38 research outputs found
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Retrospective evaluation of hyperproteinorrachia without pleocytosis (albuminocytologic dissociation) and survival in dogs
Abstract: Background: Hyperproteinorrachia (raised cerebrospinal fluid total protein [CSFâTP]) without pleocytosis (HP) (also known as albuminocytologic dissociation) is identified in dogs with different neurologic diseases. However, the association between survival and increased CSFâTP is unknown. Objectives: (a) Identify conditions commonly associated with HP in dogs and (b) investigate whether higher CSFâTP concentrations or other relevant factors are associated with 1âyear survival. Methods: This is a retrospective study that identified dogs with HP (Cisternal CSFâTP >0.30 g/L, Lumbar CSFâTP >0.45 g/L with total nucleated cell concentrations [TNCCs] and RBC counts within RIs) from 2008 to 2019: recording signalment, weight, vital parameters, inflammation, neuroanatomic localization, CSFâTP, sampling site, final diagnosis, etiologic classification, and 1âyear survival. Corrected CSFâTP was calculated as CSFâTP minus 0.3 (cisternal) or 0.45 (lumbar or unknown). Descriptive statistics were produced, CSFâTP differences between groups (eg, neuroanatomic localizations) were evaluated using the MannâWhitney U test or KruskalâWallis test (postâhoc testing). The Cox proportional hazards model was used for survival data. Statistical significance was set at a P 0.05). Neoplasia, after adjustment for age, was the only variable associated with a worse survival (P = 0.01 HR: 2.08 (95% CI: 1.65â39.2). CSFâTP was not associated with age (P > 0.05). Conclusions: HP in dogs is associated with a wide range of conditions; the most common conditions are neoplasia, MUO, and IVDD. Higher CSFâTP levels do not correlate with a worse 1âyear survival; however, they do correlate with neoplastic lesions
Species-specific consequences of an E40K missense mutation in superoxide dismutase 1 (SOD1)
A glutamic acid to lysine (E40K) residue substitution in superoxide dismutase 1 (SOD1) is associated with canine degenerative myelopathy: the only naturally occurring large animal model of amyotrophic lateral sclerosis (ALS). The E40 residue is highly conserved across mammals, except the horse, which naturally carries the (dog mutant) K40 residue. Here we hypothesized that in vitro expression of mutant dog SOD1 would recapitulate features of human ALS (ie, SOD1 protein aggregation, reduced cell viability, perturbations in mitochondrial morphology and membrane potential, reduced ATP production, and increased superoxide ion levels); further, we hypothesized that an equivalent equine SOD1 variant would share similar perturbations in vitro, thereby explain horsesâ susceptibility to certain neurodegenerative diseases. As in human ALS, expression of mutant dog SOD1 was associated with statistically significant increased aggregate formation, raised superoxide levels (ROS), and altered mitochondrial morphology (increased branching (form factor)), when compared to wildâtype dog SOD1âexpressing cells. Similar deficits were not detected in cells expressing the equivalent horse SOD1 variant. Our data helps explain the ALSâassociated cellular phenotype of dogs expressing the mutant SOD1 protein and reveals that speciesâspecific sequence conservation does not necessarily predict pathogenicity. The work improves understanding of the etiopathogenesis of canine degenerative myelopathy
Phase Ia Clinical Evaluation of the Safety and Immunogenicity of the Plasmodium falciparum Blood-Stage Antigen AMA1 in ChAd63 and MVA Vaccine Vectors
Traditionally, vaccine development against the blood-stage of Plasmodium falciparum infection has focused on recombinant protein-adjuvant formulations in order to induce high-titer growth-inhibitory antibody responses. However, to date no such vaccine encoding a blood-stage antigen(s) alone has induced significant protective efficacy against erythrocytic-stage infection in a pre-specified primary endpoint of a Phase IIa/b clinical trial designed to assess vaccine efficacy. Cell-mediated responses, acting in conjunction with functional antibodies, may be necessary for immunity against blood-stage P. falciparum. The development of a vaccine that could induce both cell-mediated and humoral immune responses would enable important proof-of-concept efficacy studies to be undertaken to address this question
Fusion of the Mycobacterium tuberculosis Antigen 85A to an Oligomerization Domain Enhances Its Immunogenicity in Both Mice and Non-Human Primates
To prevent important infectious diseases such as tuberculosis, malaria and HIV, vaccines inducing greater T cell responses are required. In this study, we investigated whether fusion of the M. tuberculosis antigen 85A to recently described adjuvant IMX313, a hybrid avian C4bp oligomerization domain, could increase T cell responses in pre-clinical vaccine model species. In mice, the fused antigen 85A showed consistent increases in CD4+ and CD8+ T cell responses after DNA and MVA vaccination. In rhesus macaques, higher IFN-Îł responses were observed in animals vaccinated with MVA-Ag85A IMX313 after both primary and secondary immunizations. In both animal models, fusion to IMX313 induced a quantitative enhancement in the response without altering its quality: multifunctional cytokines were uniformly increased and differentiation into effector and memory T cell subsets was augmented rather than skewed. An extensive in vivo characterization suggests that IMX313 improves the initiation of immune responses as an increase in antigen 85A specific cells was observed as early as day 3 after vaccination. This report demonstrates that antigen multimerization using IMX313 is a simple and effective cross-species method to improve vaccine immunogenicity with potentially broad applicability
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Hepcidin-mediated hypoferremia disrupts immune responses to vaccination and infection
Background: How specific nutrients influence adaptive immunity is of
broad interest. Iron deficiency is the most common micronutrient deficiency worldwide and imparts a significant burden of global disease;
however, its effects on immunity remain unclear.
Methods: We used a hepcidin mimetic and several genetic models to
examine the effect of low iron availability on T cells in vitro and on immune responses to vaccines and viral infection in mice. We examined
humoral immunity in human patients with raised hepcidin and low
serum iron caused by mutant TMPRSS6. We tested the effect of iron
supplementation on vaccination-induced humoral immunity in piglets,
a natural model of iron deficiency.
Findings: We show that low serum iron (hypoferremia), caused by
increased hepcidin, severely impairs effector and memory responses
to immunizations. The intensified metabolism of activated lymphocytes
requires the support of enhanced iron acquisition, which is facilitated by
IRP1/2 and TFRC. Accordingly, providing extra iron improved the
response to vaccination in hypoferremic mice and piglets, while
conversely, hypoferremic humans with chronically increased hepcidin
have reduced concentrations of antibodies specific for certain pathogens. Imposing hypoferremia blunted the T cell, B cell, and neutralizing
antibody responses to influenza virus infection in mice, allowing the virus to persist and exacerbating lung inflammation and morbidity.
Conclusions: Hypoferremia, a well-conserved physiological innate
response to infection, can counteract the development of adaptive immunity. This nutrient trade-off is relevant for understanding and
improving immune responses to infections and vaccines in the globally
common contexts of iron deficiency and inflammatory disorders
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers âŒ99% of the euchromatic genome and is accurate to an error rate of âŒ1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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A surgical anatomy training session improves knowledge and confidence in identifying anatomical structures among medical students on the surgical clerkship
Purpose
Recent trends in medical education have shifted towards earlier clinical experiences with reduced preclinical time, thereby decreasing didactic time for human anatomy prior to surgical rotations. Here we assess a dedicated program designed to teach relevant general surgery principles to students at the beginning of their surgical clerkship.
Methods
All medical students who rotated on the surgery clerkship from 2022 to 2023 at a single institution were included. Students voluntarily and anonymously completed identical assessments prior to, 24Â h after, and 10Â weeks after participating in a required 4-h in-person prosection-based anatomy session. The assessment was comprised of (1) written multiple-choice questions, (2) image-based multiple-choice questions using intraoperative photographs, and (3) confidence scoring utilizing a 5-point Likert scale.
Results
Pre-session and post-session and post-clerkship test survey completion rates were 52% (
n
â=â104), 27.5% (
n
â=â55), and 20% (
n
â=â30), respectively. Post-session and post-clerkship test written, image-based, and confidence scores were significantly higher than pre-test scores. Post-session and post-clerkship test scores were not different with the exception of written-based questions.
Conclusions
A focused general surgery anatomy session improves both written-based and image-based test performance as well as overall confidence in medical studentsâ understanding of surgical anatomy while completing the surgery clerkship. As medical school curricula continue to evolve with earlier clinical exposure at the expense of dedicated anatomy didactics, new methods that teach surgically relevant anatomy should continue to be explored to optimize medical education