Rising to the Challenge of Rare Diagnoses.

Patients with rare conditions often experience substantial delays between presentation and diagnosis, and some remain undiagnosed. In this Perspective, we outline the many challenges in diagnosing rare conditions in the modern clinical context. We review relevant concepts of diagnostic reasoning as they relate to rare conditions.

Prone positioning of patients with moderate hypoxaemia due to covid-19: multicentre pragmatic randomised trial (COVID-PRONE).

Objectives: To assess the effectiveness of prone positioning to reduce the risk of death or respiratory failure in non-critically ill patients admitted to hospital with covid-19.

Design: Multicentre pragmatic randomised clinical trial.

Setting: 15 hospitals in Canada and the United States from May 2020 until May 2021.

Does maternal HSV-2 coinfection increase mother-to-child transmission of HIV? A systematic review.

Background: Reducing HIV mother-to-child transmission (MTCT) is critical to ending the HIV pandemic. Reports suggest that herpes simplex virus-2 (HSV-2), a common coinfection in HIV-infected individuals, is associated with increased MTCT, but results have been conflicting. We conducted a systematic review of observational studies to quantify the magnitude of this relationship (PROSPERO no.

Percutaneous Coronary Intervention in a Patient With Severe Systemic Vasculitis and Myocardial Infarction.

A 72-year-old woman presented with acute coronary syndrome. There was diffuse coronary ectasia and severe stenosis in the proximal left anterior descending artery consistent with coronary vasculitis. Despite treatment with high-dose immunosuppression, she underwent percutaneous coronary intervention for refractory angina.