High risk and low prevalence diseases: Cavernous sinus thrombosis.

INTRODUCTION: Cavernous sinus thrombosis (CST) is a serious condition that carries with it a high rate of morbidity and mortality. OBJECTIVE: This review highlights the pearls and pitfalls of CST, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence. DISCUSSION: CST is a potentially deadly thrombophlebitic disease involving the cavernous sinuses. The most common underlying etiology is sinusitis or other facial infection several days prior to development of CST, though other causes include maxillofacial trauma or surgery, thrombophilia, dehydration, or medications. Staphylococcus aureus, streptococcal species, oral anaerobic species, and gram-negative bacilli are the most frequent bacterial etiologies. The most prevalent presenting signs and symptoms are fever, headache, and ocular manifestations (chemosis, periorbital edema, ptosis, ophthalmoplegia, vision changes). Cranial nerve (CN) VI is the most commonly affected CN, resulting in lateral rectus palsy. Other CNs that may be affected include III, IV, and V. The disease may also affect the pulmonary and central nervous systems. Laboratory testing typically reveals elevated inflammatory markers, and blood cultures are positive in up to 70% of cases. Computed tomography of the head and orbits with intravenous contrast delayed phase imaging is recommended in the ED setting, though magnetic resonance venography demonstrates the highest sensitivity. Management includes resuscitation, antibiotics, and anticoagulation with specialist consultation. CONCLUSION: An understanding of CST can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Workplace Violence in the Pediatric Emergency Department: A National Survey of Physicians in the United States.

OBJECTIVES: Previous work shows that health care workers, and particularly emergency department (ED) staff, are at an above average risk of workplace violence (WPV), defined as verbal threats or physical violence in the workplace. Previous data suggest that staff of a single pediatric ED frequently feel unsafe. The objective of this study was to conduct the first national survey study to assess the prevalence and incidence of WPV in the pediatric ED. METHODS: In this cross-sectional survey study, a representative sample of US pediatric emergency medicine physicians were invited to participate in a national survey adapted from the previously validated Workplace Violence in the Health Sector questionnaire from the World Health Organization. The primary outcome measure was the proportion of physicians who have been exposed to WPV. Rates of exposure to violence, reporting habits, and physician perception of various violence prevention strategies were studied secondarily. RESULTS: Surveys were completed by 207 (45%) invited participants, representing 31 US children's hospitals. The prevalence of WPV exposure was 96%. Physical violence with a weapon was witnessed by 20% of participants. Injuries requiring medical attention or time off work were experienced by 10% of participants. Half of participants never reported violent events. Security guards were welcome by 99%, armed law enforcement officers by 70%, and metal detectors by 81% of physicians. Self-arming was opposed by 85% of respondents. CONCLUSIONS: Exposure to WPV is frequent among pediatric emergency medicine physicians with a prevalence similar to that of general emergency departments. Workplace violence remains underreported. This national survey contributes to the objective evaluation of individual- and systems-level violence prevention interventions.

An Innovative Curriculum For Teaching Transesophageal Echocardiography (TEE) to Emergency Medicine Residents.

BACKGROUND: Focused transesophageal echocardiogram (TEE) can be a valuable tool for emergency physicians (EP) during cardiac arrest. OBJECTIVES: We sought to demonstrate the ability of emergency medicine (EM) residents without prior TEE experience to perform a simulated four-view TEE following a short, flipped conference curriculum. METHODS: This was a prospective, simulation-based study where EM residents participated in the following four-view TEE curriculum: 1 h of online content reviewed prior to a 20-min in-person lecture and 30-min hands-on practice using a TEE trainer. Each resident attended four testing sessions over an 8-week period and performed a total of 25 TEE scans. Each TEE scan was graded in real time using a 10-point checklist by a TEE-credentialed EP. Interrater reliability of the checklist was calculated using the kappa coefficient (κ). A random sample of 10% of the TEE scans were reviewed by a TEE expert using a standard ultrasound 1-5 scale for image acquisition quality, with a "3" considered to be satisfactory. Residents completed an online pretest and posttest. RESULTS: Twenty-four residents participated. Mean pre- and posttest scores were 52% (SD 16) and 92% (SD 12), respectively. Mean TEE scores using the 10-point checklist after sessions one and four were 9.4 (SD 0.4) and 9.7 (SD 0.3), respectively. Mean time to complete each TEE scan after sessions one and four were 118.1 (SD 28.3) and 57.1 (SD 17.0) s, respectively. The κ for the checklist was 1. The median score for the image acquisition review was 3 (interquartile range 3-4). CONCLUSIONS: This simplified flipped conference curriculum can train EM residents to competently perform TEE in a simulated environment.

Tetanus: A Rare Complication of Black Tar Heroin Use.

Tetanus is associated with high morbidity and mortality, although this is rarely encountered in high-income countries. We present a case of tetanus in an unvaccinated patient secondary to black tar heroin use that highlights the importance of considering tetanus in appropriate clinical contexts, harm reduction interventions, and universal tetanus vaccination campaigns.

Can Medical Students Learn and Perform POCUS in the Pediatric Emergency Department? Implementation of a Short Curriculum.

Purpose: To determine medical student ability to accurately obtain and interpret POCUS exams of varying difficulty in the pediatric population after a short didactic and hands-on POCUS course. Methods: Five medical students were trained in four POCUS applications (bladder volume, long bone for fracture, limited cardiac for left ventricular function, & inferior vena cava collapsibility) and enrolled pediatric ED patients. Ultrasound-fellowship-trained emergency medicine physicians reviewed each scan for image quality and interpretation accuracy using the American College of Emergency Physicians' quality assessment scale. We report acceptable scan frequency and medical student vs. Ultrasound-fellowship-trained emergency medicine physician interpretation agreement with 95% confidence intervals (CI). Results: Ultrasound-fellowship-trained emergency medicine physicians graded 51/53 bladder volume scans as acceptable (96.2%; 95% CI 87.3-99.0%) and agreed with 50/53 bladder volume calculations (94.3%; 95% CI 88.1-100%). Ultrasound-fellowship-trained emergency medicine physicians graded 35/37 long bone scans as acceptable (94.6%; 95% CI 82.3-98.5%) and agreed with 32/37 medical student long bone scan interpretations (86.5%; 95% CI 72.0-94.1%). Ultrasound-fellowship-trained emergency medicine physicians graded 116/120 cardiac scans as acceptable (96.7%; 95% CI 91.7-98.7%) and agreed with 111/120 medical student left ventricular function interpretations (92.5%; 95% CI 86.4-96.0%). Ultrasound-fellowship-trained emergency medicine physicians graded 99/117 inferior vena cava scans as acceptable (84.6%; 95% CI 77.0-90.0%) and agreed with 101/117 medical student interpretations of inferior vena cava collapsibility (86.3%; 95% CI 78.9-91.4%). Conclusions: Medical students demonstrated satisfactory ability within a short period of time in a range of POCUS scans on pediatric patients after a novel curriculum. This supports the incorporation of a formal POCUS education into medical school curricula and suggests that novice POCUS learners can attain a measure of competency in multiple applications after a short training course.

Retracing evolution of red fluorescence in GFP-like proteins from Faviina corals.

Proteins of the green fluorescent protein family represent a convenient experimental model to study evolution of novelty at the molecular level. Here, we focus on the origin of Kaede-like red fluorescent proteins characteristic of the corals of the Faviina suborder. We demonstrate, using an original approach involving resurrection and analysis of the library of possible evolutionary intermediates, that it takes on the order of 12 mutations, some of which strongly interact epistatically, to fully recapitulate the evolution of a red fluorescent phenotype from the ancestral green. Five of the identified mutations would not have been found without the help of ancestral reconstruction, because the corresponding site states are shared between extant red and green proteins due to their recent descent from a dual-function common ancestor. Seven of the 12 mutations affect residues that are not in close contact with the chromophore and thus must exert their effect indirectly through adjustments of the overall protein fold; the relevance of these mutations could not have been anticipated from the purely theoretical analysis of the protein's structure. Our results introduce a powerful experimental approach for comparative analysis of functional specificity in protein families even in the cases of pronounced epistasis, provide foundation for the detailed studies of evolutionary trajectories leading to novelty and complexity, and will help rational modification of existing fluorescent labels.

Theoretical and experimental studies of tyrosyl hydroperoxide formation in the presence of H-bond donors.

Oxidative damage to biomolecules such as lipids, proteins, nucleotides, and sugars has been implicated in the pathogenesis of various diseases. Superoxide radical anion (O 2 (*-)) addition to nitrones bearing an amide N-H has been shown to be more favored as compared to other nitrones [ Villamena, F. A. , ( 2007) J. Am. Chem. Soc. 129, 8177- 8191 ]. It has also been demonstrated by others [ Winterbourn, C. C. , ( 2004) Biochem. J. 381, 241- 248 ] that O 2 (*-) addition to tyrosine to form hydroperoxide is favored in the presence of basic amino groups, but the mechanism for this observation remains obscure. We, therefore, hypothesized that the alpha-effect resulting from the interaction of O 2 (*-) with N-H can play a crucial role in the enhancement of hydroperoxide formation. Understanding this phenomenon is important in the elucidation of mechanisms leading to oxidative stress in cellular systems. Computational (at the PCM/B3LYP/6-31+G**//B3LYP/6-31G level of theory) as well as experimental studies were carried out to shed insights into the effect of amide or amino N-H on the enhancement (or stabilization) of hydroperoxide formation in tyrosine. H-bond interaction of amino acid group with O 2 (*-) results in the perturbation of the spin and charge densities of O 2 (*-). A similar phenomenon has been predicted for non-amino acids bearing H-bond donor groups. Using the FOX assay, tyrosyl hydroperoxide formation was enhanced in the presence of H-bond donors from amino acids and non-amino acids. The role of H-bonding in either stabilizing the hydroperoxide adduct or facilitating O 2 (*-) addition via an alpha-effect was further theoretically investigated, and results show that the latter mechanism is more thermodynamically preferred. This study provides new mechanistic insights in the initiation of oxidative modification to tyrosyl radical.

Diversity and evolution of coral fluorescent proteins.

GFP-like fluorescent proteins (FPs) are the key color determinants in reef-building corals (class Anthozoa, order Scleractinia) and are of considerable interest as potential genetically encoded fluorescent labels. Here we report 40 additional members of the GFP family from corals. There are three major paralogous lineages of coral FPs. One of them is retained in all sampled coral families and is responsible for the non-fluorescent purple-blue color, while each of the other two evolved a full complement of typical coral fluorescent colors (cyan, green, and red) and underwent sorting between coral groups. Among the newly cloned proteins are a "chromo-red" color type from Echinopora forskaliana (family Faviidae) and pink chromoprotein from Stylophora pistillata (Pocilloporidae), both evolving independently from the rest of coral chromoproteins. There are several cyan FPs that possess a novel kind of excitation spectrum indicating a neutral chromophore ground state, for which the residue E167 is responsible (numeration according to GFP from A. victoria). The chromoprotein from Acropora millepora is an unusual blue instead of purple, which is due to two mutations: S64C and S183T. We applied a novel probabilistic sampling approach to recreate the common ancestor of all coral FPs as well as the more derived common ancestor of three main fluorescent colors of the Faviina suborder. Both proteins were green such as found elsewhere outside class Anthozoa. Interestingly, a substantial fraction of the all-coral ancestral protein had a chromohore apparently locked in a non-fluorescent neutral state, which may reflect the transitional stage that enabled rapid color diversification early in the history of coral FPs. Our results highlight the extent of convergent or parallel evolution of the color diversity in corals, provide the foundation for experimental studies of evolutionary processes that led to color diversification, and enable a comparative analysis of structural determinants of different colors.

Adaptive evolution of multicolored fluorescent proteins in reef-building corals.

Here we investigate the evolutionary scenarios that led to the appearance of fluorescent color diversity in reef-building corals. We show that the mutations that have been responsible for the generation of new cyan and red phenotypes from the ancestral green were fixed with the help of positive natural selection. This fact strongly suggests that the color diversity is a product of adaptive evolution. An unexpected finding was a set of residues arranged as an intermolecular binding interface, which was also identified as a target of positive selection but is nevertheless not related to color diversification. We hypothesize that multicolored fluorescent proteins evolved as part of a mechanism regulating the relationships between the coral and its algal endosymbionts (zooxanthellae). We envision that the effect of the proteins' fluorescence on algal physiology may be achieved not only through photosynthesis modulation, but also through regulatory photosensors analogous to phytochromes and cryptochromes of higher plants. Such a regulation would require relatively subtle, but spectrally precise, modifications of the light field. Evolution of such a mechanism would explain both the adaptive diversification of colors and the coevolutionary chase at the putative algae-protein binding interface in coral fluorescent proteins.