Publications by authors named "Joanne Lau"

Chikungunya virus (CHIKV) is a re-emerging mosquito-borne virus, which causes epidemics of fever, joint pain and rash. There are three genotypes: West African, East/Central/South/Africa (ECSA) and Asian, with the latter two predominant globally. Genotype-specific differences in clinical presentations, virulence and immunopathology have been described.

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Introduction: Vestibular migraine (VM) is a common condition; individuals experience dizziness with migraine symptoms. Vestibular rehabilitation therapy (VRT) has been reported as an effective treatment for VM, however, evidence is limited. VM and traumatic brain injury (TBI) can co-occur, and some suggest that TBI can induce VM.

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The phenotype of glioma-initiating cells (GIC) is modulated by cell-intrinsic and cell-extrinsic factors. Phenotypic heterogeneity and plasticity of GIC is an important limitation to therapeutic approaches targeting cancer stem cells. Plasticity also presents a challenge to the identification, isolation, and propagation of purified cancer stem cells.

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Background: Available data on influenza burden across Southeast Asia are largely limited to pediatric populations, with inconsistent findings.

Methods: We conducted a multicenter, hospital-based active surveillance study of adults in Malaysia with community-acquired pneumonia (CAP), acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and acute exacerbation of asthma (AEBA), who had influenza-like illness ≤10 days before hospitalization. We estimated the rate of laboratory-confirmed influenza and associated complications over 13 months (July 2018-August 2019) and described the distribution of causative influenza strains.

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Intractable epilepsy remains a significant medical challenge, resulting in recurrent and prolonged intensive care unit (ICU) admissions. Autoimmune encephalitis is emerging as a treatable cause of intractable epilepsy. It is characterized by antibodies against cerebral antigens, such as potassium channels such as leucine-rich, glioma inactivated 1 (LGI1) and contactin-associated protein 2 (CASPR2), calcium channels such as the voltage-gated calcium channel (VGCC), or neurotransmitter receptors such as the -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), gamma aminobutyric acid receptor (GABAR), and -methyl-D-aspartate receptor (NMDAR).

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Human astrocytomas and oligodendrogliomas are defined by mutations of the metabolic enzymes isocitrate dehydrogenase (IDH) 1 or 2, resulting in the production of the abnormal metabolite D-2 hydroxyglutarate. Here, we studied the effect of mutant IDH on cell proliferation and apoptosis in a glioma mouse model. Tumors were generated by inactivating and in forebrain progenitors and compared with tumors additionally expressing the Idh1 R132H mutation.

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Chorionic villus sampling (CVS), routinely used for prenatal diagnosis of cytogenetic disorders, also possesses great potential for the study of placentation. To better understand villus biology, human placentation, and how these relate to pregnancy outcomes, we examined the morphology and transcriptomes of villi obtained via CVS from 10 to 14 weeks of pregnancy and correlated these with pregnancy attributes and clinical outcomes. First, we established a morphological scoring system based on three main villus features: branching, budding and vascularization.

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To identify biomarkers for glioma growth, invasion and progression, we used a candidate gene approach in mouse models with two complementary brain tumour phenotypes, developing either slow-growing, diffusely infiltrating gliomas or highly proliferative, non-invasive primitive neural tumours. In a microRNA screen we first identified microRNA-449a as most significantly differentially expressed between these two tumour types. miR-449a has a target dependent effect, inhibiting cell growth and migration by downregulation of CCND1 and suppressing neural phenotypes by inhibition of G protein coupled-receptor (GPR) 158.

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Cardiac sarcoidosis (CS) can cause atrial and ventricular arrhythmias, conduction system disease, and congestive heart failure. The use of advanced imaging modalities including cardiac magnetic resonance and positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose can be helpful in evaluating the extent of disease and response to treatment. The management of CS patients can be challenging, requiring immunosuppression medications, antiarrhythmic drugs, implantable cardiac devices, and cardiac ablation procedures.

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Many studies support the pro-nociceptive role of brain-derived neurotrophin factor (BDNF) in pain processes in the peripheral and central nervous system. We have previously shown that nociceptor-derived BDNF is involved in inflammatory pain. Microglial-derived BDNF has also been shown to be involved in neuropathic pain.

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Objective: To assess the trajectory of perioperative brain growth in relationship to cardiac diagnosis and acquired brain injuries.

Methods: This was a cohort study of term neonates with hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (d-TGA). Subjects underwent magnetic resonance imaging of the brain pre- and postoperatively to determine the severity of brain injury and total and regional brain volumes by the use of automated morphometry.

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Targeted cell- or region-specific gene recombination is widely used in the functional analysis of genes implicated in development and disease. In the brain, targeted gene recombination has become a mainstream approach to study neurodegeneration or tumorigenesis. The use of the Cre-loxP system to study tumorigenesis in the adult central nervous system (CNS) can be limited, when the promoter (such as GFAP) is also transiently expressed during development, which can result in the recombination of progenies of different lineages.

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This case highlights the diagnostic challenges in patients presenting with bilateral sudden sensorinueral hearing loss (SNHL). The aetiology of bilateral sudden SNHL may span several medical disciplines. Therefore, clinicians should be mindful of such presentations, and consider aetiologies beyond otological and neurological causes.

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The response regulator CpdR couples phosphorylation events in Caulobacter crescentus with the AAA+ protease ClpXP to provide punctuated degradation of crucial substrates involved in cell cycle regulation. CpdR functions like an adaptor to alter substrate choice by ClpXP; however, it remains unclear how CpdR influences its multiple targets. Here we show that, unlike canonical ClpXP adaptors, CpdR alone does not strongly bind its substrate.

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Clostridium phytofermentans was isolated from forest soil and is distinguished by its capacity to directly ferment plant cell wall polysaccharides into ethanol as the primary product, suggesting that it possesses unusual catabolic pathways. The objective of the present study was to understand the molecular mechanisms of biomass conversion to ethanol in a single organism, Clostridium phytofermentans, by analyzing its complete genome and transcriptome during growth on plant carbohydrates. The saccharolytic versatility of C.

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Aim: This study aimed to assess the association between Tai Chi and sleep quality in middle-aged Tai Chi practitioners.

Methods: This cross-sectional descriptive study recruited a convenience sample of 250 middle-aged Tai Chi practitioners. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI).

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We have created a library of 2007 mutagenized Caenorhabditis elegans strains, each sequenced to a target depth of 15-fold coverage, to provide the research community with mutant alleles for each of the worm's more than 20,000 genes. The library contains over 800,000 unique single nucleotide variants (SNVs) with an average of eight nonsynonymous changes per gene and more than 16,000 insertion/deletion (indel) and copy number changes, providing an unprecedented genetic resource for this multicellular organism. To supplement this collection, we also sequenced 40 wild isolates, identifying more than 630,000 unique SNVs and 220,000 indels.

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Geobacter sulfurreducens can form electrically conductive biofilms, but the potential for conductivity through mixed-species biofilms has not been examined. A current-producing biofilm grown from a wastewater sludge inoculum was highly conductive with low charge transfer resistance even though microorganisms other than Geobacteraceae accounted for nearly half the microbial community.

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Background: Tissue-specific gene deletion has proved informative in the analysis of pain pathways. Advillin has been shown to be a pan-neuronal marker of spinal and cranial sensory ganglia. We generated BAC transgenic mice using the Advillin promoter to drive a tamoxifen-inducible CreERT2 recombinase construct in order to be able to delete genes in adult animals.

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ΔNp63α is a critical pro-survival protein overexpressed in 80% of head and neck squamous cell carcinomas (HNSCCs) where it inhibits TAp73β transcription of p53-family target genes, which is thought to increase HNSCC resistance to chemotherapy-induced cell death. However, the mechanisms governing ΔNp63α function are largely unknown. In this study, we identify special AT-rich-binding protein 2 (SATB2) as a new ΔNp63α-binding protein that is preferentially expressed in advanced-stage primary HNSCC and show that SATB2 promotes chemoresistance by enhancing ΔNp63α-mediated transrepression by augmenting ΔNp63α engagement to p53-family responsive elements.

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Background: Anaemia is a common complication of chronic kidney disease. A number of studies have identified an adverse association between haemoglobin (Hgb) variability and mortality. To date, no study has evaluated the impact of Hgb variability on mortality in the setting of a uniform Hgb target and erythropoiesis-stimulating agents (ESA) dosing strategy.

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Hexamethylene bis-acetamide inducible protein 1 (HEXIM1) is an inhibitor of the positive transcription elongation factor b (P-TEFb), which controls RNA polymerase II transcription and human immunodeficiency virus Tat transactivation. In cells, more than half of P-TEFb is associated with HEXIM1 resulting in the inactivation of P-TEFb. Recently, we found that nucleophosmin (NPM), a key factor involved in p53 signaling pathway, interacts with HEXIM1 and activates P-TEFb-dependent transcription.

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The detection of 19 norandrosterone (19-NA) in a competitor's urine sample is taken as prima facie evidence of administration of nandrolone or other 19-norsteroid but a potential problem is that administration of norethisterone, a progestogen used for menstrual disorders and for hormonal contraception, also results in the excretion of 19-NA that can exceed the laboratory reporting threshold of 2ng/mL. The contribution of norethisterone to urinary 19-NA with and without 19-norandrostenedione, a known norethisterone tablet impurity, requires evaluation. Preparations containing, either <2ng or 1microg 19-norandrostenedione impurity per 5mg of norethisterone, administered to female volunteers (n=10) in doses comparable to those used for menstrual disorders (5mg three times daily for 10 days), resulted in maximal 19-NA concentrations of 51 and 63ng/mL, respectively.

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The finding of measurable amounts of 19-norandrostenedione in norethisterone tablets prompted us to develop an assay to quantify this steroid. 19-Norandrostenedione is an anabolic steroid whose use in sport is prohibited by the World Anti-Doping Agency (WADA). The assay was developed using isotope dilution and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantification of 19-norandrostenedione in norethisterone formulations, with [3,4-(13)C(2)]-19-norandrostenedione as the internal standard.

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19-Norandrosterone (19-NA) is the principal urinary metabolite of the anabolic steroid nandrolone and its prohormones. The administration of these 19-nor androgens is prohibited in sport by the World Anti-Doping Agency (WADA) but, even so, adverse findings for 19-NA continue to be commonly reported. Little is known about the urinary concentrations of 19-NA that can occur in women who are not using anabolic steroids, including those using oral contraceptives containing the 19-nor progestogen norethisterone.

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