174 research outputs found
A semi-coherent generalization of the 5-vector method to search for continuous gravitational waves
The emission of continuous gravitational waves (CWs), with duration much
longer than the typical data taking runs, is expected from several sources,
notably spinning neutron stars, asymmetric with respect to their rotation axis
and more exotic sources, like ultra-light scalar boson clouds formed around
Kerr black holes and sub-solar mass primordial binary black holes. Unless the
signal time evolution is well predicted and its relevant parameters accurately
known, the search for CWs is typically based on semi-coherent methods, where
the full data set is divided in shorter chunks of given duration, which are
properly processed, and then incoherently combined. In this paper we present a
semi-coherent method, in which the so-called \textit{5-vector} statistics is
computed for the various data segments and then summed after the removal of the
Earth Doppler modulation and signal intrinsic spin-down. The method can work
with segment duration of several days, thanks to a double stage procedure in
which an initial rough correction of the Doppler and spin-down is followed by a
refined step in which the residual variations are removed. This method can be
efficiently applied for directed searches, where the source position is known
to a good level of accuracy, and in the candidate follow-up stage of
wide-parameter space searches.Comment: 16 pages, 12 figure
Mechanism of inhibition of cytochrome P450 C21 enzyme activity by autoantibodies from patients with Addison's disease
Objective: To study possible mechanisms for the inhibition of cytochrome P450 C21 (steroid 21-hydroxylase) enzyme activity by P450 C21 autoantibodies (Abs)in vitro.Design: Two possible mechanisms for the inhibition of P450 C21 enzyme activity by P450 C21 Abs were studied: (a) conformational changes in the P450 C21 molecule induced by Ab binding and (b) the effects of Ab binding to P450 C21 on the electron transfer from the nicotinamide adenine dinucleotide phosphate reduced (NADPH) cytochrome P450 reductase (CPR) to P450 C21.Methods: The effect of P450 C21 Ab binding on the conformation of recombinant P450 C21 in yeast microsomes was studied using an analysis of the dithionite-reduced CO difference spectra. The effect of P450 C21 Abs on electron transfer was assessed by analysis of reduction of P450 C21 in the microsomes in the presence of CO after addition of NADPH.Results: Our studies confirmed the inhibiting effect of P450 C21 Abs on P450 C21 enzyme activity. Binding of the Abs did not induce significant change in the P450 C21 peak at 450 nm (native form) and did not produce a detectable peak at 420 nm (denatured form) in the dithionite-reduced CO difference spectra. This indicated that conformation of P450 C21 around the heme was not altered compared with the native structure. However, incubation of the P450 C21 in yeast microsomes with P450 C21 Ab inhibited the fast phase electron transfer from the CPR to P450 C21.Conclusions: Our observations suggested that the mechanism by which P450 C21 Abs inhibit P450 C21 enzyme activity most likely involves inhibition of the interaction between the CPR and P450 C21
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Validation of the Decipher Genomic Classifier in Patients receiving Salvage Radiotherapy without Hormone Therapy after Radical Prostatectomy - An Ancillary Study of the SAKK 09/10 Randomized Clinical Trial.
BACKGROUND
The Decipher genomic classifier (GC) has shown to independently prognosticate outcomes in prostate cancer. The objective of this study was to validate the GC in a randomized phase 3 trial of dose-escalated salvage radiotherapy (SRT) after radical prostatectomy.
PATIENTS AND METHODS
A clinical grade whole-transcriptome assay was performed on RP samples obtained from patients enrolled in SAKK 09/10, a phase 3 trial of 350 men with biochemical recurrence post-radical prostatectomy randomized to 64Gy vs. 70Gy without concurrent hormonal therapy or pelvic nodal radiotherapy (RT). A pre-specified statistical plan was developed to assess the impact of the GC on clinical outcomes. The primary endpoint was biochemical progression; secondary endpoints were clinical progression and time to hormone therapy. Multivariable analyses adjusted for age, T-category, Gleason score, post-radical prostatectomy persistent prostate-specific antigen (PSA), PSA at randomization, and randomization arm were conducted, accounting for competing risks.
RESULTS
The analytic cohort of 226 patients was representative of the overall trial, with median follow-up of 6.3 years (IQR 6.1-7.2). GC (high vs. low-intermediate) was independently associated with biochemical progression (subdistribution hazard ratio [sHR] 2.26 [95% CI 1.42-3.60], p<0.001), clinical progression (HR 2.29 [95% CI 1.32-3.98], p=0.003), and use of hormone therapy (sHR 2.99 [95% CI 1.55-5.76], p=0.001). GC high patients had 5-year freedom from biochemical progression of 45% vs. 71% for GC low-intermediate. Dose escalation did not benefit the overall cohort, nor patients with lower vs. higher GC scores.
CONCLUSIONS
This study represents the first contemporary randomized controlled trial in patients treated with early SRT without concurrent hormone therapy or pelvic nodal RT that has validated the prognostic utility of the GC. Independent of standard clinicopathologic variables and RT dose, high-GC patients were more than twice as likely than lower-GC patients to experience biochemical and clinical progression and receive of salvage hormone therapy. This data confirms the clinical value of Decipher GC to personalize the use of concurrent systemic therapy in the postoperative salvage setting
Recommendations for radiation therapy in oligometastatic prostate cancer:An ESTRO-ACROP Delphi consensus
Background and purpose: Oligometastatic prostate cancer is a new and emerging treatment field with only few prospective randomized studies published so far. Despite the lack of strong level I evidence, metastasis-directed therapies (MDT) are widely used in clinical practice, mainly based on retrospective and small phase 2 studies and with a large difference across centers. Pending results of ongoing prospec-tive randomized trials, there is a clear need for more consistent treatment indications and radiotherapy practices.Material and methods: A European Society for Radiotherapy and Oncology (ESTRO) Guidelines Committee consisting of radiation oncologists' experts in prostate cancer was asked to answer a dedicated question-naire, including 41 questions on the main controversial issues with regard to oligometastatic prostate cancer.Results: The panel achieved consensus on patient selection and routine use of prostate-specific mem-brane antigen positron emission tomography (PSMA PET) imaging as preferred staging and restaging imaging. MDT strategies are recommended in the de novo oligometastatic, oligorecurrent and oligopro-gressive disease setting for nodal, bone and visceral metastases. Radiation therapy doses, volumes and techniques were discussed and commented.Conclusion: These recommendations have the purpose of providing standardization and consensus to optimize the radiotherapy treatment of oligometastatic prostate cancer until mature results of random-ized trials are available.AT would like to acknowledge the support of Cancer Research UK (C33589/A28284 and C7224/A28724) . This project represents independent research supported by the National Institute for Health research (NIHR) Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research, London. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care
Detailed Molecular and Immune Marker Profiling of Archival Prostate Cancer Samples Reveals an Inverse Association between TMPRSS2:ERG Fusion Status and Immune Cell Infiltration
Prostate cancer is a significant global health issue and limitations to current patient management pathways often result in over- or under-treatment. New ways to stratify patients are urgently needed. We conducted a feasibility study of such novel assessments looking for associations between genomic changes and lymphocyte infiltration. An innovative workflow utilizing an in-house targeted sequencing panel, immune cell profiling using an image analysis pipeline, RNA-Seq, and exome sequencing in select cases was tested. Gene fusions were profiled by RNA-seq in 27/27 cases and a significantly higher TIL count was noted in tumors without a TMPRSS2:ERG fusion compared to those with the fusion (P = 0.01). Although this finding was not replicated in a larger validation set (n=436) of The Cancer Genome Atlas images, there was a trend in the same direction. Differential expression analysis of TIL-High and TIL-Low tumors revealed the enrichment of both innate and adaptive immune response pathways. Mutations in mismatch repair genes (MLH1 and MSH6 mutations in 1/27 cases) were identified. We describe a potential immune escape mechanism in TMPRSS2:ERG fusion positive tumors. Detailed profiling, as shown here, can provide novel insights into tumor biology. Likely differences with findings with other cohorts are related to methods used to define region of interest, but this warrants further study in a larger cohort
Fstl1 Antagonizes BMP Signaling and Regulates Ureter Development
Bone morphogenetic protein (BMP) signaling pathway plays important roles in urinary tract development although the detailed regulation of its activity in this process remains unclear. Here we report that follistatin-like 1 (Fstl1), encoding a secreted extracellular glycoprotein, is expressed in developing ureter and antagonizes BMP signaling activity. Mouse embryos carrying disrupted Fstl1 gene displayed prominent hydroureter arising from proximal segment and ureterovesical junction defects. These defects were associated with significant reduction in ureteric epithelial cell proliferation at E15.5 and E16.5 as well as absence of subepithelial ureteral mesenchymal cells in the urinary tract at E16.5 and E18.5. At the molecular level, increased BMP signaling was found in Fstl1 deficient ureters, indicated by elevated pSmad1/5/8 activity. In vitro study also indicated that Fstl1 can directly bind to ALK6 which is specifically expressed in ureteric epithelial cells in developing ureter. Furthermore, Sonic hedgehog (SHH) signaling, which is crucial for differentiation of ureteral subepithelial cell proliferation, was also impaired in Fstl1-/- ureter. Altogether, our data suggest that Fstl1 is essential in maintaining normal ureter development by antagonizing BMP signaling
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