Effective Heisenberg Model and Exchange Interaction for Strongly Correlated Systems.

We consider the extended Hubbard model and introduce a corresponding Heisenberg-like problem written in terms of spin operators. The derived formalism is reminiscent of Anderson's idea of the effective exchange interaction and takes into account nonlocal correlation effects. The results for the exchange interaction and spin susceptibility in the magnetic phase are expressed in terms of single-particle quantities. This fact not only can be used for realistic calculations of multiband systems but also allows us to reconsider a general description of many-body effects in the most interesting physical regimes, where the physical properties of the system are dominated by collective (bosonic) fluctuations. In the strongly spin-polarized limit, when the local magnetic moment is well defined, the exchange interaction reduces to a standard expression of the density functional theory that has been successfully used in practical calculations of magnetic properties of real materials.

Determining the health-related quality of life in individuals with haemophilia in developing economies: results from the Brazilian population.

INTRODUCTION: Several studies show the negative impact of haemophilia in health-related quality of life (HRQOL). This issue is not well explored in developing countries. OBJECTIVES: This cross-sectional study aimed to evaluate the HRQOL and its associated factors in patients with haemophilia A/B in Brazil. Data were collected by questionnaire and in medical records, including a Portuguese version of Haem-A-Qol. RESULTS: Brazilian patients were invited to the study and 175 participants (147 haemophilics A and 28 haemophilics B) were included. The total score of the Haem-A-QoL had a median of 36.96 (range of 0-100), with worse performance in 'sport and leisure' and best on 'relationships' fields. HRQOL was worst among the older participants, the less educated, non-white, non-working, who were hospitalized in the last year, who did not have a single medical consultation and among those with the highest number of affected joints. Moreover, patients with hepatitis B had a significantly worse HRQOL in the domain 'sports and leisure', also observed in married patients. Otherwise, married individuals reported better HRQOL on 'dealing with the disease' domain. Patients with haemophilia B reported worse HRQOL in the domain 'self-perception'. CONCLUSION: The results obtained could be helpful in guidance of haemophilia treatment which is determinant to improve HRQoL of the most vulnerable groups of patients. This work also reinforced the relevance of joint bleeds in all aspects of HRQoL in haemophilic patients. The use of prophylactic factor concentrates and multidisciplinary treatments could contribute to improve the quality of life in haemophilia.

Intrinsic Charge Carrier Mobility in Single-Layer Black Phosphorus.

We present a theory for single- and two-phonon charge carrier scattering in anisotropic two-dimensional semiconductors applied to single-layer black phosphorus (BP). We show that in contrast to graphene, where two-phonon processes due to the scattering by flexural phonons dominate at any practically relevant temperatures and are independent of the carrier concentration n, two-phonon scattering in BP is less important and can be considered negligible at n≳10^{13} cm^{-2}. At smaller n, however, phonons enter in the essentially anharmonic regime. Compared to the hole mobility, which does not exhibit strong anisotropy between the principal directions of BP (µ_{xx}/µ_{yy}∼1.4 at n=10^{13} cm^{-2} and T=300 K), the electron mobility is found to be significantly more anisotropic (µ_{xx}/µ_{yy}∼6.2). Absolute values of µ_{xx} do not exceed 250 (700) cm^{2} V^{-1} s^{-1} for holes (electrons), which can be considered as an upper limit for the mobility in BP at room temperature.

Urban daily life routines and human exposure to environmental discomfort.

This study suggests a shift in focus from studying environmental discomfort in urban strategic stations, from which average results for the city or specific results for selected sites are deduced, and from measuring environmental conditions in fixed monitoring stations to a study in which we monitor, with mobile portable sensors, the exposure of people to environmental sources of discomfort while performing their daily life activities. Significant variations in sense of discomfort were measured in this study, and almost half of this variability was found to be explained while four independent environmental variables were considered: air quality (concentrations of CO), noise level, climatic variables (thermal load), and social loads. The study conducted in the city of Tel Aviv, which suffers from hot, humid summers and cool winters, and noise levels that reach the average levels of 85 dB, and relatively lower levels of exposure to the other potential stressors. These levels of combined exposures result in moderate levels of discomfort for young, healthy people once they experience the more stressing environments in the city. It is shown also that noise from other people is the most salient source of discomfort in Tel Aviv. Levels of discomfort accumulate during the working hours, either due to the impact of social loads or noise, but the subjects showed good coping abilities that enabled them to recover in late afternoons. It seems that thermal load does not have immediate impact, but rather cumulative ones, mainly during transitional seasons when subjects are less adaptive to extreme changes in weather.

Ki-67 expression in non-tumour epithelium adjacent to oral cancer as risk marker for multiple oral tumours.

OBJECTIVE: The aim of this study was to determine whether the differential assessment of epithelial proliferation is useful to diagnose premalignant fields and assess the risk of multiple tumours. MATERIAL AND METHODS: We analysed 83 oral carcinomas with associated non-tumour epithelium classified as distant or close according to its distance (> or <1 cm) from the invasion point, and as squamous hyperplasia, mild, moderate, severe dysplasia or carcinoma in situ. Twenty-five healthy oral mucosa samples were used as controls. An immunohistochemical technique was applied using Mib-1. Ki-67 in premalignant epithelium was assessed in basal layer, parabasal layer, medium and upper third. RESULTS: Parabasal expression was significantly higher or showed a tendency to be higher in close and distant epithelia with any histological grade than in the controls. Parabasal Ki-67 significantly differed between distant epithelia associated with multiple vs single tumours (P < 0.001) and between distant epithelia associated with multiple tumours vs controls (P < 0.001). This difference was not observed between distant epithelia associated with single tumours and controls (P = 0.175). The cut-off point that differentiated epithelia associated with multiple tumours was >50% of Ki-67 + parabasal cells in distant epithelia, which yielded 0.88 sensitivity and 0.79 specificity. CONCLUSIONS: The concept of a precancerous field may be linked to an increase in the proliferative activity of parabasal cells.

Lipases of Endophytic Fungi Stemphylium lycopersici and Sordaria sp.: Application in the synthesis of solketal derived Monoacylglycerols.

Monoacylglycerols (MAGs) are amphiphilic compounds with wide range of applications such as emulsifiers, solubility agents, and chiral building blocks. These compounds are currently produced by chemical approaches involving alkaline glycerolysis or esterification under high temperatures and pressure, resulting in low yields and with by-products. Lipase-catalyzed processes have been alternative tools to provide more ecological approaches since MAGs can be obtained under milder reaction conditions and with higher selectivity. However, just a few papers have been explored the potential of endophytic fungi as lipase sources. In this work we summarized the screening of lipolytic activity of endophytic fungus S. lycopersici and Sordaria spp isolated from vegetal species collected in Jurubatiba Sandbank National Park, RJ, Brazil, as well as its applications as biocatalysts on the lipase-catalyzed synthesis of solketal 1-MAG derivatives. As a result, the crude enzymatic extract of S. lycopersici showed 98 U/mL and 110 U/mL of hydrolytic activity after 72 h and 96 h, respectively, against 74 U/mL (96 h) and, 86 U/mL (120 h) expressed by enzymatic extract of Sordaria spp.. Concerning the esterification activity, both crude enzymatic extracts and lyophilized fungi showed about 80 % conversion into ethyl oleate, in 100 min. On solketal derived 1-MAG synthesis, S. lycopersici both lyophilized and immobilized in polyurethane (PU) forms showed more than 75 % of conversion in the presence and absence of organic solvents. On MAG recycle assays, the PU biocatalyst could be reused after five reaction cycles while for the ethyl oleate synthesis, PU biocatalyst could be reused after six reaction cycles. Both microorganisms, immobilized in polyurethane, were successfully applied as biocatalysts in esterification reactions for solketal 1-MAG derivative production, in a solvent-free media.

Inner but not outer membrane leaflets control the transition from glycosylphosphatidylinositol-anchored influenza hemagglutinin-induced hemifusion to full fusion.

Cells that express wild-type influenza hemagglutinin (HA) fully fuse to RBCs, while cells that express the HA-ectodomain anchored to membranes by glycosylphosphatidylinositol, rather than by a transmembrane domain, only hemifuse to RBCs. Amphipaths were inserted into inner and outer membrane leaflets to determine the contribution of each leaflet in the transition from hemifusion to fusion. When inserted into outer leaflets, amphipaths did not promote the transition, independent of whether the agent induces monolayers to bend outward (conferring positive spontaneous monolayer curvature) or inward (negative curvature). In contrast, when incorporated into inner leaflets, positive curvature agents led to full fusion. This suggests that fusion is completed when a lipidic fusion pore with net positive curvature is formed by the inner leaflets that compose a hemifusion diaphragm. Suboptimal fusion conditions were established for RBCs bound to cells expressing wild-type HA so that lipid but not aqueous dye spread was observed. While this is the same pattern of dye spread as in stable hemifusion, for this "stunted" fusion, lower concentrations of amphipaths in inner leaflets were required to promote transfer of aqueous dyes. Also, these amphipaths induced larger pores for stunted fusion than they generated within a stable hemifusion diaphragm. Therefore, spontaneous curvature of inner leaflets can affect formation and enlargement of fusion pores induced by HA. We propose that after the HA-ectodomain induces hemifusion, the transmembrane domain causes pore formation by conferring positive spontaneous curvature to leaflets of the hemifusion diaphragm.

A role for the substance P/NK-1 receptor complex in cell proliferation and apoptosis in oral lichen planus.

OBJECTIVES: To determine whether substance P (SP) and NK-1 receptor (NK-1R) are expressed in oral lichen planus (OLP) and are related to cell proliferation and apoptosis in this disease. MATERIAL AND METHODS: Tissue samples from 50 OLP patients and 26 healthy controls were studied. Immunohistochemistry was performed with anti-SP, anti-NK-1R, anti-ki-67 and anti-caspase-3 monoclonal antibodies and the clinical and pathological data of the OLP patients were evaluated. RESULTS: With the exception of NK-1R expression in epithelial cell membrane and cytoplasm, all markers were more frequently present in OLP patients than in controls (P < 0.05). Higher cytoplasmatic expression of NK-1R was associated with higher epithelial expression of caspase-3 (P < 0.05). Higher epithelial expression of NK-1R and SP was associated with higher suprabasal and basal epithelial expression of ki-67 (P < 0.05 and P < 0.005, respectively). CONCLUSIONS: Actions of the SP/NK-1R complex may contribute to the immune disorder underlying OLP and trigger stimuli to induce cell proliferation. These results indicate that this complex might play a role in the malignant transformation of OLP.

Understanding the electronic structure and magnetism of correlated nanosystems.

In this paper we review recent developments towards a realistic description of the electronic structure and magnetism of correlated nanosystems. A new class of so-called continuous-time solvers for the quantum impurity problem is discussed, which provides a numerically exact solution without systematic errors due to imaginary time discretization. These solvers are able to handle general interactions, like the full Coulomb vertex. We further show how four-point or higher-order correlation functions of the impurity problem can be computed. This allows the calculation of dynamical susceptibilities which provide information about spin excitations. Moreover, we discuss a principally new many-body scheme recently proposed for the description of non-local correlations in strongly correlated systems. This approach provides a basis for a many-body description of extended correlated nanostructures on a substrate.

Defining the optimal activated clotting time during percutaneous coronary intervention: aggregate results from 6 randomized, controlled trials.

BACKGROUND: Unfractionated heparin has been the primary anticoagulant therapy for percutaneous coronary intervention for >20 years. Despite the availability of rapid "point of care" testing, little clinical data defining the optimal level of anticoagulation are available. Furthermore, recent reports have advocated the use of low-dose heparin regimens in the absence of large-scale, well-conducted studies to support this practice. METHODS AND RESULTS: We pooled the data from 6 randomized, controlled trials of novel adjunctive antithrombotic regimens for percutaneous coronary interventions in which unfractionated heparin constituted the control arm. Patients were divided into 25-s intervals of activated clotting times (ACTs), from <275 s to >476 s. In a total of 5216 patients, the incidence of death, myocardial infarction, or any revascularization and major or minor bleeding at 7 days were calculated for each group and compared. An ACT in the range of 350 to 375 s provided the lowest composite ischemic event rate of 6.6%, or a 34% relative risk reduction in 7-day ischemic events compared with rates observed between 171 and 295 s by quartile analysis (P=0.001). CONCLUSIONS: Contrary to recent reports, the optimal suppression of ischemic events with unfractionated heparin therapy in patients undergoing percutaneous coronary intervention demands treatment to ACT levels that are substantially higher than currently appreciated. These data define a goal for heparin dosing within coronary interventions and establish a benchmark of optimal unfractionated heparin therapy against which future trials of novel antithrombotic regimens in percutaneous interventions can be compared.

beta-blockers before percutaneous coronary intervention do not attenuate postprocedural creatine kinase isoenzyme rise.

BACKGROUND: beta-blocker (BB) use reduces infarct size in spontaneously occurring nonreperfused infarcts but probably does not change infarct size in patients treated with reperfusion therapy. A recent observational study suggested that BB use concurrent with percutaneous coronary intervention (PCI) decreased the risk of creatine kinase (CK)-MB elevation. The cogency of such a conclusion is dependent on the ability to risk-adjust for the multiple differences in patients treated with and without BBs. METHODS AND RESULTS: Using propensity score and multivariate regression analyses, 6200 consecutive patients were analyzed to assess the relationship between BB use before PCI and per protocol-measured CK and CK-MB rise. There were several highly significant (P<0.001) differences between patients with and without BB treatment (eg, age, prior infarction, unstable angina). Maximum CK and CK-MB levels were higher in patients taking BBs (CK median, 95 U [interquartile range: 61, 175]; CK-MB, 3 U [2, 5]) than in patients not taking BBs (CK, 91 U [60, 157]; CK-MB, 3 U [2, 4]) (P=0.011 and P=0.021 for CK and CK-MB, respectively). After adjustment for significant differences in baseline characteristics there was no difference in either maximum CK rise (P=0.21) or maximum CK-MB rise (P=0.99). CONCLUSIONS: The results of this large observation study do not support the contention that BB use before PCI decreases myocardial injury.

Pronounced benefit of coronary stenting and adjunctive platelet glycoprotein IIb/IIIa inhibition in complex atherosclerotic lesions.

BACKGROUND: Previous trials testing stents compared with balloon angioplasty excluded patients with complex lesions and did not assess the effect of adjunctive platelet IIb/IIIa inhibition. This analysis sought to assess the effect of stenting and abciximab specifically for patients with complex lesions. METHODS AND RESULTS: Patients with complex lesions (long, tandem, severely calcified, restenotic, thrombotic, or ostial; total occlusions; bifurcations; saphenous vein grafts; and multivessel interventions) from the Evaluation of PTCA to Improve Long-Term Outcome by c7E3 GP IIb/IIIa Receptor Blockade (EPILOG) and the Evaluation of Platelet IIb/IIIa Inhibitor for Stenting (EPISTENT) trials were included in the analysis. The 1-year combined death or myocardial infarction rates in the 4 treatment groups were as follows: balloon angioplasty/placebo, 14.2%; stent/placebo, 15.8%; balloon angioplasty/abciximab, 7.6%; and stent/abciximab, 8.0% (P<0.001). Death rates were 3.2%, 3.1%, 2.1%, and 0.5%, respectively (P=0.03). The incidence of target vessel revascularization at 1 year was 30.5%, 18.0%, 24.4%, and 19.7% in the 4 groups, respectively (P<0.001). After adjustment for baseline differences, multivariate analysis demonstrated that the rate of death or myocardial infarction was independently reduced by balloon angioplasty/abciximab (hazard ratio, 0.51; P<0.001) and stent/abciximab (hazard ratio, 0.60; P=0.02) but was not affected by the use of stents alone. Conversely, target vessel revascularization was reduced by stent/placebo (hazard ratio, 0.53; P<0.001), stent/abciximab (hazard ratio, 0.58; P<0.001), and balloon angioplasty/abciximab (hazard ratio, 0.74; P=0.006) compared with balloon angioplasty/placebo, respectively. CONCLUSIONS: The combination of stenting and abciximab during percutaneous coronary interventions for patients with angiographically complex lesions confers additive long-term benefit with respect to death, myocardial infarction, and target vessel revascularization.

Does coronary angiography before emergency aortic surgery affect in-hospital mortality?

OBJECTIVES: To study the relationship between coronary angiography and in-hospital mortality in patients undergoing emergency surgery of the aorta without a history of coronary revascularization or coronary angiography before the onset of symptoms. BACKGROUND: In the setting of acute ascending aortic dissection warranting emergency aortic repair, coronary angiography has been considered to be desirable, if not essential. The benefits of defining coronary anatomy have to be weighed against the risks of additional delay before surgical intervention. METHODS: Retrospective analysis of patient charts and the Cardiovascular Information Registry (CVIR) at the Cleveland Clinic Foundation. RESULTS: We studied 122 patients who underwent emergency surgery of the aorta between January 1982 and December 1997. Overall, in-hospital mortality was 18.0%, and there was no significant difference between those who had coronary angiography on the day of surgery compared with those who had not (No: 16%, n = 81 vs. Yes: 22%, n = 41, p = 0.46). Multivariate analysis revealed that a history of myocardial infarction (MI) was the only predictor of in-hospital mortality (relative risk: 4.98 95% confidence interval: 1.48-16.75, p = 0.009); however, coronary angiography had no impact on in-hospital mortality in patients with a history of MI. Furthermore, coronary angiography did not significantly affect the incidence of coronary artery bypass grafting (CABG) during aortic surgery (17% vs. 25%, Yes vs. No). Operative reports revealed that 74% of all CABG procedures were performed because of coronary dissection, and not coronary artery disease. CONCLUSIONS: These data indicate that determination of coronary anatomy may not impact on survival in patients undergoing emergency surgery of the aorta and support the concept that once diagnosed, patients should proceed as quickly as possible to surgery.

Progression of aortic stenosis in 394 patients: relation to changes in myocardial and mitral valve dysfunction.

OBJECTIVES: This study reports the results of echocardiographic follow-up in a large cohort of patients with aortic stenosis and correlates the progression of aortic stenosis with changes in the degree of mitral regurgitation and left ventricular hypertrophy and systolic dysfunction. BACKGROUND: Progressive aortic stenosis often causes left ventricular dysfunction and mitral regurgitation. Doppler echocardiography has greatly assisted in the noninvasive evaluation and follow-up of aortic stenosis. Nevertheless, the longitudinal follow-up of patients with Doppler echocardiography for the progression of aortic stenosis and the significance of progressive ventricular hypertrophy and mitral regurgitation have not been reported. METHODS: Serial Doppler echocardiography was performed in 394 consecutive patients with valvular aortic stenosis at baseline and after a mean follow-up period of 37 +/- 16 months. Mean and peak aortic gradients, aortic valve area, left ventricular systolic and diastolic diameters and percent area change (shortening fraction) were expressed as continuous variables, and systolic dysfunction, mitral regurgitation, ventricular hypertrophy and filling properties were tabulated as categoric variables using a semiquantitative grading system. RESULTS: Peak and mean gradients increased by an average of 8.3 and 6.3 mm Hg/year, respectively; end-systolic and end-diastolic diameters increased by 1.9 and 1.6 mm/year, respectively; and aortic valve area decreased by 0.14 cm2/year during the follow-up interval (p < 0.001 for all), indicating progression of aortic stenosis and ventricular dilation. Patients in the lowest quartile of aortic valve area and highest quartiles of mean and peak gradients had the least change compared with those in the highest quartile of aortic valve area and lowest quartile of mean and peak gradients (p < 0.01 for all). Patients with more mitral regurgitation at follow-up than at baseline had higher mean percent increase in mean and peak gradients as well as more progression of ventricular dilation and worsening systolic function compared with those with stable or improving mitral regurgitation (p < 0.05 for all). Similarly, subjects with worsening left ventricular hypertrophy had larger mean percent increase in mean and peak gradients than those with stable left ventricular hypertrophy (p < 0.01) but maintained stable ventricular volumes and systolic function. There was no correlation between the amount of change in mean or peak gradients and degree of deterioration in systolic function. CONCLUSIONS: Aortic stenosis progresses predictably over time; however, systolic dysfunction is an inconsistent marker of the hemodynamic consequences of severe aortic stenosis. As an adaptive response to pressure overload, progressive hypertrophy appears to prevent ventricular dilation and development or worsening of mitral regurgitation. Conversely, progressive mitral regurgitation may be seen as a maladaptive consequence of increasing aortic stenosis.

Atenolol use and clinical outcomes after thrombolysis for acute myocardial infarction: the GUSTO-I experience. Global Utilization of Streptokinase and TPA (alteplase) for Occluded Coronary Arteries.

OBJECTIVES: We assessed the use and effects of acute intravenous and later oral atenolol treatment in a prospectively planned post hoc analysis of the GUSTO-I dataset. BACKGROUND: Early intravenous beta blockade is generally recommended after myocardial infarction, especially for patients with tachycardia and/or hypertension and those without heart failure. METHODS: Besides one of four thrombolytic strategies, patients without hypotension, bradycardia or signs of heart failure were to receive atenolol 5 mg intravenously as soon as possible, another 5 mg intravenously 10 min later and 50 to 100 mg orally daily during hospitalization. We compared the 30-day mortality of patients given no atenolol (n=10,073), any atenolol (n=30,771), any intravenous atenolol (n=18,200), only oral atenolol (n=12,545) and both intravenous and oral drug (n=16,406), after controlling for baseline differences and for early deaths (before oral atenolol could be given). RESULTS: Patients given any atenolol had a lower baseline risk than those not given atenolol. Adjusted 30-day mortality was significantly lower in atenolol-treated patients, but patients treated with intravenous and oral atenolol treatment vs. oral treatment alone were more likely to die (odds ratio, 1.3; 95% confidence interval, 1.0 to 1.5; p=0.02). Subgroups had similar rates of stroke, intracranial hemorrhage and reinfarction, but intravenous atenolol use was associated with more heart failure, shock, recurrent ischemia and pacemaker use than oral atenolol use. CONCLUSIONS: Although atenolol appears to improve outcomes after thrombolysis for myocardial infarction, early intravenous atenolol seems of limited value. The best approach for most patients may be to begin oral atenolol once stable.

Value of tongue biting in the diagnosis of seizures.

BACKGROUND: Seizures are rarely witnessed by physicians, and the diagnosis is usually made on the basis of the history. Tongue biting is classically considered to favor a diagnosis of epileptic seizure. The usefulness of tongue biting in the differential diagnosis of seizures was evaluated. METHODS: A prospective study of the presence of oral lacerations in 106 consecutive patients admitted to our Epilepsy Monitoring Unit and a retrospective study of a population of 45 patients with syncope were performed. The relationship between tongue biting and diagnosis (epileptic vs nonepileptic events) was analyzed. RESULTS: Of the 106 monitored patients, 63 had episodes characterized by bilateral motor activity, complete loss of consciousness, or both; 34 patients had epileptic seizures, while 29 patients had exclusively nonepileptic episodes. Eight patients suffered an oral laceration; all involved the side of the tongue, and all had documented epileptic seizures. Of the 45 patients with syncope, in only one was the tongue lacerated, and this was at the tip. Tongue biting had a sensitivity of 24% and a specificity of 99% for the diagnosis of generalized tonic-clonic seizures. Lateral tongue biting was 100% specific to grand mal seizures. CONCLUSION: Tongue biting, particularly if it is lateral, is highly specific to generalized tonic-clonic seizures.

Significance of Preventing Primary Infections by Didymella rabiei and Development of a Model to Estimate the Maturity of Pseudothecia.

The significance of preventing primary infections resulting from the teleomorph stage of Didymella rabiei was tested in field experiments in 1998 and 2000. Control efficacy was greater and yield and its components were higher in plots where the fungicide difenoconazole had been sprayed in time to protect the plants from infections resulting from airborne ascospores than in plots where sprays were not applied on time. Forty empirical models reflecting the influence of temperature and interrupted wetness on initial maturation of D. rabiei pseudothecia were developed and verified by using data recorded in chickpea fields in 1998. Seven of the models then were validated with data recorded in 1999 and 2000. The following model provided the best predictions: starting at the beginning of the rainy season (October to December), the predictor of the model was assigned one severity value unit when there was a rain event (1 day or more) with ≥10 mm of rain and an average daily temperature (during the rainy days) of ≤15°C. According to the model, pseudothecia mature after accumulation of six severity values and ascospores will be discharged during the following rain.

Transient Elastography for Assessment of Liver Fibrosis and Steatosis: An Evidence-Based Analysis.

BACKGROUND: Liver fibrosis is a sign of advanced liver disease and is often an indication for treatment. The current standard for diagnosing liver fibrosis and steatosis is biopsy, but noninvasive alternatives are available; one of the most common is transient elastography (FibroScan). OBJECTIVES: The objective of this analysis was to assess the diagnostic accuracy and clinical utility of transient elastography alone for liver fibrosis and with controlled attenuation parameter (CAP) for steatosis in patients with hepatitis C virus, hepatitis B virus, nonalcoholic fatty liver disease, alcoholic liver disease, or cholestatic diseases. The analysis also aimed to compare the diagnostic accuracy of transient elastography with two alternative noninvasive technologies: FibroTest and acoustic force radiation impulse (ARFI). DATA SOURCES: Ovid MEDLINE, Ovid MEDLINE In-Process, Ovid Embase, and all EBM databases were searched for all studies published prior to October 2, 2014. REVIEW METHODS: An overview of reviews was conducted using a systematic search and assessment approach. The results of the included systematic reviews were summarized, analyzed, and reported for outcomes related to diagnostic accuracy and clinical utility as a measure of impact on diagnoses, therapeutic decisions, and patient outcomes. RESULTS: Fourteen systematic reviews were included, summarizing more than 150 studies. The reviews demonstrated that transient elastography (with or without CAP) has good diagnostic accuracy compared to biopsy for the assessment of liver fibrosis and steatosis. Acoustic force radiation impulse and FibroTest were not superior to transient elastography. LIMITATIONS: None of the included systematic reviews reported on the clinical utility of transient elastography. CONCLUSIONS: Transient elastography (with or without CAP) offers a noninvasive alternative to biopsy for the assessment of liver fibrosis and steatosis, given its comparable diagnostic accuracy.

Angiographic correlates of cardiac death and myocardial infarction complicating major nonthoracic vascular surgery.

In a case-control study of 63 patients undergoing major nonthoracic vascular surgery with prior cardiac catheterization, we found total coronary occlusion serving viable myocardium and "nonobstructive" lesions to be the most common proximate cause of perioperative myocardial infarction or death. The extent of coronary disease by several measures was significantly correlated with adverse outcome, and prior bypass surgery appeared to be protective.

Comparison of stenting and balloon angioplasty for narrowings in aortocoronary saphenous vein conduits in place for more than five years.

To compare the 1 year outcome of Palmaz-Schatz stent implantation versus balloon angioplasty for treatment of obstructive lesions in saphenous vein grafts, we combined databases from the Palmaz-Schatz vein graft stent registry and the coronary angioplasty arm of the Coronary Angioplasty Versus Excisional Atherectomy Trial II (CAVEAT II) for comparison of baseline characteristics, procedural variables, in-hospital events and 1-year composite end point of death, Q-wave myocardial infarction, and repeat target vessel revascularization. De novo graft lesions not involving the ostia were treated with stent implantation in 377 patients and with coronary angioplasty in 156 patients. The patients were comparable in age, coronary risk profile, interval from bypass surgery (9 +/- 4 years), and reference vessel diameter. The in-hospital composite end point of death, myocardial infarction, and emergency revascularization was lower in the stent group (10%) than in the angioplasty cohort (17%) (p = 0.059). At 1 year, the patients in the stent group had a markedly lower incidence of the composite end point of death, myocardial infarction, or revascularization (23% vs 45%, p <0.001). In this nonrandomized comparison with balloon angioplasty, the treatment of lesions in saphenous vein grafts appears to be favorably influenced by Palmaz-Schatz stent implantation, in terms of in-hospital events and clinical restenosis at 1 year follow-up.