| 1. |
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| 2. |
- Glasbey, JC, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 3. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 4. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 5. |
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| 6. |
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| 7. |
- Khatri, C, et al.
(författare)
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Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
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Tidskriftsartikel (refereegranskat)abstract
- Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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| 8. |
- Campbell, PJ, et al.
(författare)
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Pan-cancer analysis of whole genomes
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
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Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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| 9. |
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| 10. |
- O'Connor, C. M., et al.
(författare)
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Effect of nesiritide in patients with acute decompensated heart failure
- 2011
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Ingår i: The New England journal of medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 365:1, s. 32-43
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent. METHODS: We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days. RESULTS: Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P=0.03) and 24 hours (68.2% vs. 66.1%, P=0.007), but the prespecified level for significance (P
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| 11. |
- Eapen, Z. J., et al.
(författare)
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Do Countries or Hospitals With Longer Hospital Stays for Acute Heart Failure Have Lower Readmission Rates?: Findings From ASCEND-HF
- 2013
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Ingår i: Circulation Heart Failure. - 1941-3289 .- 1941-3297. ; 6:4, s. 727-32
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Tidskriftsartikel (refereegranskat)abstract
- Background- Hospital readmission is an important clinical outcome of patients with heart failure. Its relation to length of stay for the initial hospitalization is not clear. Methods and Results- We used hierarchical modeling of data from a clinical trial to examine variations in length of stay across countries and across hospitals in the United States and its association with readmission within 30 days of randomization. Main outcomes included associations between country-level length of stay and readmission rates, after adjustment for patient-level case mix; and associations between length of stay and readmission rates across sites in the United States. Across 27 countries with 389 sites and 6848 patients, mean length of stay ranged from 4.9 to 14.6 days (6.1 days in the United States). Rates of all-cause readmission ranged from 2.5% to 25.0% (17.8% in the United States). There was an inverse correlation between country-level mean length of stay and readmission (r=-0.52; P<0.01). After multivariable adjustment, each additional inpatient day across countries was associated with significantly lower risk of all-cause readmission (odds ratio, 0.86; 95% confidence interval, 0.75-0.98; P=0.02) and heart failure readmission (odds ratio, 0.79; 95% confidence interval, 0.69-0.99; P=0.03). Similar trends were observed across US study sites concerning readmission for any cause (odds ratio, 0.92; 95% confidence interval, 0.85-1.00; P=0.06) and readmission for heart failure (odds ratio, 0.90; 95% confidence interval, 0.80-1.01; P=0.07). Across countries and across US sites, longer median length of stay was independently associated with lower risk of readmission. Conclusions- Countries with longer length of stay for heart failure hospitalizations had significantly lower rates of readmission within 30 days of randomization. These findings may have implications for developing strategies to prevent readmission, defining quality measures, and designing clinical trials in acute heart failure. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.
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| 12. |
- Gordon, I.E., et al.
(författare)
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The HITRAN2020 molecular spectroscopic database
- 2022
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Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - : Elsevier. - 0022-4073 .- 1879-1352. ; 277
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Tidskriftsartikel (refereegranskat)abstract
- The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition.
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| 13. |
- Hernandez, A. F., et al.
(författare)
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Rationale and design of the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure Trial (ASCEND-HF)
- 2009
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Ingår i: Am Heart J. - 1097-6744. ; 157:2, s. 271-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Acute decompensated heart failure (ADHF) is a major public health burden with significant mortality and morbidity. Nesiritide is a recombinantly produced intravenous formulation of human B-type natriuretic peptide that promotes vasodilation and increases salt and water excretion, which results in reduced cardiac filling pressures. Prior studies have shown that dyspnea is improved in patients with ADHF 3 hours after nesiritide infusion with significant dose-related reductions in cardiac filling pressures and systemic vascular resistance without significant arrhythmias. However, the effect of nesiritide on dyspnea at 6 or 24 hours is unknown, and no clinical outcome trials have been done to provide a reliable estimate of the effect of nesiritide on morbidity and mortality. METHODS: The Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure trial (ASCEND-HF) is a phase III study evaluating the efficacy and safety of nesiritide in patients with ADHF. Patients hospitalized for hear failure will be randomly assigned to receive either intravenous nesiritide or matching placebo for 24 hours to 7 days. The 2 coprimary end points are (1) assessment of acute dyspnea at 6 or 24 hours and (2) death or rehospitalization for hear failure within 30 days. A total of 7,000 patients will be enrolled worldwide between 2007 and 2010. CONCLUSIONS: The data from the ASCEND-HF trial will establish whether nesiritide safely improves acute dyspnea as well as morbidity and mortality at 30 days.
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| 14. |
- Asim, M, et al.
(författare)
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Synthetic lethality between androgen receptor signalling and the PARP pathway in prostate cancer
- 2017
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8:1, s. 374-
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Tidskriftsartikel (refereegranskat)abstract
- Emerging data demonstrate homologous recombination (HR) defects in castration-resistant prostate cancers, rendering these tumours sensitive to PARP inhibition. Here we demonstrate a direct requirement for the androgen receptor (AR) to maintain HR gene expression and HR activity in prostate cancer. We show that PARP-mediated repair pathways are upregulated in prostate cancer following androgen-deprivation therapy (ADT). Furthermore, upregulation of PARP activity is essential for the survival of prostate cancer cells and we demonstrate a synthetic lethality between ADT and PARP inhibition in vivo. Our data suggest that ADT can functionally impair HR prior to the development of castration resistance and that, this potentially could be exploited therapeutically using PARP inhibitors in combination with androgen-deprivation therapy upfront in advanced or high-risk prostate cancer.
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| 15. |
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| 16. |
- Berry, C, et al.
(författare)
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The survival of patients with heart failure with preserved or reduced left ventricular ejection fraction: an individual patient data meta-analysis.
- 2012
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Ingår i: European heart journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 33:14, s. 1750-7
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Tidskriftsartikel (refereegranskat)abstract
- A substantial proportion of patients with heart failure have preserved left ventricular ejection fraction (HF-PEF). Previous studies have reported mixed results whether survival is similar to those patients with heart failure and reduced EF (HF-REF).We compared survival in patients with HF-PEF with that in patients with HF-REF in a meta-analysis using individual patient data. Preserved EF was defined as an EF ≥ 50%. The 31 studies included 41 972 patients: 10 347 with HF-PEF and 31 625 with HF-REF. Compared with patients with HF-REF, those with HF-PEF were older (mean age 71 vs. 66 years), were more often women (50 vs. 28%), and have a history of hypertension (51 vs. 41%). Ischaemic aetiology was less common (43 vs. 59%) in patients with HF-PEF. There were 121 [95% confidence interval (CI): 117, 126] deaths per 1000 patient-years in those with HF-PEF and 141 (95% CI: 138, 144) deaths per 1000 patient-years in those with HF-REF. Patients with HF-PEF had lower mortality than those with HF-REF (adjusted for age, gender, aetiology, and history of hypertension, diabetes, and atrial fibrillation); hazard ratio 0.68 (95% CI: 0.64, 0.71). The risk of death did not increase notably until EF fell below 40%.Patients with HF-PEF have a lower risk of death than patients with HF-REF, and this difference is seen regardless of age, gender, and aetiology of HF. However, absolute mortality is still high in patients with HF-PEF highlighting the need for a treatment to improve prognosis.
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| 17. |
- Packer, M., et al.
(författare)
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Long-Term Effect of Endothelin Receptor Antagonism With Bosentan on the Morbidity and Mortality of Patients With Severe Chronic Heart Failure Primary Results of the ENABLE Trials
- 2017
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Ingår i: Jacc-Heart Failure. - : Elsevier BV. - 2213-1779. ; 5:5, s. 317-326
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES The objective of this clinical trial was to evaluate the long-term effect of endothelin receptor antagonism with bosentan on the morbidity and mortality of patients with severe chronic heart failure. BACKGROUND Endothelin may play a role in heart failure, but short-term clinical trials with endothelin receptor antagonists have reported disappointing results. Long-term trials are lacking. METHODS In 2 identical double-blind trials, we randomly assigned 1,613 patients with New York Heart Association functional class Illb to IV heart failure and an ejection fraction < 35% to receive placebo or bosentan (target dose 125 mg twice daily) for a median of 1.5 years. The primary outcome for each trial was clinical status at 9 months (assessed by the hierarchical clinical composite); the primary outcome across the 2 trials was death from any cause or hospitalization for heart failure. RESULTS Bosentan did not influence clinical status at 9 months in either trial (p = 0.928 and p = 0.263). In addition, 321 patients in the placebo group and 312 patients in the bosentan group died or were hospitalized for heart failure (hazard ratio [HR]: 1.01; 95% confidence interval [CI]: 0.86 to 1.18; p = 0.90). The bosentan group experienced fluid retention within the first 2 to 4 weeks, as evidenced by increased peripheral edema, weight gain, decreases in hemoglobin, and an increased risk of hospitalization for heart failure, despite intensification of background diuretics. During follow-up, 173 patients died in the placebo group and 160 patients died in the bosentan group (HR: 0.94; 95% CI: 0.75 to 1.16). About 10% of the bosentan group showed meaningful increases in hepatic transaminases, but none had acute or chronic liver failure. CONCLUSIONS Bosentan did not improve the clinical course or natural history of patients with severe chronic heart failure and but caused early and important fluid retention. (J Am Coll Cardiol HF 2017;5:317-26) (C) 2017 by the American College of Cardiology Foundation.
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| 18. |
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| 19. |
- Toma, M., et al.
(författare)
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The relationship between left ventricular ejection fraction and mortality in patients with acute heart failure: insights from the ASCEND-HF Trial
- 2014
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Ingår i: European Journal of Heart Failure. - : Wiley. - 1388-9842. ; 16:3, s. 334-41
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Tidskriftsartikel (refereegranskat)abstract
- AIM: Acute decompensated heart failure (ADHF) is associated with significant morbidity and mortality but the relationship between LVEF and outcomes is unclear. We explored the association between LVEF and 30 and 180 day mortality in 7007 ADHF patients enrolled in the Acute Studies of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial. METHODS AND RESULTS: We explored the association between LVEF and 30 and 180 day mortality in 7007 ADHF patients enrolled in the Acute Studies of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial. LVEF was analysed both as a continuous variable and according to three categories: < 40% (LowEF), 40-50% [intermediate EF (IntEF)], and > 50% [preserved ejection fraction (PresEF)]. Of the patients in the trial, 4474 (78.7%) had LowEF, 674 (11.9%) had IntEF, and 539 (9.5%) had PresEF. The unadjusted 30 and 180 day mortality was similar for LowEF (3.7%, 12.3%), IntEF (3.4%, 13.1%), and PresEF (4.3%, 14.1%), respectively (P > 0.05). After multivariable adjustment, the hazard ratio (HR) for 180 day mortality remained similar for the LowEF [HR 0.96, 95% confidence interval (CI) 0.75-1.24; P = 0.77] and IntEF (0.91, 95% CI 0.66-1.3; P = 0.58) compared to PresEF patients. By contrast, when LVEF was evaluated as a continuous measure, it exhibited a U-shaped pattern with mortality. After matching for age and sex, the mortality risk attributed to LVEF was attenuated, as the LVEF increased as a continuous variable over 35%. However, in patients with EF < 35%, the mortality risk continue to increase as the LVEF declined. CONCLUSIONS: Among patients with ADHF, the unadjusted mortality rates are similar across LVEF strata. However, after accounting for key patient variables, the mortality risk increases as EF falls below 35%. These data will be useful in planning future studies of ADHF. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifier: NCT00475852.
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| 20. |
- Benatar, Michael, et al.
(författare)
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Safety and efficacy of arimoclomol in patients with early amyotrophic lateral sclerosis (ORARIALS-01) : a randomised, double-blind, placebo-controlled, multicentre, phase 3 trial
- 2024
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Ingår i: Lancet Neurology. - : Elsevier. - 1474-4422 .- 1474-4465. ; 23:7, s. 687-699
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Tidskriftsartikel (refereegranskat)abstract
- Background: Amyotrophic lateral sclerosis is a progressive neurodegenerative disorder leading to muscle weakness and respiratory failure. Arimoclomol, a heat-shock protein-70 (HSP70) co-inducer, is neuroprotective in animal models of amyotrophic lateral sclerosis, with multiple mechanisms of action, including clearance of protein aggregates, a pathological hallmark of sporadic and familial amyotrophic lateral sclerosis. We aimed to evaluate the safety and efficacy of arimoclomol in patients with amyotrophic lateral sclerosis.Methods: ORARIALS-01 was a multinational, randomised, double-blind, placebo-controlled, parallel-group trial done at 29 centres in 12 countries in Europe and North America. Patients were eligible if they were aged 18 years or older and met El Escorial criteria for clinically possible, probable, probable laboratory-supported, definite, or familial amyotrophic lateral sclerosis; had an ALS Functional Rating Scale-Revised score of 35 or more; and had slow vital capacity at 70% or more of the value predicted on the basis of the participant's age, height, and sex. Patients were randomly assigned (2:1) in blocks of 6, stratified by use of a stable dose of riluzole or no riluzole use, to receive oral arimoclomol citrate 1200 mg/day (400 mg three times per day) or placebo. The Randomisation sequence was computer generated centrally. Investigators, study personnel, and study participants were masked to treatment allocation. The primary outcome was the Combined Assessment of Function and Survival (CAFS) rank score over 76 weeks of treatment. The primary outcome and safety were analysed in the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03491462, and is completed.Findings: Between July 31, 2018, and July 17, 2019, 287 patients were screened, 245 of whom were enrolled in the trial and randomly assigned. The modified intention-to-treat population comprised 239 patients (160 in the arimoclomol group and 79 in the placebo group): 151 (63%) were male and 88 (37%) were female; mean age was 57·6 years (SD 10·9). CAFS score over 76 weeks did not differ between groups (mean 0·51 [SD 0·29] in the arimoclomol group vs 0·49 [0·28] in the placebo group; p=0·62). Cliff's delta comparing the two groups was 0·039 (95% CI –0·116 to 0·194). Proportions of participants who died were similar between the treatment groups: 29 (18%) of 160 patients in the arimoclomol group and 18 (23%) of 79 patients in the placebo group. Most deaths were due to disease progression. The most common adverse events were gastrointestinal. Adverse events were more often deemed treatment-related in the arimoclomol group (104 [65%]) than in the placebo group (41 [52%]) and more often led to treatment discontinuation in the arimoclomol group (26 [16%]) than in the placebo group (four [5%]).Interpretation: Arimoclomol did not improve efficacy outcomes compared with placebo. Although available biomarker data are insufficient to preclude future strategies that target the HSP response, safety data suggest that a higher dose of arimoclomol would not have been tolerated.Funding: Orphazyme.
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| 21. |
- Denler, Melissa C., et al.
(författare)
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Mn IV -Oxo complex of a bis(benzimidazolyl)-containing N5 ligand reveals different reactivity trends for Mn IV -oxo than Fe IV -oxo species
- 2019
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 48:15, s. 5007-5021
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Tidskriftsartikel (refereegranskat)abstract
- Using the pentadentate ligand (N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, 2pyN2B), presenting two pyridyl and two (N-methyl)benzimidazolyl donor moieties in addition to a central tertiary amine, new Mn II and Mn IV -oxo complexes were generated and characterized. The [Mn IV (O)(2pyN2B)] 2+ complex showed spectroscopic signatures (i.e., electronic absorption band maxima and intensities, EPR signals, and Mn K-edge X-ray absorption edge and near-edge data) similar to those observed for other Mn IV -oxo complexes with neutral, pentadentate N 5 supporting ligands. The near-IR electronic absorption band maximum of [Mn IV (O)(2pyN2B)] 2+ , as well as DFT-computed metric parameters, are consistent with the equatorial (N-methyl)benzimidazolyl ligands being stronger donors to the Mn IV center than the pyridyl and quinolinyl ligands found in analogous Mn IV -oxo complexes. The hydrogen- and oxygen-atom transfer reactivities of [Mn IV (O)(2pyN2B)] 2+ were assessed through reactions with hydrocarbons and thioanisole, respectively. When compared with related Mn IV -oxo adducts, [Mn IV (O)(2pyN2B)] 2+ showed muted reactivity in hydrogen-atom transfer reactions with hydrocarbons. This result stands in contrast to observations for the analogous Fe IV -oxo complexes, where [Fe IV (O)(2pyN2B)] 2+ was found to be one of the more reactive members of its class.
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| 22. |
- Massie, Allyssa A., et al.
(författare)
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Equatorial Ligand Perturbations Influence the Reactivity of Manganese(IV)-Oxo Complexes
- 2017
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Ingår i: Angewandte Chemie (International edition). - : Wiley. - 1433-7851. ; 56:15, s. 4178-4182
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Tidskriftsartikel (refereegranskat)abstract
- Manganese(IV)-oxo complexes are often invoked as intermediates in Mn-catalyzed C-H bond activation reactions. While many synthetic MnIV-oxo species are mild oxidants, other members of this class can attack strong C-H bonds. The basis for these reactivity differences is not well understood. Here we describe a series of MnIV-oxo complexes with N5 pentadentate ligands that modulate the equatorial ligand field of the MnIV center, as assessed by electronic absorption, electron paramagnetic resonance, and Mn K-edge X-ray absorption methods. Kinetic experiments show dramatic rate variations in hydrogen-atom and oxygen-atom transfer reactions, with faster rates corresponding to weaker equatorial ligand fields. For these MnIV-oxo complexes, the rate enhancements are correlated with both 1)the energy of a low-lying 4E excited state, which has been postulated to be involved in a two-state reactivity model, and 2)the MnIII/IV reduction potentials.
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| 23. |
- Massie, Allyssa A., et al.
(författare)
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Structural Characterization of a Series of N5-Ligated MnIV-Oxo Species
- 2020
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 26:4, s. 900-912
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of extended X-ray absorption fine structure (EXAFS) data for the MnIV-oxo complexes [MnIV(O)(DMMN4py)]2+, [MnIV(O)(2pyN2B)]2+, and [MnIV(O)(2pyN2Q)]2+ (DMMN4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [MnIV(O)(DMMN4py)]2+ and [MnIV(O)(2pyN2B)]2+ are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [MnIV(O)(2pyN2Q)]2+ was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [MnIV(O)(2pyN2Q)]2+. The Mn=O distances for [MnIV(O)(DMMN4py)]2+ and [MnIV(O)(2pyN2B)]2+ could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing MnIV-oxo adducts. The DFT methods were extended to investigate the structure of the putative [MnIV(O)(N4py)]2+⋅(HOTf)2 adduct. These computations suggest that a MnIV-hydroxo species is most consistent with the available experimental data.
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| 24. |
- Massie, Barry M, et al.
(författare)
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Rolofylline, an adenosine A1-receptor antagonist, in acute heart failure.
- 2010
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Ingår i: The New England journal of medicine. - 1533-4406. ; 363:15, s. 1419-28
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Tidskriftsartikel (refereegranskat)abstract
- Worsening renal function, which is associated with adverse outcomes, often develops in patients with acute heart failure. Experimental and clinical studies suggest that counterregulatory responses mediated by adenosine may be involved. We tested the hypothesis that the use of rolofylline, an adenosine A1-receptor antagonist, would improve dyspnea, reduce the risk of worsening renal function, and lead to a more favorable clinical course in patients with acute heart failure.
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| 25. |
- Singh, Priya, et al.
(författare)
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C-H Bond Oxidation by MnIV-Oxo Complexes : Hydrogen-Atom Tunneling and Multistate Reactivity
- 2024
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Ingår i: Inorganic Chemistry. - 0020-1669.
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Tidskriftsartikel (refereegranskat)abstract
- The reactivity of six MnIV-oxo complexes in C-H bond oxidation has been examined using a combination of kinetic experiments and computational methods. Variable-temperature studies of the oxidation of 9,10-dihydroanthracene (DHA) and ethylbenzene by these MnIV-oxo complexes yielded activation parameters suitable for evaluating electronic structure computations. Complementary kinetic experiments of the oxidation of deuterated DHA provided evidence for hydrogen-atom tunneling in C-H bond oxidation for all MnIV-oxo complexes. These results are in accordance with the Bell model, where tunneling occurs near the top of the transition-state barrier. Density functional theory (DFT) and DLPNO-CCSD(T1) computations were performed for three of the six MnIV-oxo complexes to probe a previously predicted multistate reactivity model. The DFT computations predicted a thermal crossing from the 4B1 ground state to a 4E state along the C-H bond oxidation reaction coordinate. DLPNO-CCSD(T1) calculations further confirm that the 4E transition state offers a lower energy barrier, reinforcing the multistate reactivity model for these complexes. We discuss how this multistate model can be reconciled with recent computations that revealed that the kinetics of C-H bond oxidation by this set of MnIV-oxo complexes can be well-predicted on the basis of the thermodynamic driving force for these reactions.
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