Displaying publications 1 - 20 of 77 in total

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  1. Lim EL, Seah TC, Koe XF, Wahab HA, Adenan MI, Jamil MF, et al.
    Toxicol In Vitro, 2013 Mar;27(2):812-24.
    PMID: 23274770 DOI: 10.1016/j.tiv.2012.12.014
    CYP450 enzymes are key determinants in drug toxicities, reduced pharmacological effect and adverse drug reactions. Mitragynine, an euphoric compound was evaluated for its effects on the expression of mRNAs encoding CYP1A2, CYP2D6 and CYP3A4 and protein expression and resultant enzymatic activity. The mRNA and protein expression of CYP450 isoforms were carried out using an optimized multiplex qRT-PCR assay and Western blot analysis. CYP1A2 and CYP3A4 enzyme activities were evaluated using P450-Glo™ assays. The effects of mitragynine on human CYP3A4 protein expression were determined using an optimized hCYP3A4-HepG2 cell-based assay. An in silico computational method to predict the binding conformation of mitragynine to the active site of the CYP3A4 enzyme was performed and further validated using in vitro CYP3A4 inhibition assays. Mitragynine was found to induce mRNA and protein expression of CYP1A2. For the highest concentration of 25 μM, induction of mRNA was approximately 70% that of the positive control and was consistent with the increased CYP1A2 enzymatic activity. Thus, mitragynine is a significant in vitro CYP1A2 inducer. However, it appeared to be a weak CYP3A4 inducer at the transcriptional level and a weak CYP3A4 enzyme inhibitor. It is therefore, unlikely to have any significant clinical effects on CYP3A4 activity.
  2. Tay YL, Teah YF, Chong YM, Jamil MFA, Kollert S, Adenan MI, et al.
    Toxicol Appl Pharmacol, 2016 08 15;305:22-39.
    PMID: 27260674 DOI: 10.1016/j.taap.2016.05.022
    Mitragyna speciosa Korth is known for its euphoric properties and is frequently used for recreational purposes. Several poisoning and fatal cases involving mitragynine have been reported but the underlying causes remain unclear. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. On the other hand, IK1, a Kir current mediated by Kir2.1 channel and IKACh, a receptor-activated Kir current mediated by GIRK channel are also known to be important in maintaining the cardiac function. This study investigated the effects of mitragynine on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells and Xenopus oocytes. The effects on Kir2.1 and GIRK channels currents were also determined in the oocytes. The hERG tail currents following depolarization pulses were inhibited by mitragynine with an IC50 value of 1.62μM and 1.15μM in the transfected cell line and Xenopus oocytes, respectively. The S6 point mutations of Y652A and F656A attenuated the inhibitor effects of mitragynine, indicating that mitragynine interacts with these high affinity drug-binding sites in the hERG channel pore cavity which was consistent with the molecular docking simulation. Interestingly, mitragynine does not affect the hERG expression at the transcriptional level but inhibits the protein expression. Mitragynine is also found to inhibit IKACh current with an IC50 value of 3.32μM but has no significant effects on IK1. Blocking of both hERG and GIRK channels may cause additive cardiotoxicity risks.
  3. Tan HK, Muhammad TST, Tan ML
    Toxicol Appl Pharmacol, 2016 06 01;300:55-69.
    PMID: 27049118 DOI: 10.1016/j.taap.2016.03.017
    14-Deoxy-11,12-didehydroandrographolide (14-DDA), a major diterpenoid isolated from Andrographis paniculata (Burm.f.) Nees, is known to be cytotoxic and elicits a non-apoptotic cell death in T-47D breast carcinoma cells. In this study, the mechanistic toxicology properties of 14-DDA in T-47D cells were further investigated. 14-DDA is found to induce the formation of endoplasmic reticulum (ER) vacuoles and autophagosomes, with concurrent upregulation of LC3-II in the breast carcinoma cells. It stimulated an increase in cytosolic calcium concentration and caused a collapse in mitochondrial membrane potential in these cells. In addition, both DDIT3 and GADD45A, molecules implicated in ER stress pathway, were significantly upregulated. DDIT3 knockdown suppressed the formation of both ER vacuoles and autophagosomes, indicating that 14-DDA-induced ER stress and autophagy is dependent on this transcription factor. Collectively, it is possible that GADD45A/p38 MAPK/DDIT3 pathway is involved in the 14-DDA-induced ER-stress-mediated autophagy in T-47D cells.
  4. Tan ML, Gassman PW, Liang J, Haywood JM
    Sci Total Environ, 2021 Nov 15;795:148915.
    PMID: 34328938 DOI: 10.1016/j.scitotenv.2021.148915
    Alternative climate products, such as gauge-based gridded data, ground-based weather radar, satellite precipitation and climate reanalysis products, are being increasingly applied for hydrological modelling. This review aims to summarize the studies that have evaluated alternative climate products within Soil and Water Assessment Tool (SWAT) applications and to propose future research directions, primarily for modelers who wish to study limited gauge, ungauged or transnational river basins. A total of 126 articles have been identified since 2004, the majority of which have been published within the last five years. About 58% of the studies were conducted in Asia, mostly in China and India, while another 14% were reported for United States studies. CFSR and TRMM are the most popular applied products in SWAT modelling, followed by PERSIANN, CMADS, APHRODITE, CHIRPS and NEXRAD. Generally, the performance of climate products is region-dependent; e.g., CFSR typically performs well in the United States and South America, but performs more poorly for Asia, Africa and mountainous basin conditions, as compared to other products. In contrast, the CMADS, TRMM, APRHODITE and NEXRAD have shown the strongest capability for supporting SWAT modelling in these regions. However, most of the evaluated products contain only precipitation input; therefore, merging reliable precipitation with CFSR-temperature is recommended for hydro-climatic modelling. Future research directions include: (1) examination of optimal combinations; e.g. CHIRPS-precipitation and CFSR-temperature, for simulating streamflow in different types of river basins; (2) development of a standardized validation scheme which incorporates the commonly accepted products, statistical approaches and temperature variables; (3) further evaluation of existing climate data products to accurately capture extreme events, pattern and indices as well as WGEN statistics; (4) improvement of climate data in terms of averaging approach, bias correction and additional factors or indices integration; and (5) bias correction of CMIP6 climate projections using the optimal climate data combinations.
  5. Chee SY, Tan ML, Tew YL, Sim YK, Yee JC, Chong AKM
    Sci Total Environ, 2023 Feb 01;858(Pt 2):159889.
    PMID: 36328260 DOI: 10.1016/j.scitotenv.2022.159889
    Cities all over the world are edging further into the ocean. Coastal reclamation is a global conservation issue with implications for ocean life, ecosystems, and human well-being. Using Malaysia as a case study, the coastal reclamation trends over three decades (1991-2021) were mapped using Landsat images and Normalized Difference Water Index (NDWI) via the Google Earth Engine platform. The changes in drivers and impacts of these coastal expansions throughout the decades were also reviewed. Twelve out of the 14 states in Malaysia had planned, active, or completed reclamations on their shorelines. Between 1991 and 2021, an absolute area of 82.64 km2 has been or will be reclaimed should all the projects be completed. The most reported driver for coastal expansion in Malaysia is for development and modernization (41 %), followed by rise in human population (20 %), monetary gains from the development of prime land (15 %), and agriculture and aquaculture activities (9 %). Drivers such as reduction of construction costs, financial advantage of prime land, oil and gas, advancement of technology, and tourism (Malaysia My Second Home (MM2H)) had only started occurring within the last decade, while others have been documented since the 1990's. Pollution is the most reported impact (24 %) followed by disruption of livelihoods, sources of income and human well-being (21 %), destruction of natural habitats (17 %), decrease in biodiversity (11 %), changes in landscapes (10 %), erosion / accretion (8 %), threat to tourism industry (6 %), and exposure to wave surges (3 %). Of these, changes in landscape, shoreline alignment, seabed contour, and coastal groundwater, as well as wave surges had only started to surface as impacts in the last two decades. Efforts to protect existing natural coastal and marine ecosystems, restore degraded ones, and fund endeavours that emphasize nature is needed to support sustainable development goals for the benefit of future generations.
  6. Liu C, Zhang F, Jim CY, Johnson VC, Tan ML, Shi J, et al.
    Sci Total Environ, 2023 Mar 29;878:163127.
    PMID: 37001663 DOI: 10.1016/j.scitotenv.2023.163127
    Suspended particulate matter (SPM) in the brackish Ebinur Lake of arid northwest China profoundly affect its water quality and watershed habitat quality. However, the actual driving mechanisms of the Lake's SPM changes remain unclear. Therefore, the purpose of this study is to explore the controlling factors driving the variability of SPM in the Ebinur Lake. This study constructed month-by-month SPM maps of Ebinur Lake based on time-series remote-sensing imageries and SPM inversion model. Thirty-four factors that might influence SPM changes were extracted, and the Partial Least Squares Structural Equation Modeling (PLS-SEM), suitable for complex relationships and factor interactions, was applied to identify the relative influence of each factor quantitatively. The results showed: (1) a clear increasing trend of SPM concentration in Ebinur Lake from 2011 to 2020; (2) that SPM changes were influenced by external and internal factors, explaining 48.2 % and 46.9 % of the changes, respectively; (3) that, to the external factors, meteorological factors exerted the greatest influence on SPM (relative contribution of 38.9 %); that, to the internal factors, water salinity imposed the greatest influence on SPM (relative contribution of 43.3 %); (4) that, among the meteorological factors, the measured variable Alashankou wind speed expressed the most significant positive effect on SPM (weighting coefficient of 0.894), and sulfate generated the strongest positive effect on SPM (weighting coefficient of 0.791) among the water salinity factors. Hence, the quantitative identification of drivers of SPM changes in Ebinur Lake could provide a new perspective to investigate the driving mechanisms of lake water quality in arid areas and inform their sustainable restoration and management.
  7. Mundada P, Tan ML, Soh AW
    Med J Malaysia, 2015 Aug;70(4):256-8.
    PMID: 26358025
    Although it is common to have extra-hepatic metastasis of hepatocellular carcinoma (HCC) at the time of presentation, it is extremely rare to have extra-hepatic metastatic HCC without a detectable primary in the liver. We report a unique case in which a patient presented with bilateral large adrenal masses which were subsequently proven to be metastases from HCC. However, there was no tumour seen in the liver on imaging.
  8. Foong SC, Hwang YC, Foong WC, Tan ML
    Med J Malaysia, 2021 Nov;76(6):924-926.
    PMID: 34806687
    Methaemoglobinaemia occurs when there is >1% methaemoglobin in erythrocytes. In an infant, they can present either congenitally or in an acquired form. We present a rare case of methaemoglobinaemia presenting simultaneously in a mother and infant pair. The mother and infant were discharged well on Day-4 post-delivery with both mother and baby recording oxygen saturation levels of 100%. On Day-7, during a routine clinic visit, they were incidentally found to be centrally cyanosed. There were no other abnormalities. On investigation, the methaemoglobin levels were elevated in the infant (23.9%) and mother (14.3%). Treatment with ascorbic acid normalised mother's methaemoglobin levels; but baby's levels remained high until the administration of oral methylene blue. Both baby and mother remained well and pink at last follow-up at 2 years 8 months of age. This case illustrates difficulties in ascertaining the cause of methaemoglobinaemia. Postdelivery, the mother-neonate pair were pink, and their haemoglobin electrophoresis were normal, hence it was unlikely to be congenital methaemoglobinaemia. The team could not identify any triggering factors for acquired methaemoglobinaemia. There was also the uncertainty of the necessity to treat the baby. This is because treatment is not without harmful effects and despite the high methaemoglobin levels, the infant was otherwise well. Only a single published paper recommended that high methaemoglobin levels must be treated, and the recommendation was not supported by evidence. Lessons learnt from our case are that neonates with methaemoglobinaemia can be safely treated with oral methylene blue, but more research is needed on the benefitrisk profile of treatment.
  9. Tan ML, Ho JJ, Teh KH
    Cochrane Database Syst Rev, 2016 Sep 28;9:CD009398.
    PMID: 27678554 DOI: 10.1002/14651858.CD009398.pub3
    BACKGROUND: About 5% of school children have a specific learning disorder, defined as unexpected failure to acquire adequate abilities in reading, writing or mathematics that is not a result of reduced intellectual ability, inadequate teaching or social deprivation. Of these events, 80% are reading disorders. Polyunsaturated fatty acids (PUFAs), in particular, omega-3 and omega-6 fatty acids, which normally are abundant in the brain and in the retina, are important for learning. Some children with specific learning disorders have been found to be deficient in these PUFAs, and it is argued that supplementation of PUFAs may help these children improve their learning abilities.

    OBJECTIVES: 1. To assess effects on learning outcomes of supplementation of polyunsaturated fatty acids (PUFAs) for children with specific learning disorders.2. To determine whether adverse effects of supplementation of PUFAs are reported in these children.

    SEARCH METHODS: In November 2015, we searched CENTRAL, Ovid MEDLINE, Embase, PsycINFO, 10 other databases and two trials registers. We also searched the reference lists of relevant articles.

    SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-RCTs comparing PUFAs with placebo or no treatment in children younger than 18 years with specific learning disabilities, as diagnosed in accordance with the fifth (or earlier) edition of theDiagnostic and Statistical Manual of Mental Disorders (DSM-5), or the 10th (or earlier) revision of the International Classification of Diseases (ICD-10) or equivalent criteria. We included children with coexisting developmental disorders such as attention deficit hyperactivity disorder (ADHD) or autism.

    DATA COLLECTION AND ANALYSIS: Two review authors (MLT and KHT) independently screened the titles and abstracts of articles identified by the search and eliminated all studies that did not meet the inclusion criteria. We contacted study authors to ask for missing information and clarification, when needed. We used the GRADE approach to assess the quality of evidence.

    MAIN RESULTS: Two small studies involving 116 children, mainly boys between 10 and 18 years of age, met the inclusion criteria. One study was conducted in a school setting, the other at a specialised clinic. Both studies used three months of a combination of omega-3 and omega-6 supplements as the intervention compared with placebo. Although both studies had generally low risk of bias, we judged the risk of reporting bias as unclear in one study, and as high in the other study. In addition, one of the studies was funded by industry and reported active company involvement in the study.None of the studies reported data on the primary outcomes of reading, writing, spelling and mathematics scores, as assessed by standardised tests.Evidence of low quality indicates that supplementation of PUFAs did not increase the risk of gastrointestinal disturbances (risk ratio 1.43, 95% confidence interval 0.25 to 8.15; two studies, 116 children). Investigators reported no other adverse effects.Both studies reported attention deficit hyperactivity disorder (ADHD)-related behaviour outcomes. We were unable to combine the results in a meta-analysis because one study reported findings as a continuous outcome, and the other as a dichotomous outcome. No other secondary outcomes were reported.We excluded one study because it used a cointervention (carnosine), and five other studies because they did not provide a robust diagnosis of a specific learning disorder. We identified one ongoing study and found three studies awaiting classification.

    AUTHORS' CONCLUSIONS: Evidence is insufficient to permit any conclusions about the effect of PUFAs on the learning abilities of children with specific learning disorders. Well-designed RCTs with clearly defined populations of children with specific learning disorders who have been diagnosed by standardised diagnostic criteria are needed.

  10. Tan ML, Abrams SA, Osborn DA
    Cochrane Database Syst Rev, 2020 Dec 11;12(12):CD013046.
    PMID: 33305822 DOI: 10.1002/14651858.CD013046.pub2
    BACKGROUND: Vitamin D deficiency is common worldwide, contributing to nutritional rickets and osteomalacia which have a major impact on health, growth, and development of infants, children and adolescents. Vitamin D levels are low in breast milk and exclusively breastfed infants are at risk of vitamin D insufficiency or deficiency.

    OBJECTIVES: To determine the effect of vitamin D supplementation given to infants, or lactating mothers, on vitamin D deficiency, bone density and growth in healthy term breastfed infants.

    SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to 29 May 2020 supplemented by searches of clinical trials databases, conference proceedings, and citations.

    SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs in breastfeeding mother-infant pairs comparing vitamin D supplementation given to infants or lactating mothers compared to placebo or no intervention, or sunlight, or that compare vitamin D supplementation of infants to supplementation of mothers.

    DATA COLLECTION AND ANALYSIS: Two review authors assessed trial eligibility and risk of bias and independently extracted data. We used the GRADE approach to assess the certainty of evidence.

    MAIN RESULTS: We included 19 studies with 2837 mother-infant pairs assessing vitamin D given to infants (nine studies), to lactating mothers (eight studies), and to infants versus lactating mothers (six studies). No studies compared vitamin D given to infants versus periods of infant sun exposure. Vitamin D supplementation given to infants: vitamin D at 400 IU/day may increase 25-OH vitamin D levels (MD 22.63 nmol/L, 95% CI 17.05 to 28.21; participants = 334; studies = 6; low-certainty) and may reduce the incidence of vitamin D insufficiency (25-OH vitamin D < 50 nmol/L) (RR 0.57, 95% CI 0.41 to 0.80; participants = 274; studies = 4; low-certainty). However, there was insufficient evidence to determine if vitamin D given to the infant reduces the risk of vitamin D deficiency (25-OH vitamin D < 30 nmol/L) up till six months of age (RR 0.41, 95% CI 0.16 to 1.05; participants = 122; studies = 2), affects bone mineral content (BMC), or the incidence of biochemical or radiological rickets (all very-low certainty). We are uncertain about adverse effects including hypercalcaemia. There were no studies of higher doses of infant vitamin D (> 400 IU/day) compared to placebo. Vitamin D supplementation given to lactating mothers: vitamin D supplementation given to lactating mothers may increase infant 25-OH vitamin D levels (MD 24.60 nmol/L, 95% CI 21.59 to 27.60; participants = 597; studies = 7; low-certainty), may reduce the incidences of vitamin D insufficiency (RR 0.47, 95% CI 0.39 to 0.57; participants = 512; studies = 5; low-certainty), vitamin D deficiency (RR 0.15, 95% CI 0.09 to 0.24; participants = 512; studies = 5; low-certainty) and biochemical rickets (RR 0.06, 95% CI 0.01 to 0.44; participants = 229; studies = 2; low-certainty). The two studies that reported biochemical rickets used maternal dosages of oral D3 60,000 IU/day for 10 days and oral D3 60,000 IU postpartum and at 6, 10, and 14 weeks. However, infant BMC was not reported and there was insufficient evidence to determine if maternal supplementation has an effect on radiological rickets (RR 0.76, 95% CI 0.18 to 3.31; participants = 536; studies = 3; very low-certainty). All studies of maternal supplementation enrolled populations at high risk of vitamin D deficiency. We are uncertain of the effects of maternal supplementation on infant growth and adverse effects including hypercalcaemia. Vitamin D supplementation given to infants compared with supplementation given to lactating mothers: infant vitamin D supplementation compared to lactating mother supplementation may increase infant 25-OH vitamin D levels (MD 14.35 nmol/L, 95% CI 9.64 to 19.06; participants = 269; studies = 4; low-certainty). Infant vitamin D supplementation may reduce the incidence of vitamin D insufficiency (RR 0.61, 95% CI 0.40 to 0.94; participants = 334; studies = 4) and may reduce vitamin D deficiency (RR 0.35, 95% CI 0.17 to 0.72; participants = 334; studies = 4) but the evidence is very uncertain. Infant BMC and radiological rickets were not reported and there was insufficient evidence to determine if maternal supplementation has an effect on infant biochemical rickets. All studies enrolled patient populations at high risk of vitamin D deficiency. Studies compared an infant dose of vitamin D 400 IU/day with varying maternal vitamin D doses from 400 IU/day to > 4000 IU/day. We are uncertain about adverse effects including hypercalcaemia.

    AUTHORS' CONCLUSIONS: For breastfed infants, vitamin D supplementation 400 IU/day for up to six months increases 25-OH vitamin D levels and reduces vitamin D insufficiency, but there was insufficient evidence to assess its effect on vitamin D deficiency and bone health. For higher-risk infants who are breastfeeding, maternal vitamin D supplementation reduces vitamin D insufficiency and vitamin D deficiency, but there was insufficient evidence to determine an effect on bone health. In populations at higher risk of vitamin D deficiency, vitamin D supplementation of infants led to greater increases in infant 25-OH vitamin D levels, reductions in vitamin D insufficiency and vitamin D deficiency compared to supplementation of lactating mothers. However, the evidence is very uncertain for markers of bone health. Maternal higher dose supplementation (≥ 4000 IU/day) produced similar infant 25-OH vitamin D levels as infant supplementation of 400 IU/day. The certainty of evidence was graded as low to very low for all outcomes.

  11. Foong SC, Tan ML, Foong WC, Marasco LA, Ho JJ, Ong JH
    Cochrane Database Syst Rev, 2020 May 18;5(5):CD011505.
    PMID: 32421208 DOI: 10.1002/14651858.CD011505.pub2
    BACKGROUND: Many women express concern about their ability to produce enough milk, and insufficient milk is frequently cited as the reason for supplementation and early termination of breastfeeding. When addressing this concern, it is important first to consider the influence of maternal and neonatal health, infant suck, proper latch, and feeding frequency on milk production, and that steps be taken to correct or compensate for any contributing issues. Oral galactagogues are substances that stimulate milk production. They may be pharmacological or non-pharmacological (natural). Natural galactagogues are usually botanical or other food agents. The choice between pharmacological or natural galactagogues is often influenced by familiarity and local customs. Evidence for the possible benefits and harms of galactagogues is important for making an informed decision on their use.

    OBJECTIVES: To assess the effect of oral galactagogues for increasing milk production in non-hospitalised breastfeeding mother-term infant pairs.

    SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), Health Research and Development Network - Phillippines (HERDIN), Natural Products Alert (Napralert), the personal reference collection of author LM, and reference lists of retrieved studies (4 November 2019).

    SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs (including published abstracts) comparing oral galactagogues with placebo, no treatment, or another oral galactagogue in mothers breastfeeding healthy term infants. We also included cluster-randomised trials but excluded cross-over trials.

    DATA COLLECTION AND ANALYSIS: We used standard Cochrane Pregnancy and Childbirth methods for data collection and analysis. Two to four review authors independently selected the studies, assessed the risk of bias, extracted data for analysis and checked accuracy. Where necessary, we contacted the study authors for clarification.

    MAIN RESULTS: Forty-one RCTs involving 3005 mothers and 3006 infants from at least 17 countries met the inclusion criteria. Studies were conducted either in hospitals immediately postpartum or in the community. There was considerable variation in mothers, particularly in parity and whether or not they had lactation insufficiency. Infants' ages at commencement of the studies ranged from newborn to 6 months. The overall certainty of evidence was low to very low because of high risk of biases (mainly due to lack of blinding), substantial clinical and statistical heterogeneity, and imprecision of measurements. Pharmacological galactagogues Nine studies compared a pharmacological galactagogue (domperidone, metoclopramide, sulpiride, thyrotropin-releasing hormone) with placebo or no treatment. The primary outcome of proportion of mothers who continued breastfeeding at 3, 4 and 6 months was not reported. Only one study (metoclopramide) reported on the outcome of infant weight, finding little or no difference (mean difference (MD) 23.0 grams, 95% confidence interval (CI) -47.71 to 93.71; 1 study, 20 participants; low-certainty evidence). Three studies (metoclopramide, domperidone, sulpiride) reported on milk volume, finding pharmacological galactagogues may increase milk volume (MD 63.82 mL, 95% CI 25.91 to 101.72; I² = 34%; 3 studies, 151 participants; low-certainty evidence). Subgroup analysis indicates there may be increased milk volume with each drug, but with varying CIs. There was limited reporting of adverse effects, none of which could be meta-analysed. Where reported, they were limited to minor complaints, such as tiredness, nausea, headache and dry mouth (very low-certainty evidence). No adverse effects were reported for infants. Natural galactagogues Twenty-seven studies compared natural oral galactagogues (banana flower, fennel, fenugreek, ginger, ixbut, levant cotton, moringa, palm dates, pork knuckle, shatavari, silymarin, torbangun leaves or other natural mixtures) with placebo or no treatment. One study (Mother's Milk Tea) reported breastfeeding rates at six months with a concluding statement of "no significant difference" (no data and no measure of significance provided, 60 participants, very low-certainty evidence). Three studies (fennel, fenugreek, moringa, mixed botanical tea) reported infant weight but could not be meta-analysed due to substantial clinical and statistical heterogeneity (I2 = 60%, 275 participants, very low-certainty evidence). Subgroup analysis shows we are very uncertain whether fennel or fenugreek improves infant weight, whereas moringa and mixed botanical tea may increase infant weight compared to placebo. Thirteen studies (Bu Xue Sheng Ru, Chanbao, Cui Ru, banana flower, fenugreek, ginger, moringa, fenugreek, ginger and turmeric mix, ixbut, mixed botanical tea, Sheng Ru He Ji, silymarin, Xian Tong Ru, palm dates; 962 participants) reported on milk volume, but meta-analysis was not possible due to substantial heterogeneity (I2 = 99%). The subgroup analysis for each intervention suggested either benefit or little or no difference (very low-certainty evidence). There was limited reporting of adverse effects, none of which could be meta-analysed. Where reported, they were limited to minor complaints such as mothers with urine that smelled like maple syrup and urticaria in infants (very low-certainty evidence). Galactagogue versus galactagogue Eight studies (Chanbao; Bue Xue Sheng Ru, domperidone, moringa, fenugreek, palm dates, torbangun, moloco, Mu Er Wu You, Kun Yuan Tong Ru) compared one oral galactagogue with another. We were unable to perform meta-analysis because there was only one small study for each match-up, so we do not know if one galactagogue is better than another for any outcome.

    AUTHORS' CONCLUSIONS: Due to extremely limited, very low certainty evidence, we do not know whether galactagogues have any effect on proportion of mothers who continued breastfeeding at 3, 4 and 6 months. There is low-certainty evidence that pharmacological galactagogues may increase milk volume. There is some evidence from subgroup analyses that natural galactagogues may benefit infant weight and milk volume in mothers with healthy, term infants, but due to substantial heterogeneity of the studies, imprecision of measurements and incomplete reporting, we are very uncertain about the magnitude of the effect. We are also uncertain if one galactagogue performs better than another. With limited data on adverse effects, we are uncertain if there are any concerning adverse effects with any particular galactagogue; those reported were minor complaints. High-quality RCTs on the efficacy and safety of galactagogues are urgently needed. A set of core outcomes to standardise infant weight and milk volume measurement is also needed, as well as a strong basis for the dose and dosage form used.

  12. Lai NM, Tan ML, Quah SY, Tan EL, Foong KW
    Singapore Med J, 2010 Sep;51(9):724-9.
    PMID: 20938614
    We conducted a retrospective audit on the inpatient assessment and care of children admitted with febrile convulsion to Hospital Batu Pahat, a district hospital in Malaysia, using the Malaysian national clinical practice guidelines and the American Academy of Paediatrics practice parameters on febrile convulsion as the reference standards.
  13. Tay YL, Amanah A, Adenan MI, Wahab HA, Tan ML
    Sci Rep, 2019 12 24;9(1):19757.
    PMID: 31874991 DOI: 10.1038/s41598-019-56106-6
    Mitragyna speciosa Korth (M. speciosa) has been widely used as a recreational product, however, there are growing concerns on the abuse potentials and toxicity of the plant. Several poisoning and fatal cases involving kratom and mitragynine have been reported but the underlying causes remain unclear. The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit underlying cardiac rapidly delayed rectifier potassium current (IKr). Pharmacological blockade of the IKr can cause acquired long QT syndrome, leading to lethal cardiac arrhythmias. This study aims to elucidate the mechanisms of mitragynine-induced inhibition on hERG1a/1b current. Electrophysiology experiments were carried out using Port-a-Patch system. Quantitative RT-PCR, Western blot analysis, immunofluorescence and co-immunoprecipitation methods were used to determine the effects of mitragynine on hERG1a/1b expression and hERG1-cytosolic chaperones interaction. Mitragynine was found to inhibit the IKr current with an IC50 value of 332.70 nM. It causes a significant reduction of the fully-glycosylated (fg) hERG1a protein expression but upregulates both core-glycosylated (cg) expression and hERG1a-Hsp90 complexes, suggesting possible impaired hERG1a trafficking. In conclusion, mitragynine inhibits hERG1a/1b current through direct channel blockade at lower concentration, but at higher concentration, it upregulates the complexation of hERG1a-Hsp90 which may be inhibitory towards channel trafficking.
  14. Tan ML, Parkinson EK, Yap LF, Paterson IC
    Sci Rep, 2021 01 12;11(1):584.
    PMID: 33436723 DOI: 10.1038/s41598-020-79789-8
    Many of the characteristics ascribed to cancer-associated fibroblasts (CAFs) are shared by activated, autophagic and senescent fibroblasts. Whilst most oral squamous cell carcinomas (OSCCs) are genetically unstable (GU-OSCC), genetically stable variants (GS-OSCC) have been described and, notably, CAF activation (myofibroblast differentiation) and senescence are characteristics particularly associated with GU-OSCCs. However, it is not known whether autophagy is disrupted in these cells or whether autophagy regulates the development of the myofibroblast and senescent phenotypes. In this study, we show that senescent CAFs from GU-OSCCs contained more autophagosomes than normal human oral fibroblasts (NHOFs) and CAFs from GS-OSCCs possibly due to autophagic impairment. Further, we show that deregulation of autophagy in normal fibroblasts, either by inhibition with autophagy inhibitor, SAR405, or activation with TGF-β1, induced fibroblast activation and senescence: In response to TGF-β1, autophagy was induced prior to the development of the activated and senescent phenotypes. Lastly, we show that both SAR405- and TGF-β1-treated NHOFs enhance OSCC cell migration but only TGF-β1-treated cells increase OSCC invasion through Matrigel, indicating that TGF-β1 has additional effects that are independent of fibroblast activation/senescence. These results suggest a functional role for autophagy in the development of myofibroblast and CAF phenotypes.
  15. Halder B, Ahmadianfar I, Heddam S, Mussa ZH, Goliatt L, Tan ML, et al.
    Sci Rep, 2023 May 17;13(1):7968.
    PMID: 37198391 DOI: 10.1038/s41598-023-34774-9
    Climatic condition is triggering human health emergencies and earth's surface changes. Anthropogenic activities, such as built-up expansion, transportation development, industrial works, and some extreme phases, are the main reason for climate change and global warming. Air pollutants are increased gradually due to anthropogenic activities and triggering the earth's health. Nitrogen Dioxide (NO2), Carbon Monoxide (CO), and Aerosol Optical Depth (AOD) are truthfully important for air quality measurement because those air pollutants are more harmful to the environment and human's health. Earth observational Sentinel-5P is applied for monitoring the air pollutant and chemical conditions in the atmosphere from 2018 to 2021. The cloud computing-based Google Earth Engine (GEE) platform is applied for monitoring those air pollutants and chemical components in the atmosphere. The NO2 variation indicates high during the time because of the anthropogenic activities. Carbon Monoxide (CO) is also located high between two 1-month different maps. The 2020 and 2021 results indicate AQI change is high where 2018 and 2019 indicates low AQI throughout the year. The Kolkata have seven AQI monitoring station where high nitrogen dioxide recorded 102 (2018), 48 (2019), 26 (2020) and 98 (2021), where Delhi AQI stations recorded 99 (2018), 49 (2019), 37 (2020), and 107 (2021). Delhi, Kolkata, Mumbai, Pune, and Chennai recorded huge fluctuations of air pollutants during the study periods, where ~ 50-60% NO2 was recorded as high in the recent time. The AOD was noticed high in Uttar Pradesh in 2020. These results indicate that air pollutant investigation is much necessary for future planning and management otherwise; our planet earth is mostly affected by the anthropogenic and climatic conditions where maybe life does not exist.
  16. Yeap JW, Ali IAH, Ibrahim B, Tan ML
    Pulm Pharmacol Ther, 2023 Aug;81:102218.
    PMID: 37201652 DOI: 10.1016/j.pupt.2023.102218
    COPD pathogenesis is frequently associated with endoplasmic reticulum stress (ER stress) progression. Targeting the major unfolded protein response (UPR) branches in the ER stress pathway may provide pharmacotherapeutic selection strategies for treating COPD and enable relief from its symptoms. In this study, we aimed to systematically review the potential role of the ER stress inhibitors of major UPR branches (IRE1, PERK, and ATF6) in COPD-related studies and determine the current stage of knowledge in this field. The systematic review was carried out adhering to the PRISMA checklist based on published studies obtained from specific keyword searches of three databases, namely PubMed, ScienceDirect and Springer Database. The search was limited to the year 2000-2022 which includes all in vitro studies, in vivo studies and clinical trials related to the application of ER stress inhibitors toward COPD-induced models and disease. The risk of bias was evaluated using the QUIN, SYRCLE, revised Cochrane risk of bias tool for randomized trials (RoB 2.0) and NIH tool respectively. A total of 7828 articles were screened from three databases and a final total of 37 studies were included in the review. The ER stress and UPR pathways are potentially useful to prevent COPD progression and attenuate the exacerbation of COPD and related symptoms. Interestingly, the off-target effects from inhibition of the UPR pathway may be desirable or undesirable depending on context and therapeutic applications. Targeting the UPR pathway could have complex consequences as the production of ER molecules involved in folding may be impaired which could continuously provoke misfolding of proteins. Although several emerging compounds were noted to be potentially useful for targeted therapy against COPD, clinical studies have yet to be thoroughly explored.
  17. Lu J, Wei H, Wu J, Jamil MF, Tan ML, Adenan MI, et al.
    PLoS One, 2014;9(12):e115648.
    PMID: 25535742 DOI: 10.1371/journal.pone.0115648
    INTRODUCTION: Mitragynine is a major bioactive compound of Kratom, which is derived from the leave extracts of Mitragyna speciosa Korth or Mitragyna speciosa (M. speciosa), a medicinal plant from South East Asia used legally in many countries as stimulant with opioid-like effects for the treatment of chronic pain and opioid-withdrawal symptoms. Fatal incidents with Mitragynine have been associated with cardiac arrest. In this study, we determined the cardiotoxicity of Mitragynine and other chemical constituents isolated using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

    METHODS AND RESULTS: The rapid delayed rectifier potassium current (IKr), L-type Ca2+ current (ICa,L) and action potential duration (APD) were measured by whole cell patch-clamp. The expression of KCNH2 and cytotoxicity was determined by real-time PCR and Caspase activity measurements. After significant IKr suppression by Mitragynine (10 µM) was confirmed in hERG-HEK cells, we systematically examined the effects of Mitragynine and other chemical constituents in hiPSC-CMs. Mitragynine, Paynantheine, Speciogynine and Speciociliatine, dosage-dependently (0.1∼100 µM) suppressed IKr in hiPSC-CMs by 67%∼84% with IC50 ranged from 0.91 to 2.47 µM. Moreover, Mitragynine (10 µM) significantly prolonged APD at 50 and 90% repolarization (APD50 and APD90) (439.0±11.6 vs. 585.2±45.5 ms and 536.0±22.6 vs. 705.9±46.1 ms, respectively) and induced arrhythmia, without altering the L-type Ca2+ current. Neither the expression, and intracellular distribution of KCNH2/Kv11.1, nor the Caspase 3 activity were significantly affected by Mitragynine.

    CONCLUSIONS: Our study indicates that Mitragynine and its analogues may potentiate Torsade de Pointes through inhibition of IKr in human cardiomyocytes.

  18. Hariono M, Choi SB, Roslim RF, Nawi MS, Tan ML, Kamarulzaman EE, et al.
    PLoS One, 2019;14(1):e0210869.
    PMID: 30677071 DOI: 10.1371/journal.pone.0210869
    Dengue virus Type 2 (DENV-2) is predominant serotype causing major dengue epidemics. There are a number of studies carried out to find its effective antiviral, however to date, there is still no molecule either from peptide or small molecules released as a drug. The present study aims to identify small molecules inhibitor from National Cancer Institute database through virtual screening. One of the hits, D0713 (IC50 = 62 μM) bearing thioguanine scaffold was derivatised into 21 compounds and evaluated for DENV-2 NS2B/NS3 protease inhibitory activity. Compounds 18 and 21 demonstrated the most potent activity with IC50 of 0.38 μM and 16 μM, respectively. Molecular dynamics and MM/PBSA free energy of binding calculation were conducted to study the interaction mechanism of these compounds with the protease. The free energy of binding of 18 calculated by MM/PBSA is -16.10 kcal/mol compared to the known inhibitor, panduratin A (-11.27 kcal/mol), which corroborates well with the experimental observation. Results from molecular dynamics simulations also showed that both 18 and 21 bind in the active site and stabilised by the formation of hydrogen bonds with Asn174.
  19. Woon FC, Chin YS, Ismail IH, Batterham M, Abdul Latiff AH, Gan WY, et al.
    PLoS One, 2019;14(6):e0216439.
    PMID: 31233513 DOI: 10.1371/journal.pone.0216439
    BACKGROUND: Despite perennial sunshine, vitamin D deficiency is prevalent among Malaysians especially pregnant women. This study determines the vitamin D status and its associated factors among third trimester pregnant women attending government health clinics in Selangor and Kuala Lumpur, Malaysia.

    METHODS: Information on socio-demographic characteristics, obstetrical history, and sun exposure were obtained through face-to-face interviews. Vitamin D intake was assessed using a semi-quantitative food frequency questionnaire (FFQ). Serum 25-hydroxyvitamin D concentration was measured and classified as deficient (< 30 nmol/L), insufficient (30-50 nmol/L), and sufficient (≥ 50 nmol/L).

    RESULTS: Of the 535 pregnant women recruited, 42.6% were vitamin D deficient. They consumed an average of 8.7 ± 6.7 μg of vitamin D daily. A total of 80.4% of the vitamin D were obtained from the food sources, while 19.6% were from dietary supplements. Fish and fish products showed the highest contribution to vitamin D intake (35.8%). The multivariable generalized linear mixed models, with clinic as a random effect, indicates that higher intake of vitamin D is associated with lower odds of vitamin D deficiency among pregnant women (OR = 0.96; 95% CI = 0.93-0.99). The odds of having vitamin D deficiency was reduced by 87% in non-Malays (OR = 0.14; 95% CI = 0.05-0.41) compared to Malays. No associations were found between age, educational level, monthly household income, work status, gravidity, parity, pre-pregnancy body mass index, total hours of sun exposure, total percentage of body surface area, and sun exposure index per day with vitamin D deficiency.

    CONCLUSION: Vitamin D deficiency is prevalent among Malaysian pregnant women. Considering the possible adverse obstetric and fetal outcomes of vitamin D deficiency during pregnancy, future nutrition education should emphasise on vitamin D-fortified foods consumption among pregnant women by taking into consideration ethnic differences.
  20. Kabir MH, Nur-E-Alam SM, Datta A, Tan ML, Rahman MS
    PLoS One, 2023;18(9):e0292254.
    PMID: 37773932 DOI: 10.1371/journal.pone.0292254
    The use of pheromone traps can minimize the excess application of synthetic insecticides, while can also benefit the environment. The use of pheromone traps has been promoted and suggested to vegetable farmers of Bangladesh for widespread adoption. However, the majority of farmers have continued to spray insecticides instead of using pheromone traps. The present study investigated the factors influencing farmers' adoption, dis-adoption, and non-adoption behavior of pheromone traps for managing insect pests. Primary data were collected from 438 vegetable growers. Data were analyzed using descriptive statistics and multinomial logistic regression. About 27% of the farmers abandoned the technique shortly after it was adopted as it was time-consuming to manage insect pests. Marginal effect analysis revealed that the likelihood of continued adoption was 34.6% higher for farmers who perceived that pheromone traps were useful in controlling insect pests. In contrast, the likelihood of dis-adoption was 16.5% and 10.4% higher for farmers who maintained communication with private pesticide company agents and neighbor farmers, respectively. Extension services by government extension personnel might be encouraged and maintained as a key component in increasing farmer awareness regarding the use of pheromone trap. Strategies to promote pheromone traps in vegetable production should highlight the positive impacts to farmers and the environment, as this would most likely lead to their continued and widespread use after initial adoption.
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