Vaginal spindle cell epithelioma: A first complete MRI and histopathologic description.

Spindle cell epithelioma of the vagina is a benign entity with fewer than sixty cases described in the literature, and only two with limited imaging findings, since the early 1950s. Early pathology literature suggested the lesions were mixed tumors of myoepithelial origin, but subsequent studies have found relatively few immunohistochemical characteristics in common with other mixed cell tumors. More recently, Mullerian, urogenital sinus epithelial, and pluripotential cell origins have been proposed. Given lesion rarity and a typical lack of imaging before excision, the imaging appearance of vaginal spindle cell epitheliomas has not been fully described in the radiology literature, and without comprehensive pathology correlation. The authors describe a case of spindle cell epithelioma in a 54-year-old woman which was incidentally discovered on MRI performed for uterine fibroid embolization planning. Pathology and immunohistochemistry confirmed the diagnosis.

Jaw Rotation in Dysarthria Measured With a Single Electromagnetic Articulography Sensor.

PURPOSE: This study evaluated a novel method for characterizing jaw rotation using orientation data from a single electromagnetic articulography sensor. This method was optimized for clinical application, and a preliminary examination of clinical feasibility and value was undertaken. METHOD: The computational adequacy of the single-sensor orientation method was evaluated through comparisons of jaw-rotation histories calculated from dual-sensor positional data for 16 typical talkers. The clinical feasibility and potential value of single-sensor jaw rotation were assessed through comparisons of 7 talkers with dysarthria and 19 typical talkers in connected speech. RESULTS: The single-sensor orientation method allowed faster and safer participant preparation, required lower data-acquisition costs, and generated less high-frequency artifact than the dual-sensor positional approach. All talkers with dysarthria, regardless of severity, demonstrated jaw-rotation histories with more numerous changes in movement direction and reduced smoothness compared with typical talkers. CONCLUSIONS: Results suggest that the single-sensor orientation method for calculating jaw rotation during speech is clinically feasible. Given the preliminary nature of this study and the small participant pool, the clinical value of such measures remains an open question. Further work must address the potential confound of reduced speaking rate on movement smoothness.

Vocal classification of vocalizations of a pair of Asian small-clawed otters to determine stress.

Asian Small-Clawed Otters (Aonyx cinerea) are a small, protected but threatened species living in freshwater. They are gregarious and live in monogamous pairs for their lifetimes, communicating via scent and acoustic vocalizations. This study utilized a hidden Markov model (HMM) to classify stress versus non-stress calls from a sibling pair under professional care. Vocalizations were expertly annotated by keepers into seven contextual categories. Four of these-aggression, separation anxiety, pain, and prefeeding-were identified as stressful contexts, and three of them-feeding, training, and play-were identified as non-stressful contexts. The vocalizations were segmented, manually categorized into broad vocal type call types, and analyzed to determine signal to noise ratios. From this information, vocalizations from the most common contextual categories were used to implement HMM-based automatic classification experiments, which included individual identification, stress vs non-stress, and individual context classification. Results indicate that both individual identity and stress vs non-stress were distinguishable, with accuracies above 90%, but that individual contexts within the stress category were not easily separable.

Women seeking second opinion for symptomatic uterine leiomyoma: role of comprehensive fibroid center.

OBJECTIVE: The objective of the study was to describe our early experience with a comprehensive uterine fibroid center and report our results in women seeking a second opinion for management of symptomatic uterine leiomyoma. METHODS: We performed a HIPAA-complaint, IRB-approved retrospective study of women seeking second opinion for management of uterine fibroids at our multidisciplinary fibroid treatment center in a tertiary care facility from July 2008 to August 2011. After a review of patients' history, physical examination, and magnetic resonance imaging (MRI) findings, treatment options were discussed which included conservative management, uterine-preserving options, and hysterectomy. We performed Fisher's exact test for categorical variables between the cohort that did or did not undergo a uterine-preserving treatment. Differences were considered significant at p < 0.05. RESULTS: The mean age of the 205 patient study cohort was 43.8 years (SD 7.5). One hundred sixty-two (79.0%) patients had no prior therapy. Based on MRI, one or more fibroids were detected in 178/205 (86.8%), adenomyosis in 8/205 (3.9%), and a combination of fibroid and nonfibroid condition (i.e., adenomyosis, endometrial polyp) in 18/205 (8.8%). In those who desired to transition their care to our institution (n = 109), 85 patients underwent 90 interventions: 39 MRgFUS (magnetic resonance-guided high-intensity focused ultrasound surgery), 14 UAE (uterine artery embolization), 25 myomectomies, 8 hysterectomies, 3 polypectomies, and 1 endometrial ablation. Five patients had two procedures. Intramural and subserosal fibroids were most commonly treated with MRgFUS followed by myomectomy and then UAE; in contrast, pedunculated fibroids were frequently managed with myomectomy. CONCLUSIONS: Multidisciplinary fibroid evaluation may facilitate the increase use of less invasive options over hysterectomy for symptomatic fibroid treatment.

Evaluation of the importance of time-frequency contributions to speech intelligibility in noise.

Recent studies on binary masking techniques make the assumption that each time-frequency (T-F) unit contributes an equal amount to the overall intelligibility of speech. The present study demonstrated that the importance of each T-F unit to speech intelligibility varies in accordance with speech content. Specifically, T-F units are categorized into two classes, speech-present T-F units and speech-absent T-F units. Results indicate that the importance of each speech-present T-F unit to speech intelligibility is highly related to the loudness of its target component, while the importance of each speech-absent T-F unit varies according to the loudness of its masker component. Two types of mask errors are also considered, which include miss and false alarm errors. Consistent with previous work, false alarm errors are shown to be more harmful to speech intelligibility than miss errors when the mixture signal-to-noise ratio (SNR) is below 0 dB. However, the relative importance between the two types of error is conditioned on the SNR level of the input speech signal. Based on these observations, a mask-based objective measure, the loudness weighted hit-false, is proposed for predicting speech intelligibility. The proposed objective measure shows significantly higher correlation with intelligibility compared to two existing mask-based objective measures.

Discrimination of individual tigers (Panthera tigris) from long distance roars.

This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha's Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, represented by the number of sequential states in the HMM. Results indicate that the temporal pattern of the vocalization is the most significant factor in accurate discrimination. Overall baseline discrimination accuracy for this data set is about 70% using high level features without complex spectral or temporal models. Accuracy increases to about 80% when more complex spectral models (multiple mixture GMMs) are incorporated, and increases to a final accuracy of 90% when more detailed temporal models (10-state HMMs) are used. Classification accuracy is stable across a relatively wide range of configurations in terms of spectral and temporal model resolution.

Noise impacts from professional dog grooming forced-air dryers.

This study was designed to measure the sound output of four commonly used brands of forced-air dryers used by dog groomers in the United States. Many dog groomers have questions about the effect of this exposure on their hearing, as well as on the hearing of the dogs that are being groomed. Readings taken from each dryer at 1 meter (the likely distance of the dryer from the groomer and the dog) showed average levels ranging from 105.5 to 108.3 dB SPL or 94.8 to 108.0 dBA. Using the 90 dBA criterion required by the US Occupational Safety and Health Administration, dog groomers/bathers are at risk if exposure to the lowest intensity dryer (94.8 dBA) exceeds 4 hours per day. If the more stringent 85 dBA criterion and 3 dB tradeoff is applied, less than one hour of exposure is permissible in an 8 hour day. Cautions are recommended for any persons exposed to noise from forced-air dryers.

An institutional perspective on the impact of recent antibiotic exposure on length of stay and hospital costs for patients with gram-negative sepsis.

BACKGROUND: Prior antibiotic exposure has been associated with the emergence of antibiotic resistance in subsequent bacterial infections, whose outcomes are typically worse than similar infections with more antibiotic susceptible infections. The influence of prior antibiotic exposure on hospital length of stay (LOS) and costs in patients with severe sepsis or septic shock attributed to Gram-negative bacteremia has not been previously examined. METHODS: A retrospective cohort study of hospitalized patients (January 2002-December 2007) was performed at Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. Patients with Gram-negative bacteremia complicated by severe sepsis or septic shock had data abstraction from computerized medical records. We examined a consecutive cohort of 754 subjects (mean age 59.3 ± 16.3 yrs, mean APACHE II 23.7 ± 6.7). RESULTS: Escherichia coli (30.8%), Klebsiella pneumoniae (23.2%), and Pseudomonas aeruginosa (17.6%) were the most common organisms isolated from blood cultures. 310 patients (41.1%) had exposure to antimicrobial agents in the previous 90 days. Patients with recent antibiotic exposure had greater inappropriate initial antimicrobial therapy (45.4% v. 21.2%; p < 0.001) and hospital mortality (51.3% v. 34.0%; p < 0.001) compared to patients without recent antibiotic exposure. The unadjusted median LOS (25th percentile, 75th percentile) following sepsis onset in patients with prior antimicrobial exposure was 13.0 days (5.0 days, 24.0 days) compared to 8.0 days (5.0 days, 14.0 days) in those without prior antimicrobial exposure (p < 0.001). In a Cox model controlling for multiple confounders, prior antibiotic exposure independently correlated with remaining hospitalized (Adjusted hazard ratio: 1.473, 95% CI: 1.297-1.672, p < 0.001). Adjusting for potential confounders indicated that prior antibiotic exposure independently increased median attributable LOS by 5.0 days. Similarly, total hospital costs following sepsis onset was significantly greater among patients with prior antimicrobial exposure (median values: $94,737 v. $21,329; p < 0.001). CONCLUSIONS: Recent antibiotic exposure is associated with increased LOS and hospital costs in Gram-negative bacteremia complicated by severe sepsis or septic shock. Clinicians and hospital administrators should consider the potential impact of recent antibiotic exposure when formulating empiric treatment decisions for patients with serious infections attributed to Gram-negative bacteria.

Evaluation of a simplified N-acetylcysteine dosing regimen for the treatment of acetaminophen toxicity.

BACKGROUND: Acetaminophen overdose is the most common pharmaceutical poisoning in the US. The labeled dosing regimen for Acetadote, the only intravenous N-acetylcysteine (IV-NAC) product approved by the Food and Drug Administration (FDA) for treatment of acetaminophen toxicity, is a complex 3-step process that produces frequent medication errors. We have been using an off-label, uncomplicated dosing regimen consisting of a standard preparation of IV-NAC 30 g in 1 L of 5% dextrose in water, with a 150-mg/kg loading dose administered over 1 hour followed by an infusion of 14 mg/kg/h for 20 hours. OBJECTIVE: To evaluate the frequency of medication errors, resolution of hepatotoxicity, and tolerability of the protocol used in our institution for treatment of acetaminophen toxicity. METHODS: This single-center, retrospective chart review evaluated patients receiving IV-NAC for acetaminophen toxicity from August 2006 to August 2008. Charts were reviewed for prescribing practices, dosing errors, and clinical outcomes. RESULTS: Among 70 patients who met inclusion criteria, 35 medication errors occurred, including 22 administration errors and 13 protocol initiation errors. The frequency of administration errors was 13.5 errors per 100 administration interventions. Loading dose errors were most common with 11 rate-related and 8 dose-related errors. Interruptions longer than 60 minutes occurred in only 3 patients. No adverse outcomes were associated with medication errors. The mean (SD) duration of therapy was 25.6 hours (n = 60 pts. [17.8], range 1-76.5), and mean length of stay was 2.99 days ([3.82], range 0.1-25.7). All patients with hepatotoxicity (aspartate aminotransferase >1000 units/L) due to acute acetaminophen toxicity had resolution of the toxicity and were successfully discharged. CONCLUSIONS: This single intravenous bag protocol is effective and well tolerated, and there is infrequent interruption of therapy. The overall rate of administration errors is similar to that in reports on the FDA regimen; thus, our protocol may be an acceptable alternative.

Impact of previous antibiotic therapy on outcome of Gram-negative severe sepsis.

OBJECTIVE: To determine whether exposure to antimicrobial agents in the previous 90 days resulted in decreased bacterial susceptibility and increased hospital mortality in patients with severe sepsis or septic shock attributed to Gram-negative bacteremia. DESIGN: A retrospective cohort study of hospitalized patients (January 2002 to December 2007). SETTING: Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. PATIENTS: Seven hundred fifty-four consecutive patients with Gram-negative bacteremia complicated by severe sepsis or septic shock. INTERVENTIONS: Data abstraction from computerized medical records. MEASUREMENTS AND MAIN RESULTS: Escherichia coli (30.8%), Klebsiella pneumoniae (23.2%), and Pseudomonas aeruginosa (17.6%) were the most common isolates from blood cultures. Three hundred ten patients (41.1%) had recent antibiotic exposure. Cefepime was the most common agent with previous exposure (50.0%) followed by ciprofloxacin (32.6%) and imipenem or meropenem (28.7%). Patients with prior antibiotic exposure had significantly higher rates of resistance to cefepime (29.0% vs. 7.0%), piperacillin/tazobactam (31.9% vs. 11.5%), carbapenems (20.0% vs. 2.5%), ciprofloxacin (39.7% vs. 17.6%), and gentamicin (26.1% vs. 7.9%) (p < .001 for all comparisons). Patients with recent antibiotic exposure had greater inappropriate initial antimicrobial therapy (45.4% vs. 21.2%; p < .001) and hospital mortality (51.3% vs. 34.0%; p < .001) compared with patients without recent antibiotic exposure. Multivariate logistic regression analysis demonstrated that recent antibiotic exposure was independently associated with hospital mortality (adjusted odds ratio, 1.70; 95% confidence interval, 1.41-2.06; p = .005). Other variables independently associated with hospital mortality included use of vasopressors, infection resulting from P. aeruginosa, inappropriate initial antimicrobial therapy, increasing Acute Physiology and Chronic Health Evaluation II scores, and the number of acquired organ failures. CONCLUSIONS: Recent antibiotic exposure is associated with increased hospital mortality in Gram-negative bacteremia complicated by severe sepsis or septic shock. Clinicians caring for patients with severe sepsis or septic shock should consider recent antibiotic exposure when formulating empiric antimicrobial regimens for suspected Gram-negative bacterial infection.

Acoustic censusing using automatic vocalization classification and identity recognition.

This paper presents an advanced method to acoustically assess animal abundance. The framework combines supervised classification (song-type and individual identity recognition), unsupervised classification (individual identity clustering), and the mark-recapture model of abundance estimation. The underlying algorithm is based on clustering using hidden Markov models (HMMs) and Gaussian mixture models (GMMs) similar to methods used in the speech recognition community for tasks such as speaker identification and clustering. Initial experiments using a Norwegian ortolan bunting (Emberiza hortulana) data set show the feasibility and effectiveness of the approach. Individually distinct acoustic features have been observed in a wide range of animal species, and this combined with the widespread success of speaker identification and verification methods for human speech suggests that robust automatic identification of individuals from their vocalizations is attainable. Only a few studies, however, have yet attempted to use individual acoustic distinctiveness to directly assess population density and structure. The approach introduced here offers a direct mechanism for using individual vocal variability to create simpler and more accurate population assessment tools in vocally active species.

The Sickle Cell Sabbath: a community program increases first-time blood donors in the African American faith community.

BACKGROUND: Blood transfusion therapy is an established treatment for primary and secondary prevention of strokes in children with sickle cell disease (SCD), a disease that predominantly affects African Americans. African American blood donors are more likely to have compatible minor red blood cell antigens for children with SCD who routinely receive transfusions. This study tested the hypothesis that when informed at church about the importance of blood donation, African Americans will have a higher than expected rate of first-time blood donation compared to the general population. STUDY DESIGN AND METHODS: The Sickle Cell Sabbath Program was developed to increase awareness about SCD and the importance of blood donations within the African American faith community. Church involvement in the program included a 5-minute scripted educational session about SCD that included the importance of blood donations followed by a blood donor drive that was hosted by the church. RESULTS: Thirteen African American churches sponsored 34 blood drives from 2003 through 2006. Each church sponsored at least two blood drives. Approximately 1200 donors participated in the sickle cell blood drives. The majority of the donors were first-time donors and represented a greater than expected first-time donor rate when compared to first-time donors in the metropolitan St Louis area, 60 percent (422 of 699) and 12.2 percent (21,516 of 175,818), respectively (p = 0.001). CONCLUSION: An educational program that engages the African American faith community more than quadruples the rate of expected first-time blood donors when compared to the general community over this 4-year period.

Perceptually motivated wavelet packet transform for bioacoustic signal enhancement.

A significant and often unavoidable problem in bioacoustic signal processing is the presence of background noise due to an adverse recording environment. This paper proposes a new bioacoustic signal enhancement technique which can be used on a wide range of species. The technique is based on a perceptually scaled wavelet packet decomposition using a species-specific Greenwood scale function. Spectral estimation techniques, similar to those used for human speech enhancement, are used for estimation of clean signal wavelet coefficients under an additive noise model. The new approach is compared to several other techniques, including basic bandpass filtering as well as classical speech enhancement methods such as spectral subtraction, Wiener filtering, and Ephraim-Malah filtering. Vocalizations recorded from several species are used for evaluation, including the ortolan bunting (Emberiza hortulana), rhesus monkey (Macaca mulatta), and humpback whale (Megaptera novaeanglia), with both additive white Gaussian noise and environment recording noise added across a range of signal-to-noise ratios (SNRs). Results, measured by both SNR and segmental SNR of the enhanced wave forms, indicate that the proposed method outperforms other approaches for a wide range of noise conditions.

Acoustic model adaptation for ortolan bunting (Emberiza hortulana L.) song-type classification.

Automatic systems for vocalization classification often require fairly large amounts of data on which to train models. However, animal vocalization data collection and transcription is a difficult and time-consuming task, so that it is expensive to create large data sets. One natural solution to this problem is the use of acoustic adaptation methods. Such methods, common in human speech recognition systems, create initial models trained on speaker independent data, then use small amounts of adaptation data to build individual-specific models. Since, as in human speech, individual vocal variability is a significant source of variation in bioacoustic data, acoustic model adaptation is naturally suited to classification in this domain as well. To demonstrate and evaluate the effectiveness of this approach, this paper presents the application of maximum likelihood linear regression adaptation to ortolan bunting (Emberiza hortulana L.) song-type classification. Classification accuracies for the adapted system are computed as a function of the amount of adaptation data and compared to caller-independent and caller-dependent systems. The experimental results indicate that given the same amount of data, supervised adaptation significantly outperforms both caller-independent and caller-dependent systems.

Generalized perceptual linear prediction features for animal vocalization analysis.

A new feature extraction model, generalized perceptual linear prediction (gPLP), is developed to calculate a set of perceptually relevant features for digital signal analysis of animal vocalizations. The gPLP model is a generalized adaptation of the perceptual linear prediction model, popular in human speech processing, which incorporates perceptual information such as frequency warping and equal loudness normalization into the feature extraction process. Since such perceptual information is available for a number of animal species, this new approach integrates that information into a generalized model to extract perceptually relevant features for a particular species. To illustrate, qualitative and quantitative comparisons are made between the species-specific model, generalized perceptual linear prediction (gPLP), and the original PLP model using a set of vocalizations collected from captive African elephants (Loxodonta africana) and wild beluga whales (Delphinapterus leucas). The models that incorporate perceptional information outperform the original human-based models in both visualization and classification tasks.

Position, direction of movement, and speed tuning of cerebellar Purkinje cells during circular manual tracking in monkey.

The cerebellum plays an essential role in pursuit tracking with the eye and with the hand. During smooth pursuit eye movements, both tracking position and velocity are signaled by Purkinje cells. Purkinje cell simple spike discharge is also modulated by direction and speed during linear manual tracking. This study evaluated how all three parameters, position, movement direction, and speed, are signaled in the simple spike discharge of Purkinje cells during circular manual tracking. Three rhesus monkeys intercepted and then tracked a target moving in a circle in both counterclockwise and clockwise directions across a range of constant target speeds. Two sets of analyses of the simple spike firing of 97 Purkinje cells examined the effects of position, movement direction, and speed. The first approach was the incremental improvement of regression models, initially modeling a pure position dependence, then incorporating movement direction, and finally incorporating speed dependence. The second was a model-independent approach, without any explicit assumptions about the character of the directional tuning or speed effects. Both analyses revealed the same three results: (1) Purkinje cell discharge is spatially tuned, to both the position and direction of movement, and (2) this spatial tuning is not altered by the speed, except (3) the speed scales the average firing and/or depth of modulation. The results suggest that the population of Purkinje cells forms a representation of the entire position-direction space of arm movements, and that the speed modulates the scale of that representation. This speed scaling provides insights into the cerebellar processing of movement-related timing.

Automatic classification and speaker identification of African elephant (Loxodonta africana) vocalizations.

A hidden Markov model (HMM) system is presented for automatically classifying African elephant vocalizations. The development of the system is motivated by successful models from human speech analysis and recognition. Classification features include frequency-shifted Mel-frequency cepstral coefficients (MFCCs) and log energy, spectrally motivated features which are commonly used in human speech processing. Experiments, including vocalization type classification and speaker identification, are performed on vocalizations collected from captive elephants in a naturalistic environment. The system classified vocalizations with accuracies of 94.3% and 82.5% for type classification and speaker identification classification experiments, respectively. Classification accuracy, statistical significance tests on the model parameters, and qualitative analysis support the effectiveness and robustness of this approach for vocalization analysis in nonhuman species.

What do complex spikes signal about limb movements?

Deciphering the information or signals carried by the complex spike discharge of Purkinje cells has proven to be problematic, primarily because of low frequency discharge and lack of adequate analytical techniques. This problem is particularly acute for studies of limb movements. To this end the relationship of cerebellar Purkinje cell complex spike discharge to direction and speed were studied in a manual-tracking task. Two monkeys were trained to pursue track targets moving in one of eight directions and at one of four speeds. An analysis based on Poisson regression modeling fitted the complex spike counts during single movement trials to target direction and/or speed. Using single trial data, the Poisson modeling demonstrated that the complex spike discharge for a majority of the Purkinje cells was significantly fit to tracking direction and speed. A second analysis based on the directional distribution of position and speed errors and a Poisson regression model of complex spike discharge to tracking position and speed errors found little relationship to movement error. Comparison of the preferred direction of the complex spike discharge with that of the simple spike activity revealed a reciprocal relationship for many cells. Thus, the complex spike discharge signals both tracking direction and speed but not movement errors. Furthermore, treating complex spike counts as a Poisson process provides a powerful tool for analyzing these events in single trials, without the need for extensive averaging.