Electrophoresis of a dielectric droplet with constant surface charge density.

Electrophoresis of a dielectric fluid droplet with constant surface charge density is investigated theoretically in this study. A pseudo-spectral method based on Chebyshev polynomials is adopted to solve the governing electrokinetic equations. It is found, among other things, that the larger the electrolyte strength in the ambient solution is, the slower the droplet moves in general. This is due to the strong screening effect of the large amount of indifferent counterions in the neighborhood of the droplet, with no reinforcement of potential-determining ions adsorbing to the droplet surface. The droplet comes to a complete halt eventually. Critical points are discovered for highly charged droplets, at which the droplet surface becomes immobile and the interior fluid stops recirculating. The droplet moves like a rigid particle with constant mobility regardless of its viscosity, a situation referred to as the "solidification phenomenon." The deadlock between the spinning motions on the charged droplet surface induced by the electric driving force and the hydrodynamic driving force respectively is responsible for this peculiar phenomenon. This is also observed for a dielectric droplet with constant surface electric potential. We demonstrate here that it occurs in the constant surface charge density situation as well.

Price transparency implementation: Accessibility of hospital chargemasters and variation in hospital pricing after CMS mandate.

BACKGROUND: National regulations have increasingly focused on transparency in hospital billing and pricing practices. A January 2019 federal mandate required hospitals to publicize lists of billable procedures and items known as chargemasters. METHODS: We identified the 500 top self-pay/uninsured revenue grossing hospitals nationally and searched each hospital's website for a chargemaster. Corresponding items were matched across chargemasters. Intrahospital and interhospital price variation were calculated. To investigate variation in item naming, a name variant and fuzzy matching search was conducted for fifteen common chargemaster items. RESULTS: Of 500 hospitals in this study, 69 (13.8%) had chargemasters that were inaccessible and 30 (6.0%) had chargemasters that did not meet mandated requirements. Among the remaining 431 hospitals, the mean interhospital and intrahospital variation in pricing for identical items was 18% (SD 28%) and 28% (SD 29%), respectively. 388 hospitals listed multiple prices for the same item, with a mean of 687.3 duplicated items (SD 1157.7). Among fifteen common chargemaster items, each item was associated with an average of 275 (SD 213) unique name variants. Interhospital price variation of these items ranged from 53% (transthoracic echocardiogram) to 243% (furosemide 40 mg). CONCLUSIONS: Many chargemasters have barriers to access, and item naming is inconsistent across chargemasters. There is significant interhospital price variation for similar items. IMPLICATIONS: Chargemasters are uninterpretable for the purpose of patient price comparison in their current form. Further regulatory efforts are necessary to increase price transparency and enhance the ability of patients to compare hospital prices.

Chondrosarcoma Metastasis to the Choroid.

We report a rare case of chondrosarcoma metastatic to the choroid. A 64-year-old male with a history of chondrosarcoma metastatic to the lungs and to the spine presented with blurred vision. A choroidal tumor was found. Fine-needle biopsy confirmed the histologic identity of the tumor as chondrosarcoma. Metastatic spread of chondrosarcoma to the eye is extremely rare. When present, lesions may grow rapidly, and systemic prognosis is poor. Co-management with medical oncology is of utmost importance. This is the third case of chondrosarcoma metastatic to the choroid in the literature and the first with bilateral involvement.

Role of Core Number and Location in Targeted Magnetic Resonance Imaging-Ultrasound Fusion Prostate Biopsy.

The optimal method of magnetic resonance imaging (MRI)-ultrasound (US) fusion biopsy to adequately sample regions of interest (ROIs) remains unknown. We sought to determine the number and location of cores needed to adequately detect clinically significant prostate cancer (PCa). We identified patients undergoing MRI-US fusion prostate biopsy at our institution for known history or clinical suspicion of PCa. Multiparametric MRI studies were reviewed using Likert and Prostate Imaging Reporting and Data System (PI-RADS) v2 schema. Multiple targeted cores were taken from each ROI followed by 12-core systematic biopsy. In a distinct cohort of patients, lesions were targeted using a predetermined five-core template. We estimated cancers detected through sampling of five or fewer cores, assessed by core number and core location. We identified 744 patients with 581 lesions with PCa. Seventy-seven percent (279/361) of Gleason (G) ≥3+4 tumors and 72% (137/189) of G >3+4 tumors were detected on two-core sampling. Relative to all targeted cores, a two-core approach missed 16% of clinically significant cancers at first biopsy, 27% in prior negative, and 32% in active surveillance patients. Detection of G ≥3+4 cancers did not differ by core location. Sampling of two cores of ROIs misses nearly one-quarter of clinically significant PCa detected on additional sampling. PATIENT SUMMARY: We aimed to understand how the number of cores obtained from a suspicious area during prostate magnetic resonance imaging-ultrasound fusion biopsy affects cancer detection. We found that sampling of five cores missed substantially fewer cancers compared to two cores.

Youth and Parent Experiences in a Multidisciplinary Gender Clinic.

Purpose: To assess youth and parent/caregiver satisfaction with care at a pediatric multidisciplinary gender clinic. Methods: Transgender/gender nonconforming youth (n=33) and their parent/caregiver (n=29) completed self-report questionnaires and individual interviews (n=20) about experiences and satisfaction with care. Results: Quantitatively, participants reported being extremely satisfied with care experiences (parents 97%; youth 94%). Qualitatively, main themes included (1) affirmation due to use of preferred name/pronouns, (2) access barriers due to scheduling and readiness assessments, and (3) positive interactions with Care Navigator. Conclusion: Youth and parents/caregivers are highly satisfied with multidisciplinary, coordinated health care for transgender/gender nonconforming youth; however, some challenges remain.

Analysis of Patient-Reported Barriers to Diabetic Retinopathy Follow-Up.

BACKGROUND AND OBJECTIVES: Close follow-up of diabetic retinopathy (DR) has been linked to improved visual outcomes. This study elucidates patient-identified barriers to DR follow-up in a diverse urban clinic population. PATIENTS AND METHODS: Patients 18 years of age or older with DR or macular edema were interviewed using a 21-question survey on attitudes and barriers toward care. Univariate and multivariate logistic analysis identified barriers associated with non-compliance to follow-up. RESULTS: Two hundred nine patients participated with mean age of 58.2 years and hemoglobin A1c of 8.5%. The most common barriers cited were long waiting times (46.4%), other medical conditions (35.9%), forgetting (28.2%), and inability to leave work (9.1%). In a multivariate analysis, forgetting (odds ratio [OR]: 4.35) and other medical conditions (OR: 1.91) were barriers independently associated with non-compliance. Having proliferative DR was associated with other medical conditions in univariate (OR: 4.60) and multivariate analysis (OR: 4.35). CONCLUSION: Patients with DR who report other medical conditions or forgetting have a higher risk of non-compliance to follow-up. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:99-105.].

Determinants of Active Surveillance in Patients With Small Renal Masses.

OBJECTIVE: To evaluate trends in the utilization of active surveillance (AS) in a nationally representative cancer database. AS has been increasingly recognized as an effective strategy for patients with small renal masses but little is known about national usage patterns. METHODS: We identified patients with clinical T1a renal masses within the National Cancer Database in 2010 through 2014. Patients were classified according to initial management strategy received including AS, surgery, ablation, or other treatment. We characterized time trends in the use of AS vs definitive therapy and examined clinical and socio-demographic determinants of AS among patients with small renal masses using multivariable logistic regression models. RESULTS: We identified 59,189 patients who satisfied the inclusion criteria. Of the total cohort, 1733 (2.9%) individuals received initial management with AS, while 57,456 (97.1%) received definitive treatment. Surveillance rates remained below 5% in all years. On multivariate analysis, patient age (OR: 1.08, 95% CI 1.08-1.09), smaller tumor size of <2 cm vs ≥2 cm (OR: 2.43, 95% CI: 2.20-2.7, P < .0001), management at an academic center vs community center (OR: 2.05, 95% CI: 1.83-2.29), and African American vs Caucasian race (OR: 1.56, 95% CI:1.35-1.80) were independently associated with use of AS as initial management. CONCLUSION: In a representative national cohort of patients with small renal masses, we observed clinical and facility-level differences in the utilization of active surveillance in patients with T1a renal masses. Further investigation is warranted to better understand the forces underlying initial management decisions for patients with small renal masses.

Comparison of Aberrant Behavior Checklist profiles across Prader-Willi syndrome, Down syndrome, and autism spectrum disorder.

Prader-Willi syndrome (PWS, OMIM # 176270) and Down syndrome (DS, OMIM #190685) are neurodevelopmental genetic disorders with higher rates of autism spectrum disorder (ASD). The Aberrant Behavior Checklist (ABC) is a caregiver rating scale that assesses maladaptive behaviors. Overlapping symptoms exist between PWS, DS, and ASD, including maladaptive behaviors. We aimed to evaluate ABC profiles between PWS, DS, and ASD alone (without known genetic syndrome). In addition, we hypothesized PWS and DS with a comorbid ASD positive screen or diagnosis would have similar ABC profiles to ASD alone. ABC data from the following cohorts were analyzed: PWS (Seattle Children's Hospital, n = 28, mean age = 12.8 ± 4.9 years; University of Florida, n = 35, mean age = 9.3 ± 7.1 years), DS (Johns Hopkins, n = 406, mean age = 8.1 ± 2.4 years), and ASD (University of Florida, n = 102, mean age = 10.8 ± 3.5 years). ASD alone had significantly higher ABC scores. Subgroups of PWS and DS with a comorbid ASD positive screen or diagnosis had similarities in scores with the ASD only group, with subscale patterns unique to each syndrome. The ABC indicated worse maladaptive behaviors in children with ASD, including those with genetic syndromes. Although more studies are needed to evaluate the utility and the accuracy of the ABC as a tool to screen for ASD in special populations, it may be a useful adjunct in screening those children with PWS or DS who need more in depth ASD evaluation.

Core Genome Multilocus Sequence Typing: a Standardized Approach for Molecular Typing of Mycoplasma gallisepticum.

Mycoplasma gallisepticum is the most virulent and economically important Mycoplasma species for poultry worldwide. Currently, M. gallisepticum strain differentiation based on sequence analysis of 5 loci remains insufficient for accurate outbreak investigation. Recently, whole-genome sequences (WGS) of many human and animal pathogens have been successfully used for microbial outbreak investigations. However, the massive sequence data and the diverse properties of different genes within bacterial genomes results in a lack of standard reproducible methods for comparisons among M. gallisepticum whole genomes. Here, we proposed the development of a core genome multilocus sequence typing (cgMLST) scheme for M. gallisepticum strains and field isolates. For development of this scheme, a diverse collection of 37 M. gallisepticum genomes was used to identify cgMLST targets. A total of 425 M. gallisepticum conserved genes (49.85% of M. gallisepticum genome) were selected as core genome targets. A total of 81 M. gallisepticum genomes from 5 countries on 4 continents were typed using M. gallisepticum cgMLST. Analyses of phylogenetic trees generated by cgMLST displayed a high degree of agreement with geographical and temporal information. Moreover, the high discriminatory power of cgMLST allowed differentiation between M. gallisepticum strains of the same outbreak. M. gallisepticum cgMLST represents a standardized, accurate, highly discriminatory, and reproducible method for differentiation among M. gallisepticum isolates. cgMLST provides stable and expandable nomenclature, allowing for comparison and sharing of typing results among laboratories worldwide. cgMLST offers an opportunity to harness the tremendous power of next-generation sequencing technology in applied avian mycoplasma epidemiology at both local and global levels.

Negative Multiparametric Magnetic Resonance Imaging of the Prostate Predicts Absence of Clinically Significant Prostate Cancer on 12-Core Template Prostate Biopsy.

OBJECTIVE: To determine the negative predictive value of multiparametric magnetic resonance imaging (mpMRI), we evaluated the frequency of prostate cancer detection by 12-core template mapping biopsy in men whose mpMRI showed no suspicious regions. METHODS: Six hundred seventy patients underwent mpMRI followed by transrectal ultrasound (TRUS)-guided systematic prostate biopsy from December 2012 to June 2016. Of this cohort, 100 patients had a negative mpMRI. mpMRI imaging sequences included T2-weighted and diffusion-weighted imaging, and dynamic contrast enhancement sequences. RESULTS: The mean age, prostate-specific antigen, and prostate volume of the 100 men included were 64.3 years, 7.2 ng/mL, and 71 mL, respectively. Overall cancer detection was 27% (27 of 100). Prostate cancer was detected in 26.3% (10 of 38) of patients who were biopsy-naïve, 12.1% (4 of 33) of patients who had a prior negative biopsy, and in 44.8% (13 of 29) of patients previously on active surveillance; Gleason grade ≥7 was detected in 3% of patients overall (3 of 100). The negative predictive value of a negative mpMRI was 73% for all prostate cancer and 97% for Gleason ≥7 prostate cancer. CONCLUSION: There is an approximately 3% chance of detecting clinically significant prostate cancer with systematic TRUS-guided biopsy in patients with no suspicious findings on mpMRI. This information should help guide recommendations to patients about undergoing systematic TRUS-guided biopsy when mpMRI is negative.

Perfusion MRI in Early Stage of Legg-Calvé-Perthes Disease to Predict Lateral Pillar Involvement: A Preliminary Study.

BACKGROUND: Current radiographic classifications for Legg-Calvé-Perthes disease cannot be applied at the early stages of the disease. The purpose of this study was to quantify the perfusion of the femoral epiphysis in the early stages of Legg-Calvé-Perthes disease with use of perfusion magnetic resonance imaging (MRI) and to determine if the extent of epiphyseal perfusion can predict the lateral pillar involvement at the mid-fragmentation stage. METHODS: Twenty-nine patients had gadolinium-enhanced perfusion MRI at the initial stage or early fragmentation stage of Legg-Calvé-Perthes disease and were followed prospectively. The percent perfusion of the whole epiphysis and its lateral third was measured by four independent observers using image analysis software. The radiographs obtained at the mid-fragmentation stage were used for the lateral pillar classification. Intraclass correlation coefficient (ICC) and logistic regression analyses were performed. RESULTS: The mean age (and standard deviation) at diagnosis was 7.7 ± 1.7 years (range, 5.3 to 11.3 years). The mean interval between the MRI and the time of maximum fragmentation was 8.2 ± 5.5 months. The interobserver ICC for the percent perfusion of the lateral third of the epiphysis was 0.90 (95% confidence interval [CI]: 0.83 to 0.95). The mean percent perfusion of the lateral third of the epiphysis was 92% ± 2%, 68% ± 18%, and 46% ± 12% for the hips in which the lateral pillar was later classified as A, B, and C, respectively (p = 0.001). When the perfusion level was ≥90% in the lateral third of the epiphysis, the odds ratio of the lateral pillar being later classified as group A, as opposed to B or C, was 72.0 (CI: 3.5 to 1476). With a perfusion level of ≤55% in the lateral third of the epiphysis, the odds ratio of the lateral pillar being later classified as group C, as opposed to A or B, was 33.3 (CI: 2.8 to 392). Similar results were obtained for the whole epiphysis. CONCLUSIONS: Perfusion MRI measurements of the total epiphysis and its lateral third obtained at the early stages of Legg-Calvé-Perthes disease were predictive of lateral pillar involvement at the mid-fragmentation stage of the disease. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Hypertonic HBOC-201 decreases neutrophil activation after hemorrhagic shock.

OBJECTIVE: To evaluate neutrophil activation after exposure to standard HBC-201 (suspended in lactate Ringer's solution) versus HBOC-201 suspended in hypertonic 7.5% saline solution. METHODS: We use plasma and tissue obtained from pigs subjected to controlled hemorrhagic shock and an ex vivo model of stimulated human whole blood. The pigs were resuscitated with the following (n = 8 per group) standard HBOC-201, or hypertonic HBOC-201. We used HTS 7.5%, Ringer's lactate as control resuscitation. Human blood was stimulated with same fluids. We measured the following neutrophil markers; IL-8, H2O2 in pig plasma, MPO in pig tissue, and H2O2, IL-8, and CD11b/CD18 in human whole blood. RESULTS: H2O2 and IL-8 as well as tissue MPO were significantly decreased in pigs resuscitated with HT-HBOC-201 and HT 7.5%. Ex vivo experiments blood diluted with HTS and HT-HBOC-201 revealed lower expression of CD11b/CD18, H2O2, and IL-8. Blood diluted with HBOC-201 had a higher CD11b/CD18 expression than blood diluted with LR solution. CONCLUSION: Our in vivo and ex vivo experiments indicate that HBOC-201 suspended in hypertonic 7.5% saline solution is associated with significantly less neutrophil activation when compared to standard HBOC-201 suspended in lactate Ringer's solution.

MR perfusion index as a quantitative method of evaluating epiphyseal perfusion in Legg-Calve-Perthes disease and correlation with short-term radiographic outcome: a preliminary study.

BACKGROUND: Current radiographic prognosticators of the outcome of Perthes disease can only be applied after femoral head deformity has occurred. Quantification of femoral head perfusion using the gadolinium-enhanced subtraction magnetic resonance imaging (MRI) technique may serve as an early prognosticator of outcome. The purposes of this study were 2-fold: (1) to develop a reliable method to quantify femoral head perfusion using this MRI technique; and (2) to determine whether the perfusion at early stages of Perthes disease correlates with radiographic deformity after a 2-year follow-up. METHODS: A total of 20 patients meeting the following inclusion criteria were studied: radiographs and MRI obtained of femoral heads predeformity, age between 5 and 13 years, and unilateral disease. MR perfusion index, a measure of perfusion in the epiphysis, was obtained using digital image analysis of subtraction gadolinium-enhanced MRI. Intraobserver and interobserver agreement of this index was assessed by 2 independent observers. MR perfusion index was correlated with a radiographic deformity index (a measure of femoral head deformity) obtained after a minimum of 2 years. RESULTS: The intraobserver agreement assessed by the intraclass correlation coefficient was 0.96 for observer 1 and 0.97 for observer 2. The interobserver agreement of the MR perfusion index was 0.90 for trials 1 and 2. MR perfusion index in the early stages of Perthes disease was highly variable, ranging from 0 to 0.70. After a minimum of 2 years following MRI acquisition, radiographs were obtained and evaluated using the deformity index, a continuous measure of femoral head deformity, by 2 blinded observers. Deformity index at 2-year follow-up showed moderate correlation with predeformity MR perfusion index (r=-0.56, P=0.01, R=0.31). In those patients who were treated nonoperatively, the correlation was stronger (r=-0.79, P=0.006, R=0.63). CONCLUSIONS: MR perfusion index obtained from gadolinium-enhanced subtraction MR images showed a high interobserver agreement. MR perfusion index is highly variable at early stages of Perthes disease, and a lower MR perfusion index correlated with greater radiographic deformity at the 2-year follow-up. This pilot study shows the promise of predeformity MR perfusion index as a possible early prognosticator of outcome in Perthes disease. LEVELS OF EVIDENCE: Prognostic level II.