Viscosity-dependent determinants of Campylobacter jejuni impacting the velocity of flagellar motility.

IMPORTANCE: Bacteria can adapt flagellar motor output in response to the load that the extracellular milieu imparts on the flagellar filament to enable propulsion. Bacteria can adapt flagellar motor output in response to the load that the extracellular milieu imparts on the flagellar filament to enable propulsion through diverse environments. These changes may involve increasing power and torque in high-viscosity environments or reducing power and flagellar rotation upon contact with a surface. C. jejuni swimming velocity in low-viscosity environments is comparable to other bacterial flagellates and increases significantly as external viscosity increases. In this work, we provide evidence that the mechanics of the C. jejuni flagellar motor has evolved to naturally promote high swimming velocity in high-viscosity environments. We found that C. jejuni produces VidA and VidB as auxiliary proteins to specifically affect flagellar motor activity in low viscosity to reduce swimming velocity. Our findings provide some of the first insights into different mechanisms that exist in bacteria to alter the mechanics of a flagellar motor, depending on the viscosity of extracellular environments.

Hypoglycemia risk with physical activity in type 1 diabetes: a data-driven approach.

Physical activity (PA) provides numerous health benefits for individuals with type 1 diabetes (T1D). However, the threat of exercise-induced hypoglycemia may impede the desire for regular PA. Therefore, we aimed to study the association between three common types of PA (walking, running, and cycling) and hypoglycemia risk in 50 individuals with T1D. Real-world data, including PA duration and intensity, continuous glucose monitor (CGM) values, and insulin doses, were available from the Tidepool Big Data Donation Project. Participants' mean (SD) age was 38.0 (13.1) years with a mean (SD) diabetes duration of 21.4 (12.9) years and an average of 26.2 weeks of CGM data available. We developed a linear regression model for each of the three PA types to predict the average glucose deviation from 70 mg/dl for the 2 h after the start of PA. This is essentially a measure of hypoglycemia risk, for which we used the following predictors: PA duration (mins) and intensity (calories burned), 2-hour pre-exercise area under the glucose curve (adjusted AUC), the glucose value at the beginning of PA, and total bolus insulin (units) within 2 h before PA. Our models indicated that glucose value at the start of exercise and pre-exercise glucose adjusted AUC (p < 0.001 for all three activities) were the most significant predictors of hypoglycemia. In addition, the duration and intensity of PA and 2-hour bolus insulin were weakly associated with hypoglycemia for walking, running, and cycling. These findings may provide individuals with T1D with a data-driven approach to preparing for PA that minimizes hypoglycemia risk.

Impact of Traditional Versus Flavored Tongue Depressors on Pediatric Oropharynx Exam.

We compared patient-reported discomfort associated with oropharynx examination using traditional (unflavored) versus flavored tongue depressors among pediatric patients presenting to the emergency department in a single-blinded, placebo-controlled randomized trial using a convenience sample ages 3 to 12 years. Our primary outcome was patient discomfort. Secondary outcomes included provider perceptions of patient discomfort, provider-reported examination ease, and caregiver perceptions of patient discomfort. Of 96 recruited patients, 92 (95.8%) completed the study. Forty-six (50%) were randomized to a traditional tongue depressor. Mean patient-reported oropharynx examination discomfort scores were 2.3 cm (95% confidence interval = 1.4-3.2 cm) with traditional tongue depressors versus 1.9 cm (95% confidence interval = 1.0-2.8 cm) with flavored tongue depressors ( P = .72). There were similarly no significant differences between the 2 arms with regard to any of the secondary outcomes. We conclude that the use of flavored tongue depressors does not appear to significantly alleviate discomfort associated with examination of the oropharynx in pediatric patients.

Association of Salivary MicroRNA Changes With Prolonged Concussion Symptoms.

Importance: Approximately one-third of children who experience a concussion develop prolonged concussion symptoms. To our knowledge, there are currently no objective or easily administered tests for predicting prolonged concussion symptoms. Several studies have identified alterations in epigenetic molecules known as microRNAs (miRNAs) following traumatic brain injury. No studies have examined whether miRNA expression can detect prolonged concussion symptoms. Objective: To evaluate the efficacy of salivary miRNAs for identifying children with concussion who are at risk for prolonged symptoms. Design, Setting, and Participants: This prospective cohort study at the Penn State Medical Center observed 52 patients aged 7 to 21 years presenting for evaluation of concussion within 14 days of initial head injury, with follow-up at 4 and 8 weeks. Exposures: All patients had a clinical diagnosis of concussion. Main Outcomes and Measures: Salivary miRNA expression was measured at the time of initial clinical presentation in all patients. Patients with a Sport Concussion Assessment Tool (SCAT3) symptom score of 5 or greater on self-report or parent report 4 weeks after injury were designated as having prolonged symptoms. Results: Of the 52 included participants, 22 (42%) were female, and the mean (SD) age was 14 (3) years. Participants were split into the prolonged symptom group (n = 30) and acute symptom group (n = 22). Concentrations of 15 salivary miRNAs spatially differentiated prolonged and acute symptom groups on partial least squares discriminant analysis and demonstrated functional relationships with neuronal regulatory pathways. Levels of 5 miRNAs (miR-320c-1, miR-133a-5p, miR-769-5p, let-7a-3p, and miR-1307-3p) accurately identified patients with prolonged symptoms on logistic regression (area under the curve, 0.856; 95% CI, 0.822-0.890). This accuracy exceeded accuracy of symptom burden on child (area under the curve, 0.649; 95% CI, 0.388-0.887) or parent (area under the curve, 0.562; 95% CI, 0.219-0.734) SCAT3 score. Levels of 3 miRNAs were associated with specific symptoms 4 weeks after injury; miR-320c-1 was associated with memory difficulty (R, 0.55; false detection rate, 0.02), miR-629 was associated with headaches (R, 0.47; false detection rate, 0.04), and let-7b-5p was associated with fatigue (R, 0.45; false detection rate, 0.04). Conclusions and Relevance: Salivary miRNA levels may identify the duration and character of concussion symptoms. This could reduce parental anxiety and improve care by providing a tool for concussion management. Further validation of this approach is needed.

Morel-LAvallee lesion initially diagnosed as quadriceps contusion: ultrasound, MRI, and importance of early intervention.

Morel-Lavallee lesions (MLL) are rare, closed degloving injuries caused by trauma that delivers a shearing force to the soft tissue most commonly of the hip. If not treated in the acute and subacute setting these lesions are often complicated by re-accumulation of fluid, infection, or chronic pain. We present a unique case of a recurrent, massive medial knee/thigh MLL in which proper treatment was delayed due to initial diagnosis of a quadriceps contusion. We describe the ultrasound and magnetic resonance imaging findings of this patient and based on a review of recent literature propose that the initial management should have included early drainage/debridement, which likely could have prevented recurrence and significantly shortened the clinical course.

Management of acute asthma in the emergency department.

Asthma is primarily a clinical diagnosis that is made from a combination of historical features and clinical examination findings. The mainstay of asthma treatment includes short-acting beta agonist therapy (albuterol) and steroids. Handheld inhalers are sufficient for most inhaled therapy; all patients on inhalers should be provided with a spacer. The severity of asthma exacerbations is determined by 3 features: (1) clinical presentation, (2) peak expiratory flow rates, and (3) vital signs. Additional testing, such as chest x-ray and blood gas measurements, is reserved for select patients. Spirometry aids in the diagnosis of asthma and measurement of severity, but it is not always required, nor should it be solely relied upon to make disposition decisions. Inhaled ipratropium decreases hospitalization rates, and it should be routinely used. Levalbuterol provides little to no advantage over less-expensive racemic albuterol. Noninvasive positive pressure ventilation may be utilized in patients with moderate to severe exacerbations. Ketamine may be considered in severe exacerbations, but it should not be used routinely. Magnesium sulfate may be beneficial in severe asthma exacerbations, but routine use for mild to moderate exacerbations is not indicated.