Natural history of aortic root dilation through young adulthood in a hypermobile Ehlers-Danlos syndrome cohort.

Hypermobile Ehlers-Danlos syndrome (hEDS) is a common inherited connective tissue disorder characterized by joint hypermobility. The natural history of aortic root dilation (AoD), a potential complication of EDS, has not been well characterized in this population. We describe the natural history of aortic root size in a large cohort of patients with hEDS. A cohort of 325 patients with HEDS was identified at Cincinnati Children's Hospital Medical Center (CCHMC), including 163 patients from a previous study. Medical records were reviewed and each participant's height, weight, and aortic dimensions from up to four echocardiograms were documented. Aortic root z-scores were calculated using two established formulas based on age (Boston or Devereux). Overall prevalence of AoD and prevalence by age were calculated and longitudinal regression was performed. The prevalence of AoD with a z-score ≥ 2.0 was 14.2% (46/325) and with a z-score of ≥3.0 was 5.5% (18/325). No significant increases in z-score were seen over time for patients with multiple echocardiograms. Participants under the age of 15 years had an average decline of 0.1 standard deviations (SDs)/year. No significant change was found after 15 of age. Between the ages of 15 and 21 years, Boston z-scores were 0.96 higher than Devereux z-scores. The nearly 1 z-score unit difference between formulas indicates caution prior to diagnosing AoD in patients with hEDS. In light of the low prevalence and lack of progression of AoD, routine echocardiograms may not be warranted for pediatric patients with hEDS.

Disruption of an ant-plant mutualism shapes interactions between lions and their primary prey.

Mutualisms often define ecosystems, but they are susceptible to human activities. Combining experiments, animal tracking, and mortality investigations, we show that the invasive big-headed ant (Pheidole megacephala) makes lions (Panthera leo) less effective at killing their primary prey, plains zebra (Equus quagga). Big-headed ants disrupted the mutualism between native ants (Crematogaster spp.) and the dominant whistling-thorn tree (Vachellia drepanolobium), rendering trees vulnerable to elephant (Loxodonta africana) browsing and resulting in landscapes with higher visibility. Although zebra kills were significantly less likely to occur in higher-visibility, invaded areas, lion numbers did not decline since the onset of the invasion, likely because of prey-switching to African buffalo (Syncerus caffer). We show that by controlling biophysical structure across landscapes, a tiny invader reconfigured predator-prey dynamics among iconic species.

Critical COVID-19 Complicating Recovery From Surgical Repair of Congenital Heart Disease.

This case highlights the need for accurate and rapid testing for severe acute respiratory syndrome coronavirus 2 and also underscores the need for caregivers to remain vigilant for coronavirus disease 2019 in the postoperative setting despite negative preoperative testing.

Demographic consequences of mutualism disruption: Browsing and big-headed ant invasion drive acacia population declines.

Across the globe, biological invasions have disrupted mutualisms, producing reverberating consequences for ecosystems. Although invasive species frequently trigger mutualism disruptions, few studies have quantified the demographic mechanisms by which mutualism breakdown may generate population effects. In a Kenyan savanna, the invasive big-headed ant (Pheidole megacephala) has disrupted a foundational mutualism between the monodominant whistling-thorn tree (Acacia drepanolobium) and native ants (Crematogaster spp.) that deter browsing by large mammalian herbivores. We conducted experiments to quantify the demographic consequences of this mutualism disruption in the presence and absence of large mammalian herbivores. Invasion by P. megacephala exacerbated population declines of A. drepanolobium, primarily through decreased survival and reproduction of adult trees. However, these fitness reductions were small compared to those resulting from the presence of large mammalian herbivores, which negatively impacted growth and survival. Contrary to expectation, the expulsion of metabolically costly Crematogaster mutualists by P. megacephala did not result in higher population growth rates for trees protected from large mammalian herbivores. Our results suggest that invasive P. megacephala may impose a direct metabolic cost to trees exceeding that of native mutualists while providing no protection from browsing by large mammalian herbivores. Across landscapes, we expect that invasion by P. megacephala will reduce A. drepanolobium populations, but that the magnitude and demographic pathways of this effect will hinge on the presence and abundance of browsers.

Virtual multispecialty point-of-care ultrasound rotation for fourth-year medical students during COVID-19: Innovative teaching techniques improve ultrasound knowledge and image interpretation.

Objectives: Point-of-care ultrasound (PoCUS) has been integrated into undergraduate medical education. The COVID-19 pandemic forced medical schools to evolve clinical rotations to minimize interruption through implementation of novel remote learning courses. To address the students' need for remote clinical education, we created a virtual PoCUS course for our fourth-year class. We present details of the course's development, implementation, quality improvement processes, achievements, and limitations. Methods: A virtual PoCUS course was created for 141 fourth-year medical students. The learning objectives included ultrasound physics, performing and interpreting ultrasound applications, and incorporating PoCUS into clinical decisions and procedural guidance. Students completed a 30-question pre- and posttest focused on ultrasound and knowledge of clinical concepts. PoCUS educators from 10 different specialties delivered the course over 10 days using video-conferencing software. Students watched live scanning demonstrations and practiced ultrasound probe maneuvers using a cellular telephone to simulate ultrasound probe. Students completed daily course evaluations that were used as a continuous needs assessment to make improvements. Results: A total of 141 students participated in the course; all received a passing grade. The mean pre- and posttest scores improved from 58% to 88% (p < 0.001) through the course duration. Daily evaluations revealed the percentage of students who rated the course's live scanning sessions and didactic components as "very well" increased from 32.7% on day 1 to 69.7% on day 10. The end-of-course evaluation revealed that 91% of students agreed they received effective teaching. Conclusions: In response to the COVID-19 pandemic, our multispecialty faculty expeditiously developed a virtual PoCUS curriculum for the entire fourth-year class. This innovative course improved students' ultrasound knowledge, image interpretation, and clinical application while utilizing novel techniques to teach a hands-on skill virtually. As the demand for PoCUS instruction continues to increase, the accessibility of virtual training and blended learning will be beneficial.

Frenemy at the gate: Invasion by Pheidole megacephala facilitates a competitively subordinate plant ant in Kenya.

Biological invasions can lead to the reassembly of communities and understanding and predicting the impacts of exotic species on community structure and functioning are a key challenge in ecology. We investigated the impact of a predatory species of invasive ant, Pheidole megacephala, on the structure and function of a foundational mutualism between Acacia drepanolobium and its associated acacia-ant community in an East African savanna. Invasion by P. megacephala was associated with the extirpation of three extrafloral nectar-dependent Crematogaster acacia ant species and strong increases in the abundance of a competitively subordinate and locally rare acacia ant species, Tetraponera penzigi, which does not depend on host plant nectar. Using a combination of long-term monitoring of invasion dynamics, observations and experiments, we demonstrate that P. megacephala directly and indirectly facilitates T. penzigi by reducing the abundance of T. penzigi's competitors (Crematogaster spp.), imposing recruitment limitation on these competitors, and generating a landscape of low-reward host plants that favor colonization and establishment by the strongly dispersing T. penzigi. Seasonal variation in use of host plants by P. megacephala may further increase the persistence of T. penzigi colonies in invaded habitat. The persistence of the T. penzigi-A. drepanolobium symbiosis in invaded areas afforded host plants some protection against herbivory by elephants (Loxodonta africana), a key browser that reduces tree cover. However, elephant damage on T. penzigi-occupied trees was higher in invaded than in uninvaded areas, likely owing to reduced T. penzigi colony size in invaded habitats. Our results reveal the mechanisms underlying the disruption of this mutualism and suggest that P. megacephala invasion may drive long-term declines in tree cover, despite the partial persistence of the ant-acacia symbiosis in invaded areas.

Thoracic duct embolization in kaposiform lymphangiomatosis.

An 11-year-old girl with kaposiform lymphangiomatosis presented with recurrent chylous pericardial effusions that were refractory to pericardial drainage and medical therapy. Magnetic resonance imaging demonstrated a prominent lymphatic duct with anterior mediastinal extension into the left clavicular region and a region of high signal that was favored to represent a low-flow lymphatic malformation. The patient underwent direct access thoracic duct lymphangiography with thoracic duct embolization and sclerotherapy of the large left-sided neck and pericardial lymphatic malformation. After the procedure, her pericardial effusions resolved, and she has remained asymptomatic for 15 months.

Histopathological abnormalities in the central arteries and veins of Fontan subjects.

OBJECTIVE: Fontan circulations have obligatory venous hypertension, depressed cardiac output and abnormal arterial elastance. Ventriculovascular coupling is known to be abnormal, but the underlying mechanisms are poorly defined. We aim to describe the histopathological features of vascular remodelling encountered in the central arteries and veins in the Fontan circulation as a possible underlying pathological representation of abnormal ventriculovascular coupling. METHODS: Postmortemvasculature (inferior vena cava (IVC), superior vena cava (SVC), pulmonary artery (PA), pulmonary vein (PV) and aorta) of 13 patients with a Fontan circulation (mean age 29.9 years, range 9.0-59.8 years) and 2 biventricular controls (ages 17.9 and 30.2 years) was examined. RESULTS: IVC and SVC: Eccentric and variable intimal fibromuscular proliferation occurred in 11 Fontan subjects. There was variable loss of medial smooth muscle bundles with reciprocal replacement with dense collagenous tissue.PA: Similar intimal fibromuscular proliferation was seen; however, these intimal changes were accompanied by medial thinning rather than expansion, medial myxoid degeneration and elastic alteration.PV: The PVs demonstrated intimal fibroproliferation and disorganisation of the muscular media.Aorta: The aortic lamina intima was thickened, with associated fibromuscular proliferation and elasticisation. There was also moderate lymphocytic inflammation in the aortic wall. CONCLUSIONS: Vascular architectural remodelling is common in Fontan patients. The central veins demonstrate profound changes of eccentric intimal expansion and smooth muscle replacement with collagen. The pulmonary demonstrated abnormal intimal proliferation, and aortic remodelling was characterised by intima lamina thickening and a moderate degree of aortic wall inflammation.

Impact of barcode medication administration technology on how nurses spend their time on clinical care.

In a time-motion study conducted in a hospital that recently implemented barcode medication administration (BCMA) technology, we found that the BCMA system did not increase the amount of time nurses spend on medication administration activities, and did not compromise the amount of time nurses spent on direct care of patients. Our results should allay concerns regarding the impact of BCMA on nursing workflow.