MyMedR

Fulltext An outbreak of Bacillus cereus food poisoning in a school hostel, Klang

Rampal L, Jegathesan M, Lim YS

Med J Malaysia, 1984 Jun;39(2):116-22.

A food poisoning outbreak affected 114 female Malay students staying in a religious secondary school hostel in Klang. The students developed an illness mainly characterized by abdominal pain, nausea, vomiting and giddiness. The median incubation period in this outbreak was 2.5 hours. Laboratory examination of suspected food revealed 2.3 X10^6 Bacillus cereus organisms per gram of fried noodles. B. cereus was determined as the probable cause of this outbreak and the fried. noodles the most likely vehicle for the organism. An outbreak of B. cereus food poisoning is being reported in Malaysia for the first time.

Fulltext Salmonella in the soil of kidergarten playgrounds in the Klang District

Jegathesan M, Rampal L, Lim YS

Med J Malaysia, 1983 Dec;38(4):308-10.

PMID: 6599988

A survey on the incidence of Salmonellae in soil was conducted on 12 kindergartens in the Klang District, The organism. was isolated from five (three urban and two rural) kindergartens from one or more soil samples tested. Ten isolates comprising six serotypes, namely, Salmonella bareilly, S. haifa, S. abony, S. weltevreden, S. agona and S. stanley, were encountered. The possible role that these soil isolates may play in the transmission. of salmonellae is discussed. The need to use more than one media in the detection of salmonellae is emphasised.

Fulltext Shigella vulvovaginitis in a three-year-old child: a case report

Cheong YM, Jegathesan M, Lim YS

Med J Malaysia, 1984 Mar;39(1):92-4.

PMID: 6392838

This is a report of a case of vulvovaginitis due to Shigella flexneri in a three-year-old child. This is probably the first documented case of shigella vulvovaginitis In Malaysia. The patient was successfully treated with cotrimoxazole. Extraintestinal infections by Shigella are rare and are briefly reviewed in this article.

Antibiotic resistance and R plasmids in coliforms isolated from some Malaysian cooked foods

Khor SY, Lim YS, Jegathesan M

Southeast Asian J. Trop. Med. Public Health, 1982 Jun;13(2):270-4.

PMID: 7147009

Forty samples of Malaysian cooked foods were examined for the presence of antibiotic-resistant coliforms and R plasmids. Twenty seven (68%) of the foods had antibiotic-resistant coliforms and 5 (13%) had R plasmids. Nineteen samples (48%) had total bacterial counts over 10(6) per gm and in 5 samples, no coliforms were detected. Our findings show that cooked food may be one possible way by which R plasmids are spread. The control of the spread of R plasmids is discussed.

Enterotoxin production by Staphylococcus aureus strains isolated from humans, foods and animals in Malaysia

Lim YS, Jegathesan M, Koay AS

Southeast Asian J. Trop. Med. Public Health, 1982 Mar;13(1):133-7.

PMID: 7112212

Enterotoxin production by strains of Staphylococcus aureus isolated from human, food and animal sources was investigated. Of the 130 isolates studied, 27 (20.8%) were found to be enterotoxigenic. The most common enterotoxin detected from human sources was enterotoxin C whereas enterotoxin B occurred more frequently in staphylococcal strains of food origin. The 2 enterotoxigenic strains, from animals isolated from a dog and a goat, produced enterotoxins A and C, respectively. Enterotoxin E was not detected alone from any of the enterotoxigenic strains studied, but occurred together with other enterotoxins. The need to detect enterotoxin in staphylococcal strains and in suspected foods for the confirmation of staphylococcal food poisoning is discussed.

Fulltext Campylobacter jejuni as a cause of diarrhoea in Kuala Lumpur, Malaysia

Lim YS, Jegathesan M, Wong YH

Med J Malaysia, 1984 Dec;39(4):285-8.

PMID: 6544934

The incidence of Campylobacter jejuni in patients with and without diarrhoea was studied in Kuala Lumpur, Malaysia. C. jejuni was recovered from 3.8% and 4.3% of diarrhoeal stools of children and adults, respectively. From the patients without diarrhoea, the relative isolation rates for children and adults were 2.6% and 0%, respectively. Dual infections occurred in two children, with Salmonella and enteropathogenic Escherichia coli being the other enteric pathogen in each case. Cary-Blair medium was found to be an effective transport medium in recovering C. jejuni. Campylobacter enteritis occurred in patients of various age groups, indicating that this organism should be sought routinely by diagnostic laboratories in faecal specimens from patients with diarrhoea.

Fulltext The impact of four processing methods on trypsin-, chymotrypsin- and alpha-amylase inhibitors present in underutilised legumes

Choi WC, Parr T, Lim YS

J Food Sci Technol, 2019 Jan;56(1):281-289.

PMID: 30728570 DOI: 10.1007/s13197-018-3488-0

The global trend in increasing plant-based protein diets due to health and ideological reasons, has created an increased demand for food legumes that exceeds current production. To meet this demand, it is timely to reduce relying solely on soybean, and explore the potential of the underutilised legumes that are cultivated regionally. Underutilised legumes are rich in protein, carbohydrates and other nutrients that are essential for consumer. However, relatively little is known about their anti-nutritional properties and processing methods. Anti-nutritional factors (ANFs) such as enzyme inhibitors are prevalent in legumes and may interfere with digestibility and nutrient absorption. Nevertheless, an optimised food processing method will overcome this challenge and warrant a safe inclusion of legume in plant-based protein diets. Hence current study aimed to optimise the food processing methods (soaking, wet heating, autoclaving and freezing) and evaluate their efficiency in eliminating the enzyme inhibitors [trypsin, chymotrypsin (CIA) and α-amylase (AIA) inhibitors] present in seven underutilised legumes. Current study showed that autoclaving at 121 °C for 15 min reduced the AIA in all underutilised legumes tested. The AIA and CIA of bambara groundnut were successfully inactivated by wet heating at 50 °C for 60 min, and by autoclaving at 121 °C for 15 min. While the CIA of chickpea was successfully inactivated by freezing at - 80 °C for 24 h.

Proteomics in commercial crops: An overview

Tan BC, Lim YS, Lau SE

J Proteomics, 2017 10 03;169:176-188.

PMID: 28546092 DOI: 10.1016/j.jprot.2017.05.018

Proteomics is a rapidly growing area of biological research that is positively affecting plant science. Recent advances in proteomic technology, such as mass spectrometry, can now identify a broad range of proteins and monitor their modulation during plant growth and development, as well as during responses to abiotic and biotic stresses. In this review, we highlight recent proteomic studies of commercial crops and discuss the advances in understanding of the proteomes of these crops. We anticipate that proteomic-based research will continue to expand and contribute to crop improvement.

SIGNIFICANCE: Plant proteomics study is a rapidly growing area of biological research that is positively impacting plant science. With the recent advances in new technologies, proteomics not only allows us to comprehensively analyses crop proteins, but also help us to understand the functions of the genes. In this review, we highlighted recent proteomic studies in commercial crops and updated the advances in our understanding of the proteomes of these crops. We believe that proteomic-based research will continue to grow and contribute to the improvement of crops.

When polymyositis meets Graves' disease: A rare case report

Chai ST, Lim YS, Achok HN

Med J Malaysia, 2021 Nov;76(6):937-940.

PMID: 34806691

Polymyositis is rarely associated with Graves' disease. A 22- year-old woman was admitted for progressively worsening proximal muscle weakness of both upper and lower extremities. One month prior to admission, she was diagnosed with thyrotoxicosis and prescribed carbimazole 10mg twice daily. Neurological examination confirmed proximal myopathy and blood investigations revealed marked elevation of muscle enzymes, particularly creatine kinase. Electromyography demonstrated myopathic changes while right quadriceps muscle biopsy showed only traces of inflammatory myopathy. She was treated with pulsed intravenous methylprednisolone followed by tapering doses of oral prednisolone, which was eventually down-titrated to 5mg daily during subsequent clinic visits. The initial clinical improvement that she exhibited did not persist despite being rendered euthyroid. She was readmitted approximately one year later with the same complaint. A second course of intravenous methylprednisolone brought about clinical improvement as well as reduction of creatine kinase levels. A diagnosis of polymyositis was then made, for which she was managed with oral prednisolone 20mg daily in combination with gradual up-titration of azathioprine. She continued to show clinical and biochemical improvements during follow-ups. Polymyositis should be considered in the diagnostic workup of proximal myopathy in a patient with Graves' disease, especially in the setting of markedly raised muscle enzymes.

Fulltext Plesiomonas shigelloides associated with diarrhoeal disease in Malaysian children

Lim YS, Young LJ, Balakrishnan S

Singapore Med J, 1987 Dec;28(6):534-6.

PMID: 3441796

Plesiomonas shigelloides was isolated from 5 (2.1%) of the 234 children with diarrhoea and none of the 230 controls. In one child, the organism was found in association with Salmonella. Two strains had Shigella sonnei phase I antigen. All the strains were susceptible to the aminoglycosides, cephalosporins, nalidixic acid, nitrofurantoin, chloramphenicol and cotrimoxazole; but resistant to the penicillins. Alkaline peptone water enrichment subcultured to desoxycholale citrate agar proved to be a useful method for isolating this organism from faeces. As the roie of P. shigelloides in causing gastrointestinal disease remains controversial, further studies are necessary to determine its enteropathogenicily.

Fulltext Serological detection of enterotoxin from food poisoning strains of Staphylococcus aureus isolated in Malaysia

Lim YS, Jegathesan M, Koay AS

Singapore Med J, 1985 Jun;26(3):304-6.

PMID: 4048994

Cultures of Staphylococcus aureus from eight food poisoning incidents in Malaysia were examined for their ability to produce enterotoxins. Five of the eight strains were found to be enterotoxigenic, the enterotoxins detected being A and E (three strains), A and C (one strain), and C (one strain). Penicillinase production was observed in four of the five enterotoxigenic strains; the penicillin·sensitive strain was also found to be coagulase-negative. The bacteriological and epidemiological investigations for confirming staphylococcal food poisoning are presented. The preventive measures to be taken in reducing such outbreaks are emphasized.

Fulltext The occurrence of enterotoxigenic strains of Staphylococcus aureus in foods

Lim YS, Jegathesan M, Koay AS, Kang SH

Med J Malaysia, 1983 Mar;38(1):27-30.

PMID: 6633330

Enterotoxin production by strains of Staphylococcus aureus isolated from foods unconnected with outbreaks offood poisoning was investigated. Twenty-three percent of 217 strains examined produced enterotoxins A, B, C, D or E. Enterotoxin C was found to occur most frequently. Enterotoxin A was not detected alone from any of the strains examined, but occurred together with other enterotoxins. The overall number of strains isolated from raw foods which produced one or more enterotoxins was higher than that for cooked foods. Antibiotic sensitivities were unrelated to enterotoxin production and no correlation could be found between methicillin resistance and enterotoxigenicity.

Fulltext The isolation of Salmonella from raw, cooked and dried foods

Lim YS, Khor SY, Jegathesan M, Kang SH

Med J Malaysia, 1984 Sep;39(3):220-4.

PMID: 6544923

Between June 1977 and May 1982, 2,291 samples of raw, cooked and dried foods were examined for the presence of Salmonella. Of these samples, 43 were positive, isolations being made from raw foods (4.8%) and cooked foods (0.4%) but not from dried foods. 14 Salmonella seratypes were isolated, Salmonella anatum being the most predominant. The significance of these isolations is discussed and the need for consumer education to reduce the incidence of human salmonellosis is emphasised.

Fulltext In-situ electrochemically deposited polypyrrole nanoparticles incorporated reduced graphene oxide as an efficient counter electrode for platinum-free dye-sensitized solar cells

Lim SP, Pandikumar A, Lim YS, Huang NM, Lim HN

Sci Rep, 2014;4:5305.

PMID: 24930387 DOI: 10.1038/srep05305

This paper reports a rapid and in-situ electrochemical polymerization method for the fabrication of polypyrrole nanoparticles incorporated reduced graphene oxide (rGO@PPy) nanocomposites on a ITO conducting glass and its application as a counter electrode for platinum-free dye-sensitized solar cell (DSSC). The scanning electron microscopic images show the uniform distribution of PPy nanoparticles with diameter ranges between 20 and 30 nm on the rGO sheets. The electrochemical studies reveal that the rGO@PPy has smaller charge transfer resistance and similar electrocatalytic activity as that of the standard Pt counter electrode for the I₃(-)/I(-) redox reaction. The overall solar to electrical energy conversion efficiency of the DSSC with the rGO@PPy counter electrode is 2.21%, which is merely equal to the efficiency of DSSC with sputtered Pt counter electrode (2.19%). The excellent photovoltaic performance, rapid and simple fabrication method and low-cost of the rGO@PPy can be potentially exploited as a alternative counter electrode to the expensive Pt in DSSCs.

Seroprevalence and risk factors for influenza A viruses in pigs in Peninsular Malaysia

Suriya R, Hassan L, Omar AR, Aini I, Tan CG, Lim YS, et al.

Zoonoses Public Health, 2008 Sep;55(7):342-51.

PMID: 18667027 DOI: 10.1111/j.1863-2378.2008.01138.x

Following a series of H5N1 cases in chickens and birds in a few states in Malaysia, there was much interest in the influenza A viruses subtypes that circulate among the local pig populations. Pigs may act as a mixing vessel for avian and mammal influenza viruses, resulting in new reassorted viruses. This study investigated the presence of antibodies against influenza H1N1 and H3N2 viruses in pigs from Peninsular Malaysia using Herdcheck Swine Influenza H1N1 and H3N2 Antibody Test Kits. At the same time, the presence of influenza virus was examined from the nasal swabs of seropositive pigs by virus isolation and real time RT-PCR. The list of pig farms was obtained from the headquarters of the Department of Veterinary Services, Malaysia, and pig herds were selected randomly from six of 11 states in Peninsular Malaysia. A total of 727 serum and nasal swab samples were collected from 4- to 6-month-old pigs between May and August 2005. By ELISA, the seroprevalences of swine influenza H1N1 and H3N2 among pigs were 12.2% and 12.1% respectively. Seropositivity for either of the virus subtypes was detected in less than half of the 41 sampled farms (41.4%). Combination of both subtypes was detected in 4% of all pigs and in 22% of sampled farms. However, no virus or viral nucleic acid was detected from nasal samples. This study identified that the seropositivity of pigs to H1N1 and H3N2 based on ELISA was significantly associated with factors such as size of farm, importation or purchase of pigs, proximity of farm to other pig farms and the presence of mammalian pets within the farm.

Engineering S. oneidensis for Performance Improvement of Microbial Fuel Cell-a Mini Review

Leung DHL, Lim YS, Uma K, Pan GT, Lin JH, Chong S, et al.

Appl Biochem Biotechnol, 2021 Apr;193(4):1170-1186.

PMID: 33200267 DOI: 10.1007/s12010-020-03469-6

Microbial fuel cell (MFC) is a promising technology that utilizes exoelectrogens cultivated in the form of biofilm to generate power from various types of sources supplied. A metal-reducing pathway is utilized by these organisms to transfer electrons obtained from the metabolism of substrate from anaerobic respiration extracellularly. A widely established model organism that is capable of extracellular electron transfer (EET) is Shewanella oneidensis. This review highlights the strategies used in the transformation of S. oneidensis and the recent development of MFC in terms of intervention through genetic modifications. S. oneidensis was genetically engineered for several aims including the study on the underlying mechanisms of EET, and the enhancement of power generation and wastewater treating potential when used in an MFC. Through engineering S. oneidensis, genes responsible for EET are identified and strategies on enhancing the EET efficiency are studied. Overexpressing genes related to EET to enhance biofilm formation, mediator biosynthesis, and respiration appears as one of the common approaches.

Fulltext Cefepime plus amikacin as an initial empirical therapy of febrile neutropenia in paediatric cancer patients

Hamidah A, Lim YS, Zulkifli SZ, Zarina AL, Nordiah AJ, Jamal R

Singapore Med J, 2007 Jul;48(7):615-9.

PMID: 17609821

We evaluated the efficacy of cefepime in association with amikacin in the initial empirical therapy of febrile neutropenic children.

Fulltext Efficacy of a Text-Based Mental Health Coaching App in Improving the Symptoms of Stress, Anxiety, and Depression: Randomized Controlled Trial

Lim YS, Quek JH, Ching XW, Lim DTR, Lim KG, Thuraisingham C, et al.

JMIR Form Res, 2023 Sep 22;7:e46458.

PMID: 37738081 DOI: 10.2196/46458

BACKGROUND: Stress, anxiety, and depression are major mental health concerns worldwide. A wide variety of digital mental health interventions have demonstrated efficacy in improving one's mental health status, and digital interventions that involve some form of human involvement have been shown to demonstrate greater efficacy than self-guided digital interventions. Studies demonstrating the efficacy of digital mental health interventions within the Asian region are scarce.

OBJECTIVE: This study aimed to investigate the potential efficacy of the digital mental health intervention, ThoughtFullChat, which consists of one-on-one, asynchronous, text-based coaching with certified mental health professionals and self-guided tools, in improving self-reported symptoms of depression, anxiety, and stress. The study also aims to examine the potential differences in efficacy among occupational subgroups and between sexes.

METHODS: A randomized controlled study was conducted among housemen (trainee physicians), students, faculty members, and corporate staff at International Medical University, Malaysia. A total of 392 participants were enrolled and randomized to the intervention (n=197, 50.3%) and control (n=195, 49.7%) groups. Depression, anxiety, and stress symptoms were measured using the Depression, Anxiety, and Stress Scale-21 items at baseline and after the 3-month intervention period. The Satisfaction with Life Scale and Brief Resilience Scale were also included, along with a questionnaire about demographics.

RESULTS: Significant decrease was observed in depression (P=.02) and anxiety (P=.002) scores in the intervention group. A subgroup (corporate staff) also demonstrated significant decrease in stress (P=.005) alongside depression (P=.006) and anxiety (P=.002). Females showed significant improvements in depression (P=.02) and anxiety (P

Fulltext Self-Healing Sulfonated Poly(ether ether ketone)-Based Polymer Electrolyte Membrane for Direct Methanol Fuel Cells: Effect of Solvent Content

Tai MH, Thiam HS, Tee SF, Lim YS, Saw LH, Lai SO

Polymers (Basel), 2023 Dec 08;15(24).

PMID: 38139893 DOI: 10.3390/polym15244641

Proton exchange membranes (PEMs) with superior characteristics are needed to advance fuel cell technology. Nafion, the most used PEM in direct methanol fuel cells (DMFCs), has excellent proton conductivity but suffers from high methanol permeability and long-term performance degradation. Thus, this study aimed to create a healable PEM with improved durability and methanol barrier properties by combining sulfonated poly(ether ether ketone) (SPEEK) and poly-vinyl alcohol (PVA). The effect of changing the N,N-dimethylacetamide (DMAc) solvent concentration during membrane casting was investigated. Lower DMAc concentrations improved water absorption and, thus, membrane proton conductivity, but methanol permeability increased correspondingly. For the best trade-off between these two characteristics, the blend membrane with a 10 wt% DMAc solvent (SP10) exhibited the highest selectivity. SP10 also showed a remarkable self-healing capacity by regaining 88% of its pre-damage methanol-blocking efficiency. The ability to self-heal decreased with the increasing solvent concentration because of the increased crosslinking density and structure compactness, which reduced chain mobility. Optimizing the solvent concentration during membrane preparation is therefore an important factor in improving membrane performance in DMFCs. With its exceptional methanol barrier and self-healing characteristics, the pioneering SPEEK/PVA blend membrane may contribute to efficient and durable fuel cell systems.

Fulltext Integration of an on-axis general sun-tracking formula in the algorithm of an open-loop sun-tracking system

Chong KK, Wong CW, Siaw FL, Yew TK, Ng SS, Liang MS, et al.

Sensors (Basel), 2009;9(10):7849-65.

PMID: 22408483 DOI: 10.3390/s91007849

A novel on-axis general sun-tracking formula has been integrated in the algorithm of an open-loop sun-tracking system in order to track the sun accurately and cost effectively. Sun-tracking errors due to installation defects of the 25 m(2) prototype solar concentrator have been analyzed from recorded solar images with the use of a CCD camera. With the recorded data, misaligned angles from ideal azimuth-elevation axes have been determined and corrected by a straightforward changing of the parameters' values in the general formula of the tracking algorithm to improve the tracking accuracy to 2.99 mrad, which falls below the encoder resolution limit of 4.13 mrad.

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