Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Cardiovocal syndrome due to a dilated pulmonary artery

Cardiovocal syndrome, also known as Ortner's Syndrome, is a rare cause of unilateral vocal fold paralysis (UVFP) associated with cardiac failure. Typically, UVFP is left sided and related to compression or stretching of the left recurrent laryngeal nerve. The original clinical description relates UVFP to left atrium enlargement as heart failure progresses in the context of mitral stenosis. However, other cardiac abnormalities have since been described. Here we present the case of a 7-week old infant who initially came to the attention of pediatric cardiology due to failure to thrive in the context of a grade 4 systolic murmur. Laryngoscopy revealed UVFP on the left side. Echocardiography and MRI scanning confirmed atrial and ventricular septal defects and pulmonary artery dilatation as the likely cause of left recurrent laryngeal dysfunction. Keywords: Cardiovocal syndrome, Dilated, Pulmonary artery, Ortner's syndrome, Left recurrent laryngeal nerv

Pediatric Myofibroma of the Palate with Ulceration and Bone Destruction

Myofibroma is a rare benign neoplasm occurring in the head and neck, arising primarily in infants and children. Frequently, myofibromas grow rapidly leading to suspicion of malignancy and the potential for overaggressive surgical excision. We aim to report a rare case of myofibroma with ulceration and bone destruction. A nine-year-old female presented with an ulcerated left hard palate mass. Open biopsy was performed with pathology suggestive of myofibroma. A left partial maxillectomy and reconstruction with a buccal advancement flap were performed. Final pathology confirmed the diagnosis of a benign myofibroma. Myofibroma is a rare benign tumor of the head and neck which must be considered in the differential diagnosis by the clinician and the pathologist in order to prevent inappropriate and/or overaggressive treatment

Faecal calprotectin: Marker of intestinal inflammatory process in anorexia nervosa? A preliminary study

International audiencePurpose: Anorexia Nervosa (AN) is a serious and potentially lethal mental disorder characterised by a deliberate quest to reduce one's weight. It can have multiple physical and psychological consequences. The clinical presentation of AN can include gastrointestinal symptoms, however, the pathophysiology of these symptoms in the context of AN remains uncertain. It is hypothesised that patients with AN may have an increase in intestinal permeability, which could lead to an increase in faecal calprotectin (fCP), a marker of intestinal inflammation. No relation between AN and elevation of fCP has been previously described in literature. Methods: Eight patients hospitalised for AN have a dosage of fCP. Results: Calprotectine was found to be elevated in 50% of cases, with or without any underlying comorbid gastrointestinal disease. Only the duration of illness tended to be associated with the increase in fCP suggesting a greater alteration as a function related to the time of denutrition. Conclusion: Although these findings provide insights in the potential pathophysiology of gastrointestinal symptoms in AN, further studies that evaluate the factors associated with elevated fCP in patients with AN are needed

Trends in the incidence of new-onset anorexia nervosa and atypical anorexia nervosa among youth during the COVID-19 pandemic in Canada

IMPORTANCE The COVID-19 pandemic has had considerable mental health consequences for children and adolescents, including the exacerbation of previously diagnosed eating disorders. Whether the pandemic is a factor associated with the concomitant increase in new-onset anorexia nervosa or atypical anorexia nervosa remains unknown. OBJECTIVE To assess the incidence and severity of newly diagnosed anorexia nervosa or atypical anorexia nervosa in a national sample of youth before and during the first wave of the COVID-19 pandemic. DESIGN, SETTING, AND PARTICIPANTS This repeated cross-sectional study analyzed new eating disorder assessments that were conducted at 6 pediatric tertiary-care hospitals in Canada between January 1, 2015, and November 30, 2020. Patients aged 9 to 18 years with a new anorexia nervosa or atypical anorexia nervosa diagnosis at the index assessment were included. EXPOSURES COVID-19–associated public health confinement measures during the first wave of the pandemic (March 1 to November 30, 2020). MAIN OUTCOMES AND MEASURES Primary outcomes were the incidence and hospitalization rates within 7 days of de novo anorexia nervosa or atypical anorexia nervosa diagnosis. Event rate trends during the first wave were compared with trends in the 5-year prepandemic period (January 1, 2015, to February 28, 2020) using an interrupted time series with linear regression models. Demographic and clinical variables were compared using a χ2 test for categorical data and t tests for continuous data. RESULTS Overall, 1883 children and adolescents with newly diagnosed anorexia nervosa or atypical anorexia nervosa (median [IQR] age, 15.9 [13.8-16.9] years; 1713 female patients [91.0%]) were included. Prepandemic anorexia nervosa or atypical anorexia nervosa diagnoses were stable over time (mean [SD], 24.5 [1.6] cases per month; β coefficient, 0.043; P = .33). New diagnoses increased during the first wave of the pandemic to a mean (SD) of 40.6 (20.1) cases per month with a steep upward trend (β coefficient, 5.97; P < .001). Similarly, hospitalizations for newly diagnosed patients increased from a mean (SD) of 7.5 (2.8) to 20.0 (9.8) cases per month, with a significant increase in linear trend (β coefficient, −0.008 vs 3.23; P < .001). These trends were more pronounced in Canadian provinces with higher rates of COVID-19 infections. Markers of disease severity were worse among patients who were diagnosed during the first wave rather than before the pandemic, including more rapid progression (mean [SD], 7.0 [4.2] months vs 9.8 [7.4] months; P < .001), greater mean (SD) weight loss (19.2% [9.4%] vs 17.5% [9.6%]; P = .01), and more profound bradycardia (mean [SD] heart rate, 57 [15.8] beats per minute vs 63 [15.9] beats per minute; P < .001). CONCLUSIONS AND RELEVANCE This cross-sectional study found a higher number of new diagnoses of and hospitalizations for anorexia nervosa or atypical anorexia nervosa in children and adolescents during the first wave of the COVID-19 pandemic in Canada. Research is needed to better understand the drivers and prognosis for these patients and to prepare for their mental health needs in the event of future pandemics or prolonged social isolation.Medicine, Faculty ofNon UBCPsychiatry, Department ofReviewedFacultyResearche