29 results on '"Leong HY"'
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2. Bridging artificial intelligence and fucoxanthin for the recovery and quantification from microalgae.
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Chong JWR, Tang DYY, Leong HY, Khoo KS, Show PL, and Chew KW
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- Humans, Fuzzy Logic, Neural Networks, Computer, Artificial Intelligence, Microalgae
- Abstract
Fucoxanthin is a carotenoid that possesses various beneficial medicinal properties for human well-being. However, the current extraction technologies and quantification techniques are still lacking in terms of cost validation, high energy consumption, long extraction time, and low yield production. To date, artificial intelligence (AI) models can assist and improvise the bottleneck of fucoxanthin extraction and quantification process by establishing new technologies and processes which involve big data, digitalization, and automation for efficiency fucoxanthin production. This review highlights the application of AI models such as artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS), capable of learning patterns and relationships from large datasets, capturing non-linearity, and predicting optimal conditions that significantly impact the fucoxanthin extraction yield. On top of that, combining metaheuristic algorithm such as genetic algorithm (GA) can further improve the parameter space and discovery of optimal conditions of ANN and ANFIS models, which results in high R
2 accuracy ranging from 98.28% to 99.60% after optimization. Besides, AI models such as support vector machine (SVM), convolutional neural networks (CNNs), and ANN have been leveraged for the quantification of fucoxanthin, either computer vision based on color space of images or regression analysis based on statistical data. The findings are reliable when modeling for the concentration of pigments with high R2 accuracy ranging from 66.0% - 99.2%. This review paper has reviewed the feasibility and potential of AI for the extraction and quantification purposes, which can reduce the cost, accelerate the fucoxanthin yields, and development of fucoxanthin-based products.- Published
- 2023
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3. Need analysis of a dietary application among caregivers of patients with disorders of amino acid metabolism (AAMDs): A mixed-method approach.
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Lim JY, Ali NM, Rajikan R, Amit N, Hamid HA, Leong HY, Mohamad M, Koh BQ, and Musa A
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- Child, Humans, Diet, Smartphone, Amino Acids, Caregivers, Mobile Applications
- Abstract
Background: A dietary application can assist the caregivers of AAMDs children in auto-calculating the protein intake, hence improving dietary compliance. However, existing dietary application for patients with AAMDs only focus on delivering the nutritional content of food and monitoring the dietary intake but were lacking in other educational components., Objective: To assess the uses, needs and preferences towards a dietary application among the caregivers of AAMDs patients., Methods: We conducted a mixed-method study comprising focus group discussion (FGD) and a quantitative questionnaire survey among caregivers of patients aged between 6-month-old to 18-year-old with AAMDs who are receiving active treatment, both medical and dietetic treatment in the genetic clinic, Hospital Kuala Lumpur (HKL)., Results: A total of 76 and 20 caregivers participated in the survey and FGD respectively. All the caregivers (100%) possessed a smartphone and most of the caregivers (89.5%) had the experience of using smartphone or other technological devices to search for health or medical information. However, majority of the participants were not aware of the existence of any web-based or mobile application related to AAMDs (89.5%). While for the qualitative part, three themes emerged: (1) experience with current source of information; (2) needs for supporting self-management educational contents and needs for technological design application. Most of the caregivers used the nutritional booklet as sources of reference but some of them searched for web-based information. Features perceived by the caregivers included a digital food composition database, sharing diet recall with healthcare providers, self-monitoring diet intake as well as low protein recipes. Besides that, user-friendly and ease to use were also perceived as the important features by the caregivers., Conclusion: The identified features and needs by the caregivers should be integrated into the design of the apps to promote acceptance and usage., 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 B.V. All rights reserved.)
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- 2023
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4. Genotype, phenotype and treatment outcomes of 17 Malaysian patients with infantile-onset Pompe disease and the identification of 3 novel GAA variants.
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Chan MY, Jalil JA, Yakob Y, Wahab SAA, Ali EZ, Khalid MKNM, Leong HY, Chew HB, Sivabalakrishnan JB, and Ngu LH
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- Humans, alpha-Glucosidases genetics, Genotype, Glycogen, Muscle Hypotonia, Phenotype, Retrospective Studies, Treatment Outcome, Cardiomyopathy, Hypertrophic drug therapy, Cardiomyopathy, Hypertrophic genetics, Glycogen Storage Disease Type II drug therapy, Glycogen Storage Disease Type II genetics, Glycogen Storage Disease Type II diagnosis
- Abstract
Background: Pompe disease is a rare glycogen storage disorder caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA), leading to glycogen deposition in multiple tissues. Infantile-onset Pompe disease (IOPD) patients present within the first year of life with profound hypotonia and hypertrophic cardiomyopathy. Treatment with enzyme replacement therapy (ERT) has significantly improved survival for this otherwise lethal disorder. This study aims to describe the clinical and molecular spectrum of Malaysian IOPD patients, and to analyze their long term treatment outcomes., Methods: Seventeen patients diagnosed with IOPD between 2000 and 2020 were included in this retrospective cohort study. Clinical and biochemical data were collated and analyzed using descriptive statistics. GAA enzyme levels were performed on dried blood spots. Molecular analysis of the GAA gene was performed by polymerase chain reaction and Sanger sequencing. Structural modelling was used to predict the effect of the novel mutations on enzyme structure., Results: Our cohort had a median age of presentation of 3 months and median age of diagnosis of 6 months. Presenting features were hypertrophic cardiomyopathy (100%), respiratory insufficiency (94%), hypotonia (88%), failure to thrive (82%), feeding difficulties (76%), and hepatomegaly (76%). Fourteen different mutations in the GAA gene were identified, with three novel mutations, c.1552-14_1552-1del, exons 2-3 deletion and exons 6-10 deletion. The most common mutation identified was c.1935C > A p.(D645E), with an allele frequency of 33%. Sixteen patients received ERT at the median age of 7 months. Overall survival was 29%. Mean age of death was 17.5 months. Our longest surviving patient has atypical IOPD and is currently 20 years old., Conclusions: This is the first study to analyze the genotype and phenotype of Malaysian IOPD patients, and has identified the c.1935C > A p.(D645E) as the most common mutation. The three novel mutations reported in this study expands the mutation spectrum for IOPD. Our low survival rate underscores the importance of early diagnosis and treatment in achieving better treatment outcomes., (© 2023. Institut National de la Santé et de la Recherche Médicale (INSERM).)
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- 2023
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5. Brain monoamine vesicular transport disease caused by homozygous SLC18A2 variants: A study in 42 affected individuals.
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Saida K, Maroofian R, Sengoku T, Mitani T, Pagnamenta AT, Marafi D, Zaki MS, O'Brien TJ, Karimiani EG, Kaiyrzhanov R, Takizawa M, Ohori S, Leong HY, Akay G, Galehdari H, Zamani M, Romy R, Carroll CJ, Toosi MB, Ashrafzadeh F, Imannezhad S, Malek H, Ahangari N, Tomoum H, Gowda VK, Srinivasan VM, Murphy D, Dominik N, Elbendary HM, Rafat K, Yilmaz S, Kanmaz S, Serin M, Krishnakumar D, Gardham A, Maw A, Rao TS, Alsubhi S, Srour M, Buhas D, Jewett T, Goldberg RE, Shamseldin H, Frengen E, Misceo D, Strømme P, Magliocco Ceroni JR, Kim CA, Yesil G, Sengenc E, Guler S, Hull M, Parnes M, Aktas D, Anlar B, Bayram Y, Pehlivan D, Posey JE, Alavi S, Madani Manshadi SA, Alzaidan H, Al-Owain M, Alabdi L, Abdulwahab F, Sekiguchi F, Hamanaka K, Fujita A, Uchiyama Y, Mizuguchi T, Miyatake S, Miyake N, Elshafie RM, Salayev K, Guliyeva U, Alkuraya FS, Gleeson JG, Monaghan KG, Langley KG, Yang H, Motavaf M, Safari S, Alipour M, Ogata K, Brown AEX, Lupski JR, Houlden H, and Matsumoto N
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- Humans, Animals, Rats, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Vesicular Monoamine Transport Proteins genetics, Vesicular Monoamine Transport Proteins metabolism, Amines, Brain metabolism, Brain Diseases, Movement Disorders genetics, Dystonia
- Abstract
Purpose: Brain monoamine vesicular transport disease is an infantile-onset movement disorder that mimics cerebral palsy. In 2013, the homozygous SLC18A2 variant, p.Pro387Leu, was first reported as a cause of this rare disorder, and dopamine agonists were efficient for treating affected individuals from a single large family. To date, only 6 variants have been reported. In this study, we evaluated genotype-phenotype correlations in individuals with biallelic SLC18A2 variants., Methods: A total of 42 affected individuals with homozygous SLC18A2 variant alleles were identified. We evaluated genotype-phenotype correlations and the missense variants in the affected individuals based on the structural modeling of rat VMAT2 encoded by Slc18a2, with cytoplasm- and lumen-facing conformations. A Caenorhabditis elegans model was created for functional studies., Results: A total of 19 homozygous SLC18A2 variants, including 3 recurrent variants, were identified using exome sequencing. The affected individuals typically showed global developmental delay, hypotonia, dystonia, oculogyric crisis, and autonomic nervous system involvement (temperature dysregulation/sweating, hypersalivation, and gastrointestinal dysmotility). Among the 58 affected individuals described to date, 16 (28%) died before the age of 13 years. Of the 17 patients with p.Pro237His, 9 died, whereas all 14 patients with p.Pro387Leu survived. Although a dopamine agonist mildly improved the disease symptoms in 18 of 21 patients (86%), some affected individuals with p.Ile43Phe and p.Pro387Leu showed milder phenotypes and presented prolonged survival even without treatment. The C. elegans model showed behavioral abnormalities., Conclusion: These data expand the phenotypic and genotypic spectra of SLC18A2-related disorders., (Copyright © 2022 American College of Medical Genetics and Genomics. Published by Elsevier Inc. All rights reserved.)
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- 2023
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6. Molecular, Biochemical, and Clinical Characterization of Thirteen Patients with Glycogen Storage Disease 1a in Malaysia.
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Abdul Wahab SA, Yakob Y, Mohd Khalid MKN, Ali N, Leong HY, and Ngu LH
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- Glucose, Glucose-6-Phosphatase genetics, Glucose-6-Phosphatase metabolism, Glucose-6-Phosphate, Glycogen Storage Disease Type I, Hepatomegaly, Humans, Malaysia epidemiology, Mutation, Phosphates, Retrospective Studies, Glycogen Storage Disease genetics, Hypoglycemia
- Abstract
Background: Glycogen storage disease type 1a (GSD1a) is a rare autosomal recessive metabolic disorder characterized by hypoglycaemia, growth retardation, lactic acidosis, hepatomegaly, hyperlipidemia, and nephromegaly. GSD1a is caused by a mutation in the G6PC gene encoding glucose-6-phosphatase (G6Pase); an enzyme that catalyses the hydrolysis of glucose-6-phosphate (G6P) to phosphate and glucose., Objective: To elaborate on the clinical findings, biochemical data, molecular genetic analysis, and short-term prognosis of 13 GSD1a patients in Malaysia., Methods: The information about 13 clinically classified GSD1a patients was retrospectively studied. The G6PC mutation analysis was performed by PCR-DNA sequencing., Results: Patients were presented with hepatomegaly (92%), hypoglycaemia (38%), poor weight gain (23%), and short stature (15%). Mutation analysis revealed nine heterozygous mutations; eight previously reported mutations (c.155 A > T, c.209 G > A, c.226 A > T, c.248 G > A, c.648 G > T, c.706 T > A, c.1022 T > A, c.262delG) and a novel mutation (c.325 T > C). The most common mutation found in Malaysian patients was c.648 G > T in ten patients (77%) of mostly Malay ethnicity, followed by c.248 G > A in 4 patients of Chinese ethnicity (30%). A novel missense mutation (c.325 T > C) was predicted to be disease-causing by various in silico software., Conclusions: The establishment of G6PC molecular genetic testing will enable the detection of presymptomatic patients, assisting in genetic counselling while avoiding the invasive methods of liver biopsy., Competing Interests: All authors declare that there are no conflicts of interest., (Copyright © 2022 Siti Aishah Abdul Wahab et al.)
- Published
- 2022
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7. Exploring the Barriers and Motivators to Dietary Adherence among Caregivers of Children with Disorders of Amino Acid Metabolism (AAMDs): A Qualitative Study.
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Lim JY, Rajikan R, Amit N, Ali NM, Hamid HA, Leong HY, Mohamad M, Koh BQ, and Musa A
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- Amino Acids, Child, Diet, Humans, Qualitative Research, Caregivers, Quality of Life
- Abstract
Dietary intervention is generally accepted as the mainstay of treatment for patients with disorders of amino acid metabolism (AAMDs). However, dietary adherence to a low-protein diet is always reported as a common challenge among these patients. This study explored the perception of barriers and motivators to dietary adherence among caregivers of AAMD patients in Malaysia. Twenty caregivers of children with AAMDs receiving ongoing treatment at the genetic clinic participated in an online focus group discussion from November to December 2021. Findings showed a total of five interrelated main themes identified from focus group discussion (FGD) exploring parents' experiences related to the management of their child's daily diet. The barriers to dietary adherence were burden of dietary treatment, diet and dietary behavior, parenting challenges, limited knowledge related to dietary treatment, and challenges in healthcare system delivery. Key factors facilitating good dietary adherence include good knowledge of dietary treatment, parental coping strategies, social coping, and dietary behavior. In conclusion, despite the existence of several barriers to the implementation of dietary treatment, caregivers managed to use a wide range of coping strategies to overcome some, if not all, of the challenges. The important next step is to develop, in conjunction with multidisciplinary healthcare professionals, feasible implementation strategies that could address these barriers and at the same time improve the quality of life of caregivers.
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- 2022
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8. Downstream processing of virus-like particles with aqueous two-phase systems: Applications and challenges.
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Leong HY, Fu XQ, Show PL, Yao SJ, and Lin DQ
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- Animals, Vaccines, Virus-Like Particle
- Abstract
The advancement of recombinant virus-like particle-based vaccines has attracted global attention owing to substantially safety and high efficacy in provoking a protective immunity against various chronic and infectious diseases in humans and animals. A robust, low-cost, and scalability separation and purification technology is of utmost importance in the downstream processing of recombinant virus-like particles to produce affordable and safe vaccines. Being a relatively simple, environmentally friendly, and efficient biomolecules recovery approach, aqueous two-phase systems have received great attention from researchers worldwide. This review aims to highlight the challenges and outlook in addition to the current applications of aqueous two-phase systems in downstream processing of virus-like particles. The efforts will confidently reinforce scholars' knowledge and fill in the valuable research gap in the aspect of concerning recombinant virus-like particle-based vaccines development, particularly related to the virus-like particles downstream production processes., (© 2022 Wiley-VCH GmbH.)
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- 2022
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9. Phytochemistry, Bioactivities and Traditional Uses of Michelia × alba .
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Cheng KK, Nadri MH, Othman NZ, Rashid SNAA, Lim YC, and Leong HY
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- Anti-Inflammatory Agents analysis, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents therapeutic use, Antioxidants chemistry, Humans, Phytochemicals analysis, Phytochemicals pharmacology, Plant Extracts chemistry, Plant Leaves chemistry, Magnoliaceae, Oils, Volatile chemistry
- Abstract
Michelia × alba ( M. alba ) is a flowering tree best known for its essential oil, which has long been used as a fragrance ingredient for perfume and cosmetics. In addition, the plant has been used in traditional medicine in Asia and dates back hundreds of years. To date, there is a limited number of publications on the bioactivities of M. alba , which focused on its tyrosinase inhibition, antimicrobial, antidiabetic, anti-inflammatory, and antioxidant activities. Nevertheless, M. alba may have additional unexplored bioactivities associated with its bioactive compounds such as linalool (72.8% in flower oil and 80.1% in leaf oil), α-terpineol (6.04% flower oil), phenylethyl alcohol (2.58% flower oil), β-pinene (2.39% flower oil), and geraniol (1.23% flower oil). Notably, these compounds have previously been reported to exhibit therapeutic activities such as anti-cancer, anti-inflammation, anti-depression, anti-ulcer, anti-hypertriglyceridemia, and anti-hypertensive activities. In this review paper, we examine and discuss the scientific evidence on the phytochemistry, bioactivities, and traditional uses of M. alba . Here, we report a total of 168 M. alba biological compounds and highlight the therapeutic potential of its key bioactive compounds. This review may provide insights into the therapeutic potential of M. alba and its biologically active components for the prevention and treatment of diseases and management of human health and wellness.
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- 2022
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10. How does the Internet of Things (IoT) help in microalgae biorefinery?
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Wang K, Khoo KS, Leong HY, Nagarajan D, Chew KW, Ting HY, Selvarajoo A, Chang JS, and Show PL
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- Biofuels, Biomass, Plants, Internet of Things, Microalgae
- Abstract
Microalgae biorefinery is a platform for the conversion of microalgal biomass into a variety of value-added products, such as biofuels, bio-based chemicals, biomaterials, and bioactive substances. Commercialization and industrialization of microalgae biorefinery heavily rely on the capability and efficiency of large-scale cultivation of microalgae. Thus, there is an urgent need for novel technologies that can be used to monitor, automatically control, and precisely predict microalgae production. In light of this, innovative applications of the Internet of things (IoT) technologies in microalgae biorefinery have attracted tremendous research efforts. IoT has potential applications in a microalgae biorefinery for the automatic control of microalgae cultivation, monitoring and manipulation of microalgal cultivation parameters, optimization of microalgae productivity, identification of toxic algae species, screening of target microalgae species, classification of microalgae species, and viability detection of microalgal cells. In this critical review, cutting-edge IoT technologies that could be adopted to microalgae biorefinery in the upstream and downstream processing are described comprehensively. The current advances of the integration of IoT with microalgae biorefinery are presented. What this review discussed includes automation, sensors, lab-on-chip, and machine learning, which are the main constituent elements and advanced technologies of IoT. Specifically, future research directions are discussed with special emphasis on the development of sensors, the application of microfluidic technology, robotized microalgae, high-throughput platforms, deep learning, and other innovative techniques. This review could contribute greatly to the novelty and relevance in the field of IoT-based microalgae biorefinery to develop smarter, safer, cleaner, greener, and economically efficient techniques for exhaustive energy recovery during the biorefinery process., (Copyright © 2021 Elsevier Inc. All rights reserved.)
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- 2022
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11. Development of proton-exchange membrane fuel cell with ionic liquid technology.
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Khoo KS, Chia WY, Wang K, Chang CK, Leong HY, Maaris MNB, and Show PL
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- Electrolytes, Membranes, Artificial, Protons, Technology, Ionic Liquids
- Abstract
Fuel cells (FCs) are a chemical fuel device which can directly convert chemical energy into electrical energy, also known as electrochemical generator. Proton exchange membrane fuel cells (PEMFCs) are one of the most appealing FC systems that have been broadly developed in recent years. Due to the poor conductivity of electrolyte membrane used in traditional PEMFC, its operation at higher temperature is greatly limited. The incorporation of ionic liquids (ILs) which is widely regarded as a greener alternative compared to traditional solvents in the proton exchange membrane electrolyte shows great potential in high temperature PEMFCs (HT-PEMFCs). This review provides insights in the latest progress of utilizing ILs as an electrochemical electrolyte in PEMFCs. Besides, electrolyte membranes that are constructed by ILs combined with polybenzimidazole (PBI) have many benefits such as better thermal stability, improved mechanical properties, and higher proton conductivity. The current review aims to investigate the newest development and existing issues of ILs research in electrolyte and material selection, system fabrication method, synthesis of ILs, and experimental techniques. The evaluation of life cycle analysis, commercialization, and greenness of ILs are also discussed. Hence, this review provides insights to material scientists and develops interest of wider community, promoting the use of ILs to meet energy challenges., 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 © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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12. Effect of nutritional intervention on nutritional status among children with disorders of amino acid and nitrogen metabolism (AANMDs): A scoping review.
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Lim JY, Amit N, Ali NM, Leong HY, Mohamad M, and Rajikan R
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Disorders of amino acid and nitrogen metabolism (AANMDs) occur due to an enzyme deficiency in a normal biochemical pathway. Nutritional intervention is recognized as the mainstay of treatment for children diagnosed with AANMD. Hence, this scoping review aimed to identify the nutritional interventions available in managing AANMD disorders and their effects on nutritional status. A systematic search using PRISMA Extension for Scoping Reviews (PRISMA-ScR) method was conducted across 4 databases: PubMed, ScienceDirect (Elsevier), EBSCOhost and Cochrane Central Register of Controlled Trials (CENTRAL). Inclusion criteria for the study to be selected are: subjects aged less than 18-year-old, article published in English, utilized an experimental design and published within the past 20 years. A total of 22 articles were included in this review. The majority of the subjects are boys (55.6%) and employed a randomized controlled trial (RCT) study design (45.4%). Nutritional interventions were categorized into 4 categories which are: "protein substitute" ( n = 5), "protein substitute with modified composition" ( n = 6), "nutrient supplementation (n=8)", and "distribution and dosage of protein substitute ( n = 3)". The most frequently assessed outcomes were biochemical parameters that gauge the effectiveness of metabolic control (68.2%). Overall, "protein substitute enriched with inhibitive amino acids", "long-chain polyunsaturated fatty acids supplementation", and "evenly distributed protein substitute" demonstrated beneficial effects towards the nutritional status, especially in terms of biochemical parameters. In summary, nutritional intervention plays a significant role in improving the nutritional status of AANMD patients. Further investigations of nutritional intervention among AANMD children using a meta-analysis approach are necessary for better comprehension of their impact in management of AANMD disorders., Competing Interests: The authors have no conflicts of interest to disclose., (2021, International Research and Cooperation Association for Bio & Socio - Sciences Advancement.)
- Published
- 2021
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13. Plastic waste associated with the COVID-19 pandemic: Crisis or opportunity?
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Khoo KS, Ho LY, Lim HR, Leong HY, and Chew KW
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- Animals, Humans, Pandemics, Plastics, SARS-CoV-2, COVID-19, Waste Management
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Coronavirus Diseases 2019 (COVID-19) pandemic has a huge impact on the plastic waste management in many countries due to the sudden surge of medical waste which has led to a global waste management crisis. Improper management of plastic waste may lead to various negative impacts on the environment, animals, and human health. However, adopting proper waste management and the right technologies, looking in a different perception of the current crisis would be an opportunity. About 40% of the plastic waste ended up in landfill, 25% incinerated, 16% recycled and the remaining 19% are leaked into the environment. The increase of plastic wastes and demand of plastic markets serve as a good economic indicator for investor and government initiative to invest in technologies that converts plastic waste into value-added product such as fuel and construction materials. This will close the loop of the life cycle of plastic waste by achieving a sustainable circular economy. This review paper will provide insight of the state of plastic waste before and during the COVID-19 pandemic. The treatment pathway of plastic waste such as sterilisation technology, incineration, and alternative technologies available in converting plastic waste into value-added product were reviewed., (Copyright © 2021 Elsevier B.V. All rights reserved.)
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- 2021
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14. A novel twin-column continuous chromatography approach for separation and enrichment of monoclonal antibody charge variants.
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Jing SY, Shi C, Leong HY, Yuan JJ, Gao D, Wang HB, Yao SJ, and Lin DQ
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Downstream processing of mAb charge variants is difficult owing to their similar molecular structures and surface charge properties. This study aimed to apply a novel twin-column continuous chromatography (called N-rich mode) to separate and enrich acidic variants of an IgG1 mAb. Besides, a comparison study with traditional scaled-up batch-mode cation exchange (CEX) chromatography was conducted. For the N-rich process, two 3.93 mL columns were used, and the buffer system, flow rate and elution gradient slope were optimized. The results showed that 1.33 mg acidic variants with nearly 100% purity could be attained after a 22-cycle accumulation. The yield was 86.21% with the productivity of 7.82 mg/L/h. On the other hand, for the batch CEX process, 4.15 mL column was first used to optimize the separation conditions, and then a scaled-up column of 88.20 mL was used to separate 1.19 mg acidic variants with the purity of nearly 100%. The yield was 59.18% with the productivity of 7.78 mg/L/h. By comparing between the N-rich and scaled-up CEX processes, the results indicated that the N-rich method displays a remarkable advantage on the product yield, i.e. 1.46-fold increment without the loss of productivity and purity. Generally, twin-column N-rich continuous chromatography displays a high potential to enrich minor compounds with a higher yield, more flexibility and lower resin cost., Competing Interests: The authors have declared no conflict of interest., (© 2021 The Authors. Engineering in Life Sciences published by Wiley‐VCH GmbH.)
- Published
- 2021
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15. Waste biorefinery towards a sustainable circular bioeconomy: a solution to global issues.
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Leong HY, Chang CK, Khoo KS, Chew KW, Chia SR, Lim JW, Chang JS, and Show PL
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Global issues such as environmental problems and food security are currently of concern to all of us. Circular bioeconomy is a promising approach towards resolving these global issues. The production of bioenergy and biomaterials can sustain the energy-environment nexus as well as substitute the devoid of petroleum as the production feedstock, thereby contributing to a cleaner and low carbon environment. In addition, assimilation of waste into bioprocesses for the production of useful products and metabolites lead towards a sustainable circular bioeconomy. This review aims to highlight the waste biorefinery as a sustainable bio-based circular economy, and, therefore, promoting a greener environment. Several case studies on the bioprocesses utilising waste for biopolymers and bio-lipids production as well as bioprocesses incorporated with wastewater treatment are well discussed. The strategy of waste biorefinery integrated with circular bioeconomy in the perspectives of unravelling the global issues can help to tackle carbon management and greenhouse gas emissions. A waste biorefinery-circular bioeconomy strategy represents a low carbon economy by reducing greenhouse gases footprint, and holds great prospects for a sustainable and greener world.
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- 2021
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16. Overproduction of lipoxygenase from Pseudomonas aeruginosa in Escherichia coli by auto-induction expression and its application in triphenylmethane dyes degradation.
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Lu J, Zhang C, Leong HY, Show PL, Lu F, and Lu Z
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- Escherichia coli genetics, Gene Expression Regulation, Bacterial, Lipoxygenase genetics, Pseudomonas aeruginosa genetics, Coloring Agents metabolism, Escherichia coli metabolism, Lipoxygenase metabolism, Pseudomonas aeruginosa enzymology
- Abstract
In this study, the bacterial lipoxygenase (LOX) gene from Pseudomonas aeruginosa ATCC27853 (pse-LOX) was cloned, sequenced and heterologous expressed in Escherichia coli by auto-induction expression strategy. Production of the recombinant pse-LOX (pse-rLOX) gene up to 23,850 U/mL (264 mg pure protein/L bacterial culture fluid) was observed in the end of this process. To the best of our knowledge, this is the first attempt to manipulate LOX heterologous expression process using auto-induction expression approach, and it is the highest production of recombinant LOX compared with other reports. Subsequently, the resulted pse-rLOX was proved to efficiently degrade triphenylmethane dyes such as malachite green, brilliant green and aniline blue. Generally, an overproduction of the LOX from P. aeruginosa was observed in E. coli, and this recombinant gene is a potential candidate as biocatalyst for triphenylmethane dyes decolorization., (Copyright © 2019 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
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17. Clinical, biochemical and genetic profiles of patients with mucopolysaccharidosis type IVA (Morquio A syndrome) in Malaysia: the first national natural history cohort study.
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Leong HY, Abdul Azize NA, Chew HB, Keng WT, Thong MK, Mohd Khalid MKN, Hung LC, Mohamed Zainudin N, Ramlee A, Md Haniffa MA, Yakob Y, and Ngu LH
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- Adolescent, Adult, Child, Child, Preschool, Chondroitinsulfatases genetics, Chondroitinsulfatases metabolism, Cohort Studies, Female, Humans, Malaysia, Male, Mucopolysaccharidosis IV metabolism, Young Adult, Mucopolysaccharidosis IV genetics, Mucopolysaccharidosis IV pathology
- Abstract
Background: Mucopolysaccharidosis IVA (MPS IVA) is an autosomal recessive lysosomal storage disease due to N-acetylgalactosamine-6-sulfatase (GALNS) deficiency. It results in accumulation of the glycosaminoglycans, keratan sulfate and chondroitin-6-sulfate, leading to skeletal and other systemic impairments. Data on MPS IVA in Asian populations are scarce., Methods: This is a multicentre descriptive case series of 21 patients comprising all MPS IVA patients in Malaysia. Mutational analysis was performed by PCR and Sanger sequencing of the GALNS gene in 17 patients., Results: The patients (15 females and 6 males) had a mean age (± SD) of 15.5 (± 8.1) years. Mean age at symptom onset was 2.6 (± 2.1) years and at confirmed diagnosis was 6.9 (± 4.5) years. The study cohort included patients from all the main ethnic groups in Malaysia - 57% Malay, 29% Chinese and 14% Indian. Common presenting symptoms included pectus carinatum (57%) and genu valgum (43%). Eight patients (38%) had undergone surgery, most commonly knee surgeries (29%) and cervical spine decompression (24%). Patients had limited endurance with lower mean walking distances with increasing age. GALNS gene analysis identified 18 distinct mutations comprising 13 missense, three nonsense, one small deletion and one splice site mutation. Of these, eight were novel mutations (Tyr133Ser, Glu158Valfs*12, Gly168*, Gly168Val, Trp184*, Leu271Pro, Glu320Lys, Leu508Pro). Mutations in exons 1, 5 and 9 accounted for 51% of the mutant alleles identified., Conclusions: All the MPS IVA patients in this study had clinical impairments. A better understanding of the natural history and the clinical and genetic spectrum of MPS IVA in this population may assist early diagnosis, improve management and permit timely genetic counselling and prenatal diagnosis.
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- 2019
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18. Liquid Biphasic Electric Partitioning System as a Novel Integration Process for Betacyanins Extraction From Red-Purple Pitaya and Antioxidant Properties Assessment.
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Leong HY, Chang YK, Ooi CW, Law CL, Julkifle AL, and Show PL
- Abstract
Nowadays, downstream bioprocessing industries inclines towards the development of a green and high efficient bioseparation technology. Betacyanins are presently gaining higher interest in the food science as driven by their high tinctorial strength and health promoting functional properties. In this study, a novel green integration process of liquid biphasic electric partitioning system (LBEPS) was proposed for betacyanins extraction from peel and flesh of red-purple pitaya. Initially, the betacyanins extraction using LBEPS with initial settings was compared with that of liquid biphasic partitioning system (LBPS), and the results revealed that both systems demonstrated a comparable betacyanins extraction. This was followed by further optimizing the LBEPS for better betacyanins extraction. Several operating parameters including operation time, voltage applied, and position of graphitic electrodes in the system were investigated. Moreover, comparison between optimized LBEPS and LBPS with optimized conditions of electric system (as post-treatment) as well as color characterization and antioxidant properties assessment were conducted. Overall, the betacyanins extraction employing the optimized LBEPS showed the significant highest values of betacyanins concentration in alcohol-rich top phase (C
t ) and partition coefficient (K) of betacyanins from peel (99.256 ± 0.014% and 133.433 ± 2.566) and flesh (97.189 ± 0.172% and 34.665 ± 2.253) of red-purple pitaya. These results inferred that an optimal betacyanins extraction was successfully achieved by this approach. Also, the LBEPS with the peel and flesh showed phase volume ratio (Vr ) values of 1.667 and 2.167, respectively, and this indicated that they have a clear biphasic separation. In addition, the peel and flesh extract obtained from the optimized LBEPS demonstrated different variations of red color as well as their antioxidant properties were well-retained. This article introduces a new, reliable, and effective bioseparation approach for the extraction of biomolecules, which is definitely worth to explore further as a bioseparation tool in the downstream bioprocessing.- Published
- 2019
- Full Text
- View/download PDF
19. Lafora disease in a Malaysian with a rare mutation in the EPM2A gene.
- Author
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Tee SK, Ong TL, Aris A, See SML, Leong HY, Khalid MKNM, and Shanthi V
- Subjects
- Adult, Humans, Malaysia, Male, Mutation, Missense, Lafora Disease diagnosis, Lafora Disease genetics, Protein Tyrosine Phosphatases, Non-Receptor genetics
- Published
- 2019
- Full Text
- View/download PDF
20. A review on the advanced leachate treatment technologies and their performance comparison: an opportunity to keep the environment safe.
- Author
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Show PL, Pal P, Leong HY, Juan JC, and Ling TC
- Subjects
- Bioreactors, Carbon Dioxide, Denitrification, Methane, Nitrification, Nitrogen, Oxidation-Reduction, Solid Waste, Environmental Monitoring, Waste Disposal Facilities, Waste Disposal, Fluid methods, Water Pollutants, Chemical analysis
- Abstract
Landfill application is the most common approach for biowaste treatment via leachate treatment system. When municipal solid waste deposited in the landfills, microbial decomposition breaks down the wastes generating the end products, such as carbon dioxide, methane, volatile organic compounds, and liquid leachate. However, due to the landfill age, the fluctuation in the characteristics of landfill leachate is foreseen in the leachate treatment plant. The focuses of the researchers are keeping leachate from contaminating groundwater besides keeping potent methane emissions from reaching the atmosphere. To address the above issues, scientists are required to adopt green biological methods to keep the environment safe. This review focuses on the assorting of research papers on organic content and nitrogen removal from the leachate via recent effective biological technologies instead of conventional nitrification and denitrification process. The published researches on the characteristics of various Malaysian landfill sites were also discussed. The understanding of the mechanism behind the nitrification and denitrification process will help to select an optimized and effective biological treatment option in treating the leachate waste. Recently, widely studied technologies for the biological treatment process are aerobic methane oxidation coupled to denitrification (AME-D) and partial nitritation-anammox (PN/A) process, and both were discussed in this review article. This paper gives the idea of the modification of the conventional treatment technologies, such as combining the present processes to make the treatment process more effective. With the integration of biological process in the leachate treatment, the effluent discharge could be treated in shortcut and novel pathways, and it can lead to achieving "3Rs" of reduce, reuse, and recycle approach.
- Published
- 2019
- Full Text
- View/download PDF
21. Production of bio-hydrogen from dairy wastewater using pretreated landfill leachate sludge as an inoculum.
- Author
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Wong YM, Show PL, Wu TY, Leong HY, Ibrahim S, and Juan JC
- Subjects
- Animals, Batch Cell Culture Techniques methods, Biocatalysis, Biological Oxygen Demand Analysis, Bioreactors microbiology, Cattle, Entropy, Fatty Acids, Volatile biosynthesis, Fermentation, Hydrogen-Ion Concentration, Temperature, Water Pollutants, Chemical chemistry, Water Purification methods, Dairying, Hydrogen metabolism, Sewage microbiology, Wastewater chemistry, Wastewater microbiology, Water Pollutants, Chemical metabolism
- Abstract
Bio-hydrogen production from wastewater using sludge as inoculum is a sustainable approach for energy production. This study investigated the influence of initial pH and temperature on bio-hydrogen production from dairy wastewater using pretreated landfill leachate sludge (LLS) as an inoculum. The maximum yield of 113.2 ± 2.9 mmol H
2 /g chemical oxygen demand (COD) (12.8 ± 0.3 mmol H2 /g carbohydrates) was obtained at initial pH 6 and 37 °C. The main products of volatile fatty acids were acetate and butyrate with the ratio of acetate:butyrate was 0.4. At optimum condition, Gibb's free energy was estimated at -40 kJ/mol, whereas the activation enthalpy and entropy were 65 kJ/mol and 0.128 kJ/mol/l, respectively. These thermodynamic quantities suggest that bio-hydrogen production from dairy wastewater using pretreated LLS as inoculum was effective and efficient. In addition, genomic and bioinformatics analyses were performed in this study., (Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
22. Development of Aurantiochytrium limacinum SR21 cultivation using salt-rich waste feedstock for docosahexaenoic acid production and application of natural colourant in food product.
- Author
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Leong HY, Su CA, Lee BS, Lan JC, Law CL, Chang JS, and Show PL
- Subjects
- Color, Stramenopiles drug effects, Docosahexaenoic Acids biosynthesis, Food, Sodium Chloride pharmacology, Stramenopiles metabolism
- Abstract
Microalgae biorefinery is presently receiving a lot of attention as driven by its production of high value-added products. In this study, an oleaginous microalga Aurantiochytrium limacinum SR21 was cultured for docosahexaenoic acid (DHA) production using 20% (w/v) of K
2 HPO4 -waste feedstock to replace 0.005% (w/v) of KH2 PO4 in the flask culture. DHA is an essential nutrient for human's brain functionalities. Collectively, the K2 HPO4 -waste feedstock with working concentration of 0.005% (w/v) in the cultivation prompted a higher lipid content (8.29%) and DHA production (128.81 mg.L-1 ). Moreover, natural plant pigment products containing stabilised betacyanins were utilised as natural red colourants for hard candy production. This study develops microalgal cultivation using salt-rich waste feedstock for a higher lipid and DHA content as well as application of natural colouring agents in food products., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
23. Fructose-1,6-bisphosphatase deficiency as a cause of recurrent hypoglycemia and metabolic acidosis: Clinical and molecular findings in Malaysian patients.
- Author
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Moey LH, Abdul Azize NA, Yakob Y, Leong HY, Keng WT, Chen BC, and Ngu LH
- Subjects
- Adult, Child, Child, Preschool, Female, Humans, Male, RNA-Binding Proteins, Recurrence, Retrospective Studies, Acidosis etiology, DNA Helicases genetics, DNA-Binding Proteins genetics, Fructose-1,6-Diphosphatase Deficiency complications, Hypoglycemia etiology, Mutation
- Abstract
Background: Fructose-1,6-bisphosphatase (FBPase) deficiency is a rare autosomal recessive inborn error of gluconeogenesis. We reported the clinical findings and molecular genetic data in seven Malaysian patients with FBPase deficiency., Methods: All patients diagnosed with FBPase deficiency from 2010 to 2015 were included in this study. Their clinical and laboratory data were collected retrospectively., Results: All the patients presented with recurrent episodes of hypoglycemia, metabolic acidosis, hyperlactacidemia and hepatomegaly. All of them had the first metabolic decompensation prior to 2 years old. The common triggering factors were vomiting and infection. Biallelic mutations in FBP1 gene (MIM*611570) were identified in all seven patients confirming the diagnosis of FBPase deficiency. In four patients, genetic study was prompted by detection of glycerol or glycerol-3-phosphate in urine organic acids analysis. One patient also had pseudo-hypertriglyceridemia. Seven different mutations were identified in FBP1, among them four mutations were new: three point deletions (c.392delT, c.603delG and c.704delC) and one splice site mutation (c.568-2A > C). All four new mutations were predicted to be damaging by in silico analysis. One patient presented in the neonatal period and succumbed due to sepsis and multi-organ failure. Among six survivors (current age ranged from 4 to 27 years), four have normal growth and cognitive development. One patient had short stature and another had neurological deficit following status epilepticus due to profound hypoglycemia., Conclusion: FBPase deficiency needs to be considered in any children with recurrent hypoglycemia and metabolic acidosis. Our study expands the spectrum of FBP1 gene mutations., (Copyright © 2017. Published by Elsevier B.V.)
- Published
- 2018
- Full Text
- View/download PDF
24. De novo hotspot variants in CYFIP2 cause early-onset epileptic encephalopathy.
- Author
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Nakashima M, Kato M, Aoto K, Shiina M, Belal H, Mukaida S, Kumada S, Sato A, Zerem A, Lerman-Sagie T, Lev D, Leong HY, Tsurusaki Y, Mizuguchi T, Miyatake S, Miyake N, Ogata K, Saitsu H, and Matsumoto N
- Subjects
- Adaptor Proteins, Signal Transducing chemistry, Adaptor Proteins, Signal Transducing metabolism, Animals, Brain diagnostic imaging, Cell Line, Transformed, Child, Child, Preschool, Electroencephalography, Female, Gene Expression Regulation, Developmental genetics, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, HEK293 Cells, Humans, Infant, Magnetic Resonance Imaging, Male, Mice, Models, Molecular, Pedigree, Spasms, Infantile diagnostic imaging, Transfection, Exome Sequencing, Adaptor Proteins, Signal Transducing genetics, Arginine genetics, Mutation genetics, Spasms, Infantile genetics
- Abstract
Objective: The cytoplasmic fragile X mental retardation 1 interacting proteins 2 (CYFIP2) is a component of the WASP-family verprolin-homologous protein (WAVE) regulatory complex, which is involved in actin dynamics. An obvious association of CYFIP2 variants with human neurological disorders has never been reported. Here, we identified de novo hotspot CYFIP2 variants in neurodevelopmental disorders and explore the possible involvement of the CYFIP2 mutants in the WAVE signaling pathway., Methods: We performed trio-based whole-exome sequencing (WES) in 210 families and case-only WES in 489 individuals with epileptic encephalopathies. The functional effect of CYFIP2 variants on WAVE signaling was evaluated by computational structural analysis and in vitro transfection experiments., Results: We identified three de novo CYFIP2 variants at the Arg87 residue in 4 unrelated individuals with early-onset epileptic encephalopathy. Structural analysis indicated that the Arg87 residue is buried at an interface between CYFIP2 and WAVE1, and the Arg87 variant may disrupt hydrogen bonding, leading to structural instability and aberrant activation of the WAVE regulatory complex. All mutant CYFIP2 showed comparatively weaker interactions to the VCA domain than wild-type CYFIP2. Immunofluorescence revealed that ectopic speckled accumulation of actin and CYFIP2 was significantly increased in cells transfected with mutant CYFIP2., Interpretation: Our findings suggest that de novo Arg87 variants in CYFIP2 have gain-of-function effects on the WAVE signaling pathway and are associated with severe neurological disorders. Ann Neurol 2018;83:794-806., (© 2018 American Neurological Association.)
- Published
- 2018
- Full Text
- View/download PDF
25. Case report of treatment experience with idursulfase beta (Hunterase) in an adolescent patient with MPS II.
- Author
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Ngu LH, Ong Peitee W, Leong HY, and Chew HB
- Abstract
Mucopolysaccharidosis (MPS) II or Hunter syndrome is a chronic, progressive, multi-systemic illness associated with significant morbidity and early mortality. Available evidence in Asian populations shows that Hunter syndrome has a mean age of onset of 2 to 5 years and a life expectancy of 13 years in more severely affected individuals, with respiratory failure reported as the leading cause of death. Enzyme replacement therapy (ERT) with idursulfase (Elaprase, Shire Pharmaceuticals) and idursulfase beta (Hunterase, Green Cross Corp) are the only approved treatment for patients with MPS II. While these agents have the same amino acids, they have different glycosylation patterns because they are produced in different cell lines via different manufacturing processes. In previous studies, the beneficial effects of idursulfase beta have been confirmed in patients up to 35 years of age, without serious treatment-related safety concerns. The major drawbacks associated with ERT include the potential development of serious infusion-related anaphylactic reactions and up to 50% of treated patients develop anti-IDS antibodies. Here we report the case of a 13-year-old Malaysian patient with attenuated MPS II who developed troublesome infusion-associated reactions while receiving idursulfase treatment but tolerated and responded favorably to idursulfase beta.
- Published
- 2017
- Full Text
- View/download PDF
26. CFTR founder mutation causes protein trafficking defects in Chinese patients with cystic fibrosis.
- Author
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Leung GK, Ying D, Mak CC, Chen XY, Xu W, Yeung KS, Wong WL, Chu YW, Mok GT, Chau CS, McLuskey J, Ong WP, Leong HY, Chan KY, Yang W, Chen JH, Li AM, Sham PC, Lau YL, Chung BH, and Lee SL
- Abstract
Background: Cystic fibrosis (CF) is a rare condition in Asians. Since 1985, only about 30 Chinese patients have been reported with molecular confirmation., Method: Using our in-house next-generation sequencing (NGS) pipeline for childhood bronchiectasis, we identified disease-causing CFTR mutations in CF patients in Hong Kong. After identifying p.I1023R in multiple patients, haplotype analysis was performed with genome-wide microarray to ascertain the likelihood of this being a founder mutation. We also assessed the processing and gating activity of the mutant protein by Western hybridization and patch-clamp test., Results: Molecular diagnoses were confirmed in four patients, three of whom shared a missense mutation: CFTR :c.3068T>G:p.I1023R. The results suggested that p.I1023R is a founder mutation in southern Han Chinese. In addition, the processing and gating activity of the mutant protein was assessed by gel electrophoresis and a patch-clamp test. The mutant protein exhibited trafficking defects, suggesting that the dysfunction is caused by reduced cell surface expression of the fully glycosylated proteins., Conclusion: Together with other previously reported mutations, the specific founder mutation presented herein suggests a unique CFTR mutation spectrum in the southern Chinese populations, and this finding has vital implications for improving molecular testing and mutation-specific treatments for Chinese patients with CF.
- Published
- 2016
- Full Text
- View/download PDF
27. Biallelic TBCD Mutations Cause Early-Onset Neurodegenerative Encephalopathy.
- Author
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Miyake N, Fukai R, Ohba C, Chihara T, Miura M, Shimizu H, Kakita A, Imagawa E, Shiina M, Ogata K, Okuno-Yuguchi J, Fueki N, Ogiso Y, Suzumura H, Watabe Y, Imataka G, Leong HY, Fattal-Valevski A, Kramer U, Miyatake S, Kato M, Okamoto N, Sato Y, Mitsuhashi S, Nishino I, Kaneko N, Nishiyama A, Tamura T, Mizuguchi T, Nakashima M, Tanaka F, Saitsu H, and Matsumoto N
- Subjects
- Adolescent, Age of Onset, Amino Acid Sequence, Animals, Brain Diseases pathology, Brain Diseases physiopathology, Child, Child, Preschool, Drosophila melanogaster genetics, Exome, Female, Frameshift Mutation genetics, GTP-Binding Proteins metabolism, Humans, Infant, Infant, Newborn, Male, Microtubule-Associated Proteins chemistry, Microtubule-Associated Proteins metabolism, Microtubules metabolism, Molecular Chaperones genetics, Molecular Chaperones metabolism, Neurodegenerative Diseases pathology, Neurodegenerative Diseases physiopathology, Pedigree, RNA Splice Sites genetics, Tubulin metabolism, Young Adult, Alleles, Brain Diseases genetics, Microtubule-Associated Proteins genetics, Mutation genetics, Neurodegenerative Diseases genetics
- Abstract
We describe four families with affected siblings showing unique clinical features: early-onset (before 1 year of age) progressive diffuse brain atrophy with regression, postnatal microcephaly, postnatal growth retardation, muscle weakness/atrophy, and respiratory failure. By whole-exome sequencing, we identified biallelic TBCD mutations in eight affected individuals from the four families. TBCD encodes TBCD (tubulin folding co-factor D), which is one of five tubulin-specific chaperones playing a pivotal role in microtubule assembly in all cells. A total of seven mutations were found: five missense mutations, one nonsense, and one splice site mutation resulting in a frameshift. In vitro cell experiments revealed the impaired binding between most mutant TBCD proteins and ARL2, TBCE, and β-tubulin. The in vivo experiments using olfactory projection neurons in Drosophila melanogaster indicated that the TBCD mutations caused loss of function. The wide range of clinical severity seen in this neurodegenerative encephalopathy may result from the residual function of mutant TBCD proteins. Furthermore, the autopsied brain from one deceased individual showed characteristic neurodegenerative findings: cactus and somatic sprout formations in the residual Purkinje cells in the cerebellum, which are also seen in some diseases associated with mitochondrial impairment. Defects of microtubule formation caused by TBCD mutations may underlie the pathomechanism of this neurodegenerative encephalopathy., (Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
28. N-Carbamylglutamate Is an Effective Treatment for Acute Neonatal Hyperammonaemia in a Patient with Methylmalonic Aciduria.
- Author
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Yap S, Leong HY, Abdul Aziz F, Hassim H, Sthaneshwar P, Teh SH, Abdullah IS, Ngu LH, and Mohamed Z
- Subjects
- Administration, Oral, Glutamates administration & dosage, Humans, Infant, Newborn, Male, Nutritional Support, Treatment Outcome, Amino Acid Metabolism, Inborn Errors complications, Ammonia blood, Glutamates therapeutic use, Hyperammonemia drug therapy
- Abstract
N-carbamylglutamate (NCG) has been used in combination with ammonia scavengers (sodium benzoate, sodium phenylbutyrate) and dialysis to treat hyperammonaemia in methylmalonic aciduria (MMA). The sole use of NCG for acute neonatal hyperammonaemia secondary to MMA is demonstrated in a neonate presenting at day 9 with encephalopathy, severe metabolic acidosis, hyperammonaemia (1,089 μmol/l), ketonuria and urinary methylmalonic acids. Emergency treatment included discontinuing protein feeds, providing high calories, carnitine and hydroxocobalamin. NCG 200 mg given at 0 and 90 min decreased plasma ammonia dramatically from 1,089 to 567 µmol/l at 90 min and further to 236 µmol/l at 6 h. Normalisation of ammonia was achieved at 12 h with two further doses of NCG 100 mg. This allowed for early re-institution of feeds at 14 h, followed by metabolic stabilization and recovery. Due to the effectiveness of NCG in this case, the use of the more invasive conventional ammonia-lowering therapeutic options could be avoided., (© 2016 S. Karger AG, Basel.)
- Published
- 2016
- Full Text
- View/download PDF
29. Whole exome sequencing is an efficient, sensitive and specific method for determining the genetic cause of short-rib thoracic dystrophies.
- Author
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McInerney-Leo AM, Harris JE, Leo PJ, Marshall MS, Gardiner B, Kinning E, Leong HY, McKenzie F, Ong WP, Vodopiutz J, Wicking C, Brown MA, Zankl A, and Duncan EL
- Subjects
- Abnormalities, Multiple diagnosis, Adaptor Proteins, Signal Transducing genetics, Adult, Carrier Proteins genetics, Cell Cycle Proteins genetics, Child, Child, Preschool, Cytoplasmic Dyneins genetics, Cytoskeletal Proteins, Genotype, Humans, Infant, Newborn, Microtubule-Associated Proteins genetics, NIMA-Related Kinase 1, Protein Serine-Threonine Kinases genetics, Reproducibility of Results, Sensitivity and Specificity, Abnormalities, Multiple genetics, Exome genetics, Genetic Predisposition to Disease genetics, Mutation, Ribs abnormalities, Sequence Analysis, DNA methods, Thorax pathology
- Abstract
Short-rib thoracic dystrophies (SRTDs) are congenital disorders due to defects in primary cilium function. SRTDs are recessively inherited with mutations identified in 14 genes to date (comprising 398 exons). Conventional mutation detection (usually by iterative Sanger sequencing) is inefficient and expensive, and often not undertaken. Whole exome massive parallel sequencing has been used to identify new genes for SRTD (WDR34, WDR60 and IFT172); however, the clinical utility of whole exome sequencing (WES) has not been established. WES was performed in 11 individuals with SRTDs. Compound heterozygous or homozygous mutations were identified in six confirmed SRTD genes in 10 individuals (IFT172, DYNC2H1, TTC21B, WDR60, WDR34 and NEK1), giving overall sensitivity of 90.9%. WES data from 993 unaffected individuals sequenced using similar technology showed two individuals with rare (minor allele frequency <0.005) compound heterozygous variants of unknown significance in SRTD genes (specificity >99%). Costs for consumables, laboratory processing and bioinformatic analysis were
- Published
- 2015
- Full Text
- View/download PDF
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