Signalling by senescent melanocytes hyperactivates hair growth.

Niche signals maintain stem cells in a prolonged quiescence or transiently activate them for proper regeneration. Altering balanced niche signalling can lead to regenerative disorders. Melanocytic skin nevi in human often display excessive hair growth, suggesting hair stem cell hyperactivity.

Child Media Use During COVID-19: Associations with Contextual and Social-Emotional Factors.

Objective: The aim of this study was to test associations between (1) contextual factors and types of digital media use and (2) types of digital media use and children's social-emotional and sleep outcomes during COVID-19.

Methods: In February to March 2021, 303 parents of elementary schoolers participated in this cross-sectional survey gathering information on demographics, child school format, contextual factors, duration of types of digital media use, social-emotional outcomes, and sleep. Multivariable regressions examined associations outlined in the objective, adjusting for school format, only child, race/ethnicity, and parental stress, depressive symptoms, education, and material hardship.

Remote and Hybrid Schooling During COVID-19: Associations with Child Behavior and Sleep.

Objective: The purpose of this study was to assess the prevalence of child behavior, academic and sleep concerns, and parent stress and depression symptoms during COVID-19; to test associations of parent-child well-being with child school format; and to examine effect moderation by child race/ethnicity and material hardship.

Methods: A total of 305 English-speaking parents of elementary school-age children completed online surveys regarding demographics, child school format, behavior, learning-related experiences, sleep, and parent stress and depression symptoms. Multivariable linear and logistic regression analyses examined associations of school format with child and parent outcomes.

Pediatrician's Beliefs and Practices Around Rapid Infant Weight Gain: A Qualitative Study.

Rapid infant weight gain is a risk factor for later obesity. The objective of this study was to examine primary care pediatricians' beliefs and practices around rapid infant weight gain. Primary care pediatricians (N = 16) participated in a semi-structured interview about infant growth.

Use of the Valve Visualization on Echocardiography Grade Tool Improves Sensitivity and Negative Predictive Value of Transthoracic Echocardiogram for Exclusion of Native Valvular Vegetation.

Background: Transesophageal echocardiography (TEE) remains the preferred test to rule out infective endocarditis (IE) but is resource intensive and carries risk. Multiple studies report low sensitivity of transthoracic echocardiography (TTE) for detection of IE; however, these studies did not account for TTE quality. We test the validity of a simple valve visualization grading tool to stratify TTEs by quality and determine whether a high-quality TTE may be used to exclude valvular vegetation and forgo the need for TEE.

Echocardiographic Assessment of Young Male Draft-Eligible Elite Hockey Players Invited to the Medical and Fitness Combine by the National Hockey League.

The "athletic heart" is characterized by hypertrophy and dilation of the heart, in addition to functional and electrical remodeling. The aim of this study was to provide reference 2-dimensional (2DE) and 3-dimensional (3DE) echocardiographic measurements in a large database on draft-eligible elite ice hockey players and to determine the frequency of occult cardiac anomalies in this cohort of athletes. In this prospective cohort study, we performed a comprehensive cardiac assessment of the 100 top draft picks selected by the National Hockey League.

Development of an Educational Strategy and Decision Support Tool to Enhance Appropriate Use of Stress Echocardiography at a Large Academic Medical Center: A Prospective, Pre- and Postintervention Analysis.

Background: Despite previous studies demonstrating suboptimal appropriate use of stress echocardiography (SE), few interventions have been demonstrated to improve its appropriate use. The aim of this study was to develop a novel mechanism to improve the appropriateness of SE by implementing a point-of-care decision support tool and ordering requisition coupled with an educational strategy.

Methods: A prospective pre- and postintervention analysis was conducted.

The HIVToolbox 2 web system integrates sequence, structure, function and mutation analysis.

There is enormous interest in studying HIV pathogenesis for improving the treatment of patients with HIV infection. HIV infection has become one of the best-studied systems for understanding how a virus can hijack a cell. To help facilitate discovery, we previously built HIVToolbox, a web system for visual data mining.

Vascular imaging in diabetes.

Diabetes is a global epidemic affecting individuals of all socioeconomic backgrounds. Despite intensive efforts, morbidity and mortality secondary to the micro- and macrovascular complications remain unacceptably high. As a result, the use of imaging modalities to determine the underlying pathophysiology, early onset of complications, and disease progression has become an integral component of the management of such individuals.

Lack of difference in T wave variability between patients at risk of sudden cardiac death and healthy subjects.

Background: T wave variability (Tvar) is a proposed method to predict sudden cardiac death (SCD). The purpose of this trial was to evaluate the reproducibility of Tvar measurements over time and demonstrate a difference in Tvar between patient populations at risk for ventricular arrhythmias and healthy subjects.

Methods: Sixty subjects were enrolled in into 3 groups: healthy subjects (Population I), patients at high risk of SCD (Population II), and patients with a recent ventricular tachyarrhythmia event (Population III).

Predictors of normal coronary arteries at coronary angiography.

Background: Coronary angiograms are important in the diagnostic workup of patients with suspected coronary artery disease. However, little is known about the clinical predictors of normal angiograms and whether this rate varies across different cardiac centers in Ontario.

Methods: We conducted a study using the Cardiac Care Network Variations in Revascularization Practice in Ontario database of 2,718 patients undergoing an index cardiac catheterization for an indication of stable angina between April 2006 and March 2007 at one of 17 cardiac hospitals in Ontario.

Angiotensin converting enzyme-2 confers endothelial protection and attenuates atherosclerosis.

The endothelium plays a central role in the maintenance of vascular homeostasis. One of the main effectors of endothelial dysfunction is ANG II, and pharmacological approaches to limit ANG II bioactivity remain the cornerstone of cardiovascular therapeutics. Angiotensin converting enzyme-2 (ACE2) has been identified as a critical negative modulator of ANG II bioactivity, counterbalancing the effects of ACE in determining net tissue ANG II levels; however, the role of ACE2 in the vasculature remains unknown.

NMRES: an artificial intelligence expert system for quantification of cardiac metabolites from 31phosphorus nuclear magnetic resonance spectroscopy.

The application of high-resolution 31Phosphorus Nuclear Magnetic Resonance (31P NMR) Spectroscopy in biology and medicine has provided new insights into biochemical processes and also a unique assessment of metabolites. However, accurate quantification of biological NMR spectra is frequently complicated by: (a) non-Lorentzian form of peak lineshapes, (b) contamination of peak signals by neighboring peaks, (c) presence of broad resonances, (d) low signal-to-noise ratios, and (e) poorly defined sloping baselines. Our objectives were to develop an expert system that captures and formalizes 31P NMR spectroscopists' expert knowledge, and to provide a reliable, efficient, and automated system for the interpretation of biological spectra.