Lateral lumbar interbody fusion at L4-L5 has a low rate of complications in appropriately selected patients when using a standardized surgical technique

Aims

The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.

Methods

This was a multicentre retrospective study involving consecutively enrolled patients who underwent L4-L5 LLIF by seven surgeons at seven institutions in three countries over a five-year period. The demographic details of the patients and the details of the surgery, reoperations and complications, including femoral and non-femoral neuropraxia, thigh pain, weakness of hip flexion, and abdominal complications, were analyzed. Neurological and psoas-related complications attributed to LLIF or posterior instrumentation and persistent symptoms were recorded at one year postoperatively.

Results

A total of 517 patients were included in the study. Their mean age was 65.0 years (SD 10.3) and their mean BMI was 29.2 kg/m2 (SD 5.5). A mean of 1.2 levels (SD 0.6) were fused with LLIF, and a mean of 1.6 (SD 0.9) posterior levels were fused. Femoral neuropraxia occurred in six patients (1.2%), of which four (0.8%) were LLIF-related and two (0.4%) had persistent symptoms one year postoperatively. Non-femoral neuropraxia occurred in nine patients (1.8%), one (0.2%) was LLIF-related and five (1.0%) were persistent at one year. All LLIF-related neuropraxias resolved by one year. A total of 32 patients (6.2%) had thigh pain, 31 (6.0%) were LLIF-related and three (0.6%) were persistent at one year. Weakness of hip flexion occurred in 14 patients (2.7%), of which eight (1.6%) were LLIF-related and three (0.6%) were persistent at one year. No patients had bowel injury, three (0.6%) had an intraoperative vascular injury (not LLIF-related), and five (1.0%) had ileus. Reoperations occurred in five patients (1.0%) within 30 days, 37 (7.2%) within 90 days, and 41 (7.9%) within one year postoperatively.

Conclusion

LLIF involving the L4-L5 disc level has a low rate of persistent neurological, psoas-related, and abdominal complications in patients with the appropriate indications and using a standardized surgical technique.

Maleic acid is a biomarker for maleylacetoacetate isomerase deficiency; implications for newborn screening of tyrosinemia type 1

Dried blood spot succinylacetone (SA) is often used as a biomarker for newborn screening (NBS) for tyrosinemia type 1 (TT1). However, false-positive SA results are often observed. Elevated SA may also be due to maleylacetoacetate isomerase deficiency (MAAI-D), which appears to be clinically insignificant. This study investigated whether urine organic acid (uOA) and quantitative urine maleic acid (Q-uMA) analyses can distinguish between TT1 and MAAI-D. We reevaluated/measured uOA (GC-MS) and/or Q-uMA (LC-MS/MS) in available urine samples of nine referred newborns (2 TT1, 7 false-positive), eight genetically confirmed MAAI-D children, and 66 controls. Maleic acid was elevated in uOA of 5/7 false-positive newborns and in the three available samples of confirmed MAAI-D children, but not in TT1 patients. Q-uMA ranged from not detectable to 1.16 mmol/mol creatinine in controls (n = 66) and from 0.95 to 192.06 mmol/mol creatinine in false-positive newborns and MAAI-D children (n = 10). MAAI-D was genetically confirmed in 4/7 false-positive newborns, all with elevated Q-uMA, and rejected in the two newborns with normal Q-uMA. No sample was available for genetic analysis of the last false-positive infant with elevated Q-uMA. Our study shows that MAAI-D is a recognizable cause of false-positive TT1 NBS results. Elevated urine maleic acid excretion seems highly effective in discriminating MAAI-D from TT1.

The impact of knowledge, self-efficacy, and stigma on STI testing intention among college students

Objective: Young people represent over half of the new cases of sexually transmitted infections (STIs) each year in the United States. This study examined how STI knowledge, self-efficacy, and stigma impact STI testing intention among sexually active college students using path model analysis. Participants: Participants included 76 college students (74.1% undergraduate, M_age = 23.05). Method: Data were collected via online survey. Path analysis was conducted using SPSS AMOS, and MacKinnon's ab product approach in RMediation was used to test mediating effects. Results: The hypothesized path model fit the data well and the relationships between self-efficacy and knowledge, stigma, and STI testing intention were significant. Mediation analysis revealed significant indirect paths for knowledge and stigma on STI testing intention through self-efficacy. Conclusion: Findings suggest that college health providers may be able to increase the frequency of STI testing behavior by promoting strategies to increase students' self-efficacy.

Demonstrating an approach for evaluating synthetic geospatial and temporal epidemiologic data utility: results from analyzing >1.8 million SARS-CoV-2 tests in the United States National COVID Cohort Collaborative (N3C)

OBJECTIVE

This study sought to evaluate whether synthetic data derived from a national coronavirus disease 2019 (COVID-19) dataset could be used for geospatial and temporal epidemic analyses.

MATERIALS AND METHODS

Using an original dataset (n = 1 854 968 severe acute respiratory syndrome coronavirus 2 tests) and its synthetic derivative, we compared key indicators of COVID-19 community spread through analysis of aggregate and zip code-level epidemic curves, patient characteristics and outcomes, distribution of tests by zip code, and indicator counts stratified by month and zip code. Similarity between the data was statistically and qualitatively evaluated.

RESULTS

In general, synthetic data closely matched original data for epidemic curves, patient characteristics, and outcomes. Synthetic data suppressed labels of zip codes with few total tests (mean = 2.9 ± 2.4; max = 16 tests; 66% reduction of unique zip codes). Epidemic curves and monthly indicator counts were similar between synthetic and original data in a random sample of the most tested (top 1%; n = 171) and for all unsuppressed zip codes (n = 5819), respectively. In small sample sizes, synthetic data utility was notably decreased.

DISCUSSION

Analyses on the population-level and of densely tested zip codes (which contained most of the data) were similar between original and synthetically derived datasets. Analyses of sparsely tested populations were less similar and had more data suppression.

CONCLUSION

In general, synthetic data were successfully used to analyze geospatial and temporal trends. Analyses using small sample sizes or populations were limited, in part due to purposeful data label suppression-an attribute disclosure countermeasure. Users should consider data fitness for use in these cases.

Unraveling COVID-19: A Large-Scale Characterization of 4.5 Million COVID-19 Cases Using CHARYBDIS

Purpose

Routinely collected real world data (RWD) have great utility in aiding the novel coronavirus disease (COVID-19) pandemic response. Here we present the international Observational Health Data Sciences and Informatics (OHDSI) Characterizing Health Associated Risks and Your Baseline Disease In SARS-COV-2 (CHARYBDIS) framework for standardisation and analysis of COVID-19 RWD.

Patients and Methods

We conducted a descriptive retrospective database study using a federated network of data partners in the United States, Europe (the Netherlands, Spain, the UK, Germany, France and Italy) and Asia (South Korea and China). The study protocol and analytical package were released on 11th June 2020 and are iteratively updated via GitHub. We identified three non-mutually exclusive cohorts of 4,537,153 individuals with a clinical COVID-19 diagnosis or positive test, 886,193 hospitalized with COVID-19, and 113,627 hospitalized with COVID-19 requiring intensive services.

Results

We aggregated over 22,000 unique characteristics describing patients with COVID-19. All comorbidities, symptoms, medications, and outcomes are described by cohort in aggregate counts and are readily available online. Globally, we observed similarities in the USA and Europe: more women diagnosed than men but more men hospitalized than women, most diagnosed cases between 25 and 60 years of age versus most hospitalized cases between 60 and 80 years of age. South Korea differed with more women than men hospitalized. Common comorbidities included type 2 diabetes, hypertension, chronic kidney disease and heart disease. Common presenting symptoms were dyspnea, cough and fever. Symptom data availability was more common in hospitalized cohorts than diagnosed.

Conclusion

We constructed a global, multi-centre view to describe trends in COVID-19 progression, management and evolution over time. By characterising baseline variability in patients and geography, our work provides critical context that may otherwise be misconstrued as data quality issues. This is important as we perform studies on adverse events of special interest in COVID-19 vaccine surveillance.

Adaptive Cardiac Resynchronization Therapy Effect on Electrical Dyssynchrony (aCRT-ELSYNC): A randomized controlled trial

BACKGROUND

Adaptive cardiac resynchronization therapy (aCRT) is known to have clinical benefits over conventional CRT, but the mechanisms are unclear.

OBJECTIVE

Compare effects of aCRT and conventional CRT on electrical dyssynchrony.

METHODS

A prospective, double-blind, 1:1 parallel-group assignment randomized controlled trial in patients receiving CRT for routine clinical indications. Participants underwent cardiac computed tomography and 128-electrode body surface mapping. The primary outcome was change in electrical dyssynchrony measured on the epicardial surface using noninvasive electrocardiographic imaging before and 6 months post-CRT. Ventricular electrical uncoupling (VEU) was calculated as the difference between the mean left ventricular (LV) and right ventricular (RV) activation times. An electrical dyssynchrony index (EDI) was computed as the standard deviation of local epicardial activation times.

RESULTS

We randomized 27 participants (aged 64 ± 12 years; 34% female; 53% ischemic cardiomyopathy; LV ejection fraction 28% ± 8%; QRS duration 155 ± 21 ms; typical left bundle branch block [LBBB] in 13%) to conventional CRT (n = 15) vs aCRT (n = 12). In atypical LBBB (n = 11; 41%) with S waves in V5-V6, conduction block occurred in the anterior RV, as opposed to the interventricular groove in strict LBBB. As compared to baseline, VEU reduced post-CRT in the aCRT (median reduction 18.9 [interquartile range 4.3-29.2 ms; P = .034]), but not in the conventional CRT (21.4 [-30.0 to 49.9 ms; P = .525]) group. There were no differences in the degree of change in VEU and EDI indices between treatment groups.

CONCLUSION

The effect of aCRT and conventional CRT on electrical dyssynchrony is largely similar, but only aCRT harmoniously reduced interventricular dyssynchrony by reducing RV uncoupling.

Demonstrating an approach for evaluating synthetic geospatial and temporal epidemiologic data utility: Results from analyzing >1.8 million SARS-CoV-2 tests in the United States National COVID Cohort Collaborative (N3C)

OBJECTIVE

To evaluate whether synthetic data derived from a national COVID-19 data set could be used for geospatial and temporal epidemic analyses.

MATERIALS AND METHODS

Using an original data set (n=1,854,968 SARS-CoV-2 tests) and its synthetic derivative, we compared key indicators of COVID-19 community spread through analysis of aggregate and zip-code level epidemic curves, patient characteristics and outcomes, distribution of tests by zip code, and indicator counts stratified by month and zip code. Similarity between the data was statistically and qualitatively evaluated.

RESULTS

In general, synthetic data closely matched original data for epidemic curves, patient characteristics, and outcomes. Synthetic data suppressed labels of zip codes with few total tests (mean=2.9±2.4; max=16 tests; 66% reduction of unique zip codes). Epidemic curves and monthly indicator counts were similar between synthetic and original data in a random sample of the most tested (top 1%; n=171) and for all unsuppressed zip codes (n=5,819), respectively. In small sample sizes, synthetic data utility was notably decreased.

DISCUSSION

Analyses on the population-level and of densely-tested zip codes (which contained most of the data) were similar between original and synthetically-derived data sets. Analyses of sparsely-tested populations were less similar and had more data suppression.

CONCLUSION

In general, synthetic data were successfully used to analyze geospatial and temporal trends. Analyses using small sample sizes or populations were limited, in part due to purposeful data label suppression -an attribute disclosure countermeasure. Users should consider data fitness for use in these cases.

Neuropsychological test validation of speech markers of cognitive impairment in the Framingham Cognitive Aging Cohort

AIM

Although clinicians primarily diagnose dementia based on a combination of metrics such as medical history and formal neuropsychological tests, recent work using linguistic analysis of narrative speech to identify dementia has shown promising results. We aim to build upon research by Thomas JA & Burkardt HA et al. (J Alzheimers Dis. 2020;76:905-22) and Alhanai et al. (arXiv:1710.07551v1. 2020) on the Framingham Heart Study (FHS) Cognitive Aging Cohort by 1) demonstrating the predictive capability of linguistic analysis in differentiating cognitively normal from cognitively impaired participants and 2) comparing the performance of the original linguistic features with the performance of expanded features.

METHODS

Data were derived from a subset of the FHS Cognitive Aging Cohort. We analyzed a sub-selection of 98 participants, which provided 127 unique audio files and clinical observations (n = 127, female = 47%, cognitively impaired = 43%). We built on previous work which extracted original linguistic features from transcribed audio files by extracting expanded features. We used both feature sets to train logistic regression classifiers to distinguish cognitively normal from cognitively impaired participants and compared the predictive power of the original and expanded linguistic feature sets, and participants' Mini-Mental State Examination (MMSE) scores.

RESULTS

Based on the area under the receiver-operator characteristic curve (AUC) of the models, both the original (AUC = 0.882) and expanded (AUC = 0.883) feature sets outperformed MMSE (AUC = 0.870) in classifying cognitively impaired and cognitively normal participants. Although the original and expanded feature sets had similar AUC, the expanded feature set showed better positive and negative predictive value [expanded: positive predictive value (PPV) = 0.738, negative predictive value (NPV) = 0.889; original: PPV = 0.701, NPV = 0.869].

CONCLUSIONS

Linguistic analysis has been shown to be a potentially powerful tool for clinical use in classifying cognitive impairment. This study expands the work of several others, but further studies into the plausibility of speech analysis in clinical use are vital to ensure the validity of speech analysis for clinical classification of cognitive impairment.

Assessing the Utility of Language and Voice Biomarkers to Predict Cognitive Impairment in the Framingham Heart Study Cognitive Aging Cohort Data

BACKGROUND

There is a need for fast, accessible, low-cost, and accurate diagnostic methods for early detection of cognitive decline. Dementia diagnoses are usually made years after symptom onset, missing a window of opportunity for early intervention.

OBJECTIVE

To evaluate the use of recorded voice features as proxies for cognitive function by using neuropsychological test measures and existing dementia diagnoses.

METHODS

This study analyzed 170 audio recordings, transcripts, and paired neuropsychological test results from 135 participants selected from the Framingham Heart Study (FHS), which includes 97 recordings of cognitively normal participants and 73 recordings of cognitively impaired participants. Acoustic and linguistic features of the voice samples were correlated with cognitive performance measures to verify their association.

RESULTS

Language and voice features, when combined with demographic variables, performed with an AUC of 0.942 (95% CI 0.929-0.983) in predicting cognitive status. Features with good predictive power included the acoustic features mean spectral slope in the 500-1500 Hz band, variation in the F2 bandwidth, and variation in the Mel-Frequency Cepstral Coefficient (MFCC) 1; the demographic features employment, education, and age; and the text features of number of words, number of compound words, number of unique nouns, and number of proper names.

CONCLUSION

Several linguistic and acoustic biomarkers show correlations and predictive power with regard to neuropsychological testing results and cognitive impairment diagnoses, including dementia. This initial study paves the way for a follow-up comprehensive study incorporating the entire FHS cohort.

Baseline phenotype and 30-day outcomes of people tested for COVID-19: an international network cohort including >3.32 million people tested with real-time PCR and >219,000 tested positive for SARS-CoV-2 in South Korea, Spain and the United States

Early identification of symptoms and comorbidities most predictive of COVID-19 is critical to identify infection, guide policies to effectively contain the pandemic, and improve health systems' response. Here, we characterised socio-demographics and comorbidity in 3,316,107persons tested and 219,072 persons tested positive for SARS-CoV-2 since January 2020, and their key health outcomes in the month following the first positive test. Routine care data from primary care electronic health records (EHR) from Spain, hospital EHR from the United States (US), and claims data from South Korea and the US were used. The majority of study participants were women aged 18-65 years old. Positive/tested ratio varied greatly geographically (2.2:100 to 31.2:100) and over time (from 50:100 in February-April to 6.8:100 in May-June). Fever, cough and dyspnoea were the most common symptoms at presentation. Between 4%-38% required admission and 1-10.5% died within a month from their first positive test. Observed disparity in testing practices led to variable baseline characteristics and outcomes, both nationally (US) and internationally. Our findings highlight the importance of large scale characterization of COVID-19 international cohorts to inform planning and resource allocation including testing as countries face a second wave.

Mechanisms of Arrhythmogenicity in Hypertrophic Cardiomyopathy: Insight From Non-invasive Electrocardiographic Imaging

Background

Mechanisms of arrhythmogenicity in hypertrophic cardiomyopathy (HCM) are not well understood.

Objective

To characterize an electrophysiological substrate of HCM in comparison to ischemic cardiomyopathy (ICM), or healthy individuals.

Methods

We conducted a prospective case-control study. The study enrolled HCM patients at high risk for ventricular tachyarrhythmia (VT) [n = 10; age 61 ± 9 years; left ventricular ejection fraction (LVEF) 60 ± 9%], and three comparison groups: healthy individuals (n = 10; age 28 ± 6 years; LVEF > 70%), ICM patients with LV hypertrophy (LVH) and known VT (n = 10; age 64 ± 9 years; LVEF 31 ± 15%), and ICM patients with LVH and no known VT (n = 10; age 70 ± 7 years; LVEF 46 ± 16%). All participants underwent 12-lead ECG, cardiac CT or MRI, and 128-electrode body surface mapping (BioSemi ActiveTwo, Netherlands). Non-invasive voltage and activation maps were reconstructed using the open-source SCIRun (University of Utah) inverse problem-solving environment.

Results

In the epicardial basal anterior segment, HCM patients had the greatest ventricular activation dispersion [16.4 ± 5.5 vs. 13.1 ± 2.7 (ICM with VT) vs. 13.8 ± 4.3 (ICM no VT) vs. 8.1 ± 2.4 ms (Healthy); P = 0.0007], the largest unipolar voltage [1094 ± 211 vs. 934 ± 189 (ICM with VT) vs. 898 ± 358 (ICM no VT) vs. 842 ± 90 μV (Healthy); P = 0.023], and the greatest voltage dispersion [median (interquartile range) 215 (161–281) vs. 189 (143–208) (ICM with VT) vs. 158 (109–236) (ICM no VT) vs. 110 (106–168) μV (Healthy); P = 0.041]. Differences were also observed in other endo-and epicardial basal and apical segments.

Conclusion

HCM is characterized by a greater activation dispersion in basal segments, a larger voltage, and a larger voltage dispersion through LV.

Clinical Trial Registration

www.clinicaltrials.gov Unique identifier: NCT02806479.

Dynamic predictive accuracy of electrocardiographic biomarkers of sudden cardiac death within a survival framework: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

The risk of sudden cardiac death (SCD) is known to be dynamic. However, the accuracy of a dynamic SCD prediction is unknown. We aimed to measure the dynamic predictive accuracy of ECG biomarkers of SCD and competing non-sudden cardiac death (non-SCD).

METHODS

Atherosclerosis Risk In Community study participants with analyzable ECGs in sinus rhythm were included (n = 15,716; 55% female, 73% white, age 54.2 ± 5.8 y). ECGs of 5 follow-up visits were analyzed. Global electrical heterogeneity and traditional ECG metrics (heart rate, QRS, QTc) were measured. Adjudicated SCD was the primary outcome; non-SCD was the competing outcome. Time-dependent area under the receiver operating characteristic curve (ROC(t) AUC) analysis was performed to assess the prediction accuracy of a continuous biomarker in a period of 3,6,9 months, and 1,2,3,5,10, and 15 years using a survival analysis framework. Reclassification improvement as compared to clinical risk factors (age, sex, race, diabetes, hypertension, coronary heart disease, stroke) was measured.

RESULTS

Over a median 24.4 y follow-up, there were 577 SCDs (incidence 1.76 (95%CI 1.63-1.91)/1000 person-years), and 829 non-SCDs [2.55 (95%CI 2.37-2.71)]. No ECG biomarkers predicted SCD within 3 months after ECG recording. Within 6 months, spatial ventricular gradient (SVG) elevation predicted SCD (AUC 0.706; 95%CI 0.526-0.886), but not a non-SCD (AUC 0.527; 95%CI 0.303-0.75). SVG elevation more accurately predicted SCD if the ECG was recorded 6 months before SCD (AUC 0.706; 95%CI 0.526-0.886) than 2 years before SCD (AUC 0.608; 95%CI 0.515-0.701). Within the first 3 months after ECG recording, only SVG azimuth improved reclassification of the risk beyond clinical risk factors: 18% of SCD events were reclassified from low or intermediate risk to a high-risk category. QRS-T angle was the strongest long-term predictor of SCD (AUC 0.710; 95%CI 0.668-0.753 for ECG recorded within 10 years before SCD).

CONCLUSION

Short-term and long-term predictive accuracy of ECG biomarkers of SCD differed, reflecting differences in transient vs. persistent SCD substrates. The dynamic predictive accuracy of ECG biomarkers should be considered for competing SCD risk scores. The distinction between markers predicting short-term and long-term events may represent the difference between markers heralding SCD (triggers or transient substrates) versus markers identifying persistent substrate.

Importance of the heart vector origin point definition for an ECG analysis: The Atherosclerosis Risk in Communities (ARIC) study

AIM

Our goal was to investigate the effect of a global XYZ median beat construction and the heart vector origin point definition on predictive accuracy of ECG biomarkers of sudden cardiac death (SCD).

METHODS

Atherosclerosis Risk In Community study participants with analyzable digital ECGs were included (n = 15,768; 55% female, 73% white, mean age 54.2 ± 5.8 y). We developed an algorithm to automatically detect the heart vector origin point on a median beat. Three different approaches to construct a global XYZ beat and two methods to locate origin point were compared. Global electrical heterogeneity was measured by sum absolute QRST integral (SAI QRST), spatial QRS-T angle, and spatial ventricular gradient (SVG) magnitude, azimuth, and elevation. Adjudicated SCD served as the primary outcome.

RESULTS

There was high intra-observer (kappa 0.972) and inter-observer (kappa 0.984) agreement in a heart vector origin definition between an automated algorithm and a human. QRS was wider in a median beat that was constructed using R-peak alignment than in time-coherent beat (88.1 ± 16.7 vs. 83.7 ± 15.9 ms; P < 0.0001), and on a median beat constructed using QRS-onset as a zeroed baseline, vs. isoelectric origin point (86.7 ± 15.9 vs. 83.7 ± 15.9 ms; P < 0.0001). ROC AUC was significantly larger for QRS, QT, peak QRS-T angle, SVG elevation, and SAI QRST if measured on a time-coherent median beat, and for SAI QRST and SVG magnitude if measured on a median beat using isoelectric origin point.

CONCLUSION

Time-coherent global XYZ median beat with physiologically meaningful definition of the heart vector's origin point improved predictive accuracy of SCD biomarkers.

Resource and Response Type Classification for Consumer Health Question Answering

Health question answering systems often depend on the initial step of question type classification. Practitioners face several modeling choices for this component alone. We evaluate the effectiveness of different modeling choices in both the embeddings and architectural hyper-parameters of the classifier. In the process, we achieve improved performance over previous methods, achieving a new best 5-fold accuracy of 85.3% on the GARD dataset. The contribution of this work is to evaluate the performance of sentence classification methods on the task of consumer health question type classification and to contribute a dataset of 2,882 medical questions annotated for question type.

Vectorcardiogram in athletes: The Sun Valley Ski Study

BACKGROUND

Global electrical heterogeneity (GEH) is associated with sudden cardiac death (SCD) in adults of 45 years and above. However, GEH has not been previously measured in young athletes. The goal of this study was to establish a reference for vectorcardiograpic (VCG) metrics in male and female athletes.

METHODS

Skiers (n = 140; mean age 19.2 ± 3.5 years; 66% male, 94% white; 53% professional athletes) were enrolled in a prospective cohort. Resting 12-lead ECGs were interpreted per the International ECG criteria. Associations of age, sex, and athletic performance with GEH were studied.

RESULTS

In age and training level-adjusted analyses, male sex was associated with a larger T vector [T peak magnitude +186 (95% CI 106-266) µV] and a wider spatial QRS-T angle [+28.2 (17.3-39.2)°] as compared to women. Spatial QRS-T angle in the ECG left ventricular hypertrophy (LVH) voltage group (n = 21; 15%) and normal ECG group did not differ (67.7 ± 25.0 vs. 66.8 ± 28.2; p = 0.914), suggesting that ECG LVH voltage in athletes reflects physiological remodeling. In contrast, skiers with right ventricular hypertrophy (RVH) voltage (n = 26, 18.6%) had wider QRS-T angle (92.7 ± 29.6 vs. 66.8 ± 28.2°; p = 0.001), larger SAI QRST (194.9 ± 30.2 vs. 157.8 ± 42.6 mV × ms; p < 0.0001), but similar peak SVG vector magnitude (1976 ± 548 vs. 1939 ± 395 µV; p = 0.775) as compared to the normal ECG group. Better athletic performance was associated with the narrower QRS-T angle. Each 10% worsening in an athlete's Federation Internationale de' Ski downhill ranking percentile was associated with an increase in spatial QRS-T angle by 2.1 (95% CI 0.3-3.9) degrees (p = 0.013).

CONCLUSION

Vectorcardiograpic adds nuances to ECG phenomena in athletes.

The utility of routine clinical 12-lead ECG in assessing eligibility for subcutaneous implantable cardioverter defibrillator

INTRODUCTION

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is a life-saving device. Recording of a specialized 3-lead electrocardiogram (ECG) is required for S-ICD eligibility assessment. The goals of this study were: (1) evaluate the effect of ECG filtering on S-ICD eligibility, and (2) simplify S-ICD eligibility assessment by development of an S-ICD ineligibility prediction tool, which utilizes the widely available routine 12-lead ECG.

METHODS AND RESULTS

Prospective cross-sectional study participants [n = 68; 54% male; 94% white, with wide ranges of age (18-81 y), body mass index (19-53), QRS duration (66-150 ms), and left ventricular ejection fraction (37-77%)] underwent 12-lead supine, 3-lead supine and standing ECG recording. All 3-lead ECG recordings were assessed using the standard S-ICD pre-implantation ECG morphology screening. Backward, stepwise, logistic regression was used to build a model for 12-lead prediction of S-ICD eligibility. Select electrocardiogram waves and complexes: QRS, R-, S, and T-amplitudes on all 12 leads, averaged QT interval, QRS duration, and R/T ratio in the lead with the largest T wave (R/T_max) were included as predictors. The effect of ECG filtering on ECG morphology was evaluated. A total of 9 participants (13%) failed S-ICD screening prior to filtering. Filtering at 3-40 Hz, similar to the S-ICD default, reduced S-ICD ineligibility to 4%. A regression model that included R_II, S_II-aVL, T_{I, II, aVL, aVF, V3-V6}, and R/T_max perfectly predicted S-ICD eligibility, with an Area Under the Receiver Operating Characteristic Curve of 1.0.

CONCLUSION

Routine clinical 12-lead ECG can be used to predict S-ICD eligibility. ECG filtering may improve S-ICD eligibility.

A retrospective review of an epidural blood patch database: the incidence of epidural blood patch associated with obstetric neuraxial anesthetic techniques and the effect of blood volume on efficacy

BACKGROUND

The optimal volume of blood required to treat post-dural puncture headache remains in question. In our institution a target volume of 30mL is used for an epidural blood patch unless the patient experiences pain during injection.

METHODS

The institutional database was retrospectively reviewed for epidural blood patch and delivery statistics over a 15-year period to determine if the volume of blood administered during the procedure directly correlated with the number of epidural blood patches administered. The primary endpoint was defined as the need for a repeat epidural blood patch.

RESULTS

There were 466 epidural blood patches performed on 394 patients, associated with 84 804 obstetric neuraxial procedures. Thirty-two percent (95% CI 28.3 to 34.9%) of patients who had an inadvertent dural puncture with an epidural needle received an epidural blood patch versus 0.19% (0.16% to 0.22%) of patients who received neuraxial anesthesia with no documented dural puncture with an epidural needle. All patients experienced relief of post-dural puncture headache, although 17% required two and 1.5% required three epidural blood patches. The mean±SD volume of blood administered was 20.5±5.4mL and only 35 patients (8.9%) received 30mL.

CONCLUSION

Increasing blood volumes up to 30mL did not reduce the need for repeat epidural blood patch. Although the optimal volume of blood to administer during epidural blood patch placement remains unknown, our institution will continue to administer up to 30mL or until the patient experiences pain during epidural injection.

Sorgoleone from root exudate inhibits mitochondrial functions

The aim of this investigation was to determine if sorgoleone (SGL), a hydrophobic compound inSorghum bicolor (L.) Moench root exudate, interferes with mitochondrial functions. Tests were conducted on mitochondria isolated from etiolated soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) seedlings. The data show SGL is a potent inhibitor of state 3 and state 4 respiration rates in both soybean and corn. Using either NADH, succinate, or malate as substrate, the I50 was about 0.5μM SGL for state 3 and 5.0μM for state 4 based on 0.3-0.5 mg mitochondrial protein. Absorption spectra indicate SGL blocks electron transport at theb-c 1 complex. These data show that disruption of mitochondrial function may be a mechanism of SGL-mediated growth inhibition previously reported and demonstrate a probable role of SGL inSorghum allelopathy.

Placental transfer of (125)Iodinated humanized immunoglobulin G2Δa in the Sprague Dawley rat

Antibody-like biopharmaceuticals cross the placenta by utilizing transport pathways available for transfer of maternal antibodies to the conceptus. To characterize the timing and magnitude of this transfer in the rat, embryo/fetal biodistribution of maternally administered radiolabeled humanized IgG2 was quantified over the course of gestation using gamma counting and whole body autoradiography. The result was humanized IgG2 found in rat embryo/fetal tissues as early as gestation day 11 with a >1000-fold increase in the amount of total IgG2 by day 21. The concentration of IgG2 in rat embryo/fetal tissues generally remained unchanged from gestation day 11 to 17 with a slight increase from day 17 to 21. In addition, fetal-maternal tissue concentration ratios remained stable during organogenesis with a slight increase from gestation day 17 to 21. Based on the empirical amount of antibody present in the embryo/fetus during specific developmental windows, direct antibody binding to biological targets could potentially result in adverse developmental outcomes.

Significantly enhanced energy output from 3D ordered macroporous structured Fe2O3/Al nanothermite film

A three-dimensionally ordered macroporous Fe(2)O(3)/Al nanothermite membrane has been prepared with a polystyrene spheres template. The nanothermite, with an enhanced interfacial contact between fuel and oxidizer, outputs 2.83 kJ g(-1) of energy. This is significantly more than has been reported before. This approach, fully compatible with MEMS technology, provides an efficient way to produce micrometer thick three-dimensionally ordered nanostructured thermite films with overall spatial uniformity. These exciting achievements will greatly facilitate potential for the future development of applications of nanothermites.

Steady and oscillatory fluid flows produce a similar osteogenic phenotype

Mechanical loading induces positive changes in the skeleton due to direct effects on bone cells, which may include regulation of transcription factors that support osteoblast differentiation and function. Flow effects on osteoblast transcription factors have generally been evaluated after short exposures. In this work, we assayed flow effects on osteogenic genes at early and late time points in a preosteoblast (CIMC-4) cell line and evaluated both steady and oscillatory flows. Four hours of steady unidirectional flow decreased the level of RANKL mRNA 53 ± 7% below that of nonflowed cells, but increases in Runx2 and osterix mRNA (44 ± 22% and 129 ± 12%, respectively) were significant only after 12-19 h of continuous flow. Late flow effects on RANKL and osterix were also induced by an intermittent flow-rest protocol (four cycles of 1 h on/1 h off + overnight rest). Four hours of oscillatory flow decreased RANKL mRNA at this early time point (63 ± 2%) but did not alter either osterix or Runx2. When oscillatory flow was delivered using the intermittent flow-rest protocol, Runx2 and osterix mRNA increased significantly (85 ± 19% and 161 ± 22%, respectively). Both β-catenin and ERK1/2, known to be involved in RANKL regulation, were rapidly activated by steady flow. Inhibition of flow-activated ERK1/2 prevented the increase in osterix mRNA but not Runx2; Runx2 phosphorylation was increased by flow, an effect which likely contributes to osterix induction. This work shows that both steady and oscillatory fluid flows can support enhancement of an osteogenic phenotype.

Subjective well-being of adults with homozygous sickle cell disease in Jamaica

OBJECTIVES

This study compared the subjective well-being of adults with homozygous sickle cell (SS) disease to a matched group of healthy adult peers. The differential influence of sociodemographic factors on the subjective well-being of Sickle Cell patients was also examined.

METHODS

The Ferran and Powers Quality of Life Index and the Positive and Negative Affect Schedule were used to assess subjective well-being. Seventy-five homozygous sickle cell (SS) disease patients and sixty-seven matched controls (adults with normal haemoglobin: AA) from the Sickle Cell Disease Cohort Study in Jamaica were interviewed. Analysis of variance (ANOVA) was used to examine differences between the groups.

RESULT

Patients with Sickle cell (SS) disease were less satisfied than matched controls with their lives overall, their health and functioning, social and economic situation and psychological functioning. Sickle cell disease patients reported lower levels of positive affect but similar levels of negative affect as controls. Unemployed sickle cell disease patients were less satisfied than all other adults with their lives overall, health and functioning, psychological functioning and social and economic situation. Sickle cell disease patients with lower occupational status were less satisfied with their family life than all other adults.

CONCLUSIONS

These findings suggest that subjective well-being is compromised in patients with homozygous sickle cell disease. These patients may benefit from interventions designed to improve their subjective well-being.

Hospitalizations for tuberculosis in New York City: how many could be avoided?

OBJECTIVE

To determine which factors were associated with hospitalization for tuberculosis (TB) in New York City (NYC), United States, and to estimate the proportion of potentially avoidable admissions.

DESIGN

Patients diagnosed with TB from April to June 2003 were included. Records of hospitalized patients were reviewed to determine whether hospitalization was appropriate. Hospitalization was considered appropriate if patients met ≥1 of the NYC health department hospitalization criteria and/or needed hospitalization per study physicians' judgment. The association of patient characteristics with hospitalization and with having an inappropriate hospitalization was evaluated using multivariate analyses. TB cases from 2008 were also evaluated to determine whether more recent cases had similar associations with hospitalization.

RESULTS

Of 315 patients diagnosed with TB during the study, 226 (72%) were hospitalized. Hospitalized patients were more likely to have a cavitary chest radiograph (adjusted odds ratio [aOR] 8.11, 95%CI 1.82-36.20), abuse alcohol/drugs (aOR 6.53, 95%CI 2.06-20.67), be Black non-Hispanic (aOR 3.05, 95%CI 1.00-9.38), have unknown human immunodeficiency virus status (aOR 2.67, 95%CI 1.24-5.76), and to have been first evaluated by a private medical provider (aOR 2.37, 95%CI 1.11-5.08). Eighty-seven (38%) of the hospitalizations may have been inappropriate; foreign-born (aOR 3.16, 95%CI 1.39-7.14) and acid-fast bacilli sputum smear-positive (aOR 2.49, 95%CI 1.18-5.23) patients were more likely to be hospitalized inappropriately.

CONCLUSION

Many TB hospitalizations in NYC may be avoidable. Existing guidelines for diagnosing and managing cases as out-patients need to be put into practice.

Effect of intermittent fasting on prostate cancer tumor growth in a mouse model

Caloric restriction (CR) has been shown to have anti-cancer properties. However, CR may be difficult to apply in humans secondary to compliance and potentially deleterious effects. An alternative is intermittent CR, or in the extreme case intermittent fasting (IF). In a previous small pilot study, we found 2 days per week of IF with ad libitum feeding on the other days resulted in trends toward prolonged survival of mice bearing prostate cancer xenografts. We sought to confirm these findings in a larger study. A total of 100 (7- to 8-week-old) male severe combined immunodeficiency mice were injected subcutaneously with 1 × 10(5) LAPC-4 prostate cancer cells. Mice were randomized to either ad libitum Western Diet (44% carbohydrates, 40% fat and 16% protein) or ad libitum Western Diet with twice-weekly 24 h fasts (IF). Tumor volumes and mouse bodyweights were measured twice weekly. Mice were killed when tumor volumes reached 1000 mm(3). Serum and tumor were collected for analysis of the insulin/insulin-like growth factor 1 (IGF-1) hormonal axis. Overall, there was no difference in mouse survival (P=0.37) or tumor volumes (P ≥ 0.10) between groups. Mouse body weights were similar between arms (P=0.84). IF mice had significantly higher serum IGF-1 levels and IGF-1/IGFBP-3 ratios at killing (P<0.001). However, no difference was observed in serum insulin, IGFBP-3 or tumor phospho-Akt levels (P ≥ 0.39). IF did not improve mouse survival nor did it delay prostate tumor growth. This may be secondary to metabolic adaptations to the 24 h fasting periods. Future studies are required to optimize CR for application in humans.

UV inhibits allergic airways disease in mice by reducing effector CD4 T cells

BACKGROUND

In human asthma, and experimental allergic airways disease in mice, antigen-presenting cells and CD4(+) effector cells at the airway mucosa orchestrate, and CD4(+)CD25(+) regulatory T cells attenuate, allergen immunity. UV irradiation of skin before sensitization with ovalbumin (OVA) causes significantly reduced asthma-like responses in respiratory tissues.

OBJECTIVE

To determine whether UV-induced changes in CD11c(+) cells, CD4(+)CD25(+) effector cells or CD4(+)CD25(+) regulatory cells in the trachea and airway draining lymph nodes (ADLNs) were responsible for reduced allergic airways disease.

METHODS

The phenotype and function of CD11c(+) cells and CD4(+)CD25(+) cells in the trachea and ADLNs of UV- and non-irradiated, OVA-sensitized mice was examined 24 h after a single exposure to aerosolized OVA.

RESULTS

No changes in the function of CD11c(+) cells from UV-irradiated mice were observed. CD4(+)CD25(+) cells from UV-irradiated, OVA-sensitized mice harvested 24 h after OVA aerosol proliferated less in response to OVA in vitro and were unable to suppress the proliferation of OVA-sensitized responder cells. This result suggested reduced activation of effector T cells in the airway mucosa of UV-irradiated, OVA-sensitized mice. To exclude regulatory cells of any type, there was similar proliferation in vivo to aerosolized OVA by CFSE-loaded, OVA-TCR-specific CD4(+) cells adoptively transferred into UV- and non-irradiated, OVA-sensitized mice. In addition, there was no difference in the expression of regulatory T cell markers (Foxp3, IL-10, TGF-beta mRNA). To examine effector T cells, ADLN cells from UV-irradiated, OVA-sensitized and -challenged mice were cultured with OVA. There was reduced expression of the early activation marker CD69 by CD4(+)CD25(+) cells, and reduced proliferation in the absence of the regulatory cytokine, IL-10.

CONCLUSION

Reduced allergic airways disease in UV-irradiated mice is due to fewer effector CD4(+)CD25(+) cells in the trachea and ADLNs, and not due to UV-induced regulatory cells.

Acoustical mimicry in a predatory social parasite of ants

Rapid, effective communication between colony members is a key attribute that enables ants to live in dominant, fiercely protected societies. Their signals, however, may be mimicked by other insects that coexist as commensals with ants or interact with them as mutualists or social parasites. We consider the role of acoustics in ant communication and its exploitation by social parasites. Social parasitism has been studied mainly in the butterfly genus Maculinea, the final instar larvae of which are host-specific parasites of Myrmica ants, preying either on ant grubs (predatory Maculinea) or being fed by trophallaxis (cuckoo Maculinea). We found similar significant differences between the stridulations of model queen and worker ant castes in both Myrmica sabuleti and Myrmica scabrinodis to that previously reported for Myrmica schencki. However, the sounds made by queens of all three Myrmica species were indistinguishable, and among workers, stridulations did not differ significantly in two of three species-pairs tested. Sounds recorded from the predatory caterpillars and pupae of Maculinea arion had similar or closer patterns to the acoustics of their host Myrmica sabuleti than those previously reported for the cuckoo Maculinea rebeli and its host Myrmica schencki, even though Maculinea rebeli caterpillars live more intimately with their host. We conclude that chemical mimicry enables Maculinea larvae to be accepted as colony members by worker ants, but that caterpillars and pupae of both predatory and cuckoo butterflies employ acoustical mimicry of queen ant calls to elevate their status towards the highest attainable position within their host's social hierarchy.

Effect of surface wettability on liquid density, structure, and diffusion near a solid surface

Molecular dynamics and Langevin dynamics simulations are used to elucidate the behavior of liquid atoms near a solid boundary. Correlations between the surface wettability and spatial variations in liquid density and structure are identified. The self-diffusion coefficient tensor is predicted, revealing highly anisotropic and spatially varying mass transfer phenomena near the solid boundary. This behavior affects self-diffusion at a range of time scales. Near a more-wetting surface, self-diffusion is impeded by strong solid-liquid interactions that induce sharp liquid density gradients and enhanced liquid structure. Conversely, near a less-wetting surface, where solid-liquid interactions are weaker, the liquid density is low, the atoms are disordered, and diffusion is enhanced. These findings suggest that altering the wettability of a micro- or nanochannel may provide a passive means for controlling the diffusion of select targets towards a functionalized surface and controlling the reaction rate in diffusion-limited reactions.

Increased genetic diversity as a defence against parasites is undermined by social parasites: Microdon mutabilis hoverflies infesting Formica lemani ant colonies

Genetic diversity can benefit social insects by providing variability in immune defences against parasites and pathogens. However, social parasites of ants infest colonies and not individuals, and for them a different relationship between genetic diversity and resistance may exist. Here, we investigate the genetic variation, assessed using up to 12 microsatellite loci, of workers in 91 Formica lemani colonies in relation to their infestation by the specialist social parasite Microdon mutabilis. At the main study site, workers in infested colonies exhibited lower relatedness and higher estimated queen numbers, on average, than uninfested ones. Additionally, estimated queen numbers were negatively correlated with estimated average numbers of mates per queen within infested colonies. At another site, infested colonies also exhibited significantly lower worker relatedness, and estimated queen numbers were comparable in trend. In contrast, in two populations of F. lemani where M. mutabilis was absent, relatedness within colonies was high (40 and 90% with R>0.6). While high genetic variation can benefit social insects by increasing their resistance to pathogens, there may be a cost in the increased likelihood of infiltration by social parasites owing to greater variation in nestmate recognition cues. This study provides the first empirical test of this hypothesis.

Outcome after three years of laronidase enzyme replacement therapy in a patient with Hurler syndrome

Enzyme replacement therapy (ERT) with laronidase, recombinant alpha-L-iduronidase, for mucopolysaccharidosis type I (MPS I) has been clinically available since April 2003. Pre-approval studies were performed on patients with the more attenuated forms of MPS I, Hurler-Scheie and Scheie syndromes. The clinical efficacy of laronidase on the severe form of MPS I, Hurler syndrome, is not well known. We present a patient with Hurler syndrome who has been treated with laronidase for 3 years. Clinically, the patient demonstrated improvement in urinary glycosaminoglycan (GAG) levels and hepatomegaly, but continued to experience decline in respiratory status, musculoskeletal and spinal involvement, and developmental skills. Overall, the benefit of ERT with laronidase in advanced Hurler syndrome appeared to be minimal in this patient.

Host propagation permits extreme local adaptation in a social parasite of ants

The Red Data Book hoverfly species Microdon mutabilis is an extreme specialist that parasitises ant societies. The flies are locally adapted to a single host, Formica lemani, more intimately than was thought possible in host-parasite systems. Microdon egg survival plummeted in F. lemani colonies > 3 km away from the natal nest, from c. 96% to 0% to < 50%, depending on the hoverfly population. This is reflected in the life-time dispersal of females, measured at < 2 m, resulting in oviposition back into the same ant nests for generation after generation. To counter destabilizing effects on the host, Microdon manipulates the social dynamics of F. lemani by feeding selectively on ant eggs and small larvae, which causes surviving larvae to switch development into queens. Infested colonies rear double the number of new queens, thus propagating the vulnerable local genotype and compensating for damage to the host colonies. The consequences of such extreme host specificity for insect conservation are discussed.

Isolation of quiescent and nonquiescent cells from yeast stationary-phase cultures

Quiescence is the most common and, arguably, most poorly understood cell cycle state. This is in part because pure populations of quiescent cells are typically difficult to isolate. We report the isolation and characterization of quiescent and nonquiescent cells from stationary-phase (SP) yeast cultures by density-gradient centrifugation. Quiescent cells are dense, unbudded daughter cells formed after glucose exhaustion. They synchronously reenter the mitotic cell cycle, suggesting that they are in a G(0) state. Nonquiescent cells are less dense, heterogeneous, and composed of replicatively older, asynchronous cells that rapidly lose the ability to reproduce. Microscopic and flow cytometric analysis revealed that nonquiescent cells accumulate more reactive oxygen species than quiescent cells, and over 21 d, about half exhibit signs of apoptosis and necrosis. The ability to isolate both quiescent and nonquiescent yeast cells from SP cultures provides a novel, tractable experimental system for studies of quiescence, chronological and replicative aging, apoptosis, and the cell cycle.

D-2-hydroxyglutaric aciduria in three patients with proven SSADH deficiency: genetic coincidence or a related biochemical epiphenomenon?

Succinic semialdehyde dehydrogenase (SSADH) deficiency and D-2-hydroxyglutaric aciduria (D-2-HGA) are rare inborn errors of metabolism primarily revealed by urinary organic acid screening. Three patients with proven SSADH deficiency excreted, in addition to GHB considerable amounts of D-2-HG. We examined whether these patients suffered from two inborn errors of metabolism by measuring D-2-HG concentrations in the culture medium of cells from these patients. In addition, mutation analysis of the D-2-hydroxyglutarate dehydrogenase gene was performed. Normal concentrations of D-2-HG were measured in the culture media of fibroblasts or lymphoblasts derived from the three patients. In one patient, we found a heterozygous likely pathogenic mutation in the D-2-hydroxyglutarate dehydrogenase gene. These combined results argue against the hypothesis that the patients are affected with "primary" D-2-HGA in combination with their SSADH deficiency. Moderately increased levels of D-2-HG were also found in urine, plasma, and cerebrospinal fluid samples derived from 12 other patients with SSADH deficiency, revealing that D-2-HG is a common metabolite in this disease. The increase of D-2-HG in SSADH deficiency can be explained by the action of hydroxyacid-oxoacid transhydrogenase, a reversible enzyme that oxidases GHB in the presence of 2-ketoglutarate yielding SSA and D-2-HG.

The Third International Intercomparison on EPR Tooth Dosimetry: part 2, final analysis

The objective of the Third International Intercomparison on EPR Tooth Dosimetry was to evaluate laboratories performing tooth enamel dosimetry <300 mGy. Final analysis of results included a correlation analysis between features of laboratory dose reconstruction protocols and dosimetry performance. Applicability of electron paramagnetic resonance (EPR) tooth dosimetry at low dose was shown at two applied dose levels of 79 and 176 mGy. Most (9 of 12) laboratories reported the dose to be within 50 mGy of the delivered dose of 79 mGy, and 10 of 12 laboratories reported the dose to be within 100 mGy of the delivered dose of 176 mGy. At the high-dose tested (704 mGy) agreement within 25% of the delivered dose was found in 10 laboratories. Features of EPR dose reconstruction protocols that affect dosimetry performance were found to be magnetic field modulation amplitude in EPR spectrum recording, EPR signal model in spectrum deconvolution and duration of latency period for tooth enamel samples after preparation.

Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups

Conservative estimates suggest that 50-90% of the existing insect species on Earth have still to be discovered, yet the named insects alone comprise more than half of all known species of organism. With such poor baseline knowledge, monitoring change in insect diversity poses a formidable challenge to scientists and most attempts to generalize involve large extrapolations from a few well-studied taxa. Butterflies are often the only group for which accurate measures of change can be obtained. Four schemes, used successfully to assess change in British butterflies, that are increasingly being applied across the world are described: Red Data Books (RDB) list the best judgements of experts of the conservation status of species in their field of expertise; mapping schemes plot the changing distributions of species at scales of 1-100 km2; transect monitoring schemes generate time series of changes in abundance in sample populations of species on fixed sites across the UK; and occasional surveys measure the number, boundaries and size of all populations of a (usually RDB) species at intervals of 10-30 years. All schemes describe consistent patterns of change, but if they are to be more generally useful, it is important to understand how well butterflies are representative of other taxa. Comparisons with similarly measured changes in native bird and plant species suggest that butterflies have declined more rapidly that these other groups in Britain; it should soon be possible to test whether this pattern exists elsewhere. It is also demonstrated that extinction rates in British butterflies are similar to those in a range of other insect groups over 100 years once recording bias is accounted for, although probably lower than in aquatic or parasitic taxa. It is concluded that butterflies represent adequate indicators of change for many terrestrial insect groups, but recommended that similar schemes be extended to other popular groups, especially dragonflies, bumblebees, hoverflies and ants. Given institutional backing, similar projects could be employed internationally and standardized. Finally, a range of schemes designed to monitor change in communities of aquatic macro-invertebrates is described. Although designed to use invertebrates as a bio-indicator of water quality for human use, these programmes could be extended to monitor the 2010 biodiversity targets of the World Summit on Sustainable Development.

Parameters affecting EPR dose reconstruction in teeth

The aim of this paper is to analyze the lower limit of detection (LLD), linearity of dose response, variation of radiation sensitivity between different tooth enamel samples, and time/temperature stability of EPR biodosimetry in tooth enamel. The theoretical LLD is shown to be 0.46 mGy, which is far lower than the measured value of about 30 mGy. The main issues to lowering LLD are the differentiation of the radiation-induced component against the total EPR spectrum and the complex nature of the dose dependence of the EPR signal. The following questions are also discussed in detail: need for exfoliated or extracted teeth from persons of interest, accounting for background radiation contribution; conversion of tooth enamel absorbed dose to effective dose; accounting for internal exposure specifically from bone-seeking radionuclides. Conclusions on future development of EPR retrospective biodosimetry are made.

Spectrum file size optimization for EPR tooth dosimetry

Spectral acquisition time is one of the limiting factors in electron paramagnetic resonance (EPR) retrospective biodosimetry in teeth. Acquisition times for one sample can be from 2 to 4h. This problem is even more acute for in vivo EPR measurements in L-band. Patients cannot be expected to remain stationary for these lengths of time. In order to overcome this limitation, we investigated the dependence of EPR dose measurements on the number of data points in an EPR spectrum. We have shown that this number could be reduced from 1024 to 256 (factor of 4 reduction in spectral acquisition time) at 5 mT magnetic field sweep without a loss of precision in the dose measurements.

Biopharmaceuticals derived from genetically modified plants

Modern biotechnology has resulted in a resurgence of interest in the production of new therapeutic agents using botanical sources. With nearly 500 biotechnology products approved or in development globally, and with production capacity limited, the need for efficient means of therapeutic protein production is apparent. Through genetic engineering, plants can now be used to produce pharmacologically active proteins, including mammalian antibodies, blood product substitutes, vaccines, hormones, cytokines, and a variety of other therapeutic agents. Efficient biopharmaceutical production in plants involves the proper selection of host plant and gene expression system, including a decision as to whether a food crop or a non-food crop is more appropriate. Product safety issues relevant to patients, pharmaceutical workers, and the general public must be addressed, and proper regulation and regulatory oversight must be in place prior to commercial plant-based biopharmaceutical production. Plant production of pharmaceuticals holds great potential, and may become an important production system for a variety of new biopharmaceutical products.

Changes in chemical signature and host specificity from larval retrieval to full social integration in the myrmecophilous butterfly Maculinea rebeli

The ant social parasite, Maculinea rebeli shows high levels of host specificity at a regional scale. While 68-88% of caterpillars in the field are adopted by nonhost Myrmica ants, 95-100% of the butterflies emerge from the natural host M. schencki the following year. While retrieval of preadoption caterpillars is specific to the genus Myrmica, it does not explain differential survival with different Myrmica species. We present survival data with host and nonhost Myrmica species suggesting that, with nonhosts (M. sabuleti and M. rubra), survival depends on the physiological state of the colony. We also compared the similarities of the epicuticular surface hydrocarbon signatures of caterpillars that were reared by host and nonhost Myrmica for 3 weeks with those from tending workers. Counterintuitively, the hydrocarbons of postadoption caterpillars were more similar (78%, 73%) to the ant colony profiles of the nonhost species than were caterpillars reared in colonies of M. schencki (42% similarity). However, caterpillars from M. schencki nests that were then isolated for 4 additional days showed unchanged chemical profiles, whereas the similarities of those from nonhost colonies fell to 52 and 56%, respectively. Six compounds, presumably newly synthesized, were detected on the isolated caterpillars that could not have been acquired from M. sabuleti and M. rubra (nor occurred on preadoption caterpillars), five of which were found on the natural host M. schencki. These new compounds may relate to the high rank the caterpillars attain within the hierarchy of M. schencki societies. The same compounds would identify the caterpillars as intruders in non-schencki colonies, where their synthesis appeared to be largely suppressed. The ability to synthesize or suppress additional compounds once adopted explains the pattern of mortalities found among fully integrated caterpillars in Myrmica colonies of different species and physiological states.

Comparative losses of British butterflies, birds, and plants and the global extinction crisis

There is growing concern about increased population, regional, and global extinctions of species. A key question is whether extinction rates for one group of organisms are representative of other taxa. We present a comparison at the national scale of population and regional extinctions of birds, butterflies, and vascular plants from Britain in recent decades. Butterflies experienced the greatest net losses, disappearing on average from 13% of their previously occupied 10-kilometer squares. If insects elsewhere in the world are similarly sensitive, the known global extinction rates of vertebrate and plant species have an unrecorded parallel among the invertebrates, strengthening the hypothesis that the natural world is experiencing the sixth major extinction event in its history.

Effect of room illuminance on monitor black level luminance and monitor calibration

In this article we demonstrate the effect of room illuminance and surrounding monitor black level luminance on image quality for soft copy interpretation. Luminance values of a 10% central target and image quality evaluations and observer performance using a contrast-detail mammography (CDMAM) phantom demonstrate these effects. Our results indicate that high room illuminance has a more damaging effect on image quality when the surrounding monitor luminance is 0% to 5% of the maximum monitor luminance. The effect of room illuminance is less obvious when the surrounding monitor luminance is 20% of the maximum.

Genetic and clinical characterization of patients with an interstitial duplication 15q11-q13, emphasizing behavioral phenotype and response to treatment

The clinical significance of an interstitial duplication of (15)(q11-q13) remains unclear and controversial. The reported phenotypes vary widely and appear to be influenced by the parent of origin of the duplication. Aside from cases of dup(15) reported with autism, the behavioral phenotype of individuals with dup(15) has not been described. We present three families, two with intrachromosomal duplication (15)(q11-q13) ascertained because of developmental delay in a relative. Two families show clear evidence of multigenerational maternal inheritance. The individuals discussed in this paper have minor anomalies and developmental delays. In addition, we describe a behavioral phenotype which often includes attention deficit hyperactivity disorder (ADHD) and autistic spectrum disorder. Responses to medications used to manage these behaviors are also described, including a positive response to methylphenidate and a poor response to fluoxetine. The duplication in each presenting individual, and available family members, was investigated utilizing cytogenetic and molecular techniques including high resolution cytogenetics, fluorescence in situ hybridization (FISH), DNA methylation studies, and quantitative fluorescence PCR. High resolution cytogenetic techniques alone missed some cases, demonstrating the need to confirm results with other methods.

Seasonal variation in the niche, habitat availability and population fluctuations of a bivoltine thermophilous insect near its range margin

We investigated the niche requirements of the summer and autumn/spring generations of the bivoltine butterfly, Polyommatus bellargusRott., and their implications for population dynamics at sites occurring near its northern range margin. The larvae of this species are sedentary, and the turf height and shelter of Hippocrepis comosa foodplants selected for egg-laying accurately predict larval distributions within United Kingdom (UK) sites. We found a significant shift between the plants used for egg-laying in each generation, with the niche occupied by summer-feeding larvae being broader and different to the autumn one. Measurements of soil temperature confirmed that the short, sheltered foodplants selected by ovipositing females in autumn placed the autumn/spring-feeding generation of larvae in the warmest available microclimates within sites. In late spring, egg-laying females avoided the hottest spots but extended egg-laying into taller, less sheltered (relatively cool) turf where the microclimate was similar to that experienced by autumn/spring-feeding larvae. Using each generations' definition of niche requirement, we analysed surveys of foodplant populations available on 24 UK sites for P. bellargus, and estimated that nearly twice as many plants were available to the summer-feeding larvae compared to those feeding in the autumn. Annual adult population counts match these seasonal differences in site carrying capacity; first generation counts (from autumn-laid eggs) were generally half as abundant as in the second generation, and more variable. These results suggest that the seasonal cycle of niche switches represents an annual (autumn-spring) bottleneck for populations of this butterfly at its northern range margin. Under climate warming we predict that the inter-generational difference in niche availability, carrying capacity and population size will be reduced. We recommend revised management requirements for this threatened species under current and predicted climates in northern Europe.

Markedly elevated serum biotinidase activity may indicate glycogen storage disease type Ia

We report two children who presented with symptoms suggestive of biotinidase deficiency. Rather than deficiency, markedly elevated serum biotinidase activities were found. Based upon literature reports of elevated biotinidase activities in children with glycogen storage disease (GSD) type Ia, we considered the latter in our differential diagnosis and subsequently confirmed GSD type Ia in both patients by enzymatic testing. GSD type Ia should be considered in children with markedly elevated serum biotinidase activity.

A calibration approach to glandular tissue composition estimation in digital mammography

The healthy breast is almost entirely composed of a mixture of fatty, epithelial, and stromal tissues which can be grouped into two distinctly attenuating tissue types: fatty and glandular. Further, the amount of glandular tissue is linked to breast cancer risk, so an objective quantitative analysis of glandular tissue can aid in risk estimation. Highnam and Brady have measured glandular tissue composition objectively. However, they argue that their work should only be used for "relative" tissue measurements unless a careful calibration has been performed. In this work, we perform such a "careful calibration" on a digital mammography system and use it to estimate breast tissue composition of patient breasts. We imaged 0%, 50%, and 100% glandular-equivalent phantoms of varying thicknesses for a number of clinically relevant x-ray techniques on a digital mammography system. From these images, we extracted mean signal and noise levels and computed calibration curves that can be used for quantitative tissue composition estimation. In this way, we calculate the percent glandular composition of a patient breast on a pixelwise basis. This tissue composition estimation method was applied to 23 digital mammograms. We estimated the quantitative impact of different error sources on the estimates of tissue composition. These error sources include compressed breast height estimation error, residual scattered radiation, quantum noise, and beam hardening. Errors in the compressed breast height estimate contribute the most error in tissue composition--on the order of +/-7% for a 4 cm compressed breast height: The spatially varying scattered radiation will contribute quantitatively less error overall, but may be significant in regions near the skinline. It is calculated that for a 4 cm compressed breast height, a residual scatter signal error is mitigated by approximately sixfold in the composition estimate. The error in composition due to the quantum noise, which is the limiting noise source in the system, is shown to be less than 1% glandular for most breasts.