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Backgrounds & Aims: Primary biliary cholangitis (PBC) is a chronic liver disease in which autoimmune destruction of the small intrahepatic bile ducts eventually leads to cirrhosis. Many patients have inadequate response to licensed medications, motivating the search for novel therapies. Previous genome-wide association studies (GWAS) and meta-analyses (GWMA) of PBC have identified numerous risk loci for this condition, providing insight into its aetiology. We undertook the largest GWMA of PBC to date, aiming to identify additional risk loci and prioritise candidate genes for in silico drug efficacy screening., Methods: We combined new and existing genotype data for 10,516 cases and 20,772 controls from 5 European and 2 East Asian cohorts., Results: We identified 56 genome-wide significant loci (20 novel) including 46 in European, 13 in Asian, and 41 in combined cohorts; and a 57 th genome-wide significant locus (also novel) in conditional analysis of the European cohorts. Candidate genes at newly identified loci include FCRL3, INAVA, PRDM1, IRF7, CCR6, CD226, and IL12RB1, which each play key roles in immunity. Pathway analysis reiterated the likely importance of pattern recognition receptor and TNF signalling, JAK-STAT signalling, and differentiation of T helper (T H )1 and T H 17 cells in the pathogenesis of this disease. Drug efficacy screening identified several medications predicted to be therapeutic in PBC, some of which are well-established in the treatment of other autoimmune disorders., Conclusions: This study has identified additional risk loci for PBC, provided a hierarchy of agents that could be trialled in this condition, and emphasised the value of genetic and genomic approaches to drug discovery in complex disorders., Lay Summary: Primary biliary cholangitis (PBC) is a chronic liver disease that eventually leads to cirrhosis. In this study, we analysed genetic information from 10,516 people with PBC and 20,772 healthy individuals recruited in Canada, China, Italy, Japan, the UK, or the USA. We identified several genetic regions associated with PBC. Each of these regions contains several genes. For each region, we used diverse sources of evidence to help us choose the gene most likely to be involved in causing PBC. We used these 'candidate genes' to help us identify medications that are currently used for treatment of other conditions, which might also be useful for treatment of PBC., Competing Interests: Conflicts of interest GMH has consulted and/or been a speaker for Intercept, Genfit, Cymabay, GSK, and Falk. RNS and GFM have each received research funding from Intercept Pharmaceuticals. HJC, JJF, KU, RD, YA, YH, MK, NN, S-SK, OG, YK, MN, KT, RT, YS, ZL, BDJ, EJA, AG, MC, RA, AC, MdA, AB, JH, MARF, DS, DEJ, SF, AS, VLM, KNL, CIA, MFS, PI, KAS, XM and MN report no conflicts of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2021. Published by Elsevier B.V.)

The coexistence of coronavirus disease 2019 (COVID-19) and pulmonary embolism (PE), two life-threatening illnesses, in the same patient presents a unique challenge. Guidelines have delineated how best to diagnose and manage patients with PE. However, the unique aspects of COVID-19 confound both the diagnosis and treatment of PE, and therefore require modification of established algorithms. Important considerations include adjustment of diagnostic modalities, incorporation of the prothrombotic contribution of COVID-19, management of two critical cardiorespiratory illnesses in the same patient, and protecting patients and health-care workers while providing optimal care. The benefits of a team-based approach for decision-making and coordination of care, such as that offered by pulmonary embolism response teams (PERTs), have become more evident in this crisis. The importance of careful follow-up care also is underscored for patients with these two diseases with long-term effects. This position paper from the PERT Consortium specifically addresses issues related to the diagnosis and management of PE in patients with COVID-19., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: The inflammatory biomarker interleukin-6 (IL-6) is associated with mortality in atrial fibrillation (AF)., Objective: To investigate if repeated IL-6 measurements improve the prognostication for stroke or systemic embolism, major bleeding, and mortality in anticoagulated patients with AF., Methods: IL-6 levels by ELISA were measured at study entry and at 2 months in 4830 patients in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial with 1.8 years median follow-up. In the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial, IL-6 was measured at study entry, 3, 6, and 12 months in 2559 patients with 2.0 years median follow-up. Associations between a second IL-6 measurement and outcomes, adjusted for baseline IL-6, clinical variables, and other cardiovascular biomarkers, were analyzed by Cox regression., Results: Median IL-6 levels were 2.0 ng/L (interquartile range [IQR] 1.30-3.20) and 2.10 ng/L (IQR 1.40-3.40) at the two time-points in ARISTOTLE, and, in RE-LY, 2.5 ng/L (IQR 1.6-4.3), 2.5 ng/L (IQR 1.6-4.2), 2.4 ng/L (IQR 1.6, 3.9), and 2.4 ng/L (IQR 1.5, 3.9), respectively. IL-6 was associated with mortality; hazard ratios per 50% higher IL-6 at 2 or 3 months, respectively, were 1.32 (95% confidence interval, 1.23-1.41; P < .0001) in ARISTOTLE, and 1.11 (1.01-1.22, P = .0290) in RE-LY; with improved C index from 0.74 to 0.76 in ARISTOTLE, but not in the smaller RE-LY cohort. There were no consistent associations with second IL-6 and stroke or systemic embolism, or major bleeding., Conclusions: Persistent systemic inflammatory activity, assessed by repeated IL-6 measurements, is associated with mortality independent of established clinical risk factors and other strong cardiovascular biomarkers in anticoagulated patients with AF., (© 2020 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)

Background: Takotsubo Syndrome(TTS), contrary to historical reports, is now increasingly recognised to be associated with substantial mortality and morbidity, both in the short- and long-term. Although TTS is often precipitated by a catecholamine "pulse", in-hospital hypotension is a common occurrence, increasing the risk of mortality. Furthermore, despite the transient catecholamine stimulus, there is increasing evidence that there are significant long term sequelae, including persistently impaired left ventricular(LV) systolic dysfunction, myocardial oedema with fibrosis, as well as persistent impairment of quality of life. A definitive therapeutic option to limit the extent of initial myocardial injury, and to accelerate recovery in TTS is therefore justified. However to date, there has been a lack of prospective studies in this area., Design and Rationale: NACRAM is a multi-centre, randomised, placebo-controlled trial, sequentially testing early use of intravenous N-acetylcysteine(NAC), followed by/or oral ramipril for 12 weeks. The rationale for utilising these agents is related to their effects on limiting nitrosative stress and expression of the inflammasome activator thioredoxin interacting protein(TXNIP); both processes fundamental to the pathogenesis of TTS., End Points: NACRAM is assessing resolution of myocardial oedema on cardiac magnetic resonance imaging(CMR), improvements in LV systolic function as measured by global longitudinal strain(GLS) on echocardiography, quality of life, and inflammatory markers., Discussion: To the best of our knowledge, NACRAM will be the first prospective study to help definitively evaluate a therapeutic option in acute attacks of TTS., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The AngioVac (AngioDynamics, Latham, NY) device utilizes a venovenous bypass circuit for percutaneous venous thrombectomy and has been applied in the setting of iliocaval thrombosis as well as right heart thrombus and pulmonary emboli. We describe our experience with the AngioVac device in 12 patients with a variety of indications with the goal of identifying factors correlating with successful thrombectomy., Methods: From August 2013 to June 2015, 12 patients underwent AngioVac percutaneous thrombectomy at our institution. Preoperative, intraoperative, and postoperative data were retrospectively analyzed., Results: Indications for thrombectomy included iliocaval thrombosis in 33% (4), right heart thrombus in 42% (5), and pulmonary embolus in 25% (3). We experienced a 58% complete success rate. Partial success was achieved in 17%, and no thrombus was extracted in 25%. Iliocaval and right heart thrombi were the most amenable to AngioVac thrombectomy with 100% (4/4) and 60% (3/5) complete success rates, respectively. Pulmonary embolus was the least amenable to thrombectomy with a 33% partial success rate (1/3) and 67% failure rate (2/3)., Conclusion: The AngioVac devices allow for percutaneous thrombectomy in the setting of iliocaval and right heart thrombus in patients for whom medical therapy fails or for those in whom surgical intervention is considered high risk. Pulmonary emboli are less amenable, likely due to limited steeribility of the device. Larger studies are needed to make more definitive conclusions, and newer iterations of the device will likely allow for improved outcomes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: To determine expert agreement on relative retinopathy of prematurity (ROP) disease severity and whether computer-based image analysis can model relative disease severity, and to propose consideration of a more continuous severity score for ROP., Design: We developed 2 databases of clinical images of varying disease severity (100 images and 34 images) as part of the Imaging and Informatics in ROP (i-ROP) cohort study and recruited expert physician, nonexpert physician, and nonphysician graders to classify and perform pairwise comparisons on both databases., Participants: Six participating expert ROP clinician-scientists, each with a minimum of 10 years of clinical ROP experience and 5 ROP publications, and 5 image graders (3 physicians and 2 nonphysician graders) who analyzed images that were obtained during routine ROP screening in neonatal intensive care units., Methods: Images in both databases were ranked by average disease classification (classification ranking), by pairwise comparison using the Elo rating method (comparison ranking), and by correlation with the i-ROP computer-based image analysis system., Main Outcome Measures: Interexpert agreement (weighted κ statistic) compared with the correlation coefficient (CC) between experts on pairwise comparisons and correlation between expert rankings and computer-based image analysis modeling., Results: There was variable interexpert agreement on diagnostic classification of disease (plus, preplus, or normal) among the 6 experts (mean weighted κ, 0.27; range, 0.06-0.63), but good correlation between experts on comparison ranking of disease severity (mean CC, 0.84; range, 0.74-0.93) on the set of 34 images. Comparison ranking provided a severity ranking that was in good agreement with ranking obtained by classification ranking (CC, 0.92). Comparison ranking on the larger dataset by both expert and nonexpert graders demonstrated good correlation (mean CC, 0.97; range, 0.95-0.98). The i-ROP system was able to model this continuous severity with good correlation (CC, 0.86)., Conclusions: Experts diagnose plus disease on a continuum, with poor absolute agreement on classification but good relative agreement on disease severity. These results suggest that the use of pairwise rankings and a continuous severity score, such as that provided by the i-ROP system, may improve agreement on disease severity in the future., (Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To identify patterns of interexpert discrepancy in plus disease diagnosis in retinopathy of prematurity (ROP)., Design: We developed 2 datasets of clinical images as part of the Imaging and Informatics in ROP study and determined a consensus reference standard diagnosis (RSD) for each image based on 3 independent image graders and the clinical examination results. We recruited 8 expert ROP clinicians to classify these images and compared the distribution of classifications between experts and the RSD., Participants: Eight participating experts with more than 10 years of clinical ROP experience and more than 5 peer-reviewed ROP publications who analyzed images obtained during routine ROP screening in neonatal intensive care units., Methods: Expert classification of images of plus disease in ROP., Main Outcome Measures: Interexpert agreement (weighted κ statistic) and agreement and bias on ordinal classification between experts (analysis of variance [ANOVA]) and the RSD (percent agreement)., Results: There was variable interexpert agreement on diagnostic classifications between the 8 experts and the RSD (weighted κ, 0-0.75; mean, 0.30). The RSD agreement ranged from 80% to 94% for the dataset of 100 images and from 29% to 79% for the dataset of 34 images. However, when images were ranked in order of disease severity (by average expert classification), the pattern of expert classification revealed a consistent systematic bias for each expert consistent with unique cut points for the diagnosis of plus disease and preplus disease. The 2-way ANOVA model suggested a highly significant effect of both image and user on the average score (dataset A: P < 0.05 and adjusted R 2  = 0.82; and dataset B: P < 0.05 and adjusted R 2  = 0.6615)., Conclusions: There is wide variability in the classification of plus disease by ROP experts, which occurs because experts have different cut points for the amounts of vascular abnormality required for presence of plus and preplus disease. This has important implications for research, teaching, and patient care for ROP and suggests that a continuous ROP plus disease severity score may reflect more accurately the behavior of expert ROP clinicians and may better standardize classification in the future., (Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to determine whether short-term treatment with perhexiline improves cardiac energetics, left ventricular function, and symptoms of heart failure by altering cardiac substrate utilization., Background: Perhexiline improves exercise capacity and left ventricular ejection fraction (LVEF) in patients with heart failure (HF). (31)P cardiac magnetic resonance spectroscopy can be used to quantify the myocardial phosphocreatine/adenosine triphosphate ratio. Because improvement of HF syndrome can improve cardiac energetics secondarily, we investigated the effects of short-term perhexiline therapy., Methods: Patients with systolic HF of nonischemic etiology (n = 50, 62 ± 1.8 years of age, New York Heart Association functional class II to IV, LVEF: 27.0 ± 1.44%) were randomized to receive perhexiline 200 mg or placebo for 1 month in a double-blind fashion. Clinical assessment, echocardiography, and (31)P cardiac magnetic resonance spectroscopy were performed at baseline and after 1 month. A substudy of 22 patients also underwent cross-heart blood sampling at completion of the study to quantify metabolite utilization., Results: Perhexiline therapy was associated with a 30% increase in the phosphocreatine/adenosine triphosphate ratio (from 1.16 ± 0.39 to 1.51 ± 0.51; p < 0.001) versus a 3% decrease with placebo (from 1.36 ± 0.31 to 1.34 ± 0.31; p = 0.37). Perhexiline therapy also led to an improvement in New York Heart Association functional class compared with placebo (p = 0.036). Short-term perhexiline therapy did not change LVEF. Cross-heart measures of cardiac substrate uptake and respiratory exchange ratio (which reflects the ratio of substrates used) did not differ between patients who received perhexiline versus placebo., Conclusions: Perhexiline improves cardiac energetics and symptom status with no evidence of altered cardiac substrate utilization. No change in LVEF is seen at this early stage. (Metabolic Manipulation in Chronic Heart Failure; NCT00841139)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: D-dimer is related to adverse outcomes in arterial and venous thromboembolic diseases., Objectives: To evaluate the predictive value of D-dimer level for stroke, other cardiovascular events, and bleeds, in patients with atrial fibrillation (AF) treated with oral anticoagulation with apixaban or warfarin; and to evaluate the relationship between the D-dimer levels at baseline and the treatment effect of apixaban vs. warfarin., Methods: In the ARISTOTLE trial, 18 201 patients with AF were randomized to apixaban or warfarin. D-dimer was analyzed in 14 878 patients at randomization. The cohort was separated into two groups; not receiving vitamin K antagonist (VKA) treatment and receiving VKA treatment at randomization., Results: Higher D-dimer levels were associated with increased frequencies of stroke or systemic embolism (hazard ratio [HR] [Q4 vs. Q1] 1.72, 95% confidence interval [CI] 1.14-2.59, P = 0.003), death (HR [Q4 vs. Q1] 4.04, 95% CI 3.06-5.33) and major bleeding (HR [Q4 vs. Q1] 2.47, 95% CI 1.77-3.45, P < 0.0001) in the no-VKA group. Similar results were obtained in the on-VKA group. Adding D-dimer level to the CHADS2 score improved the C-index from 0.646 to 0.655 for stroke or systemic embolism, and from 0.598 to 0.662 for death, in the no-VKA group. D-dimer level improved the HAS-BLED score for prediction of major bleeds, with an increase in the C-index from 0.610 to 0.641. There were no significant interactions between efficacy and safety of study treatment and D-dimer level., Conclusion: In anticoagulated patients with AF, the level of D-dimer is related to the risk of stroke, death, and bleeding, and adds to the predictive value of clinical risk scores. The benefits of apixaban were consistent, regardless of the baseline D-dimer level., (© 2014 International Society on Thrombosis and Haemostasis.)

Purpose: The present study investigated whether the prevalence of mood and anxiety disorders has increased over time among current smokers and whether these trends differ by gender and in comparison with nonsmokers., Methods: Data were drawn from the National Comorbidity Survey (1990) and the National Comorbidity Survey-Replication (2001), representative samples of the US adult population. Binomial regression analyses were used to determine differences between mood and anxiety disorders among current smokers in 1990 and 2001 and whether these differed by gender and in comparison with those who were former or never current smokers., Results: Any anxiety disorder, panic attacks, panic disorder, social anxiety disorder and dysthymia were all significantly more common among current smokers in 2001 compared with 1990 and except for social anxiety disorder these increases were significantly greater than any trend found in non-smokers. Increases in panic attacks, social anxiety disorder, and dysthymia were more pronounced in female than in male smokers. Major depressive disorder and generalized anxiety disorder were not found to increase over time among smokers., Conclusions: The prevalence of several anxiety disorders and dysthymia among current smokers appears to have increased from 1990 to 2001. Future studies are needed to determine whether these trends have continued. If so, interventions aimed at moving the prevalence lower may have limited success if treatment of mental health problems such as anxiety disorders and certain mood disorders are not considered in the development and dissemination of tobacco control programs., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Aim: Takotsubo cardiomyopathy (TTC) is a disorder of myocardial inflammation induced by high catecholamine levels and is associated with acute complications. In the long-term TTC is associated with a risk of single or multiple recurrences, but risk of such occurrences is not clear. We performed a systematic review and meta-analysis to identify and consolidate the evidence on the incidence and clinical correlates of cases of TTC recurrence., Methods: A comprehensive search of four major databases (EMBASE, OVID Medline, PubMed and Google Scholar) was performed from their inception to first week of Jan 2014. We included original research studies, recruiting ≥ 5 participants, with ≥ 3 months follow-up, published in English language that reported data on recurrence in patients with TTC., Results: Out of 298 studies searched, 31 cohorts (1664 TTC patients) were included in the analyses. Out of 74 cases of recurrence, with a mean follow-up of 24.5 months (95% CI, 19.3 to 33 months), extensive recurrence data were available for 23 cases. Cumulative incidence of recurrence was approximately 5% at 6 years. Annual rate of recurrence was approximately 1.5%. Furthermore, 14% of cases had recurrent chest pain and 11% reported dyspnea without definite evidence of recurrent TTC. Discharge medications at index admission included β-adrenoceptor antagonists (BB) in 66.8% and ACE inhibitors (ACEi) and ARB in 67.4%. Recurrence rate was independent of clinic utilization of BB prescription, but inversely correlated (r=-0.45, p=0.016) with ACEi/ARB prescription. Patients with severe TTC at index admission were noted to have more recurrences., Conclusions: (1) TTC is associated with only 1-2% annual recurrence rate but substantially greater frequency of ongoing symptoms. (2) ACEi/ARB rather than BB may reduce risk of recurrence., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Impaired platelet responsiveness to nitric oxide (NO resistance) is a common characteristic of many cardiovascular disease states and represents an independent risk factor for cardiac events and mortality. NO resistance reflects both scavenging of NO by superoxide (O2(-)), and impairment of the NO receptor, soluble guanylate cyclase (sGC). There is thus an urgent need for circumvention of NO resistance in order to improve clinical outcomes. Nitroxyl (HNO), like NO, produces vasodilator and anti-aggregatory effects, largely via sGC activation, but is not inactivated by O2(-). We tested the hypothesis that HNO circumvents NO resistance in human platelets. In 57 subjects with or without ischemic heart disease, platelet responses to the HNO donor isopropylamine NONOate (IPA/NO) and the NO donor sodium nitroprusside (SNP) were compared. While SNP (10μM) induced 29±3% (p<0.001) inhibition of platelet aggregation, IPA/NO (10μM) caused 75±4% inhibition (p<0.001). In NO-resistant subjects (n=28), the IPA/NO:SNP response ratio was markedly increased (p<0.01), consistent with partial circumvention of NO resistance. Similarly, cGMP accumulation in platelets was greater (p<0.001) with IPA/NO than with SNP stimulation. The NO scavenger carboxy-PTIO (CPTIO, 200μM) inhibited SNP and IPA/NO responses by 92±7% and 17±4% respectively (p<0.001 for differential inhibition), suggesting that effects of IPA/NO are only partially NO-mediated. ODQ (10μM) inhibited IPA/NO responses by 36±8% (p<0.001), consistent with a contribution of sGC/haem to IPA/NO inhibition of aggregation. There was no significant relationship between whole blood ROS content and IPA/NO responses. Thus the HNO donor IPA/NO substantially circumvents platelet NO resistance while acting, at least partially, as a haem-mediated sGC activator., (Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.)

Background: The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial showed that apixaban is better than warfarin at prevention of stroke or systemic embolism, causes less bleeding, and results in lower mortality. We assessed in this trial's participants how results differed according to patients' CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores, used to predict the risk of stroke and bleeding., Methods: ARISTOTLE was a double-blind, randomised trial that enrolled 18,201 patients with atrial fibrillation in 39 countries. Patients were randomly assigned apixaban 5 mg twice daily (n=9120) or warfarin (target international normalised ratio 2·0-3·0; n=9081). The primary endpoint was stroke or systemic embolism. The primary safety outcome was major bleeding. We calculated CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores of patients at randomisation. Efficacy analyses were by intention to treat, and safety analyses were of the population who received the study drug. ARISTOTLE is registered with ClinicalTrials.gov, number NCT00412984., Findings: Apixaban significantly reduced stroke or systemic embolism with no evidence of a differential effect by risk of stroke (CHADS(2) 1, 2, or ≥3, p for interaction=0·4457; or CHA(2)DS(2)VASc 1, 2, or ≥3, p for interaction=0·1210) or bleeding (HAS-BLED 0-1, 2, or ≥3, p for interaction=0·9422). Patients who received apixaban had lower rates of major bleeding than did those who received warfarin, with no difference across all score categories (CHADS(2), p for interaction=0·4018; CHA(2)DS(2)VASc, p for interaction=0·2059; HAS-BLED, p for interaction=0·7127). The relative risk reduction in intracranial bleeding tended to be greater in patients with HAS-BLED scores of 3 or higher (hazard ratio [HR] 0·22, 95% CI 0·10-0·48) than in those with HAS-BLED scores of 0-1 (HR 0·66, 0·39-1·12; p for interaction=0·0604)., Interpretation: Because apixaban has benefits over warfarin that are consistent across patient risk of stroke and bleeding as assessed by the CHADS2, CHA2DS2VASc, and HAS-BLED scores, these scores might be less relevant when used to tailor apixaban treatment to individual patients than they are for warfarin. Further improvement in risk stratification for both stroke and bleeding is needed, particularly for patients with atrial fibrillation at low risk for these events., Funding: Bristol-Myers Squibb and Pfizer., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Polycystic ovary syndrome (PCOS) is associated with incremental risk of atherosclerosis and possibly of cardiovascular events. Insulin resistance (IR) occurs frequently in PCOS subjects, which might be one of the mechanisms involved in engendering such risk. We sought to evaluate whether the impact of other factors potentially associated both with PCOS and with IR might differentially modulate degree of IR in women with and without PCOS., Methods and Results: We measured body mass index (BMI), hs-CRP, plasma concentrations of asymmetric dimethylarginine (ADMA), vitamin D (25(OH)D3) levels and platelet responsiveness to nitric oxide donor sodium nitroprusside (NO responsiveness) in 47 young women (n=27 with PCOS and n=20 weight-matched controls) without metabolic syndrome, hypertension or overt cardiovascular disease. We performed univariate and multivariate regression analyses to establish correlates of the quantitative insulin-sensitivity check index (QUICKI), as a marker of IR. On univariate analysis, plasma 25(OH)D3 levels and low NO responsiveness tended to be direct correlates with QUICKI in the entire subject group. BMI, hs-CRP, and ADMA levels were significant inverse correlates of QUICKI in PCOS subjects, but not in subjects without PCOS. On multivariate analysis, NO responsiveness, and 25(OH)D3 levels, but not PCOS per se were significant correlates of QUICKI., Conclusions: In the entire cohort of young women, low NO responsiveness and vitamin D deficiency are associated with low QUICKI, while elevated ADMA, inflammatory activation and obesity are selectively associated with low QUICKI in PCOS subjects; this may contribute to the increased cardiovascular risk associated with this syndrome., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Nitric oxide (NO) is a modulator of left ventricular hypertrophy (LVH) and myocardial relaxation. The impact of NO availability on development of LVH has never been demonstrated in humans. We tested the hypotheses that elevation of asymmetric dimethylarginine (ADMA) concentrations (biochemical marker of decreased NO generation), and impairment of vascular responsiveness to NO donor GTN, would each predict the presence of LVH and associated LV diastolic dysfunction in a normal aging population., Methods and Results: In 74 subjects aged 68±6 years, LV volumes and mass indexed to height(2.7) (LVMI) were calculated from cardiac MRI. Despite the absence of clinically-defined LVH, there was a relationship (r=0.29; p=0.01) between systolic BP and LVMI. Both elevation of ADMA levels to the highest quartile or impairment of GTN responsiveness (determined by applanation tonometry) to the lowest quartile were determinants of LVMI independent of systolic BP (p=0.01 and p=0.03, respectively). Filling pressure (E/E' ratio from echocardiography) was increased in patients with impaired vascular NO responsiveness (p<0.05) irrespective of LVMI. ADMA remained a significant determinant of LVMI on multivariate analysis., Conclusions: These data imply that NO bioavailability within the myocardium modulates earliest stages of LVH development and facilitates development of diastolic dysfunction at a given LV mass., (Copyright © 2011. Published by Elsevier Inc.)

Background: Prasugrel is a newly marketed antiplatelet drug with improved cardiac outcomes as compared with clopidogrel for acute coronary syndromes involving percutaneous coronary intervention (PCI). Analysis of a subset of the TRITON-TIMI 38 trial demonstrated that cytochrome P450 2C19 (CYP2C19) reduced-function genotypes are associated with differential clinical responses to clopidogrel, but not prasugrel. Whether the CYP2C19 genotype has the potential to influence clinical choice of these drugs prior to PCI for individuals with unstable angina or non-ST segment elevation myocardial infarction is currently uncertain., Methods and Results: An exploratory, secondary analysis was undertaken to estimate the clinical benefit of prasugrel over clopidogrel in subgroups defined by CYP2C19 genotype, by integrating the published results of the genetic substudy and the overall TRITON-TIMI 38 trial. Individuals with a CYP2C19 reduced-metabolizer genotype were estimated to have a substantial reduction in the risk of the composite primary outcome (cardiovascular death, myocardial infarction, or stroke) with prasugrel as compared with clopidogrel [relative risk (RR) 0.57; 95% confidence interval (CI) 0.39-0.83]. For CYP2C19 extensive metabolizers (∼70% of the population), however, the composite outcome risks with prasugrel and clopidogrel were not substantially different (RR 0.98; 95% CI 0.80-1.20)., Conclusions: Integration of the TRITON-TIMI 38 data suggests that the CYP2C19 genotype can discriminate between individuals who receive extensive benefit from using prasugrel instead of clopidogrel, and individuals with comparable clinical outcomes with prasugrel and clopidorel. Thus, CYP2C19 genotyping has the potential to guide the choice of antiplatelet therapy, and further research is warranted to validate this estimate., (© 2010 International Society on Thrombosis and Haemostasis.)

Background: Perhexiline improves functional capacity in heart failure, but the mechanisms are undefined. We sought its effects on myocardial deformation in patients with viable myocardium., Methods: Thirty-six medically-treated patients, stable at least 6 months post-infarction with LV dysfunction and myocardial viability shown by dobutamine echo (DbE) were randomised to receive perhexiline or matching placebo for 1 year. Cardiopulmonary exercise testing and DbE were performed at baseline and follow-up. Peak-systolic strain (S) and strain rate (SR) were measured offline in 111 dysfunctional segments in the placebo and 88 in the treatment group at rest, low-dose (LDD) and peak-dose dobutamine (PDD)., Results: The serum perhexiline level was 0.27+/-0.7 microg/l. There was no difference in the wall motion response to dobutamine at baseline and follow-up. Resting strain and SR were similar in the two groups at baseline and follow-up. However, SR at LDD and PDD increased in the placebo group and worsened during the same period in the perhexiline group. Patients on perhexiline and placebo had a similar rate-pressure product and exercise duration at baseline (7.9+/-2.7 vs 8.7+/-3.3 min, p=NS) and follow-up (9.6+/-4.6 vs 10.1+/-3.03 min, p=NS)., Conclusion: Perhexiline does not improve the deformation of abnormal myocardial segments in patients with ischaemic LV dysfunction., (Copyright 2009. Published by Elsevier Ireland Ltd.)

Purpose: Data are unavailable for rational selection of pulse sequences to assess postinfarction myocardial viability in rodents at high field strength. We implemented a widely used clinical inversion recovery (IR) sequence at 4.7T and compared the results to a heavily T1-weighted cine FLASH sequence (T1-CF) for assessment of infarction size., Materials and Methods: Eleven infarcted rats were examined within 24 h of infarction after injection of Gadophrin-3 contrast agent. Images were acquired using both pulse sequences and a standard cine (SC) sequence. Estimates of infarct size were compared to TTC. Global LV function was compared between the T1-CF and SC sequences., Results: SNR, relative SNR, and CNR for the infarcted and normal myocardium were significantly greater for the IR sequence. Infarction size was overestimated by both sequences, but correlated highly and showed very close agreement with TTC. Global function revealed no significant differences between T1-CF and SC., Conclusion: Both IR and T1-CF produced reliable results for assessment of infarction size at 4.7T. While the IR sequence delivers better overall SNR and CNR, the T1-CF allows concomitant assessment of global cardiac function with a much shorter acquisition time.

Industrial microbial count records usually form an irregular fluctuating time series. If the series is truly random or weakly autocorrelated, the fluctuations can be considered as the outcome of the interplay of numerous factors that promote or inhibit growth. These factors usually balance each other, although not perfectly, hence, the random fluctuations. If conditions are unchanged, then at least in principle the probability that they will produce a coherent effect, i.e., an unusually high (or low) count of a given magnitude, can be calculated from the count distribution. This theory was tested with miscellaneous industrial records (e.g., standard plate count, coliforms, yeasts) of various food products, including a dairy-based snack, frozen foods, and raw milk, using the normal, log normal, Laplace, log Laplace, Weibull, extreme value, beta, and log beta distribution functions. Comparing predicted frequencies of counts exceeding selected levels with those actually observed in fresh data assessed their efficacy. No single distribution was found to be inherently or consistently superior. It is, therefore, suggested that, when the probability of an excessive count is estimated, several distribution functions be used simultaneously and a conservative value be used as the measure of the risk.

Background: Alterations in glucose metabolism during early fasting may be an important trigger of the hormonal and metabolic responses to fasting., Objective: The purpose of this study was to determine whether glucose metabolism in response to brief starvation differs in lean and abdominally obese women., Design: We evaluated whole-body glucose metabolism by use of stable-isotope tracer methods and glucose uptake in subcutaneous abdominal adipose tissue by use of arteriovenous balance in 7 lean [58 +/- 2 kg; body mass index (BMI; in kg/m(2)): 21 +/- 5] and 6 abdominally obese (96 +/- 2 kg; BMI: 36 +/- 1) women after 14 and 22 h of fasting., Results: Between 14 and 22 h of fasting, whole-body glucose production and disposal declined in both groups (P < 0.05), but the reduction was 50% greater in lean than in obese women (P < 0.05). The decline in glucose uptake at 22 h of fasting was also lower in obese (0.11 +/- 0.04 micromol*100 g(-1) x min(-1)) than in lean (0.26 +/- 0.03 micromol x 100 g(-1) x min(-1)) women (P < 0.05). Decreases in plasma insulin and leptin concentrations between 14 and 22 h of fasting were also lower in obese than in lean women (insulin: 20 +/- 3% and 32 +/- 5%; leptin: 18 +/- 3% and 37 +/- 6%; both P < 0.05)., Conclusions: The normal decline in glucose production and uptake that occurs during early fasting is blunted in women with abdominal obesity. These alterations in glucose metabolism are associated with a blunted decline in circulating concentrations of both insulin and leptin, which may explain some of the differences in the metabolic response to fasting observed between lean and abdominally obese persons.

Carotid angioplasty and stenting (CAS) is being promoted for patients with carotid artery stenosis who have received neck irradiation. We reviewed our experience with carotid endarterectomy (CEA) following neck irradiation to determine if indeed postoperative and long-term problems were an issue in these patients. Over the past 13 years, 10 patients with a history of neck irradiation underwent 11 procedures. The average time interval between radiation treatment and surgery was 14 years (range 1-44). All carotid arteries were repaired with a standard endarterectomy, eight of which were patched. Three patients had undergone a radical neck dissection on the side ipsilateral to the carotid lesion. They received a pectoral myocutaneous flap (PMF) to protect the carotid artery and optimize wound healing. The lack of perioperative complications and of morbidity indicate that carotid reconstruction for patients with previous neck irradiation is safe and durable. Until long-term favorable results with CAS are available for these patients, operative intervention should remain the standard treatment.

Endogenous triacylglycerols represent an important source of fuel for endurance exercise. Triacylglycerol oxidation increases progressively during exercise; the specific rate is determined by energy requirements of working muscles, fatty acid delivery to muscle mitochondria, and the oxidation of other substrates. The catecholamine response to exercise increases lipolysis of adipose tissue triacylglycerols and, presumably, intramuscular triacylglycerols. In addition, increases in adipose tissue and muscle blood flow decrease fatty acid reesterification and facilitate the delivery of released fatty acids to skeletal muscle. Alterations in fatty acid mobilization and the relative use of adipose and intramuscular triacylglycerols during exercise depend, in large part, on degree of fitness and exercise intensity. Compared with untrained persons exercising at the same absolute intensity, persons who have undergone endurance training have greater fat oxidation during exercise without increased lipolysis. Available evidence suggests that the training-induced increase in fat oxidation is due primarily to increased oxidation of non-plasma-derived fatty acids, perhaps from intramuscular triacylglycerol stores. Fat oxidation is lower in high-intensity exercise than in moderate-intensity exercise, in part because of decreased fatty acid delivery to exercising muscles. Parenteral lipid supplementation during high-intensity exercise increases fat oxidation, but the effect of ingesting long-chain or medium-chain triacylglycerols on substrate metabolism during exercise is less clear. This review discusses the relation between fatty acid mobilization and oxidation during exercise and the effect of endurance training, exercise intensity, and lipid supplementation on these responses.

Objective: To examine mothers' postpartum perceptions of stress and satisfaction., Design: Methodologic triangulation with quantitative and qualitative data in a nonexperimental design., Participants and Setting: A convenience sample of 95 women was obtained during normally scheduled postpartum appointments at a health maintenance organization., Main Outcome Measures: The self-administered questionnaire included the Mothers' Information Tool (MIT), What Being the Parent of a Baby Is Like (WPL-R), and the Brief Symptom Inventory (BSI). Open-ended MIT items revealed mothers' perceptions of stress and satisfaction. The WPL-R provided maternal satisfaction scores, and the BSI yielded Global Stress Index scores., Results: Content analysis identified the following categories: Roles, Tasks, Resources, and Relationships. Subcategories identified as areas of stress were Work/School, Sleep/Rest, Adjustment/Own Needs, Health/Body Image, Organization of Life, Child Care, Day Care, Housework, Future Challenges, Finances, Housing, Time, Partner, and Family. Subcategories identified as areas of satisfaction were Participating in Relationships, Sharing the Future, Being Proud to Be a Mother, Enjoying a Healthy Baby, and Caring for a Child. Levels of stress and satisfaction of mothers who scored high and low on quantitative measures were compared., Conclusion: The outcomes contribute to the knowledge concerning postpartum women's perceptions of the mothering experience and suggest approaches to nursing assessment and intervention to prevent postpartum adjustment difficulties.

Background: Hospital admissions among patients with congestive heart failure (CHF) are a major contributor to health-care costs. Previous investigations suggest that the therapeutic efficacy of pharmacotherapy in CHF may be improved by strategies incorporating home visits to identify and address factors precipitating deterioration and resultant readmission., Methods: Chronic CHF patients discharged home after acute hospital admission were randomly assigned usual care (n=100) or a multidisciplinary, home-based intervention (n=100), consisting of a home visit by a cardiac nurse 7-14 days after discharge. The primary endpoint of the study was frequency of unplanned readmission plus out-of-hospital death within 6 months., Findings: During 6 months' follow-up there were 129 primary endpoint events in the usual-care group and 77 in the intervention group (p=0.02). More intervention-group than usual-care patients remained event-free (38 vs 51; p=0.04). Overall, there were fewer unplanned readmissions (68 vs 118; p=0.03) and associated days in hospital (460 vs 1173; p=0.02) among intervention-group patients. Hospital-based costs were Australian $490,300 for the intervention group and A$922,600 for the usual-care group (p=0.16); the mean cost of the intervention was A$350 per patient, and other community-based costs were similar for both groups., Interpretation: A home-based intervention has the potential to decrease the rate of unplanned readmissions and associated health-care costs, prolong event-free and total survival, and improve quality of life among patients with chronic CHF.

Long-Evans and Sprague-Dawley rats show differential behavioral responses to cocaethylene, a metabolite derived from the simultaneous ingestion of ethanol and cocaine. Such differences may also be manifested when these outbred strains are exposed to ethanol and cocaine. To test this hypothesis, both strains were fed an ethanol-diet (8.7% v/v) in conjunction with cocaine (15 mg/kg) injections for 15 days. The following parameters were evaluated: (a) ethanol consumption, (b) cocaine-induced behavioral activity, (c) blood ethanol levels, (d) blood, liver, or brain cocaine and cocaethylene levels, and (e) liver catalase and esterase activity. We found that Long-Evans rats drank significantly more of the ethanol diet relative to the Sprague-Dawley line during the first few days of the test session. This rat phenotype also differed significantly from the Sprague-Dawley line in terms of behavioral activity after cocaine administration. Blood ethanol levels did not differ between strains. Similarly, we failed to detect strain-dependent differences in blood, liver, or brain cocaine levels as measured by gas chromatography/mass spectrometry. Cocaethylene levels, however, were higher in blood and brain of Long-Evans relative to Sprague-Dawley cohorts. Although the ethanol-cocaine regimen produced a marked suppression of catalase and esterase activity compared with control-fed rats, this suppression was roughly equivalent in both rat phenotypes. These data are discussed in the context of genotypic background and vulnerability to polysubstance abuse.

This study reports the measurements of fluoxetine in discrete brain regions, blood, liver and hair of male rats injected with 10 mg/kg fluoxetine HCl for 15 consecutive days. Concentrations of the antidepressant were obtained by gas chromatography-mass spectrometry (GC-MS) methodology. In brain, fluoxetine levels were unevenly distributed, with the raphé nucleus containing the highest amounts relative to the hypothalamus or striatum. Fluoxetine was also measured in blood and liver roughly paralleling those ratios described in previous rodent studies. Of potential interest, fluoxetine was found to accumulate in rat hair after chronic treatment. Detection of fluoxetine in hair by GC-MS could be used as a marker for probative analyses.

We have recently reported the time course of acute myocardial drug uptake and simultaneous pharmacodynamic effects for metoprolol (4 mg; n = 12) and sotalol (20 mg; n = 10) in patients with ischemic heart disease. The acute pharmacodynamic effects of the two drugs included reductions in both spontaneous heart rate and the contractile index peak positive rate of left ventricular pressure rise and prolongation of the electrocardiographic PR interval, all of which exhibited an equilibration delay compared with myocardial drug content. The objective of the current study was to analyze the relationship between myocardial drug content and effect for both metoprolol and sotalol using an effect compartment model, to examine the potential for the two drugs to share a common subsite of action in the myocardium. The time course of myocardial drug content was best described by a one-compartment model for metoprolol and a two-compartment model for sotalol. A linear pharmacodynamic model, relating the amount of drug at the effect-site (Ae) with each of the three effects, was used in the effect compartment modeling. The slope of each of these effects as a function of Ae was considerably flatter for sotalol than for metoprolol, reflecting the relative beta-adrenoceptor antagonistic potencies of the two drugs. The exit rate constant from the effect compartment (K(eo)) did not differ significantly from each other or from the exit rate constant from the "peripheral" compartment (K21) for sotalol. The results suggest that the effect compartment within the myocardium for both drugs may correspond to a "peripheral" compartment, even though a "peripheral" pharmacokinetic compartment for myocardial metoprolol content was not apparent. Thus, the effect compartment for many cardioactive drugs may correspond to a pharmacokinetically "peripheral" compartment, irrespective of localization of effect to a small (e.g. sinoatrial node) or large (e.g. ventricular myocardium) region of the heart.

Background: In patients with poor left ventricular function, the determinants of outcome after revascularization are unknown., Methods: We studied prospectively 57 patients with stable coronary artery disease and poor left ventricular function (left ventricular ejection fraction, 0.28 +/- 0.04) who underwent coronary artery bypass grafting. Clinical variables were assessed as predictors of outcome in all patients, and preoperative stress thallium-201 scintigraphic data were analysed in 37 patients., Results: The operative mortality was 1.7%. At 12 months after operation, 46 of the 49 survivors were angina-free and 35 had fewer heart failure symptoms, but postoperative left ventricular ejection fraction (0.30 +/- 0.09) did not change significantly. Eighteen survivors had left ventricular ejection fraction improved by 0.05 or more (0.30 +/- 0.03 preoperatively, 0.40 +/- 0.05 postoperatively; p = 0.0001). The adjusted odds ratio of large reversible thallium-201 defects in predicting such outcome was 15 (95% confidence interval, 1.6 to 140), whereas other clinical variables had no predictive value. The transplantation-free 5-year survival was 73%., Conclusions: In patients with poor left ventricular function, surgical revascularization can be performed safely, with good symptomatic relief and long-term survival. One-year survival and improvement in left ventricular function is better in patients with large reversible defects on preoperative stress thallium-201 scintigraphy.

During a routine dental examination, a general dentist noticed facial asymmetry in a 42-year-old man. Dental radiography suggested a pathological condition in the sinuses. The dentist referred the patient to a head and neck surgeon for further examination. Computed tomography demonstrated ectopic molars in the maxillary sinuses blocking drainage of the sinuses.

We examined the relationship between streptokinase infusion, intensity of myocardial injury and systemic hypotension in patients receiving streptokinase for treatment of evolving acute myocardial infarction. Twenty consecutive patients treated with streptokinase for evolving acute myocardial infarction received continuous blood pressure and S-T segment monitoring of the 12 lead electrocardiogram (ECG) for at least 5 h, commencing prior to commencement of the streptokinase infusion. Aggravation of injury, manifested both by episodic increases in S-T segment elevation on the electrocardiogram (ECG) (P < 0.001), and in mean S-T segment elevation (P < 0.05) occurred within the first 20 min after initiation of streptokinase infusion. Hypotension also occurred transiently in most patients, with a mean minimum systolic blood pressure of 92 +/- 22 (S.D.) mmHg occurring 16 +/- 5 min after commencement of streptokinase. There was no correlation between the extent of aggravation of injury and that of hypotension. All patients showed ECG evidence of reperfusion, with a reduction of S-T elevation in the reference lead to 50% of maximal value, after a median of 62 min (range 9-174 min). It is concluded that streptokinase aggravates injury prior to reperfusion, although probably not via the induction of hypotension: It is possible that this effect contributes to the 'early hazard' of thrombolytic therapy.

To determine the potential utility of the detection of silent myocardial ischemia after acute myocardial infarction for clinical decision making, we investigated the hypothesis that the occurrence of silent myocardial ischemia on ambulatory electrocardiographic (EGG) monitoring after acute myocardial infarction is independently predictive of adverse outcome in patients in whom conventional clinical and investigative parameters indicate favourable prognosis on medical therapy. Among 465 consecutive patients admitted to our Coronary Care Unit with acute myocardial infarction, 42 patients (39% of those eligible) were randomly selected for study. Twenty-four hour ambulatory ECG monitoring was carried out 13 +/- 10 (standard deviation) days post-acute myocardial infarction. Ninety-eight percent of patients were receiving prophylactic anti-ischemic medications and 81% on aspirin. Silent myocardial ischemia was detected in 14%. During the follow-up period of 16 +/- 3 months, acute ischemic events occurred in 33% of those with silent myocardial ischemia and 19% of those without previous silent myocardial ischemia (P = 0.59). The sensitivity of the test for prediction of future acute ischemic events was 22% (95% confidence interval: 3-60%), specificity 87% (95% confidence interval: 72-97%), positive predictive value 33% (95% confidence interval: 4-78%) and negative predictive value 81% (95% confidence interval: 64-92%). Therefore the detection of ambulatory silent myocardial ischemia after acute myocardial infarction is not of sufficient incremental value as a predictor of the occurrence of adverse cardiac events to justify its routine clinical use in this subgroup of patients.

Recent advances in balloon catheter technology allow percutaneous transluminal angioplasty (PTA) of small arteries such as the tibial arteries. PTA can thus be used to treat lower limb ischemia in diabetic patients whose arterial occlusive disease is often localized to the tibial arteries. This series included 14 consecutive diabetic patients who underwent tibial PTA for treatment of limb-threatening ischemia from 1986 to 1992. PTA was selected over conventional bypass procedures because of a lack of autogenous conduit or because of an unacceptably high surgical risk. Limb loss was imminent without prompt improvement in foot perfusion in all patients. Mean follow-up of 17 months demonstrated long-term limb salvage in 10/13 (77%) and "late" cardiac-related death in 3/13 (23%). This series demonstrates that although conventional arterial bypass should routinely supersede angioplasty procedures, tibial PTA offers the opportunity for limb salvage in diabetic patients with inadequate autogenous conduit for distal tibial bypass and may serve as an option for those who are considered too high risk for conventional bypass. Morbidity and mortality rates of tibial PTA parallel those of major amputation in this population with the obvious benefit of achieving limb salvage in carefully selected diabetic patients.

After a 12-h fast six different meals (potatoes, rice, sucrose solution, potatoes+margarine, rice+margarine, and a confectionery bar), each containing 0.7 g carbohydrate/kg body wt, were consumed 30 min before exercise (n = 9). During the 30 min immediately after ingestion, the glycemic and insulinemic responses to the meals distinguished these foods into two groups: 1) high glycemic (ie, potatoes, sucrose, confectionery bar) and 2) moderate glycemic (ie, rice, potatoes+margarine, rice+margarine). After 20 min of moderate-intensity exercise, plasma glucose declined in all carbohydrate trials to values of 3.4 +/- 0.1 mmol/L, which were significantly (P < 0.05) lower than values after subjects fasted (4.2 +/- 0.2 mmol/L). Therefore, the glycemic and insulinemic responses to these meals were independent of their carbohydrate classification of simple or complex and the addition of fat reduced the glycemic and insulinemic responses. However, despite these different responses before exercise, all of the meals caused plasma glucose to decline to equally low concentrations early in exercise.

Infectious complications of the foot are a major cause of morbidity and mortality in diabetic patients. This prospective study evaluated the ability of MRI to adequately direct the medical and surgical management of 41 diabetic patients with acute foot infections. Forty-seven MRI scans of the foot in question were performed and classified as consistent with osteomyelitis, abscess, cellulitis or diffuse soft tissue infection, or any combination of these. Twenty-seven scans were negative or showed ill-defined soft tissue infection, or superficial cellulitis. Nineteen of these infections were treated nonoperatively and 17 resolved without surgical intervention. MRI was unsuccessful in directing management in one patient in whom an abscess spontaneously drained but was not seen on an MRI scan 4 days earlier. Eight scans revealed focal osteomyelitis and all eight of these patients were successfully managed with one operation. MRI showed a focal abscess in 12 patients, and adequate drainage was achieved without excessive disruption of uninvolved tissue planes in 11 of these patients. The remaining patient required a major amputation from the outset. Based on clinical outcome during the acute hospitalization period, operative findings, and/or pathologic confirmation, the positive predictive value of MRI in defining infectious pathology in the foot was 100% in this series of 20 positive scans. The negative predictive value of MRI was 96%. On the basis of this experience, we conclude that MRI is a diagnostic modality particularly well suited to evaluate acute diabetic foot infections and reliably aids in the management of acute infection to avoid exploration and debridement of uninvolved tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to utilize 19F nuclear magnetic resonance (NMR) to probe the solution structure of Escherichia coli tRNAVal labeled by incorporation of 5-fluorouracil, we have assigned its 19F spectrum. We describe here assignments made by examining the spectra of a series of tRNAVal mutants with nucleotide substitutions for individual 5-fluorouracil residues. The result of base replacements on the structure and function of the tRNA are also characterized. Mutants were prepared by oligonucleotide-directed mutagenesis of a cloned tRNAVal gene, and the tRNAs transcribed in vitro by bacteriophage T7 RNA polymerase. By identifying the missing peak in the 19F NMR spectrum of each tRNA variant we were able to assign resonances from fluorouracil residues in loop and stem regions of the tRNA. As a result of the assignment of FU33, FU34 and FU29, temperature-dependent spectral shifts could be attributed to changes in anticodon loop and stem conformation. Observation of a magnesium ion-dependent splitting of the resonance assigned to FU64 suggested that the T-arm of tRNAVal can exist in two conformations in slow exchange on the NMR time scale. Replacement of most 5-fluorouracil residues in loops and stems had little effect on the structure of tRNAVal; few shifts in the 19F NMR spectrum of the mutant tRNAs were noted. However, replacing the FU29.A41 base-pair in the anticodon stem with C29.G41 induced conformational changes in the anticodon loop as well as in the P-10 loop. Effects of nucleotide substitution on aminoacylation were determined by comparing the Vmax and Km values of tRNAVal mutants with those of the wild-type tRNA. Nucleotide substitution at the 3' end of the anticodon (position 36) reduced the aminoacylation efficiency (Vmax/Km) of tRNAVal by three orders of magnitude. Base replacement at the 5' end of the anticodon (position 34) had only a small negative effect on the aminoacylation efficiency. Substitution of the FU29.A41 base-pair increased the Km value 20-fold, while Vmax remained almost unchanged. The FU4.A69 base-pair in the acceptor stem, could readily be replaced with little effect on the aminoacylation efficiency of E. coli tRNAVal, indicating that this base-pair is not an identity element of the tRNA, as suggested by others.

To complete assignment of the 19F nuclear magnetic resonance (NMR) spectrum of 5-fluorouracil-substituted Escherichia coli tRNA(Val), resonances from 5-fluorouracil residues involved in tertiary interactions have been identified. Because these assignments could not be made directly by the base-replacement method used to assign 5-fluorouracil residues in loop and stem regions of the tRNA, alternative assignment strategies were employed. FU54 and FU55 were identified by 19F homonuclear Overhauser experiments and were then assigned by comparison of their 19F NMR spectra with those of 5-fluorouracil-labeled yeast tRNA(Phe) mutants having FU54 replaced by adenine and FU55 replaced by cytosine. FU8 and FU12, were assigned from the 19F NMR spectrum of the tRNA(Val) mutant in which the base triple G9-C23-G12 substituted for the wild-type A9-A23-FU12. Although replacement of the conserved U8 (FU8) with A or C disrupts the tertiary structure of tRNA(Val), it has only a small effect on the catalytic turnover number of valyl-tRNA synthetase, while reducing the affinity of the tRNA for enzyme. Analysis of the 19F chemical shift assignments of all 14 resonances in the spectrum of 5-fluorouracil-substituted tRNAVal indicated a strong correlation to tRNA secondary and tertiary structure. 5-Fluorouracil residues in loop regions gave rise to peaks in the central region of the spectrum, 4.4 to 4.9 parts per million (p.p.m.) downfield from free 5-fluorouracil. However, the signal from FU59, in the T-loop of tRNA(Val), was shifted more than 1 p.p.m. downfield, to 5.9 p.p.m., presumably because of the involvement of this fluorouracil in the tertiary interactions between the T and D-loops. The 19F chemical shift moved upfield, to the 2.0 to 2.8 p.p.m. range, when fluorouracil was base-paired with adenine in helical stems. This upfield shift was less pronounced for the fluorine of the FU7.A66 base-pair, located at the base of the acceptor stem, an indication that FU7 is only partially stacked on the adjacent G49 in the continuous acceptor stem/T-stem helix. An unanticipated finding was that the 19F resonances of 5-fluorouracil residues wobble base-paired with guanine were shifted 4 to 5 p.p.m. downfield of those from fluorouracil residues paired with A. In the 19F NMR spectra of all fluorinated tRNAs studied, the farthest downfield peak corresponded to FU55, which replaced the conserved pseudouridine normally found at this position.

Two high-performance liquid chromatographic analytical methods have been developed for the measurement of dl-sotalol or d-sotalol and l-sotalol in plasma, using dl-atenolol as internal standard. Quantitation of dl-sotalol was carried out, following solid-phase extraction, on a 5-microns C18 reversed-phase column, with a mobile phase containing acetonitrile, ion-pairing reagent and distilled water, using ultraviolet detection at 235 nm. Quantitation of d-sotalol and l-sotalol was based on derivatisation with the chiral agent S-(-)-alpha-methylbenzyl isocyanate, followed by chromatographic separation on a 3-microns C18 reversed-phase column, with a mobile phase containing methanol, glacial acetic acid and distilled water, with fluorimetric detection at 220 nm excitation and 300 nm emission. A preliminary application of the latter method suggests that the disposition of sotalol in humans is not enantioselective.

We prospectively studied 69 consecutive patients hospitalized with a primary diagnosis of acute left ventricular failure so as to assess the impact of vasodilators on incidence and morbidity of acute symptomatic left ventricular failure. The determinants of duration of hospitalization, in-hospital mortality and symptomatic status 2 months after discharge were examined. There were 9 in-hospital deaths (13%), and survival at 60 days was 77%. Median duration of hospitalization was 9 days, and 33% of the surviving patients remained in New York Heart Association functional class III-IV 60 days subsequent to discharge. Of the patients, 49 (76%) had previously received treatment for left ventricular failure: 30 (61%) of these had received vasodilators, most commonly angiotensin converting enzyme inhibitors and nitrates. Ischaemic chest pain was present in 34 (49%) of the patients. Acute utilization of vasodilators (45% of patients) was largely limited to nitrate therapy associated with ischaemic chest pain (P less than 0.01). Multiple logistic regression revealed previous left ventricular failure, advanced age and hypokalaemia as significant correlates of prolonged hospitalization (greater than 9 days). Previous left ventricular failure was also predictive of persistent severe disability two months subsequent to discharge. No factor was a significant predictor of in-hospital death. Although preceding treatment with digoxin and incremental angiotensin converting enzyme inhibitor therapy tended to predict brief hospitalization, the parameter of acute ischaemia, other biochemical anomalies and modes of acute or chronic therapy were not significant correlates of any end point. We conclude that preceding disability, rather than mode of treatment, predicts an adverse outcome in acute left ventricular failure.

Primary tumors of the brachial plexus are unusual. We describe a patient with a large schwannoma of the lower trunk of the brachial plexus that had the radiologic appearance of an apical lung mass. Use of a posterior subscapular approach as well as intraoperative nerve action potential recording permitted resection with spared function.