Publications by authors named "Jason Kwan"

Microbial symbionts associate with multicellular organisms on a continuum from facultative associations to mutual codependency. In the oldest intracellular symbioses there is exclusive vertical symbiont transmission, and co-diversification of symbiotic partners over millions of years. Such symbionts often undergo genome reduction due to low effective population sizes, frequent population bottlenecks, and reduced purifying selection.

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The rapid expansion of multi-omics data has transformed biological research, offering unprecedented opportunities to explore complex genomic relationships across diverse organisms. However, the vast volume and heterogeneity of these datasets presents significant challenges for analyses. Here we introduce SocialGene, a comprehensive software suite designed to collect, analyze, and organize multi-omics data into structured knowledge graphs, with the ability to handle small projects to repository-scale analyses.

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Article Synopsis
  • An immunocompetent male from the Democratic Republic of Congo presented with fever and a rash, raising suspicion for Mpox due to current epidemiological trends.
  • After testing, he was diagnosed with primary varicella zoster virus (pVZV) using PCR from a lesion sample.
  • The patient recovered fully with supportive care, highlighting the need for careful differentiation among common viral rashes in medical settings.
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  • Microbial symbionts can form various types of relationships with multicellular organisms, ranging from optional partnerships to essential dependencies, with some examples showing long-term evolution and genome changes over millions of years.
  • In a study of Lagriinae beetles, researchers identified multiple occurrences of defensive symbionts that produce the antifungal compound lagriamide, despite no evidence of co-evolution or shared ancestry among them.
  • The findings suggest these symbionts independently evolved and lost parts of their genomes while specializing in producing lagriamide, which is crucial for protecting the beetles’ eggs and larvae from harmful fungi.
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Microorganisms from the order Burkholderiales have been the source of a number of important classes of natural products in recent years. For example, study of the beetle-associated symbiont led to the discovery of the antifungal polyketide lagriamide; an important molecule from the perspectives of both biotechnology and chemical ecology. As part of a wider project to sequence Burkholderiales genomes from our in-house Burkholderiales library we identified a strain containing a biosynthetic gene cluster (BGC) similar to the original lagriamide BGC.

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  • Microbialites, which are layered structures formed by microbial mats, are abundant in the fossil record and are currently being identified worldwide, presenting a challenge for understanding their formation and environmental functions.
  • Researchers conducted a study on living stromatolites in South Africa, collecting samples from various locations to analyze the composition and small molecule production of microbial communities using advanced techniques like gene sequencing and metabolomics.
  • The study identified a new group of metabolites called ibhayipeptolides, highlighting the diverse chemistry present in these microbialites and paving the way for future research on their roles and functions in the environment.
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  • * Researchers used a gene therapy approach with a specific virus to increase levels of trimeric APN in the liver of 5xFAD mice, which led to higher APN levels in the brain and reduced harmful amyloid-beta proteins.
  • * Treatment with APN gene therapy improved memory and reduced inflammation by lowering certain inflammatory markers in the mice, suggesting a promising potential therapy for Alzheimer's disease.
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Objective: Differences in the extent to which religious and scientific perspectives inform individuals' understanding of the world may affect their health and well-being. Yet minimal research has examined the influence of religious or scientific (or their relative influences) on health-related resources, behaviors, well-being, and stress responses, the focus of the current study.

Methods: A national sample of 289 U.

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Neuromyelitis optica spectrum disorders (NMOSD) are inflammatory autoimmune disorders of the CNS. IgG autoantibodies targeting the aquaporin-4 water channel (AQP4-IgGs) are the pathogenic effector of NMOSD. Dysregulated T follicular helper (Tfh) cells have been implicated in loss of B cell tolerance in autoimmune diseases.

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Invertebrates, particularly sponges, have been a dominant source of new marine natural products. For example, lasonolide A (LSA) is a potential anticancer molecule isolated from the marine sponge sp., with nanomolar growth inhibitory activity and a unique cytotoxicity profile against the National Cancer Institute 60-cell-line screen.

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  • Evaluating metagenomic software is crucial for enhancing the interpretation of metagenomes, and the CAMI II challenge focused on this by using complex datasets from numerous genomes and plasmids.
  • The analysis of 5,002 results from 76 software versions showed significant advancements in assembly, especially with long-read data, although challenges remained with related strains and genome recovery.
  • Findings indicated that while taxon profilers improved, they struggled with viruses and Archaea, highlighting the need for better reproducibility in clinical pathogen detection and guiding researchers in method selection based on efficiency and performance metrics.
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  • The COVID-19 pandemic highlights the risks that novel coronaviruses pose to human health, particularly focusing on the spike protein, which is crucial for viral entry into host cells.
  • The interaction between the spike protein and the ACE2 receptor, along with host proteases, is essential for the efficient infection process and the neutralization of the virus by antibodies.
  • The study also examines mutations in the SARS-CoV-2 variants that affect viral entry, and discusses the Canyon Hypothesis to explain the evolutionary changes in these viral proteins amid ongoing transmission.
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  • The earliest marine sponges likely appeared during the Cambrian explosion and may have formed symbiotic relationships with microbes even earlier in their extinct ancestors.
  • New research added 11 genomes to a specific bacterial order and identified a new family, revealing functional differences between three families of sponge-associated symbionts and their associations with low-microbial abundance (LMA) and high-microbial abundance (HMA) sponges.
  • The study highlights that symbionts tend to be specialized for their sponge hosts, showing that these relationships may have evolved through multiple association events rather than just from a single origin.
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New cyanobacteria-derived bifunctional analogues of doscadenamide A, a LasR-dependent quorum sensing (QS) activator in , characterized by dual acylation of the pyrrolinone core structure and the pendant side chain primary amine to form an imide/amide hybrid are reported. The identities of doscadenamides B-J were confirmed through total synthesis and a strategic focused library with different acylation and unsaturation patterns was created. Key molecular interactions for binding with LasR and a functional response through mutation studies coupled with molecular docking were identified.

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Stromatolites are complex microbial mats that form lithified layers. Fossilized stromatolites are the oldest evidence of cellular life on Earth, dating back over 3.4 billion years.

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Many animal phyla have no representatives within the catalog of whole metazoan genome sequences. This dataset fills in one gap in the genome knowledge of animal phyla with a draft genome of Bugula neritina (phylum Bryozoa). Interest in this species spans ecology and biomedical sciences because B.

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Restrictions imposed by the COVID-19 pandemic have required medical educators to reimagine almost every aspect of undergraduate medical training, including curriculum delivery and assessments in a short timeline. In this personal view article, executive members of the University of Toronto medical student government and Faculty leads of pre-clerkship and clerkship education highlight five practical ways in which a student-Faculty partnership enabled the rapid and smooth adaptation of curricula during the COVID-19 pandemic. These included involving students as partners in decision making to contribute learner perspectives early, agile and collaborative meeting structures, frequent and consistent communication with the student body, providing learners with Faculty perspectives from the frontlines, and striking a balance in the level of feedback collected from students.

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Background: Neuromyelitis optica spectrum disorders (NMOSD) are central nervous system (CNS) autoimmune inflammatory demyelinating diseases characterized by recurrent episodes of acute optic neuritis and transverse myelitis. Aquaporin-4 immunoglobulin G (AQP4-IgG) autoantibodies, which target the water channel aquaporin-4 (AQP4) on astrocytic membrane, are pathogenic in NMOSD. Glutamate excitotoxicity, which is triggered by internalization of AQP4-glutamate transporter complex after AQP4-IgG binding to astrocytes, is involved in early NMOSD pathophysiologies.

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Improving the clinical translation of animal-based neural stem/progenitor cell (NSPC) therapies to humans requires an understanding of intrinsic human and animal cell characteristics. We report a novel method to assess spinal cord NSPCs from a small (rodent) and large (porcine) animal model in comparison to human NSPCs. To extract live adult human, porcine, and rodent spinal cord tissue, we illustrate a strategy using an anterior or posterior approach that was simulated in a porcine model.

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Circulating adiponectin (APN) levels decrease with age and obesity. On the other hand, a reduction in APN levels is associated with neurodegeneration and neuroinflammation. We previously showed that aged adiponectin knockout (APN) mice developed Alzheimer's like pathologies, cerebral insulin resistance, and cognitive impairments.

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Symbiotic mutualisms of bacteria and animals are ubiquitous in nature, running a continuum from facultative to obligate from the perspectives of both partners. The loss of functions required for living independently but not within a host gives rise to reduced genomes in many symbionts. Although the phenomenon of genome reduction can be explained by existing evolutionary models, the initiation of the process is not well understood.

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Quorum sensing (QS) plays a critical role in the regulation of bacterial pathogenesis. Doscadenamide A () was isolated from a marine cyanobacterium, its structure elucidated by NMR, and its activity linked to QS induction. The total synthesis of was developed, and the absolute configuration confirmed through comparison of the isolated natural product with synthetic diastereomers.

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Background: Microglia-mediated neuroinflammation is important in Alzheimer's disease (AD) pathogenesis. Extracellular deposition of β-amyloid (Aβ), a major pathological hallmark of AD, can induce microglia activation. Adiponectin (APN), an adipocyte-derived adipokine, exerts anti-inflammatory effects in the periphery and brain.

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DNA sequencing of a large collection of bacterial genomes reveals a wealth of orphan biosynthetic gene clusters (BGCs) with no identifiable products. BGC silencing, for those orphan clusters that are truly silent, rather than those whose products have simply evaded detection and cluster correlation, is postulated to result from transcriptional inactivation of these clusters under standard laboratory conditions. Here, we employ a multi-omics approach to demonstrate how interspecies interactions modulate the keyicin producing kyc cluster at the transcriptome level in cocultures of kyc-bearing Micromonospora sp.

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Article Synopsis
  • Shotgun metagenomics allows researchers to study microbial communities directly in their environments, but it requires a process called 'binning' to achieve species-level resolution.
  • Existing binning methods face challenges with eukaryotic contamination and complex single metagenomes, necessitating more effective automated solutions.
  • The newly developed 'Autometa' pipeline addresses these issues by integrating various genomic factors to accurately separate microbial genomes from contaminants, enabling the analysis of over 1000 genomes from complex metagenomic samples.
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