The histology of ossification in the caudal fin of Larval Zebrafish, Danio rerio

1 online resource (59 unnumbered pages) : illustrations (some colour), charts (some colour), graphs (some colour)Includes abstract and appendices.Includes bibliographical references (unnumbered pages 45-50).Endochondral ossification is a bone developing process in which a cartilaginous template gets replaced by bone. Zebrafish, Danio rerio, are teleost fish that undergo this process throughout their skeletons. This thesis is focussed on their tail bones, specifically within the hypurals and parhypural of the caudal fin. The morphological changes in the cells of the hypurals and parhypural during ossification have not been recorded so the aim of this study is to investigate these changes taking a histological approach. To determine the morphological cellular changes Hall Brunt’s Quadruple staining was used to stain the bone and cartilage within zebrafish sized 4 to 9 mm standard length. Changes within the chondrocytes were measured and descriptions of the amount of ossification were made. It was found that all five hypurals and the parhypural begin ossifying around 5.0 mm SL, while the chondrocytes underwent hypertrophy by 7.0 mm SL there was a lower percentage of hypertrophied chondrocytes in 8.0 – 9.0 mm SL specimens for hypurals 2 and 3. Hypural 2 and 3 were the elements primarily focused on, that had an increase in total hypural length (µm). These results suggest that the hypurals share features of both endochondral and perichondral ossification. Further studies are needed to further understand ossification within the zebrafish caudal fin

Pharmacogenomic associations of adverse drug reactions in asthma:systematic review and research prioritisation

We would like to thank the NIHR Collaboration for Leadership in Applied Health Research and Care North West Coast (CLAHRC) for funding Amanda McKenna’s internship, and Charlotte Kings MPhil, and the members of the PiCA consortia for their help in completing the survey. U. Potočnik, K. Repnik and V. Berce were supported by SysPharmPedia grant, co-financed by Ministry of Education, Science and Sport of the Republic of Slovenia Author information These authors contributed equally: Charlotte King, Amanda McKenna These authors jointly supervised this work: Ian Sinha, Daniel B. HawcuttPeer reviewedPublisher PD

Alternative-NHEJ Is a Mechanistically Distinct Pathway of Mammalian Chromosome Break Repair

Characterizing the functional overlap and mutagenic potential of different pathways of chromosomal double-strand break (DSB) repair is important to understand how mutations arise during cancer development and treatment. To this end, we have compared the role of individual factors in three different pathways of mammalian DSB repair: alternative-nonhomologous end joining (alt-NHEJ), single-strand annealing (SSA), and homology directed repair (HDR/GC). Considering early steps of repair, we found that the DSB end-processing factors KU and CtIP affect all three pathways similarly, in that repair is suppressed by KU and promoted by CtIP. In contrast, both KU and CtIP appear dispensable for the absolute level of total-NHEJ between two tandem I-SceI–induced DSBs. During later steps of repair, we find that while the annealing and processing factors RAD52 and ERCC1 are important to promote SSA, both HDR/GC and alt-NHEJ are significantly less dependent upon these factors. As well, while disruption of RAD51 causes a decrease in HDR/GC and an increase in SSA, inhibition of this factor did not affect alt-NHEJ. These results suggest that the regulation of DSB end-processing via KU/CtIP is a common step during alt-NHEJ, SSA, and HDR/GC. However, at later steps of repair, alt-NHEJ is a mechanistically distinct pathway of DSB repair, and thus may play a unique role in mutagenesis during cancer development and therapy

Pharmacogenomic associations of adverse drug reactions in asthma: systematic review and research prioritisation

A systematic review of pharmacogenomic studies capturing adverse drug reactions (ADRs) related to asthma medications was undertaken, and a survey of Pharmacogenomics in Childhood Asthma (PiCA) consortia members was conducted. Studies were eligible if genetic polymorphisms were compared with suspected ADR(s) in a patient with asthma, as either a primary or secondary outcome. Five studies met the inclusion criteria. The ADRs and polymorphisms identified were change in lung function tests (rs1042713), adrenal suppression (rs591118), and decreased bone mineral density (rs6461639) and accretion (rs9896933, rs2074439). Two of these polymorphisms were replicated within the paper, but none had external replication. Priorities from PiCA consortia members (representing 15 institution in eight countries) for future studies were tachycardia (SABA/LABA), adrenal suppression/crisis and growth suppression (corticosteroids), sleep/behaviour disturbances (leukotriene receptor antagonists), and nausea and vomiting (theophylline). Future pharmacogenomic studies in asthma should collect relevant ADR data as well as markers of efficacy

Nfkb2 variants reveal a p100-degradation threshold that defines autoimmune susceptibility

NF-κB2/p100 (p100) is an inhibitor of κB (IκB) protein that is partially degraded to produce the NF-κB2/p52 (p52) transcription factor. Heterozygous NFKB2 mutations cause a human syndrome of immunodeficiency and autoimmunity, but whether autoimmunity arises from insufficiency of p52 or IκB function of mutated p100 is unclear. Here, we studied mice bearing mutations in the p100 degron, a domain that harbors most of the clinically recognized mutations and is required for signal-dependent p100 degradation. Distinct mutations caused graded increases in p100-degradation resistance. Severe p100-degradation resistance, due to inheritance of one highly degradation-resistant allele or two subclinical alleles, caused thymic medullary hypoplasia and autoimmune disease, whereas the absence of p100 and p52 did not. We inferred a similar mechanism occurs in humans, as the T cell receptor repertoires of affected humans and mice contained a hydrophobic signature of increased self-reactivity. Autoimmunity in autosomal dominant NFKB2 syndrome arises largely from defects in nonhematopoietic cells caused by the IκB function of degradation-resistant p100

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Effects of a hybrid digital Cognitive Behavioural Therapy for Insomnia and Emotion Regulation in the workplace (SLEEP) : study protocol for a randomised waitlist-control trial

Introduction: This trial tests the efficacy of implementing a hybrid digital cognitive behavioural therapy for insomnia (dCBT-I) and emotion regulation (ER) in the workplace. The study protocol follows on the SPIRIT (Standard Protocol Items for Randomized Trials) 2013 recommendations. Methods and analysis: Mixed methods evaluation with a two-arm randomised waitlist control design of a six weeks dCBT-I+ER intervention through self-guided online platform and four videoconferencing therapy sessions. A process evaluation will examine fidelity of delivery and experiences of the intervention. Primary outcomes are the Insomnia Severity Index (ISI), the Patient Health Questionnaire (PHQ-9) and the Generalised Anxiety Disorder (GAD-7). Secondary outcomes are job productivity, job satisfaction, well-being, quality of life, self-reported (sleep diary data) and objective (actigraphy) sleep parameters, and usage of online intervention platform. Assessments take place at baseline (T0), week-8 post-treatment (T1), and week-12 post-randomisation (T2). We will recruit 156 workers with sleep and emotion regulation problems ranging from subclinical to clinical levels not engaged in treatment at the time of the trial

A Cluster of Pediatric Invasive Group A Streptococcus Disease in Melbourne, Australia, Coinciding with a High-Burden Influenza Season

Background Invasive group A streptococcal disease (IGAS) carries significant morbidity and mortality in children. Fluctuations in disease incidence are well documented. However, the modulating factors that contribute to these changes remain unclear. Prospective monitoring of IGAS cases in Victoria, Australia, showed an increased number of cases in 2017, coinciding with a peak of influenza illness. Methods Children identified to have IGAS are prospectively monitored in Melbourne through a disease surveillance network. Data on their presentation, investigations, and clinical course are collected. An increased number of cases identified between June 1, 2017, and October 31, 2017, have been retrospectively analyzed. Results We identified 22 cases of pediatric IGAS during the study period. Increased case detection occurred during a period of increased influenza disease. Of 11 children in our cohort who underwent respiratory viral testing, 4 were confirmed to have concurrent respiratory tract illnesses, and 2 were confirmed to have influenza.SCOPUS: ar.jDecretOANoAutActifinfo:eu-repo/semantics/publishe

Multimodal ocular imaging of known and novel corneal stromal disorders in dogs.

BackgroundImaging features obtained with Fourier-domain optical coherence tomography (FD-OCT) and in vivo confocal microscopy (IVCM) for corneal stromal disorders have been sparsely reported in dogs. This case report is a compilation of imaging features for three cases of different stromal disorders of the canine cornea which have not yet been reported elsewhere.Case presentationLipid deposition in case 1 appeared as needle-shaped hyperreflective lines along the collagen lamellae, which correlated histologically with lipid clefts. In case 2, glycosaminoglycan accumulation by mucopolysaccharidosis type 1 caused diffuse stromal hyperreflectivity and depletion of keratocytes on IVCM and was associated with secondary corneal degeneration presumed to be calcium deposition. In case 3, posterior corneal stromal opacities in the absence of ocular inflammation were identified. Hyperreflective particles were scattered in the middle and posterior corneal stroma on FD-OCT. With IVCM, hyperreflective deposits were identified within keratocytes and the number of enlarged keratocytes containing hyperreflective deposits increased towards the posterior stroma. The bilateral, non-inflammatory nature and unique appearance with IVCM is most consistent with a posterior stromal dystrophy reminiscent of pre-Descemet corneal dystrophy described in humans.ConclusionsIn vivo multimodal corneal imaging facilitated instantaneous microstructural analysis and may be valuable in the differential diagnosis of corneal stromal disorders in veterinary clinical practice. The non-specific nature of imaging findings occurs in some conditions such as mucopolysaccharidosis, thus in vivo corneal imaging should be complemented with other gold standard methods of definitive diagnosis