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OBJECTIVES - We sought to validate the use of crowdsourced surgical video assessment in the evaluation of urology residents performing flexible ureteroscopic laser lithotripsy.
METHODS - We collected video feeds from 30 intrarenal ureteroscopic laser lithotripsy cases where residents, postgraduate year (PGY) two through six, handled the ureteroscope. The video feeds were annotated to represent overall performance and to contain parts of the procedure being scored. Videos were submitted to a commercially available surgical video evaluation platform (Crowd-Sourced Assessment of Technical Skills). We used a validated ureteroscopic laser lithotripsy global assessment tool that was modified to include only those domains that could be evaluated on the captured video. Videos were evaluated by crowd workers recruited using Amazon's Mechanical Turk platform as well as five endourology-trained experts. Mean scores were calculated and intraclass correlation coefficients (ICCs) were computed for the expert domain and total scores. ICCs were estimated using a linear mixed-effects model. Spearman rank correlation coefficients were calculated as a measure of the strength of the relationships between the crowd mean and expert average scores.
RESULTS - A total of 30 videos were reviewed 2488 times by 487 crowd workers and five expert endourologists. ICCs between expert raters were all below accepted levels of correlation (0.30), with the overall score having an ICC of <0.001. For individual domains, the crowd scores did not correlate with expert scores, except for the stone retrieval domain (0.60 p = 0.015). In addition, crowdsourced scores had a negative correlation with the PGY level (0.44, p = 0.019).
CONCLUSIONS - There is poor agreement between experts and poor correlation between expert and crowd scores when evaluating video feeds of ureteroscopic laser lithotripsy. The use of an intraoperative video of ureteroscopy with laser lithotripsy for assessment of resident trainee skills does not appear reliable. This is further supported by the lack of correlation between crowd scores and advancing PGY level.
Dravet syndrome, an early onset epileptic encephalopathy, is most often caused by de novo mutation of the neuronal voltage-gated sodium channel gene SCN1A. Mouse models with deletion of Scn1a recapitulate Dravet syndrome phenotypes, including spontaneous generalized tonic-clonic seizures, susceptibility to seizures induced by elevated body temperature, and elevated risk of sudden unexpected death in epilepsy. Importantly, the epilepsy phenotype of Dravet mouse models is highly strain-dependent, suggesting a strong influence of genetic modifiers. We previously identified Cacna1g, encoding the Cav3.1 subunit of the T-type calcium channel family, as an epilepsy modifier in the Scn2a transgenic epilepsy mouse model. In this study, we asked whether transgenic alteration of Cacna1g expression modifies severity of the Scn1a Dravet phenotype. Scn1a mice with decreased Cacna1g expression showed partial amelioration of disease phenotypes with improved survival and reduced spontaneous seizure frequency. However, reduced Cacna1g expression did not alter susceptibility to hyperthermia-induced seizures. Transgenic elevation of Cacna1g expression had no effect on the Scn1a epilepsy phenotype. These results provide support for Cacna1g as a genetic modifier in a mouse model of Dravet syndrome and suggest that Cav3.1 may be a potential molecular target for therapeutic intervention in patients.
Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.
OBJECTIVE - To evaluate the effect of video laryngoscopy on the rate of endotracheal intubation on first laryngoscopy attempt among critically ill adults.
DESIGN - A randomized, parallel-group, pragmatic trial of video compared with direct laryngoscopy for 150 adults undergoing endotracheal intubation by Pulmonary and Critical Care Medicine fellows.
SETTING - Medical ICU in a tertiary, academic medical center.
PATIENTS - Critically ill patients 18 years old or older.
INTERVENTIONS - Patients were randomized 1:1 to video or direct laryngoscopy for the first attempt at endotracheal intubation.
MEASUREMENTS AND MAIN RESULTS - Patients assigned to video (n = 74) and direct (n = 76) laryngoscopy were similar at baseline. Despite better glottic visualization with video laryngoscopy, there was no difference in the primary outcome of intubation on the first laryngoscopy attempt (video 68.9% vs direct 65.8%; p = 0.68) in unadjusted analyses or after adjustment for the operator's previous experience with the assigned device (odds ratio for video laryngoscopy on intubation on first attempt 2.02; 95% CI, 0.82-5.02, p = 0.12). Secondary outcomes of time to intubation, lowest arterial oxygen saturation, complications, and in-hospital mortality were not different between video and direct laryngoscopy.
CONCLUSIONS - In critically ill adults undergoing endotracheal intubation, video laryngoscopy improves glottic visualization but does not appear to increase procedural success or decrease complications.
PURPOSE - There is an ongoing need to develop assessments of spontaneous speech that focus on whether the child's utterances are comprehensible to listeners. This study sought to identify the attributes of a stable ratings-based measure of speech comprehensibility, which enabled examining the criterion-related validity of an orthography-based measure of the comprehensibility of conversational speech in students with Down syndrome.
METHOD - Participants were 10 elementary school students with Down syndrome and 4 unfamiliar adult raters. Averaged across-observer Likert ratings of speech comprehensibility were called a ratings-based measure of speech comprehensibility. The proportion of utterance attempts fully glossed constituted an orthography-based measure of speech comprehensibility.
RESULTS - Averaging across 4 raters on four 5-min segments produced a reliable (G = .83) ratings-based measure of speech comprehensibility. The ratings-based measure was strongly (r > .80) correlated with the orthography-based measure for both the same and different conversational samples.
CONCLUSION - Reliable and valid measures of speech comprehensibility are achievable with the resources available to many researchers and some clinicians.
Kinesin-8s are plus-end-directed motors that negatively regulate microtubule (MT) length. Well-characterized members of this subfamily (Kip3, Kif18A) exhibit two important properties: (i) They are "ultraprocessive," a feature enabled by a second MT-binding site that tethers the motors to a MT track, and (ii) they dissociate infrequently from the plus end. Together, these characteristics combined with their plus-end motility cause Kip3 and Kif18A to enrich preferentially at the plus ends of long MTs, promoting MT catastrophes or pausing. Kif18B, an understudied human kinesin-8, also limits MT growth during mitosis. In contrast to Kif18A and Kip3, localization of Kif18B to plus ends relies on binding to the plus-end tracking protein EB1, making the relationship between its potential plus-end-directed motility and plus-end accumulation unclear. Using single-molecule assays, we show that Kif18B is only modestly processive and that the motor switches frequently between directed and diffusive modes of motility. Diffusion is promoted by the tail domain, which also contains a second MT-binding site that decreases the off rate of the motor from the MT lattice. In cells, Kif18B concentrates at the extreme tip of a subset of MTs, superseding EB1. Our data demonstrate that kinesin-8 motors use diverse design principles to target MT plus ends, which likely target them to the plus ends of distinct MT subpopulations in the mitotic spindle.
Video-based eye tracking relies on locating pupil center to measure gaze positions. Although widely used, the technique is known to generate spurious gaze position shifts up to several degrees in visual angle because pupil centration can change without eye movement during pupil constriction or dilation. Since pupil size can fluctuate markedly from moment to moment, reflecting arousal state and cognitive processing during human behavioral and neuroimaging experiments, the pupil size artifact is prevalent and thus weakens the quality of the video-based eye tracking measurements reliant on small fixational eye movements. Moreover, the artifact may lead to erroneous conclusions if the spurious signal is taken as an actual eye movement. Here, we measured pupil size and gaze position from 23 human observers performing a fixation task and examined the relationship between these two measures. Results disclosed that the pupils contracted as fixation was prolonged, at both small (<16s) and large (∼4min) time scales, and these pupil contractions were accompanied by systematic errors in gaze position estimation, in both the ellipse and the centroid methods of pupil tracking. When pupil size was regressed out, the accuracy and reliability of gaze position measurements were substantially improved, enabling differentiation of 0.1° difference in eye position. We confirmed the presence of systematic changes in pupil size, again at both small and large scales, and its tight relationship with gaze position estimates when observers were engaged in a demanding visual discrimination task.
Copyright © 2015 Elsevier Ltd. All rights reserved.
In brain tumor surgery, soft-tissue deformation, known as brain shift, introduces inaccuracies in the application of the preoperative surgical plan and impedes the advancement of image-guided surgical (IGS) systems. Considerable progress in using patient-specific biomechanical models to update the preoperative images intraoperatively has been made. These model-update methods rely on accurate intraoperative 3D brain surface displacements. In this work, we investigate and develop a fully automatic method to compute these 3D displacements for lengthy (~15 minutes) stereo-pair video sequences acquired during neurosurgery. The first part of the method finds homologous points temporally in the video and the second part computes the nonrigid transformation between these homologous points. Our results, based on parts of 2 clinical cases, show that this speedy and promising method can robustly provide 3D brain surface measurements for use with model-based updating frameworks.
Hemolymph circulation in insects is driven primarily by the contractile action of a dorsal vessel, which is divided into an abdominal heart and a thoracic aorta. As holometabolous insects, mosquitoes undergo striking morphological and physiological changes during metamorphosis. This study presents a comprehensive structural and functional analysis of the larval and adult dorsal vessel in the malaria mosquito Anopheles gambiae. Using intravital video imaging we show that, unlike the adult heart, the larval heart contracts exclusively in the anterograde direction and does not undergo heartbeat directional reversals. The larval heart contracts 24% slower than the adult heart, and hemolymph travels across the larval dorsal vessel at a velocity that is 68% slower than what is seen in adults. By fluorescently labeling muscle tissue we show that although the general structure of the heart and its ostia are similar across life stages, the heart-associated alary muscles are significantly less robust in larvae. Furthermore, unlike the adult ostia, which are the entry points for hemolymph into the heart, the larval ostia are almost entirely lacking in incurrent function. Instead, hemolymph enters the larval heart through incurrent openings located at the posterior terminus of the heart. These posterior openings are structurally similar across life stages, but in adults have an opposite, excurrent function. Finally, the larval aorta and heart differ significantly in the arrangement of their cardiomyocytes. In summary, this study provides an in-depth developmental comparison of the circulatory system of larval and adult mosquitoes.
© 2015. Published by The Company of Biologists Ltd.
BACKGROUND - Ictal asystole is a rare, serious, and often treatable cause of syncope. There are currently limited data to guide management. Characterization of ictal syncope predictors may aid in the selection of high-risk patients for treatments such as pacemakers.
METHODS AND RESULTS - We searched our epilepsy monitoring unit database from October 2003 to July 2013 for all patients with ictal asystole events. Clinical, electroencephalogram, and ECG data for each of their seizures were examined for their relationships with ictal syncope events. In 10 patients with ictal asystole, we observed 76 clinical seizures with 26 ictal asystole episodes, 15 of which led to syncope. No seizure with asystole duration≤6 s led to syncope, whereas 94% (15/16) of seizures with asystole duration>6 s led to syncope (P=0.02). During ictal asystole events, 4 patients had left temporal seizure onset, 4 patients had right temporal seizure onset, and 2 patients had both. Syncope was more common with left temporal (40%) than with right temporal seizures (10%; P=0.002). Treatment options included antiepileptic drug changes, epilepsy surgery, and pacemaker implantation. Eight patients received pacemakers. During follow-up of 72±95 months, all patients remained syncope free.
CONCLUSIONS - Ictal asystole>6 s is strongly associated with ictal syncope. Ictal syncope is more common in left than in right temporal seizures. A permanent pacemaker should be considered in patients with ictal syncope if they are not considered good candidates for epilepsy surgery.
© 2014 American Heart Association, Inc.
Social impairment is a core feature of schizophrenia, present from the pre-morbid stage and predictive of outcome, but the etiology of this deficit remains poorly understood. Successful and adaptive social interactions depend on one's ability to make rapid and accurate judgments about others in real time. Our surprising ability to form accurate first impressions from brief exposures, known as "thin slices" of behavior has been studied very extensively in healthy participants. We sought to examine affect and social trait judgment from thin slices of static or video stimuli in order to investigate the ability of schizophrenic individuals to form reliable social impressions of others. 21 individuals with schizophrenia (SZ) and 20 matched healthy participants (HC) were asked to identify emotions and social traits for actors in standardized face stimuli as well as brief video clips. Sound was removed from videos to remove all verbal cues. Clinical symptoms in SZ and delusional ideation in both groups were measured. Results showed a general impairment in affect recognition for both types of stimuli in SZ. However, the two groups did not differ in the judgments of trustworthiness, approachability, attractiveness, and intelligence. Interestingly, in SZ, the severity of positive symptoms was correlated with higher ratings of attractiveness, trustworthiness, and approachability. Finally, increased delusional ideation in SZ was associated with a tendency to rate others as more trustworthy, while the opposite was true for HC. These findings suggest that complex social judgments in SZ are affected by symptomatology.
Copyright © 2014 Elsevier B.V. All rights reserved.