Impact of modern recreational conveyances on rates of pediatric craniofacial fractures.

Objective: Trauma remains the leading cause of death for children over a year old. Motorized recreational conveyances (RCs) adds another potential cause of pediatric trauma. This study aims to determine the impact of adding electric motors to RCs on the severity and frequency of pediatric injuries and craniofacial fractures. Methods: Pediatric trauma information was obtained from the National Electronic Injury Surveillance System (NEISS) database between 2012 and 2021. Demographics, injury cause, diagnoses, and incident narrative were collected. Bivariate and multivariate regression analyses were used to determine injury factors associated with serious injuries. Results: One million five hundred ninety-six thousand five hundred fifty-nine encounters were examined; 113,905 (7.1%) were related to pediatric RCs and 5354 (5.4%) of those involved RCs with electric motors. 14.3% of injuries were related to scooters, 18.6% to skateboards, 54.2% to bicycles, and 12.9% to other RCs. There were significant differences in age, sex, race, helmet use, serious injuries, and craniofacial fractures between RC modalities. RC users were more likely to develop facial fractures (OR 2.12; 95%CI 2.01, 2.23; p < .001) and be involved in serious injuries (OR 1.42; 95%CI 1.38, 1.46; p < .001). Compared to their self-propelled counterparts, motorized scooters (OR 2.24; 95%CI 1.86, 2.69; p < .001) but not motorized skateboards (OR 1.01; 95%CI 0.88, 1.17; p = 0.88) were more likely to cause serious injuries. Helmet use was associated with fewer serious injuries (OR 0.5; 95%CI 0.46, 0.54; p < .001), facial fractures (OR 0.48; 95%CI 0.41, 0.55; p < .001), and skull fractures (OR 0.13; 95%CI 0.09, 0.17; p < .001). Conclusions: The addition of electric motors to RCs significantly increases the risk of pediatric craniofacial fractures and serious injuries. Level of Evidence: 3.

Cerebellar Compression by Giant Extracanalicular Osteoma with Central Cholesterol Granuloma.

Temporal bone osteomas comprise 0.1-1% of benign tumors involving the skull, the majority of which arise in the external auditory canal. More rarely, they can arise from the mastoid portion of the temporal bone. These generally present as a slow growing skull base lesion that can cause cosmetic deformity, headache, and/or hearing loss. Here, we report a case of extracanalicular mastoid osteoma uniquely presenting with posterior fossa and cerebellar compression with associated dizziness and imbalance.

A Model Selection Approach for Time Series Forecasting: Incorporating Google Trends Data in Australian Macro Indicators.

This study examined whether the behaviour of Internet search users obtained from Google Trends contributes to the forecasting of two Australian macroeconomic indicators: monthly unemployment rate and monthly number of short-term visitors. We assessed the performance of traditional time series linear regression (SARIMA) against a widely used machine learning technique (support vector regression) and a deep learning technique (convolutional neural network) in forecasting both indicators across different data settings. Our study focused on the out-of-sample forecasting performance of the SARIMA, SVR, and CNN models and forecasting the two Australian indicators. We adopted a multi-step approach to compare the performance of the models built over different forecasting horizons and assessed the impact of incorporating Google Trends data in the modelling process. Our approach supports a data-driven framework, which reduces the number of features prior to selecting the best-performing model. The experiments showed that incorporating Internet search data in the forecasting models improved the forecasting accuracy and that the results were dependent on the forecasting horizon, as well as the technique. To the best of our knowledge, this study is the first to assess the usefulness of Google search data in the context of these two economic variables. An extensive comparison of the performance of traditional and machine learning techniques on different data settings was conducted to enable the selection of an efficient model, including the forecasting technique, horizon, and modelling features.

Cadaveric emergency cricothyrotomy training for non-surgeons using a bronchoscopy-enhanced curriculum.

BACKGROUND: Emergency cricothyrotomy training for non-surgeons is important as rare "cannot intubate or oxygenate events" may occur multiple times in a provider's career when surgical expertise is not immediately available. However, such training is highly variable and often infrequent, therefore, enhancing these experiences is important. RESEARCH QUESTION: Is bronchoscopy-enhanced cricothyrotomy training in cadavers feasible, and what are the potential benefits provided by this innovation for trainees? METHODS: This study was performed during implementation of a new program to train non-surgeon providers on cadaveric donors on our campus. Standard training with an instructional video and live coaching was enhanced by bronchoscopic visualization of the trachea allowing participants to review their technique after performing scalpel and Seldinger-technique procedures, and to review their colleagues' technique on live video. Feasibility was measured through assessing helpfulness for trainees, cost, setup time, quality of images, and operator needs. Footage from the bronchoscopy recordings was analyzed to assess puncture-to-tube time, safety errors, and evidence for a training effect within groups. Participants submitted pre- and post-session surveys assessing their levels of experience and gauging their confidence and anxiety with cricothyrotomies. RESULTS: The training program met feasibility criteria for low costs (<200 USD/donor), setup time (<30 minutes/donor), and operator needs (1/donor). Furthermore, all participants rated the cadaveric session as helpful. Participants demonstrated efficient technique, with a median puncture-to-tube time of 48.5 seconds. Bronchoscopy recordings from 24 analyzed videos revealed eight instances of sharp instruments puncturing the posterior tracheal wall (33% rate), and two instances of improper tube placement (8% rate). Sharp instruments reached potentially dangerous insertion depths beyond the midpoint of the anterior-posterior diameter of the trachea in 58.3% of videos. Bronchoscopic enhancement was rated as quite or extremely helpful for visualizing the trachea (83.3%) and to assess depth of instrumentation (91.7%). There was a significant average increase in confidence (64.4%, P<0.001) and average decrease in performance anxiety (-11.6%, P = 0.0328) after the session. A training effect was seem wherein the last trainee in each group had no posterior tracheal wall injuries. INTERPRETATION: Supplementing cadaveric emergent cricothyrotomy training programs with tracheal bronchoscopy is feasible, helpful to trainees, and meets prior documented times for efficient technique. Furthermore, it was successful in detecting technical errors that would have been missed in a standard training program. Bronchoscopic enhancement is a valuable addition to cricothyrotomy cadaveric training programs and may help avoid real-life complications.

Effect of the COVID-19 Pandemic on Otolaryngology Trainee Surgical Case Numbers: A Multi-institutional Review.

OBJECTIVE: To determine the effect of the initiation of COVID-19-related restrictions on the volume of surgical cases performed by otolaryngology trainees. STUDY DESIGN: Multi-institutional retrospective analysis of resident surgical case logs. SETTING: Accredited residency training programs in otolaryngology head and neck surgery. METHODS: Resident surgical case logs were combined from 6 residency training programs from different regions of the United States. Case volumes were compared between the calendar year before March 1, 2020, and the year afterward. Subgroup analyses were performed for the type of hospital (university, pediatric, veteran, county) and the key index cases by subspecialty. RESULTS: All 6 participating residency programs had a decrease in resident operative case volume. Surgical volume decreased from a mean of 6014 to 4161 (P < .05). There were decreases observed in key index cases in every subspecialty (P < .01), without statistical differences seen among subspecialties. There were decreases observed in every hospital type (university, pediatric, veteran, county) without statistical differences among types. Postgraduate year 5 residents were the most affected by volume reductions (51.6%), and postgraduate year 3 residents were the least affected (1.4%). CONCLUSION: In the year following initiation of COVID-19-related restrictions, there was a significant decrease in trainee surgical case volumes within residencies for otolaryngology-head and neck surgery. There were no statistical differences in the volume decreases seen at different institutions, among hospital types, or within various subspecialties.

Transient patulous eustachian tube in severe anorexia nervosa: A prospective observational study.

Objectives: To understand the presence of transient autophony symptoms in patients being treated for severe anorexia nervosa (AN), and whether those symptoms were due to patulous eustachian tube (PET). Methods: A prospective observational study was performed in patients requiring admission for treatment of severe AN. All enrolled patients completed The Eustachian Tube Dysfunction Questionnaire (ETDQ-7) and were screened for symptoms of autophony. If patients reported autophony and had a score of ≥14.5 on the ETDQ-7 they were asked to undergo comprehensive audiological testing and an evaluation with an otolaryngologist. Results: Of the 73 patients enrolled in the study, 35 patients (44%) reported autophony and 36 (49%) scored 14.5 or higher on the ETDQ-7. Of the 16 (22%) patients who had both autophony and an ETDQ-7 score of 14.5 or higher, 7 patient s (representing 11 symptomatic ears) underwent evaluations by audiology and otolaryngology. Every evaluation of a symptomatic ear revealed objective evidence of PET. Nine of 11 (81.8%) symptomatic ears had subjectively resolved within 12 days of admission after nutritional rehabilitation and weight gain. Conclusion: Transient autophony in severe AN patients is due to PET, and was present in at least 8% of patients within our cohort. Further study is warranted to understand the quality of life impact and pathophysiology of transient PET in this patient population.

Autophony in inpatients with anorexia nervosa or avoidant restrictive food intake disorder.

OBJECTIVE: To assess for the prevalence of autophony, a distressing auditory symptom commonly attributed to patulous eustachian tube, in a cohort of individuals with severe malnourishment due to an eating disorder. METHOD: A cross-sectional survey study was performed. Patients admitted for inpatient medical stabilization of an eating disorder, who were also at low body weight, were asked to complete a survey assessing aural symptoms present in the previous 24 hr, including autophony. Anthropometric data and prealbumin levels were collected. RESULTS: Of 101 patients enrolled, 43 (42.6%) reported symptoms of autophony. The presence of autophony was associated with lower serum prealbumin levels and lower body weight as measured by percentage of ideal body weight. DISCUSSION: Autophony is a commonly reported, albeit rarely discussed, symptom in individuals with severe eating disorders and correlates with degree of malnutrition.

Patient Chief Complaint and Otolaryngology Referral Rationale: Discordance and Opportunities for Quality Improvement.

OBJECTIVE: As medical systems focus on patient satisfaction as an important care outcome, specialty clinics are tasked with continued improvement of patients' experience. When patient expectations for a consultation differ from that of the specialty provider, dissatisfaction with the experience can occur. One source of differing expectations is discordance between the patient's chief complaint and the clinical rationale for the consultation as requested by the referring provider. We sought to better understand when this discordance occurs, as well as factors contributing to this disorientation of patient and provider expectations in a safety net otolaryngology practice. METHODS: A retrospective observational study was performed and records were examined from new patient consultations. Patient questionnaires, including self-reported chief concerns, were compared with the electronic referral documentation. A difference between the patient's Chief Complaint (CC) and Referral Reason (RR) was defined as CC-RR Discordance. Medical records, pre-consultation patient communication, and scheduling data were also reviewed to evaluate contributing factors. RESULTS: Of the 1155 consultations examined, 952 were included in the analysis. A CC-RR Discordance was found in 175 (18.4%) of new-patient encounters, including 117 (12.3%) that were unable to articulate a CC (unsure of the reason for the appointment), and 58 (6.1%) that stated a CC that was different than the RR. The rate of CC-RR Discordance was higher in patients with female sex (P < .05), older age (P < .001), and longer time intervals between referral and appointment (P < .05). Lack of communication with the patient (instructions or referral notification) by the referring provider was not associated with CC-RR Discordance. CONCLUSIONS: Discordance between patient CC and the rationale for a consultation is common in this safety-net otolaryngology practice and may be an important source of patient dissatisfaction. Future opportunities for quality improvement include pre-consultation communication between the specialist and the patient and reducing time intervals between referral and appointment.

3D Printing in Eye Care.

Three-dimensional printing enables precise modeling of anatomical structures and has been employed in a broad range of applications across medicine. Its earliest use in eye care included orbital models for training and surgical planning, which have subsequently enabled the design of custom-fit prostheses in oculoplastic surgery. It has evolved to include the production of surgical instruments, diagnostic tools, spectacles, and devices for delivery of drug and radiation therapy. During the COVID-19 pandemic, increased demand for personal protective equipment and supply chain shortages inspired many institutions to 3D-print their own eye protection. Cataract surgery, the most common procedure performed worldwide, may someday make use of custom-printed intraocular lenses. Perhaps its most alluring potential resides in the possibility of printing tissues at a cellular level to address unmet needs in the world of corneal and retinal diseases. Early models toward this end have shown promise for engineering tissues which, while not quite ready for transplantation, can serve as a useful model for in vitro disease and therapeutic research. As more institutions incorporate in-house or outsourced 3D printing for research models and clinical care, ethical and regulatory concerns will become a greater consideration. This report highlights the uses of 3D printing in eye care by subspecialty and clinical modality, with an aim to provide a useful entry point for anyone seeking to engage with the technology in their area of interest.

Scholarly Research Productivity among Otolaryngology Residency Graduates and its Relationship to Future Academic Achievement.

OBJECTIVE: Scholastic activity through research involvement is a fundamental aspect of a physician's training and may have a significant influence on future academic success. Here, we explore publication rates before, during, and after otolaryngology residency training and whether publication efforts correlate with future academic achievement. METHODS: This cross-sectional analysis included a random sample of 50 otolaryngology residency programs. From these programs, we assembled a list of residents graduating from the years in 2013, 2014, and 2015. Using SCOPUS, PubMed, and Google Scholar, we compiled the publications for each graduate, and data were extracted in an independent, double-blinded fashion. RESULTS: We included 32 otolaryngology residency programs representing 249 residents in this analysis. Graduates published a mean of 1.3 (SD = 2.7) articles before residency, 3.5 (SD = 4.3) during residency, and 5.3 (SD = 9.3) after residency. Residents who pursued a fellowship had more total publications (t247 = -6.1, P < .001) and more first author publications (t247 = -5.4, P < .001) than residents without fellowship training. Graduates who chose a career in academic medicine had a higher number of mean total publications (t247 = -8.2, P < .001) and first author publications (t247 = -7.9, P < .001) than those who were not in academic medicine. There was a high positive correlation between residency program size and publications during residency (r = 0.76). CONCLUSION: Research productivity correlated with a number of characteristics such as future fellowship training, the pursuit of an academic career, and overall h-index in this study.

Bilateral Ear Canal Cholesteatoma with Underlying Type I First Branchial Cleft Anomalies.

OBJECTIVES:: To describe a case of bilateral ear canal cholesteatomas in the setting of underlying first branchial cleft cyst anomalies and to review the pathophysiology underlying the development of external auditory canal cholesteatomas from branchial cleft cyst abnormalities. METHODS AND RESULTS:: We present a case study of a 61-year-old man who presented with chronic right-sided hearing loss and left-sided postauricular drainage. Clinical evaluation, radiographic work-up, and pathologic analysis confirmed a diagnosis of bilateral ear canal cholesteatoma in the setting of underlying first branchial cleft cyst anomalies. The patient's clinical course, surgical treatment, and management considerations are discussed here. CONCLUSION:: Ear canal cholesteatoma represents a rare clinical disease entity deserving a thorough initial assessment. Careful consideration of underlying diseases that result in chronic inflammation, such as branchial cleft lesions, should be included in the differential diagnosis of idiopathic canal cholesteatoma in the absence of prior otologic surgery or trauma.

Adenomatous Neuroendocrine Tumors of the Middle Ear: A Multi-institutional Investigation of 32 Cases and Development of a Staging System.

OBJECTIVE: To date, less than 150 cases of middle ear adenomatous neuroendocrine tumors (MEANTs) have been reported in the English literature. The objective of this study was to provide a contemporary analysis of these rare lesions and develop a consensus-driven staging system. STUDY DESIGN: Multi-institutional retrospective histopathologic, radiologic, and clinical review. SETTING: Six tertiary referral centers. PATIENTS: Thirty-two patients with pathologically confirmed MEANT. INTERVENTION: Surgical resection, adjuvant therapy. MAIN OUTCOME MEASURES: Clinical manifestations, outcomes, staging system. RESULTS: Patients commonly presented with progressive conductive or mixed hearing loss (90%), aural fullness (50%), and tonal tinnitus (46%). Pulsatile tinnitus (16%), carcinoid syndrome (4%), and facial nerve paresis (4%) were less commonly observed. MEANTs frequently mimicked temporal bone paraganglioma (31%) and cholesteatoma (15%) at presentation. According to a novel T/N/M/S staging system (S = secretory tumor) proposed herein, there were 6 (19%) T1, 19 (59%) T2, and 7 (22%) T3 MEANTs. T3 tumors were significantly more likely to undergo subtotal or near total resection compared with lower staged tumors secondary to adherence to critical neurovascular structures such as the petrous internal carotid artery and facial nerve (p = 0.027). Patients with T3 MEANTs were more likely to experience multiple recurrences, require adjuvant therapy with a somatostatin analogue, or develop permanent facial nerve paresis compared with lower staged tumors. At last follow up, no patients with T1 MEANTs had developed recurrence, whereas 37% (7/19) of patients with T2 MEANT and 57% (4/7) of patients with T3 MEANT experienced either disease recurrence after gross total resection (GTR) or regrowth of known residual tumor requiring additional surgery at a median duration of 72 months (95% CI, 24-84). CONCLUSIONS: Patients with MEANTs can present with nonspecific symptomatology that overlaps with more commonly encountered middle ear lesions. MEANT exhibits a proclivity for recurrence according to T-stage and long-term clinical follow up is necessary, particularly for advanced stage tumors.

Association Between Patient Review of Systems Score and Somatization.

Importance: Somatization is a condition in which psychological distress is manifested by medically unexplained symptoms, and it is prevalent in all medical specialties, including otolaryngology. Recognition of somatization can be difficult, and there are limited methods available. Objectives: To determine whether patients with somatization respond differently to the review of systems (ROS) portion of the patient interview and whether the ROS can be used to identify patients with somatization. Design, Setting, and Participants: A retrospective review of medical records of 2120 consecutive consultations of English- or Spanish-speaking patients aged 18 to 89 years who presented to the otolaryngology clinic from January 1, 2014, to November 10, 2015, was conducted to compare how the ROS of patients with chief complaints associated with somatization (group B: globus sensation, dizziness, and tinnitus) differs from those with symptoms more often associated with objective findings (group A: nasal obstruction, hoarseness, and hearing loss); a total of 605 patients were included. Objective clinical findings after physical examination and related testing were reviewed and classified as either significant, marginal, or absent. Current or past psychiatric comorbidities were also examined. Main Outcomes and Measures: Number of affirmative responses on a standardized, 69-point ROS was recorded as a ROS score (ROSS). Objective clinical findings, symptoms, and psychiatric comorbidities were recorded. Results: Of the 605 patients included in the analysis, 346 (57.2%) were women, and the mean (SD) age was 51.6 (15.7) years. Among patients with medically unexplained symptoms (median, 11; range, 0-39), the ROSS was higher compared with those with objective clinical findings (median, 6; range, 0-31) (median difference, 4; 95% CI, 3 to 6). Group A (hoarseness, nasal obstruction, and hearing loss: median ROSS, 6, range, 0-41) exhibited lower ROSS than group B (dizziness, globus sensation, and tinnitus: median ROSS, 9; range, 0-39) (median difference, -2; 95% CI -3 to -1). Psychiatric comorbidity (median, 10; range, 0-41) was associated with higher ROSS than patients without psychiatric comorbidity (median, 5.5; range, 0 to 36) (median difference, 5; 95% CI, 3 to 6). Conclusions and Relevance: The manner in which patients respond to a standardized ROS differs in those with medically unexplained symptoms and in those with psychiatric disease. The ROS offers information beyond the actual systems review, and may be useful in the identification of somatization.

Otolaryngology Education: Recent Trends in Publication.

Objectives (1) Evaluate peer-reviewed publications regarding education in otolaryngology since 2000. (2) Analyze publication trends as compared with overall otolaryngology publications. Study Design Bibliometric analysis. Setting Academic medical center. Subjects and Methods A search for articles regarding education in otolaryngology from 2000 to 2015 was performed with MEDLINE and EMBASE databases, yielding 1220 articles; 362 relevant publications were categorized by topic, subspecialty, subject, article type, and funding source. Impact factors for each journal by year were obtained, and trends of each category over time were analyzed. These were then compared with publication numbers and impact factors for all otolaryngology journals. Results From 2000 to 2015, publications in otolaryngology education increased more rapidly than the field of otolaryngology overall. The most published topics included operative skills training, surgical simulation, and professionalism/career development. Recently there has been a decline in publications related to residency administration and duty hours relative to other topics. Only 12.2% of publications reported a funding source, and only 12.2% of studies were controlled. Conclusion Recent trends in otolaryngology literature reflect an increasing focus on education; however, this work is underfunded and often lacks high-quality evidence.

Identification of important positions within miRNAs by integrating sequential and structural features.

MicroRNA(miRNA) is a small, single stranded non-coding RNA which plays an important regulatory role in gene expression. Additionally, miRNAs perform crucial functions in a wide range of biological processes. These functions may be exploited for miRNA-mediated regulation of protein-protein interaction and thus protein function. Many computational methods have been developed to predict the miRNA targets and to explore the regulatory mechanism between miRNA and protein. However, the efforts to investigate important positions within miRNAs are not comprehensive. This paper presents a framework to identify important positions using collision entropy. The information of contained in the sequence and secondary structure of miRNAs is considered. Further, the single base collision entropy and the adjacent base related collision entropy are integrated to measure the importance of miRNA position. Two thresholds are employed to select those positions with more biological meaning. A dataset of Drosophila melanogaster is used in the experiments. The results demonstrate that our approach can find interesting and important positions within miRNAs and may lead to a better understanding of miRNA biogenesis and function.

Inhibition of K+ currents in type I vestibular hair cells by gentamicin and neomycin.

Significant ototoxicity limits the use of aminoglycoside (AG) antibiotics. Several mechanisms may contribute to the death of both auditory and vestibular hair cells. In this study the effects of gentamicin and neomycin on K(+) currents in mature and early postnatal type I vestibular hair cells (HCI) were tested directly. The whole-cell patch clamp technique was used to assess the effects of AG and KCNQ channel modulators on K(+) currents (IK) in HCI acutely isolated from gerbil semicircular canals. Extracellular neomycin (1 mM) rapidly reduced peak outward IK by 16 ± 4% (n = 9) in mature HCI (postnatal days, P, 25-66). Gentamicin (5 mM) reduced outward IK by 16 ± 3% (n = 8). A similar reduction in outward current was seen in immature HCI (P5-9) that lacked the low-voltage-activated component of IK observed in mature cells. Intracellular application of gentamicin and neomycin also reduced IK in mature HCI. Modulators of KCNQ channels were used to probe KCNQ channel involvement. The selective KCNQ antagonist XE991 did not reduce IK and the neomycin-induced reduction in IK was not reversed by the KCNQ agonist flupirtine. Application of intracellular poly-D-lysine to sequester PIP2 did not reduce IK. Application of the K(+) channel blocker 4-aminopyridine (4-AP) strongly reduced IK, and extracellular AG in the presence of 4-AP gave no further inhibition of IK. In summary, AG significantly reduce the 4-AP-sensitive IK in early postnatal and mature HCI. K(+) current inhibition differs from that seen in outer hair cells, since it does not appear to involve PIP2 sequestration or KCNQ channels.

K+ currents in isolated vestibular afferent calyx terminals.

Vestibular hair cells transduce mechanical displacements of their hair bundles into an electrical receptor potential which modulates transmitter release and subsequent action potential firing in afferent neurons. To probe ionic mechanisms underlying sensory coding in vestibular calyces, we used the whole-cell patch-clamp technique to record action potentials and K(+) currents from afferent calyx terminals isolated from the semicircular canals of Mongolian gerbils. Calyx terminals showed minimal current at the mean zero-current potential (-60 mV), but two types of outward K(+) currents were identified at potentials above -50 mV. The first current was a rapidly activating and inactivating K(+) current that was blocked by 4-aminopyridine (4-AP, 2.5 mM) and BDS-I (up to 250 nM). The time constant for activation of this current decreased with membrane depolarization to a minimum value of approximately 1 ms. The 4-AP-sensitive current showed steady-state inactivation with a half-inactivation of approximately -70 mV. A second, more slowly activating current (activation time constant was 8.5 +/- 0.7 ms at -8 mV) was sensitive to TEA (30 mM). The TEA-sensitive current also showed steady-state inactivation with a half-inactivation of -95.4 +/- 1.4 mV, following 500-ms duration conditioning pulses. A combination of 4-AP and TEA blocked approximately 90% of the total outward current. In current clamp, single Na(+)-dependent action potentials were evoked following hyperpolarization to potentials more negative than the resting potential. 4-AP application increased action potential width, whereas TEA both increased the width and greatly reduced repolarization of the action potential.

Exostoses of the external auditory canal in white-water kayakers.

OBJECTIVES/HYPOTHESIS: Exostoses of the external auditory canal are benign bony tumors associated with frequent cold-water exposure. Obstruction may lead to conductive hearing loss and recurrent otitis externa, requiring surgical correction when symptoms become intolerable. This study aimed to characterize the prevalence of exostoses in white-water kayakers and identify associated risk factors and protective measures. STUDY DESIGN: Cross-sectional. METHODS: Six hundred eleven white-water kayakers from across the United States were included in the study. Percent occlusion was graded as minimal (<25%), moderate (25%-75%) or severe (>75%). Subjects completed a survey of risk factors and protective measures. Kruskal-Wallis and chi(2) tests were performed to determine significant associations with percent occlusion. A multivariate proportional odds regression model was fit to adjust for confounding between the variables. RESULTS: The prevalence of exostoses in kayakers was 79% (482/611); 13% (78/611) had >or=75% occlusion. Percent occlusion was associated with total years kayaked (P < .001), frequency >or=1 day/week (P < .001), male gender (P < .001), and increasing age (P = .005), although frequency, gender, and age were confounded by total years. Styles that involve repeated submersion were also associated with greater occlusion (freestyle, P = .036; squirt, P = .016). Subjects who used earplugs for a greater proportion of their kayaking career were less likely to have exostoses (P < .001). When adjusted for confounding, only total years (P = .0003) and age (P = .0027) remained significant. CONCLUSIONS: Kayakers are the first inland population to experience exostoses at the rates seen in coastal populations (e.g., surfers). When used long-term, earplugs may be protective.

Insights into bacterial genome composition through variable target GC content profiling.

This study presents a new computational method for guanine (G) and cytosine (C), or GC, content profiling based on the idea of multiple resolution sampling (MRS). The benefit of our new approach over existing techniques follows from its ability to locate significant regions without prior knowledge of the sequence, nor the features being sought. The use of MRS has provided novel insights into bacterial genome composition. Key findings include those that are related to the core composition of bacterial genomes, to the identification of large genomic islands (in Enterobacterial genomes), and to the identification of surface protein determinants in human pathogenic organisms (e.g., Staphylococcus genomes). We observed that bacterial surface binding proteins maintain abnormal GC content, potentially pointing to a viral origin. This study has demonstrated that GC content holds a high informational worth and hints at many underlying evolutionary processes. For online Supplementary Material, see www.liebertonline.com .

Bacterial genomic G+C composition-eliciting environmental adaptation.

Bacterial genomes reflect their adaptation strategies through nucleotide usage trends found in their chromosome composition. Bacteria, unlike eukaryotes contain a wide range of genomic G+C. This wide variability may be viewed as a response to environmental adaptation. Two overarching trends are observed across bacterial genomes, the first, correlates genomic G+C to environmental niches and lifestyle, while the other utilizees intra-genomic G+C incongruence to delineate horizontally transferred material. In this review, we focus on the influence of several properties including biochemical, genetic flows, selection biases, and the biochemical-energetic properties shaping genome composition. Outcomes indicate a trend toward high G+C and larger genomes in free-living organisms, as a result of more complex and varied environments (higher chance for horizontal gene transfer). Conversely, nutrient limiting and nutrient poor environments dictate smaller genomes of low GC in attempts to conserve replication expense. Varied processes including translesion repair mechanisms, phage insertion and cytosine degradation has been shown to introduce higher AT in genomic sequences. We conclude the review with an analysis of current bioinformatics tools seeking to elicit compositional variances and highlight the practical implications when using such techniques.