100 research outputs found
Quantitative estimates for the long time behavior of an ergodic variant of the telegraph process
Motivated by stability questions on piecewise deterministic Markov models of
bacterial chemotaxis, we study the long time behavior of a variant of the
classic telegraph process having a non-constant jump rate that induces a drift
towards the origin. We compute its invariant law and show exponential
ergodicity, obtaining a quantitative control of the total variation distance to
equilibrium at each instant of time. These results rely on an exact description
of the excursions of the process away from the origin and on the explicit
construction of an original coalescent coupling for both velocity and position.
Sharpness of the obtained convergence rate is discussed.Comment: Definitive version of former paper "Quantitative estimates for the
long time behavior of a PDMP describing the movement of bacteria", now
accepted in Advances in Applied Probability. Presentation changed. A
diffusive scaling limit result is added. Sharpness of the long-time
convergence rate is discussed. 20 pages, 3 figure
Long time behavior of telegraph processes under convex potentials
We study the long-time behavior of variants of the telegraph process with
position-dependent jump-rates, which result in a monotone gradient-like drift
toward the origin. We compute their invariant laws and obtain, via
probabilistic couplings arguments, some quantitative estimates of the total
variation distance to equilibrium. Our techniques extend ideas previously
developed for a simplified piecewise deterministic Markov model of bacterial
chemotaxis.Comment: 26 pages, 3 figure
Developments in the Surgical Approach to Staging and Resection of Rhabdomyosarcoma
Local treatment; Rhabdomyosarcoma; SurgeryTratamiento local; Rabdomiosarcoma; CirugĂaTractament local; Rabdomiosarcoma; CirurgiaAlthough survival after rhabdosarcoma treatment has improved over the years, one third of patients still develop locoregional relapse. This review aims to highlight developments pertaining to staging and local treatment of specific RMS tumor sites, including head and neck, chest/trunk, bladder-prostate, female genito-urinary, perianal, and extremity sites
Outcome of patients with undifferentiated embryonal sarcoma of the liver treated according to European soft tissue sarcoma protocols
Liver; Pediatrics; SarcomaFetge; Pediatria; SarcomaHĂgado; PediatrĂa; SarcomaBackground
To assess the outcomes of pediatric patients with undifferentiated embryonal sarcoma of the liver (UESL) and treatment including at least surgery and systemic chemotherapy.
Methods
This study included patients aged up to 21 years with a pathological diagnosis of UESL prospectively enrolled from 1995 to 2016 in three European trials focusing on the effects of surgical margins, preoperative chemotherapy, use of radiotherapy (RT), and chemotherapy.
Results
Out of 65 patients with a median age at diagnosis of 8.7 years (0.6â20.8), 15 had T2 tumors, and one had lymph node spread, 14 were Intergroup Rhabdomyosarcoma Study (IRS) I, nine IRS II, 38 IRS III, and four IRS IV. Twenty-eight upfront surgeries resulted in five operative spillages and 11 infiltrated surgical margins, whereas 37 delayed surgeries resulted in no spillages (p = .0119) and three infiltrated margins (p = .0238). All patients received chemotherapy, including anthracyclines in 47. RT was administered in 15 patients. With a median follow-up of 78.6 months, 5-year overall and event-free survivals (EFS) were 90.1% (95% confidence interval [CI]: 79.2â95.5) and 89.1% (95% CI: 78.4â94.6), respectively. Two out four local relapses had previous infiltrated margins and two out of three patients with metastatic relapses received reduced doses of alkylating agents. Infiltrated margins (p = .1607), T2 stage (p = .3870), use of RT (p = .8731), and anthracycline-based chemotherapy (p = .1181) were not correlated with EFS.
Conclusions
Multimodal therapy improved the outcome of UESL. Neoadjuvant chemotherapy for pediatric patients increases the probability of complete surgical resection. The role of anthracyclines and RT for localized disease remains unclear
Interleukin-18 produced by bone marrow- derived stromal cells supports T-cell acute leukaemia progression
International audienceDevelopment of novel therapies is critical for T-cell acute leukae-mia (T-ALL). Here, we investigated the effect of inhibiting the MAPK/MEK/ERK pathway on T-ALL cell growth. Unexpectedly, MEK inhibitors (MEKi) enhanced growth of 70% of human T-ALL cell samples cultured on stromal cells independently of NOTCH activa-tion and maintained their ability to propagate in vivo. Similar results were obtained when T-ALL cells were cultured with ERK1/ 2-knockdown stromal cells or with conditioned medium from MEKi-treated stromal cells. Microarray analysis identified interleu-kin 18 (IL-18) as transcriptionally up-regulated in MEKi-treated MS5 cells. Recombinant IL-18 promoted T-ALL growth in vitro, whereas the loss of function of IL-18 receptor in T-ALL blast cells decreased blast proliferation in vitro and in NSG mice. The NFKB pathway that is downstream to IL-18R was activated by IL-18 in blast cells. IL-18 circulating levels were increased in T-ALL-xeno-grafted mice and also in T-ALL patients in comparison with controls. This study uncovers a novel role of the pro-inflammatory cytokine IL-18 and outlines the microenvironment involvement in human T-ALL development
Outcome of patients with undifferentiated embryonal sarcoma of the liver treated according to European soft tissue sarcoma protocols
Background: To assess the outcomes of pediatric patients with undifferentiated embryonal sarcoma of the liver (UESL) and treatment including at least surgery and systemic chemotherapy. Methods: This study included patients aged up to 21 years with a pathological diagnosis of UESL prospectively enrolled from 1995 to 2016 in three European trials focusing on the effects of surgical margins, preoperative chemotherapy, use of radiotherapy (RT), and chemotherapy. Results: Out of 65 patients with a median age at diagnosis of 8.7 years (0.6â20.8), 15 had T2 tumors, and one had lymph node spread, 14 were Intergroup Rhabdomyosarcoma Study (IRS) I, nine IRS II, 38 IRS III, and four IRS IV. Twenty-eight upfront surgeries resulted in five operative spillages and 11 infiltrated surgical margins, whereas 37 delayed surgeries resulted in no spillages (p =.0119) and three infiltrated margins (p =.0238). All patients received chemotherapy, including anthracyclines in 47. RT was administered in 15 patients. With a median follow-up of 78.6 months, 5-year overall and event-free survivals (EFS) were 90.1% (95% confidence interval [CI]: 79.2â95.5) and 89.1% (95% CI: 78.4â94.6), respectively. Two out four local relapses had previous infiltrated margins and two out of three patients with metastatic relapses received reduced doses of alkylating agents. Infiltrated margins (p =.1607), T2 stage (p =.3870), use of RT (p =.8731), and anthracycline-based chemotherapy (p =.1181) were not correlated with EFS. Conclusions: Multimodal therapy improved the outcome of UESL. Neoadjuvant chemotherapy for pediatric patients increases the probability of complete surgical resection. The role of anthracyclines and RT for localized disease remains unclear
Prevalence and risk factors of hypotension associated with preload-dependence during intermittent hemodialysis in critically ill patients
Brachytherapy for rhabdomyosarcoma: Survey of international clinical practice and development of guidelines
BACKGROUND AND PURPOSE: The purpose of this study was to address the lack of published data on the use of brachytherapy in pediatric rhabdomyosarcoma by describing current practice as starting point to develop consensus guidelines. MATERIALS AND METHODS: An international expert panel on the treatment of pediatric rhabdomyosarcoma comprising 24 (pediatric) radiation oncologists, brachytherapists and pediatric surgeons met for a Brachytherapy Workshop hosted by the European paediatric Soft tissue Sarcoma Study Group (EpSSG). The panel's clinical experience, the results of a previously distributed questionnaire, and a review of the literature were presented. RESULTS: The survey indicated the most common use of brachytherapy to be in combination with tumor resection, followed by brachytherapy as sole local therapy modality. HDR was increasingly deployed in pediatric practice, especially for genitourinary sites. Brachytherapy planning was mostly by 3D imaging based on CT. Recommendations for patient selection, treatment requirements, implant technique, delineation, dose prescription, dose reporting and clinical management were defined. CONCLUSIONS: Consensus guidelines for the use of brachytherapy in pediatric rhabdomyosarcoma have been developed through multicenter collaboration establishing the basis for future work. These have been adopted for the open EpSSG overarching study for children and adults with Frontline and Relapsed RhabdoMyoSarcoma (FaR-RMS)
Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower RhĂŽne Valley, France
On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower RhĂŽne Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional CĂ©venne fault system in a context of present-day compressional tectonics
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