623 research outputs found

    Preparation of pyrimidin-2-one derivatives via base-mediated decomposition of uracil-analogues Fischer carbene complex

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    A practical and efficient synthesis of pyrimidin-2-one derivatives from Fischer carbene complex uracil-analogues through base-mediated elimination reactions is described. The scope of the protocol has been explored with the preparation of a variety of pyrimidin-2-one derivatives by base mediated demetallation of N-1 and N-3 substituted uracil Fischer carbene

    Bench-to-bedside review: preventive measures for contrast-induced nephropathy in critically ill patients

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    An increasing number of diagnostic imaging procedures requires the use of intravenous radiographic contrast agents, which has led to a parallel increase in the incidence of contrast-induced nephropathy. Risk factors for development of contrast-induced nephropathy include pre-existing renal dysfunction (especially diabetic nephropathy and multiple myeloma-associated nephropathy), dehydration, congestive heart failure and use of concurrent nephrotoxic medication (including aminoglycosides and amphotericin B). Because contrast-induced nephropathy accounts for a significant increase in hospital-acquired renal failure, several strategies to prevent contrast-induced nephropathy are currently advocated, including use of alternative imaging techniques (for which contrast media are not needed), use of (the lowest possible amount of) iso-osmolar or low-osmolar contrast agents (instead of high-osmolar contrast agents), hyperhydration and forced diuresis. Administration of N-acetylcysteine, theophylline, or fenoldopam, sodium bicarbonate infusion, and periprocedural haemofiltration/haemodialysis have been investigated as preventive measures in recent years. This review addresses the literature on these newer strategies. Since only one (nonrandomized) study has been performed in intensive care unit patients, at present it is difficult to draw firm conclusions about preventive measures for contrast-induced nephropathy in the critically ill. Further studies are needed to determine the true role of these preventive measures in this group of patients who are at risk for contrast-induced nephropathy. Based on the available evidence, we advise administration of N-acetylcysteine, preferentially orally, or theophylline intravenously, next to hydration with bicarbonate solutions

    On the hydrolysis of the Dysprosium(III) ion

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    The hydrolysis of the Dysprosium (III) (Dy 3+ ) ion has been investigated at 25°C in 1, 2 and 3 molal (Na)ClO4 medium through a combined potentiometric‐coulometric methodology. At each perchlorate concentration the formation constants of the complexes DyOH 2+ , Dy2(OH)2 4+ and Dy5(OH)9 6+ have been determined. The values have then been extrapolated to zero ionic strength by using the Specific Interaction Theory. Analogies with the hydrolysis mechanism of other lanthanides are pointed out. This paper is just the first to be reported of a series of studies undertaken with the aim to prove that a single mechanism of hydrolysis applies to all the trivalent lanthanides and probably to the corresponding actinides, too radioactive to be investigated directly

    Characterisation of Neisseria meningitidis C strains causing two clusters in the north of Italy in 2007 and 2008.

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    Two clusters of invasive meningococcal disease in the north of Italy both due to serogroup C/ST-11 clonal complex are here described. The objective of the investigation was to analyse the phenotype and the genotype of meningococci involved in the two clusters which were of national relevance due to the fatal outcome of the majority of cases (six of the total of 10 cases). All the strains were C:2a:P1.5 ST-11/ET-37 clonal complex. Two pulsed field gel electrophoresis (PFGE) and variable number tandem repeats (VNTR) profiles were identified, one for each cluster. VNTRs were different from those detected in Italy for C/ST-11 strains isolated from sporadic cases in the same period. This laboratory surveillance report highlights the importance and the crucial role of molecular characterisation to confirm the relatedness among meningococci responsible for clusters of cases

    Force-frequency relationship during dobutamine stress echocardiography predicts exercise tolerance and BNP levels in patients with chronic congestive heart failure

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    Purpose: D obutamine stress echocardiography (DSE) is widely used to evaluate myocardial contractile reserve; it provides prognostic information in patients with chronic congestive heart failure (CHF). The force?frequency relationship (FFR) is a method for evaluate LV contractility during DSE . The aim of our study is to assess the relationship among FFR, BNP levels, and aerobic exercise capacity in CHF patients. Methods and materials: 37 CHF patients (age 67?8 years, 54% with an ischemic etiology), underwent high dose DSE (up to 40 m g/kg/min). FFR was determined as a ratio between systolic cuff pressure and end-systolic volume (biplane using a Simposon rule) assessed at baseline and peak DSE . BNP levels were determined on blood samples withdrawn at baseline. After a few hours, CHF patients underwent cardiopulmonary exercise test with expired gas measurement. Results: Mean ejection fraction was 32?7% and NHYA class 2.5?0.6. FFR was directly related to peak oxygen consumption (Figure Left), LV ejection fraction (r=0.398, p=0.015) and mitral annulus peak systolic velocity (r=0.428, p=0.013). FFR was inversely related to NYHA class (r=-0.43, p=0.013), LV end-diastolic diameter (r=-0.377, p=0.022), LV intraventricular dyssynchrony (r=-0.394, p=0.016), and BNP levels (Figure Right). At multiple regression analysis, FFR (B=0.502, p= 0.004) and E/Ea ratio (B=-0.336, p=0.044) were the best predictors of exercise tolerance. Conclusions: In patients with stable CHF, impaired myocardial contractility during DSE is related to higher BNP levels and poorer exercise tolerance

    Interventional cardiology : Cost-effectiveness of PCI guided by fractional flow reserve

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    Coronary revascularization strategies have been evaluated in numerous clinical trials. As coronary revascularization has become more common, concerns over financial costs have increased

    Impact of cardiac hybrid single-photon emission computed tomography/computed tomography imaging on choice of treatment strategy in coronary artery disease

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    Aims Cardiac hybrid imaging by fusing single-photon emission computed tomography (SPECT) myocardial perfusion imaging with coronary computed tomography angiography (CCTA) provides important complementary diagnostic information for coronary artery disease (CAD) assessment. We aimed at assessing the impact of cardiac hybrid imaging on the choice of treatment strategy selection for CAD. Methods and results Three hundred and eighteen consecutive patients underwent a 1 day stress/rest (99m)Tc-tetrofosmin SPECT and a CCTA on a separate scanner for evaluation of CAD. Patients were divided into one of the following three groups according to findings in the hybrid images obtained by fusing SPECT and CCTA: (i) matched finding of stenosis by CCTA and corresponding reversible SPECT defect; (ii) unmatched CCTA and SPECT finding; (iii) normal finding by both CCTA and SPECT. Follow-up was confined to the first 60 days after hybrid imaging as this allows best to assess treatment strategy decisions including the revascularization procedure triggered by its findings. Hybrid images revealed matched, unmatched, and normal findings in 51, 74, and 193 patients. The revascularization rate within 60 days was 41, 11, and 0% for matched, unmatched, and normal findings, respectively (P< 0.001 for all inter-group comparisons). Conclusion Cardiac hybrid imaging with SPECT and CCTA provides an added clinical value for decision making with regard to treatment strategy for CAD

    A population-based study of transformed marginal zone lymphoma:identifying outcome-related characteristics

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    Histological transformation of marginal zone lymphoma (tMZL) into diffuse large B-cell lymphoma is associated with poor outcomes. Clinical characteristics associated with transformation risk and outcome after transformation are largely unknown due to scarcity of data. In this population-based study, competing risk analyses were performed to elucidate clinical characteristics associated with developing transformation among 1793 MZL patients using the Netherlands Cancer Registry. Cox regression analyses were performed to elucidate clinical characteristics associated with risk of relapse and mortality after transformation. Transformation occurred in 75 (4%) out of 1793 MZL patients. Elevated LDH and nodal MZL subtype at MZL diagnosis were associated with an increased risk, and radiotherapy with a reduced risk of developing tMZL. Most tMZL patients received R-(mini)CHOP (n = 53, 71%). Age &gt;60 years and (immuno)chemotherapy before transformation were associated with an increased risk of relapse and mortality after transformation. Two-year progression-free survival (PFS) and overall survival (OS) were 66% (95% CI 52-77%) and 75% (95% CI 62-85%) for R-(mini)CHOP-treated tMZL patients, as compared to a PFS and OS both of 41% (95% CI 19-63%) for patients treated otherwise. Our study offers comprehensive insights into characteristics associated with transformation and survival after transformation, thereby optimizing guidelines and patient counseling.</p

    Utilizing Risk Scores in Determining the Optimal Revascularization Strategy for Complex Coronary Artery Disease

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    Percutaneous coronary intervention (PCI) of multivessel and/or left main stem disease have been shown to be potentially legitimate revascularization alternatives in appropriately selected patients. Risk stratification is an important component in guiding patients to identify the most appropriate revascularization modality (PCI or coronary artery bypass grafting [CABG]) in conjunction with the Heart Team. The aim of this paper is to give the clinician a concise overview of the important established and evolving contemporary risk models in aiding this decision-making process. Risk models, based on clinical and anatomical variables alone, the novel concept of functional anatomical risk scores, and risk models combining aspects from both clinical and anatomical scores, are all discussed. The emerging concepts of the patient-empowered risk/benefit tradeoff between PCI and CABG to help personalize the choice of revascularization modality are also explored
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