Aneuploid proliferation defects in yeast are not driven by copy number changes of a few dosage-sensitive genes

Aneuploidy—the gain or loss of one or more whole chromosome—typically has an adverse impact on organismal fitness, manifest in conditions such as Down syndrome. A central question is whether aneuploid phenotypes are the consequence of copy number changes of a few especially harmful genes that may be present on the extra chromosome or are caused by copy number alterations of many genes that confer no observable phenotype when varied individually. We used the proliferation defect exhibited by budding yeast strains carrying single additional chromosomes (disomes) to distinguish between the “few critical genes” hypothesis and the “mass action of genes” hypothesis. Our results indicate that subtle changes in gene dosage across a chromosome can have significant phenotypic consequences. We conclude that phenotypic thresholds can be crossed by mass action of copy number changes that, on their own, are benign.National Institutes of Health (U.S.) (GM056800

HIF1A reduces acute lung injury by optimizing carbohydrate metabolism in the alveolar epithelium

Background: While acute lung injury (ALI) contributes significantly to critical illness, it resolves spontaneously in many instances. The majority of patients experiencing ALI require mechanical ventilation. Therefore, we hypothesized that mechanical ventilation and concomitant stretch-exposure of pulmonary epithelia could activate endogenous pathways important in lung protection. Methods and Findings: To examine transcriptional responses during ALI, we exposed pulmonary epithelia to cyclic mechanical stretch conditions—an in vitro model resembling mechanical ventilation. A genome-wide screen revealed a transcriptional response similar to hypoxia signaling. Surprisingly, we found that stabilization of hypoxia-inducible factor 1A (HIF1A) during stretch conditions in vitro or during ventilator-induced ALI in vivo occurs under normoxic conditions. Extension of these findings identified a functional role for stretch-induced inhibition of succinate dehydrogenase (SDH) in mediating normoxic HIF1A stabilization, concomitant increases in glycolytic capacity, and improved tricarboxylic acid (TCA) cycle function. Pharmacologic studies with HIF activator or inhibitor treatment implicated HIF1A-stabilization in attenuating pulmonary edema and lung inflammation during ALI in vivo. Systematic deletion of HIF1A in the lungs, endothelia, myeloid cells, or pulmonary epithelia linked these findings to alveolar-epithelial HIF1A. In vivo analysis of 13C-glucose metabolites utilizing liquid-chromatography tandem mass-spectrometry demonstrated that increases in glycolytic capacity, improvement of mitochondrial respiration, and concomitant attenuation of lung inflammation during ALI were specific for alveolar-epithelial expressed HIF1A. Conclusions: These studies reveal a surprising role for HIF1A in lung protection during ALI, where normoxic HIF1A stabilization and HIF-dependent control of alveolar-epithelial glucose metabolism function as an endogenous feedback loop to dampen lung inflammation

Retinoic Acid Regulates Endothelial β-catenin Expression and Pericyte Numbers in the Developing Brain Vasculature

The acquisition of brain vascular properties, like tight junctions and pericytes, to form the blood-brain barrier (BBB) is crucial for a properly functioning central nervous system (CNS). Endothelial WNT signaling is a known driver of brain vascular development and BBB properties, however, it is unclear how endothelial WNT signaling is regulated. We recently showed that mouse embryos with disruptions in endothelial retinoic acid (RA) signaling have ectopic WNT signaling in the brain vasculature. Using immunohistochemistical analysis, we show that increased vascular WNT signaling in RA mutants (Pdgfbicre; dnRAR403-flox and Rdh10 mutants) is associated with elevated expression of the WNT transcriptional effector, β-catenin, in the brain endothelium. In vitro immunocytochemistry and proximity ligation studies in brain endothelial cells reveal that RA, through its receptor RARα, regulates β-catenin expression in brain endothelial cells via transcriptional suppression and phosphorylation events that targets β-catenin for proteasomal degradation, the latter dependent on PKCα. We find that one function of RA in regulating vascular WNT signaling is to modulate the pericyte numbers in the developing brain vasculature. RA-mediated regulation of vascular WNT signaling could be needed to prevent over-recruitment of pericytes that might impair endothelial-pericyte interactions crucial for vascular stability

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

The role of dosage sensitive genes in aneuploid phenotypes

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, 2016.Cataloged from PDF version of thesis.Includes bibliographical references.Aneuploidy-the gain or loss of one or more whole chromosomes-typically has an adverse impact on organismal fitness, manifest in conditions such as Down syndrome. A central question is whether aneuploid phenotypes are the consequence of copy number changes of a few especially harmful genes that may be present on the extra chromosome, or are caused by copy number alterations of many genes that confer no observable phenotype when varied individually. We used the proliferation defect exhibited by budding yeast strains carrying single additional chromosomes (disomes) to distinguish between the "few critical genes hypothesis" and the "mass action of genes hypothesis". Our results indicate that subtle changes in gene dosage across a chromosome can have significant phenotypic consequences. We conclude that phenotypic thresholds can be crossed by mass action of copy number changes that on their own are benign.by Megan Ellis Bonney.Ph. D

Increasing Parent-Pediatrician Communication about Children's Psychosocial Problems

Objective To examine the differential effects of two scoring procedures for a parent-completed measure, the Pediatric Symptom Checklist (PSC), designed to assess children's behavioral and emotional functioning, on parent-pediatrician communication concerning psychosocial issues. Methods Prior to their medical appointment, 174 parents of children aged 4-16 were assigned to one of three experimental conditions: (1) typical medical care control, (2) Staff-Scored PSC administration, or (3) Parent-Scored PSC administration. Following the appointment, parent perception of parent-pediatrician communication was assessed. Results For children with more emotional and behavioral problems, participants in the Parent-Scored group and the Staff-Scored group had better parent-pediatrician communication scores than those in the control group. Conclusions Both the Staff-Scored and Parent-Scored administrations of the PSC improved parentpediatrician communication on psychosocial issues. The Parent-Scored PSC removed the scoring burden on the medical personnel. Key words emotional and behavioral functioning; parent-physician communication; pediatric psychosocial screening; psychosocial problem detection. Pediatricians are a near-ideal group for detecting psychosocial problems in children and adolescents and for discussing these issues with families. Pediatricians follow children over time, developing rapport with the family as they make developmental and health recommendations. Despite guidelines developed by the American Academy of Pediatrics (AAP) for increasing pediatricians' attention to psychosocial problems (American Academy of Pediatrics, Committee on Psychosocial Aspects of Child and Family Health, 2001), there continues to be a deficit in pediatricians' communication with parents about children's behavioral and emotional problems. Past studies have reported pediatrician detection rates of psychosocial problems (e.g., behavioral, developmental, and social problems) in children visiting pediatricians ranging from as low as 17-50% Multiple barriers exist that limit pediatricians' communication about children's psychosocial issues. For example, there is a perception that discussing their patients' psychosocial functioning will significantly prolong the length of the visit, despite mixed findings on how the discussion of the issues may impact appointment length In addition to pediatrician barriers, parents may be reluctant to disclose their concerns to pediatricians (Briggs-Gowan, Horwitz, Schwab-Stone, To address these barriers, pediatricians and/or parents have participated in training programs designed to improve communication. However, these interventions tend to be time intensive and costly with benefits often failing to maintain Despite their usefulness and feasibility, standardized screening tools such as the PSC are not being adopted by practitioners in medical settings The purpose of the current study was to extend the evaluation of the PSC to examine its effectiveness for increasing parent-pediatrician communication about children's psychosocial issues in pediatric healthcare settings, as compared to a typical medical care condition. Given the reticence of pediatricians to adopt use of the PSC because of perceived administrative burden, an alternate scoring procedure was introduced in addition to the standard approach. In previous studies, standard administration of the PSC consisted of medical personnel distributing the inventory, collecting it from the parent, and placing it in the child's medical record to be scored, reviewed, and interpreted by the pediatrician. Collection and scoring of the PSC are time-consuming activities that do not require training or special qualifications. The Parent-Scored PSC developed for this study was designed to decrease the administrative burden on the medical facility and increase parent involvement in care. The Parent-Scored PSC involved the following changes: (1) parents were provided with clear, simple scoring instructions and scored their own PSC questionnaire; (2) parents were instructed to maintain possession of the questionnaire and to hand the scored questionnaire directly to the pediatrician during their meeting; and (3) following completion and scoring of the PSC, parents were given interpretation information indicating the range of scores considered to be clinically significant. Providing the interpretation information following completion and scoring of the PSC was intended to insure that parents did not over-or underpathologize their children's behavior based on their knowledge of how to interpret the measure. Parents were also told they could initiate discussion about behaviors on the PSC regardless of the total score, thus taking a dimensional as opposed to a categorical approach to assessment of their children's psychosocial issues. In this investigation, children were divided into those whose PSC scores were high, indicating more emotional and behavioral problems, and those whose scores reflected lower levels of child behavioral difficulties. For children who received high scores on the PSC, it was expected that parents in the two PSC intervention groups would engage in significantly more communication with the pediatricians about their children's psychosocial functioning when compared with those in the typical medical care control group. Similarly, for items endorsed as occurring ''often'' on the PSC, it was hypothesized that parents in the two PSC intervention groups would engage in more communication with their pediatrician about those items than the parents in the control group. No differences in parent-pediatrician communication were expected for parents of children with lower PSC scores since those children with few or minor psychosocial problems would require little if any parent-pediatrician communication about the topic. Pediatricians in the Staff-Scored PSC group and parents in the Parent-Scored PSC group were expected to be the ones who initiated more communication about psychosocial issues. Finally, it was expected 1156 Hayutin, Reed-Knight, Blount, Lewis, and McCormick that parents of children who received high scores, indicating that more issues were in need of discussion, would feel that psychosocial issues were discussed ''enough'' in both PSC groups relative to parents in the standard medical care group. Methods Participants Two hundred and eighty-nine parents of children aged 4-16 attending a medical appointment with a pediatrician in one of two medical clinics in the southeastern United States were approached for participation. Of those, 35 (12%) refused participation because they lacked the time and 25 (8.65%) were not interested. Data were collected in physicians' waiting rooms before and after the child's appointment. Fifty-seven enrollees (19.7%) completed the PSC prior to their appointment but left the office prior to completing the Communication Questionnaire following their appointment. These participants were excluded from the analyses due to incomplete data. The final sample included 172 parents of children attending medical appointments, of which 89 attended a primary care group practice and 83 attended a pediatric gastroenterological practice. Patients seen at the primary care group practice were seen for the following reasons: 56% follow-up/check-up, 12% ear, nose, and throat problems, 6% gastrointestinal problems, 4% dermatological problems, 2% injury, and 19% other/unknown. Patients seen at the pediatric gastrointestinal practice were seen for the following reasons: 27% stomach pain, 20% follow-up/check-up, 13% reflux, 12% constipation, 5% vomiting, and 23% other/unknown. These two settings were selected to increase external validity and speak to the generalizability of the findings. Furthermore, pediatric gastroenterology in particular was chosen due to its being one of the more highly utilized subspecialty services Measures Background information. Parents provided information about the child's age and race, their gender, income, and marital status and reasons for the visit and length of time the child had been the treating physician's patient. Child psychosocial adjustment. Two scoring methods for the 35-item PSC were used