50 research outputs found

    Origin of the Local Bubble

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    We present a new unbiased search for OB associations in the Solar neighbourhood which have hosted the progenitor stars of the core collapse supernovae responsible for the Local Bubble in the interstellar gas. For this purpose we have analyzed a volume complete set (with a diameter of 400 pc) of B stars drawn from the Hipparcos catalogue and the Arivel data base, from which candidate members were selected by a kinematical criterion. After careful dereddening the star colours we have constructed a colour-magnitude diagram and confirmed that the Upper Scorpius, Upper Centaurus Lupus, and Lower Centaurus Crux subgroups of the Sco OB2 association are the youngest nearby OB associations. We dated their ages with theoretical isochrones in the range of 20–30 Myr, in agreement with previous work. We have traced backwards in time the paths of the stars and found that they entered the volume of the present bubble at 10 to 15 Myr ago. We argue that the Local Bubble began to form then and estimate that 14 to 20 supernovae have exploded since. The implied energy input into the ambient medium can be shown to be sufficient to excavate a bubble of the presently observed size

    The efficacy of immune checkpoint blockade for melanoma in-transit with or without nodal metastases – A multicenter cohort study

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    Purpose: Guidelines addressing melanoma in-transit metastasis (ITM) recommend immune checkpoint inhibitors (ICI) as a first-line treatment option, despite the fact that there are no efficacy data available from prospective trials for exclusively ITM disease. The study aims to analyze the outcome of patients with ITM treated with ICI based on data from a large cohort of patients treated at international referral clinics. Methods: A multicenter retrospective cohort study of patients treated between January 2015 and December 2020 from Australia, Europe, and the USA, evaluating treatment with ICI for ITM with or without nodal involvement (AJCC8 N1c, N2c, and N3c) and without distant disease (M0). Treatment was with PD-1 inhibitor (nivolumab or pembrolizumab) and/or CTLA-4 inhibitor (ipilimumab). The response was evaluated according to the RECIST criteria modified for cutaneous lesions. Results: A total of 287 patients from 21 institutions in eight countries were included. Immunotherapy was first-line treatment in 64 (22%) patients. PD-1 or CTLA-4 inhibitor monotherapy was given in 233 (81%) and 23 (8%) patients, respectively, while 31 (11%) received both in combination. The overall response rate was 56%, complete response (CR) rate was 36%, and progressive disease (PD) rate was 32%. Median PFS was ten months (95% CI 7.4e12.6 months) with a one-, two-, and five-year PFS rate of 48%, 33%, and 18%, respectively. Median MSS was not reached, and the one-, two-, and five-year MSS rates were 95%, 83%, and 71%, respectively. Conclusion: Systemic immunotherapy is an effective treatment for melanoma ITM. Future studies should evaluate the role of systemic immunotherapy in the context of multimodality therapy, including locoregional treatments such as surgery, intralesional therapy, and regional therapies.Carl-Jacob Holmberg ... Brendon Coventry ... Hidde Kroon ... et al

    von Willebrand disease investigated by two novel RFLPs.

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    Two partial cDNAs for von Willebrand factor (vWF) were used to investigate gene lesions and restriction fragment length polymorphisms (RFLPs) in vW disease (vWd) and normal controls. No gene alteration was detected but two TaqI RFLPs, likely to be intronic and originating from point mutations, were found in the 3' part of vWF gene. The two TaqI RFLPs, identified by the same probe, are informative in approximately 50% of the subjects. Used in combination with two other known RFLPs, they define several haplotypes similarly distributed in vWd and normals. Linkage disequilibrium between loci identified by the RFLPs is present. In a family study the RFLP patterns demonstrate homozygosity for the affected vWF gene in a severe (type III) patient and identify several heterozygous subjects. The RFLPs analysis has been related to the haemostatic values and multimer distribution. In two of the four unrelated patients with severe vWd examined the RFLPs study indicates double heterozygosity for the affected vWF genes

    Recent trends in the use of radical prostatectomy in England: the epidemiology of diffusion

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    OBJECTIVE To describe recent trends in the use of radical prostatectomy (RP) in England, as there is currently no consensus on the most effective treatment for localized prostate cancer, although RP is the treatment of choice among urological surgeons for men aged < 70 years. METHODS Routine data were assessed to establish the number of RPs performed in England in 1991–99. Age-standardized operation rates were compared by region and socio-economic group, and the geographical spread of use mapped. RESULTS The number of RPs performed annually increased nearly 20-fold between 1991 and 1999. Rates of surgery were greatest in the London National Health Service (NHS) regions and lowest in the Trent region. Outside London, the risk of surgery in a NHS hospital was significantly greater for men living in the least deprived areas; in London this trend was reversed. CONCLUSION Rapid increases in the use of RP showed marked regional variations, most likely related to access to prostate-specific antigen testing and the location of surgeons able to carry out radical surgery. By 1999, a third of procedures were still being undertaken in 'low-volume' hospitals, with implications for the quality of care and outcomes. Crucially, these developments occurred in the absence of robust information about the effectiveness of RP. Recent funding of a randomized trial of treatment options in this area is welcome, but wider questions remain about the timing of the evaluation of surgical technologies
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