Publications by authors named "Joanne Chan"

Advances in multiplex mass spectrometry-based technologies have enabled high-throughput, quantitative proteome profiling of large cohort. However, certain experimental design configurations can amplify sample variability and introduce systematic biases. To address these challenges, we incorporated two novel features in a recent proteogenomic investigation: (1) the inclusion of two reference samples within each mass spectrometry run to serve as internal standards, and (2) the analysis of each specimen as technical replicates across two distinct mass spectrometry runs.

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Article Synopsis
  • Human immune responses to infections like malaria are influenced by genetics, environment, and past infections, but the role of latent cytomegalovirus (CMV) in malaria immunity is not well understood.
  • Research examined how CMV affects immune responses to malaria using samples from prior clinical trials, revealing that CMV seropositivity leads to lower production of specific antibodies after malaria infection and vaccination, and alters Tfh cell responses.
  • The study indicates that individuals with CMV are less likely to develop protective antibodies against malaria, highlighting the need for further research in malaria-endemic areas to understand how CMV might affect immunity in children.
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Familial adenomatous polyposis (FAP) is a genetic disease causing hundreds of premalignant polyps in affected persons and is an ideal model to study transitions of early precancer states to colorectal cancer (CRC). We performed deep multiomic profiling of 93 samples, including normal mucosa, benign polyps and dysplastic polyps, from six persons with FAP. Transcriptomic, proteomic, metabolomic and lipidomic analyses revealed a dynamic choreography of thousands of molecular and cellular events that occur during precancerous transitions toward cancer formation.

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Engineered nanoparticles (NPs) are extensively used in the food industry, yet safety concerns remain. The lack of validated methodologies is a bottleneck towards resolving this uncertainty. Hence, the current study aims to compare two cell models by examining the toxicological impacts of two food-relevant NPs (SiO and Ag) on intestinal epithelia using monolayer Caco-2 cells and full-thickness 3D tissue models of human small intestines (EpiIntestinal™).

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remains a significant foodborne pathogen globally with . Typhimurium presenting as a frequently occurring serovar. This study aimed to characterize 67 .

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Some synthetic dyes are fraudulently added into spices to appeal visually to consumers. Food regulations in several countries, including the United States, Australia, Japan and the European Union, strictly prohibit the use of unauthorised synthetic dyes in food. Nevertheless, illegal practices persist, where spices contaminated with potentially carcinogenic dyes have been documented, posing potential health risks to consumers.

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A total diet study is often used to evaluate a population's baseline dietary exposure to chemical hazards from across the diet. In 2021-2023, Singapore carried out a TDS, and this article presents an overview of the study design and methodological selections in Singapore's TDS, as well as its relevance to ensuring food safety. A food consumption survey was conducted on Singapore citizens and permanent residents, where food consumption patterns of the Singapore population were identified.

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In this study, an advanced ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed for quantifying ethoxyquin (EQ). The approach employed a distinctive antioxidant added extraction step designed to prevent ethoxyquin decomposition and maintain analytical precision. This method effectively determines residue levels of EQ in eggs, processed egg products, poultry muscle, salmon, and liquid milk.

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There is a need to study the characteristics of outbreaks via Singapore's outbreak surveillance system to understand and identify the gaps in food safety for targeted policy interventions due to the increasing trend in gastroenteritis outbreaks and consequential increase in foodborne-related deaths and economic burden on public health systems worldwide. A total of 171 gastroenteritis outbreaks were investigated in Singapore from January 2018 to December 2021. This study analyzed the annual trend of investigated gastroenteritis outbreaks, the proportion of outbreaks by implicated sources of food, and the proportion of the type of pathogens identified from human cases, food samples, and environmental swabs collected from outbreak investigations.

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Accurate methods for meat speciation and quantification are essential for ensuring the supply of safe and wholesome meat and composite products with animal origins to negate the potential associated hazards, aid classification of consignments at the import control system, and thwart food fraud committed for financial gain. To better enhance meat safety control and combat food fraud, this study developed two duplex real-time polymerase chain reaction (real-time PCR) systems specifically designed for chicken, pork, sheep, and beef, using single-copy, chromosomally encoded, species-specific gene sequences to accurately measure the content of each meat type in meat products. DNA extracted from the raw and boiled reference materials prepared in varying proportions (ranging from 1% to 75%) were used in the development of the duplex assay to derive calibration factors to determine the meat content in different meat products.

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Background: Individuals with cancer are being given increasing responsibility for the self-management of their health and illness. In other chronic diseases, individuals who experience treatment burden are at risk of poorer health outcomes. Less is known about treatment burden and its impact on individuals with cancer.

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The objective of this study was to characterize the complement-inhibiting activity of SAR445088, a novel monoclonal antibody specific for the active form of C1s. Wieslab® and hemolytic assays were used to demonstrate that SAR445088 is a potent, selective inhibitor of the classical pathway of complement. Specificity for the active form of C1s was confirmed in a ligand binding assay.

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Rapid and robust detection assays for Enteritidis (SE) in shell eggs are essential to enable a quick testing turnaround time (TAT) at the earliest checkpoint and to ensure effective food safety control. Real-time polymerase chain reaction (qPCR) assays provide a workaround for the protracted lead times associated with conventional diagnostic testing. However, DNA-based analysis cannot reliably discriminate between signals from viable and dead bacteria.

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Existing systematic reviews have insufficiently delineated the differing cardiac and renal profile of ultrafiltration compared to diuretics as a method of decongestion in acute decompensated heart failure. This meta-analysis will investigate the impact of ultrafiltration compared to diuretics on prognostic cardiac and renal biomarkers. We searched PubMed Central, Ovid MEDLINE, Ovid Embase, all EBM reviews, and Web of Science Core Collection for randomised controlled trials published before 21 July 2022.

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Dysregulated activation of the complement system is implicated in the onset or progression of several diseases. Most clinical-stage complement inhibitors target the inactive complement proteins present at high concentrations in plasma, which increases target-mediated drug disposition and necessitates high drug levels to sustain therapeutic inhibition. Furthermore, many efforts are aimed at inhibiting only terminal pathway activity, which leaves opsonin-mediated effector functions intact.

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The consumption of processed foods is increasingly widespread and could have an impact on diet quality and health. Understanding the factors influencing people's eating habits is useful for assessing such impact. There are limited data on the consumption patterns of processed foods and associated factors influencing the dietary patterns in Singapore.

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T-follicular helper (Tfh) cells are key drivers of antibodies that protect from malaria. However, little is known regarding the host and parasite factors that influence Tfh and functional antibody development. Here, we use samples from a large cross-sectional study of children residing in an area of high malaria transmission in Uganda to characterize Tfh cells and functional antibodies to multiple parasites stages.

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Introduction: Understanding the human immune response to gametocytes and its association with gametocytemia is essential for understanding the transmission of malaria as well as progressing transmission blocking vaccine candidates.

Methods: In a multi-national clinical efficacy trial of artemisinin therapies (13 sites of varying transmission over South-East Asia and Africa), we measured Immunoglobulin G (IgG) responses to recombinant gametocyte antigens expressed on the gametocyte plasma membrane and leading transmission blocking vaccine candidates s230 (s230c and s230D1M) and s48/45 at enrolment in 1,114 participants with clinical falciparum malaria. Mixed effects linear and logistic regression were used to determine the association between gametocyte measures (gametocytemia and gametocyte density) and antibody outcomes at enrolment.

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Infection with Plasmodium falciparum parasites results in approximately 627,000 deaths from malaria annually. Key to the parasite's success is their ability to invade and subsequently grow within human erythrocytes. Parasite proteins involved in parasite invasion and proliferation are therefore intrinsically of great interest, as targeting these proteins could provide novel means of therapeutic intervention.

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The micronucleus (MN) assay is widely used as part of a battery of tests applied to evaluate the genotoxic potential of chemicals, including new food additives and novel food ingredients. Micronucleus assays typically utilise homogenous in vitro cell lines which poorly recapitulate the physiology, biochemistry and genomic events in the gut, the site of first contact for ingested materials. Here we have adapted and validated the MN endpoint assay protocol for use with complex 3D reconstructed intestinal microtissues; we have named this new protocol the reconstructed intestine micronucleus cytome (RICyt) assay.

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Background: Protective malarial antibodies are acquired more rapidly in adults than children, independently of cumulative exposure, however the cellular responses mediating these differences are unknown. CD4 T-follicular helper (Tfh) cells have key roles in inducing antibodies, with Th2-Tfh cell activation associated with antibody development in malaria. Whether Tfh cell activation in malaria is age dependent is unknown and no studies have compared Tfh cell activation in children and adults with malaria.

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Background: There is a clear need for novel approaches to malaria vaccine development. We aimed to develop a genetically attenuated blood-stage vaccine and test its safety, infectivity, and immunogenicity in healthy volunteers. Our approach was to target the gene encoding the knob-associated histidine-rich protein (KAHRP), which is responsible for the assembly of knob structures at the infected erythrocyte surface.

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Introduction: A vaccine would greatly accelerate current global efforts toward malaria elimination. While a partially efficacious vaccine has been achieved for , a major bottleneck in developing highly efficacious vaccines is a lack of reliable correlates of protection, and the limited application of assays that quantify functional immune responses to evaluate and down-select vaccine candidates in pre-clinical studies and clinical trials.

Areas Covered: In this review, we describe the important role of antibodies in immunity against malaria and detail the nature and functional activities of antibodies against the malaria-causing parasite.

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