13 research outputs found

    Scaling limits and influence of the seed graph in preferential attachment trees

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    We are interested in the asymptotics of random trees built by linear preferential attachment, also known in the literature as Barab\'asi-Albert trees or plane-oriented recursive trees. We first prove a conjecture of Bubeck, Mossel \& R\'acz concerning the influence of the seed graph on the asymptotic behavior of such trees. Separately we study the geometric structure of nodes of large degrees in a plane version of Barab\'asi-Albert trees via their associated looptrees. As the number of nodes grows, we show that these looptrees, appropriately rescaled, converge in the Gromov-Hausdorff sense towards a random compact metric space which we call the Brownian looptree. The latter is constructed as a quotient space of Aldous' Brownian Continuum Random Tree and is shown to have almost sure Hausdorff dimension 22.Comment: 32 pages, 11 figure

    Scaling limits and influence of the seed graph in preferential attachment trees

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    We are interested in the asymptotics of random trees built by linear preferential attachment, also known in the literature as Barab\'asi-Albert trees or plane-oriented recursive trees. We first prove a conjecture of Bubeck, Mossel \& R\'acz concerning the influence of the seed graph on the asymptotic behavior of such trees. Separately we study the geometric structure of nodes of large degrees in a plane version of Barab\'asi-Albert trees via their associated looptrees. As the number of nodes grows, we show that these looptrees, appropriately rescaled, converge in the Gromov-Hausdorff sense towards a random compact metric space which we call the Brownian looptree. The latter is constructed as a quotient space of Aldous' Brownian Continuum Random Tree and is shown to have almost sure Hausdorff dimension 22.Comment: 32 pages, 11 figure

    Lymphadenectomy for Upper Tract Urothelial Carcinoma: A Systematic Review

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    Background: The role of lymphonodal dissection during surgery for a tumor of the urinary tract remains controversial. Objective: To analyze anatomical bases of lymphonodal dissection in tumors of the upper urinary tract and analyze its impact on survival, recurrence, and staging. Acquisition of data: A web-based search for scientific articles using Medline/Pubmed was carried out to identify and analyze articles on the practice and the role of lymphonodal dissection in this indication. Data Synthesis: The lymphatic drainage of the upper urinary tract has rarely been studied and is poorly understood. The lymphonodal metastatic extension is the most common extension in upper urinary tract urothelial carcinoma. Lymphnode invasion is a clear independent poor prognostic factor. Therefore, it seems legitimate to offer an extended lymphonodal dissection to patients undergoing surgery to cure these tumors. When lymphnodes dissection respects clear anatomical principles based on the location of the primary tumor and its extension, it improves both survival and recurrence rates. This result could be secondary to the treatment of subclinical metastatic disease. Conclusion: An extended lymphadenectomy during surgery for upper urinary tract urothelial carcinoma following strict anatomical pattern improves staging with a highly probable therapeutic benefit

    Ejaculations and Benign Prostatic Hyperplasia: An Impossible Compromise? A Comprehensive Review

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    International audienceBackground: Benign prostatic hyperplasia (BPH) is commonly responsible for lower urinary tract symptoms (LUTS) in men aged 50 or over. Sexual dysfunctions, such as ejaculatory disorders (EjD), go along with LUTS but are frequently overlooked in the initial evaluation. This review aimed to detail BPH-related EjD, as well as their modifications by medical, surgical, and interventional treatments. Methods: We conducted a narrative review looking for publications between 1990 and 2020, regarding physiopathology, epidemiology, evaluation, and therapeutic management (medical, surgical, and interventional) of BPH-related EjD. Results: Sixty-five articles were included in our final analysis. Forty-six percent of men presenting with LUTS reported EjD. If the prevalence increases with age and LUTS severity, the functional impairment is not correlated with age. Several self-questionnaires evaluated the sexual function, but only four approaches are specific to EjD. Medical therapies were exposed to anejaculation, rather than retrograde ejaculation (RE) (4–30% (alpha-blockers), 4–18% (5-alpha-reductase inhibitors)). Regarding surgical therapies, trans-urethral resection of the prostate (TURP) and incision of the prostate (TUIP) are associated with 50–70% and 21–35% of RE. The RE rate is important after open simple prostatectomy but can be reduced with robotic approaches and urethral sparing techniques (19%). Anatomic endoscopic enucleation of the prostate (AEEP) with or without a laser source is associated with an 11–36% RE rate, according to supramontanal preservation. Recent surgical techniques (Rezum©, Aquablation©, or Urolift©) were developed to preserve antegrade ejaculation with promising short-term results. Regardless of the surgical approach, anatomic studies suggest that the preservation of peri-montanal tissue (7.5 mm laterally; 10 mm proximally) is primordial to avoid post-operative RE. Finally, prostate artery embolization (PAE) limits the RE rate but exposes it to a 12 months 10% re-intervention rate. Conclusion: EjD concerns almost half of the patients presenting BPH-related LUTS. Initial evaluation of EjD impairment is primordial before medical or surgical therapy. Peri-montanal tissue preservation represents a key point for antegrade ejaculation preservation, regardless of the surgical option

    Combination intravesical chemotherapy for non-muscle invasive bladder cancer (NMIBC) as first-line or rescue therapy: where do we stand now?

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    The combination of intravesical gemcitabine (Gem) with docetaxel (Doce) or with mitomycin C (MMC) has been used in the primary setting as an alternative to Bacillus Calmette-Guerin (BCG) to treat high-risk (HR) and intermediate-risk (IR) non-muscle invasive bladder cancer (NMIBC), as well in the rescue setting for patients in whom BCG has failed. Efficacy and safety of Gem/Doce and Gem/MMC to treat NMIBC in BCG-naive and failure settings. In the BCG-naive setting, Gem/Doce was the primary alternative combination therapy reported, with a weighted mean of 12- and 24-month recurrence-free survival (RFS) of 79% and 77% for HR disease and 84% and 76% for IR disease, respectively. In the HR BCG-failure setting, the weighted mean of 12- and 24-month RFS was 60% and 42% for Gem/Doce and 63% and 40% for Gem/MMC. While patients without BCG exposure and papillary disease only benefit the most from Gem/Doce, there is also reasonable efficacy in BCG refractory disease and CIS. Combination therapy is well tolerated, with grade III toxicity reported in less than 1% of patients. Unlike single-agent chemotherapy, intravesical Gem/Doce is considered effective and safe regardless of risk-stratification.</p

    An HMM approach expands the landscape of sesquiterpene cyclases across the kingdom Fungi

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    International audienceSesquiterpene cyclases (STC) catalyse the cyclization of the C15 molecule farnesyl diphosphate into a vast variety of mono- or polycyclic hydrocarbons and, for a few enzymes, oxygenated structures, with diverse stereogenic centres. The huge diversity in sesquiterpene skeleton structures in nature is primarily the result of the type of cyclization driven by the STC. Despite the phenomenal impact of fungal sesquiterpenes on the ecology of fungi and their potentials for applications, the fungal sesquiterpenome is largely untapped. The identification of fungal STC is generally based on protein sequence similarity with characterized enzymes. This approach has improved our knowledge on STC in a few fungal species, but it has limited success for the discovery of distant sequences. Besides, the tools based on secondary metabolite biosynthesis gene clusters have shown poor performance for terpene cyclases. Here, we used four sets of sequences of fungal STC that catalyse four types of cyclization, and specific amino acid motives to identify phylogenetically related sequences in the genomes of basidiomycetes fungi from the order Polyporales. We validated that four STC genes newly identified from the genome sequence of Leiotrametes menziesii , each classified in a different phylogenetic clade, catalysed a predicted cyclization of farnesyl diphosphate. We built HMM models and searched STC genes in 656 fungal genomes genomes. We identified 5605 STC genes, which were classified in one of the four clades and had a predicted cyclization mechanism. We noticed that the HMM models were more accurate for the prediction of the type of cyclization catalysed by basidiomycete STC than for ascomycete STC

    Oncological Outcomes of Distal Ureterectomy for High-Risk Urothelial Carcinoma: A Multicenter Study by The French Bladder Cancer Committee

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    International audienceUpper urinary tract urothelial carcinoma (UTUC) is an uncommon disease and its gold-standard treatment is radical nephroureterectomy (RNU). Distal ureterectomy (DU) might be an alternative for tumors of the distal ureter but its indications remain unclear. Here, we aimed to evaluate the oncological outcomes of DU for UTUC of the pelvic ureter. We performed a multicenter retrospective analysis of patients with UTUC who underwent DU. The primary endpoint was 5-year cancer-specific survival (CSS), followed by overall survival (OS), intravesical recurrence-free (IVR) and homolateral urinary tract recurrence-free (HUR) survivals as secondary endpoints. Univariate and multivariate Cox regressions were performed to assess factors associated with outcomes. 155 patients were included, 91% of which were high-risk. 5-year CSS was 84.4%, OS was 71.9%, IVR-free survival was 43.6% and HUR-free survival was 74.4%. Multifocality, high grade and tumor size were the most significant predictors of survival endpoints. Of note, neither hydronephrosis nor pre-operative diagnostic ureteroscopy/JJ stent were associated with any of the endpoints. Perioperative morbidity was minimal. In conclusion, DU stands as a possible alternative to RNU for UTUC of the pelvic ureter. Close monitoring is mandatory due to the high risk of recurrence in the remaining urinary tract
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