Characterization of yeast mutants lacking alkaline ceramidases YPC1 and YDC1

Humans and yeast possess alkaline ceramidases located in the early secretory pathway. Single deletions of the highly homologous yeast alkaline ceramidases YPC1 and YDC1 have very little genetic interactions or phenotypes. Here, we performed chemical-genetic screens to find deletions/conditions that would alter the growth of ypc1∆ydc1∆ double mutants. These screens were essentially negative, demonstrating that ceramidase activity is not required for cell growth even under genetic stresses. A previously reported protein targeting defect of ypc1∆ could not be reproduced and reported abnormalities in sphingolipid biosynthesis detected by metabolic labeling do not alter the mass spectrometric lipid profile of ypc1∆ydc1∆ cells. Ceramides of ypc1∆ydc1∆ remained normal even in presence of aureobasidin A, an inhibitor of inositolphosphorylceramide synthase. Moreover, in caloric restriction conditions Ypc1p reduces chronological life span. A novel finding is that, when working backwards as a ceramide synthase in vivo, Ypc1p prefers C24 and C26 fatty acids as substrates, whereas it prefers C16:0, when solubilized in detergent and working in vitro. Therefore, its physiological activity may not only concern the minor ceramides containing C14 and C16. Intriguingly, so far the sole discernable benefit of conserving YPC1 for yeast resides with its ability to convey relative resistance toward H₂O₂

Antibiotic treatment-induced dysbiosis differently affects BDNF and TrkB expression in the brain and in the gut of juvenile mice

Antibiotic use during adolescence may result in dysbiosis-induced neuronal vulnerability both in the enteric nervous system (ENS) and central nervous system (CNS) contributing to the onset of chronic gastrointestinal disorders, such as irritable bowel syndrome (IBS), showing significant psychiatric comorbidity. Intestinal microbiota alterations during adolescence influence the expression of molecular factors involved in neuronal development in both the ENS and CNS. In this study, we have evaluated the expression of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor tropomyosin-related kinase B (TrkB) in juvenile mice ENS and CNS, after a 2-week antibiotic (ABX) treatment. In both mucosa and mucosa-deprived whole-wall small intestine segments of ABX-treated animals, BDNF and TrKB mRNA and protein levels significantly increased. In longitudinal muscle-myenteric plexus preparations of ABX-treated mice the percentage of myenteric neurons staining for BDNF and TrkB was significantly higher than in controls. After ABX treatment, a consistent population of BDNF-and TrkB-immunoreactive neurons costained with SP and CGRP, suggesting up-regulation of BDNF signaling in both motor and sensory myenteric neurons. BDNF and TrkB protein levels were downregulated in the hippocampus and remained unchanged in the prefrontal cortex of ABX-treated animals. Immunostaining for BDNF and TrkB decreased in the hippocampus CA3 and dentate gyrus subregions, respectively, and remained unchanged in the prefrontal cortex. These data suggest that dysbiosis differentially influences the expression of BDNF-TrkB in the juvenile mice ENS and CNS. Such changes may potentially contribute later to the development of functional gut disorders, such as IBS, showing psychiatric comorbidity

Enhanced recovery after surgery: are we ready, and can we afford not to implement these pathways for patients undergoing radical cystectomy?

Enhanced recovery after surgery (ERAS) for radical cystectomy seems logical, but our study has shown a paucity in the level of clinical evidence. As part of the ERAS Society, we welcome global collaboration to collect evidence that will improve patient outcomes

The yeast P5 type ATPase, Spf1, regulates manganese transport into the endoplasmic reticulum

The endoplasmic reticulum (ER) is a large, multifunctional and essential organelle. Despite intense research, the function of more than a third of ER proteins remains unknown even in the well-studied model organism Saccharomyces cerevisiae. One such protein is Spf1, which is a highly conserved, ER localized, putative P-type ATPase. Deletion of SPF1 causes a wide variety of phenotypes including severe ER stress suggesting that this protein is essential for the normal function of the ER. The closest homologue of Spf1 is the vacuolar P-type ATPase Ypk9 that influences Mn2+ homeostasis. However in vitro reconstitution assays with Spf1 have not yielded insight into its transport specificity. Here we took an in vivo approach to detect the direct and indirect effects of deleting SPF1. We found a specific reduction in the luminal concentration of Mn2+ in ∆spf1 cells and an increase following it’s overexpression. In agreement with the observed loss of luminal Mn2+ we could observe concurrent reduction in many Mn2+-related process in the ER lumen. Conversely, cytosolic Mn2+-dependent processes were increased. Together, these data support a role for Spf1p in Mn2+ transport in the cell. We also demonstrate that the human sequence homologue, ATP13A1, is a functionally conserved orthologue. Since ATP13A1 is highly expressed in developing neuronal tissues and in the brain, this should help in the study of Mn2+-dependent neurological disorders

Supportive interventions to improve physiological and psychological health outcomes among patients undergoing cystectomy: A systematic review

Background Our understanding of effective perioperative supportive interventions for patients undergoing cystectomy procedures and how these may affect short and long-term health outcomes is limited. Methods Randomised controlled trials involving any non-surgical, perioperative interventions designed to support or improve the patient experience for patients undergoing cystectomy procedures were reviewed. Comparison groups included those exposed to usual clinical care or standard procedure. Studies were excluded if they involved surgical procedure only, involved bowel preparation only or involved an alternative therapy such as aromatherapy. Any short and long-term outcomes reflecting the patient experience or related urological health outcomes were considered. Results 19 articles (representing 15 individual studies) were included for review. Heterogeneity in interventions and outcomes across studies meant meta-analyses were not possible. Participants were all patients with bladder cancer and interventions were delivered over different stages of the perioperative period. The overall quality of evidence and reporting was low and outcomes were predominantly measured in the short-term. However, the findings show potential for exercise therapy, pharmaceuticals, ERAS protocols, psychological/educational programmes, chewing gum and nutrition to benefit a broad range of physiological and psychological health outcomes. Conclusions Supportive interventions to date have taken many different forms with a range of potentially meaningful physiological and psychological health outcomes for cystectomy patients. Questions remain as to what magnitude of short-term health improvements would lead to clinically relevant changes in the overall patient experience of surgery and long-term recovery

Pressure tuning of charge ordering in iron oxide

A Verwey-type charge-ordering transition in magnetite at 120 K leads to the formation of linear units of three iron ions with one shared electron, called trimerons. The recently-discovered iron pentoxide (Fe$_4$O$_5$) comprising mixed-valent iron cations at octahedral chains, demonstrates another unusual charge-ordering transition at 150 K involving competing formation of iron trimerons and dimerons. Here, we experimentally show that applied pressure can tune the charge-ordering pattern in Fe$_4$O$_5$ and strongly affect the ordering temperature. We report two charge-ordered phases, the first of which may comprise both dimeron and trimeron units, whereas, the second exhibits an overall dimerization involving both the octahedral and trigonal-prismatic chains of iron in the crystal structure. We link the dramatic change in the charge-ordering pattern in the second phase to redistribution of electrons between the octahedral and prismatic iron chains, and propose that the average oxidation state of the iron cations can pre-determine a charge-ordering pattern

Novel experimental setup for megahertz X-ray diffraction in a diamond anvil cell at the High Energy Density (HED) instrument of the European X-ray Free-Electron Laser (EuXFEL)

The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump-probe X-ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X-ray heating and diffraction of Bi under pressure, obtained using 20 fs X-ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): study protocol for a randomized controlled trial

BACKGROUND: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). METHODS/DESIGN: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH2O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure 6430 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. DISCUSSION: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration metho