Supernovae are thought to arise from two different physical processes. The cores of massive, short-lived stars undergo gravitational core collapse and typically eject a few solar masses during their ...explosion. These are thought to appear as type Ib/c and type II supernovae, and are associated with young stellar populations. In contrast, the thermonuclear detonation of a carbon-oxygen white dwarf, whose mass approaches the Chandrasekhar limit, is thought to produce type Ia supernovae. Such supernovae are observed in both young and old stellar environments. Here we report a faint type Ib supernova, SN 2005E, in the halo of the nearby isolated galaxy, NGC 1032. The ‘old’ environment near the supernova location, and the very low derived ejected mass (∼0.3 solar masses), argue strongly against a core-collapse origin. Spectroscopic observations and analysis reveal high ejecta velocities, dominated by helium-burning products, probably excluding this as a subluminous or a regular type Ia supernova. We conclude that it arises from a low-mass, old progenitor, likely to have been a helium-accreting white dwarf in a binary. The ejecta contain more calcium than observed in other types of supernovae and probably large amounts of radioactive 44Ti.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract only
2007
Background: Age is the most important therapy-independent prognostic factor in patients with primary central nervous system lymphoma (PCNSL). Here we aimed at providing an analysis ...of the impact of higher age on response to therapy, toxicity, and survival in the largest PCNSL trial ever performed to date. Methods: Response to therapy, toxicity and survival of PCNSL patients enrolled in the G-PCNSL-SG-1 trial evaluating the role of radiotherapy after high-dose methotrexate (HD-MTX)-based chemotherapy were monitored. Subjects aged 70 or more were compared to younger patients. Results: Of all eligible patients (n=526), 126 (24%) were aged 70 or more. In the per protocol population, 66 of 318 patients (21%) were at least 70 years old. Among the eligible patients, the rate of complete and partial responses (CR+PR) to HD-MTX-based chemotherapy was 44% in the elderly compared to 57% in the younger patients (p=0.016). A higher rate of grade III/IV leukopenia was observed in the elderly (34% versus 21%, p=0.007). Also, death on therapy was more frequent (18% versus 11%; p=0.027) in these patients. In contrast, there was no other major age-dependent toxicity. Survival analyses revealed shorter progression-free survival (PFS) (4.0 versus 7.7 months, p=0.014) and overall survival (OS) (12.5 versus 26.2 months, p<0.001) in the elderly population. The PFS of CR patients was 35.0 months in younger patients compared to 16.1 in the elderly (p=0.024). Salvage therapy was used less commonly in elderly patients. When salvage WBRT was applied in patients who had failed on HD-MTX-based chemotherapy, there was no association between age and survival (p=0.633). Conclusions: Elderly PCNSL patients have a lower response rate and higher mortality on HD-MTX-based chemotherapy. Their PFS is shorter and they receive less salvage therapy which may contribute to the poor prognosis.
Abstract only
2015
Background: Fluorine-18-labeled (
18
F) fluorodeoxyglucose (FDG) positron emission tomography (PET) has demonstrated remarkable sensitivity in the detection and follow-up of ...malignant lymphoma. The aim of this study was the prospective evaluation of potential benefits of FDG-PET including whole-body PET for evaluation of disease extent, response to treatment and follow-up of patients with primary CNS lymphoma (PCNSL). Methods: Extent of disease and response to therapy were evaluated using homologous scans of MR imaging and a total number of 36
18
F-FDG-PET examinations in 10 immunocompetent patients with newly diagnosed or recurrent PCNSL before and repeatedly during treatment and follow-up. Results: In 4 of 10 patients before treatment, MRI findings lacked a PET correlative, and in two patients each one additional lesion not visualized by MRI was detected by PET. Additional systemic spots of activity in whole-body PET were found in two patients and confirmed as asymptomatic lymphoma manifestations by computed tomography (CT) in one patient. Under treatment, tumor response was congruent on PET and MRI in 4 of 6 patients. In two patients, however, PET indicated complete disappearance of vital tumor while findings persisted on MRI. During follow-up in a series of 5 patients, pathologic FDG-uptake had been found in one patient on PET 34 weeks after therapy and 9 weeks before relapse was diagnosed on MRI. In another patient, relapse was suspected on PET 76 weeks after therapy without a correlative on MRI performed 2 and 6 weeks thereafter. Conclusions: In PCNSL, FDG-PET may contribute additional information regarding the extent of disease and response to treatment. Relapse can probably be detected earlier than with MRI.
No significant financial relationships to disclose.
A Georgian Woman With Dysphagia and Stridor Kiewe, Philipp, MD; Hammersen, Stefanie, MD; Schneider, Thomas, MD
Gastroenterology (New York, N.Y. 1943)
138, Številka:
2
Journal Article
Supernovae (SNe) are thought to arise from two different physical processes. The cores of massive, short-lived stars undergo gravitational core collapse and typically eject a few solar masses during ...their explosion. These are thought to appear as as type Ib/c and II SNe, and are associated with young stellar populations. A type Ia SN is thought to arise from the thermonuclear detonation of a white dwarf star composed mainly of carbon and oxygen, whose mass approaches the Chandrasekhar limit. Such SNe are observed in both young and old stellar environments. Here we report our discovery of the faint type Ib SN 2005E in the halo of the nearby isolated galaxy, NGC 1032. The lack of any trace of recent star formation near the SN location (Fig. 1), and the very low derived ejected mass (~0.3 M_sun), argue strongly against a core-collapse origin for this event. Spectroscopic observations and the derived nucleosynthetic output show that the SN ejecta have high velocities and are dominated by helium-burning products, indicating that SN 2005E was neither a subluminous nor a regular SN Ia (Fig. 2). We have therefore found a new type of stellar explosion, arising from a low-mass, old stellar system, likely involving a binary with a primary white dwarf and a helium-rich secondary. The SN ejecta contain more calcium than observed in any known type of SN and likely additional large amounts of radioactive 44Ti. Such SNe may thus help resolve fundamental physical puzzles, extending from the composition of the primitive solar system and that of the oldest stars, to the Galactic production of positrons.
We present R-band light curves of Type II supernovae (SNe) from the Caltech Core-Collapse Project (CCCP). With the exception of interacting (Type IIn) SNe and rare events with long rise times, we ...find that most light curve shapes belong to one of three apparently distinct classes: plateau, slowly declining, and rapidly declining events. The last class is composed solely of Type IIb SNe which present similar light curve shapes to those of SNe Ib, suggesting, perhaps, similar progenitor channels. We do not find any intermediate light curves, implying that these subclasses are unlikely to reflect variance of continuous parameters, but rather might result from physically distinct progenitor systems, strengthening the suggestion of a binary origin for at least some stripped SNe. We find a large plateau luminosity range for SNe IIP, while the plateau lengths seem rather uniform at approximately 100 days. As analysis of additional CCCP data goes on and larger samples are collected, demographic studies of core-collapse SNe will likely continue to provide new constraints on progenitor scenarios.
Myelodysplastic syndromes are characterised by ineffective erythropoiesis. Luspatercept (ACE-536) is a novel fusion protein that blocks transforming growth factor beta (TGF β) superfamily inhibitors ...of erythropoiesis, giving rise to a promising new investigative therapy. We aimed to assess the safety and efficacy of luspatercept in patients with anaemia due to lower-risk myelodysplastic syndromes.
In this phase 2, multicentre, open-label, dose-finding study (PACE-MDS), with long-term extension, eligible patients were aged 18 years or older, had International Prognostic Scoring System-defined low or intermediate 1 risk myelodysplastic syndromes or non-proliferative chronic myelomonocytic leukaemia (white blood cell count <13 000/μL), and had anaemia with or without red blood cell transfusion support. Enrolled patients were classified as having low transfusion burden, defined as requiring less than 4 red blood cell units in the 8 weeks before treatment (and baseline haemoglobin <10 g/dL), or high transfusion burden, defined as requiring 4 or more red blood cell units in the 8 weeks before treatment. Patients received luspatercept subcutaneously once every 21 days at dose concentrations ranging from 0·125 mg/kg to 1·75 mg/kg bodyweight for five doses (over a maximum of 12 weeks). Patients in the expansion cohort were treated with 1·0 mg/kg luspatercept; dose titration up to 1·75 mg/kg was allowed, and patients could be treated with luspatercept for a maximum of 5 years. Patients in the base study were assessed for response and safety after 12 weeks in order to be considered for enrolment into the extension study. The primary endpoint was the proportion of patients achieving modified International Working Group-defined haematological improvement–erythroid (HI-E), defined as a haemoglobin concentration increase of 1·5 g/dL or higher from baseline for 14 days or longer in low transfusion burden patients, and a reduction in red blood cell transfusion of 4 or more red blood cell units or a 50% or higher reduction in red blood cell units over 8 weeks versus pre-treatment transfusion burden in high transfusion burden patients. Patient data were subcategorised by: luspatercept dose concentrations (0·125–0·5 mg/kg vs 0·75–1·75 mg/kg); pre-study transfusion burden (high transfusion burden vs low transfusion burden, defined as ≥4 vs <4 red blood cell units per 8 weeks); pre-study serum erythropoietin concentration (<200 IU/L, 200–500 IU/L, and >500 IU/L); presence of 15% or more ring sideroblasts; and presence of SF3B1 mutations. Efficacy analyses were carried out on the efficacy evaluable and intention-to-treat populations. This trial is currently ongoing. This study is registered with ClinicalTrials.gov, numbers NCT01749514 and NCT02268383.
Between Jan 21, 2013, and Feb 12, 2015, 58 patients with myelodysplastic syndromes were enrolled in the 12 week base study at nine treatment centres in Germany; 27 patients were enrolled in the dose-escalation cohorts (0·125–1·75 mg/kg) and 31 patients in the expansion cohort (1·0–1·75 mg/kg). 32 (63% 95% CI 48–76) of 51 patients receiving higher dose luspatercept concentrations (0·75–1·75 mg/kg) achieved HI-E versus two (22% 95% CI 3–60) of nine receiving lower dose concentrations (0·125–0·5 mg/kg). Three treatment-related grade 3 adverse events occurred in one patient each: myalgia (one 2%), increased blast cell count (one 2%), and general physical health deterioration (one 2%). Two of these treatment-related grade 3 adverse events were reversible serious grade 3 adverse events: one patient (2%) had myalgia and one patient (2%) had general physical health deterioration.
Luspatercept was well tolerated and effective for the treatment of anaemia in lower-risk myelodysplastic syndromes and so could therefore provide a novel therapeutic approach for the treatment of anaemia associated with lower-risk myelodysplastic syndromes; further studies are ongoing.
Acceleron Pharma.
Type IIn supernovae (SNe IIn) are rare events, constituting only a few percent of all core-collapse SNe, and the current sample of well-observed SNe IIn is small. Here, we study the four SNe IIn ...observed by the Caltech Core-Collapse Project (CCCP). The CCCP SN sample is unbiased to the extent that object selection was not influenced by target SN properties. Therefore, these events are representative of the observed population of SNe IIn. We find that a narrow P-Cygni profile in the hydrogen Balmer lines appears to be a ubiquitous feature of SNe IIn. Our light curves show a relatively long rise time (>20 days) followed by a slow decline stage (0.01-0.15 mag day--1), and a typical V-band peak magnitude of MV = --18.4 ? 1.0 mag. We measure the progenitor star wind velocities (600-1400 km s--1) for the SNe in our sample and derive pre-explosion mass-loss rates (0.026-0.12 M yr--1). We compile similar data for SNe IIn from the literature and discuss our results in the context of this larger sample. Our results indicate that typical SNe IIn arise from progenitor stars that undergo luminous-blue-variable-like mass loss shortly before they explode.
To assess the outcome of elderly patients with primary CNS lymphoma (PCNSL) treated within the G-PCNSL-SG-1 trial.
We reviewed response, toxicity, and survival of patients with PCNSL aged 70 or more ...enrolled in the G-PCNSL-SG-1 trial.
A total of 126 of the 526 eligible patients (24%) and 66 of 318 patients (21%) in the per protocol population were aged 70 or more. Among all eligible patients, the rate of complete and partial responses (CR+PR) to HD-MTX-based chemotherapy was 44% in the elderly vs 57% in the younger patients (p = 0.016). Toxicity was age-independent except for a higher rate of grade III/IV leukopenia in the elderly (34% vs 21%, p = 0.007). Death on therapy was more frequent (18% vs 11%; p = 0.027), and progression-free survival (PFS) (4.0 vs 7.7 months, p = 0.014) and overall survival (12.5 vs 26.2 months, p < 0.001) inferior, in the elderly. A striking difference between younger and elderly patients was the PFS of CR patients of 35.0 in the younger vs 16.1 in the elderly patients (p = 0.024). Elderly patients were treated less often and less aggressively at salvage. However, age was not associated with survival from salvage whole brain radiotherapy in patients progressing during primary HD-MTX-based chemotherapy (p = 0.633).
Lower response rate and higher mortality on HD-MTX-based chemotherapy as well as lower PFS of CR patients and less salvage therapy contribute to the poor prognosis of elderly patients with PCNSL.
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