Publications by authors named "Mandy Ng"

The direction of left-right visceral asymmetry is conserved in vertebrates. Deviations of the standard asymmetric pattern are rare, and the underlying mechanisms are not understood. Here, we use the teleost Astyanax mexicanus, consisting of surface fish with normal left-oriented heart asymmetry and cavefish with high levels of reversed right-oriented heart asymmetry, to explore natural changes in asymmetry determination.

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Purpose: To evaluate (1) the long-term efficacy of low-concentration atropine over 5 years, (2) the proportion of children requiring re-treatment and associated factors, and (3) the efficacy of pro re nata (PRN) re-treatment using 0.05% atropine from years 3 to 5.

Design: Randomized, double-masked extended trial.

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Article Synopsis
  • A study investigated how secondhand smoke (SHS) exposure affects the retinal blood vessels of children aged 6 to 8 years, revealing a link between SHS and wider arteriolar and venular calibers.
  • Data was collected through eye exams and questionnaires, and advanced technology was used to analyze retinal images in relation to smoking exposure.
  • The findings indicate that children in homes with smokers experience significant changes in their retinal vasculature, highlighting the negative health impact of secondhand smoke, but call for more thorough research on other influencing factors.
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Background: Unidirectional regeneration in the basal chordate Ciona intestinalis involves the proliferation of adult stem cells residing in the branchial sac vasculature and the migration of progenitor cells to the site of distal injury. However, after the Ciona body is bisected, regeneration occurs in the proximal but not in the distal fragments, even if the latter include a part of the branchial sac with stem cells. A transcriptome was sequenced and assembled from the isolated branchial sacs of regenerating animals, and the information was used to provide insights into the absence of regeneration in distal body fragments.

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Importance: Secondhand smoke (SHS) exposure potentially threatens ocular health; however, its association with myopia is unknown.

Objective: To examine the association between SHS exposure and childhood myopia.

Design, Setting, And Participants: Cross-sectional data from the population-based Hong Kong Children Eye Study were used.

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Importance: Childhood myopia increased during the COVID-19 pandemic. Limited evidence exists about whether myopia development was reversed or worsened after the lockdown.

Objective: To determine the prevalence of myopia and its associated factors before, during, and after COVID-19 restrictions.

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Importance: Early onset of myopia is associated with high myopia later in life, and myopia is irreversible once developed.

Objective: To evaluate the efficacy of low-concentration atropine eyedrops at 0.05% and 0.

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Combining left ventricular assist device (LVAD) implantation and longitudinal sleeve gastrectomy may enable patients with morbid obesity to lose enough weight for heart transplant eligibility. In a retrospective study, we evaluated long-term outcomes of patients with body mass indexes ≥35 who underwent LVAD implantation and longitudinal sleeve gastrectomy during the same hospitalization (from January 2013 through July 2018) and then adhered to a dietary protocol. We included 22 patients (mean age, 49.

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Article Synopsis
  • - The evolution of visceral organ asymmetry in vertebrates typically shows a consistent left-side bias for the heart and opposing side development for the pancreas and liver; however, this pattern can reverse in some species.
  • - In Astyanax mexicanus, cave-dwelling fish have developed changes in organ asymmetry, including the heart and liver, while surface-dwelling fish exhibit the conventional asymmetry.
  • - Research indicates that these changes in organ asymmetry in cavefish are influenced by maternal genetic effects, with differences in the expression of key signaling molecules affecting left-right patterning.
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Article Synopsis
  • Vestigial structures, like the reduced eyes in cave-dwelling fish, provide insights into evolutionary processes, but the development of these features is not well understood.
  • Research on Astyanax mexicanus reveals that while cavefish embryos start with eyes, they lose them due to the degeneration caused by mutated genes.
  • The study identifies the gene cystathionine ß-synthase a (cbsa) as crucial in this eye degeneration, affecting eye development by disrupting blood vessel formation and leading to issues like aneurysms.
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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019, causing a respiratory disease (coronavirus disease 2019, COVID-19) of varying severity in Wuhan, China, and subsequently leading to a pandemic. The transmissibility and pathogenesis of SARS-CoV-2 remain poorly understood. We evaluate its tissue and cellular tropism in human respiratory tract, conjunctiva, and innate immune responses in comparison with other coronavirus and influenza virus to provide insights into COVID-19 pathogenesis.

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A widely accepted model for the evolution of cave animals posits colonization by surface ancestors followed by the acquisition of adaptations over many generations. However, the speed of cave adaptation in some species suggests mechanisms operating over shorter timescales. To address these mechanisms, we used , a teleost with ancestral surface morphs (surface fish, SF) and derived cave morphs (cavefish, CF).

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Astyanax mexicanus consists of two forms, a sighted surface dwelling form (surface fish) and a blind cave-dwelling form (cavefish). Embryonic eyes are initially formed in cavefish but they are subsequently arrested in growth and degenerate during larval development. Previous lens transplantation studies have shown that the lens plays a central role in cavefish eye loss.

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Importance: Secondhand smoking is a risk to adult ocular health, but its effect on children's ocular development is not known.

Objective: To assess the association between choroidal thickness and secondhand smoking exposure in children.

Design, Setting, And Participants: Children aged 6 to 8 years were consecutively recruited from January 2016 to July 2017 from the population-based Hong Kong Children Eye Study at the Chinese University of Hong Kong Eye Centre.

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Despite causing regular seasonal epidemics with substantial morbidity, mortality and socioeconomic burden, there is still a lack of research into influenza B viruses (IBVs). In this study, we provide for the first time a systematic investigation on the tropism, replication kinetics and pathogenesis of IBVs in the human respiratory tract.Physiologically relevant explant cultures of human bronchus and lung, human airway organoids, and cultures of differentiated primary human bronchial epithelial cells and type-I-like alveolar epithelial cells were used to study the cellular and tissue tropism, replication competence and induced innate immune response of 16 IBV strains isolated from 1940 to 2012 in comparison with human seasonal influenza A viruses (IAVs), H1N1 and H3N2.

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Background: Healthcare workers (HCWs) use personal protective equipment (PPE) in Ebola virus disease (EVD) situations. However, preventing the contamination of HCWs and the environment during PPE removal crucially requires improved strategies. This study aimed to compare the efficacy of three PPE ensembles, namely, Hospital Authority (HA) Standard Ebola PPE set (PPE1), Dupont Tyvek Model, style 1422A (PPE2), and HA isolation gown for routine patient care and performing aerosol-generating procedures (PPE3) to prevent EVD transmission by measuring the degree of contamination of HCWs and the environment.

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Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has emerged as a coronavirus infection of humans in the past 5 years. Though confined to certain geographical regions of the world, infection has been associated with a case fatality rate of 35%, and this mortality may be higher in ventilated patients. As there are few readily available animal models that accurately mimic human disease, it has been a challenge to ethically determine what optimum treatment strategies can be used for this disease.

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Objective: To identify factors predicting falls and limited mobility in people with stroke at 12 months after returning home from rehabilitation.

Design: Observational cohort study with 12-month follow-up.

Setting: Community.

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Novel avian H7N9 virus emerged in China in 2013 resulting in a case fatality rate of around 39% and continues to pose zoonotic and pandemic risk. Amino acid substitutions in PB2 protein were shown to influence the pathogenicity and transmissibility of H7N9 following experimental infection of ferrets and mice. In this study, we evaluated the role of amino acid substitution PB2-627K or compensatory changes at PB2-591K and PB2-701N, on the tropism and replication competence of H7N9 viruses for human and swine respiratory tracts using ex vivo organ explant cultures.

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Highly pathogenic H5N1 viruses continue to transmit zoonotically, with mortality higher than 60%, and pose a pandemic threat. Antivirals remain the primary choice for treating H5N1 diseases and have their limitations. Encouraging findings highlight the beneficial effects of combined treatment of host targeting agents with immune-modulatory activities.

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Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of hospital- and community-associated infections. The formation of adherent clusters of cells known as biofilms is an important virulence factor in MRSA pathogenesis. Previous studies showed that subminimal inhibitory (sub-MIC) concentrations of methicillin induce biofilm formation in the community-associated MRSA strain LAC.

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