MyMedR

Treatment of congenital chylothorax with octreotide in a hydropic preterm infant

Choo YM, Lim CT

Paediatr Int Child Health, 2013 May;33(2):116-9.

PMID: 23925288 DOI: 10.1179/2046905512Y.0000000030

Congenital chylothorax is rare in preterm infants. While most cases respond to conservative treatment, a few require surgery. Treatment with intravenous octreotide has been reported to have varying success in preterm infants. A fetus was diagnosed with bilateral hydrothoraces at 29 weeks of gestation and repeated thoracocentesis was performed antenatally to allow growth of the lungs. She was delivered electively at 32 weeks by caesarean section. Hydrops fetalis was confirmed and chest tubes were inserted bilaterally soon after birth. Intravenous octreotide was commenced on day 4 of life, titrated to a maximum of 10 μg/kg/hr for a total of 28 days. Hydrothorax resolved at day 30 and total parenteral nutrition was given for a total of 37 days. She was successfully extubated on day 40 of life and discharged on day 80. On review at 6 months of age, she was thriving and developing normally.

Bisindole alkaloids

Kam TS, Choo YM

Alkaloids Chem Biol, 2006;63:181-337.

PMID: 17133716

Fulltext Improved Method for the Qualitative Analyses of Palm Oil Carotenes Using UPLC

Ng MH, Choo YM

J Chromatogr Sci, 2016 Apr;54(4):633-8.

PMID: 26941414 DOI: 10.1093/chromsci/bmv241

Palm oil is the richest source of natural carotenes, comprising 500-700 ppm in crude palm oil (CPO). Its concentration is found to be much higher in oil extracted from palm-pressed fiber, a by-product from the milling of oil palm fruits. There are 11 types of carotenes in palm oil, excluding the cis/trans isomers of some of the carotenes. Qualitative separation of these individual carotenes is particularly useful for the identification and confirmation of different types of oil as the carotenes profile is unique to each type of vegetable oil. Previous studies on HPLC separation of the individual palm carotenes reported a total analyses time of up to 100 min using C30 stationary phase. In this study, the separation was completed in <5 min. The qualitative separation was successfully carried out using a commonly used stationary phase, C18.

Venalstonine and dioxokopsan derivatives from Kopsia fruticosa

Kam TS, Choo YM

Phytochemistry, 2004 Jul;65(14):2119-22.

PMID: 15279982

Two new venalstonine derivatives, viz., venacarpines A and B, and one new dioxokopsan derivative, kopsorinine, in addition to the kopsifolines A-F, and 11 other known alkaloids, were isolated from a Malayan Kopsia species. The structures of the new alkaloids were determined using NMR and MS analysis.

New indole alkaloids from Alstonia macrophylla

Kam TS, Choo YM

J Nat Prod, 2004 Apr;67(4):547-52.

PMID: 15104482

Ten new indole alkaloids, alstomaline (1), 10,11-dimethoxynareline (2), alstohentine (3), alstomicine (4), 16-hydroxyalstonisine (5), 16-hydroxyalstonal (6), 16-hydroxy-N(4)-demethylalstophyllal oxindole (7), alstophyllal (8), 6-oxoalstophylline (9), and 6-oxoalstophyllal (10), in addition to 21 other known ones, were obtained from the leaf extract of the Malayan Alstonia macrophylla. The structures were determined using NMR and MS analysis.

Alkaloids from Alstonia angustifolia

Kam TS, Choo YM

Phytochemistry, 2004 Mar;65(5):603-8.

PMID: 15003424

Six new alkaloids, viz., alstolactone, affinisine oxindole, lagumicine, N(4)-demethylalstonerine, N(4)-demethylalstonerinal, and 10-methoxycathafoline N(4)-oxide, in addition to 36 other known alkaloids, were obtained from the leaf extract of Alstonia angustifolia var. latifolia. The structures of the new alkaloids were determined using NMR and MS analysis.

Fulltext Acute ptosis as a presentation of preseptal cellulitis leading to cerebral abscess in a patient with uncontrolled diabetes

Razali NR, Choo YM

Malays Fam Physician, 2021 Mar 25;16(1):136-138.

PMID: 33948155 DOI: 10.51866/cr1010

Acute ptosis due to preseptal cellulitis requires urgent medical attention, as the infection can extend posteriorly into the orbit, leading to significant visual and cerebral complications. We report a case of a 58-year-old woman with uncontrolled diabetes mellitus presenting with acute ptosis due to preseptal cellulitis. After initial resolution of fever with intravenous amoxicillin-clavulanate, she experienced a seizure due to cerebral abscess a week later and was treated with intravenous ceftriaxone. Preseptal cellulitis is usually treated on an outpatient basis with oral antibiotics, as it rarely extends posteriorly to cause cerebral complications. We wish to highlight the importance of admitting patients with preseptal cellulitis in patients with uncontrolled diabetes for intravenous antibiotics due to the potential for visual and cerebral complications.

A new flavone from Malaysia Borneo Marsdenia tinctoria

Mohd Nasuha NA, Choo YM

Nat Prod Res, 2016 Jul;30(13):1532-6.

PMID: 26618710 DOI: 10.1080/14786419.2015.1118629

Marsdenia tinctoria is an indigo producing plant commonly found in Borneo, Malaysia. In this present study, one new flavone kapitone (1) and three known compounds, that is 3,2'-dihydroxyflavone (2), 1-methylcyclobutene (3) and dimethyl isatoate (4) were isolated from the Malaysia Borneo M. tinctoria R. Br. (Apocynaceae). These compounds were isolated and characterised using extensive chromatographic and spectroscopic methods.

Baby cry recognition based on WOA-VMD and an improved Dempster-Shafer evidence theory

Zhang K, Ting HN, Choo YM

Comput Methods Programs Biomed, 2024 Mar;245:108043.

PMID: 38306944 DOI: 10.1016/j.cmpb.2024.108043

BACKGROUND AND OBJECTIVE: Conflict may happen when more than one classifier is used to perform prediction or classification. The recognition model error leads to conflicting evidence. These conflicts can cause decision errors in a baby cry recognition and further decrease its recognition accuracy. Thus, the objective of this study is to propose a method that can effectively minimize the conflict among deep learning models and improve the accuracy of baby cry recognition.

METHODS: An improved Dempster-Shafer evidence theory (DST) based on Wasserstein distance and Deng entropy was proposed to reduce the conflicts among the results by combining the credibility degree between evidence and the uncertainty degree of evidence. To validate the effectiveness of the proposed method, examples were analyzed, and applied in a baby cry recognition. The Whale optimization algorithm-Variational mode decomposition (WOA-VMD) was used to optimally decompose the baby cry signals. The deep features of decomposed components were extracted using the VGG16 model. Long Short-Term Memory (LSTM) models were used to classify baby cry signals. An improved DST decision method was used to obtain the decision fusion.

RESULTS: The proposed fusion method achieves an accuracy of 90.15% in classifying three types of baby cry. Improvement between 2.90% and 4.98% was obtained over the existing DST fusion methods. Recognition accuracy was improved by between 5.79% and 11.53% when compared to the latest methods used in baby cry recognition.

CONCLUSION: The proposed method optimally decomposes baby cry signal, effectively reduces the conflict among the results of deep learning models and improves the accuracy of baby cry recognition.

Very long chain fatty acid methyl esters in transesterified palm oil

Puah CW, Choo YM, Ma AN, Chuah CH

Lipids, 2006 Mar;41(3):305-8.

PMID: 16711607

Some unidentified minor compounds have been observed in the residue from short-path distillation of transesterified palm oil that are not detected in the original palm oil. A method combining short-path distillation to enrich the unknowns with fractionation using solid-phase extraction is described. The fractionated components were identified using GC coupled with MS. The transesterified palm oil was found to contain methyl esters of up to C32 carbon atoms. In the very long chain FAME with carbon numbers > or = 20, both even and odd carbon numbers accounted for 0.26 wt%, with C24 and C26 being the major ones present in the residue after short-path distillation of transesterified palm oil.

Fulltext Super, red palm and palm oleins improve the blood pressure, heart size, aortic media thickness and lipid profile in spontaneously hypertensive rats

Boon CM, Ng MH, Choo YM, Mok SL

PLoS One, 2013;8(2):e55908.

PMID: 23409085 DOI: 10.1371/journal.pone.0055908

Oleic acid has been shown to lower high blood pressure and provide cardiovascular protection. Curiosity arises as to whether super olein (SO), red palm olein (RPO) and palm olein (PO), which have high oleic acid content, are able to prevent the development of hypertension.

A new oxolane from Enterobacter cloacae

Yap AC, Chan KG, Sim KS, Choo YM

Nat Prod Res, 2016 Apr;30(7):783-8.

PMID: 26252083 DOI: 10.1080/14786419.2015.1065492

Enterobacter cloacae is a highly pathogenic Gram-negative proteobacterium which is responsible for a wide array of infections. In the present study, the fermentation culture of E. cloacae has yielded one new oxolane compound, Rimboxo (1) in addition to three known compounds, i.e. Maculosine (2), phenylacetic acid (3) and methyl myristate (4). These compounds were isolated and characterised using extensive chromatographic and spectroscopic methods, and were subjected to cytotoxicity evaluations.

Cardiac tamponade from peripherally-inserted central venous catheters in neonates: Three case reports

Khoo WV, Choo YM, Zahari N, Kamar AA

Med J Malaysia, 2021 07;76(4):566-568.

PMID: 34305120

Pericardial effusion (PCE) and cardiac tamponade (CT) are rare but life-threatening complications of percutaneouslyinserted central catheter (PICC) use in neonates. There is often a lack in index of suspicion in a neonate with sudden deterioration, resulting in high mortality. We describe a series of three cases of PICC-related PCE/CT in low birth weight infants whose timely diagnosis with echocardiography and pericardiocentesis led to successful resuscitation and survival. We suggest that echocardiographic skills to determine tip position and pericardiocentesis be taught in neonatal resuscitation programs to ensure good outcomes of this otherwise fatal complication.

Efficiency of Hollow Fiber Liquid-Phase Microextraction Chromatography Methods in the Separation of Organic Compounds: A Review

Alsharif AM, Tan GH, Choo YM, Lawal A

J Chromatogr Sci, 2017 03 01;55(3):378-391.

PMID: 27903555 DOI: 10.1093/chromsci/bmw188

Hollow fiber liquid-phase microextraction (HF-LPME) techniques coupled to chromatographic systems have been widely used for extraction and determination of diverse compounds. HF-LPME was able to provide better results in precision, accuracy, selectivity and enrichment factor, in addition to reduction of matrix effect and carry over. It is applicable within a wide pH range and compatible with most analytical instruments which enable the utilization of HF-LPME in a wide variety of applications. This review focused on the modified HF-LPME techniques, efficiency, comparison to other LPME methods and applications.

Fulltext Management of neonatal jaundice in primary care

Wan A, Mat Daud S, Teh SH, Choo YM, Kutty FM

Malays Fam Physician, 2016;11(2-3):16-19.

PMID: 28461853

The Clinical Practice Guidelines on Management of Neonatal Jaundice 2003 was updated by a multidisciplinary development group and approved by the Ministry of Health Malaysia in 2014. A systematic review of 13 clinical questions was conducted using evidence retrieved mainly from Medline and Cochrane databases. Critical appraisal was done using the Critical Appraisal Skills Programme checklist. Recommendations were formulated based on the accepted 103 evidences and tailored to local setting as stated below. Neonatal jaundice (NNJ) is a common condition seen in primary care. Multiple risk factors contribute to severe NNJ, which if untreated can lead to adverse neurological outcomes. Visual assessment, transcutaneous bilirubinometer (TcB) and total serum bilirubin (TSB) are the methods used for the detection of NNJ. Phototherapy remains the mainstay of the treatment. Babies with severe NNJ should be followed-up to detect and manage sequelae. Strategies to prevent severe NNJ include health education, identification of risk factors, proper assessment and early referral.

Fulltext sn-2 Hypothesis: a Review of the Effects of Palm Oil on Blood Lipid Levels

Sin Teh S, Ong ASH, Choo YM, Mah SH

J Oleo Sci, 2018;67(6):697-706.

PMID: 29863090 DOI: 10.5650/jos.ess18009

Saturated fats are commonly claimed to raise human blood cholesterols and contribute to cardiovascular disease. Previous literature data were highlighted that although palm oil is 50% saturated, it does not behave like a saturated fat. Human trials were conducted to compare the effects on serum cholesterol levels given by palm olein and monounsaturated oils. It was postulated that saturation/unsaturation of the fatty acids situated at sn-2 positions of triglycerides in the fat molecules determine the induced blood lipid levels but not the overall saturation of oils. The results showed that the lipid parameters (LDL and HDL) effects induced by these oils are similar with no significant differences. This study provides concrete evidence that the unsaturation levels of these oils at sn-2 position of TG are similar (90-100%) which are claimed to be responsible for the lipid parameters. In conclusion, the public negative perception on believing that the overall saturation of oils is detrimental to health should be corrected because in fact the unsaturation at sn-2 positions of the saturated vegetable fat such as palm olein and cocoa butter make them behave like mono-unsaturated oils, unlike saturated animal fats that possess a high content of saturated fatty acids at sn-2 position.

Biologically active ibogan and vallesamine derivatives from Tabernaemontana divaricata

Kam TS, Pang HS, Choo YM, Komiyama K

Chem Biodivers, 2004 Apr;1(4):646-56.

PMID: 17191876

Six new indole alkaloids, viz., (3S)-3-cyanocoronaridine (2), (3S)-3-cyanoisovoacangine (3), conolobine A (5), conolobine B (6), conolidine (7), and (3R/3S)-3-ethoxyvoacangine (8), in addition to 36 known ones, were obtained from the stem-bark extract of the Malayan Tabernaemontana divaricata. The structures were determined by NMR and MS analysis. The CN-substituted alkaloids showed appreciable cytotoxicity towards the KB human oral epidermoid carcinoma cell-line.

Fulltext Ultrasound-assisted encapsulation of Pandan (Pandanus amaryllifolius) extract

Omer N, Choo YM, Ahmad N, Mohd Yusof NS

Ultrason Sonochem, 2021 Nov;79:105793.

PMID: 34673338 DOI: 10.1016/j.ultsonch.2021.105793

Pandan (Pandanus amaryllifolius) is commonly used as a food ingredient in Southeast Asia due to its delicious flavor, appetizing aroma and bright green colour. Pandan plant is uniquely found only in certain parts of the world. Despite its increasing popularity worldwide, its export market is limited by practical issues. One of the main problems for exporting Pandan to global market is its stability during transport. Due to the volatility of its active constituent, the functional properties of Pandan are lost during storage and shipment. In this study, we explored the ability of ultrasound processing technology to encapsulate the aromatic Pandan extract using lysozyme or chitosan as a shell material. 20 kHz ultrasonicator was used to encapsulate the pandan extract at 150 W of applied power. Two parameters, the ultrasonic probe tip and the core-to-shell ratio were varied to control the properties of the encapsulates. The diameters of the probe tip used were 0.3 and 1.0 cm. The core-to-shell volume ratios used were 1:160 and 1:40. The size distribution and the stability of the synthesized microspheres were characterized to understand and explore the possible parameters variation impact. Both size and size distribution of the microspheres were found to be influenced by the parameters varied to certain extent. The results showed that the mean size of the microspheres was generally smallest when using 1 cm probe tip with lower core-to-shell volume ratio but largest when using the 3 mm tip with higher core-to-shell volume ratio. This indicates that the sonication parameters could be fine-tuned to achieve the encapsulation of Pandan extract for storage and export. The pandan-encapsulated microspheres were also found to be stable during storage at least for one month.

Glabraquinone A and B, new bisanthraquinones from Prismatomeris glabra (Korth.) Valeton

Primus PS, Wu CH, Kao CL, Choo YM

Nat Prod Res, 2024 Apr;38(8):1406-1413.

PMID: 36416441 DOI: 10.1080/14786419.2022.2147932

Two new bisanthraquinones, glabraquinone A and B (1-2) were isolated from the root of Prismatomeris glabra (Korth.) Valeton. In addition to the new glabraquinones, six known anthraquinones, that is, 1-hydroxy-2-methoxy-6-methylanthraquinone (3), 1,2-dimethoxy-7-methylanthraquinone (4), lucidin (5), nordamnacanthal (6), damnacanthal (7) and 2-carboxaldehyde-3-hydroxyanthraquinone (8)) and an aromatic compound, that is, catechol diethyl ether (9) were isolated and characterized in this study. Compounds 1, 4 and 9 showed mild activity, reducing N2A cell viability to 77%, 82% and 77%, respectively, in anti-neuroblastoma assay.

Harnessing Natural Resources for Advancements in Dengue Virus Treatment

Amin Hapis NAN, Nor Rashid N, Choo YM

Curr Top Med Chem, 2024 Aug 27.

PMID: 39253916 DOI: 10.2174/0115680266312717240821062535

Dengue fever, caused by the Dengue virus (DENV) and transmitted by Aedes aegypti mosquitoes, has become endemic in over 100 countries. Despite considerable research, there is a lack of specific drugs for clinical use against dengue. Hence, further exploration to identify anti-- dengue compounds is essential. In recent years, natural products have gained attention for their antiviral properties. Plant-based medicines are particularly appealing due to their safety and low toxicity. This review summarizes natural compounds with potential antiviral activity against DENV, highlighting their mechanisms of action. Various compounds, from traditional herbal remedies to novel plant isolates, show promise against dengue, targeting crucial viral proteins like the envelope protein, proteases, and RNA polymerase. Exploring natural sources of antiviral agents against dengue is crucial. These compounds offer hope for effective treatments and mitigating dengue's global impact.

Displaying publications 1 - 20 of 68 in total