User Experience of Access to Sexual Assault Nurse Examiner and Emergency Contraception in Emergency Departments in the United States: A National Survey

Background

Despite the prevalence of sexual assault presentations to emergency departments (ED) in the United States, current access to sexual assault nurse examiners (SANE) and emergency contraception (EC) in EDs is unknown.

Methods

In this study we employed a "secret shopper," cross-sectional telephonic survey. A team attempted phone contact with a representative sample of EDs and asked respondents about the availability of SANEs and EC in their ED. Reported availability was correlated with variables including region, urban/rural status, hospital size, faith affiliation, academic affiliation, and existence of legislative requirements to offer EC.

Results

Over a two-month period in 2019, 1,046 calls to hospitals were attempted and 960 were completed (91.7% response rate). Of the 4,360 eligible hospitals listed in a federal database, 960 (22.0%) were contacted. Access to SANEs and EC were reported to be available in 48.9% (95% confidence interval [CI] 45.5-52.0) and 42.5% (95% CI 39.4-45.7) of hospitals, respectively. Access to EC was positively correlated with SANE availability. The EDs reporting SANE and EC availability were more likely to be large, rural, and affiliated with an academic institution. Those reporting access to EC were more likely to be in the Northeast and in states with legislative requirements to offer EC.

Conclusion

Our results suggest that perceived access to sexual assault services and emergency contraception in EDs in the United States remains poor with regional and legislative disparities. Results suggest disparities in perceived access to EC and SANE in the ED, which have implications for improving ED practices regarding care of sexual assault victims.

Quantifying Health Outcome Disparity in Invasive Methicillin-Resistant Staphylococcus aureus Infection using Fairness Algorithms on Real-World Data

This study quantifies health outcome disparities in invasive Methicillin-Resistant Staphylococcus aureus (MRSA) infections by leveraging a novel artificial intelligence (AI) fairness algorithm, the Fairness-Aware Causal paThs (FACTS) decomposition, and applying it to real-world electronic health record (EHR) data. We spatiotemporally linked 9 years of EHRs from a large healthcare provider in Florida, USA, with contextual social determinants of health (SDoH). We first created a causal structure graph connecting SDoH with individual clinical measurements before/upon diagnosis of invasive MRSA infection, treatments, side effects, and outcomes; then, we applied FACTS to quantify outcome potential disparities of different causal pathways including SDoH, clinical and demographic variables. We found moderate disparity with respect to demographics and SDoH, and all the top ranked pathways that led to outcome disparities in age, gender, race, and income, included comorbidity. Prior kidney impairment, vancomycin use, and timing were associated with racial disparity, while income, rurality, and available healthcare facilities contributed to gender disparity. From an intervention standpoint, our results highlight the necessity of devising policies that consider both clinical factors and SDoH. In conclusion, this work demonstrates a practical utility of fairness AI methods in public health settings.

Clinical Outcomes and Immunotoxicity in People with HIV (PWH) after Definitive Chemoradiation (CRT) for Anal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Anal cancer disproportionately affects PWH despite antiretroviral therapy. Data on CRT outcomes are limited. Modern IMRT CRT decreases acute toxicity but may exacerbate immune dysregulation from chronic HIV. Although historical CRT has been associated with prolonged CD4 count suppression, little is known about late immunotoxicity in PWH after contemporary CRT. We report clinical outcomes and long term immunotoxicity.

MATERIALS/METHODS

Single-center retrospective review of all PWH confirmed on chart review with anal squamous cell carcinoma without prior pelvic irradiation treated with definitive IMRT CRT. Patient and CRT factors including HIV suppression (<200 copies/mL), mean CD4 count (cells/µL), and receipt of capecitabine (C) or 5-fluorouracil (F) +/- mitomycin (M) were summarized with n (%) or median (interquartile range). Progression-free and overall survival (PFS; OS) were estimated per Kaplan-Meier with 95% confidence intervals and compared with log-rank tests. Mean CD4 count and CD4:CD8 were compared by HIV suppression status (Welch's t-test); longitudinal changes in median CD4 count and CD4:CD8 were compared between baseline vs. nadir (within 6 months of CRT start) and 1-year follow-up for patients with complete data (Wilcoxon signed-rank test).

RESULTS

A total of 23 PWH were treated between 2010-2022, median age 52, median 16 (13 - 19) years after HIV diagnosis; 4 had unsuppressed HIV; AJCC 8th stage I/II/III/IV 5/5/12/1. Radiation dose was median 54 Gy in 30 fractions over 42 (40 - 44) days. Most had C+M (57%); only 43% had 2×M with either C or F. One had neoadjuvant carboplatin/paclitaxel/pembrolizumab. With 2.9 (1.03 - 3.3) years follow-up, median OS was 6.6 (6.2 - unreached [UR]) years. With 2.2 (0.67 - 2.7) years follow-up, median PFS was UR. OS and PFS were similar regardless of HIV suppression status (both P ≥ 0.09). Overall baseline CD4 count was 458 (226 - 484), and CD4:CD8 was 0.54 (0.2 - 0.7). Nadir CD4 was 100 (59 - 126) and CD4:CD8 was 0.3 (0.2 - 0.4). Baseline and nadir CD4 count and CD4:CD8 were lower if HIV-unsuppressed (each P ≤ 0.04). One year after CRT, CD4 count was 252 (102 - 276), while CD4:CD8 was 0.5 (0.2 - 0.7). For 7 patients with repeated values the change in median from baseline to nadir, 6-, and 12-months post-CRT was -282, -549 (both P = 0.02), -480 (P = 0.9) for CD4 counts, and -0.7, -0.5, -0.4 (each P > 0.5) for CD4:CD8 ratios; none had unsuppressed HIV.

CONCLUSION

Definitive IMRT CRT with guideline-concordant doublet chemotherapy for anal cancer in PWH is effective despite unsuppressed HIV. Treatment leads to prolonged immunological changes that may increase the risk of HIV-related morbidity and mortality. Modifiable treatment-related causes of hematoimmunologic toxicity should be investigated further, and immune surveillance after CRT should be considered to better understand impact on quality of life.

Optimizing Dynamic Antibiotic Treatment Strategies against Invasive Methicillin-Resistant Staphylococcus Aureus Infections using Causal Survival Forests and G-Formula on Statewide Electronic Health Record Data

Developing models for individualized, time-varying treatment optimization from observational data with large variable spaces, e.g., electronic health records (EHR), is problematic because of inherent, complex bias that can change over time. Traditional methods such as the g-formula are robust, but must identify critical subsets of variables due to combinatorial issues. Machine learning approaches such as causal survival forests have fewer constraints and can provide fine-tuned, individualized counterfactual predictions. In this study, we aimed to optimize time-varying antibiotic treatment -identifying treatment heterogeneity and conditional treatment effects- against invasive methicillin-resistant Staphylococcus Aureus (MRSA) infections, using statewide EHR data collected in Florida, USA. While many previous studies focused on measuring the effects of the first empiric treatment (i.e., usually vancomycin), our study focuses on dynamic sequential treatment changes, comparing possible vancomycin switches with other antibiotics at clinically relevant time points, e.g., after obtaining a bacterial culture and susceptibility testing. Our study population included adult individuals admitted to the hospital with invasive MRSA. We collected demographic, clinical, medication, and laboratory information from the EHR for these patients. Then, we followed three sequential antibiotic choices (i.e., their empiric treatment, subsequent directed treatment, and final sustaining treatment), evaluating 30-day mortality as the outcome. We applied both causal survival forests and g-formula using different clinical intervention policies. We found that switching from vancomycin to another antibiotic improved survival probability, yet there was a benefit from initiating vancomycin compared to not using it at any time point. These findings show consistency with the empiric choice of vancomycin before confirmation of MRSA and shed light on how to manage switches on course. In conclusion, this application of causal machine learning on EHR demonstrates utility in modeling dynamic, heterogeneous treatment effects that cannot be evaluated precisely using randomized clinical trials.

Use of a Mylar filter to eliminate vacuum ultraviolet pulse pileup in low-energy x-ray measurements

We describe a method to reduce vacuum ultraviolet (VUV) pulse pileup (PPU) in x-ray pulse-height Silicon Drift Detector (SDD) signals. An Amptek FAST SDD, with C1 (Si₃N₄) window, measures bremsstrahlung emitted from PFRC-2 plasma to extract the electron temperature (T_e) and density (n_e). The C1 window has low transmissivity for photons with energy below 200 eV though will transmit some VUV and soft x-ray photons, which PFRC-2 plasmas abundantly emit. Multi-VUV-photon PPU contaminates the interpretation of x rays with energy > 100 eV, particularly in a low-energy exponential tail. The predicted low transmissivity of ∼1 μm thick Mylar [polyethylene terephthalate (PET)] to photons of energy <100 eV led to the selection of Mylar as the candidate filter to reduce VUV PPU. Experiments were conducted on an x-ray tube with a graphite target and on a quasi-Maxwellian tenuous plasma (n_e ∼ 10⁹ cm^-3) with effective temperatures reaching 1500 eV. A Mylar filter thickness of 850 nm is consistent with the results. The Mylar-filter-equipped SDD was then used on the PFRC-2 plasma, showing a substantial reduction in the low-energy x-ray signal, supporting our hypothesis of the importance of VUV PPU. We describe the modeling and experiments performed to characterize the effect of the Mylar filter on SDD measurements.

A diagnostic to measure neutral-atom density in fusion-research plasmas

A femtosecond two-photon-absorption laser-induced-fluorescence (TALIF) diagnostic was designed, installed, and operated on the Princeton-Field-Reversed Configuration-2 device to provide non-invasive measurements of the time and spatially resolved neutral-atom densities in its plasmas. Calibration of the H^o density was accomplished by comparison with Kr TALIF. Measurements on plasmas formed of either H₂ or Kr fill gases allowed examination of nominally long and short ionization mean-free-path regimes. With multi-kW plasma heating and H₂ fill gas, a spatially uniform H^o density of order 10¹⁷ m^-3 was measured with better than ±2 mm and 10 µs resolution. Under similar plasma conditions but with Kr fill gas, a 3-fold decrease in the in-plasma Kr density was observed.

Evaluation of a collisional radiative model for electron temperature determination in hydrogen plasma

A collisional-radiative (CR) model that extracts the electron temperature, T_e, of hydrogen plasmas from Balmer-line-ratio measurements is examined for the plasma electron density, n_e, and T_e ranges of 10¹⁰-10¹⁵ cm^-3 and 5-500 eV, respectively. The CR code, developed and implemented in Python, has a forward component that computes the densities of excited states up to n = 15 as functions of T_e, n_e, and the molecular-to-atomic neutral ratio r(H₂/H). The backward component provides n_e and r(H₂/H) as functions of the Balmer ratios to predict the T_e. The model assumes Maxwellian electrons. The density profiles of the electrons and of the molecular and atomic hydrogen neutrals are shown to be of great importance, as is the accuracy of the line-ratio measurement method.

Simulating single-particle dynamics in magnetized plasmas: The RMF code

The RMF (Rotating Magnetic Field) code is designed to calculate the motion of a charged particle in a given electromagnetic field. It integrates Hamilton's equations in cylindrical coordinates using an adaptive predictor-corrector double-precision variable-coefficient ordinary differential equation solver for speed and accuracy. RMF has multiple capabilities for the field. Particle motion is initialized by specifying the position and velocity vectors. The six-dimensional state vector and derived quantities are saved as functions of time. A post-processing graphics code, XDRAW, is used on the stored output to plot up to 12 windows of any two quantities using different colors to denote successive time intervals. Multiple cases of RMF may be run in parallel and perform data mining on the results. Recent features are a synthetic diagnostic for simulating the observations of charge-exchange-neutral energy distributions and RF grids to explore a Fermi acceleration parallel to static magnetic fields.

Pregabalin for Recurrent Seizures in Critical Illness: A Promising Adjunctive Therapy, Especially for cyclic Seizures

BACKGROUND

Pregabalin (PGB) is an effective adjunctive treatment for focal epilepsy and acts by binding to the alpha2-delta subunit of voltage-gated calcium channels to reduce excitatory neurotransmitter release. Limited data exist on its use in the neurocritical care setting, including cyclic seizures-a pattern of recurrent seizures occurring at nearly regular intervals. Although the mechanism underpinning cyclic seizures remains elusive, spreading excitation linked to spreading depolarizations may play a role in seizure recurrence and periodicity. PGB has been shown to increase spreading depolarization threshold; hence, we hypothesized that the magnitude of antiseizure effect from PGB is more pronounced in patients with cyclic versus noncyclic seizures in a critically ill cohort with recurrent seizures.

METHODS

We conducted a retrospective case series of adults admitted to two academic neurointensive care units between January 2017 and March 2019 who received PGB for treatment of seizures. Data collected included demographics, etiology of brain injury, antiseizure medications, and outcome. Continuous electroencephalogram recordings 48 hours before and after PGB administration were reviewed by electroencephalographers blinded to the administration of antiseizure medications to obtain granular data on electrographic seizure burden. Cyclic seizures were determined quantitatively (i.e., < 50% variation of interseizure intervals for at least 50% of consecutive seizures). Coprimary outcomes were decrease in hourly seizure burden in minutes and decrease in seizure frequency in the 48 hours after PGB initiation. We used nonparametric tests for comparison of seizure frequency and burden and segmented linear regression to assess PGB effect.

RESULTS

We included 16 patients; the median age was 69 years, 11 (68.7%) were women, three (18.8%) had undergone a neurosurgical procedure, and five (31%) had underlying epilepsy. All seizures had focal onset; ten patients (62.5%) had cyclic seizures. The median hourly seizure burden over the 48 hours prior to PGB initiation was 1.87 min/hour (interquartile range 1.49-8.53), and the median seizure frequency was 1.96 seizures/hour (interquartile range 1.06-3.41). In the 48 hours following PGB (median daily dose 300 mg, range 75-300 mg), the median number of seizures per hour was reduced by 0.80 seizures/hour (95% confidence interval 0.19-1.40), whereas the median hourly seizure burden decreased by 1.71 min/hour (95% confidence interval 0.38-3.04). When we compared patients with cyclic versus noncyclic seizures, there was a relative decrease in hourly seizure frequency (- 86.7% versus - 2%, p = 0.04) and hourly seizure burden (- 89% versus - 7.8%, p = 0.03) at 48 hours.

CONCLUSIONS

PGB was associated with a relative reduction in seizure burden in neurocritically ill patients with recurrent seizures, especially those with cyclic seizures, and may be considered in the therapeutic arsenal for refractory seizures. Whether this effect is mediated via modulation of spreading depolarization requires further study.

Cardiac arrest: An interdisciplinary scoping review of clinical literature from 2020

Objectives

The Interdisciplinary Cardiac Arrest Research Review (ICARE) group was formed in 2018 to conduct an annual search of peer-reviewed literature relevant to cardiac arrest. Now in its third year, the goals of the review are to highlight annual updates in the interdisciplinary world of clinical cardiac arrest research with a focus on clinically relevant and impactful clinical and population-level studies from 2020.

Methods

A search of PubMed using keywords related to clinical research in cardiac arrest was conducted. Titles and abstracts were screened for relevance and sorted into 7 categories: Epidemiology & Public Health Initiatives; Prehospital Resuscitation, Technology & Care; In-Hospital Resuscitation & Post-Arrest Care; Prognostication & Outcomes; Pediatrics; Interdisciplinary Guidelines & Reviews; and a new section dedicated to the coronavirus disease 2019 (COVID-19) pandemic. Screened manuscripts underwent standardized scoring of methodological quality and impact on the respective fields by reviewer teams lead by a subject matter expert editor. Articles scoring higher than 99 percentiles by category were selected for full critique. Systematic differences between editors' and reviewers' scores were assessed using Wilcoxon signed-rank test.

Results

A total of 3594 articles were identified on initial search; of these, 1026 were scored after screening for relevance and deduplication, and 51 underwent full critique. The leading category was Prehospital Resuscitation, Technology & Care representing 35% (18/51) of fully reviewed articles. Four COVID-19 related articles were included for formal review that was attributed to a relative lack of high-quality data concerning cardiac arrest and COVID-19 specifically by the end of the 2020 calendar year. No significant differences between editor and reviewer scoring were found among review articles (P = 0.697). Among original research articles, section editors scored a median 1 point (interquartile range, 0-3; P < 0.01) less than reviewers.

Conclusions

Several clinically relevant studies have added to the evidence base for the management of cardiac arrest patients including methods for prognostication of neurologic outcome following arrest, airway management strategy, timing of coronary intervention, and methods to improve expeditious performance of key components of resuscitation such as chest compressions in adults and children.

Ultra-early serum concentrations of neuronal and astroglial biomarkers predict poor neurological outcome after out-of-hospital cardiac arrest-a pilot neuroprognostic study

OBJECTIVES

To assess ultra-early neuroprognostic significance of GFAP, NF-L, UCH-L1, tau, and S100B concentrations, change trajectory, and combination profile after Out-of-Hospital Cardiac Arrest (OHCA).

METHODS

Prospective enrollment of 22 OHCA and 10 control patients at an academic tertiary care center between May 1, 2017 and January 28, 2020. Blood was collected within one hour of return of spontaneous circulation (ROSC) (H0), at hours 6 (H6), 12, 18, 24, and daily or until discharge or death. Biomarker concentrations, multifactor score, and trajectory change were assessed and compared to final neurologic status (good vs poor Cerebral Performance Category; CPC 1-2 vs CPC 3-5, respectively).

RESULTS

10 patients had good and 12 had poor neurologic outcomes. Poor outcome patients had higher biomarker concentrations and combined biomarker scores at early time points. The earliest significant difference between good and poor outcome patients' serum biomarkers were at H12 for GFAP (good median: 425 pg/mL [IQR:370-630] vs poor: 5954[1712-65,055] pg/mL; p < 0.001), H12 for NF-L (64[41-69] vs 898[348-1990] pg/mL; p < 0.001), H0 for Tau (31[8-51] vs 124[53-238] pg/mL; p = 0.025), H0 for UCH-L1 (898[375-1600] vs 2475[1898-4098] pg/mL; p = 0.008), and H6 for S100B (123[70-290] vs 895[360-1199] pg/mL; p = 0.002). Four biomarker composite scores differed by H12 (78.03[52.03-111.25] vs 749 [198.46-4870.63] pg/mL; p = 0.003). Machine-learning approach also identified that four-marker score trajectory group memberships are in concordance with patient outcome.

CONCLUSIONS

Ultra-early serial serum concentrations of neuronal and astroglial biomarkers may be of neuroprognostic significance following OHCA.

Abstract 042: Do Disparities In Cardiovascular Comorbidities Account For Excess Covid-19 Morbidity And Mortality In African Americans?

Introduction: COVID-19 incidence, severity, and death in African Americans (AA) has been reported to markedly exceed those of White Americans (WA), but the epidemiologic basis for this is unclear.

Hypothesis: We hypothesize that AA have an excess of comorbid conditions compared to WA accounting for the disparity in COVID-19 infection and death.

Methods: We examined 67,094 COVID-19 cases with laboratory-confirmed COVID-19 and compared them to 135,188 controls (2:1 match by age, sex, and zip code) representing a state-wide sample of healthcare recipients from the ‘OneFlorida’ research consortium through August 3, 2020. We assessed the prevalence of preexisting comorbid conditions (e.g. cardiovascular disease, cancer), behavioral risk factors, and health outcomes in the electronic health records of COVID-19 cases compared to controls.

Results: Cases included 25,443 (37.9%) WA, 11,709 (17.5%) AA, and 16,119 (24%) Hispanic Americans (HA). Among cases, there was a significant increase in the prevalence of several cardiovascular comorbidities in AA vs. WA, such as hypertension, diabetes, heart failure, and stroke, but not for common cancers, liver disease, and COPD (Table 1). Likewise, smoking and BMI were higher in AA. Similar disparities were also appreciated in matched controls. Compared to WA, AA and HA had higher odds of becoming infected with COVID-19 (Unadjusted OR, 1.08; CI [1.05-1.11] and OR, 1.17; [1.15-1.2]) respectively. The prevalence of severe COVID-19 outcomes (intubation and death) was higher in AA (3.6 and 2.7%) than WA (2.5% and 2.3%) or HA (1.3 and 1.4%), respectively.

Conclusions: Excess comorbidities for cardiometabolic diseases are present in this population-based sample of COVID-19 cases and controls. Careful mediation analyses will determine whether these differences in cardiovascular comorbidities alone account for disparities in COVID-19 in AA patients. Such data would be important to identify high-risk subgroups benefitting from enhanced preventive and early therapeutic interventions.

Diagnostic Performance of High-Sensitivity Cardiac Troponin T Strategies and Clinical Variables in a Multisite US Cohort

BACKGROUND

European data support the use of low high-sensitivity troponin (hs-cTn) measurements or a 0/1-hour (0/1-h) algorithm for myocardial infarction to exclude major adverse cardiac events (MACEs) among patients in the emergency department with possible acute coronary syndrome. However, modest US data exist to validate these strategies. This study evaluated the diagnostic performance of an initial hs-cTnT measure below the limit of quantification (LOQ: 6 ng/L), a 0/1-h algorithm, and their combination with history, ECG, age, risk factors, and initial troponin (HEART) scores for excluding MACE in a multisite US cohort.

METHODS

A prospective cohort study was conducted at 8 US sites, enrolling adult patients in the emergency department with symptoms suggestive of acute coronary syndrome and without ST-elevation on ECG. Baseline and 1-hour blood samples were collected, and hs-cTnT (Roche; Basel, Switzerland) was measured. Treating providers blinded to hs-cTnT results prospectively calculated HEART scores. MACE (cardiac death, myocardial infarction, and coronary revascularization) at 30 days was adjudicated. The proportion of patients with initial hs-cTnT measures below the LOQ and risk according to a 0/1-h algorithm was determined. The negative predictive value (NPV) was calculated for both strategies when used alone or with a HEART score.

RESULTS

Among 1462 participants with initial hs-cTnT measures, 46.4% (678 of 1462) were women and 37.1% (542 of 1462) were Black with an age of 57.6±12.9 (mean±SD) years. MACEs at 30 days occurred in 14.4% (210 of 1462) of participants. Initial hs-cTnT measures below the LOQ occurred in 32.8% (479 of 1462), yielding an NPV of 98.3% (95% CI, 96.7-99.3) for 30-day MACEs. A low-risk HEART score with an initial hs-cTnT below the LOQ occurred in 20.1% (294 of 1462), yielding an NPV of 99.0% (95% CI, 97.0-99.8) for 30-day MACEs. A 0/1-h algorithm was complete in 1430 patients, ruling out 57.8% (826 of 1430) with an NPV of 97.2% (95% CI, 95.9-98.2) for 30-day MACEs. Adding a low HEART score to the 0/1-h algorithm ruled out 30.8% (441 of 1430) with an NPV of 98.4% (95% CI, 96.8-99.4) for 30-day MACEs.

CONCLUSIONS

In a prospective multisite US cohort, an initial hs-cTnT below the LOQ combined with a low-risk HEART score has a 99% NPV for 30-day MACEs. The 0/1-h hs-cTnT algorithm did not achieve an NPV >99% for 30-day MACEs when used alone or with a HEART score. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02984436.

Cardiac arrest: An interdisciplinary review of the literature from 2018

OBJECTIVES

The Interdisciplinary Cardiac Arrest Research Review (ICARE) group was formed in 2018 to conduct a systematic annual search of peer-reviewed literature relevant to cardiac arrest (CA). The goals of the review are to illustrate best practices and help reduce knowledge silos by disseminating clinically relevant advances in the field of CA across disciplines.

METHODS

An electronic search of PubMed using keywords related to CA was conducted. Title and abstracts retrieved by these searches were screened for relevancy, separated by article type (original research or review), and sorted into 7 categories. Screened manuscripts underwent standardized scoring of overall methodological quality and importance. Articles scoring higher than 99 percentiles by category-type were selected for full critique. Systematic differences between editors and reviewer scores were assessed using Wilcoxon signed-rank test.

RESULTS

A total of 9119 articles were identified on initial search; of these, 1214 were scored after screening for relevance and deduplication, and 80 underwent full critique. Prognostication & Outcomes category comprised 25% and Epidemiology & Public Health 17.5% of fully reviewed articles. There were no differences between editor and reviewer scoring.

CONCLUSIONS

The total number of articles demonstrates the need for an accessible source summarizing high-quality research findings to serve as a high-yield reference for clinicians and scientists seeking to absorb the ever-growing body of CA-related literature. This may promote further development of the unique and interdisciplinary field of CA medicine.

Health Impact of Hurricanes Irma and Maria on St Thomas and St John, US Virgin Islands, 2017-2018

Objectives. To assess the health impact of Hurricane Irma and Hurricane Maria on St Thomas, US Virgin Islands.Methods. We collected data from interviews conducted 6 and 9 months after the hurricanes, a review of 597 randomly selected emergency department (ED) encounters, and administrative records from 10 716 ED visits 3 months before, between, and 3 months after the hurricanes.Results. Informants described damaged hospital infrastructure, including flooding, structural damage, and lost staff. The greatest public health impact was on the elderly and persons with chronic diseases. In the setting of loss of the electronic medical record system, ED chart reviews were limited by problems with missing data. ED administrative data demonstrated that posthurricane patients, compared with prehurricane patients, were older and had less severe complaints. There was a significant increase in patients being seen for diabetes-related and respiratory complaints, especially asthma. Suboptimal recordkeeping for medical evacuees limited the ability to assess outcomes for patients with severe illnesses.Conclusions. Hurricanes Irma and Maria caused major disruptions to health care on St Thomas. Emphasis should be given to building a resilient health care system that will optimally respond to future hurricanes.

Public perception towards bystander cardiopulmonary resuscitation

Objective

Bystander cardiopulmonary resuscitation (CPR) after out-of-hospital cardiac arrest (OHCA) improves survival and neurological outcomes. Nonetheless, many OHCA patients do not receive bystander CPR during a witnessed arrest. Our aim was to identify potential barriers to bystander CPR.

Methods

Participants at CPR training events conducted in the USA between February and May 2018 answered a 14-question survey prior to training. Respondents were asked about their overall comfort level performing CPR, and about potential concerns specific to performing CPR on a middle-aged female, a geriatric male, and male and female adolescent patients. Open-ended responses were analysed qualitatively by categorising responses into themes.

Results

Of the 677 participants, 582 (86.0%) completed the survey, with 509 (88.1%) between 18 and 29 years of age, 341 (58.6%) without prior CPR training and 556 (96.0%) without prior CPR experience. Across all four scenarios of patients in cardiac arrest, less than 65% of respondents reported that they would be ‘Extremely Likely’ (20.6%–29.1%) or ‘Moderately Likely’ (26.9%–34.8%) to initiate CPR. The leading concerns were ‘causing injury to patient’ for geriatric (n=193, 63.1%), female (n=51, 20.5%) and adolescent (n=148, 50.9%) patients. Lack of appropriate skills was the second leading concern when the victim was a geriatric (n=41, 13.4%) or adolescent (n=68, 23.4%) patient, whereas for female patients, 35 (14.1%) were concerned about exposing the patient or the patient’s breasts interfering with performance of CPR and 15 (6.0%) were concerned about being accused of sexual assault. Significant differences were observed in race, ethnicity and age regarding the likelihood of starting to perform CPR on female and adolescent patients.

Conclusions

Participants at CPR training events have multiple concerns and fears related to performing bystander CPR. Causing additional harm and lack of skills were among the leading reservations reported. These findings should be considered for improved CPR training and public education.

Patient, Neighborhood, and Spatial Determinants of Out-of-Hospital Cardiac Arrest Outcomes Throughout the Chain of Survival: A Community-Oriented Multilevel Analysis

Objective: Global and national trends of out-of-hospital cardiac arrest (OHCA) have been examined; however, geographic variation and socioeconomic disparities of OHCA outcomes in the community setting are less understood. We developed and tested a replicable, community-oriented assessment strategy aimed to identify spatial variations in OHCA outcomes using socioeconomic, prehospital, and in-hospital factors. Methods: Emergency medical service (EMS) records of adult, non-traumatic OHCA within Alachua County, FL (2012-2017) were retrospectively reviewed and matched to corresponding medical records at the University of Florida (UF). Incidence of cardiac arrest was geocoded to census tracts and connected to U.S. census socioeconomic attribute data. Primary outcomes include survival to emergency department (ED), hospital admission, discharge, and discharge to home. Multilevel mixed-effects logistic regression models were developed to assess sub-county geographic variance, probabilities of survival, and prehospital risk factors. Getis-Ord Gi statistic and Moran's I-test was applied to assess spatial clustering in outcome survival rates. Results: Of the 1562 OHCA cases extracted from EMS records, 1,335 (85.5%) were included with 372 transported to study site. Predicted probability of survival to ED was 57.0% (95CI: 51.3-62.3%). Of transported cases to study site ED, predicted probabilities of survival was to 41.7% (95CI: 36.1-47.6%) for hospital admission, 16.1% (95CI: 10.7-23.5%) for hospital discharge, and 7.1% (95CI: 3.7-13.3%) for home discharge. Census tracts accounted for significant variability in survival to ED (p < 0.001), discharge (p = 0.031), and home discharge outcomes (p = 0.036). There was no significant geographic variation in survival to admission outcome. Neighborhood-level factors significantly improved model fit for survival to ED, discharge, and discharge home outcomes. Multiple modifiable patient- and neighborhood-level variables of interest were identified, including rural-urban differences. Conclusion: We identified important geographic disparities that exist in OHCA outcomes at the community level. By using a replicable schematic, this variation can be explained through community-oriented modifiable socioeconomic and prehospital factors.

The Association between Physical Activity and Metabolic Syndrome in Older Adults with Obesity

BACKGROUND

Physical activity reduces the likelihood of developing metabolic syndrome (MetS). However, the association between different physical activity levels and MetS remains unclear in older adults with obesity.

METHODS

This cross-sectional study used four waves of data (2007-2008, 2009-2010, 2011-2012, 2013-2014) from two datasets: The National Health and Nutrition Examination Survey and United Sates Department of Agriculture's Food Patterns Equivalents Database. The sample included adults 60+ years of age (n= 613) with obesity who had physical activity and MetS data. Physical activity was assessed using the Global Physical Activity Questionnaire and categorized into three physical activity levels (low, medium, and high); and medium or high physical activity levels are aligned with or exceed current physical activity recommendations. Participants were classified as having MetS using a commonly agreed upon definition. Multiple logistic regression models examined the association between the three physical activity levels and MetS risk factors and MetS. All analyses adjusted for potential confounding variables and accounted for complex sampling.

RESULTS

Of 613 respondents, 72.1% (n=431) were classified as having MetS, and 44.3% (n = 263) had not met physical activity recommendations. Participants with high levels of physical activity had a lower risk of MetS (OR = 0.31, 95%CI: 0.13, 0.72) and more healthful levels of high-density lipoprotein cholesterol (OR = 0.39, 95%CI: 0.18, 0.84), blood pressure (OR = 0.39, 95%CI: 0.20, 0.77), fasting glucose (OR = 0.34, 95%CI: 0.15, 0.78) than participants categorized as having low physical activity.

CONCLUSIONS

Physical activity is associated with lower risk of MetS only for participants with the highest level of physical activity, which suggests that physical activity dosage is important to reduce MetS risk in older adults with obesity.

Relationship between Diet Quality, Physical Activity and Health-Related Quality of Life in Older Adults: Findings from 2007-2014 National Health and Nutrition Examination Survey

BACKGROUND

A growing body of research shows that diet quality and physical activity (PA) are associated with health-related quality of life (HRQOL). However, no study to date has assessed this association using the Healthy Eating Index-2015 as a measure of diet quality. Furthermore, few studies have examined the association between PA dose and HRQOL among a nationally representative sample of older adults.

OBJECTIVES

To investigate the relationship between diet quality, physical activity, and HRQOL.

DESIGN

A cross-sectional analysis was conducted using data obtained from 5,311 adults aged 60+ years who took part in the National Health and Nutrition Examination Survey between 2007 and 2014.

MEASUREMENTS

HRQOL was assessed by general health status, and number of physically unhealthy days, mentally unhealthy days, and inactive days in past 30 days. Diet quality was assessed by the Healthy Eating Index-2015 using data generated by two 24-hour dietary recalls. PA was measured by the Global Physical Activity Questionnaire. Multivariate logistic/or linear regression models were used to examine the association between diet quality, PA and HRQOL controlling for confounders and accounting for complex sampling.

RESULTS

Approximately half of the participants (55.2%) were women, 45.1% met current PA recommendations, 65% had less healthful diets according to the Healthy Eating Index-2015. Diet quality was associated with HROQL. For every 1-point diet quality score increase, the likelihood of respondents rating their general health as being excellent/good increased by 3% (OR=1.03, 95%CI: 1.02, 1.04), and number of inactive days (β =-0.03, 95%CI: -0.05, 0.00) and mental unhealthy days (β =-0.03, 95%CI: -0.05, -0.01) declined by 0.03 days. PA was associated with all HROQL measures and respondents with high PA levels reported better general health (OR=3.53, 95%CI: 2.69, 4.63), fewer inactive days (β =-1.53, 95%CI: -2.11, -0.95), fewer physical unhealthy days (β =-1.88, 95%CI: -2.74, -1.02) than individuals with low PA levels but not fewer mentally unhealthy days.

CONCLUSIONS

Among older adults in this study, eating a healthier diet and being physically active were associated with better general health and reporting fewer physical unhealthy days and inactive days. Study results provide valuable information that could inform policies, programs and interventions designed to improve HRQOL in older adults and reduce potentially preventable health disparities.

Incidence and outcomes of bloodstream infections among hematopoietic cell transplant recipients from species commonly reported to be in over-the-counter probiotic formulations

BACKGROUND

Probiotic supplementation has been promoted for numerous health conditions; however, safety in immunosuppressed patients is unknown. We evaluated bloodstream infections (BSIs) caused by common probiotic organisms in hematopoietic cell transplant recipients.

METHODS

All blood culture (BC) results from a cohort of hematopoietic cell transplant recipients transplanted at Fred Hutchinson Cancer Research Center in Seattle, Washington, between 2002 and 2011 were reviewed. Patients with at least 1 positive BC for common probiotic organisms (Lactobacillus species, Bifidobacterium species, Streptococcus thermophilus, and Saccharomyces species) within 1 year post hematopoietic cell transplantation (HCT) were considered cases. Data were collected from center databases, which contain archived laboratory data, patient demographics, and clinical summaries.

RESULTS

A total of 19/3796 (0.5%) patients developed a BSI from one of these organisms within 1 year post HCT; no Bifidobacterium species or S. thermophilus were identified. Cases had a median age of 49 years (interquartile range [IQR]: 39-53), and the majority were allogeneic hematopoietic cell transplant recipients (14/19, 74%). Most positive BCs were Lactobacillus species (18/19) and occurred at a median of 84 days (IQR: 34-127) post transplant. The incidence rate of Lactobacillus bacteremia was 1.62 cases per 100,000 patient-days; the highest rate occurred within 100 days post transplant (3.3 per 100,000 patient-days). Eight patients (44%) were diagnosed with acute graft-versus-host disease of the gut prior to the development of bacteremia. No mortality was attributable to any of these infections.

CONCLUSION

Organisms frequently incorporated in available over-the-counter probiotics are infrequent causes of bacteremia after HCT. Studies evaluating the use of probiotics among high-risk patients are needed.

Examining trends in the treatment of ureterocele yields no definitive solution

INTRODUCTION

The surgical management of ureteroceles is extremely variable. Some have hypothesized that if these patients were treated with 'definitive' staged surgical intervention, the need for further revision surgery would be eliminated.

OBJECTIVE

The present study sought to determine if the rate of revision surgery differed among patients who have undergone different surgical approaches for the ureterocele complex.

STUDY DESIGN

A large retrospective chart review was conducted, identifying all patients having undergone ureterocele surgery at a single institution over the past 41 years. The cohort was divided into four groups based on surgical approach: upper tract approach (UTA), lower tract reconstruction (LTR), simultaneous upper and lower tract approach (ULTA), and staged lower tract reconstruction (SLTR). Demographics, the presence of preoperative/postoperative VUR, postoperative morbidity and the need for revision surgery were compared using the Chi- squared test, Fisher's exact test, Kruskal-Wallis test, Mann-Whitney U test (Bonferroni correction), logistic regression modeling and survival analyses (Kaplan-Meier and Cox proportional Hazards regression with unplanned revision operation as the outcome event).

RESULTS

Between 1969 and 2010, 180 patients were identified as having undergone surgical management of ureteroceles, of which 120 had complete demographic data available for analysis. The median age at the time of initial surgical intervention was 5.8 months and the majority of patients (83.3%) were female. The median follow-up was 33.1 months. Surgical management was as follows: 18 (15.0%) patients underwent UTA, 47 (39.2%) underwent LTR, 23 (19.2%) underwent ULTA, and 32 (26.6%) underwent SLTR. Among these groups, the only difference in median age was between the LTR and SLTR groups (6.3 months vs 3.7 months, P=0.012). Additional revision surgery was required in: nine (50.0%) of UTA, ten (21.3%) of LTR, four (17.4%) of ULTA, and three (9.4%) of SLTR. The only statistically significant difference in unplanned revision surgery was noted in the UTA group versus each of the other groups with VUR as the predominant indication (88.9%). The likelihood of requiring revision surgery in comparison to the SLTR group was significantly increased in the UTA group (OR 9.67, CI 2.15-43.56), but not in the LTR (OR 2.61, CI 0.66-10.37) or the ULTA group (OR 2.04, CI 0.41-10.13). Obstruction, recurring UTIs and VUR were the main indications for revision surgery overall.

DISCUSSION

There is a large body of literature examining the surgical management of ureteroceles. It most recently primarily focuses on an endoscopic approach to the lower tract. The present retrospective review examined the need for re-operative intervention by comparing four different surgical approaches, and found that there is no panacea. Although heminephrectomy (UTA) was a definitive procedure in some patients without reflux at presentation, many who underwent heminephrectomy, went on to require later bladder surgery for either recurrent UTI or persistent reflux. The present study has multiple limitations. Although VUR was an indication for revision surgery in the early part of the series, the current treatment of VUR is not necessarily as stringent. In addition, no distinction was made between an orthotopic or ectopic ureterocele, although some authors have reported differing outcomes in these two groups. However, it is felt that given the large data set of a relatively uncommon condition, the lack of superiority of one approach is apparent.

CONCLUSION

There is no definitive surgical repair for the ureterocele complex. All groups except UTA had statistically similar rates of revision surgery. The widespread variability in current management echoes the lack of one superior approach found in this comprehensive series.

Formation of field-reversed-configuration plasma with punctuated-betatron-orbit electrons

We describe ab initio, self-consistent, 3D, fully electromagnetic numerical simulations of current drive and field-reversed-configuration plasma formation by odd-parity rotating magnetic fields (RMF{o}). Magnetic-separatrix formation and field reversal are attained from an initial mirror configuration. A population of punctuated-betatron-orbit electrons, generated by the RMF{o}, carries the majority of the field-normal azimuthal electrical current responsible for field reversal. Appreciable current and plasma pressure exist outside the magnetic separatrix whose shape is modulated by the RMF{o} phase. The predicted plasma density and electron energy distribution compare favorably with RMF{o} experiments.

Formation of collisionless high-beta plasmas by odd-parity rotating magnetic fields

Odd-parity rotating magnetic fields (RMFo) applied to mirror-configuration plasmas have produced average electron energies exceeding 200 eV at line-averaged electron densities of approximately 10(12) cm-3. These plasmas, sustained for over 10(3)tauAlfven, have low Coulomb collisionality, vc* triple bond L/lambdaC approximately 10(-3), where lambdaC is the Coulomb scattering mean free path and L is the plasma's characteristic half length. Divertors allow reduction of the electron-neutral collision frequency to values where the RMFo coupling indicates full penetration of the RMFo to the major axis.

Onset and saturation of ion heating by odd-parity rotating magnetic fields in a field-reversed configuration

Heating of figure-8 orbit ions by odd-parity rotating magnetic fields (RMF(O)) applied to an elongated field-reversed configuration (FRC) is investigated. The largest energy gain occurs at resonances (s congruent to omega(R)/omega) of the RMF(O) frequency, omega(R), with the figure-8 orbital frequency, omega, and is proportional to s2 for s-even resonances and to s for s-odd resonances. The threshold for the transition from regular to stochastic orbits explains both the onset and saturation of heating. The FRC magnetic geometry lowers the threshold for heating below that in the tokamak by an order of magnitude.

A prospective assessment of mortality in chronic spinal cord injury

STUDY DESIGN

Prospective mortality study.

OBJECTIVE

To assess the relationship between comorbid medical conditions and other health-related factors to mortality in chronic spinal cord injury (SCI).

SETTING

Boston, MA, USA.

METHODS

Between 1994 and 2000, 361 males >/=1 year after injury completed a respiratory health questionnaire and underwent pulmonary function testing. Cause-specific mortality was assessed over a median of 55.6 months (range 0.33-74.4 months) through 12/31/2000 using the National Death Index.

RESULTS

At entry, mean (+/-SD) age was 50.6+/-15.0 years (range 23-87) and years since injury was 17.5+/-12.8 years (range 1.0-56.5). Mortality was elevated (observed/expected deaths=37/25.1; SMR=1.47; 95% CI=1.04-2.03) compared to US rates. Risk factors for death were diabetes (RR=2.62; 95% CI=1.19-5.77), heart disease (RR=3.66; 95% CI=1.77-7.78), reduced pulmonary function, and smoking. The most common underlying and contributing causes of death were diseases of the circulatory system (ICD-9 390-459) in 40%, and of the respiratory system in 24% (ICD-9 460-519).

CONCLUSIONS

These results suggest that much of the excess mortality in chronic SCI is related to potentially treatable factors. Recognition and treatment of cardiovascular disease, diabetes, and lung disease, together with smoking cessation may substantially reduce mortality in chronic SCI.

Benign metastasizing leiomyoma

Benign metastasizing leiomyoma is a rare clinical entity that has been described in several previous reports. Although the exact pathophysiology of the disease is unknown, two predominant theories exist: (1) metastasis from an existing leiomyoma (commonly seen with uterine leiomyoma) or (2) multicentric leiomyomatous growths rather than actual metastases. We present an interesting case in which several elements of the patient's history complicated the differential diagnosis.

Epithelioid hemangioendothelioma of the maxilla: case report and review of literature

Epithelioid Hemangioendothelioma (EH) is a rare, low-grade malignant vascular tumor, first defined as a soft tissue tumor by Enzinger and Weiss in 1982. The tumor was later reported in virtually all sites, including liver, lung, brain, and bone. The epithelioid neoplastic cells are of endothelial origin, staining positive for Factor VIII and CD-34. In our review of EH of bone medline literature, and including the present case report, a total of 73 cases were found. Forty-one (56%) patients had multifocal bone involvement and thirty-two (44%) patients had solitary EH of bone. Resection was the primary recommended treatment. Visceral involvement appears to affect prognosis and survival adversely. We report a case of EH of the maxilla, which occurred in a 32-year-old male.

Homogeneous preparation of fluorescent-derivatized insulin and its application to competitive chromatographic immunoassays

A homogeneously labeled insulin sample was prepared using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) as the fluorescent-labeling reagent, and this was successfully applied to a chromatographic immunoassay. This labeled insulin was prepared by tagging all the three amino groups with AQC. Both CE and chromatographic immunoassay experiments indicated that the prepared insulin still kept its immunoaffinity to its antibody. It was observed that appropriate concentrations of acetonitrile (ACN) were efficient in lowering the quenching of the fluorescent signal of tagged insulin, in keeping the dilute, tagged insulin in solution, and in improving its peak shape during a chromatographic immunoassay. The tagged insulin was found to be 20-400 times more sensitive than native insulin detected under ultraviolet detection conditions. A competitive chromatographic immunoassay system was set up and calibrated. The system was used for analyses of an insulin-spiked urine sample, with a 96% recovery obtained.

Homogeneous fluorescent derivatization of large proteins

A method of homogeneously derivatizing large proteins for highly sensitive analysis is described. Homogeneity of the derivative was realized by tagging all the free amino groups of proteins. With this method, alpha-chymotrypsinogen A, ovalbumin and bovine serum albumin were derivatized with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC). Prior to the derivatization, all the proteins were reduced and alkylated. After reacting the resulting unfolded proteins with excessive amounts of AQC, the samples were analyzed with matrix assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) to determine the derivatization degree. The results indicated that all three proteins had been, or had almost been, fully derivatized. HPLC and CE were used for characterizing these protein derivatives. Under the optimized fluorescence detection conditions, the detectability of the tagged proteins was 2400-6200 times better than that detected at UV 280 nm, 170-300 times better than detected at UV 214 nm, and 150-420 times better than measured with their native fluorescence.

Femtomole peptide mapping by derivatization, high-performance liquid chromatography, and fluorescence detection

A highly sensitive peptide mapping method using derivatization and fluorescence detection is described. Bovine cytochrome c was digested using a buffer compatible with the derivatization that followed. The derivatization was performed with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate. The peptide mapping of the tagged digest was conducted with both HPLC and capillary LC (CLC) systems. A capillary LC-electrospray ionization mass spectrometer (MS) was set up for measuring the molecular weights of the tagged peptides. Optimization was made of the conditions used for digestion, derivatization, and mapping. MS measurements of the tagged peptides suggested that there was only one derivatization product produced from all peptides (except one) and that all the identified peptides were fully tagged. Peptide mapping of the tagged digest reviews a larger number of peptides, covering almost the entire sequence. Peptide mapping of a 20 fmol amount of tagged digest was readily performed with the CLC system. By using derivatization and fluorescence detection, the sensitivity of peptide mapping could be improved 2000 times compared to that observed with uv detection of untagged peptides.

Compartment syndrome associated with lithotomy position and intermittent compression stockings

BACKGROUND

Compartment syndrome is a condition in which increased tissue pressure within a limited tissue space compromises the circulation and function of the contents of the space.

CASE

A 43-year-old black woman, para 3, had repair of a recurrent vesicovaginal fistula. She was placed in a low lithotomy position with thigh length sequential compression sleeves. The procedure lasted more than 5 hours. On postoperative day 1, she complained of pain in her right leg and foot. Compartment syndrome was diagnosed and emergency fasciotomy was done.

CONCLUSION

Gynecologists should be aware of the possibility of compartment syndrome during prolonged procedures with patients in the lithotomy position. Concomitant intermittent compression sleeves might further increase the risk. Early diagnosis and treatment of compression syndrome are essential to minimize long-term neurovascular morbidity.

Endoscopic retrograde cholangiopancreatography and the pancreas: when and why?

Historically, endoscopic retrograde cholangeopancreatography (ERCP) has played a unique role as a diagnostic and therapeutic modality for diseases of the pancreas. Despite the advent of new imaging techniques, ERCP continues to play a central role in the evaluation and treatment of pancreatitis of various causes. Endoscopic cholangiography and stenting remain mainstays in the palliation of inoperable obstructive jaundice in patients with cancer of the pancreas.

Pancreas divisum: endoscopic therapy

Pancreas divisum is a common congenital variation that can be associated with pancreatic disease. Symptomatic patients with divisum must be classified according to clinical presentation and morphologic findings. Response to endoscopic therapy is best in patients with ARP, of whom 75% benefit. Results in patients with chronic pancreatitis and pain but without objective pancreatitis are mixed, and patients should be carefully selected.

Voltage-gated sodium channel (SkM1) content in dystrophin-deficient muscle

The membrane cytoskeleton is increasingly considered as both an anchor and a functional modulator for ion channels. The cytoskeletal disruptions that occur in the absence of dystrophin led us to investigate the voltage-gated sodium channel (SkM1) content in the extensor digitorum longus (EDL) muscle of the dystrophin-deficient mdx mouse. Levels of SkM1 mRNA were determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). A C-terminal portion of the mouse-specific SkM1 alpha-subunit cDNA (mScn4a) was identified first. SkM1 mRNA levels were as abundant in mdx as in normal muscle, thus suggesting that the transcriptional rate of SkM1 remains unchanged in mdx muscle. However, SkMI density in the extrajunctional sarcolemma was shown to be significantly reduced in mdx muscle, using confocal immunofluorescence image analysis. This decrease was found to be associated with a reduction in the number of SkM1-rich fast-twitch IIb fibres in mdx muscle. In addition, lowered SkM1 sarcolemmal labelling was found in all mdx fibres regardless of their metabolic type. These results suggest the existence of a perturbation of SkM1 anchorage to the plasma membrane. Such an alteration is likely to be related to the 50% decrease in mdx muscle of the dystrophin-associated syntrophins, which are presumed to be involved in SkM1 anchorage. However, the moderate reduction in SkM1 density (-12.7%) observed in mdx muscle argues in favour of a non-exclusive role of syntrophins in SkM1 anchorage and suggests that other membrane-associated proteins are probably also involved.

Ion heating in the field-reversed configuration by rotating magnetic fields near the ion-cyclotron resonance

The trajectories of ions confined in a field-reversed configuration (FRC) equilibrium magnetic geometry and heated with a small-amplitude, odd-parity rotating magnetic field (RMF) have been studied with a Hamiltonian computer code. When the RMF frequency is in the ion-cyclotron range, explosive heating occurs. Higher-energy ions are found to have betatron-type orbits, preferentially localized near the FRC's midplane. These results are relevant to a compact magnetic-fusion-reactor design.

A carboxy-terminal alpha-helical segment in the rat skeletal muscle voltage-dependent Na+ channel is responsible for its interaction with the amino-terminus

Cytoplasmic segments of the adult rat skeletal muscle sodium channel alpha-subunit (rSkM1) comprise a major portion (approximately 40%) of the total protein and are involved in channel functions both general, such as inactivation, and isoform-specific, for example, protein kinase A modulation. Far ultraviolet circular dichroism measurements of synthetic peptides and overexpressed fusion proteins containing individual channel cytoplasmic segments suggest that cytoplasmic domains of rSkM1 contain ordered secondary structures even in the absence of adjoining transmembrane segments. Intrinsic fluorescence experiments with a nested set of carboxy-terminal deletion proteins confirm a specific interaction between the channel's amino- and carboxy-termini and identify residues 1716-1737 in the carboxy-terminus as the region that binds to the amino-terminus. Circular dichroism measurements suggest that this same region is organized as an alpha-helix and that electrostatic forces may contribute to this association. The interaction of the amino- and carboxy-termini is not accompanied by secondary structure changes detectable by circular dichroism spectroscopy, but a decrease in intrinsic fluorescence indicates that this association is accompanied by a change in the environment of Trp1617.

Nitrogen atom energy distributions in a hollow-cathode planar sputtering magnetron

Energy distributions of nitrogen atoms (N) in a hollow-cathode planar sputtering magnetron were obtained by use of optical emission spectroscopy. A characteristic line, N I 8216.3 A, well separated from molecular nitrogen emission bands, was identified. Jansson's nonlinear spectral deconvolution method, refined by minimization of chi(2)(w), was used to obtain the optimal deconvolved spectra. These showed nitrogen atom energies from 1 eV to beyond 500 eV. Based on comparisons with VFTRIM computer code results, it is proposed that the energetic N's are generated from N+2 ions after these ions are accelerated through the sheath and dissociatively reflect from the cathode.

Potential future clinical applications for the GPIIb/IIIa antagonist, abciximab in thrombosis, vascular and oncological indications

Abciximab (ReoPro) is a mouse-human chimeric monoclonal antibody Fab fragment of the parent murine monoclonal antibody 7E3, and was the first of these agents approved for use as adjunct therapy for the prevention of cardiac ischemic complications in patients undergoing percutaneous coronary intervention (PCI). Abciximab binds with high avidity to both the non-activated and activated form of the GPIIb/IIIa receptor of platelets, the major adhesion receptor involved in aggregation. Additional cardiovascular indications for abciximab are unstable angina, carotid stenting, ischemic stroke and peripheral vascular diseases. Abciximab also interacts with two other integrin receptors; the a av b b3 receptor, which is present in low numbers on platelets but in high density on activated endothelial and smooth muscle cells, and a aMb b2 integrin which is present on activated leukocytes. Cell types that express integrins GPIIb/IIIa and a av b b3 such as platelets, endothelial and tumor cells have been implicated in angiogenesis, tumor growth and metastasis. Since abciximab interacts with high avidity to integrins GPIIb/IIIa and a av b b3, it is reasonable to assume that it may possess anti-angiogenic properties in angiogenesis-related diseases, as well as anti-metastastatic properties in case of disseminating tumors expressing the target integrin receptors.

Identification of proteins electroblotted to polyvinylidene difluoride membrane by combined amino acid analysis and bioinformatics: An ABRF multicenter study

The ABRF amino acid analysis study evaluated the general utility of amino acid analysis (AAA) for identification of proteins after denaturing gel electrophoresis and electroblotting to polyvinylidene difluoride (PVDF) membrane.Thirty-eight participating laboratories analyzed a known control (ovalbumin, 5 microg applied to the gel) and either lysozyme or bovine serum albumin as unknown samples (1-, 5-, and 10-microg amounts applied to the gel). Analyses of the unknowns yielded average compositional errors of approximately 30%, 19%, and 18%, respectively, from the low, intermediate, and higher sample amounts; the ovalbumin control exhibited an approximately 17% average error. Compositional data were submitted to the ExPASy and PROPSEARCH Internet sites for protein identification.Without search parameter adjustments or restrictions, both computer programs provided identification of about 20%, 66%, and 74% of the data from the 1-, 5-, and 10-microg gel samples, respectively. Deleting problematic data (Gly, Met, and Pro) did not always facilitate protein identification. Incorporating control results into the ExPASy search increased identifications 2% to 10%, and restricting search parameters by species, isoelectric pH, and molecular weight increased identifications by more than 80%. Average amounts analyzed for correct identifications were approximately 0.4 microg, 1.8 microg, and 2.9 microg for the 1-, 5-, and 10-microg gel samples, respectively.The results support the efficacy of AAA in the low microgram and nanogram range for the identification of PVDF-immobilized proteins from two-dimensional gels.