Citations

SummaryReversibility in vivo of acute platelet thrombosis in response to specific anticoagulants is analyzed with thrombi that develop in segments (1 cm) of porcine carotid arteries externally crushed with a hemostat. Most thrombi fill the lumens of the injured segments (ca. 1 cm × 3 mm, 1 × w) within 30 min and comprise masses of platelets interpenetrated with neutrophil-lined seepage channels of blood. Continuous quantitative assay of thrombus mass is provided by a gamma detector placed over the injured segments to collect counts from 111In-labeled platelets. Thrombi established 30 min after injury, otherwise stable for 6 h, clear during 30-60 min of continuous infusion of either hirudin, tick anticoagulant or activated porcine protein C, or intermittent activation of endogenous protein C with a latent thrombin reagent. Anticoagulant dose-dependence of thrombus clearance is established for hirudin between 0.01 and 1.0 mg/kg/min. Thrombi become progressively refractory to hirudin between 0.5 and 6 h after injury. Neither heparin nor low-molecular-weight heparin in full (clinical) anticoagulant doses yield significant dethrombosis. It is concluded that, within time limits, controlled thrombin generation in platelet thrombi maintains platelet cohesion without catalyzing irreversible platelet aggregation or clotting of fibrinogen.

AbstractAcute neurologic (and potentially disability prone) conditions are rarely taught and, if so, at the bedside and usually after the fact. Simulation training offers a realistic environment to teach rapid-fire decision making, how to take charge, and how best to approach a deteriorating, acutely ill neurologic patient.Simulating acute neurology is a newly emerging educational program. Proven principles of simulation, which may include teaching technical skills, can be applied to acute neurology (and neurointensive care). Communication skills pertaining to catastrophic neurologic injury with all its ethical ramifications can be taught and practiced. There is a growing need for well-designed, tested teaching scenarios and a need to validate this approach. This review provides an overview of the potential opportunities available in medical institutions with a simulation center.

AbstractNeurology trainee assessment is a required component of the education feedback loop, allowing programs and trainees to measure their progress toward established educational goals. In the era of competency-based medical education, assessment systems should be designed to inform decisions about each trainee's acquisition of the many competencies required for independent clinical neurology practice. In addition to the need to inform trainees and programs regarding trainee performance, assessment systems must be equipped to satisfy requirements established by accrediting bodies. Educational goals should be thoughtfully established prior to assessment system design to ensure that assessment priorities align with the overall goal of equipping graduates to deliver high-quality neurologic care. This article provides an overview of modern principles of medical education as they can be applied to neurologic education, complemented by practical recommendations for neurologic educators to develop or improve assessment systems within their own training programs.

Background Platelet microparticles (PMPs) and their abundance in the blood are a prognostic biomarker in thrombotic disorders and cancer. Nanoscale flow cytometry (nFC) is ideal for high-throughput analysis of PMPs but these clinical assays have not been developed previously. Objective This article demonstrates that nFC is a suitable technology to enumerate PMPs present in plasma samples in a clinical setting. Materials and Methods nFC was performed using the Apogee A50-Micro instrument. Instrument settings and acquisition parameters were developed with the use of fluorescent beads and plasma samples. Sample preparation and handling was also optimized. Results nFC allows for linear detection of particles between approximately 200 and 1,000 nm based on calibration beads and was dependent on dilution factor and flow rate. Linearity in event analysis as samples became more diluted was lost when events approximately 100 nm were gated while linearity was maintained despite dilution of sample in events larger than 200 nm in diameter. Higher flow rates lead to an under-estimation of events analysed per microlitre of analyte and this was more pronounced when plasma samples were not diluted more than 1/20×. Conclusion nFC offers multi-parametric analysis of PMPs when optimal calibration of acquisition and sample processing settings is performed. Analysis of plasmas from metastatic prostate cancer patients and leukaemia patients revealed that PMP levels were larger than 100 nm and were equally abundant in patients that responded to or failed androgen deprivation therapy or between patients representing different stages of leukaemia.

AbstractPatients with pectus excavatum (PE) frequently present with complaints of exercise intolerance and cardiopulmonary symptoms. There continues to be controversy regarding the physiologic benefits of repair. The aim of this review is to summarize and discuss recent data regarding the cardiopulmonary effects of PE deformity and the evidence for improvement obtained after surgical repair including (1) a greater efficiency of breathing (chest wall mechanics), (2) improvement in pulmonary restrictive deficits, (3) an increase in cardiac chamber size and output, with improved cardiac strain and strain rate, and (4) improvement in exercise capacity.

Background Management of scapholunate (SL) ligament disruption is a challenging problem. The reduction and association of the scaphoid and lunate (RASL) procedure has been described with varying results. This study assessed the outcomes of the RASL procedure. Purpose The objective of this study was to assess the outcomes of patients undergoing the RASL procedure at our institution in regard to pain relief, range of motion, radiographic and functional outcomes, complications, and reoperations. Materials and Methods Twelve patients with symptomatic chronic SL instability underwent the RASL procedure. The mean age was 35 years. The mean time from injury to surgery was 40 weeks. The mean follow-up was 89 months. Outcomes included visual analog score for pain, wrist range of motion, grip strength, and Mayo Wrist Scores. Preoperative and postoperative radiographs were reviewed. Results Pain scores improved in 10 wrists. Range of motion and grip strength worsened. The average Mayo Wrist Score was 63.3. The mean SL diastasis and angle improved, but seven wrists developed progressive degenerative changes, with two requiring a salvage procedure. Symptomatic progressive screw lucency occurred in eight wrists requiring screw removal. Conclusion The RASL procedure can improve SL widening but has a high rate of early failure and reoperation. Following reoperation, long-term follow-up demonstrates reasonable long-term durability in some cases. Level of Evidence This is a Level IV, therapeutic case study.

Background The treatment of lymphatic leaks and lymphoceles in the groin can be challenging with no optimal management determined to date. We postulate that indocyanine green (ICG) lymphangiography improves visualization of the site of a lymphatic leak and can optimize their management. Methods A retrospective review was conducted of all cases in which ICG lymphangiography was used in the management of lymphatic leaks in the groin over an 18-month span. The inciting surgical procedure resulting in the leak was determined. Following thorough debridement, ICG was injected intradermally in the distal extremity and the site of the lymphatic leak was documented (superficial or deep) and oversewn. Outcomes were reported with regard to healing, infection, time to drain removal, and adjunctive procedures. Results Fifteen patients underwent ICG lymphangiography during the surgical treatment of a lymphatic leak in the groin during the study period. In all cases, the site of the lymphatic leak was accurately identified and oversewn. In eight cases, the site of the lymphatic leak was in the subcutaneous tissue superficial to the femoral vessels rather than medial to the femoral vessels in the area of the lymph node basin. A local muscle flap was used in 10 cases simultaneously. All wounds healed primarily without an associated wound or infection. Conclusion ICG lymphangiography facilitated the identification of lymphatic leaks in the groin and optimized their management in these challenging cases, many of which may have been missed if the area around the inguinal lymph node basin was treated exclusively.

AbstractOculomotor evaluation as part of videonystagmography is an integral tool in the assessment of vestibular function providing a global assessment of the neurological pathways associated with oculomotor function. The value of an oculomotor evaluation for pediatric evaluation is well established; however, many questions can also arise with the application to the pediatric population. Oculomotor function is age dependent which can have a significant effect on the test results obtain in children. The underlying neural substrates and age effects are discussed across the literature with specific results from recent research using clinical oculomotor equipment and protocols. The evidence suggests there are several key differences in the pediatric population compared with adults. These include longer saccade latencies, reduced smooth pursuit gain, increased optokinetic asymmetry, increased variability in all responses, and increased artifact in saccade and smooth pursuit testing.