Impulsivity, suicidal thoughts, psychological distress, and religiosity in adolescents and young adults.

Background: Impulsivity is associated with suicidal acts and ideation, whereas higher religious commitment has been identified as a potential protective factor linked to lower suicidal ideation. Objectives: We examined the extent to which higher religious commitment is associated with lower suicidal ideation and whether religious commitment modifies the relationship between impulsivity and suicidal ideation. Methods: Adolescent and young adult males, with a prior history of suicidal act and ideations, completed standardized questionnaires [i.e., Beck Scale for Suicidal Ideation (BSS), Barratt Impulsivity Scale-II (BIS-II), Depression Anxiety Stress Scale (DASS), and Religious Commitment Inventory-10 (RCI-10)], to assess impulsivity, suicidal ideation, distress, and religious commitment. Regression and mediation analyses were performed to investigate the relationships among impulsivity, religious commitment, and suicidal ideation. Results: Of the 747 study participants (mean age 18.8 years, SD = 4.1), 151 (20.2%) had a history of suicidal acts and 177 (23.7%) had a history of suicidal ideation. Non-planning impulsivity (predictor) was inversely associated with religious commitment (r = -0.33, p < 0.01), and religious commitment (mediator) was inversely related to suicidal ideation (outcome) (r = -0.32, p < 0.01). These findings remained statistically significant when controlling for either religious commitment or non-planning impulsivity, as appropriate. Higher religious commitment reduced the association between non-planning impulsivity and suicidal ideation (p < 0.01). Conclusion: The findings highlight the potential for cultivating spirituality to buffer against higher suicidal ideation, and thus could be considered as an additional therapeutic strategy for individuals with higher levels of impulsivity and co-morbid suicidal ideation.

Validation of ELISA assays for the calculation of FLC indices for the diagnosis of intrathecal immunoglobulin synthesis.

OBJECTIVES: Define the cutoff thresholds of the Kappa (K) and Lambda (L) free light chains (FLC) indices for the detection of intrathecal immunoglobulin synthesis (IIS) using the new K and L FLC ELISA from SEBIA. The reference technique, which is not readily standardized between laboratories, is based on the demonstration of oligoclonal banding (OCB) in cerebrospinal fluid (CSF) which is absent in serum. For the past 6 years, we have also routinely calculated the K FLC index using The Binding Site (TBS) reagents on an Optilite instrument, an approach increasingly used as an alternative and/or a complement to electrophoretic analysis. METHODS: We analyzed 391 serum/CSF pairs divided into three groups. The first group were cases without OCB and with normal albumin CSF/serum ratio (n=174). The second group were cases with specific OCB (n=73). The last group included patients with increased albumin CSF/sera ratio without OCB (n=142). RESULTS: Analysis of the first group determined that the cutoffs for detection of IIS are respectively 2.55 and 1.02 for the K FLC and L FLC indices. Of the 73 cases with IIS, only 2 had a K FLC index below this threshold (sensitivity of 97.26%), while 16 out of 73 cases (78.08%) and 13 out of 72 cases (81.94%) had an IgG and L FLC index below the cutoffs, respectively. Additionally, we illustrate equivalent performances for prediction of the presence of OCB between SEBIA and TBS methods. CONCLUSIONS: Sebia K FLC and L FLC assays are adequate alternative methods for the diagnosis of IIS.

Lenvatinib in multimodal therapy for unresectable radioactive iodine-naïve differentiated thyroid cancer: A case report with literature review.

BACKGROUND: Patients with unresectable or metastatic differentiated thyroid carcinoma (DTC) are rare and require individualized therapy. This may require approaches not typically used in resectable disease. We report a patient treated with lenvatinib and external beam radiation therapy. CASE: An 87-year-old woman presented with cT4N1aM1 papillary thyroid carcinoma with tracheal invasion. She was not a candidate for surgery, radioactive-iodine, or radiation, so a trial of lenvatinib was offered. Her tumor showed clinical, biochemical, and radiological response after 5 months of lenvatinib, and she subsequently received external beam radiation. She enjoys good quality of life without evidence of cancer progression off therapy 21 months post-initiation of treatment. CONCLUSION: Lenvatinib may be effective in RAI-naïve advanced DTC patients as a component of individualized multimodal therapy when conventional options are not feasible.

Racial/Ethnic Disparities in Hospital Admissions from COVID-19 and Determining the Impact of Neighborhood Deprivation and Primary Language.

BackgroundDespite past and ongoing efforts to achieve health equity in the United States, persistent disparities in socioeconomic status along with multilevel racism maintain disparate outcomes and appear to be amplified by COVID-19. ObjectiveMeasure socioeconomic factors and primary language effects on the risk of COVID-19 severity across and within racial/ethnic groups. DesignRetrospective cohort study. SettingHealth records of 12 Midwest hospitals and 60 clinics in the U.S. between March 4, 2020 to August 19, 2020. PatientsPCR+ COVID-19 patients. ExposuresMain exposures included race/ethnicity, area deprivation index (ADI), and primary language. Main Outcomes and MeasuresThe primary outcome was COVID-19 severity using hospitalization within 45 days of diagnosis. Logistic and competing-risk regression models (censored at 45 days and accounting for the competing risk of death prior to hospitalization) assessed the effects of neighborhood-level deprivation (using the ADI) and primary language. Within race effects of ADI and primary language were measured using logistic regression. Results5,577 COVID-19 patients were included, 866 (n=15.5%) were hospitalized within 45 days of diagnosis. Hospitalized patients were older (60.9 vs. 40.4 years, p<0.001) and more likely to be male (n=425 [49.1%] vs. 2,049 [43.5%], p=0.002). Of those requiring hospitalization, 43.9% (n=381), 19.9% (n=172), 18.6% (n=161), and 11.8% (n=102) were White, Black, Asian, and Hispanic, respectively. Independent of ADI, minority race/ethnicity was associated with COVID-19 severity; Hispanic patients (OR 3.8, 95% CI 2.72-5.30), Asians (OR 2.39, 95% CI 1.74-3.29), and Blacks (OR 1.50, 95% CI 1.15-1.94). ADI was not associated with hospitalization. Non-English speaking (OR 1.91, 95% CI 1.51-2.43) significantly increased odds of hospital admission across and within minority groups. ConclusionsMinority populations have increased odds of severe COVID-19 independent of neighborhood deprivation, a commonly suspected driver of disparate outcomes. Non-English-speaking accounts for differences across and within minority populations. These results support the continued concern that racism contributes to disparities during COVID-19 while also highlighting the underappreciated role primary language plays in COVID-19 severity across and within minority groups. Key PointsO_ST_ABSQuestionC_ST_ABSDoes socioeconomic factors or primary language account for racial disparities in COVID-19 disease severity? FindingsIn this observational study of 5,577 adults, race/ethnicity minorities and non-English as a primary language, independent of neighborhood-level deprivation, are associated with increased risk of severe COVID-19 disease. MeaningSocioeconomic factors do not account for racial/ethnic disparities related to COVID-19 severity which supports further investigation into the racism and highlights the need to focus on our non-English speaking populations.

Characterizing COVID-19 Clinical Phenotypes and Associated Comorbidities and Complication Profiles

Background: There is limited understanding of heterogeneity in outcomes across hospitalized patients with coronavirus disease 2019 (COVID-19). Identification of distinct clinical phenotypes may facilitate tailored therapy and improve outcomes. Objective: Identify specific clinical phenotypes across COVID-19 patients and compare admission characteristics and outcomes. Design, Settings, and Participants: Retrospective analysis of 1,022 COVID-19 patient admissions from 14 Midwest U.S. hospitals between March 7, 2020 and August 25, 2020. Methods: Ensemble clustering was performed on a set of 33 vitals and labs variables collected within 72 hours of admission. K-means based consensus clustering was used to identify three clinical phenotypes. Principal component analysis was performed on the average covariance matrix of all imputed datasets to visualize clustering and variable relationships. Multinomial regression models were fit to further compare patient comorbidities across phenotype classification. Multivariable models were fit to estimate the association between phenotype and in-hospital complications and clinical outcomes. Main outcomes and measures: Phenotype classification (I, II, III), patient characteristics associated with phenotype assignment, in-hospital complications, and clinical outcomes including ICU admission, need for mechanical ventilation, hospital length of stay, and mortality. Results: The database included 1,022 patients requiring hospital admission with COVID-19 (median age, 62.1 [IQR: 45.9-75.8] years; 481 [48.6%] male, 412 [40.3%] required ICU admission, 437 [46.7%] were white). Three clinical phenotypes were identified (I, II, III); 236 [23.1%] patients had phenotype I, 613 [60%] patients had phenotype II, and 173 [16.9%] patients had phenotype III. When grouping comorbidities by organ system, patients with respiratory comorbidities were most commonly characterized by phenotype III (p=0.002), while patients with hematologic (p<0.001), renal (p<0.001), and cardiac (p<0.001) comorbidities were most commonly characterized by phenotype I. The adjusted odds of respiratory (p<0.001), renal (p<0.001), and metabolic (p<0.001) complications were highest for patients with phenotype I, followed by phenotype II. Patients with phenotype I had a far greater odds of hepatic (p<0.001) and hematological (p=0.02) complications than the other two phenotypes. Phenotypes I and II were associated with 7.30-fold (HR: 7.30, 95% CI: (3.11-17.17), p<0.001) and 2.57-fold (HR: 2.57, 95% CI: (1.10-6.00), p=0.03) increases in the hazard of death, respectively, when compared to phenotype III. Conclusion: In this retrospective analysis of patients with COVID-19, three clinical phenotypes were identified. Future research is urgently needed to determine the utility of these phenotypes in clinical practice and trial design.

Mechanical characterisation of the lateral collateral ligament complex of the ankle at realistic sprain-like strain rates.

BACKGROUND: Synthetic interventions continue to evolve with the progression made in materials science, surgical technologies and surgical methods. To facilitate the evolution of synthetic devices for lateral ankle repair a better understanding of the mechanical properties and failure mechanisms of the lateral collateral ligament (LCL) complex is required. This study aimed to improve understanding of the mechanical properties and failure modes of the LCL complex at strain rates representative of sprain. METHOD: The LCLs were dissected from six human cadavers to produce individual bone-ligament-bone specimens. A mechanical testing device uni-axially loaded the ligaments in tension. Initially, preconditioning between 2 N and a load value corresponding to 3.5% strain was conducted for 15 cycles, before extension to failure at strain rate of 100%.s-1. The results were stratified by age, weight and body mass index (BMI) to explore potential correlations with ligament ultimate failure load or ligament stiffness. RESULTS: The mean ultimate failure loads and the 95% confidence intervals for the ATFL, calcaneofibular (CFL) and posterior talofibular (PTFL) ligaments were 263.6 ± 164.3 N, 367.8 ±â€¯79.8 N and 351.4 ± 110.8 N, respectively. A strong positive Pearson correlation was found between BMI and ultimate failure load of the CFL (r = 0.919; P = .01). A non-significant relationship was found between the mechanical properties and both age and weight. The ATFL avulsed from the fibula four times, the CFL avulsed from the fibula twice, the PTFL avulsed from the talus twice and all remaining failures were mid-substance. CONCLUSION: The results identify the forces required to induce failure of the individual ligaments of the LCL complex and the related failure modes of individual ligaments. A correlation may exist between BMI and the ultimate failure load of the CFL and PTFL, although a greater sample size is required for confirmation.

The Effect of Platform-Switching Plus Laser Grooving on Peri-implant Hard and Soft Tissue Level: A Randomized, Controlled, Blinded Clinical Trial.

Twenty patients were randomly assigned to receive either a platform-switched or platform-matched implant to replace a single maxillary anterior tooth. Primary outcome variables were the implant interproximal bone loss, facial recession, and papilla fill at 12 months. The platform-switched group showed crestal bone loss of 0.1 ± 0.3 (mesial) and 0 mm (distal) while the platform-matched group showed losses of 0.6 ± 0.5 mm (mesial) and 0.7 ± 0.7 mm (distal) (P < .05). Facial recessions for the platform-switched and platform-matched groups were 0.1 ± 0.3 mm and 0.4 ± 0.8 mm, respectively.

Negative affect moderates the effect of social rejection on frontal and anterior cingulate cortex activation in borderline personality disorder.

Patients with borderline personality disorder (BPD) have a heightened sensitivity to social exclusion. Experimental manipulations have produced inconsistent findings and suggested that baseline negative affect (NA) might influence the experience of exclusion. We administered a standardized social exclusion protocol (Cyberball paradigm) in BPD (n = 39) and age-matched and sex-matched healthy controls (n = 29) to investigate the association of NA on social exclusion and activation in brain regions previously implicated in this paradigm. Compared with controls, patients with BPD showed higher activation during social exclusion in the anterior cingulate cortex (ACC), the medial prefrontal cortex (mPFC), and in the right precuneus. Prescan NA ratings were associated with higher brain activation in the ACC and mPFC over all conditions, and post hoc t tests revealed that differences between the groups were only significant when controlling for NA. Brain activation during exclusion was correlated with NA separately for each group. Only BPD patients showed a significant association of NA and exclusion related precuneus activation (r = .52 p = .001). Additionally, BPD patients experienced less feelings of belonging compared with a healthy control (HC) group during inclusion and exclusion, although they estimated their ball possessions significantly higher than did the HC. These findings suggest that baseline NA has a crucial impact on Cyberball-related brain activation. The results underscore the importance of considering levels of NA in social exclusion protocols for participants high in this trait.

Pay for Performance: Are Hospitals Becoming More Efficient in Improving Their Patient Experience?

The Centers for Medicare & Medicaid Services (CMS) changed the way hospitals interact with patients when it implemented a pay-for-performance (P4P) system. Under this system, a financial reward or penalty is based in part on measures of patient experience. The program seeks to reward healthcare providers who expand their focus from solely delivering a highly technical set of services that improves the patient's health to creating an atmosphere that makes hospitalization more humane and respectful of patients' values and preferences. Refocusing priorities requires capital investment in more "patient-friendly" facilities or funding staff training programs. This study seeks to determine whether a relationship exists between inpatient costs and the score for "overall rating of hospital" (ORH) on the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) hospital version survey. Second, if a relationship exists, the study examines how that relationship changed during the time of CMS' implementation of its P4P program. The study's findings suggest that higher-cost hospitals have higher levels of positive patient experiences, after controlling for other variables. Importantly, the research findings indicate that hospitals are becoming more efficient in delivering care associated with higher levels of patient experience, coinciding with implementation of the P4P program.

Effect of prenatal alcohol exposure on bony craniofacial development: a mouse MicroCT study.

Craniofacial bone dysmorphology is an important but under-explored potential diagnostic feature of fetal alcohol spectrum disorders. This study used longitudinal MicroCT 3D imaging to examine the effect of prenatal alcohol exposure on craniofacial bone growth in a mouse model. C57BL/6J dams were divided into 3 groups: alcohol 4.2% v/v in PMI® liquid diet (ALC), 2 weeks prior to and during pregnancy from embryonic (E) days 7-E16; pair-fed controls (PF), isocalorically matched to the ALC group; chow controls (CHOW), given ad libitum chow and water. The MicroCT scans were performed on pups on postnatal days 7 (P7) and P21. The volumes of the neurocranium (volume encased by the frontal, parietal, and occipital bones) and the viscerocranium (volume encased by the mandible and nasal bone), along with total skull bone volume, head size, and head circumference were evaluated using general linear models and discriminant analyses. The pups in the alcohol-treated group, when compared to the chow-fed controls (ALC vs CHOW) and the isocaloric-fed controls (ALC vs PF), showed differences in head size and circumference at P7 and P21, the total skull volume and parietal bone volume at P7, and volume of all the tested bones except nasal at P21. There was a growth trend of ALC < CHOW and ALC < PF. While covarying for gender and head size or circumference, the treatment affected the total skull and mandible at P7 (ALC > CHOW), and the total skull, parietal bone, and occipital bone at P21 (ALC < CHOW, ALC < PF). While covarying for the P7 measures, the treatment affected only the 3 neurocranial bones at P21 (ALC < CHOW, ALC < PF). Discriminant analysis sensitively selected between ALC and CHOW (AUC = 0.967), between ALC and PF (AUC = 0.995), and between PF and CHOW (AUC = 0.805). These results supported our hypothesis that craniofacial bones might be a reliable and sensitive indicator for the diagnosis of prenatal alcohol exposure. Significantly, we found that the neurocranium (upper skull) was more sensitive to alcohol than the viscerocranium (face).

Providing deep sedation and general anesthesia for patients with special needs in the dental office-based setting.

This article discusses the issues of morbidity and mortality associated with deep sedation and general anesthesia specifically in the dental office-based setting for patients with special needs (PSN). A focused review of a particular environment and patient population was challenging as it was difficult to identify articles that discuss the unique scope of this subject. During the review of the literature, no article was identified that discussed this exact topic. There were articles that discussed the delivery of general anesthesia for PSN in an outpatient setting and associated issues of morbidity and mortality. There were also articles and sources of information that discussed the delivery of general anesthesia for other patient populations in the office-based setting. In an effort to support the scope of this article, some of these articles are discussed as they pertain to the subject of this article. In addition, an analysis of the author's practice over a 4-year period is discussed in an effort to present relevant data per the scope of this article. After reviewing the literature and the author's clinical practice, it appears that the incidence of mortality for PSN in the dental office-based setting is minimal and the incidence of morbidity for this same population is limited to relatively minor events. Ultimately, it was concluded that the delivery of general anesthesia for PSN in the dental office-based setting can be considered a very safe and successful procedure.

Pathogenesis of experimental bovine spongiform encephalopathy (BSE): estimation of tissue infectivity according to incubation period.

This paper reports the results of tissue infectivity assays of bovine spongiform encephalopathy (BSE) agent in orally exposed cattle at stages during the incubation period. Estimations of the titre of infectivity in central nervous system (CNS), certain peripheral nerve ganglia and distal ileum tissue were made according to time post exposure from the relationship between incubation period and dose for RIII mice and C57bl mice using data from titrations of brain material from cases of BSE. The rate of increase of infectivity in the bovine CNS was then estimated, taking into account these tissue infectivity titres, the variability of the brain titre of clinical field cases of BSE, and the probability density of the expected number of months before clinical onset of each infected bovine. The doubling time for CNS was shown to equal 1.2 months. The titre in the thoracic dorsal root ganglia (DRG) was, on average, approximately 1 log units less than CNS, and cervical DRG approximately 0.5 log less than thoracic DRG. The pattern of increase of infectivity in the distal ileum is that of an initial increase up to 14-18 months post exposure, followed by a decrease, which is likely to be highly variable between animals. These results will be informative for future risk assessments of BSE, especially in relation to reviewing current control measures.

Improving the quality of communication in organised cervical cancer screening programmes.

OBJECTIVE: To provide health professionals involved in cervical cancer screening with an insight into the complex issues relating to communication about screening and to provide a framework for a more effective communication strategy. METHODS: This paper has been compiled by a multidisciplinary pan-European group of health professionals and cancer advocates from several European screening programmes. European surveys on screening communication, literature reviews and group discussion were used for this purpose. RESULTS: Information on cervical screening must be accessible, relevant, comprehensible, comprehensive, client-centred, phase-specific and multilevel. An effective communication strategy should consider health professionals' screening knowledge and their communication skills, consumers' health literacy skills and the communication needs of specific sub-groups in the target population. Co-operation between screening professionals, advocacy groups and journalists should be promoted. CONCLUSION: To communicate effectively and appropriately is a complex task which can be influenced by a number of factors. Screening workers need better information themselves and must take into account the needs and characteristics of the target population. PRACTICE IMPLICATIONS: This document should provide a useful tool to help screening professionals in designing and developing good quality and effective communication strategies.

Multiple Sclerosis disease distribution and potential impact of environmental air pollutants in Georgia.

Multiple Sclerosis (MS) is one of the most common diseases of the central nervous system. Although the disease has been associated with some genetic and environmental factors, it has neither clear causes nor clear temporality with respect to exposure. The purpose of this study was to explore potential relationships between MS and outdoor air pollutants in GA. This study used cross-sectional data from the member's list of the Multiple Sclerosis Society's GA chapter (MSS-GA), the US Census, and a database of county-level Toxic Release Inventory data (emissions across identified, reporting sources to outdoor air, as a surrogate indicator of potential exposure to a criteria pollutant subject to regulation or to chemical toxicants). The final study population was 9,072,576 people, including 6247 self-reported MS cases from MSS-GA. Cases were stratified by gender and transformed into county-level, self-reported prevalence rates using 2005 US Census estimates. County-level prevalence was displayed using a Geographic Information System. Linear regression was conducted to investigate potential relationships between self-reported MS prevalence rates, census data, and environmental outdoor air pollutant indicators. MS prevalence tended to be clustered within the largest metropolitan statistical area (MSA) in Georgia, around Atlanta (Fulton County). The best predictive models for the MS prevalence in GA included both per capita income and PM-10 for females, but only per capita income only for males. The clustering of prevalence of MS in the largest MSA of Georgia, after controlling for population distribution, suggested that urban attributes may be associated with MS. The results of this study further suggested a potential role of PM-10 in the etiology of MS in females, perhaps due to the influence of PM-10 on systemic immune response and inflammation. Based on this initial exploratory study, we recommend more basic and clinical exposure research to understand environmental influences on MS. In particular, outdoor air pollutants like particles, and attached chemicals and metals, which have other known adverse cardiopulmonary health outcomes and are subject to federal and state regulations, could be examined using routinely collected outdoor air monitoring station data and/or modeling.

Approaches to investigating transmission of spongiform encephalopathies in domestic animals using BSE as an example.

Bovine spongiform encephalopathy was a novel spongiform encephalopathy, in an hitherto unaffected species, that had characteristics of a point source epidemic, with an agent that could have been incorporated into a wide variety of feedstuffs and iatrogenically administered to naïve populations, and there was early evidence that it was not restricted to bovines. It was vital to establish, albeit experimentally, which other species might be affected, and whether the epidemic could be maintained by natural transmission, if the source was removed. In contrast, scrapie has been endemic throughout Great Britain for centuries, is maintained naturally (even if we don't know exactly how) and has a known host range. The principles, process and integration of evidence from different types of studies, however, are similar for both of these transmissible spongiform encephalopathies (TSE) and can be applied to any emerging or suspected spongiform encephalopathy. This review discusses the experimental approaches used to determine TSE transmissibility and infectivity and how they relate to natural disease and control measures.

Effect of exogenous reductant on growth and iron mobilization from ferrihydrite by the Pseudomonas mendocina ymp strain.

Growth of the Pseudomonas mendocina ymp strain on insoluble ferrihydrite is enhanced by exogenous reductants with concurrent increase in soluble iron concentrations. This shows that exogenous reductants play a substantial role in the overall microbial iron bioavailability. The exogenous reductants may work together with the siderophores, Fe-scavenging agents, to facilitate ferrihydrite dissolution.

Should a benzodiazepine antagonist be used in unconscious patients presenting to the emergency department?

UNLABELLED: Patients in coma with suspected drug poisoning are commonly encountered in the emergency department. Benzodiazepines are one of the most commonly used drugs in self-poisoning. Flumazenil, a benzodiazepine antagonist has been suggested as a diagnostic and treatment tool in suspected poisoning of unclear cause, but caution is required due to potential side effects. No systemic review of this literature has been done on this topic. OBJECTIVES: The aim of this study is to examine if flumazenil should be used in patients with coma from suspected drug poisoning. SEARCH STRATEGY: Randomised controlled trials were identified from the Cochrane Library, Pubmed and EMBASE. Bibliographies from included studies, known reviews and texts were searched. Content experts were contacted. SELECTION CRITERIA: Randomised controlled trials were eligible for inclusion. Studies were included if patients who presented with altered mental state from suspected drug poisoning were treated with intravenous flumazenil as compared to placebo. DATA COLLECTION AND ANALYSIS: Data were extracted and methodological quality was assessed independently by two reviewers. MAIN RESULTS: Seven randomised controlled trials were included. A total of 466 patients were involved. Flumazenil was found to reverse coma from suspected drug poisoning with a relative benefit of 4.45 (95% CI 2.65, 7.45). In terms of major side effects, there was no statistical difference between flumazenil and placebo (RR 2.86, 95% CI 0.12-69.32). However, in terms of minor side effects, flumazenil was associated with a higher incidence of anxiety (RR 2.84, 95% CI 1.28-6.30) and other side effects (RR 3.73, 95% CI 2.078-6.73). There was no difference in the incidence of vomiting (RR 4.28, 95% CI 0.95-19.35). CONCLUSION: Current evidence shows that flumazenil may be effective in the reversal of coma in patients presenting to the emergency department with coma from suspected drug poisoning.

Accuracy of popular automatic QT interval algorithms assessed by a 'gold standard' and comparison with a Novel method: computer simulation study.

BACKGROUND: Accurate measurement of the QT interval is very important from a clinical and pharmaceutical drug safety screening perspective. Expert manual measurement is both imprecise and imperfectly reproducible, yet it is used as the reference standard to assess the accuracy of current automatic computer algorithms, which thus produce reproducible but incorrect measurements of the QT interval. There is a scientific imperative to evaluate the most commonly used algorithms with an accurate and objective 'gold standard' and investigate novel automatic algorithms if the commonly used algorithms are found to be deficient. METHODS: This study uses a validated computer simulation of 8 different noise contaminated ECG waveforms (with known QT intervals of 461 and 495 ms), generated from a cell array using Luo-Rudy membrane kinetics and the Crank-Nicholson method, as a reference standard to assess the accuracy of commonly used QT measurement algorithms. Each ECG contaminated with 39 mixtures of noise at 3 levels of intensity was first filtered then subjected to three threshold methods (T1, T2, T3), two T wave slope methods (S1, S2) and a Novel method. The reproducibility and accuracy of each algorithm was compared for each ECG. RESULTS: The coefficient of variation for methods T1, T2, T3, S1, S2 and Novel were 0.36, 0.23, 1.9, 0.93, 0.92 and 0.62 respectively. For ECGs of real QT interval 461 ms the methods T1, T2, T3, S1, S2 and Novel calculated the mean QT intervals(standard deviations) to be 379.4(1.29), 368.5(0.8), 401.3(8.4), 358.9(4.8), 381.5(4.6) and 464(4.9) ms respectively. For ECGs of real QT interval 495 ms the methods T1, T2, T3, S1, S2 and Novel calculated the mean QT intervals(standard deviations) to be 396.9(1.7), 387.2(0.97), 424.9(8.7), 386.7(2.2), 396.8(2.8) and 493(0.97) ms respectively. These results showed significant differences between means at >95% confidence level. Shifting ECG baselines caused large errors of QT interval with T1 and T2 but no error with Novel. CONCLUSION: The algorithms T2, T1 and Novel gave low coefficients of variation for QT measurement. The Novel technique gave the most accurate measurement of QT interval, T3 (a differential threshold method) was the next most accurate by a large margin. The objective and accurate 'gold standard' presented in this paper may be useful to assess new QT measurement algorithms. The Novel algorithm may prove to be more accurate and reliable method to measure the QT interval.

Factors associated with triathlon-related overuse injuries.

STUDY DESIGN: Descriptive correlational investigation. OBJECTIVES: To assess the incidence of, and potential risk factors associated with, overuse injury in triathlon. BACKGROUND: The sport of triathlon is rapidly increasing in popularity with a concomitant rise in the prevalence of injuries sustained by triathletes. METHODS AND MEASURES: The training and injury patterns of 131 triathletes were surveyed over a 10-week prospective period during the triathlon competition season. A complementary retrospective 6-month analysis of training history and prior overuse injuries was conducted. RESULTS: Fifty percent of triathletes sustained an injury in the 6-month preseason at an injury exposure rate of 2.5 per 1000 training hours. Thirty-seven percent were injured during the 10-week competition season at an injury exposure rate of 4.6 per 1000 training hours. Overuse accounted for 68% of preseason and 78% of competition season injuries reported. Increased years of triathlon experience, high running mileage, history of previous injury, and inadequate warming-up and cooling-down regimes appeared to have individual associations with injury incidence. When interactions were included in a multiple logistic regression model, increasing years of triathlon experience was the most significant predictor of preseason injury risk and a previous history of injury and high preseason running mileage increased the risk of injury during the competition season. CONCLUSIONS: The results indicate that in assessing triathletes, a full training and competition history is required by the sports clinician for a comprehensive assessment of the factors that may contribute to overuse injury.

Cyanogenic potential in cassava and its influence on a generalist insect herbivore Cyrtomenus bergi (Hemiptera: Cydnidae).

The hypothesis that cyanogenic potential in cassava is a defense mechanism against arthropod pests is one of the crucial questions relevant to current efforts to reduce or eliminate cyanogenic potential (CNP) in cassava. The generalist arthropod Cyrtomenus bergi, which attacks cassava roots, was used in a bioassay relating oviposition and survival to CNP, concentration of nonglycosidic cyanogens, and linamarase (beta-glycosidase) activity in twelve selfed cassava siblings and their parental clone, which has segregated for different levels of cyanogenesis. Electron microscopic evaluation revealed an intracellular pathway of the stylet of C. bergi in the cassava root tissue to rupture cell walls. This feeding behavior causes cyanogenesis and increased linamarin content in the hemolymph of C. bergi while feeding on a cyanogenic diet. This diet resulted in a significant reduction in oviposition, especially at levels of CNP above 150 ppm (expressed as hydrogen cyanide) on fresh weight basis (or 400 ppm on dry weight basis) in cassava roots. An exponential decline in oviposition was observed with increasing levels of CNP, beginning 12 d after exposure to the cyanogenic diet. Cyanogenic potential and dry matter content showed a positive effect on survival. No relationship was found between concentrations of nonglycosidic cyanogens or linamarase activity in the cassava root and either oviposition or survival. According to our results, there is a significant difference between potentially noncyanogen and high cyanogen clones, but there may not be a significant difference between potentially noncyanogen and low cyanogen clones. Consequently, more frequent outbreaks or higher levels of damage might not be anticipated in potentially noncyanogen cassava clones than that anticipated in low cyanogenic clones. The negative effect of cyanogenesis on oviposition concurrent with a positive effect on survival of this pest is most likely the result of a physiological trade-off between survival and oviposition. The question of whether ovipositional rates could be recovered after a long-term exposure to cyanide remains unanswered.