396 research outputs found

    Long-Term Safety of a Novel Antianginal Agent in Patients With Severe Chronic Stable Angina The Ranolazine Open Label Experience (ROLE)

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    ObjectivesThis report describes safety and tolerability data from 746 chronic angina patients treated in the ROLE (Ranolazine Open Label Experience) program.BackgroundRanolazine treats angina without depressing hemodynamic status. The long-term safety and tolerability of ranolazine have not been previously reported.MethodsPatients with severe functional impairment from angina (mean Duke Treadmill Score [DTS] of −14.4) who completed 1 of 2 randomized treadmill trials entered the ROLE program. Ranolazine was titrated to optimal dosages between 500 and 1,000 mg twice daily. Physical examination, laboratory tests, and adverse event reporting were performed periodically. We conducted analyses to evaluate possible predictors of ranolazine intolerance, such as advanced age, diabetes, poor exercise tolerance, or history of myocardial infarctions or congestive heart failure (CHF). The ROLE program’s mortality was compared against the DTS predictive model and other contemporary cohorts of high-risk CHD patients.ResultsMean follow-up was 2.82 years. Two years after initial dosing, 571 patients (76.7%) remained on therapy and 72 patients (9.7%) discontinued ranolazine due to adverse events. Among 6 factors evaluated, only age ≥64 years predicted for higher withdrawal rates. Patients with a history of CHF had lower withdrawal rates. Mean QTc interval was prolonged by 2.4 ms. No treatment discontinuations occurred due to QTc prolongation, and no Torsades de Pointes was reported. Sixty-four deaths occurred during a total of 2,102 patient-years (3.0% annually) during the ROLE program. When extending observations to all patients exposed to ranolazine during the double-blind trials (n = 972) preceding the ROLE program, annual mortality was 2.8% compared with >5% as predicted by DTS.ConclusionsLong-term therapy with ranolazine seems well tolerated in high-risk CHD patients. Survival analyses suggest that symptomatic improvements attributable to ranolazine are not offset by increased mortality

    Drug-induced acute kidney injury in children

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    Acute kidney injury (AKI) is a serious problem occurring in anywhere between 8 and 30% of children in the intensive care unit. Up to 25% of these cases are believed to be the result of pharmacotherapy. In this review we have focused on several relevant drugs and/or drug classes, which are known to cause AKI in children, including cancer chemotherapeutics, non-steroidal anti-inflammatory drugs and antimicrobials. AKI demonstrates a steady association with increased long term risk of poor outcomes including chronic kidney disease and death as determined by the extent of injury. For this reason it is important to understand the causality and implications of these drugs and drug classes. Children occupy a unique patient population, advocating the importance of understanding how they are affected dissimilarly compared with adults. While the kidney itself is likely more susceptible to injury than other organs, the inherent toxicity of these drugs also plays a major role in the resulting AKI. Mechanisms involved in the toxicity of these drugs include oxidative damage, hypersensitivity reactions, altered haemodynamics and tubule obstruction and may affect the glomerulus and/or the tubules. Understanding these mechanisms is critical in determining the most effective strategies for treatment and/or prevention, whether these strategies are less toxic versions of the same drugs or add-on agents to mitigate the toxic effect of the existing therapy

    Highly nondegenerate four-wave mixing and gain nonlinearity in a strained multiple-quantum-well optical amplifier

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    Highly nondegenerate four-wave mixing was investigated in a 1.5 µm compressively strained multi-quantum-well semiconductor traveling-wave optical amplifier at detuning frequencies up to 600 GHz. A gain nonlinearity with a characteristic relaxation time of 650 fs was determined from the data, and the nonlinear gain coefficient was estimated to be 4.3×10^–23 m^3. Dynamic carrier heating is believed to be the major source of nonlinear gain in this device at the wavelengths investigated

    Effect of the proprotein convertase subtilisin/kexin type 9 inhibitor evolocumab on glycemia, body weight, and new-onset diabetes mellitus

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    Statin therapy modestly increases new-onset diabetes risk. The effect of proprotein convertase subtilisin/kexin type 9 inhibition on new-onset diabetes, glycemia, and weight remains unclear. We studied the effects of the proprotein convertase subtilisin/kexin type 9 inhibitor evolocumab on fasting plasma glucose, glycated hemoglobin, weight, and new-onset diabetes mellitus. We pooled 1-year (48-week) data for participants who had completed an evolocumab parent study before entering an open-label extension (OLE) trial. Data were available for 4,802 participants (1,602 on standard of care [SOC]; 3,200 on evolocumab plus SOC) in 2 OLE trials. Evolocumab lowered low-density lipoprotein cholesterol by approximately 60% compared with SOC alone. Over the first year of the OLE trials, there was no difference in median (Q1, Q3) change in glycated hemoglobin (0.1% [-0.1, 0.2] for both SOC and evolocumab plus SOC) and fasting plasma glucose (0.06 mmol/L [-0.28, 0.38 mmol/L] for SOC and 0.06 mmol/L [-0.28, 0.44 mmol/L] for evolocumab plus SOC). Mean weight change (standard error) at 1 year was -0.1 kg (0.2) on SOC compared with 0.3 kg (0.1) on evolocumab plus SOC. The exposure-adjusted incidence rate (95% confidence intervals) for new-onset diabetes per 100 patient years was 3.7 (2.9 to 4.7) on control/SOC alone and 3.9 (3.2 to 4.6) on evolocumab/evolocumab plus SOC treatment. Glycemic changes observed in 6,430 participants at week 12 in the parent studies were comparable with OLE trial findings. In conclusion, evolocumab therapy has no effect on glucose homeostasis over 1 year of open-label treatment

    Conditional expression in corticothalamic efferents reveals a developmental role for nicotinic acetylcholine receptors in modulation of passive avoidance behavior

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    Prenatal nicotine exposure has been linked to attention deficit hyperactivity disorder and cognitive impairment, but the sites of action for these effects of nicotine are still under investigation. High-affinity nicotinic acetylcholine receptors (nAChRs) contain the .2 subunit and modulate passive avoidance (PA) learning in mice. Using an inducible, tetracycline-regulated transgenic system, we generated lines of mice with expression of high-affinity nicotinic receptors restored in specific neuronal populations. One line of mice shows functional .2 subunit-containing nAChRs localized exclusively in corticothalamic efferents. Functional, presynaptic nAChRs are present in the thalamus of these mice as detected by nicotine-elicited rubidium efflux assays from synaptosomes. Knock-out mice lacking high-affinity nAChRs show elevated baseline PA learning, whereas normal baseline PA behavior is restored in mice with corticothalamic expression of these nAChRs. In contrast, nicotine can enhance PA learning in adult wild-type animals but not in corticothalamic-expressing transgenic mice. When these transgenic mice are treated with doxycycline in adulthood to switch off nAChR expression, baseline PA is maintained even after transgene expression is abolished. These data suggest that high-affinity nAChRs expressed on corticothalamic neurons during development are critical for baseline PA performance and provide a potential neuroanatomical substrate for changes induced by prenatal nicotine exposure leading to long-term behavioral and cognitive deficits

    A Structural and Functional Comparison Between Infectious and Non-Infectious Autocatalytic Recombinant PrP Conformers

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    Infectious prions contain a self-propagating, misfolded conformer of the prion protein termed PrPSc. A critical prediction of the protein-only hypothesis is that autocatalytic PrPSc molecules should be infectious. However, some autocatalytic recombinant PrPSc molecules have low or undetectable levels of specific infectivity in bioassays, and the essential determinants of recombinant prion infectivity remain obscure. To identify structural and functional features specifically associated with infectivity, we compared the properties of two autocatalytic recombinant PrP conformers derived from the same original template, which differ by \u3e105-fold in specific infectivity for wild-type mice. Structurally, hydrogen/deuterium exchange mass spectrometry (DXMS) studies revealed that solvent accessibility profiles of infectious and non-infectious autocatalytic recombinant PrP conformers are remarkably similar throughout their protease-resistant cores, except for two domains encompassing residues 91-115 and 144-163. Raman spectroscopy and immunoprecipitation studies confirm that these domains adopt distinct conformations within infectious versus non-infectious autocatalytic recombinant PrP conformers. Functionally, in vitro prion propagation experiments show that the non-infectious conformer is unable to seed mouse PrPC substrates containing a glycosylphosphatidylinositol (GPI) anchor, including native PrPC. Taken together, these results indicate that having a conformation that can be specifically adopted by post-translationally modified PrPC molecules is an essential determinant of biological infectivity for recombinant prions, and suggest that this ability is associated with discrete features of PrPSc structure

    A Structural and Functional Comparison Between Infectious and Non-Infectious Autocatalytic Recombinant PrP Conformers

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    Infectious prions contain a self-propagating, misfolded conformer of the prion protein termed PrPSc. A critical prediction of the protein-only hypothesis is that autocatalytic PrPSc molecules should be infectious. However, some autocatalytic recombinant PrPSc molecules have low or undetectable levels of specific infectivity in bioassays, and the essential determinants of recombinant prion infectivity remain obscure. To identify structural and functional features specifically associated with infectivity, we compared the properties of two autocatalytic recombinant PrP conformers derived from the same original template, which differ by \u3e105-fold in specific infectivity for wild-type mice. Structurally, hydrogen/deuterium exchange mass spectrometry (DXMS) studies revealed that solvent accessibility profiles of infectious and non-infectious autocatalytic recombinant PrP conformers are remarkably similar throughout their protease-resistant cores, except for two domains encompassing residues 91-115 and 144-163. Raman spectroscopy and immunoprecipitation studies confirm that these domains adopt distinct conformations within infectious versus non-infectious autocatalytic recombinant PrP conformers. Functionally, in vitro prion propagation experiments show that the non-infectious conformer is unable to seed mouse PrPC substrates containing a glycosylphosphatidylinositol (GPI) anchor, including native PrPC. Taken together, these results indicate that having a conformation that can be specifically adopted by post-translationally modified PrPC molecules is an essential determinant of biological infectivity for recombinant prions, and suggest that this ability is associated with discrete features of PrPSc structure

    A 52-Week Placebo-Controlled Trial of Evolocumab in Hyperlipidemia

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    BACKGROUND Evolocumab, a monoclonal antibody that inhibits proprotein convertase subtilisin/ kexin type 9 (PCSK9), significantly reduced low-density lipoprotein (LDL) cholesterol levels in phase 2 studies. We conducted a phase 3 trial to evaluate the safety and efficacy of 52 weeks of treatment with evolocumab. METHODS We stratified patients with hyperlipidemia according to the risk categories outlined by the Adult Treatment Panel III of the National Cholesterol Education Program. On the basis of this classification, patients were started on background lipid-lowering therapy with diet alone or diet plus atorvastatin at a dose of 10 mg daily, atorvastatin at a dose of 80 mg daily, or atorvastatin at a dose of 80 mg daily plus ezetimibe at a dose of 10 mg daily, for a run-in period of 4 to 12 weeks. Patients with an LDL cholesterol level of 75 mg per deciliter (1.9 mmol per liter) or higher were then randomly assigned in a 2:1 ratio to receive either evolocumab (420 mg) or placebo every 4 weeks. The primary end point was the percent change from baseline in LDL cholesterol, as measured by means of ultracentrifugation, at week 52. RESULTS Among the 901 patients included in the primary analysis, the overall least-squares mean (±SE) reduction in LDL cholesterol from baseline in the evolocumab group, taking into account the change in the placebo group, was 57.0±2.1% (P<0.001). The mean reduction was 55.7±4.2% among patients who underwent background therapy with diet alone, 61.6±2.6% among those who received 10 mg of atorvastatin, 56.8±5.3% among those who received 80 mg of atorvastatin, and 48.5±5.2% among those who received a combination of 80 mg of atorvastatin and 10 mg of ezetimibe (P<0.001 for all comparisons). Evolocumab treatment also significantly reduced levels of apolipoprotein B, non-high-density lipoprotein cholesterol, lipoprotein(a), and triglycerides. The most common adverse events were nasopharyngitis, upper respiratory tract infection, influenza, and back pain. CONCLUSIONS At 52 weeks, evolocumab added to diet alone, to low-dose atorvastatin, or to high-dose atorvastatin with or without ezetimibe significantly reduced LDL cholesterol levels in patients with a range of cardiovascular risks

    Efficacy and Safety of Evolocumab in Reducing Lipids and Cardiovascular Events

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    BACKGROUND: Evolocumab, a monoclonal antibody that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9), significantly reduced low-density lipoprotein (LDL) cholesterol levels in short-term studies. We conducted two extension studies to obtain longer-term data. METHODS: In two open-label, randomized trials, we enrolled 4465 patients who had completed 1 of 12 phase 2 or 3 studies ("parent trials") of evolocumab. Regardless of study-group assignments in the parent trials, eligible patients were randomly assigned in a 2:1 ratio to receive either evolocumab (140 mg every 2 weeks or 420 mg monthly) plus standard therapy or standard therapy alone. Patients were followed for a median of 11.1 months with assessment of lipid levels, safety, and (as a prespecified exploratory analysis) adjudicated cardiovascular events including death, myocardial infarction, unstable angina, coronary revascularization, stroke, transient ischemic attack, and heart failure. Data from the two trials were combined. RESULTS: As compared with standard therapy alone, evolocumab reduced the level of LDL cholesterol by 61%, from a median of 120 mg per deciliter to 48 mg per deciliter (P<0.001). Most adverse events occurred with similar frequency in the two groups, although neurocognitive events were reported more frequently in the evolocumab group. The risk of adverse events, including neurocognitive events, did not vary significantly according to the achieved level of LDL cholesterol. The rate of cardiovascular events at 1 year was reduced from 2.18% in the standard-therapy group to 0.95% in the evolocumab group (hazard ratio in the evolocumab group, 0.47; 95% confidence interval, 0.28 to 0.78; P=0.003). CONCLUSIONS: During approximately 1 year of therapy, the use of evolocumab plus standard therapy, as compared with standard therapy alone, significantly reduced LDL cholesterol levels and reduced the incidence of cardiovascular events in a prespecified but exploratory analysis. (Funded by Amgen; OSLER-1 and OSLER-2 ClinicalTrials.gov numbers, NCT01439880 and NCT01854918.)
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