Experimental Evidence of Plasmoids in High-β Magnetic Reconnection

Magnetic reconnection is a ubiquitous and fundamental process in plasmas by which magnetic fields change their topology and release magnetic energy. Despite decades of research, the physics governing the reconnection process in many parameter regimes remains controversial. Contemporary reconnection theories predict that long, narrow current sheets are susceptible to the tearing instability and split into isolated magnetic islands (or plasmoids), resulting in an enhanced reconnection rate. While several experimental observations of plasmoids in the regime of low-to-intermediate β (where β is the ratio of plasma thermal pressure to magnetic pressure) have been made, there is a relative lack of experimental evidence for plasmoids in the high-β reconnection environments which are typical in many space and astrophysical contexts. Here, we report strong experimental evidence for plasmoid formation in laser-driven high-β reconnection experiments.

Serum alarmins and the risk of incident interstitial lung disease in rheumatoid arthritis

OBJECTIVES

To quantify associations of serum alarmins with risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

Using serum collected at enrolment, three alarmins (interleukin [IL]-33, thymic stromal lymphopoietin [TSLP], and IL-25) were measured in a multicentre prospective RA cohort. ILD was classified using systematic medical record review. Cross-sectional associations of log-transformed (IL-33, TSLP) or quartile (IL-25) values with RA-ILD at enrolment (prevalent RA-ILD) were examined using logistic regression, while associations with incident RA-ILD developing after enrolment were examined using Cox proportional hazards. Covariates in multivariate models included age, sex, race, smoking status, RA disease activity score, and anti-cyclic citrullinated antibody positivity.

RESULTS

Of 2,835 study participants, 115 participants (4.1%) had prevalent RA-ILD at baseline and an additional 146 (5.1%) developed incident ILD. There were no associations between serum alarmin concentrations and prevalent ILD in unadjusted or adjusted logistic regression models. In contrast, there was a significant inverse association between IL-33 concentration and the risk of developing incident RA-ILD in unadjusted (HR 0.73 per log-fold increase; 95% CI 0.57-0.95; p= 0.018) and adjusted (HR 0.77; 95% CI 0.59-1.00, p= 0.047) models. No significant associations of TSLP or IL-25 with incident ILD were observed.

CONCLUSIONS

In this study, we observed a significant inverse association between serum IL-33 concentration and the risk of developing incident RA-ILD, but no associations with prevalent ILD. Additional investigation is required to better understand the mechanisms driving this relationship and how serum alarmin IL-33 assessment might contribute to clinical risk stratification in patients with RA.

A Narrowing Mortality Gap: Temporal Trends of Cause-Specific Mortality in a National Matched Cohort Study in US Veterans With Rheumatoid Arthritis

OBJECTIVE

To examine temporal trends in all-cause and cause-specific mortality in patients with rheumatoid arthritis (RA) in the Veterans Health Administration (VHA).

METHODS

We conducted a matched cohort study in the VHA from January 1, 2000 to December 31, 2017. Incident RA patients were matched up to 1:10 on age, sex, and VHA enrollment year to non-RA patients, then followed until death or end of study period. Cause of death was obtained from the National Death Index. Multivariable Cox regression models stratified by RA diagnosis years were used to examine trends in RA-related risk of all-cause and cause-specific mortality.

RESULTS

Among 29,779 incident RA patients (matched to 245,226 non-RA patients), 9,565 deaths occurred. RA patients were at increased risk of all-cause (adjusted hazard ratio [HRadj ] 1.23 [95% confidence interval (95% CI) 1.20-1.26]), cardiovascular (HRadj 1.19 [95% CI 1.14-1.23]), cancer (HRadj 1.19 [95% CI 1.14-1.24]), respiratory (HRadj 1.46 [95% CI 1.38-1.55]), and infection-related mortality (HRadj 1.59 [95% CI 1.41-1.80]). Interstitial lung disease was the cause of death most strongly associated with RA (HRadj 3.39 [95% CI 2.88-3.99]). Nearly 70% of excess deaths in RA were attributable to cardiopulmonary disease. All-cause mortality risk related to RA was lower among those diagnosed during 2012-2017 (HRadj 1.10 [95% CI 1.05-1.15]) compared to 2000-2005 (HRadj 1.31 [95% CI 1.26-1.36]), but still higher than for non-RA controls (P < 0.001). Cause-specific mortality trends were similar.

CONCLUSION

Excess RA-related mortality was driven by cardiovascular, cancer, respiratory, and infectious causes, particularly cardiopulmonary diseases. Although our findings support that RA-related mortality risk is decreasing over time, a mortality gap remains for all-cause and cause-specific mortality in RA.

Aortic Stenosis Risk in Rheumatoid Arthritis

Importance

Although an increased risk of ischemic cardiovascular disease has been associated with rheumatoid arthritis (RA), the risk of aortic stenosis (AS) is unknown.

Objective

To examine the risk of incident AS, aortic valve intervention, AS-related death, and risk factors for AS development in patients with RA.

Design, Setting, and Participants

This cohort study linked data from the Veterans Health Administration (VHA) and Centers for Medicare & Medicaid Services from 2000 to 2019. Patients with RA were matched by age, sex, and VHA enrollment year with up to 10 patients without RA. The cohort was followed until incident AS, aortic valve intervention, or death. Data were analyzed from August 23, 2022, to March 3, 2023.

Exposures

the primary exposure was the presence of RA, defined using validated RA algorithms.

Main Outcomes and Measures

Aortic stenosis was defined as a composite of inpatient or outpatient diagnoses, surgical or transcatheter aortic valve replacement, or AS-related death using diagnostic and procedural codes. Risk of AS development was assessed with multivariable Cox proportional hazards models adjusted for race, ethnicity, smoking status, body mass index, rurality, comorbidities, and health care use.

Results

The cohort included 73 070 patients with RA (64 008 [87.6%] males; mean [SD] age, 63.0 [11.9] years) matched with 639 268 patients without RA (554 182 [86.7%] males; mean [SD] age, 61.9 [11.7] years) and 16 109 composite AS outcomes that occurred over 6 223 150 person-years. The AS incidence rate was 3.97 (95% CI, 3.81-4.13) per 1000 person-years in patients with RA and 2.45 (95% CI, 2.41-2.49) per 1000 person-years in the control patients (absolute difference, 1.52 per 1000 person-years). Rheumatoid arthritis was associated with an increased risk of composite AS (adjusted hazard ratio [AHR], 1.48; 95% CI, 1.41-1.55), aortic valve intervention (AHR, 1.34; 95% CI, 1.22-1.48), and AS-related death (AHR, 1.26; 95% CI, 1.04-1.54).

Conclusions and Relevance

In this cohort study, RA was associated with a higher risk of developing AS and the subsequent risks of undergoing aortic valve intervention and suffering from AS-related death. Future studies are needed to confirm whether valvular heart disease, specifically AS, may be an overlooked cardiovascular disease complication in RA.

Multimorbidity Patterns and Rheumatoid Arthritis Disease Outcomes: Findings From a Multicenter, Prospective Cohort

OBJECTIVE

To determine whether unique multimorbidity patterns are associated with long-term rheumatoid arthritis (RA) disease severity.

METHODS

We conducted a cohort study within the Veterans Affairs Rheumatoid Arthritis registry. We applied previously derived multimorbidity patterns based on the presence of diagnostic codes for relevant conditions prior to enrollment using linked administrative data. Disease activity and functional status were assessed longitudinally up to 5 years after enrollment. The association of multimorbidity patterns with disease activity and functional status were assessed using generalized estimating equations models adjusting for relevant confounders.

RESULTS

We studied 2,956 participants, of which 88.2% were male, 76.9% reported white race, and 79.3% had a smoking history. Mental health and substance abuse (β 0.12 [95% confidence interval {CI} 0.00, 0.23]), cardiovascular (β 0.25 [95% CI 0.12, 0.38]), and chronic pain (β 0.21 [95% CI 0.11, 0.31]) multimorbidity were associated with higher Disease Activity Score in 28 joints (DAS28) scores. Mental health and substance abuse (β 0.09 [0.03, 0.15]), cardiovascular (β 0.11 [95% CI 0.04, 0.17]), and chronic pain multimorbidity (β 0.15 [95% CI 0.10, 0.20]) were also associated with higher Multidimensional Health Assessment Questionnaire (MDHAQ) scores. The metabolic pattern of multimorbidity was not associated with DAS28 or MDHAQ. The number of multimorbidity patterns present was highly associated with DAS28 and MDHAQ (P trend < 0.001), and patients with all four multimorbidity patterns had the highest DAS28 (β 0.59 [95% CI 0.36, 0.83]) and MDHAQ (β 0.27 [95% CI 0.16, 0.39]) scores.

CONCLUSION

Mental health and substance abuse, chronic pain, and cardiovascular multimorbidity patterns are associated with increased RA disease activity and poorer functional status. Identifying and addressing these multimorbidity patterns may facilitate achieving RA treatment targets.

Circulating Adipokines and Associations With Incident Cardiovascular Disease in Rheumatoid Arthritis

OBJECTIVE

To assess whether circulating levels of adiponectin, leptin, and fibroblast growth factor 21 (FGF-21) are associated with incident cardiovascular disease (CVD) in rheumatoid arthritis (RA).

METHODS

Adipokines were measured using banked enrollment serum from patients with RA and dichotomized above/below the median value. Incident CVD events (coronary artery disease [CAD], stroke, heart failure [HF] hospitalization, venous thromboembolism, CVD-related deaths) were identified using administrative data and the National Death Index. Covariates were derived from medical record, biorepository, and registry databases. Multivariable Cox models were generated to quantify associations between adipokine concentrations and CVD incidence. Five-year incidence rates were predicted.

RESULTS

Among 2,598 participants, 639 (25%) had at least 1 CVD event over 19,585 patient-years of follow-up. High adiponectin levels were independently associated with HF hospitalization (hazard ratio [HR] 1.39 [95% confidence interval (95% CI) 1.07-1.79], P = 0.01) and CVD-related death (HR 1.49 [95% CI 1.16-1.92], P = 0.002) but not with other CVD events. High leptin was independently associated with CVD-related death (HR 1.44 [95% CI 1.05-1.97], P = 0.02). High FGF-21 levels were independently associated with lower rates of CAD (HR 0.75 [95% CI 0.58-0.97], P = 0.03). In subgroup analyses, associations between high adiponectin and leptin levels with CVD-related death were driven by strong associations in nonobese patients.

CONCLUSION

Adipokines are associated with HF hospitalization and CVD-related death in patients with RA, with stronger associations in nonobese participants. These findings suggest that adipokines effectively predict clinically important outcomes in RA perhaps through an association with body composition and metabolic health. Further study is needed to determine whether adipokine measures might augment existing tools to identify RA patients at increased risk of CVD.

In situ calibration of charged particle spectrometers on the OMEGA Laser Facility using 241Am and 226Ra sources

Charged particle spectrometry is a critical diagnostic to study inertial-confinement-fusion plasmas and high energy density plasmas. The OMEGA Laser Facility has two fixed magnetic charged particle spectrometers (CPSs) to measure MeV-ions. In situ calibration of these spectrometers was carried out using ²⁴¹Am and ²²⁶Ra alpha emitters. The alpha emission spectrum from the sources was measured independently using surface-barrier detectors (SBDs). The energy dispersion and broadening of the CPS systems were determined by comparing the CPS measured alpha spectrum to that of the SBD. The calibration method significantly constrains the energy dispersion, which was previously obtained through the measurement of charged particle fusion products. Overall, a small shift of 100 keV was observed between previous and the calibration done in this work.

Phased plan for the implementation of the time-resolving magnetic recoil spectrometer on the National Ignition Facility (NIF)

The time-resolving magnetic recoil spectrometer (MRSt) is a transformative diagnostic that will be used to measure the time-resolved neutron spectrum from an inertial confinement fusion implosion at the National Ignition Facility (NIF). It uses a CD foil on the outside of the hohlraum to convert fusion neutrons to recoil deuterons. An ion-optical system positioned outside the NIF target chamber energy-disperses and focuses forward-scattered deuterons. A pulse-dilation drift tube (PDDT) subsequently dilates, un-skews, and detects the signal. While the foil and ion-optical system have been designed, the PDDT requires more development before it can be implemented. Therefore, a phased plan is presented that first uses the foil and ion-optical systems with detectors that can be implemented immediately-namely CR-39 and hDISC streak cameras. These detectors will allow the MRSt to be commissioned in an intermediate stage and begin collecting data on a reduced timescale, while the PDDT is developed in parallel. A CR-39 detector will be used in phase 1 for the measurement of the time-integrated neutron spectra with excellent energy-resolution, necessary for the energy calibration of the system. Streak cameras will be used in phase 2 for measurement of the time-resolved spectrum with limited spectral coverage, which is sufficient to diagnose the time-resolved ion temperature. Simulations are presented that predict the performance of the streak camera detector, indicating that it will achieve excellent burn history measurements at current yields, and good time-resolved ion-temperature measurements at yields above 3 × 10¹⁷. The PDDT will be used for optimal efficiency and resolution in phase 3.

High-yield magnetic recoil neutron spectrometer on the National Ignition Facility for operation up to 60 MJ

Recent progress at the National Ignition Facility (NIF), with neutron yields of order 1 × 10¹⁷, places new constraints on diagnostics used to characterize implosion performance. The Magnetic Recoil neutron Spectrometer (MRS), which is routinely used to measure yield, ion temperature (T_ion), and down-scatter ratio (dsr), has been adapted to allow measurements of dsr up to 5 × 10¹⁷, and yield and T_ion up to 2 × 10¹⁸ in the near term with new data processing techniques and conversion foil solutions. This paper presents a solution for extending MRS operation up to a yield of 2 × 10¹⁹ (60 MJ) by moving the spectrometer outside of the NIF shield wall. This will not only enhance the upper yield limit by 10× but also improve signal-to-background by 5×.

Experiments on the dynamics and scaling of spontaneous-magnetic-field saturation in laser-produced plasmas

In laser-produced high-energy-density plasmas, large-scale strong magnetic fields are spontaneously generated by the Biermann battery effects when temperature and density gradients are misaligned. Saturation of the magnetic field takes place when convection and dissipation balance field generation. While theoretical and numerical modeling provide useful insight into the saturation mechanisms, experimental demonstration remains elusive. In this letter, we report an experiment on the saturation dynamics and scaling of Biermann battery magnetic field in the regime where plasma convection dominates. With time-gated charged-particle radiography and time-resolved Thomson scattering, the field structure and evolution as well as corresponding plasma conditions are measured. In these conditions, the spatially resolved magnetic fields are reconstructed, leading to a picture of field saturation with a scaling of B∼1/L_{T} for a convectively dominated plasma, a regime where the temperature gradient scale (L_{T}) exceeds the ion skin depth.

Exploratory evaluation of baseline cognition as a predictor of perceived benefit in a study of behavioral therapy for urinary incontinence in Parkinson disease

AIMS

While behavior-based pelvic floor muscle exercise therapy is an effective treatment for overactive bladder in Parkinson's disease (PD) patients, cognitive function may be a predictor of rehabilitation outcomes.

METHODS

In a planned exploratory analysis, participants who had a Montreal Cognitive Assessment (MoCA) with a score ≥18 who were randomized in a clinical trial to behavioral treatment were classified by perceived improvement (Benefit vs. No Benefit) as reported on a validated Satisfaction and Benefit Questionnaire. General cognition (MoCA), motor procedural learning (Serial reaction time task), verbal memory (Buschke delayed recall), spatial memory (Nonverbal/Spatial selective reminding test), and working memory (Wisconsin card sorting task) were compared between the two groups using Wilcoxon rank-sum test.

RESULTS

Of the 26 participants randomized to behavioral treatment (70% male, mean age 71 ± 6.1 years), 22 participants (85%) reported Benefit and four reported No Benefit. General cognition, motor procedural learning, verbal memory, spatial memory, and working memory did not differ between these groups. While the difference between the time to complete the final practiced series and the random series of the Serial Reaction Time Task (SRTT) was statistically similar between the groups, the Benefit group performed the random sequence more quickly (567.0 ± 136.5 ms) compared to the No Benefit group (959.4 ± 443.0 ms; p = 0.03) and trended toward faster performance in the final practiced series.

CONCLUSIONS

Perceived benefit from behavioral treatment for overactive bladder was not associated with measures of baseline cognition other than faster completion of the SRTT. This is noteworthy because many behavior-based therapy studies exclude participants with mild cognitive impairment. Additional studies may evaluate if domain-specific cognitive function, particularly the assessment of implicit memory, could lead to individualized behavioral therapy recommendations.

Extension of charged-particle spectrometer capabilities for diagnosing implosions on OMEGA, Z, and the NIF

New designs and a new analysis technique have been developed for an existing compact charged-particle spectrometer on the NIF and OMEGA. The new analysis technique extends the capabilities of this diagnostic to measure arbitrarily shaped ion spectra down to 1 MeV with yields as low as 10⁶. Three different designs are provided optimized for the measurement of DD protons, T³He deuterons, and ³He³He protons. The designs are highly customizable, and a generalized framework is provided for optimizing the design for alternative applications. Additionally, the understanding of the detector's response and uncertainties is greatly expanded upon. A new calibration procedure is also developed to increase the precision of the measurements.

Characterizing x-ray transmission through filters used in high energy density physics diagnostics

We report on the design and implementation of a new system used to characterize the energy-dependent x-ray transmission curve, Θ(E), through filters used in high-energy density physics diagnostics. Using an Amptek X-123-CdTe x-ray spectrometer together with a partially depleted silicon surface barrier detector, both the energy spectrum and total emission of an x-ray source have been accurately measured. By coupling these detectors with a custom PROTO-XRD x-ray source with interchangeable cathodes, accurate characterizations of Θ(E) for filters of varying materials and thicknesses have been obtained. The validity of the technique has been confirmed by accurately reproducing areal densities for high-purity filters with known x-ray transmission properties. In this paper, the experimental setup is described and the results of absorption calibrations performed on a variety of different filters are presented.

Investigating changes in disease activity as a mediator of cardiovascular risk reduction with methotrexate use in rheumatoid arthritis

OBJECTIVE

Examine the association of methotrexate (MTX) use with cardiovascular disease (CVD) in rheumatoid arthritis (RA) using marginal structural models (MSM) and determine if CVD risk is mediated through modification of disease activity.

METHODS

We identified incident CVD events (coronary artery disease (CAD), stroke, heart failure (HF) hospitalisation, CVD death) within a multicentre, prospective cohort of US Veterans with RA. A 28-joint Disease Activity Score with C-reactive protein (DAS28-CRP) was collected at regular visits and medication exposures were determined by linking to pharmacy dispensing data. MSMs were used to estimate the treatment effect of MTX on risk of incident CVD, accounting for time-varying confounders between receiving MTX and CVD events. A mediation analysis was performed to estimate the indirect effects of methotrexate on CVD risk through modification of RA disease activity.

RESULTS

Among 2044 RA patients (90% male, mean age 63.9 years, baseline DAS28-CRP 3.6), there were 378 incident CVD events. Using MSM, MTX use was associated with a 24% reduced risk of composite CVD events (HR 0.76, 95% CI 0.58 to 0.99) including a 57% reduction in HF hospitalisations (HR 0.43, 95% CI 0.24 to 0.77). Individual associations with CAD, stroke and CVD death were not statistically significant. In mediation analyses, there was no evidence of indirect effects of MTX on CVD risk through disease activity modification (HR 1.03, 95% CI 0.80 to 1.32).

CONCLUSIONS

MTX use in RA was associated with a reduced risk of CVD events, particularly HF-related hospitalisations. These associations were not mediated through reductions in RA disease activity, suggesting alternative MTX-related mechanisms may modify CVD risk in this population.

Yield degradation due to laser drive asymmetry in D3He backlit proton radiography experiments at OMEGA

Mono-energetic proton radiography is a vital diagnostic for numerous high-energy-density-physics, inertial-confinement-fusion, and laboratory-astrophysics experiments at OMEGA. With a large number of campaigns executing hundreds of shots, general trends in D³He backlighter performance are statistically observed. Each experimental configuration uses a different number of beams and drive symmetry, causing the backlighter to perform differently. Here, we analyze the impact of these variables on the overall performance of the D³He backlighter for proton-radiography studies. This study finds that increasing laser drive asymmetry can degrade the performance of the D³He backlighter. The results of this study can be used to help experimental designs that use proton radiography.

Response of CR-39 nuclear track detectors to protons with non-normal incidence

This paper presents data from experiments with protons at non-normal incidence to CR-39 nuclear track detectors, analyzing the properties of detection efficiency, proton track diameter, track contrast, and track eccentricity. Understanding the CR-39 response to protons incident at an angle is important for designing charged particle detectors for inertial confinement fusion (ICF) applications. This study considers protons with incident energies less than 3 MeV. In this regime, an incident angle of 10° has no effect on CR-39 detection efficiency, and >85% detection efficiency is preserved up through 25° in the range of 1.0 MeV-2.1 MeV. For ICF applications, incident angles above 30° are deemed impractical for detector design due to significant drops in proton detection at all energies. We observe significant reductions in detection efficiency compared to theoretical predictions, particularly at low energies where proton tracks are etched away. The proton track diameter measured by the scan system is observed to decrease with higher incident angles. The track diameters are analyzed with two fitting models, and it is shown that the diameter-energy relation can be fit with the existing models at angles up to 30°. The optical contrast of the tracks tends to increase with the angle, meaning that the tracks are fainter, and a larger increase is observed for higher energies. Eccentricity, a measure of how elongated proton tracks are, increases with the incident angle and drops after the critical angle. The lowest energy tracks remain nearly circular even at higher angles.

Predictive ability, validity, and responsiveness of the multi-biomarker disease activity score in patients with rheumatoid arthritis initiating methotrexate

BACKGROUND/OBJECTIVE

We assessed the predictive value, validity, and responsiveness of the multi-biomarker disease activity (MBDA) score in rheumatoid arthritis (RA) patients initiating methotrexate.

METHODS

We examined data from a 16-week, open-label study of methotrexate in RA. Disease activity was assessed and the MBDA score was calculated using serum that was collected and banked from baseline and week 16. Multivariable logistic regression models assessed whether MBDA scores predicted treatment response. Pearson correlations assessed the convergent validity and external responsiveness of the MBDA score with other measures of RA disease activity. Internal responsiveness was assessed by calculating standardized response means (SRMs).

RESULTS

A total of 130 patients initiated the study, with follow-up MBDA scores available on 95 patients. Baseline MBDA scores did not predict ACR response or achieving low disease activity. Higher baseline DAS28-ESR scores were significantly associated with an ACR20 response (odds ratio 1.89 per unit, 95% CI 1.20-2.96) but not ACR50, ACR70, or low disease activity. The MBDA score moderate-to-weakly correlated with the DAS28-ESR and ESR at baseline and week 16, with weak-to-very weak correlations with patient global and function. Change in MBDA scores moderately correlated with changes in DAS28-ESR and ESR, while weakly correlating with changes in patient global and function. The DAS28-ESR (SRM 1.31) demonstrated greater responsiveness following methotrexate treatment than the MBDA score (SRM 0.71).

CONCLUSIONS

MBDA scores did not predict treatment response to methotrexate. The MBDA score weak-to-moderately correlated with baseline and post-treatment disease activity measures and was less responsive to methotrexate-related improvement than the DAS28-ESR.

Correlation of the Multi-Biomarker Disease Activity Score With Rheumatoid Arthritis Disease Activity Measures: A Systematic Review and Meta-Analysis

OBJECTIVE

There are conflicting reports on the validity of the multi-biomarker disease activity (MBDA) score for assessing rheumatoid arthritis (RA) disease activity. Our aim was to perform a systematic review of the MBDA and a meta-analysis of the correlation between the MBDA and other RA disease activity measures.

METHODS

A systematic review was performed by searching Medline, Embase, Scopus, Google Scholar, and the Cochrane Library from inception to March 7, 2017. Study details, MBDA performance, and study quality were assessed by independent reviewers. Correlations of the MBDA with composite RA disease activity measures were pooled using random-effects meta-analyses.

RESULTS

A total of 22 studies were identified in the systematic review, of which 8 (n = 3,242 assays) reported correlations of the MBDA with RA disease activity measures. Pooling results from these 8 studies in the meta-analysis, the MBDA demonstrated modest correlations with the Disease Activity Score in 28 joints using the C-reactive protein level (DAS28-CRP; r = 0.41, 95% confidence interval [95% CI] 0.36-0.46) and the Disease Activity Score using the erythrocyte sedimentation rate (DAS28-ESR; r = 0.48, 95% CI 0.38-0.58), with weaker correlations observed with the Simplified Disease Activity Index (SDAI; r = 0.35, 95% CI 0.26-0.43), Clinical Disease Activity Index (CDAI; r = 0.26, 95% CI 0.19-0.33), and Routine Assessment of Patient Index Data 3 (RAPID3; r = 0.23, 95% CI 0.19-0.27). Correlations between change in MBDA and change in disease activity measures ranged from r = 0.53 for the DAS28-ESR to r = 0.26 for the CDAI.

CONCLUSION

The MBDA demonstrates moderate convergent validity with the DAS28-CRP and the DAS28-ESR but weaker correlations with the SDAI, CDAI, and RAPID3. While it appears to complement existing RA disease activity measures, further assessment of the performance characteristics of the MBDA is warranted.

Postrigor citric acid enhancement can alter cooked color but not fresh color of dark-cutting beef

In 2 experiments, dark-cutting (DC) beef strip loins were used to test the effects of citric acid-enhancement pH on visual and instrumental color of fresh and cooked steaks. In Exp. 1 and 2, each DC (mean pH = 6.57 and 6.65, respectively) and normal-pH, low USDA Choice (CH; mean pH = 5.48 and 5.51, respectively) strip loin was cut into 2 equal-length sections, and DC sections were injected to 111% of raw section weight with pH 3.5 to 5.0 (Exp. 1) or pH 2.0 to 3.5 (Exp. 2) solutions made by mixing citric acid in either 0.05% orthophosphate (PO) solution or tap water (HO) base solutions (Exp. 1) and 0.5% PO or 0.5% tripolyphosphate solution base solutions (Exp. 2). After enhancement, sections were cut into steaks, which were assigned to either 5 d of simulated retail display or cooked to 71°C for cooked color measurement. Postenhancement pH of DC steaks enhanced with pH 3.5 to 5.0 solutions did not ( ≥ 0.180) differ from that of nonenhanced DC steaks (Exp. 1) but linearly decreased ( < 0.001) as solution pH decreased from 3.5 to 2.0 (Exp. 2). Even though fresh color scores were increased ( < 0.001) by citric acid enhancement over untreated DC steaks during the first 3 d of display, fresh steak color never ( < 0.001) approached that of nonenhanced CH steaks. When compared with nonenhanced DC steaks, enhancement with pH 3.5 to 5.0 solutions received lower cooked color scores, whereas enhancing DC sections with pH 2.5 solutions produced cooked color and degree-of-doneness scores similar ( ≥ 0.113) to those of nonenhanced CH steaks (Exp. 2). Results indicated that the pH of citric acid enhancement solutions, regardless of base solution, were insufficient to improve the fresh color of DC beef; however, enhancement with pH 2.5 citric acid solutions effectively eliminated the persistent red cooked color typically associated with DC beef comparable with that of normal-pH beef.

Uranium Isotopic Fractionation Induced by U(VI) Adsorption onto Common Aquifer Minerals

Uranium groundwater contamination due to U mining and processing affects numerous sites globally. Bioreduction of soluble, mobile U(VI) to U(IV)-bearing solids is potentially a very effective remediation strategy. Uranium isotopes (²³⁸U/²³⁵U) have been utilized to track the progress of microbial reduction, with laboratory and field studies finding a ∼1‰ isotopic fractionation, with the U(IV) product enriched in ²³⁸U. However, the isotopic fractionation produced by adsorption may complicate the use of ²³⁸U/²³⁵U to trace microbial reduction. A previous study found that adsorption of U(VI) onto Mn oxides produced a -0.2‰ fractionation with the adsorbed U(VI) depleted in ²³⁸U. In this study, adsorption to quartz, goethite, birnessite, illite, and aquifer sediments induced an average isotopic fractionation of -0.15‰ with the adsorbed U(VI) isotopically lighter than coexisting aqueous U(VI). In bicarbonate-bearing matrices, the fractionation depended little on the nature of the sorbent, with only birnessite producing an atypically large fractionation. In the case of solutions with ionic strengths much lower than those of typical groundwater, less isotopic fractionation was produced than U(VI) solutions with greater ionic strength. Studies using U isotope data to assess U(VI) reduction must consider adsorption as a lesser, but significant isotope fractionation process.

Compliance with and attitudes towards the management of medical emergencies in general dental practice

Patient safety and risk management are increasing priorities in dental practice today. Ensuring that members of the dental team are prepared and equipped to adequately manage the common medical emergencies that might occur is an expectation of the public and increasingly demanded by the inspecting and regulatory bodies in healthcare.

Aging is associated with increased HbA1c levels, independently of glucose levels and insulin resistance, and also with decreased HbA1c diagnostic specificity

AIM

To determine whether using HbA1c for screening and management could be confounded by age differences, whether age effects can be explained by unrecognized diabetes and prediabetes, insulin resistance or postprandial hyperglycaemia, and whether the effects of aging have an impact on diagnostic accuracy.

METHODS

We conducted a cross-sectional analysis in adults without known diabetes in the Screening for Impaired Glucose Tolerance (SIGT) study 2005-2008 (n=1573) and the National Health and Nutrition Examination Survey (NHANES) 2005-2006 (n=1184).

RESULTS

Both glucose intolerance and HbA(1c) levels increased with age. In univariate analyses including all subjects, HbA(1c) levels increased by 0.93 mmol/mol (0.085%) per 10 years of age in the SIGT study and by 1.03 mmol/mol (0.094%) per 10 years in the NHANES; in both datasets, the HbA(1c) increase was 0.87 mmol/mol (0.08%) per 10 years in subjects without diabetes, and 0.76 mmol/mol (0.07%) per 10 years in subjects with normal glucose tolerance, all P<0.001. In multivariate analyses of subjects with normal glucose tolerance, the relationship between age and HbA(1c) remained significant (P<0.001) after adjustment for covariates including race, BMI, waist circumference, sagittal abdominal diameter, triglyceride/HDL ratio, and fasting and 2-h plasma glucose and other glucose levels, as assessed by an oral glucose tolerance test. In both datasets, the HbA(1c) of an 80-year-old individual with normal glucose tolerance would be 3.82 mmol/mol (0.35%) greater than that of a 30-year-old with normal glucose tolerance, a difference that is clinically significant. Moreover, the specificity of HbA(1c) -based diagnostic criteria for prediabetes decreased substantially with increasing age (P<0.0001).

CONCLUSIONS

In two large datasets, using different methods to measure HbA(1c), the association of age with higher HbA(1c) levels: was consistent and similar; was both statistically and clinically significant; was unexplained by features of aging; and reduced diagnostic specificity. Age should be taken into consideration when using HbA(1c) for the diagnosis and management of diabetes and prediabetes.

Association of physical activity volume and hypercholesterolemia in US adults

BACKGROUND

Several studies illustrate the favorable association between physical activity (PA) and cholesterol levels. There is a paucity of data examining the PA patterns of individuals with and without hypercholesterolemia (HC).

AIM

To examine self-reported moderate and vigorous PA (MVPA) patterns using the most recent PA guidelines among US adults with and without HC.

DESIGN

Cross-sectional study utilizing a secondary data analysis approach.

METHODS

We used data from the 2009 Behavioral Risk Factor Surveillance System (BRFSS). PA categories were based on the 2008 Department of Health and Human Services (DHHS) guidelines.

RESULTS

The age-adjusted prevalence of self-reported HC in US adults was 34%. When stratified by gender, the age-adjusted prevalence of HC was found to be significantly higher in men (36.2%; 95% CI 35.6, 36.8) compared with women (31.8%; 95% CI 31.3, 32.3). The age-adjusted prevalence of meeting the DHHS PA recommendation was 59.1% among participants reporting HC and 68.3% among participants not reporting HC (P < 0.05). Following adjustment for demographics and health history, the odds ratio for meeting the DHHS PA recommendation among participants with HC compared with those without HC was 0.86 (95% CI 0.83, 0.89).

CONCLUSION

Although a large proportion of adults reporting HC report engaging in a volume of MVPA necessary to meet national guidelines, their odds of meeting these guidelines and their MVPA volume may be significantly lower than adults who did not report HC.

Self-rated sleep characteristics and bother from nocturia

PURPOSE

The aim of this study was to evaluate if men with varying degrees of bother from a similar number of nocturia episodes differ with respect to self-rated sleep characteristics and fatigue.

MATERIALS AND METHODS

As part of the baseline assessments during a nocturia treatment trial, 55 participants reported frequency and bother of nocturia using the AUA Symptom Inventory and completed 7-day sleep diaries prior to treatment. Participants who reported moderate nocturia (either two or three episodes nightly) were further grouped into categories of LOW (nocturia is no problem or a very small problem) or HIGH bother (nocturia is a big problem). Information from the participant completed sleep diaries was abstracted, including information on daytime napping, total sleep time, mean time needed to return to sleep, nighttime ratings of fatigue, and daytime ratings of fatigue.

RESULTS

Of the 55 individuals who completed the pilot study, 24 study participants reported two or three episodes of nocturia and had either HIGH (n = 11) or LOW (n = 13) bother. Participants categorised with HIGH bother were significantly more likely than those with LOW bother to report difficulty initiating sleep (47.7 ± 34.4 vs. 23.5 ± 13.6 min, p = 0.05), difficulty returning to sleep after an awakening (28.9 ± 16.1 vs. 15.4 ± 9.6 min, p = 0.03) and greater morning fatigue (3.3 ± 0.7 vs. 2.5 ± 1.0, p = 0.04 on a 7-point scale).

CONCLUSIONS

Since bother related to nocturia is linked to sleep quality, interventions targeting fatigue and sleep maintenance may provide useful targets in the management of nocturia in men.

The association of nocturia with incident falls in an elderly community-dwelling cohort

OBJECTIVE

The aim of this study was to examine the association of nocturia with incident falls in a population-based sample of community-dwelling elderly persons.

METHODS

The University of Alabama at Birmingham Study of Aging is a prospective cohort study of 1000 community-dwelling older adults in the USA designed to examine factors associated with impaired mobility. Subjects were recruited from a stratified, random sample of Medicare beneficiaries to include equal numbers of black women, black men, white women and white men. Nocturia was assessed at baseline and falls were assessed at baseline and every 6 months for a total of 36 months of follow-up.

RESULTS

A total of 692 individuals (mean age 74.5 +/- 6.2, 48% female, 52% black) did not fall in the 12 months prior to baseline. Of these 692, 214 (30.9%) reported falling at least once during the subsequent 3 years. In unadjusted analysis, three or more nightly episodes of nocturia were associated with an incident fall [RR = 1.27, 95% CI (1.01-1.60)]. After multivariable logistic regression, three or more episodes of nocturia were associated with an increased risk of falling [RR = 1.28, (1.02-1.59)].

DISCUSSION

In a racially diverse, community-based sample of older men and women who had not fallen in the previous year, nocturia three or more times a night was associated in multivariable analysis with a 28% increased risk of an incident fall within 3 years. While this study has several advantages over previous reports (longitudinal follow-up, performance-based measures of function, population-based sampling), causality cannot be ascertained. Further research is needed to ascertain the impact of treatments to reduce nocturia as part of a multi-component programme to reduce fall risk.

Animal-type melanoma: a clinical and histopathological study of 22 cases from a single institution

Background Animal-type melanoma is a rare distinct melanoma subtype, characterized by proliferation of heavily pigmented epithelioid and spindled melanocytes that resembles the heavily pigmented melanomas seen in grey horses. While animal-type melanoma is generally considered to be more indolent than conventional melanoma, only a limited number of cases have been reported and, as such, the clinical characteristics of animal-type melanoma are incompletely understood. Objectives To characterize the clinical and histopathological features of animal-type melanoma, and determine any features that may predict outcome. Patients/Methods Data was extracted from a prospectively collected melanoma database (1994-2008), and a retrospective pathology database (1991-2008) for all patients with a diagnosis of both equivocal (8) and unequivocal (14) malignant animal-type melanoma. We reviewed the clinical and histopathological features, including the sentinel lymph node biopsy (SLNB) status. Results A total of 22 patients were identified, with a median age of 35 years. The median Breslow depth was 2.22 mm. A SLNB was performed in 17 patients, eight (47%) were positive. Younger age was associated with: (i) animal-type melanoma with features equivocal for malignancy (median age of 7 vs. 48 years, P = 0.01), and (ii) a negative SLNB (median age 12 vs. 53 years, P = 0.03). Four patients with unequivocal animal-type melanoma developed recurrent metastatic disease, with one patient death. No patient with an equivocal animal-type melanoma or negative SLNB developed recurrent disease; however, this did not reach statistical significance (P = 0.13 and P = 0.09, respectively). Conclusions Animal-type melanoma has a propensity for regional lymphatic metastasis and is rarely capable of disseminated metastatic disease and death. Animal-type melanoma appears to exhibit a spectrum of biological behaviour, with young patient age associated with more indolent disease.

Polarized angular dependent spectroscopy of epithelial cells and epithelial cell nuclei to determine the size scale of scattering structures

An understanding of the relationship between tissue structures and light scattering from tissue will help facilitate the development and acceptance of noninvasive optical diagnostics including elastic scattering spectroscopy, diffuse reflectance, and optical coherence tomography. For example, a quantitative model of the structures that scatter light in epithelial cells would allow determination of what structures control the characteristics of in vivo light transport measurements and subsequently could provide a detailed relationship between cellular structures and optical measurements. We have determined the size distribution of refractive index structure variations in epithelial cells as well as in nuclei isolated from epithelial cells from measurements of the angular dependence of polarized light scattering. The quantitative size distributions we obtained for both whole cells and isolated nuclei include particles with effective radii of 2 microm to 10 nm or less and contain orders of magnitude more small particles than large particles. These results demonstrate that not only are biological cells very heterogeneous, but so are the nuclei within them. Light scattering is likely sensitive to structures smaller than those commonly investigated by standard pathology methods.

Angular dependent light scattering from multicellular spheroids

We demonstrate that the effects of cell-cell contact and of changes in cell shape have only a minor effect on the angular distribution of light scattering from mammalian fibroblast cells. This result is important for the development of light scattering as a noninvasive tool for tissue diagnostics such as cancer detection. Changes in cell organization that are not accompanied by changes in internal cellular structure may not be measurable. On the other hand, changes in internal cellular structure should be measurable without interference from changes in overall cellular organization. The second major result of this work is that there are small but significant differences between light scattering of tumorigenic and nontumorigenic cells grown in a three-dimensional culture system. The cause of the differences in light scattering are likely due to the nontumorigenic cells arresting in the G1 phase of the cell cycle, while the tumorigenic cells continue to proliferate.

Age-based refinement of referral criteria for photoscreening

OBJECTIVE

To evaluate examination results from preschool children referred from photoscreening, and to adjust referral criteria for suspected astigmatism.

DESIGN

Cross-sectional study and noncomparative case series.

PARTICIPANTS

Thirty-one thousand fifty-three preschool children.

METHODS

Analysis of (1) referral rate and unreadable photograph rate for all children screened, (2) examination results and treatment plan for all children referred for suspected astigmatism, and (3) examination results and treatment for all referred children aged less than 1 year.

MAIN OUTCOME MEASURES

Referral rate, unreadable photograph rate, predictive value positive, treatment plan.

RESULTS

The referral rate dropped from 7.8% for children 6 to 11 months to 5.3% for all other ages. The unreadable photograph rate declined exponentially from 12.1% for children aged 6 to 11 months to 1.1% for children aged 4 years. The predictive value positive of a photoscreen referral for all children in the 6- to 11-month age group was 30%, and only 12 of the 94 referred children were treated. The predictive value positive for children less than 1 year of age referred with suspected astigmatism was even lower (25%), and only one child in this age group was treated. The predictive value positive increased with age, and a higher percentage of older children were treated. For children at least 3 years old referred for suspected astigmatism, the predictive value positive was 67% when the examination was performed by a pediatric ophthalmologist. Strabismus, anisometropia, and high hypermetropia were diagnosed in such patients age 2 and older but never in younger children.

CONCLUSIONS

Children less than 1 year of age have a much lower pass rate from photoscreening than do older children because of a higher referral rate and higher unreadable rate in this age group. When these children are examined, significant pathosis is usually absent, and intervention is rarely initiated. Most children age 2 and older who are referred for suspected astigmatism have a high likelihood of significant pathosis. It is probably unnecessary to examine children less than age 2 when their photoscreening suggests only astigmatism; conversely, referrals should still be provided for these children when their screening suggests other potentially amblyogenic factors.

Characterizing Mammalian cells and cell phantoms by polarized backscattering fiber-optic measurements

Fiber-optic, polarized elastic-scattering spectroscopy techniques are implemented and demonstrated as a method for determining both scatterer size and concentration in highly scattering media. Measurements of polystyrene spheres are presented to validate the technique. Measurements of biological cells provide an estimate of the average effective scatterer radius of 0.5-1.0 mum. This average effective scatterer size is significantly smaller than the nucleus. In addition, to facilitate use of polarization techniques on biological cells, polarized angular dependent scattering from cell suspensions was measured. The light scattering from cells has properties similar to those of small spheres.

Prevalence of factor V Leiden and activated protein C resistance in central retinal vein occlusion

PURPOSE

Factor V Leiden is a common inherited mutation that is a significant risk factor for deep vein thrombosis. It results in resistance to activated protein C (APC). The association between factor V Leiden and central retinal vein occlusion (CRVO) remains controversial. This study was designed to determine the prevalence of APC resistance and the factor V Leiden mutation in patients with CRVO in a controlled study.

METHODS

The study was designed as a case control study conducted in a tertiary care retina practice. The prevalence of APC resistance and factor V Leiden was determined by genetic testing of blood samples obtained from patients with CRVO and clinic control patients.

RESULTS

Factor V Leiden was identified in 2.3% of patients with CRVO and 3.5% of clinic control patients. There was no significant association between the presence of factor V Leiden and CRVO (odds ratio, 1.13; 95% confidence interval, 0.65-1.98; P = 0.66).

CONCLUSION

Factor V Leiden does not appear to be associated with CRVO. Routine screening of patients with CRVO does not appear to be warranted.

Cytomegalovirus infection increases development of atherosclerosis in Apolipoprotein-E knockout mice

Cytomegalovirus (CMV) infection has been associated with coronary artery disease, but it is unknown whether the virus can causally contribute to atherogenesis. To determine whether the virus has this capacity, we infected an atherosclerotic-prone mouse strain (C57BL/6J apoE-/-) with murine CMV. At 14 days of age, 30 mice received CMV (30000 pfu) ip and 30 received virus free media. At 13 and 16 weeks atherosclerotic lesion size was measured from aortic sinus cross-sections. Infection did not alter plasma levels of cholesterol, triglycerides, and high density lipoprotein (HDL); however, 4 weeks after infection IFNgamma levels were elevated (infection vs control: 156+/-49 vs 50+/-22 pg/ml, P=0.04). No differences in lesion size were present at 13 weeks post infection. However, by 16 weeks mean aortic sinus lesion area (mm(2)x10(3)+/-SEM; N=75) in the CMV-infected mice was significantly greater than in uninfected mice (74+/-6 vs 57+/-6; P=0.04). CMV caused the greatest increase (34%) in lesion size in females (103+/-9 vs 77+/-10; P=0.05; N=35). These results provide additional evidence implicating CMV as a causal agent of atherosclerosis, at least in an animal model.

Treatment of head and neck melanoma, lentigo maligna subtype: a practical surgical technique

Melanoma with the lentigo maligna histological pattern often provides a significant and difficult challenge to the head and neck surgeon. The lentigo maligna subtype is the most common type of melanoma on the head and neck. This potentially lethal form of cancer is associated with greater nonvisual lesional extension that is often not clinically apparent. Failure to excise the entire lesion results in a higher risk of local recurrence and a poorer prognosis. The staged excision technique described herein results in histological interpretation of 100% of the peripheral margins using formalin-fixed vertical sections. Definitive local excision and soft tissue reconstruction are performed in a subsequent stage, with an assurance that 100% of the peripheral margins have been evaluated and interpreted as free of disease.

Urinary incontinence treatment preferences in long-term care

OBJECTIVE

To elicit preferences for different urinary incontinence (UI) treatments in long-term care (LTC) from groups likely to serve as proxy decision makers for LTC residents.

DESIGN

A descriptive, comparative study of preference for UI treatments of frail older adults, family members of nursing home (NH) residents, and LTC nursing staff. Surveys were mailed to families and self-administered by staff. Older adults were interviewed.

SETTING

Four LTC facilities and two residential-care facilities in Los Angeles.

PARTICIPANTS

Four hundred and three family members of incontinent NH residents were mailed surveys. Sixty-six nursing staff caring for these incontinent residents and 79 older adult residents of care facilities (nine cognitively intact NH respondents and 70 residential care residents) answered surveys.

MEASUREMENTS

Preference rankings between seven paired combinations of five different UI treatments were measured on an 11-point visual analog scale, with the verbal anchors "definitely prefer" this treatment, "probably prefer" this treatment, and "uncertain." Respondents gave open-ended comments as well.

RESULTS

Forty-two percent of family members (171/ 403) returned the mailed survey. Of all respondents, 85% "definitely" or "probably" preferred diapers, and 77% "definitely" or "probably" preferred prompted voiding (PV) to indwelling catheterization. Respondent groups occasionally differed significantly in their preferences. In choosing between treatment pairs using a visual analogue scale, nurses preferred PV to diapers significantly more than did older adults or families (both of whom preferred diapers) (F (2,295) = 13.11, P < .0001). Older adults, compared with family and nurse respondents, showed a significantly stronger preference for medications over diapers (F (2,296) = 41.54, P < .0001). In open-ended responses, older adults stated that they would choose a UI treatment based in part upon criteria of feeling dry, being natural, not causing embarrassment, being easy, and not resulting in dependence. Nurses said that they would base their choice of UI treatment upon increasing self-esteem and avoiding infection.

CONCLUSIONS

Although there was wide variation within and between groups about preferred UI treatment, most respondents preferred noninvasive strategies (diapers and PV) to invasive strategies (indwelling catheters and electrical stimulation). Older adults preferred to a greater degree medications and electrical stimulation, therapies directed at the underlying cause of UI. Despite data documenting that diapering is a less time intensive way to manage UI and that toileting programs are difficult to maintain in LTC, nurses viewed PV as "natural" and strongly preferred it to diapering. Several family members and older adults viewed PV as "embarrassing" and "fostering dependence." These data highlight the need to elicit preferences for UI treatment among LTC residents and their families.

The forehead flap for nasal reconstruction

CONTEXT

Reconstruction of extensive nasal defects often represents a significant challenge owing to several unique qualities of the nose, such as complex topography, mobile free margins, and multiple nasal subunits. Furthermore, loss of internal nasal lining and/or structural skeletal support may be present following removal of extensive skin cancers.

OBJECTIVE

To describe our experience with the use of forehead flap reconstruction for extensive nasal defects.

DESIGN

Retrospective case series.

SETTING

Academic health care hospital system.

PATIENTS/INTERVENTION

One hundred forty-seven patients with extensive nasal defects repaired with a forehead flap.

MAIN OUTCOME MEASURES

The functional and aesthetic results were assessed. The characteristics of defects repaired with the forehead flap and the need for lining and/or cartilage were examined.

RESULTS

The forehead flap was used to repair 147 nasal defects after Mohs excision of nonmelanoma skin cancer. Full-thickness skin was lost in all cases, structural skeletal support in 68 cases (46%), and internal mucosal lining in 45 cases (31%). Our experience and surgical technique using the forehead flap are described.

CONCLUSIONS

The forehead flap represents one of the best methods for repair of extensive nasal defects. Near-normal functional and cosmetic results can be achieved.