33 research outputs found

    A dominant negative mutation uncovers cooperative control of caudal Wolffian duct development by Sprouty genes

    Get PDF
    The Wolffian ducts (WD) are paired epithelial tubules central to the development of the mammalian genitourinary tract. Outgrowths from the WD known as the ureteric buds (UB) generate the collecting ducts of the kidney. Later during development, the caudal portion of the WD will form the vas deferens, epididymis and seminal vesicle in males, and will degenerate in females. While the genetic pathways controlling the development of the UB are firmly established, less is known about those governing development of WD portions caudal to the UB. Sprouty proteins are inhibitors of receptor tyrosine kinase (RTK) signaling in vivo. We have recently shown that homozygous mutation of a conserved tyrosine (Tyr53) of Spry1 results in UB defects indistinguishable from that of Spry1 null mice. Here, we show that heterozygosity for the Spry1 Y53A allele causes caudal WD developmental defects consisting of ectopically branched seminal vesicles in males and persistent WD in females, without affecting kidney development. Detailed analysis reveals that this phenotype also occurs in Spry1+/- mice but with a much lower penetrance, indicating that removal of tyrosine 53 generates a dominant negative mutation in vivo. Supporting this notion, concomitant deletion of one allele of Spry1 and Spry2 also recapitulates the genital phenotype of Spry1Y53A/+ mice with high penetrance. Mechanistically, we show that unlike the effects of Spry1 in kidney development, these caudal WD defects are independent of Ret signaling, but can be completely rescued by lowering the genetic dosage of Fgf10. In conclusion, mutation of tyrosine 53 of Spry1 generates a dominant negative allele that uncovers fine-tuning of caudal WD development by Sprouty genes.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by grants BFU2017-83646-P (MINECO) and PID2020-114947 GB-I00 (MCIU) (both supported by funds from AEI/FEDER, UE) to ME. MV was supported by a predoctoral fellowship from AGAUR. GA and CA and GA are supported by a fellowship from Universitat de Lleida. SC was supported by a Cofund action from the Marie Curie program of the E

    Modulation of Mrp1 (ABCc1) and Pgp (ABCb1) by Bilirubin at the Blood-CSF and Blood-Brain Barriers in the Gunn Rat

    Get PDF
    Accumulation of unconjugated bilirubin (UCB) in the brain causes bilirubin encephalopathy. Pgp (ABCb1) and Mrp1 (ABCc1), highly expressed in the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) respectively, may modulate the accumulation of UCB in brain. We examined the effect of prolonged exposure to elevated concentrations of UCB on expression of the two transporters in homozygous, jaundiced (jj) Gunn rats compared to heterozygous, not jaundiced (Jj) littermates at different developmental stages (2, 9, 17 and 60 days after birth). BBB Pgp protein expression was low in both jj and Jj pups at 9 days (about 16–27% of adult values), despite the up-regulation in jj animals (2 and 1.3 fold higher than age matched Jj animals at P9 and P17–P60, respectively); Mrp1 protein expression was barely detectable. Conversely, at the BCSFB Mrp1 protein expression was rather high (60–70% of the adult values) in both jj and Jj at P2, but was markedly (50%) down-regulated in jj pups starting at P9, particularly in the 4th ventricle choroid plexuses: Pgp was almost undetectable. The Mrp1 protein down regulation was accompanied by a modest up-regulation of mRNA, suggesting a translational rather than a transcriptional inhibition. In vitro exposure of choroid plexus epithelial cells obtained from normal rats to UCB, also resulted in a down-regulation of Mrp1 protein. These data suggest that down-regulation of Mrp1 protein at the BSCFB, resulting from a direct effect of UCB on epithelial cells, may impact the Mrp1-mediated neuroprotective functions of the blood-cerebrospinal fluid barrier and actually potentiate UCB neurotoxicity

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

    Get PDF
    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

    Get PDF
    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

    Get PDF
    Meeting abstrac

    Signal-level integrity and metrics based on the application of quickest detection theory to interference detection

    No full text
    In this paper, we will concentrate on interferences as one of the major impairments that can threat the integrity of mass-market GNSS receivers. While the topic of interference detection has already been covered in the existing GNSS literature, the purpose of this work is to focus on the fast and reliable detection of interferences, using the tools of the so-called “quickest detection” theory. To do so, time plays a relevant role, since we are often interested in minimizing the time for detecting a given threat. This is in contrast to classical detection techniques, where the goal is to maximize the detection probability subject to some probability of false alarm, but where “time” is not explicitly considered. Theoretical results on quickest detectors are complemented in this work with experimental tests using real signals, obtained in the framework of the EC funded iGNSSrx project. The effects of different types of interferences onto the proposed quickest detection techniques are shown and the performance of the designed detection algorithms working in real conditions is presented. The results show how the behavior of the proposed algorithms is satisfactory for being used in integrity monitoring applications

    Authentication by polarization: A powerful anti-spoofing method

    No full text
    This paper presents a method to detect and mitigate a spoofing attack by means of a dual polarized antenna. It exploits the similarity in polarization of spoofed satellites to identify spoofed satellites and copes with three major challenges. A first challenge is to avoid false alarms, which could be triggered by occasional polarization alignment of authentic satellites. The second challenge is the detection of spoofed signals out of a mix of spoofed and non-spoofed signals, as is the case in most practical spoofing attacks. The final challenge is to be able to work with spoofed signals from RHCP spoofing antennas operating from a higher elevation. The technique was developed based on analysis of a large amount of experimental signal data recorded in spoofed and non-spoofed environments. The paper first describes the recording system, which uses a high-performance dual polarized antenna, optimized for low axial ratio. This connects to a multi-frequency multi-constellation receiver, supporting concurrent coherent tracking of the RHCP and LHCP signal components provided by the antenna. We subsequently discuss the measurement campaign. It is rather straightforward to collect data in a variety of non-spoofed environments to build a database of scenarios which are supposed to yield a negative spoofing indication. This doesn’t hold for spoofing scenarios, because of regulatory constraints. Therefore, the spoofing tests were done in a special anechoic chamber which can simulate both polarization and angle of arrival of satellite signals. This wave field synthesis (WFS) testbed was configured to create a mix of satellite signals, some of them emulating authentic signals and the other ones representing the spoofer. The WFS testbed was used to simulate an advanced matched power timing attack. Finally, the paper discusses a new spoofing detection algorithm, based on the experimental data. We present an analysis of the spoofing classification performance, analyzing metrics for probability of false alarm and probability of detection

    Signal-level Integrity and Metrics Based on the Application of Quickest Detection Theory to Multipath Detection

    No full text
    Multipath is one of the major impairments that can threat the integrity of mass-market GNSS receivers (i.e. those mainly used in terrestrial environments). In this context, the purpose of this work is to adopt a quickest detection framework for multipath detection in single-antenna GNSS receivers. This is done with the aim of providing signal-level integrity in GNSS applications. Three different approaches, all of them using the correlator output samples, are proposed in order to cope with a wide range of multipath and NLOS conditions. The results obtained in real field tests confirm the suitability of the proposed post-correlation metrics and the quickest detection framework to improve the navigation performance and to perform real-time quality monitoring. The novelty of this work is the proposal of sequential tests for multipath detection based on quickest detection theory, which provides an optimum level of signal integrity in terms of the trade-off between delay in detecting integrity threats and time between false alarms. This is in contrast to classical detection techniques, where the goal is to maximize the detection probability subject to some probability of false alarm, but where “time” is not explicitly considered
    corecore