Comparison of socio-economic determinants of COVID-19 testing and positivity in Canada:A multi-provincial analysis

BACKGROUND: The effects of the COVID-19 pandemic have been more pronounced for socially disadvantaged populations. We sought to determine how access to SARS-CoV-2 testing and the likelihood of testing positive for COVID-19 were associated with demographic factors, socioeconomic status (SES) and social determinants of health (SDH) in three Canadian provinces. METHODS: An observational population-based cross-sectional study was conducted for the provinces of Ontario, Manitoba and New Brunswick between March 1, 2020 and April 27, 2021, using provincial health administrative data. After excluding residents of long-term care homes, those without current provincial health insurance and those who were tested for COVID-19 out of province, records from provincial healthcare administrative databases were reviewed for 16,900,661 healthcare users. Data was modelled separately for each province in accordance to a prespecified protocol and follow-up consultations among provincial statisticians and collaborators. We employed univariate and multivariate regression models to examine determinants of testing and test results. RESULTS: After adjustment for other variables, female sex and urban residency were positively associated with testing, while female sex was negatively associated with test positivity. In New Brunswick and Ontario, individuals living in higher income areas were more likely to be tested, whereas in Manitoba higher income was negatively associated with both testing and positivity. High ethnocultural composition was associated with lower testing rates. Both high ethnocultural composition and high situational vulnerability increased the odds of testing positive for SARS-CoV-2. DISCUSSION: We observed that multiple demographic, income and SDH factors were associated with SARS-CoV-2 testing and test positivity. Barriers to healthcare access identified in this study specifically relate to COVID-19 testing but may reflect broader inequities for certain at-risk groups.</p

Molecular imaging of cell death in vivo by a novel small molecule probe

Apoptosis has a role in many medical disorders, therefore assessment of apoptosis in vivo can be highly useful for diagnosis, follow-up and evaluation of treatment efficacy. ApoSense is a novel technology, comprising low molecular-weight probes, specifically designed for imaging of cell death in vivo. In the current study we present targeting and imaging of cell death both in vitro and in vivo, utilizing NST-732, a member of the ApoSense family, comprising a fluorophore and a fluorine atom, for both fluorescent and future positron emission tomography (PET) studies using an 18F label, respectively. In vitro, NST-732 manifested selective and rapid accumulation within various cell types undergoing apoptosis. Its uptake was blocked by caspase inhibition, and occurred from the early stages of the apoptotic process, in parallel to binding of Annexin-V, caspase activation and alterations in mitochondrial membrane potential. In vivo, NST-732 manifested selective uptake into cells undergoing cell-death in several clinically-relevant models in rodents: (i) Cell-death induced in lymphoma by irradiation; (ii) Renal ischemia/reperfusion; (iii) Cerebral stroke. Uptake of NST-732 was well-correlated with histopathological assessment of cell-death. NST-732 therefore represents a novel class of small-molecule detectors of apoptosis, with potential useful applications in imaging of the cell death process both in vitro and in vivo

A Protocol for a Pan-Canadian Prospective Observational Study on Active Surveillance or Surgery for Very Low Risk Papillary Thyroid Cancer

BackgroundThe traditional management of papillary thyroid cancer (PTC) is thyroidectomy (total or partial removal of the thyroid). Active surveillance (AS) may be considered as an alternative option for small, low risk PTC. AS involves close follow-up (including regularly scheduled clinical and radiological assessments), with the intention of intervening with surgery for disease progression or patient preference.MethodsThis is a protocol for a prospective, observational, long-term follow-up multi-centre Canadian cohort study. Consenting eligible adults with small, low risk PTC (&lt; 2cm in maximal diameter, confined to the thyroid, and not immediately adjacent to critical structures in the neck) are offered the choice of AS or surgery for management of PTC. Patient participants are free to choose either option (AS or surgery) and the disease management course is thus not assigned by the investigators. Surgery is provided as usual care by a surgeon in an institution of the patient’s choice. Our primary objective is to determine the rate of ‘failure’ of disease management in respective AS and surgical arms as defined by: i) AS arm – surgery for progression of PTC, and ii) surgical arm - surgery or other treatment for disease persistence or progression after completing initial treatment. Secondary outcomes include long-term thyroid oncologic and treatment outcomes, as well as patient-reported outcomes.DiscussionThe results from this study will provide long-term clinical and patient reported outcome evidence regarding active surveillance or immediate surgery for management of small, low risk PTC. This will inform future clinical trials in disease management of small, low risk papillary thyroid cancer.Registration detailsThis prospective observational cohort study is registered on clinicaltrials.gov (NCT04624477), but it should not be considered a clinical trial as there is no assigned intervention and patients are free to choose either AS or surgery

Sentinel Lymph Node Biopsy in Head and Neck Melanoma: A Review

The incidence of melanoma in the United States continues to rise. Head and neck melanomas comprise approximately 20% of all primary cutaneous melanomas. Sentinel lymph node (SLN) biopsy (SLNB) has become the standard of care for staging in melanoma. It has a number of advantages, including the addition of prognostic information, accurate staging, and the potential to add completion lymph node dissection (CLND) or adjuvant therapy when indicated. Furthermore, it may allow for the identification of patients who would benefit from inclusion in clinical trials; this advantage may be amplified based on the introduction of novel targeted therapies. SLNB does have some disadvantages in head and neck melanomas. The complex lymphatic drainage and anatomy of the head and neck can result in some technical challenges. SLN positivity rates in head and neck melanoma are lower than for trunk or extremity melanoma; despite this, overall and disease free survival rates are lower in head and neck melanoma. This review examines the literature evidence for the efficacy of SLNB in head and neck melanoma, and in particular attempts to estimate five variables: the likelihood of finding a SLN, the number of SLNs found, the likelihood of a positive SLN, the likelihood of identifying positive non-sentinel lymph nodes on CLND, and the likelihood of recurrence in the neck despite a negative SLNB. Overall, despite the technical challenges inherent in SLNB when applied to head and neck melanoma, it remains a technically feasible and effective procedure in this anatomic site

Sentinel Lymph Node Biopsy in Head and Neck Melanoma: A Review

The incidence of melanoma in the United States continues to rise. Head and neck melanomas comprise approximately 20% of all primary cutaneous melanomas. Sentinel lymph node (SLN) biopsy (SLNB) has become the standard of care for staging in melanoma. It has a number of advantages, including the addition of prognostic information, accurate staging, and the potential to add completion lymph node dissection (CLND) or adjuvant therapy when indicated. Furthermore, it may allow for the identification of patients who would benefit from inclusion in clinical trials; this advantage may be amplified based on the introduction of novel targeted therapies. SLNB does have some disadvantages in head and neck melanomas. The complex lymphatic drainage and anatomy of the head and neck can result in some technical challenges. SLN positivity rates in head and neck melanoma are lower than for trunk or extremity melanoma; despite this, overall and disease free survival rates are lower in head and neck melanoma. This review examines the literature evidence for the efficacy of SLNB in head and neck melanoma, and in particular attempts to estimate five variables: the likelihood of finding a SLN, the number of SLNs found, the likelihood of a positive SLN, the likelihood of identifying positive non-sentinel lymph nodes on CLND, and the likelihood of recurrence in the neck despite a negative SLNB. Overall, despite the technical challenges inherent in SLNB when applied to head and neck melanoma, it remains a technically feasible and effective procedure in this anatomic site

Sentinel Lymph Node Biopsy in Head and Neck Melanoma: A Review

The incidence of melanoma in the United States continues to rise. Head and neck melanomas comprise approximately 20% of all primary cutaneous melanomas. Sentinel lymph node (SLN) biopsy (SLNB) has become the standard of care for staging in melanoma. It has a number of advantages, including the addition of prognostic information, accurate staging, and the potential to add completion lymph node dissection (CLND) or adjuvant therapy when indicated. Furthermore, it may allow for the identification of patients who would benefit from inclusion in clinical trials; this advantage may be amplified based on the introduction of novel targeted therapies. SLNB does have some disadvantages in head and neck melanomas. The complex lymphatic drainage and anatomy of the head and neck can result in some technical challenges. SLN positivity rates in head and neck melanoma are lower than for trunk or extremity melanoma; despite this, overall and disease free survival rates are lower in head and neck melanoma. This review examines the literature evidence for the efficacy of SLNB in head and neck melanoma, and in particular attempts to estimate five variables: the likelihood of finding a SLN, the number of SLNs found, the likelihood of a positive SLN, the likelihood of identifying positive non-sentinel lymph nodes on CLND, and the likelihood of recurrence in the neck despite a negative SLNB. Overall, despite the technical challenges inherent in SLNB when applied to head and neck melanoma, it remains a technically feasible and effective procedure in this anatomic site

Reconstruction following EEA: a 0.5% CSF leak rate in 200 consecutive cases

INTRODUCTION: Reconstruction of the ventral skull base after the Expanded Endonasal Approach (EEA) remains a controversial issue. The development of the pedicled nasoseptal flap (NSF) has been a seminal event in the maturation of EEA, resulting in a marked reduction in cerebrospinal fluid (CSF) leak rates after the procedure. However, other reconstructive options exist, including the use of non-vascularized tissue such as autografts of fat or fascia lata, homografts and tissue adhesives. In addition, many centers now use a hybrid approach, reserving the use of the NSF for high risk cases, and using non-vascularized reconstructions for low risk situations or when the NSF is unavailable because of previous resections or tumor involvement. Our group has routinely used the NSF when available for all EEA cases, with resections of the nasopharynx and drainage of skull base infections and cholesterol granulomas being the most notable exceptions. In addition, we have used other vascularized reconstructions (including the lateral vault flap and, in one case, free tissue transfer) in situations where the NSF is unavailable. This paper will report on our protocol for ventral skull base reconstruction after EEA and examine our CSF leak rate over our last 200 consecutive cases. METHODS: Retrospective chart review of 200 EEA cases performed at two institutions by a single surgical team. The variables measured were method of reconstruction, pathology, and incidence of CSF leak. RESULTS: A total of 200 cases were performed by this single surgical team. There was one episode of CSF leak in these 200 consecutive cases (0.5%). DISCUSSION: Although there are numerous centers using non-vascularized reconstruction of the ventral skull base after in a significant proportion of cases, our protocol has been to use vascularized reconstruction as a routine in all but very selected cases. This has resulted in an extremely low rate of CSF leak