A large pediatric tertiary care center.

Methods: A retrospective chart review was performed to include all patients treated at a single center for thyroglossal duct cysts with a Sistrunk procedure, between 1978 and 1992 inclusive.

Adult epiglottitis in a Canadian setting.

The objective of this study was to determine stable estimates of the incidence, case fatality, and epidemiologic features of adult epiglottitis, and risk factors for intubation. The authors designed a retrospective cohort combined with a nested case-control study, followed by detailed analysis of cases from two tertiary care institutions. Among 813 cases, the incidence was 2.

Description and evaluation of the vallecula sign: a new radiologic sign in the diagnosis of adult epiglottitis.

Study Objective: To describe and prospectively evaluate a new radiologic sign with the potential to increase the diagnostic accuracy of soft-tissue radiography of the neck in the identification of adult epiglottitis.

Methods: We conducted a prospective, before-and-after blinded study at two tertiary care institutions. A convenience sample of four staff emergency physicians, three otolaryngology residents, four radiology residents, and four senior medical students volunteered to participate.

A prospective comparison of octylcyanoacrylate tissue adhesive and suture for the closure of head and neck incisions.

Objective: To compare the tissue adhesive octylcyanoacrylate with subcuticular suture for the closure of head and neck incisions.

Design: A prospective comparison with a blinded assessment of cosmetic outcome.

Subjects: Fifty consecutive patients undergoing head and neck procedures at two University of Ottawa teaching hospitals.

Comparison of laser-assisted uvulopalatopharyngoplasty to electrocautery-assisted uvulopalatopharyngoplasty: a clinical and pathologic correlation in an animal model.

Objective: To determine if there are any pathologic or technical differences between laser-assisted uvulopalatopharyngoplasty (LAUP) and electrocautery-assisted uvulopalatopharyngoplasty (EAUP).

Design: A prospective randomized in vivo trial in an appropriate animal species.

Results: We found no gross difference in healing between the palates treated with laser and those treated with high-frequency electrocautery.

Factors affecting platinum concentrations in human surgical tumour specimens after cisplatin.

We assessed factors which affect cisplatin concentrations in human surgical tumour specimens. Cisplatin 10 mg m-2 was given i.v.

Cisplatin, cytosine arabinoside, and pentoxifylline in the treatment of squamous cell carcinoma of the head and neck.

Nine patients were entered on a Phase I-II study of cisplatin, cytosine arabinoside, and pentoxifylline in the treatment of advanced head and neck cancer. The treatment regimen consisted of cisplatin 100 mg/m2 intravenously on day 1 only, cytosine arabinoside 2,000 mg/m2 intravenously on days 1 and 2, and pentoxifylline 400 mg orally three times daily beginning 7 to 14 days before the chemotherapy. The pentoxifylline was continued between chemotherapy cycles.