Search

T cell receptor clonotype tracking is a powerful tool for interrogating T cell mediated immune processes. New methods to pair a single cell’s transcriptional program with its T cell receptor (TCR) identity allow monitoring of T cell clonotype-specific transcriptional dynamics. While these technologies have been available for human and mouse T cells studies, they have not been developed for Rhesus Macaques, a critical translational organism for autoimmune diseases, vaccine development and transplantation. We describe a new pipeline, ‘RM-scTCR-Seq’, which, for the first time, enables RM specific single cell TCR amplification, reconstitution and pairing of RM TCR’s with their transcriptional profiles. We apply this method to a RM model of GVHD, and identify and track in vitro detected alloreactive clonotypes in GVHD target organs and explore their GVHD driven cytotoxic T cell signature. This novel, state-of-the-art platform fundamentally advances the utility of RM to study protective and pathogenic T cell responses.

Introduction Venous thromboembolism (VTE) and bleeding events following total knee and hip arthroplasty (TKA/THA) are associated with significant morbidity. Clinical guidelines recommend administration of pharmacologic VTE prophylaxis post-operatively, although controversy exists regarding optimal prophylactic strategies. Methods We performed a retrospective cohort study in patients who underwent elective TKA/TKA in an academic medical center. Patients were stratified by surgery type (TKA/THA) and VTE risk determined by a novel risk stratification protocol and compared pre- and post-protocol implementation. Patients received warfarin pre-protocol and either aspirin or warfarin post-protocol for VTE prophylaxis. Natural language processing identified VTE events and ICD codes were used to identify bleeding events, with all events validated manually. Results A total of 1379 surgeries were included for analysis, 839 TKAs and 540 THAs. Post-protocol implementation, 445 (94.1%) patients following TKA and 294 (97.4%) patients following THA received aspirin for VTE prophylaxis. A significant reduction in bleeding events (hazard ratio [HR] = 0.19, p = 0.048) was observed in low-risk THA patients treated with aspirin (post-protocol) compared patients treated with warfarin (pre-protocol). Bleeding events did not differ significantly between low-risk TKA patients treated with aspirin or warfarin. No significant differences in VTE events were observed following the protocol implementation. Conclusions The use of a novel risk stratification system to guide VTE prophylaxis selection between aspirin or warfarin following TKA and THA appears safe and effective. Among low-risk patients, aspirin use was associated with fewer bleeding events following THA, without an observed increase in VTE events.

Introduction Venous thromboembolism (VTE) including deep vein thrombosis (DVT) or pulmonary embolism (PE) is associated with reduced survival, poorer quality of life, and substantial health-care-costs. Limited research, primarily qualitative, suggests that those with VTE may have elevated fear of recurrence, and associated emotional dysfunction and distress. Methods A national online survey was administered to 907 patients who had experienced a VTE event in the past two years. The survey assessed for the prevalence of self-reported bleeding harms associated with VTE, the levels of anxiety, depression, cognitive dysfunction and distress experienced by patients, and a range of potential psychosocial correlates that may be associated with these bleeding or emotional harms. Results The majority (63.0%) of respondents had experienced at least one bleeding related harm following their VTE diagnosis, and 40.6% indicated they experienced fear of another clot often or almost all the time. One-in-four (24.7%) and one-in-ten (11.6%) had abnormal levels of anxiety and depression, respectively. Structural equation modeling was used to define two composite latent bleeding harm and emotional harm factors. Emotional and bleeding harms were associated with younger age, a belief that one's health is due to luck, having multiple comorbidities, having a history of prior VTE events, having multiple barriers to VTE care, and experiencing medical mistakes in diagnosis or treatment. Emotional harms were uniquely predicted by having poorer health literacy, having low self-reported medication adherence, belief others are responsible for one's health, and more recent VTE events. Bleeding harms were uniquely predicted by having a lower frequency of primary care provider contact and having a history of switching between warfarin and direct oral anticoagulants for VTE treatment. Conclusions The findings show high levels of self-reported bleeding and emotional harms in a general population of VTE sufferers that are clearly associated with readily identifiable demographic, health status, and psychosocial characteristics. These represent targets for intervention and changes in clinical practice.

We report on a method of photoemissive film growth that controls stoichiometry in real time. We show that stoichiometry control using a feedback loop is possible because (a) photoemissive properties exhibit a distinct dependence on the stoichiometric composition and (b) stoichiometric composition strongly depends on the ratio of the incident fluxes. The reported results were obtained on Cs3Sb but are expected to be relevant to other alkali antimonides and tellurides.

A number of factors contribute to interlaboratory variation of international normalized ratio (INR) results. This variability can lead to differences in clinical decision-making. This prospective cohort study evaluated the accuracy, precision, and clinical decision-making variability of two point-of-care (POC) devices (CoaguChek XS and the Coag-Sense) to a clinical laboratory method of INR measurement as the 'reference' and by using the laboratory's accuracy standard (±25% of the reference INR). Study subjects included adults taking warfarin undergoing a POC INR with each device and a laboratory INR on the same day and evaluated differences in clinical decision-making using a warfarin nomogram. A correction factor was derived for each POC method to estimate the corresponding laboratory INR for POC INRs more than 3.0. A total of 100 patient encounters (76 unique patients) included INR testing by all three methods. Both POC devices demonstrated excellent precision across the entire range (r = 0.98), but poor accuracy relative to the laboratory standard for POC INRs greater than 3.0 (accuracy CoaguChek 19% and Coag-Sense 35%). A correction factor applied to POC INRs greater than 3.0 improved accuracy to 99% for both devices. Applying the correction factor also significantly reduced differences in clinical decision-making (49-28% for CoaguChek and 56-40% for Coag-Sense, P < 0.001). Both POC devices demonstrated poor accuracy for INRs over 3.0. A device-specific, institution-specific correction factor applied to POC INRs greater than 3.0 can provide better accuracy of INR measurement and can significantly reduce variability in warfarin dosing decisions. More study is needed to assess impact on clinical adverse events.

Background Clinical guidelines recommend against routine use of thrombophilia testing in patients with acute thromboembolism. Thrombophilia testing rarely changes acute management of a thrombotic event. Objective To determine appropriateness of thrombophilia testing in a teaching hospital. Design Retrospective cohort study. Setting One academic medical center in Utah. Participants All patients who received thrombophilia testing between July 1, 2014, and December 31, 2014. Main measurements Proportion of thrombophilia tests occurring in situations associated with minimal clinical utility, defined as tests meeting at least 1 of the following criteria: discharged before results available; test type not recommended; testing in situations associated with decreased accuracy; duplicate testing; and testing following a provoked thrombotic event. Results Overall, 163 patients received a total of 1451 thrombophilia tests for stroke (50% of tests; 35% of patients), venous thromboembolism (21% of tests; 21% of patients), and pregnancy-related conditions (15% of tests; 25% of patients). Of the 39 different test types performed, the most common were cardiolipin IgG and IgM antibodies (9% each), lupus anticoagulant (9%), and s2-glycoprotein 1 IgG and IgM antibodies (8% each). In total, 911 tests (63%) were performed in situations associated with minimal clinical utility, with 126 patients (77%) receiving at least one such test. Only 2 patients (1%) had clear documentation of being offered genetic consultation. Conclusions Thrombophilia testing in this single-center study was often associated with minimal clinical utility. Strategies to improve testing practices (eg, hematology specialty consult prior to inpatient testing, improved order panels) might help minimize inappropriate testing and promote value-driven care.

Background and Purpose: This stroke center has neuro-interventional capabilities and is part of a five hospital network surrounding a metropolitan area. As the center that offers mechanical thrombectomy, patients are received for this procedure from the other hospitals in the network in addition to other outside facilities. The time to transfer these patients was taking too long, sometimes hours, and a way to shorten that time was needed to improve patient outcomes. Methods: The stroke team decided to use the Code Stroke nurse to facilitate this process. A process was put into place in which the receiving facility pulls the patient in rather than waiting for the sending facility to push the patient out. The Code Stroke nurse, once learning of the acceptance of the patient by the interventionalist, proactively calls the sending facility to get report, instructs that facility to call EMS for transfer, and records an estimated time of arrival (ETA) for the patient. This information is then disseminated to the rest of the stroke team to prepare for the patient’s arrival. Results: Before implementation of this process, the average time to receive these transfers was approximately 120 minutes. After the Pull Technique was implemented, the average time of transfer is 40 minutes. This is a reduction of 67% of time to transfer. Conclusion: Decreasing the time of transfer can significantly impact the outcome for these patients. This process has shown a lot of promise and is continuing to be evaluated. Not only has the time of transfer decreased, the sending facilities are happier because some of the burden of facilitating the transfer is taken by the receiving facility, and the receiving facility is even more prepared to receive the patient leading to decreased door-to-device (DTD) times.

Results of a research project to quantify and improve the accuracy of point-of-care (POC) International Normalized Ratio (INR) values are reported.The accuracy of POC INR values relative to laboratory-measured INR values was retrospectively assessed in a cohort of patients with same-day INR determinations by both methods. Univariate linear regression was performed to derive a correction factor for POC INR values of3; this correction factor was validated in a second cohort.In the derivation cohort (259 patients and 344 paired INR results), agreement of POC values with corresponding laboratory INR values at two specified thresholds (±15% and ±25%) was 51.2% and 66.6%, respectively; for POC INR values of3 (n = 205), agreement was lower (24.9% and 44.9%, respectively). Univariate linear regression yielded a coefficient of 0.77 (95% confidence interval, 0.76-0.79; p0.001). Applying a correction factor of 0.8 to POC INR values in a validation cohort (169 patients and 209 paired INR values) significantly improved the accuracy of POC INR values of3 relative to laboratory values (from 7% to 71.1% at the lower threshold and from 23.5% to 88.8% at the higher threshold, p0.0001 for both comparisons).Agreement between POC and laboratory INR results in one institution was poor, especially when POC INR values exceeded 3. Application of an institution-specific correction factor to POC INR values of3 improved agreement with laboratory INR results but would not have significantly reduced differences in protocol-based warfarin dosage adjustments.

Calibration of computationally expensive watershed models is more feasible with algorithms that require fewer simulations. This paper compares the performance of seven global optimization algorithms on a 14-parameter and an 8-parameter watershed calibration problem. The optimization algorithms include Shuffled Complex Evolution (SCE), Differential Evolution (DE), an evolutionary algorithm that uses Radial Basis Function (RBF) approximation (ESGRBF), and four types of local optimization methods coupled with the Multi-Level Single Linkage (MLSL) multistart procedure. The four local optimization algorithms are: Sequential Quadratic Programming, which is a derivative-based method; Unconstrained Optimization by Quadratic Approximation (UOBYQA), which is a derivativefree trust-region method; Pattern Search; and Implicit Filtering. The results indicate that ESGRBF is the most effective algorithm on the two calibration problems, followed by Implicit Filtering coupled with the MLSL multistart approach. He...

The spectral and angular radiation properties of gold-silica-gold multilayer nanoshells are investigated using Mie theory for concentric multilayer spheres. The spectral tunability of multilayer nanoshells is explained and characterized by a plasmon hybridization model and a universal scaling principle. A thinner intermediate silica layer, scaled by particle size, red shifts the plasmon resonance. This shift is relatively insensitive to the overall particle size and follows the universal scaling principle with respect to the resonant wavelength of a conventional silica-gold core-shell nanoshell. The extra tunability provided by the inner core further shifts the extinction peak to longer wavelengths, which is difficult to achieve on conventional sub-100 nm nanoshells due to limitations in synthesizing ultrathin gold coatings. We found multilayer nanoshells to be more absorbing with a larger gold core, a thinner silica layer, and a thinner outer gold shell. Both scattering intensity and angular radiation pattern were found to differ from conventional nanoshells due to spectral modulation from the inner core. Multilayer nanoshells may provide more backscattering at wavelengths where silica-gold core-shell nanoshells predominantly forward scatter.