36 results on '"Low JY"'
Search Results
2. Review on demulsification techniques for oil/water emulsion: Comparison of recyclable and irretrievable approaches.
- Author
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Low JY, Khe CS, Usman F, Hassan YM, Lai CW, You KY, Lim JW, and Khoo KS
- Subjects
- Emulsions chemistry, Emulsifying Agents, Natural Resources, Petroleum, Nanoparticles
- Abstract
Since the establishment of the first global refinery in 1856, crude oil has remained one of the most lucrative natural resources worldwide. However, during the extraction process from reservoirs, crude oil gets contaminated with sediments, water, and other impurities. The presence of pressure, shear forces, and surface-active compounds in crude oil leads to the formation of unwanted oil/water emulsions. These emulsions can take the form of water-in-oil (W/O) emulsions, where water droplets disperse continuously in crude oil, or oil-in-water (O/W) emulsions, where crude oil droplets are suspended in water. To prevent the spread of water and inorganic salts, these emulsions need to be treated and eliminated. In existing literature, different demulsification procedures have shown varying outcomes in effectively treating oil/water emulsions. The observed discrepancies have been attributed to various factors such as temperature, salinity, pH, droplet size, and emulsifier concentrations. It is crucial to identify the most effective demulsification approach for oil/water separation while adhering to environmental regulations and minimizing costs for the petroleum sector. Therefore, this study aims to explore and review recent advancements in two popular demulsification techniques: chemical demulsification and magnetic nanoparticles-based (MNP) demulsification. The advantages and disadvantages of each technique are assessed, with the magnetic approach emerging as the most promising due to its desirable efficiency and compliance with environmental and economic concerns. The findings of this report are expected to have a significant impact on the overall process of separating oil and water, benefiting the oil and gas industry, as well as other relevant sectors in achieving the circular economy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2024
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3. Characterization of HOXB13 expression patterns in localized and metastatic castration-resistant prostate cancer.
- Author
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Patel RA, Sayar E, Coleman I, Roudier MP, Hanratty B, Low JY, Jaiswal N, Ajkunic A, Dumpit R, Ercan C, Salama N, O'Brien VP, Isaacs WB, Epstein JI, De Marzo AM, Trock BJ, Luo J, Brennen WN, Tretiakova M, Vakar-Lopez F, True LD, Goodrich DW, Corey E, Morrissey C, Nelson PS, Hurley PJ, Gulati R, and Haffner MC
- Subjects
- Animals, Humans, Male, Mice, Genes, Homeobox, Homeodomain Proteins genetics, Homeodomain Proteins metabolism, Prostate pathology, Transcription Factors genetics, Transcription Factors metabolism, United Kingdom, Prostatic Neoplasms pathology, Prostatic Neoplasms, Castration-Resistant metabolism
- Abstract
HOXB13 is a key lineage homeobox transcription factor that plays a critical role in the differentiation of the prostate gland. Several studies have suggested that HOXB13 alterations may be involved in prostate cancer development and progression. Despite its potential biological relevance, little is known about the expression of HOXB13 across the disease spectrum of prostate cancer. To this end, we validated a HOXB13 antibody using genetic controls and investigated HOXB13 protein expression in murine and human developing prostates, localized prostate cancers, and metastatic castration-resistant prostate cancers. We observed that HOXB13 expression increases during later stages of murine prostate development. All localized prostate cancers showed HOXB13 protein expression. Interestingly, lower HOXB13 expression levels were observed in higher-grade tumors, although no significant association between HOXB13 expression and recurrence or disease-specific survival was found. In advanced metastatic prostate cancers, HOXB13 expression was retained in the majority of tumors. While we observed lower levels of HOXB13 protein and mRNA levels in tumors with evidence of lineage plasticity, 84% of androgen receptor-negative castration-resistant prostate cancers and neuroendocrine prostate cancers (NEPCs) retained detectable levels of HOXB13. Notably, the reduced expression observed in NEPCs was associated with a gain of HOXB13 gene body CpG methylation. In comparison to the commonly used prostate lineage marker NKX3.1, HOXB13 showed greater sensitivity in detecting advanced metastatic prostate cancers. Additionally, in a cohort of 837 patients, 383 with prostatic and 454 with non-prostatic tumors, we found that HOXB13 immunohistochemistry had a 97% sensitivity and 99% specificity for prostatic origin. Taken together, our studies provide valuable insight into the expression pattern of HOXB13 during prostate development and cancer progression. Furthermore, our findings support the utility of HOXB13 as a diagnostic biomarker for prostate cancer, particularly to confirm the prostatic origin of advanced metastatic castration-resistant tumors. © 2023 The Pathological Society of Great Britain and Ireland., (© 2023 The Pathological Society of Great Britain and Ireland.)
- Published
- 2024
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4. MYC is a regulator of androgen receptor inhibition-induced metabolic requirements in prostate cancer.
- Author
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Crowell PD, Giafaglione JM, Jones AE, Nunley NM, Hashimoto T, Delcourt AML, Petcherski A, Agrawal R, Bernard MJ, Diaz JA, Heering KY, Huang RR, Low JY, Matulionis N, Navone NM, Ye H, Zoubeidi A, Christofk HR, Rettig MB, Reiter RE, Haffner MC, Boutros PC, Shirihai OS, Divakaruni AS, and Goldstein AS
- Subjects
- Humans, Male, Androgens metabolism, Cell Line, Tumor, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, Receptors, Androgen drug effects, Receptors, Androgen metabolism, Signal Transduction, Prostatic Neoplasms genetics, Prostatic Neoplasms, Castration-Resistant genetics
- Abstract
Advanced prostate cancers are treated with therapies targeting the androgen receptor (AR) signaling pathway. While many tumors initially respond to AR inhibition, nearly all develop resistance. It is critical to understand how prostate tumor cells respond to AR inhibition in order to exploit therapy-induced phenotypes prior to the outgrowth of treatment-resistant disease. Here, we comprehensively characterize the effects of AR blockade on prostate cancer metabolism using transcriptomics, metabolomics, and bioenergetics approaches. The metabolic response to AR inhibition is defined by reduced glycolysis, robust elongation of mitochondria, and increased reliance on mitochondrial oxidative metabolism. We establish DRP1 activity and MYC signaling as mediators of AR-blockade-induced metabolic phenotypes. Rescuing DRP1 phosphorylation after AR inhibition restores mitochondrial fission, while rescuing MYC restores glycolytic activity and prevents sensitivity to complex I inhibition. Our study provides insight into the regulation of treatment-induced metabolic phenotypes and vulnerabilities in prostate cancer., Competing Interests: Declaration of interests P.C.B. sits on the scientific advisory boards of Sage Bionetworks, BioSymetrics, Inc., and Intersect Diagnostics, Inc., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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5. Reversible epigenetic alterations mediate PSMA expression heterogeneity in advanced metastatic prostate cancer.
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Sayar E, Patel RA, Coleman IM, Roudier MP, Zhang A, Mustafi P, Low JY, Hanratty B, Ang LS, Bhatia V, Adil M, Bakbak H, Quigley DA, Schweizer MT, Hawley JE, Kollath L, True LD, Feng FY, Bander NH, Corey E, Lee JK, Morrissey C, Gulati R, Nelson PS, and Haffner MC
- Subjects
- Male, Humans, Treatment Outcome, Prostate-Specific Antigen, Histone Deacetylase Inhibitors, Prostatic Neoplasms, Castration-Resistant metabolism
- Abstract
Prostate-specific membrane antigen (PSMA) is an important cell surface target in prostate cancer. There are limited data on the heterogeneity of PSMA tissue expression in metastatic castration-resistant prostate cancer (mCRPC). Furthermore, the mechanisms regulating PSMA expression (encoded by the FOLH1 gene) are not well understood. Here, we demonstrate that PSMA expression is heterogeneous across different metastatic sites and molecular subtypes of mCRPC. In a rapid autopsy cohort in which multiple metastatic sites per patient were sampled, we found that 13 of 52 (25%) cases had no detectable PSMA and 23 of 52 (44%) cases showed heterogeneous PSMA expression across individual metastases, with 33 (63%) cases harboring at least 1 PSMA-negative site. PSMA-negative tumors displayed distinct transcriptional profiles with expression of druggable targets such as MUC1. Loss of PSMA was associated with epigenetic changes of the FOLH1 locus, including gain of CpG methylation and loss of histone 3 lysine 27 (H3K27) acetylation. Treatment with histone deacetylase (HDAC) inhibitors reversed this epigenetic repression and restored PSMA expression in vitro and in vivo. Collectively, these data provide insights into the expression patterns and regulation of PSMA in mCRPC and suggest that epigenetic therapies - in particular, HDAC inhibitors - can be used to augment PSMA levels.
- Published
- 2023
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6. Genomic Characterization of Prostatic Basal Cell Carcinoma.
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Low JY, Ko M, Hanratty B, Patel RA, Bhamidipati A, Heaphy CM, Sayar E, Lee JK, Li S, De Marzo AM, Nelson WG, Gupta A, Yegnasubramanian S, Ha G, Epstein JI, and Haffner MC
- Subjects
- Male, Humans, Prostate pathology, Genomics, Receptor-Like Protein Tyrosine Phosphatases, Class 2, Guanine Nucleotide Exchange Factors, Prostatic Neoplasms genetics, Prostatic Neoplasms pathology, Carcinoma, Basal Cell genetics, Carcinoma, Basal Cell pathology, Skin Neoplasms pathology
- Abstract
Basal cell carcinoma (BCC) of the prostate is a rare tumor. Compared with the more common acinar adenocarcinoma (AAC) of the prostate, BCCs show features of basal cell differentiation and are thought to be biologically distinct from AAC. The spectrum of molecular alterations of BCC has not been comprehensively described, and genomic studies are lacking. Herein, whole genome sequencing was performed on archival formalin-fixed, paraffin-embedded specimens of two cases with BCC. Prostatic BCCs were characterized by an overall low copy number and mutational burden. Recurrent copy number loss of chromosome 16 was observed. In addition, putative driver gene alterations in KIT, DENND3, PTPRU, MGA, and CYLD were identified. Mechanistically, depletion of the CYLD protein resulted in increased proliferation of prostatic basal cells in vitro. Collectively, these studies show that prostatic BCC displays distinct genomic alterations from AAC and highlight a potential role for loss of chromosome 16 in the pathogenesis of this rare tumor type., (Copyright © 2023 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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7. Identification of an E3 ligase that targets the catalytic subunit of RNA Polymerase I upon transcription stress.
- Author
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Pitts S, Liu H, Ibrahim A, Garg A, Felgueira CM, Begum A, Fan W, Teh S, Low JY, Ford B, Schneider DA, Hay R, and Laiho M
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- Catalytic Domain, RNA Polymerase I genetics, RNA Polymerase I metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Ubiquitination, Humans, F-Box Proteins genetics, F-Box Proteins metabolism, SKP Cullin F-Box Protein Ligases genetics, SKP Cullin F-Box Protein Ligases metabolism, Transcription, Genetic genetics
- Abstract
RNA Polymerase I (Pol I) synthesizes rRNA, which is the first and rate-limiting step in ribosome biogenesis. Factors governing the stability of the polymerase complex are not known. Previous studies characterizing Pol I inhibitor BMH-21 revealed a transcriptional stress-dependent pathway for degradation of the largest subunit of Pol I, RPA194. To identify the E3 ligase(s) involved, we conducted a cell-based RNAi screen for ubiquitin pathway genes. We establish Skp-Cullin-F-box protein complex F-box protein FBXL14 as an E3 ligase for RPA194. We show that FBXL14 binds to RPA194 and mediates RPA194 ubiquitination and degradation in cancer cells treated with BMH-21. Mutation analysis in yeast identified lysines 1150, 1153, and 1156 on Rpa190 relevant for the protein degradation. These results reveal the regulated turnover of Pol I, showing that the stability of the catalytic subunit is controlled by the F-box protein FBXL14 in response to transcription stress., Competing Interests: Conflict of interest M. L., H. L., A. B., and W. F. hold patents or patent applications on Pol I inhibitors, which are managed by the Johns Hopkins University. All other authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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8. Comprehensive assessment of anaplastic lymphoma kinase in localized and metastatic prostate cancer reveals targetable alterations.
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Patel RA, Coleman I, Roudier MP, Konnick EQ, Hanratty B, Dumpit R, Lucas JM, Ang LS, Low JY, Tretiakova MS, Ha G, Lee JK, True LD, De Marzo AM, Nelson PS, Morrissey C, Pritchard CC, and Haffner MC
- Subjects
- Male, Humans, Anaplastic Lymphoma Kinase genetics, Protein Kinase Inhibitors pharmacology, Protein-Tyrosine Kinases genetics, Lung Neoplasms drug therapy, Prostatic Neoplasms drug therapy
- Abstract
Anaplastic lymphoma kinase (ALK) is a tyrosine kinase with genomic and expression changes in many solid tumors. ALK inhibition is first line therapy for lung cancers with ALK alterations, and an effective therapy in other tumor types, but has not been well-studied in prostate cancer. Here, we aim to delineate the role of ALK genomic and expression changes in primary and metastatic prostate cancer. We determined ALK expression by immunohistochemistry and RNA-Seq, and genomic alterations by NGS. We assessed functional consequences of ALK overexpression and pharmacological ALK inhibition by cell proliferation and cell viability assays. Among 372 primary prostate cancer cases we identified one case with uniformly high ALK protein expression. Genomic analysis revealed a SLC45A3-ALK fusion which promoted oncogenesis in in vitro assays. We observed ALK protein expression in 5/52 (9%) of metastatic prostate cancer cases, of which 4 of 5 had neuroendocrine features. ALK-expressing neuroendocrine prostate cancer had a distinct transcriptional program, and earlier disease progression. An ALK-expressing neuroendocrine prostate cancer model was sensitive to pharmacological ALK inhibition. In summary, we found that ALK overexpression is rare in primary prostate cancer, but more frequent in metastatic prostate cancers with neuroendocrine differentiation. Further, ALK fusions similar to lung cancer are an occasional driver in prostate cancer. Our data suggest that ALK-directed therapies could be an option in selected patients with advanced prostate cancer., Competing Interests: Conflict of interest disclosure statement: No potential conflicts of interest were disclosed by the other authors.
- Published
- 2022
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9. Surgical Management of Missed Pediatric Monteggia Fractures: A Systematic Review and Meta-Analysis.
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Tan SHS, Low JY, Chen H, Tan JYH, Lim AKS, and Hui JH
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- Child, Humans, Range of Motion, Articular, Retrospective Studies, Ulna, Elbow Joint, Monteggia's Fracture diagnostic imaging, Monteggia's Fracture surgery
- Abstract
Objectives: To review surgical management and outcomes of missed pediatric Monteggia fractures., Data Sources: A systematic review was conducted using PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library from inception through March 2, 2020. The keywords were "Monteggia fracture," "missed Monteggia," "neglected Monteggia," "chronic Monteggia," and "chronic radial head dislocation.", Study Selection: All original human studies on missed pediatric Monteggia fractures were included. Congenital Monteggia fractures and isolated radial head dislocations were excluded., Data Extraction: The revised Methodological Index for Nonrandomised Studies tool was used to assess the quality of studies., Data Synthesis: Each patient's data were retrieved individually. The χ2 test and Fisher exact test were used to analyze the difference in outcomes for different surgical managements. Multivariate analysis was performed for variables that were significant on univariate analysis., Conclusions: Thirty studies with 600 patients were included. Proximal ulnar osteotomies (P = 0.016) and the absence of transcapitellar pinning (P = 0.001) were the most significant predictors for eventual reduction of radial head. Other surgical management variables were not significant predictors. These include open or closed reduction approach of radial head reduction; presence or absence of ulnar osteotomy; presence or absence of lengthening, angular correction, overcorrection, or bone grafting of ulnar osteotomy; type of fixation for ulnar osteotomy; presence or absence of radial osteotomy; presence or absence of annular ligament repair or reconstruction; and repair or reconstruction of annular ligament., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: The authors report no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2022
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10. Caveolae-Associated Molecules, Tumor Stroma, and Cancer Drug Resistance: Current Findings and Future Perspectives.
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Low JY and Laiho M
- Abstract
The discovery of small, "cave-like" invaginations at the plasma membrane, called caveola, has opened up a new and exciting research area in health and diseases revolving around this cellular ultrastructure. Caveolae are rich in cholesterol and orchestrate cellular signaling events. Within caveola, the caveola-associated proteins, caveolins and cavins, are critical components for the formation of these lipid rafts, their dynamics, and cellular pathophysiology. Their alterations underlie human diseases such as lipodystrophy, muscular dystrophy, cardiovascular disease, and diabetes. The expression of caveolins and cavins is modulated in tumors and in tumor stroma, and their alterations are connected with cancer progression and treatment resistance. To date, although substantial breakthroughs in cancer drug development have been made, drug resistance remains a problem leading to treatment failures and challenging translation and bench-to-bedside research. Here, we summarize the current progress in understanding cancer drug resistance in the context of caveola-associated molecules and tumor stroma and discuss how we can potentially design therapeutic avenues to target these molecules in order to overcome treatment resistance.
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- 2022
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11. Fructose intolerance is not associated with malabsorption in patients with functional gastrointestinal disorders.
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Wilder-Smith C, Lee SH, Olesen SS, Low JY, Kioh DYQ, Ferraris R, Materna A, and Chan ECY
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- Adult, Breath Tests, Cross-Over Studies, Double-Blind Method, Fatty Acids, Volatile blood, Female, Fructose administration & dosage, Fructose Intolerance blood, Fructose Intolerance diagnosis, Gastrointestinal Diseases blood, Humans, Malabsorption Syndromes blood, Male, Middle Aged, Young Adult, Fructose Intolerance complications, Gastrointestinal Diseases complications, Malabsorption Syndromes complications
- Abstract
Background: Symptoms following fructose ingestion, or fructose intolerance, are common in patients with functional gastrointestinal disorders (FGID) and are generally attributed to intestinal malabsorption. The relationships between absorption, symptoms, and intestinal gas production following fructose ingestion were studied in patients with FGID., Methods: Thirty FGID patients ingested a single dose of fructose 35 g or water in a randomized, double-blind, crossover study. Blood and breath gas samples were collected, and gastrointestinal symptoms rated. Plasma fructose metabolites and short-chain fatty acids were quantified by targeted liquid chromatography-tandem mass spectrometry. Patients were classified as fructose intolerant or tolerant based on symptoms following fructose ingestion., Key Results: The median (IQR) areas under the curve of fructose plasma concentrations within the first 2 h (AUC
0-2 h ) after fructose ingestion were similar for patients with and without fructose intolerance (578 (70) µM·h vs. 564 (240) µM·h, respectively, p = 0.39), as well as for the main fructose metabolites. There were no statistically significant correlations between the AUC0-2 h of fructose or its metabolites concentrations and the AUCs of symptoms, breath hydrogen, and breath methane. However, the AUCs of symptoms correlated significantly and positively with the AUC0-2 h of hydrogen and methane breath concentrations (r = 0.73, r = 0.62, respectively), and the AUCs of hydrogen and methane concentrations were greater in the fructose-intolerant than in the fructose-tolerant patients after fructose ingestion (p ≤ 0.02)., Conclusions & Inferences: Fructose intolerance in FGID is not related to post-ingestion plasma concentrations of fructose and its metabolites. Factors other than malabsorption, such as altered gut microbiota or sensory function, may be important mechanisms., (© 2021 John Wiley & Sons Ltd.)- Published
- 2021
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12. Association between pet ownership and physical activity and mental health during the COVID-19 "circuit breaker" in Singapore.
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Tan JSQ, Fung W, Tan BSW, Low JY, Syn NL, Goh YX, and Pang J
- Abstract
Introduction: The negative impact of the coronavirus disease 2019 (COVID-19) pandemic on mental health and physical activity is well reported. While prior studies showed a positive influence of pet ownership on physical activity and mental health, the interactions between the pandemic and pet ownership are not well studied., Objective: To determine the association between pet ownership, physical activity levels and mental health during the COVID-19 pandemic., Materials and Methods: A cross-sectional study was conducted from May 19 to July 13, 2020 among Singapore residents aged 21 to 64 years through a previously published questionnaire. Inverse probability treatment weighting was used to develop mixed-effects models for outcome comparisons. We recorded participant data on pet ownership, duration and intensity of physical activity, and RAND 36-item Health Survey mental health domains during the COVID-19 pandemic., Results: The questionnaire was completed by 431 pet owners and 103 non-pet owners. A greater proportion of pet owners were female, non-married, employed and owned pets in the past. Pet owners reported 31.8 (95% CI 13.6 to 50; p = .001) more minutes per week of mild-intensity physical activity compared to non-pet owners. No statistically significant differences were found for moderate- and vigorous-intensity physical activity. Pet owners had better emotional well-being ( ꞵ = 9.66, 95% CI 4.97 to 14.4; p < .001), energy ( ꞵ = 8.29, 95% CI 3.46 to 13.1; p = .001) and social functioning ( ꞵ = 11.2, 95% CI 5.03 to 17.4; p < .001) scores than non-pet owners. However, no statistically significant difference was observed for general health scores. Pet owner physical activity levels, general health, emotional well-being and energy scores correlated positively with pet attachment scores., Conclusion: Pet ownership was associated with greater physical activity levels and better mental health, particularly in main caregivers with higher pet attachment scores. These findings suggest that pet ownership is beneficial to physical and mental well-being during periods of social isolation amidst a global pandemic., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)
- Published
- 2021
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13. Phenotypic characterization of two novel cell line models of castration-resistant prostate cancer.
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Haffner MC, Bhamidipati A, Tsai HK, Esopi DM, Vaghasia AM, Low JY, Patel RA, Guner G, Pham MT, Castagna N, Hicks J, Wyhs N, Aebersold R, De Marzo AM, Nelson WG, Guo T, and Yegnasubramanian S
- Subjects
- Animals, Cell Line, Tumor, Cell Proliferation, Humans, Male, Phenotype, Prostatic Neoplasms, Castration-Resistant pathology
- Abstract
Background: Resistance to androgen deprivation therapies is a major driver of mortality in advanced prostate cancer. Therefore, there is a need to develop new preclinical models that allow the investigation of resistance mechanisms and the assessment of drugs for the treatment of castration-resistant prostate cancer., Methods: We generated two novel cell line models (LAPC4-CR and VCaP-CR) which were derived by passaging LAPC4 and VCaP cells in vivo and in vitro under castrate conditions. We performed detailed transcriptomic (RNA-seq) and proteomic analyses (SWATH-MS) to delineate expression differences between castration-sensitive and castration-resistant cell lines. Furthermore, we characterized the in vivo and in vitro growth characteristics of these novel cell line models., Results: The two cell line derivatives LAPC4-CR and VCaP-CR showed castration-resistant growth in vitro and in vivo which was only minimally inhibited by AR antagonists, enzalutamide, and bicalutamide. High-dose androgen treatment resulted in significant growth arrest of VCaP-CR but not in LAPC4-CR cells. Both cell lines maintained AR expression, but exhibited distinct expression changes on the mRNA and protein level. Integrated analyses including data from LNCaP and the previously described castration-resistant LNCaP-abl cells revealed an expression signature of castration resistance., Conclusions: The two novel cell line models LAPC4-CR and VCaP-CR and their comprehensive characterization on the RNA and protein level represent important resources to study the molecular mechanisms of castration resistance., (© 2021 Wiley Periodicals LLC.)
- Published
- 2021
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14. Maintaining oral hydration in older adults in surgical wards: a best practice implementation project.
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Seah KH, Low APS, Low JY, Luk GKS, Chia HX, and Goh ML
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- Aged, Drinking, Humans, Hospitals, Water-Electrolyte Balance
- Abstract
Introduction and Aim: Oral hydration is essential in older adults as poor hydration can complicate existing medical conditions and increase morbidity. Older adults in surgical wards are at risk of dehydration due to insufficient fluid consumption. The aim of this project is to ensure patients aged 65 years and above are adequately hydrated., Methods: The current project was conducted over 7 months from February to August 2019 and involved pre and postimplementation audits to ensure compliance with best practice. The Joanna Briggs Institute Practical Application of Clinical Evidence System and the Getting Research into Practice tools were used as a guide. Audits were conducted at four surgical wards with a sample of 42 patients at each audit. The measures implemented include educating nurses on the importance of oral hydration in older adult patients and labelling water jugs to encourage fluid intake among these patients., Results: Nurses' compliance in monitoring older adult patients' daily fluid intake increased from 5 to 76% at follow-up audit (P < 0.05). In addition, the average amount of fluid consumed over 3 days increased from 858.23 to 1037.50 ml., Conclusion: This project demonstrated a significant increase in oral fluid intake among older adult patients during hospitalization and their understanding of adequate fluid intake. Nurses play an important role in ensuring adequate amounts of daily fluid intake by these patients., (Copyright © 2021 JBI. Unauthorized reproduction of this article is prohibited.)
- Published
- 2021
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15. The hexosamine biosynthetic pathway and cancer: Current knowledge and future therapeutic strategies.
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Lam C, Low JY, Tran PT, and Wang H
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- Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Cell Proliferation, Drug Resistance, Neoplasm drug effects, Gene Expression Regulation, Neoplastic drug effects, Humans, Neoplasms drug therapy, Uridine Diphosphate N-Acetylglucosamine metabolism, Biosynthetic Pathways drug effects, Hexosamines biosynthesis, Neoplasms metabolism
- Abstract
The hexosamine biosynthetic pathway (HBP) is a glucose metabolism pathway that results in the synthesis of a nucleotide sugar UDP-GlcNAc, which is subsequently used for the post-translational modification (O-GlcNAcylation) of intracellular proteins that regulate nutrient sensing and stress response. The HBP is carried out by a series of enzymes, many of which have been extensively implicated in cancer pathophysiology. Increasing evidence suggests that elevated activation of the HBP may act as a cancer biomarker. Inhibition of HBP enzymes could suppress tumor cell growth, modulate the immune response, reduce resistance, and sensitize tumor cells to conventional cancer therapy. Therefore, targeting the HBP may serve as a novel strategy for treating cancer patients. Here, we review the current findings on the significance of HBP enzymes in various cancers and discuss future approaches for exploiting HBP inhibition for cancer treatment., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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16. Publisher Correction: Association between pet ownership and physical activity levels, atopic conditions, and mental health in Singapore: a propensity score-matched analysis.
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Goh YX, Tan JSQ, Syn NL, Tan BSW, Low JY, Foo YH, Fung W, Hoong BYD, and Pang J
- Published
- 2021
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17. The impact of death and dying on the personhood of medical students: a systematic scoping review.
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Ho CY, Kow CS, Chia CHJ, Low JY, Lai YHM, Lauw SK, How AEH, Tan LHE, Ngiam XLL, Chan NPX, Kuek TYJ, Kamal NHA, Chia JL, Abdurrahman ABHM, Chiam M, Ong YT, Chin AMC, Toh YP, Mason S, and Krishna LKR
- Subjects
- COVID-19 mortality, Curriculum, Humans, Pandemics, Research Design, SARS-CoV-2, Schools, Medical organization & administration, Social Support, Death, Personhood, Students, Medical psychology
- Abstract
Background: The re-introduction of medical students into healthcare systems struggling with the COVID-19 pandemic raises concerns as to whether they will be supported when confronted with death and dying patients in resource-limited settings and with reduced support from senior clinicians. Better understanding of how medical students respond to death and dying will inform educationalists and clinicians on how to best support them., Methods: We adopt Krishna's Systematic Evidence Based Approach to carry out a Systematic Scoping Review (SSR in SEBA) on the impact of death and dying on medical students. This structured search process and concurrent use of thematic and directed content analysis of data from six databases (Split Approach) enhances the transparency and reproducibility of this review., Results: Seven thousand six hundred nineteen were identified, 149 articles reviewed and 52 articles included. The Split Approach revealed similar themes and categories that correspond to the Innate, Individual, Relational and Societal domains in the Ring Theory of Personhood., Conclusion: Facing death and dying amongst their patients affect how medical students envisage their personhood. This underlines the need for timely, holistic and longitudinal support systems to ensure that problems faced are addressed early. To do so, there must be effective training and a structured support mechanism.
- Published
- 2020
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18. Association between pet ownership and physical activity levels, atopic conditions, and mental health in Singapore: a propensity score-matched analysis.
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Goh YX, Tan JSQ, Syn NL, Tan BSW, Low JY, Foo YH, Fung W, Hoong BYD, and Pang J
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- Adult, Animals, Cross-Sectional Studies, Eczema epidemiology, Female, Humans, Male, Middle Aged, Pets, Rhinitis, Allergic epidemiology, Singapore epidemiology, Young Adult, Eczema prevention & control, Exercise, Health Behavior, Human-Animal Bond, Mental Health, Ownership, Rhinitis, Allergic prevention & control
- Abstract
Although existing literature increasingly suggests a positive influence of pet ownership on human physical activity levels, results from many European, American, and Japanese studies have been inconsistent. How pet ownership impacts mental health and atopy is likewise controversial and whether distinct demographic subgroups experience differential effects is unclear. This cross-sectional study surveyed participants (n = 823) via a self-administered online questionnaire. Comparisons of outcomes between pet owners and non-pet owners with subgroup analyses were performed within a propensity score-matched subset (n = 566) of respondents. There were no differences in physical activity levels or mental health scores between pet owners and non-pet owners. In subgroup analyses, compared to non-pet owners, main pet caregivers reported 14.1 (95% CI 2.79-25.3) and 19.0 (95% CI 4.70-33.3) more minutes per week of moderate- and vigorous-intensity physical activity respectively and higher SF-36 emotional well-being (β = 2.7, 95% CI 0.100-5.32) and energy scores (β = 3.8, 95% CI 0.410-7.27). Age was a significant effect modifier of the association between pet ownership and emotional well-being, energy and social functioning scores, with greater scores above the ages of 39, 35 and 39 years old respectively (interaction p = 0.043, 0.044, 0.042). Finally, pet acquisition was associated with worsening of allergic rhinitis, while pet ownership cessation was associated with improvement of allergic rhinitis and eczema symptoms. To our knowledge, this is the first study addressing the public health impact of pet ownership in Southeast Asia and its findings add contextual nuance to suggest potential benefits derived from pet ownership.
- Published
- 2020
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19. Stromal CAVIN1 Controls Prostate Cancer Microenvironment and Metastasis by Modulating Lipid Distribution and Inflammatory Signaling.
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Low JY, Brennen WN, Meeker AK, Ikonen E, Simons BW, and Laiho M
- Subjects
- Humans, Male, Neoplasm Metastasis, Signal Transduction, Tumor Microenvironment, Inflammation genetics, Lipid Metabolism genetics, Prostatic Neoplasms genetics, RNA-Binding Proteins metabolism
- Abstract
Lipid uptake occurs through caveolae, plasma membrane invaginations formed by caveolins (CAV) and caveolae-associated protein 1 (CAVIN1). Genetic alterations of CAV1N1 and CAV1 modify lipid metabolism and underpin lipodystrophy syndromes. Lipids contribute to tumorigenesis by providing fuel to cancer metabolism and supporting growth and signaling. Tumor stroma promotes tumor proliferation, invasion, and metastasis, but how stromal lipids influence these processes remain to be defined. Here, we show that stromal CAVIN1 regulates lipid abundance in the prostate cancer microenvironment and suppresses metastasis. We show that depletion of CAVIN1 in prostate stromal cells markedly reduces their lipid droplet accumulation and increases inflammation. Stromal cells lacking CAVIN1 enhance prostate cancer cell migration and invasion. Remarkably, they increase lipid uptake and M2 inflammatory macrophage infiltration in the primary tumors and metastasis to distant sites. Our data support the concept that stromal cells contribute to prostate cancer aggressiveness by modulating lipid content and inflammation in the tumor microenvironment. IMPLICATIONS: This study showed that stromal CAVIN1 suppresses prostate cancer metastasis by modulating tumor microenvironment, lipid content, and inflammatory response., (©2020 American Association for Cancer Research.)
- Published
- 2020
- Full Text
- View/download PDF
20. Using Telemedicine for Outpatient Geriatric Care During the Novel Coronavirus Outbreak: Experience from the First 15 Patients.
- Author
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Tan LL, Pillay VD, Chia JW, Seah AS, Liu CM, Lim Y, and Low JY
- Subjects
- Aged, Aged, 80 and over, Attitude of Health Personnel, COVID-19, Female, Humans, Male, Patient Satisfaction, Pilot Projects, Proof of Concept Study, Singapore, Ambulatory Care, Geriatrics, Telemedicine, Videoconferencing
- Published
- 2020
21. Effective targeting of RNA polymerase I in treatment-resistant prostate cancer.
- Author
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Low JY, Sirajuddin P, Moubarek M, Agarwal S, Rege A, Guner G, Liu H, Yang Z, De Marzo AM, Bieberich C, and Laiho M
- Subjects
- Animals, Benzamides, Cell Growth Processes drug effects, Cell Line, Tumor, Drug Resistance, Neoplasm, Enzyme Inhibitors pharmacology, Humans, Male, Mice, Mice, Nude, Molecular Targeted Therapy, Nitriles, PC-3 Cells, Phenylthiohydantoin analogs & derivatives, Phenylthiohydantoin pharmacology, Prostatic Neoplasms enzymology, Prostatic Neoplasms genetics, Prostatic Neoplasms pathology, Prostatic Neoplasms, Castration-Resistant enzymology, Prostatic Neoplasms, Castration-Resistant genetics, Prostatic Neoplasms, Castration-Resistant pathology, RNA Polymerase I genetics, RNA Polymerase I metabolism, RNA, Ribosomal genetics, Random Allocation, Transcription, Genetic drug effects, Xenograft Model Antitumor Assays, Heterocyclic Compounds, 4 or More Rings pharmacology, Prostatic Neoplasms drug therapy, Prostatic Neoplasms, Castration-Resistant drug therapy, RNA Polymerase I antagonists & inhibitors
- Abstract
Background: Advanced prostate cancers depend on protein synthesis for continued survival and accelerated rates of metabolism for growth. RNA polymerase I (Pol I) is the enzyme responsible for ribosomal RNA (rRNA) transcription and a rate-limiting step for ribosome biogenesis. We have shown using a specific and sensitive RNA probe for the 45S rRNA precursor that rRNA synthesis is increased in prostate adenocarcinoma compared to nonmalignant epithelium. We have introduced a first-in-class Pol I inhibitor, BMH-21, that targets cancer cells of multiple origins, and holds potential for clinical translation., Methods: The effect of BMH-21 was tested in prostate cancer cell lines and in prostate cancer xenograft and mouse genetic models., Results: We show that BMH-21 inhibits Pol I transcription in metastatic, castration-resistant, and enzalutamide treatment-resistant prostate cancer cell lines. The genetic abrogation of Pol I effectively blocks the growth of prostate cancer cells. Silencing of p53, a pathway activated downstream of Pol I, does not diminish this effect. We find that BMH-21 significantly inhibited tumor growth and reduced the Ki67 proliferation index in an enzalutamide-resistant xenograft tumor model. A decrease in 45S rRNA synthesis demonstrated on-target activity. Furthermore, the Pol I inhibitor significantly inhibited tumor growth and pathology in an aggressive genetically modified Hoxb13-MYC|Hoxb13-Cre|Pten
fl/fl (BMPC) mouse prostate cancer model., Conclusion: Taken together, BMH-21 is a novel promising molecule for the treatment of castration-resistant prostate cancer., (© 2019 Wiley Periodicals, Inc.)- Published
- 2019
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- View/download PDF
22. A surprise aberrant pulmonary vein.
- Author
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Low JY, Nardini M, Zirafa C, and Melfi F
- Subjects
- Brachiocephalic Veins diagnostic imaging, Brachiocephalic Veins surgery, Diagnosis, Differential, Humans, Intraoperative Period, Pulmonary Veins diagnostic imaging, Pulmonary Veins surgery, Vascular Malformations surgery, Brachiocephalic Veins abnormalities, Pneumonectomy methods, Pulmonary Veins abnormalities, Vascular Malformations diagnosis, Vascular Surgical Procedures methods
- Abstract
We report an incidental discovery of the superior pulmonary vein coming from a strange anatomical location when performing a robotic left lower lobectomy. When trying to identify the superior pulmonary vein, an aberrant pulmonary vein was found leading into the innominate vein., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
23. Carbohydrate Taste Sensitivity Is Associated with Starch Intake and Waist Circumference in Adults.
- Author
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Low JY, Lacy KE, McBride RL, and Keast RS
- Subjects
- Adult, Female, Humans, Male, Young Adult, Oligosaccharides chemistry, Polysaccharides chemistry, Taste physiology, Waist Circumference
- Abstract
Background: Recent studies have proposed that humans may perceive complex carbohydrates and that sensitivity to simple carbohydrates is independent of sensitivity to complex carbohydrates. Variation in oral complex carbohydrate sensitivity may influence food consumption. Objective: This study aimed to investigate the associations between oral complex carbohydrate sensitivity, anthropometry, and dietary intake in adults. Methods: We assessed oral sensitivity to complex carbohydrates (maltodextrin and oligofructose) by measuring detection thresholds (DTs) and suprathreshold intensity perceptions (STs) for 34 participants, including 16 men (mean ± SEM age : 26.2 ± 0.4 y; range: 24-30 y) and 18 women (age: 29.4 ± 2.1 y; range: 24-55 y). We also measured height, weight, and waist circumference (WC) and participants completed a 4-d food diary and a food-frequency questionnaire. Results: Measurements of oral sensitivity to complex carbohydrates were significantly correlated with WC and dietary energy and starch intakes (DT: r = -0.38, P < 0.05; ST: r = 0.36-0.48, P < 0.05). When participants were grouped into tertiles, there were significant differences in WC and total energy or starch intakes for those who were more sensitive or experienced high intensity compared with those who were less sensitive or experienced low intensity. Being more sensitive or experiencing high intensity was associated with greater energy (7968-8954 kJ/d) and starch (29.1-29.8% of energy) intakes and a greater WC (88.2-91.4 cm) than was being less sensitive or experiencing low intensity (6693-7747 kJ/d, 20.9-22.2% of energy, and 75.5-80.5 cm, respectively). Conclusion: Complex carbohydrate sensing is associated with WC and consumption of complex carbohydrates and energy in adults. This trial was registered at anzctr.org.au as ACTRN12616001356459., Competing Interests: Author disclosures: JYQL, KEL, RLM, and RSJK, no conflicts of interest., (© 2017 American Society for Nutrition.)
- Published
- 2017
- Full Text
- View/download PDF
24. Psychophysical Evaluation of Sweetness Functions Across Multiple Sweeteners.
- Author
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Low JY, McBride RL, Lacy KE, and Keast RS
- Subjects
- Adolescent, Adult, Humans, Male, Middle Aged, Psychophysics, Young Adult, Sweetening Agents analysis, Taste
- Abstract
Sweetness is one of the 5 prototypical tastes and is activated by sugars and non-nutritive sweeteners (NNS). The aim of this study was to investigate measures of sweet taste function [detection threshold (DT), recognition threshold (RT), and suprathreshold intensity ratings] across multiple sweeteners. Sixty participants, 18-52 years of age (mean age in years = 26, SD = ±7.8), were recruited to participate in the study. DT and RT were collected for caloric sweeteners (glucose, fructose, sucrose, erythritol) and NNS (sucralose, rebaudioside A). Sweetness intensity for all sweeteners was measured using a general Labeled Magnitude Scale. There were strong correlations between DT and RT of all 4 caloric sweeteners across people (r = 0.62-0.90, P < 0.001), and moderate correlations between DT and RT for both of the NNS (r = 0.39-0.48, P < 0.05); however, weaker correlations were observed between the DT or RT of the caloric sweeteners and NNS (r = 0.26-0.48, P < 0.05). The DT and RT of glucose and fructose were not correlated with DT or RT of sucralose (P > 0.05). In contrast, there were strong correlations between the sweetness intensity ratings of all sweeteners (r = 0.70-0.96, P < 0.001). This suggests those caloric sweeteners and NNS access at least partially independent mechanisms with respect to DT and RT measures. At suprathreshold level, however, the strong correlation between caloric sweeteners and NNS through weak, moderate, and strong intensity indicates a commonality in sweet taste mechanism for the perceived intensity range., (© The Author 2016. Published by Oxford University Press.)
- Published
- 2017
- Full Text
- View/download PDF
25. Featural information is sufficient to produce a left cheek bias for happiness perception.
- Author
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Low JY and Lindell AK
- Subjects
- Adult, Female, Functional Laterality physiology, Humans, Male, Middle Aged, Young Adult, Cheek physiology, Facial Expression, Facial Recognition physiology, Happiness, Social Perception
- Abstract
People perceive the left cheek as more emotionally expressive than the right. Both configural and featural information enable the evaluation of emotional expressions; whether they make equivalent contributions to the left cheek bias is undetermined. As scrambling faces disrupts configural processing whilst leaving featural information intact, we investigated whether configural information is necessary, or featural information is sufficient, to induce a left cheek bias for emotion perception. Eighty-one participants (65 F, 16 M) viewed two types of left and right cheek image pairs - normal, scrambled - and indicated which image appeared happier (half mirror-reversed to control for perceptual biases). Results indicated a left cheek bias for both normal and scrambled faces, irrespective of mirror reversal. As scrambling faces disrupts configural processing, the fact that the left cheek was perceived as more expressive even when scrambled confirms that differences between the cheeks' featural information are sufficient to induce the left cheek bias., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
26. The Association between Sweet Taste Function, Anthropometry, and Dietary Intake in Adults.
- Author
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Low JY, Lacy KE, McBride R, and Keast RS
- Subjects
- Adult, Carbohydrates, Diet, Female, Humans, Male, Anthropometry, Feeding Behavior, Sweetening Agents, Taste Perception
- Abstract
Variation in ability to detect, recognize, and perceive sweetness may influence food consumption, and eventually chronic nutrition-related conditions such as overweight and obesity. The aim of this study was to investigate the associations between sweet taste function, anthropometry, and dietary intake in adults. Participants' (n = 60; mean age in years = 26, SD = ±7.8) sweet taste function for a range of sweeteners (glucose, fructose, sucrose, sucralose, erythritol, and Rebaudioside A) was assessed by measuring detection and recognition thresholds and sweetness intensity. Height, weight, and waist circumference were also measured, and participants also completed a Food Frequency Questionnaire. There was large inter-individual variation in detection, recognition and sweetness intensity measures. Pearson's correlation coefficient revealed no robust correlations between measures of sweet taste function, anthropometry, and dietary intake, with the exception of suprathreshold intensity, which was moderately correlated with total energy intake (r = 0.23-0.40). One-way analysis of variance revealed no significant differences between the most and least sensitive participants in terms of BMI, waist circumference, and dietary intake for all measures of sweet taste function and sweeteners (all p > 0.01). When stratified into BMI categories, there were no significant differences in any measure of sweet taste function between the normal weight and overweight/obese participants (all p > 0.01). Results show that that sweet taste function is not associated with anthropometry and sweetness intensity measures are the most appropriate measure when assessing links between sweet taste and food consumption.
- Published
- 2016
- Full Text
- View/download PDF
27. Epigenetic modifications of caveolae associated proteins in health and disease.
- Author
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Low JY and Nicholson HD
- Subjects
- Animals, Caveolin 1 genetics, Caveolin 1 metabolism, Caveolin 2 genetics, Caveolin 2 metabolism, DNA Methylation, Gene Expression Regulation, Humans, Membrane Proteins metabolism, MicroRNAs genetics, Neoplasms genetics, Neoplasms metabolism, RNA Interference, RNA-Binding Proteins genetics, RNA-Binding Proteins metabolism, Caveolae metabolism, Epigenesis, Genetic, Genetic Predisposition to Disease, Membrane Proteins genetics
- Abstract
Caveolae are small, "omega-shaped" invaginations at the plasma membrane of the cell which are involved in a variety of processes including cholesterol transport, potocytosis and cell signalling. Within caveolae there are caveolae-associated proteins, and changes in expression of these molecules have been described to play a role in the pathophysiology of various diseases including cancer and cardiovascular disease. Evidence is beginning to accumulate that epigenetic processes may regulate the expression of these caveolae related genes, and hence contribute to disease progression. Here, we summarize the current knowledge of the role of epigenetic modification in regulating the expression of these caveolae related genes and how this relates to changes in cellular physiology and in health and disease.
- Published
- 2015
- Full Text
- View/download PDF
28. Emerging role of polymerase-1 and transcript release factor (PTRF/ Cavin-1) in health and disease.
- Author
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Low JY and Nicholson HD
- Subjects
- Animals, Cellular Senescence, Humans, Lipid Metabolism, Models, Biological, RNA-Binding Proteins chemistry, Disease, Health, RNA-Binding Proteins metabolism
- Abstract
Polymerase-1 and release transcript factor (PTRF) was initially reported to be involved in the termination of the transcription process. More recently, it has been implicated in the formation of caveolae, cave-like structures in the plasma membrane. The effects of PTRF related to caveolae suggest that this protein may play important roles in health and disease. PTRF is highly expressed in various cells, including adipocytes, osteoblasts and muscle (cardiac, skeletal and smooth) cells. The role of PTRF in prostate cancer has been recently reviewed but there is growing evidence that PTRF is involved in other physiological processes such as cell repair and the regulation of glucose and lipid metabolism and, furthermore, altered expression of PTRF may be associated with disease. This review discusses the emerging role of PTRF in health and disease.
- Published
- 2014
- Full Text
- View/download PDF
29. See the Seal? Understanding Restrained Eaters' Responses to Nutritional Messages on Food Packaging.
- Author
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Lwin MO, Morrin M, Tang SW, Low JY, Nguyen T, and Lee WX
- Abstract
Food packaging in general and packaging incorporating health messages in particular have been active areas of inquiry, receiving attention from policymakers and food manufacturers alike. This study explores the effects of package seals and claims on perceived product healthfulness as a function of dietary restraint status. A laboratory experiment using realistic three-dimensional packaging shows that for restrained eaters (i.e., those who try to restrict their food intake), nutrition claims on "healthy" products and nutrition seals on "unhealthy" products are effective at enhancing perceptions of product healthfulness. Unrestrained eaters, in contrast, are largely unaffected by nutrition seals and claims. These results provide insights into restrained eaters' purchase motivations, as well as guidance for policymakers seeking to regulate the use of seals and claims.
- Published
- 2014
- Full Text
- View/download PDF
30. Hormones, polyamines, and cell wall metabolism during oil palm fruit mesocarp development and ripening.
- Author
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Teh HF, Neoh BK, Wong YC, Kwong QB, Ooi TE, Ng TL, Tiong SH, Low JY, Danial AD, Ersad MA, Kulaveerasingam H, and Appleton DR
- Subjects
- Abscisic Acid metabolism, Actins genetics, Actins metabolism, Arecaceae growth & development, Cell Wall enzymology, Crops, Agricultural enzymology, Crops, Agricultural growth & development, Crosses, Genetic, Fruit growth & development, Gibberellins genetics, Gibberellins metabolism, Indoleacetic Acids metabolism, Lipid Metabolism, Malaysia, Plant Proteins genetics, Plant Proteins metabolism, Pollination, Polygalacturonase genetics, Polygalacturonase metabolism, RNA, Messenger metabolism, RNA, Plant metabolism, Up-Regulation, Arecaceae metabolism, Cell Wall metabolism, Crops, Agricultural metabolism, Fruit metabolism, Gene Expression Regulation, Plant, Plant Growth Regulators biosynthesis, Polyamines metabolism
- Abstract
Oil palm is one of the most productive oil-producing crops and can store up to 90% oil in its fruit mesocarp. Oil palm fruit is a sessile drupe consisting of a fleshy mesocarp from which palm oil is extracted. Biochemical changes in the mesocarp cell walls, polyamines, and hormones at different ripening stages of oil palm fruits were studied, and the relationship between the structural and the biochemical metabolism of oil palm fruits during ripening is discussed. Time-course analysis of the changes in expression of polyamines, hormones, and cell-wall-related genes and metabolites provided insights into the complex processes and interactions involved in fruit development. Overall, a strong reduction in auxin-responsive gene expression was observed from 18 to 22 weeks after pollination. High polyamine concentrations coincided with fruit enlargement during lipid accumulation and latter stages of maturation. The trend of abscisic acid (ABA) concentration was concordant with GA₄ but opposite to the GA₃ profile such that as ABA levels increase the resulting elevated ABA/GA₃ ratio clearly coincides with maturation. Polygalacturonase, expansin, and actin gene expressions were also observed to increase during fruit maturation. The identification of the master regulators of these coordinated processes may allow screening for oil palm variants with altered ripening profiles.
- Published
- 2014
- Full Text
- View/download PDF
31. Differential metabolite profiles during fruit development in high-yielding oil palm mesocarp.
- Author
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Teh HF, Neoh BK, Hong MP, Low JY, Ng TL, Ithnin N, Thang YM, Mohamed M, Chew FT, Yusof HM, Kulaveerasingam H, and Appleton DR
- Subjects
- Amino Acids metabolism, Arecaceae genetics, Biomarkers metabolism, Breeding methods, Chromatography, Liquid, Citric Acid metabolism, Fruit growth & development, Gas Chromatography-Mass Spectrometry, Malates metabolism, Metabolomics methods, Principal Component Analysis, Arecaceae metabolism, Fruit metabolism, Gene Expression Regulation, Developmental physiology, Gene Expression Regulation, Plant physiology, Lipids biosynthesis
- Abstract
To better understand lipid biosynthesis in oil palm mesocarp, in particular the differences in gene regulation leading to and including de novo fatty acid biosynthesis, a multi-platform metabolomics technology was used to profile mesocarp metabolites during six critical stages of fruit development in comparatively high- and low-yielding oil palm populations. Significantly higher amino acid levels preceding lipid biosynthesis and nucleosides during lipid biosynthesis were observed in a higher yielding commercial palm population. Levels of metabolites involved in glycolysis revealed interesting divergence of flux towards glycerol-3-phosphate, while carbon utilization differences in the TCA cycle were proven by an increase in malic acid/citric acid ratio. Apart from insights into the regulation of enhanced lipid production in oil palm, these results provide potentially useful metabolite yield markers and genes of interest for use in breeding programmes.
- Published
- 2013
- Full Text
- View/download PDF
32. Optimization of extraction time and temperature on antioxidant activity of Schizophyllum commune aqueous extract using response surface methodology.
- Author
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Yim HS, Chye FY, Rao V, Low JY, Matanjun P, How SE, and Ho CW
- Abstract
Central composite design of response surface methodology (RSM) was employed to optimize the extraction time (X 1 : 99.5-290.5 min) and temperature (X 2 : 30.1-54.9 °C) of Schizophyllum commune aqueous extract with high antioxidant activities and total phenolic content (TPC). Results indicated that the data were adequately fitted into four second-order polynomial models. The extraction time and temperature were found to have significant linear, quadratic and interaction effects on antioxidant activities and TPC. The optimal extraction time and temperature were: 290.5 min and 35.7 °C (DPPH(•) scavenging ability); 180.7 min and 41.7 °C (ABTS(•+) inhibition ability); 185.2 min and 42.4 °C (ferric reducing antioxidant power, FRAP); 290.5 min and 40.3 °C (TPC). These optimum conditions yielded 85.10%; 94.31%; 0.74 mM Fe(2+) equivalent/100 g; 635.76 mg gallic acid equivalent/100 g, respectively. The yields of antioxidant activities and TPC obtained experimentally were close to its predicted values. The establishment of such model provides a good experimental basis employing RSM for optimizing the extraction time and temperature on antioxidants from S. commune aqueous extract.
- Published
- 2013
- Full Text
- View/download PDF
33. miR-145-dependent targeting of junctional adhesion molecule A and modulation of fascin expression are associated with reduced breast cancer cell motility and invasiveness.
- Author
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Götte M, Mohr C, Koo CY, Stock C, Vaske AK, Viola M, Ibrahim SA, Peddibhotla S, Teng YH, Low JY, Ebnet K, Kiesel L, and Yip GW
- Subjects
- Actins analysis, Breast Neoplasms metabolism, Cell Line, Tumor, Cytoskeleton, Down-Regulation, Female, Humans, Microfilament Proteins analysis, Muscle Proteins analysis, Neoplasm Invasiveness, Plasminogen Activator Inhibitor 1 analysis, Receptors, Cell Surface, Sialoglycoproteins analysis, Breast Neoplasms pathology, Carrier Proteins metabolism, Cell Adhesion Molecules metabolism, Cell Movement, Immunoglobulins metabolism, MicroRNAs metabolism, Microfilament Proteins metabolism
- Abstract
Micro RNAs are small non-coding RNAs, which regulate fundamental cellular and developmental processes at the transcriptional and translational level. In breast cancer, miR-145 expression is downregulated compared with healthy control tissue. As several predicted targets of miR-145 potentially regulate cell motility, we aimed at investigating a potential role for miR-145 in breast cancer cell motility and invasiveness. Assisted by Affymetrix array technology, we demonstrate that overexpression of miR-145 in MDA-MB-231, MCF-7, MDA-MB-468 and SK-BR-3 breast cancer cells and in Ishikawa endometrial carcinoma cells leads to a downregulation of the cell-cell adhesion protein JAM-A and of the actin bundling protein fascin. Moreover, podocalyxin and Serpin E1 mRNA levels were downregulated, and gamma-actin, transgelin and MYL9 were upregulated upon miR-145 overexpression. These miR-145-dependent expression changes drastically decreased cancer cell motility, as revealed by time-lapse video microscopy, scratch wound closure assays and matrigel invasion assays. Immunofluorescence microscopy demonstrated restructuring of the actin cytoskeleton and a change in cell morphology by miR-145 overexpression, resulting in a more cortical actin distribution, and reduced actin stress fiber and filopodia formation. Nuclear rotation was observed in 10% of the pre-miR-145 transfected MDA-MB-231 cells, accompanied by a reduction of perinuclear actin. Luciferase activation assays confirmed direct miR-145-dependent regulation of the 3'UTR of JAM-A, whereas siRNA-mediated knockdown of JAM-A expression resulted in decreased motility and invasiveness of MDA-MB-231 and MCF-7 breast cancer cells. Our data identify JAM-A and fascin as novel targets of miR-145, firmly establishing a role for miR-145 in modulating breast cancer cell motility. Our data provide a rationale for future miR-145-targeted approaches of antimetastatic cancer therapy.
- Published
- 2010
- Full Text
- View/download PDF
34. Sjögren-larsson syndrome and crystalline maculopathy associated with a novel mutation.
- Author
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Jean-François E, Low JY, Gonzales CR, and Sarraf D
- Subjects
- Adult, Crystallization, DNA Mutational Analysis, Fluorescein Angiography, Humans, Male, Polymerase Chain Reaction, Tomography, Optical Coherence, Aldehyde Oxidoreductases genetics, Mutation, Retinal Diseases genetics, Sjogren-Larsson Syndrome genetics
- Published
- 2007
- Full Text
- View/download PDF
35. Randomized controlled trial of trimebutine (anal sphincter relaxant) for pain after haemorrhoidectomy.
- Author
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Ho YH, Seow-Choen F, Low JY, Tan M, and Leong AP
- Subjects
- Female, Humans, Male, Manometry, Pain Measurement, Parasympatholytics administration & dosage, Pilot Projects, Suppositories, Trimebutine administration & dosage, Hemorrhoids surgery, Pain, Postoperative prevention & control, Parasympatholytics therapeutic use, Trimebutine therapeutic use
- Abstract
Background: Anal sphincter spasm may aggravate pain after haemorrhoidectomy. The aims of this study were to investigate whether a trimebutine suppository (Proctolog) reduced anal resting pressure and, subsequently, to test its efficacy in relieving pain after haemorrhoidectomy., Methods: Ten patients underwent anal manometry before and 4 h after Proctolog application. A controlled randomized trial was then conducted on 160 consecutive patients. A standard haemorrhoidectomy was performed. Eighty patients were then randomized to receive an application of Proctolog immediately after the procedure (group 1). The remaining 80 did not receive a suppository (controls, group 2). An independent, blinded observer determined the pain scores., Results: Proctolog resulted in a mean 35 per cent reduction in resting anal pressure (P < 0.001). However, there were no differences in the pain score at 4 h after haemorrhoidectomy, maximum pain during the first 24 h, maximum pain during the second postoperative day, ketoprofen requirement or need for intramuscular pethidine injections between groups 1 and 2., Conclusion: Although Proctolog reduced mean resting anal pressure at 4 h after application, this did not affect pain after haemorrhoidectomy.
- Published
- 1997
36. Biofeedback therapy for excessive stool frequency and incontinence following anterior resection or total colectomy.
- Author
-
Ho YH, Chiang JM, Tan M, and Low JY
- Subjects
- Fecal Incontinence etiology, Fecal Incontinence physiopathology, Fecal Incontinence psychology, Female, Humans, Male, Manometry, Middle Aged, Prospective Studies, Treatment Outcome, Biofeedback, Psychology, Colectomy, Defecation physiology, Fecal Incontinence therapy, Postoperative Complications therapy
- Abstract
Purpose: Excessive stool frequency and incontinence after anterior resection (AR) or total colectomy (TC) can be refractory to expectancy and antidiarrheal agents. We prospectively assessed efficacy of anorectal biofeedback therapy (BF) in this clinical situation., Methods: Thirteen patients (10 men and 3 women; mean age, 62.1 (standard error of the mean (SEM), 4.6) years) had more than six bowel movements per day and/or episodes of incontinence, which did not abate after antidiarrheal agents were given for at least six (mean, 27.9 (SEM, 6.3)) months after surgery. All underwent four sessions of outpatient BF. Assessment was by continence questionnaire and anorectal physiology tests, which were administered before and after BF., Results: In seven AR patients, daily stool frequency was decreased (8.7 (SEM, 2.1) before and 4.6 (SEM, 1.2) after, P < 0.05), and daily incontinence episodes were reduced (2.7 (SEM, 0.9) before and 0.4 (SEM, 0.2) after, P < 0.05) after BF. Six TC patients also had decreased daily stool frequency (6.2 (SEM, 2.1) before, 3.3 (SEM, 1.6) after; P < 0.05) and incontinence episodes (2.4 (SEM, 0.9) before, 0.5 (SEM, 1) after; P < 0.05) after BF. There were no significant changes in anorectal physiology parameters after BF. At a mean follow-up of 10.6 (SEM, 2.5) months after BF, there were no regressions or complications., Conclusions: BF is a safe and effective option for refractory excessive stool frequency and/or incontinence following AR or TC.
- Published
- 1996
- Full Text
- View/download PDF
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