Safety first: significant risk of air embolism in laparoscopic gasketless insufflation systems.

BACKGROUND: Gasketless laparoscopic insufflator systems are marketed for the ability to prevent desufflation of pneumoperitoneum during laparoscopy. However, surgeons raised concern for possible introduction of non-absorbable room air, including oxygen (O2), with these systems. A community-university collaborative was created to test this hypothesis. METHODS: An artificial abdomen, calibrated to equivalent compliance and volume of an average abdomen, was connected to a flow meter, oxygen concentration sensor, and commercially available laparoscopic gasketless cannula system. A commercially available gasketed cannula system was utilized as a control. Intra-abdominal concentration of oxygen was measured at 0-60 L per minute (L/min) of insufflated carbon dioxide (CO2) aspiration, as would occur during laparoscopic suctioning. For reference, a 5-mm laparoscopic suction device has an aspiration rate of approx. 42 L per minute. At the test facility, room air was 20.5% O2 at 50% humidity. Descriptive and univariate statistics were calculated with p < 0.05 considered significant. RESULTS: At 0 L/min CO2 aspiration, there was minimal (< 0.5%) oxygen detected intra-abdominally. However, with increasing rates of aspiration of pneumoperitoneum, increasing amounts of room air were detected intraabdominally in the gasketless versus gasketed cannula systems (mean ± standard deviation): 14.7 ± 1.2% versus 1.2 ± 0.5%, p < 0.0001 at 5 L/min aspiration, 18.1 ± 0.69% versus 1.1 ± 0.02%, p < 0.0001 at 10 L/min, 50.4 ± 2.19% vs 1.01 ± 0.003%, p < 0.0001 at 20 L/min. Above 25 L/min aspiration, the standard gasketed cannula systems experienced desufflation, but the gasketless system continued to entrain air to maintain insufflation: 64% room air at 30 L/min aspiration, 71% at 40 L/min aspiration, 77% at 50 L/min aspiration, and 84% at 60 L/min aspiration. CONCLUSIONS: Gasketless cannula insufflation systems maintain abdominal insufflation by entraining non-medical room air. Especially at high aspiration rates, the majority of absorbable CO2 was replaced by non-medical room air, increasing potential for gas embolism with poorly absorbed oxygen and nitrogen. Authors have reported these experimental findings to the FDA and companies marketing these devices.

Dysfunction in the ßII spectrin-dependent cytoskeleton underlies human arrhythmia.

BACKGROUND: The cardiac cytoskeleton plays key roles in maintaining myocyte structural integrity in health and disease. In fact, human mutations in cardiac cytoskeletal elements are tightly linked to cardiac pathologies, including myopathies, aortopathies, and dystrophies. Conversely, the link between cytoskeletal protein dysfunction and cardiac electric activity is not well understood and often overlooked in the cardiac arrhythmia field. METHODS AND RESULTS: Here, we uncover a new mechanism for the regulation of cardiac membrane excitability. We report that ßII spectrin, an actin-associated molecule, is essential for the posttranslational targeting and localization of critical membrane proteins in heart. ßII spectrin recruits ankyrin-B to the cardiac dyad, and a novel human mutation in the ankyrin-B gene disrupts the ankyrin-B/ßII spectrin interaction, leading to severe human arrhythmia phenotypes. Mice lacking cardiac ßII spectrin display lethal arrhythmias, aberrant electric and calcium handling phenotypes, and abnormal expression/localization of cardiac membrane proteins. Mechanistically, ßII spectrin regulates the localization of cytoskeletal and plasma membrane/sarcoplasmic reticulum protein complexes, including the Na/Ca exchanger, ryanodine receptor 2, ankyrin-B, actin, and αII spectrin. Finally, we observe accelerated heart failure phenotypes in ßII spectrin-deficient mice. CONCLUSIONS: Our findings identify ßII spectrin as critical for normal myocyte electric activity, link this molecule to human disease, and provide new insight into the mechanisms underlying cardiac myocyte biology.

Dysfunction of the ß2-spectrin-based pathway in human heart failure.

ß2-Spectrin is critical for integrating membrane and cytoskeletal domains in excitable and nonexcitable cells. The role of ß2-spectrin for vertebrate function is illustrated by dysfunction of ß2-spectrin-based pathways in disease. Recently, defects in ß2-spectrin association with protein partner ankyrin-B were identified in congenital forms of human arrhythmia. However, the role of ß2-spectrin in common forms of acquired heart failure and arrhythmia is unknown. We report that ß2-spectrin protein levels are significantly altered in human cardiovascular disease as well as in large and small animal cardiovascular disease models. Specifically, ß2-spectrin levels were decreased in atrial samples of patients with atrial fibrillation compared with tissue from patients in sinus rhythm. Furthermore, compared with left ventricular samples from nonfailing hearts, ß2-spectrin levels were significantly decreased in left ventricle of ischemic- and nonischemic heart failure patients. Left ventricle samples of canine and murine heart failure models confirm reduced ß2-spectrin protein levels. Mechanistically, we identify that ß2-spectrin levels are tightly regulated by posttranslational mechanisms, namely Ca(2+)- and calpain-dependent proteases. Furthermore, consistent with this data, we observed Ca(2+)- and calpain-dependent loss of ß2-spectrin downstream effector proteins, including ankyrin-B in heart. In summary, our findings illustrate that ß2-spectrin and downstream molecules are regulated in multiple forms of cardiovascular disease via Ca(2+)- and calpain-dependent proteolysis.

Structure-Property-Processing Correlations of Graphene Bioscaffolds for Proliferation and Differentiation of C2C12 Cells.

Graphene - an atomically thin layer of carbon atoms arranged in a hexagonal lattice - has gained interest as a bioscaffold for tissue engineering due to its exceptional mechanical, electrical, and thermal properties. Graphene's structure and properties are tightly coupled to synthesis and processing conditions, yet their influence on biomolecular interactions at the graphene-cell interface remains unclear. In this study, C2C12 cells were grown on graphene bioscaffolds with specific structure-property- processing-performance (SP3) correlations. Bioscaffolds were prepared using three different methods - chemical vapor deposition (CVD), sublimation of silicon carbide (SiC), and printing of liquid phase exfoliated graphene. To investigate the biocompatibility of each scaffold, cellular morphology and gene expression patterns were investigated using the bipotential mouse C2C12 cell line. Using a combination of fluorescence microscopy and qRT-PCR, we demonstrate that graphene production methods determine the structural and mechanical properties of the resulting bioscaffold, which in turn determine cell morphology, gene expression patterns, and cell differentiation fate. Therefore, production methods and resultant structure and properties of graphene bioscaffolds must be chosen carefully when considering graphene as a bioscaffold for musculoskeletal tissue engineering.

Implementation of a COVID-19 Vaccine Emergency Department Education Program for Underserved Communities.

Background The COVID-19 pandemic has provided an opportunity for significant reflection on our public health response as providers. Throughout the past two years, we learned that administration of COVID-19 vaccines, rapidly and widely across all communities, has been key to halting the spread of the virus. One significant challenge in promoting a large-scale immunization program is the threat of vaccine hesitancy. A general mistrust in healthcare providers exists across the country, especially in underrepresented minority (URM) communities. Objective This study aims to determine reasons for vaccine hesitancy in an urban emergency department and to provide targeted education on the safety and efficacy of the COVID-19 vaccines to patients. Methods An interprofessional quality improvement team was assembled to develop an educational intervention addressing COVID-19 vaccine safety for vaccine-eligible patients receiving treatment in the emergency department at an urban community hospital where over 70% of patients identify as URM. A survey was conducted to elucidate patients' concerns surrounding the COVID-19 vaccine. Upon completion of the survey, up-to-date safety information and education targeting their surveyed concerns were provided by trained medical students. A follow-up survey was conducted to assess the impact of education on patients' attitudes toward the vaccine. Surveys were developed using standardized scoring systems from the Oxford coronavirus explanations, attitudes, and narratives survey (OCEANS) II study and the Kaiser Foundation. Hesitancy scores before and after education were tabulated to assess the effectiveness of targeted education in improving vaccine hesitancy. Results Patients cited a variety of concerns surrounding the COVID-19 vaccine. The three most common reasons for declining vaccines were potential side effects (67.3% were concerned or extremely concerned), the belief that COVID-19 vaccines are neither effective nor safe (64.5% were concerned to extremely concerned), and the risk of developing COVID-19 infection from the vaccine itself (38.8% were concerned to extremely concerned). This information was used to address these concerns directly with patients, answer questions, clarify information, and encourage patients to get vaccinated. Through this education program, vaccine hesitancy scores improved by an average of 29% indicating an increased likelihood of patients who would get vaccinated in the future. Of patients receiving education, 38% agreed to sign up for a vaccine appointment during the intervention. Conclusion The emergency department often serves vulnerable patient populations. As such, its role in public health in these communities cannot be underestimated. This quality improvement project is a novel method that can be used to develop and implement public health education programs to address specific community needs in the emergency department. These results show that a multidisciplinary healthcare team can provide a measurable change in attitudes about vaccine safety with directed education in the emergency department that can help address vaccine hesitancy in the future.

Towards subpercentage uncertainty proton stopping-power mapping via dual-energy CT: Direct experimental validation and uncertainty analysis of a statistical iterative image reconstruction method.

PURPOSE: To assess the potential of a joint dual-energy computerized tomography (CT) reconstruction process (statistical image reconstruction method built on a basis vector model (JSIR-BVM)) implemented on a 16-slice commercial CT scanner to measure high spatial resolution stopping-power ratio (SPR) maps with uncertainties of less than 1%. METHODS: JSIR-BVM was used to reconstruct images of effective electron density and mean excitation energy from dual-energy CT (DECT) sinograms for 10 high-purity samples of known density and atomic composition inserted into head and body phantoms. The measured DECT data consisted of 90 and 140 kVp axial sinograms serially acquired on a Philips Brilliance Big Bore CT scanner without beam-hardening corrections. The corresponding SPRs were subsequently measured directly via ion chamber measurements on a MEVION S250 superconducting synchrocyclotron and evaluated theoretically from the known sample compositions and densities. Deviations of JSIR-BVM SPR values from their theoretically calculated and directly measured ground-truth values were evaluated for our JSIR-BVM method and our implementation of the Hünemohr-Saito (H-S) DECT image-domain decomposition technique for SPR imaging. A thorough uncertainty analysis was then performed for five different scenarios (comparison of JSIR-BVM stopping-power ratio/stopping power (SPR/SP) to International Commission on Radiation Measurements and Units benchmarks; comparison of JSIR-BVM SPR to measured benchmarks; and uncertainties in JSIR-BVM SPR/SP maps for patients of unknown composition) per the Joint Committee for Guides in Metrology and the Guide to Expression of Uncertainty in Measurement, including the impact of uncertainties in measured photon spectra, sample composition and density, photon cross section and I-value models, and random measurement uncertainty. Estimated SPR uncertainty for three main tissue groups in patients of unknown composition and the weighted proportion of each tissue type for three proton treatment sites were then used to derive a composite range uncertainty for our method. RESULTS: Mean JSIR-BVM SPR estimates deviated by less than 1% from their theoretical and directly measured ground-truth values for most inserts and phantom geometries except for high-density Delrin and Teflon samples with SPR error relative to proton measurements of 1.1% and -1.0% (head phantom) and 1.1% and -1.1% (body phantom). The overall root-mean-square (RMS) deviations over all samples were 0.39% and 0.52% (head phantom) and 0.43% and 0.57% (body phantom) relative to theoretical and directly measured ground-truth SPRs, respectively. The corresponding RMS (maximum) errors for the image-domain decomposition method were 2.68% and 2.73% (4.68% and 4.99%) for the head phantom and 0.71% and 0.87% (1.37% and 1.66%) for the body phantom. Compared to H-S SPR maps, JSIR-BVM yielded 30% sharper and twofold sharper images for soft tissues and bone-like surrogates, respectively, while reducing noise by factors of 6 and 3, respectively. The uncertainty (coverage factor k = 1) of the DECT-to-benchmark values comparison ranged from 0.5% to 1.5% and is dominated by scanning-beam photon-spectra uncertainties. An analysis of the SPR uncertainty for patients of unknown composition showed a JSIR-BVM uncertainty of 0.65%, 1.21%, and 0.77% for soft-, lung-, and bony-tissue groups which led to a composite range uncertainty of 0.6-0.9%. CONCLUSIONS: Observed JSIR-BVM SPR estimation errors were all less than 50% of the estimated k = 1 total uncertainty of our benchmarking experiment, demonstrating that JSIR-BVM high spatial resolution, low-noise SPR mapping is feasible and is robust to variations in the geometry of the scanned object. In contrast, the much larger H-S SPR estimation errors are dominated by imaging noise and residual beam-hardening artifacts. While the uncertainties characteristic of our current JSIR-BVM implementation can be as large as 1.5%, achieving < 1% total uncertainty is feasible by improving the accuracy of scanner-specific scatter-profile and photon-spectrum estimates. With its robustness to beam-hardening artifact, image noise, and variations in phantom size and geometry, JSIR-BVM has the potential to achieve high spatial-resolution SPR mapping with subpercentage accuracy and estimated uncertainty in the clinical setting.

The Appalachia Mind Health Initiative (AMHI): a pragmatic randomized clinical trial of adjunctive internet-based cognitive behavior therapy for treating major depressive disorder among primary care patients.

BACKGROUND: Major depressive disorder (MDD) is a leading cause of disease morbidity. Combined treatment with antidepressant medication (ADM) plus psychotherapy yields a much higher MDD remission rate than ADM only. But 77% of US MDD patients are nonetheless treated with ADM only despite strong patient preferences for psychotherapy. This mismatch is due at least in part to a combination of cost considerations and limited availability of psychotherapists, although stigma and reluctance of PCPs to refer patients for psychotherapy are also involved. Internet-based cognitive behaviorial therapy (i-CBT) addresses all of these problems. METHODS: Enrolled patients (n = 3360) will be those who are beginning ADM-only treatment of MDD in primary care facilities throughout West Virginia, one of the poorest and most rural states in the country. Participating treatment providers and study staff at West Virginia University School of Medicine (WVU) will recruit patients and, after obtaining informed consent, administer a baseline self-report questionnaire (SRQ) and then randomize patients to 1 of 3 treatment arms with equal allocation: ADM only, ADM + self-guided i-CBT, and ADM + guided i-CBT. Follow-up SRQs will be administered 2, 4, 8, 13, 16, 26, 39, and 52 weeks after randomization. The trial has two primary objectives: to evaluate aggregate comparative treatment effects across the 3 arms and to estimate heterogeneity of treatment effects (HTE). The primary outcome will be episode remission based on a modified version of the patient-centered Remission from Depression Questionnaire (RDQ). The sample was powered to detect predictors of HTE that would increase the proportional remission rate by 20% by optimally assigning individuals as opposed to randomly assigning them into three treatment groups of equal size. Aggregate comparative treatment effects will be estimated using intent-to-treat analysis methods. Cumulative inverse probability weights will be used to deal with loss to follow-up. A wide range of self-report predictors of MDD heterogeneity of treatment effects based on previous studies will be included in the baseline SRQ. A state-of-the-art ensemble machine learning method will be used to estimate HTE. DISCUSSION: The study is innovative in using a rich baseline assessment and in having a sample large enough to carry out a well-powered analysis of heterogeneity of treatment effects. We anticipate finding that self-guided and guided i-CBT will both improve outcomes compared to ADM only. We also anticipate finding that the comparative advantages of adding i-CBT to ADM will vary significantly across patients. We hope to develop a stable individualized treatment rule that will allow patients and treatment providers to improve aggregate treatment outcomes by deciding collaboratively when ADM treatment should be augmented with i-CBT. TRIAL REGISTRATION: ClinicalTrials.gov NCT04120285 . Registered on October 19, 2019.

Lower Extremity Splinting: A Head-to-Head Comparison of A Novel One-Step Spray-on Splint Versus Standard Splinting.

INTRODUCTION: Splinting is an essential component of treating many lower extremity musculoskeletal injuries; however, little development has been made in splinting technology. The purpose of this study is to evaluate the efficacy of current immobilization equipment for lower extremity fractures by testing a novel one-step spray-on foam splint (Fast Cast) against structural aluminum malleable (SAM) lower extremity musculoskeletal injuries and 6-inch ACE (3M Corp., Minneapolis, MN, USA) bandage splints. MATERIALS AND METHODS: Six orthopedic surgical residents and two medical students participated in a prospective analysis of austere splinting techniques and equipment that utilized a cadaveric model with a distal third tibia-fibula shaft fracture. Each participant was observed and scored by three fellowship trained attending orthopedic surgeons. All scoring was independent using a 5-point Likert scale based on 10 splinting criteria (50 total points possible), including quality of radiographic reduction, time to completion, safety, and sustain longitudinal traction. The Likert scale is a set of questions that reflects the respondent's degree of agreement or disagreement with a statement. Each of the 10 questions has a range of 1-5. A score of 50 means the splint performed perfectly. The lowest possible score is a 10. The participants utilized standard equipment that included SAM splints and 6-inch ACE wraps (3M Corp., Minneapolis, MN, USA) in their first attempt. A second immobilization attempt was done with a one-step spray-on foam splint (Fast Cast). After each splinting attempt, the reduction was verified with radiographic imaging. Data analysis was performed using standard descriptive statistics, Student's t-tests, and inter-rater reliability was calculated using Cronbach's alpha scores. This project is Institutional Review Board (IRB) exempt. RESULTS: The one-step spray-on foam splinting technique was superior (P < .05) in all parameters of the Likert scale, yielding a mean overall score of 45.1 points (±3.8), safety 4.7 points, longitudinal traction 4.5 points, and time 136 seconds (±23). The SAM resulted in a mean overall score of 33.8 points (±7.3), safety 2.8 points, longitudinal traction 4.1 points, and time 170 seconds (±52). Radiographic rating was 4.1 points (±0.7) for the SAM splint and 4.5 (±0.6) for Fast Cast. The differences in time to completion and radiograph rating did not reach statistical significance (P = .12 and P = .07, respectively). CONCLUSION: A one-step spray-on foam splinting technique demonstrated consistent superiority in reducing fracture motion, potential soft-tissue damage, and sustained longitudinal traction as compared to the standard technique.

Impact of bowtie filter and detector collimation on multislice CT scatter profiles: A simulation study.

PURPOSE: To investigate via Monte Carlo simulations, the impact of scan subject size, antiscatter grid (ASG), collimator size, and bowtie filter on the distribution of scatter radiation in a typical realistically modeled third generation 16 slice diagnostic computed tomography (CT) scanner. METHODS: Full radiation transport was simulated with Geant4 in a realistic CT scanner geometric model, including the imaging phantom, bowtie filter (BTF), collimators and detector assembly, except for the ASGs. An analytical method was employed to quantify the probable transmission through the ASG of each photon intersecting the detector array. Normalized scatter profiles (NSP) and scatter-to-primary-ratio (SPR) profiles were simulated for 90 and 140 kVp beams for different size phantoms and slice thicknesses. The impact of CT scatter on the reconstructed attenuation coefficient factor was also studied as were the modulating effects of phantom- and patient-tissue heterogeneities on scatter profiles. A method to characterize the relative spatial frequency content of sinogram signals was developed to assess the latter. RESULTS: For the 21.4-cm diameter phantom, NSP and SPR increase linearly with collimator opening for both tube potentials, with the 90 kVp scan exhibiting slightly larger NSP and SPR. The BTF modestly modulates scatter under the phantom center, reducing the prominent off-axis lobes by factors of 1.1-1.3. The ASG reduces scatter on the central axis NSP threefold, and reduces scatter at the detectors outside the phantom shadow by factors of 25 to 500. For the phantoms with diameters of 27 and 32 cm, the scatter increases roughly three- and fourfold, respectively, demonstrating that scatter monotonically increases with phantom size, despite deployment of the ASG and BTF. In the absence of a scan subject, the ASG reduces the signal profile arising photons scattered by the BTF. Without ASG, the in-air scatter profile is relatively flat compared to the scatter profile when the ASG is present. For both 90 and 140 kVp photon spectra, the calculated attenuation coefficient decreases linearly with increasing collimation size. For both homogeneous and heterogeneous objects, NSPs are dominated by low spatial frequency content compared to the primary signal. However, the SPR, which quantifies the local magnitude of nonlinear detector response and is dominated by the high frequency content of the primary profile, can contribute strongly to high-spatial frequency streaking artifacts near high-density structures in reconstructed image artifacts. CONCLUSION: Public-domain Monte Carlo codes, Geant-4 in particular, is a feasible method for characterizing CT detector response to scattered- and off-focal radiation. Our study demonstrates that the ASG substantially reduces the scatter radiation and reshapes scatter-radiation profiles and affects the accuracy with which the detector array can measure narrow-beam attenuation due its inability to distinguish between true uncollided primary and narrow-angle coherently scattered photons. Hence, incorporating the impact of detector array collimation into the forward-projection signal formation models used by iterative reconstruction algorithms is necessary to use CT for accurately characterizing material properties. While tissue heterogeneities exercise a modest influence on local NPS shape and magnitude, they do not add significant high spatial frequency content.

Microtensile dentin adhesive bond strength under different positive pulpal pressures.

PURPOSE: To measure the in vitro dentin microtensile bond strength of established adhesives under different hydrostatic pulpal pressures. METHODS: After IRB approval, 24 human extracted third molars were randomly distributed into four adhesive treatment groups: Clearfil-SE (self-etch, water-based), One-Step Plus (total-etch, acetone-based), Peak-SE (self-etch, ethanol-based) and PQ1 (total-etch, ethanol-based, Ultradent). Additionally each group was assigned to be restored under 0.0, 5.0 or 15.0 cm of water pressure. Coronal enamel was removed using 60, 240 & 320-grit wet sandpaper until only dentin was visible. After adhesive placement Filtek Z250 Universal Restorative was applied in five 1.0 mm increments. All teeth were tested at 24 hours for microtensile bond strength and examined for mode of failure under light microscopy (x40). RESULTS: A two-factor ANOVA found a statistically significant effect for adhesives, water pressures and their interaction (P < or = 0.001). Post hoc pairwise comparisons of simple effects using the Ryan-Einot-Gabriel-Welsch Range procedure showed Clearfil-SE stronger than the other adhesives at 5.0 and at 15.0 cm water pressure (P < 0.07). One-Step Plus was weaker than PQ1 and Peak-SE at 5.0 and at 15.0 cm water pressure (P < 0.07). PQ1 and Peak-SE at 0.0, 5.0 and 15.0 cm were not significantly different from each other (P > 0.07). For water pressure comparisons, Clearfil-SE was stronger at 0.0 vs. 5.0 cm water pressure (P < 0.07), while there was no difference for Clearfil-SE between 5.0 and 15.0 cm water pressure (P > 0.07). One-Step Plus was significantly stronger at 0.0 cm water pressure than at 5.0 and 15.0 cm water pressure (P < 0.07), and at 5.0 cm water pressure it was stronger than at 15.0 cm pressure (P < 0.07). Both Peak-SE and PQ1 at 0.0 water pressure were significantly stronger than at 5.0 and 15.0 cm water pressure. There was no difference in strength between 5.0 and 15.0 cm water pressure for either of the two adhesives (P > 0.07).

Open-source automated chemical vapor deposition system for the production of two- dimensional nanomaterials.

The study of two- dimensional (2D) materials is a rapidly growing area within nanomaterials research. However, the high equipment costs, which include the processing systems necessary for creating these materials, can be a barrier to entry for some researchers interested in studying these novel materials. Such process systems include those used for chemical vapor deposition, a preferred method for making these materials. To address this challenge, this article presents the first open-source design for an automated chemical vapor deposition system that can be built for less than a third of the cost for a comparable commercial system. The materials and directions for the system are divided by subsystems, which allows the system to be easily built, customized and upgraded, depending upon the needs of the user. We include the details for the specific hardware that will be needed, instructions for completing the build, and the software needed to automate the system. With a chemical vapor deposition system built as described, a variety of 2D nanomaterials and their heterostructures can be grown. Specifically, the experimental results clearly demonstrate the capability of this open-source design in producing high quality, 2D nanomaterials such as graphene and tungsten disulfide, which are at the forefront of research in emerging semiconductor devices, sensors, and energy storage applications.

Two-stage ionoacoustic range verification leveraging Monte Carlo and acoustic simulations to stably account for tissue inhomogeneity and accelerator-specific time structure - A simulation study.

PURPOSE: Range errors constrain treatment planning by limiting choice of ion beam angles and requiring large margins. Ionoacoustic range verification requires recovering the location of an acoustic source from low frequency signals. A priori information is applied to stably overcome resolution limits of inverse acoustic source imaging in this simulation study. In particular, the accuracy and robustness of ionoacoustic range verification for lateral and oblique delivery of high-energy protons to the prostate is examined. METHODS: Dose maps were computed using GEANT4 Monte Carlo simulations via the TOPAS user interface. Thermoacoustic pulses were propagated using k-Wave software, with initial pressures corresponding to instantaneous dose deposition and piecewise constant maps of tissue properties derived from the planning CT. A database of dose maps with corresponding thermoacoustic emissions and Bragg peak locations, referred to as "control points," were precomputed. Corresponding thermoacoustic emissions were also precomputed. Pulses were recorded at four coplanar locations corresponding to the outer surface of a virtual transrectal array. To model experimental beam delivery, k-Wave results were convolved in time with a Gaussian envelope to account for noninstantaneous proton delivery by a synchrocyclotron. Thermoacoustic pulses were bandlimited below 150 kHz, and amplitudes were directly proportional to charge delivered. To test robustness of our method, white noise was added. Range was estimated in a two-step process. The first step obtained a preliminary range estimate by one-way beamforming. The second step was taken using data corresponding to the "control point" nearest to the preliminary range estimate. For each receiver, the time of flight difference, ∆t, between the measured and control thermoacoustic signals were accurately estimated by applying the Fourier shift theorem. Receiver-Bragg peak distance was then estimated by adding vs ∆t to the known distance of the control point, where vs is soundspeed. A linear system of equations based upon all receiver locations and distances was solved to recover the Bragg peak location. All simulations were performed relative to the planning CT. Because ultrasound (US) images were not available, results were overlaid onto the planning CT. RESULTS: Beamformed estimates from noise-free data tracked all beam locations within 1 cm. Final estimates for oblique and lateral beams were accurate to within 1.0 and 1.6 mm respectively. Average errors of final range estimates for oblique beams from data with SNR = 0 dB were no greater than 2.0 mm. CONCLUSIONS: Ionoacoustic range verification may improve current practice. Ionoacoustic range estimates can be inherently co-registered to ultrasound images of underlying anatomy. To ensure estimates are robust in clinical practice, dose maps based upon the planning CT should be overlaid onto ultrasound volumes acquired at time of treatment and acoustic simulations re-computed to provide a database of control points and corresponding thermoacoustic emissions. Computation times for beamformed estimates are already fast enough for online range verification, but are not accurate enough for a measurement aperture limited to the surface of a transrectal ultrasound probe. Accelerated acoustic simulations will be required to enable online two-stage correction, but offline calculation is already suitable for adaptive planning.

Common human ANK2 variant confers in vivo arrhythmia phenotypes.

BACKGROUND: Human ANK2 (ankyrin-B) loss-of-function variants are directly linked with arrhythmia phenotypes. However, in atypical non-ion channel arrhythmia genes such as ANK2 that lack the same degree of robust structure/function and clinical data, it may be more difficult to assign variant disease risk based simply on variant location, minor allele frequency, and/or predictive structural algorithms. The human ankyrin-B p.L1622I variant found in arrhythmia probands displays significant diversity in minor allele frequency across populations. OBJECTIVE: The objective of this study was to directly test the in vivo impact of ankyrin-B p.L1622I on cardiac electrical phenotypes and arrhythmia risk using a new animal model. METHODS: We tested arrhythmia phenotypes in a new "knock-in" animal model harboring the human ankyrin-B p.L1622I variant. RESULTS: Ankyrin-B p.L1622I displays reduced posttranslational expression in vivo, resulting in reduced cardiac ankyrin-B expression and reduced association with binding-partner Na/Ca exchanger. Ankyrin-B(L1622I/L1622I) mice display changes in heart rate, atrioventricular and intraventricular conduction, and alterations in repolarization. Furthermore, ankyrin-B(L1622I/L1622I) mice display catecholamine-dependent arrhythmias. At the cellular level, ankyrin-B(L1622I/L1622I) myocytes display increased action potential duration and severe arrhythmogenic afterdepolarizations that provide a mechanistic rationale for the arrhythmias. CONCLUSION: Our findings support in vivo arrhythmogenic phenotypes of an ANK2 variant with unusual frequency in select populations. On the basis of our findings and current clinical data, we support classification of p.L1622I as a "mild" loss-of-function variant that may confer arrhythmia susceptibility in the context of secondary risk factors including environment, medication, and/or additional genetic variation.

Anti-CarP antibodies as promising marker to measure joint damage and disease activity in patients with rheumatoid arthritis.

Anti-citrullinated protein antibodies (ACPA) are important serological markers in the diagnosis of rheumatoid arthritis (RA) and are part of the recent disease classification criteria. However, there is a strong need for reliable markers for measuring and predicting joint damage and disease activity. Recently, antibodies directed against carbamylated antigens (anti-CarP antibodies) were identified. A total of 120 RA patients were tested for anti-CCP antibodies using different methods and for anti-CarP antibodies using carbamylated fetal calf serum according to the method described by Shi et al. Additionally, ACPA fine specificities (to three citrullinated peptides) were measured. Disease activity was assessed at baseline using the disease activity score 28 (DAS28) in 80 patients. For 40 RA patients, joint erosion score (JES) was established. The median JES was 14.1 with a standard deviation of 11.5. Anti-CarP antibodies were correlated with joint erosion score (ρ = 0.34, 95% CI 0.03-0.59; p = 0.0332). No correlation between ACPA and joint erosion score was observed. No individual marker correlated with DAS28. When one ACPA peptide was combined with anti-CarP antibodies in a score (ACPA peptide 1 divided by anti-CarP), a statistically relevant correlation was found (p = 0.0264). In this small cohort, the presence of anti-CarP antibodies, but not ACPA correlate with joint erosion score. Anti-CarP antibodies combined with ACPA fine specificities correlated with DAS28. Therefore, anti-CarP antibodies might represent a promising marker to predict joint damage and disease activity in RA patients.

Clinical evaluation of a novel chemiluminescent immunoassay for the detection of anti-citrullinated peptide antibodies.

BACKGROUND: We evaluated the analytical and clinical performances of a novel, automated chemiluminescent immunoassay in comparison with several anti-citrullinated protein antibody (ACPA) assays (2nd and 3rd generations) based on various platforms and technologies. METHODS: Samples from rheumatoid arthritis (RA) patients (n=141) and controls (n=153) were collected based on an ordered ACPA test. All samples were tested with QUANTA Flash® CCP3, QUANTA Lite® CCP3, QUANTA Lite® CCP3.1, CCPlus and EliA® CCP assays. Rheumatoid factor (RF) was determined using Quantex RF(II). An additional cohort consisting of RA patients from three different sources (116, 79 and 50 samples), 61 juvenile idiopathic arthritis (JIA) patients and 233 controls were used in an extended evaluation on QUANTA Flash® CCP3 only. Precision and linearity of the QUANTA Flash® CCP3 were assessed according to CLSI guidelines. RESULTS: All ACPA assays showed good qualitative and quantitative agreements. The Quanta Flash CCP3 assay showed good analytical and clinical performance. Based on the extended cohort, the sensitivity, specificity and likelihood ratios of the novel Quanta Flash® CCP3 were defined as 70.2%, 97.4% and 27.3/0.31, respectively. CONCLUSION: Good agreements between different ACPA assays based on diverse platforms were found. Quanta Flash CCP3 is a reliable test for the fully automated and rapid detection of ACPA.

Atypical clinical presentation of a subset of patients with anti-RNA polymerase III--non-scleroderma cases associated with dominant RNA polymerase I reactivity and nucleolar staining.

INTRODUCTION: Anti-RNA polymerase III (RNAP III) antibodies are highly specific markers of scleroderma (systemic sclerosis, SSc) and associated with a rapidly progressing subset of SSc. The clinical presentation of anti-RNAP III positive patients, onset of Raynaud's phenomenon (RP) and SSc in unselected patients in a rheumatology clinic were evaluated. METHODS: Autoantibodies in sera from 1,966 unselected patients (including 434 systemic lupus erythematosus (SLE), 119 SSc, 85 polymyositis/dermatomyositis (PM/DM)) in a rheumatology clinic were screened by radioimmunoprecipitation. Anti-RNAP III positive sera were also tested by immunofluorescence antinuclear antibodies and anti-RNAP III ELISA. Medical records of anti-RNAP III positive patients were reviewed. RESULTS: Among 21 anti-RNAP III positive patients, 16 met the American College of Rheumatology (ACR) SSc criteria at the initial visit but 5 did not; diagnoses were vasculitis, early polyarthritis, renal failure with RP, interstitial lung disease, and Sjögren's syndrome. The first two patients developed rapidly progressive diffuse SSc. An additional case presented with diffuse scleroderma without RP and RP developed two years later. Anti-RNAP III antibodies in these 6 cases of atypical clinical presentation were compared with those in 15 cases of typical (SSc with RP) cases. Anti-RNAP III levels by ELISA were lower in the former group (P = 0.04 by Mann-Whitney test) and 3 of 6 were negative versus only 1 of 15 negative in the latter (P < 0.05 by Fisher's exact test). Three cases of non-SSc anti-RNAP III positive patients had predominant reactivity with RNAP I with weak RNAP III reactivity and had a strong nucleolar staining. Three anti-RNAP III patients, who did not have RP at the initial visit, developed RP months later. Scleroderma developed prior to RP in 5 out of 16 (31%) in the anti-RNAP III group, but this was rare in patients with other autoantibodies. The interval between the onset of RP to scleroderma was short in anti-RNAP III positive patients. CONCLUSIONS: Anti-RNAP III antibodies are highly specific for SSc; however, a subset of anti-RNAP III positive patients do not present as typical SSc. The interval between RP and scleroderma in this group is short, and 31% of patients developed scleroderma prior to RP in this group. Anti-RNAP III positive patients may not present as typical SSc and detecting anti-RNAP III may have predictive value.