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The association between physical activity and burnout among anaesthesia postgraduate trainees in Malaysia

Jaishree S, Chong KW, Lim TA

Med J Malaysia, 2022 Nov;77(6):655-660.
PMID: 36448381

INTRODUCTION: Burnout is a psychological problem which is becoming more prevalent among medical professionals resulting in various negative outcomes. Physical activity has been found to be an effective method in alleviating burnout. The aim of this study was to determine the association between physical activity and burnout among postgraduate anaesthesia trainees in Malaysia. The study also intended to determine the level of physical activity among trainees, the factors affecting this practice, and the prevalence of burnout among anaesthesia trainees.
MATERIALS AND METHODS: An online self-administered questionnaire was sent out to all postgraduate anaesthesia trainees between August 2020 and January 2021 via email and respondents were recruited on a voluntary basis.
RESULTS: The prevalence of burnout among postgraduate anaesthesia trainees was high (54%). This prevalence was higher among trainees with low a level of physical activity. Half of the trainees (50.8%) engaged in moderate physical activity while only 12% reported a high level of physical activity. The postgraduate study year was found to be a significant factor affecting the practice of physical activity.
CONCLUSION: There is a significant association between physical activity and burnout among postgraduate anaesthesia trainees in Malaysia. Physical activity has the potential to be an essential method of reducing burnout. Hence, measures should be implemented to improve the practice of physical activity among healthcare professionals in order to reduce workplace burnout.
Simple two-portal technique for endoscopic gastrocnemius recession: clinical tip

Yeap EJ, Shamsul SA, Chong KW, Sands AK

Foot Ankle Int, 2011 Aug;32(8):830-3.
PMID: 22049872
Radiofrequency coblation for chronic foot and ankle tendinosis

Yeap EJ, Chong KW, Yeo W, Rikhraj IS

J Orthop Surg (Hong Kong), 2009 Dec;17(3):325-30.
PMID: 20065374

To evaluate outcomes of radiofrequency coblation for chronic tendinosis of the foot and ankle tendons.
Reactions of Anodically Generated Methoxystilbene Cation Radicals: The Influence of Ortho-Substituted Vinyl and Formyl Groups

Chong KW, Thomas NF, Low YY, Kam TS

J Org Chem, 2019 Jun 07;84(11):7279-7290.
PMID: 31056921 DOI: 10.1021/acs.joc.9b00939

The present investigation represents a continuation of studies on the effect of ortho'-substitution on the reactivity of anodically generated methoxystilbene cation radicals. Whereas previous studies have focused on the effect of ortho'-substituted nucleophilic groups such as OH, NH2, CH2OH, CH2NH2, and COOH, the present study extends the investigation to ortho'-substituted vinyl and formyl groups. The results show that when the ortho'-substituent is a vinyl group, the products include a bisdihydronaphthalene derivative and a doubly bridged, dibenzofused cyclononane from direct trapping of a bis carbocation intermediate. In the presence of an additional 3-methoxy substituent, the products are the tetracyclic chrysene derivatives. When the ortho'-substituent is a nonnucleophilic formyl group, the products include fused indanylnaphthalenes and indanylbenzopyran aldehydes. When an additional 3-methoxy group is present, an unusual fused benzofluorene-dibenzoannulene product is obtained. Mechanistic rationalization for the formation of the various products is presented. The results have contributed to a deeper understanding of how the reactivity of the methoxystilbene cation radicals is affected by the nature of the ortho'-substituents.
Reactivity of Anodically Generated 4-Methoxystilbene Cation Radicals: The Influence of Ortho-Substituted Hydroxymethyl, Aminomethyl, and Carboxylic Acid Groups

Chong KW, Thomas NF, Low YY, Kam TS

J Org Chem, 2018 Dec 21;83(24):15087-15100.
PMID: 30488699 DOI: 10.1021/acs.joc.8b02360

The effect of ortho'-substituted side chains bearing nucleophilic groups such as CH2OH, CH2NHR, and CO2H on the reactivity of anodically generated 4-methoxy- and 3,4-dimethoxystilbene cation radicals was investigated, and results were compared with those of substrates where the nucleophilic groups such as OH and NHR are directly attached to the aromatic ring. It was found that when ortho'-substituted groups such as CH2OH or CH2NHR are present in the other ring, only direct intramolecular cation-nucleophile reactions occur to give bisbenzopyrans or bisisoquinolines. Crossover products (previously obtained when the ortho' substituents were OH and NH2) such as the fused benzoxepanes/fused benzoazepanes were not formed. When the ortho' substituent is COOH, direct intramolecular cation-nucleophile reaction occurs to give the corresponding bis-δ-lactones in high yield. The presence of an additional 3-methoxy substituent resulted in the formation of other fused polycyclic products due to competing aromatic substitution reactions. Reaction pathways leading to the different products and reasons for the difference in behavior shown by the present stilbenes are presented. The results have provided additional insight into the reactivity and behavior of anodically generated stilbene cation radicals.
Cytotoxic vobasine, tacaman, and corynanthe-tryptamine bisindole alkaloids from Tabernaemontana and structure revision of tronoharine

Sim DS, Chong KW, Nge CE, Low YY, Sim KS, Kam TS

J Nat Prod, 2014 Nov 26;77(11):2504-12.
PMID: 25333996 DOI: 10.1021/np500589u

Seven new indole alkaloids (1-7) comprising four vobasine, two tacaman, and one corynanthe-tryptamine bisindole alkaloid were isolated from the stem-bark extract of a Malayan Tabernaemontana. Two of the new vobasine alkaloids (1, 3), as well as 16-epivobasine (15) and 16-epivobasenal (17), showed appreciable cytotoxicity toward KB cells (IC50 ca. 5 μg/mL). The structure of the known Tabernaemontana alkaloid tronoharine (8) was revised based on newly acquired NMR data, as well as X-ray diffraction analysis.
Ibogan, Aspidosperman, Vincamine, and Bisindole Alkaloids from a Malayan Tabernaemontana corymbosa: Iboga Alkaloids with C-20α Substitution

Nge CE, Chong KW, Thomas NF, Lim SH, Low YY, Kam TS

J Nat Prod, 2016 05 27;79(5):1388-99.
PMID: 27077800 DOI: 10.1021/acs.jnatprod.6b00129

Ten new indole alkaloids (1-10) comprising five ibogan, two aspidosperman, one vincamine, and two bisindole alkaloids, in addition to 32 known alkaloids, were isolated from the stem-bark extract of a Malayan Tabernaemontana corymbosa. The structures of these alkaloids were determined based on analysis of the NMR and MS data and, in five instances (1, 3, 5, 6, 8), confirmed by X-ray diffraction analysis. Two of the iboga alkaloids, conodusines B (2) and C (3), and the iboga-containing bisindole tabernamidine B (10) are notable for the presence of an α-substituted acetyl group at C-20 of the iboga carbon skeleton. The iboga alkaloid (+)-conodusine E (5) had MS and NMR data that were identical to those of (-)-ervatamine I, recently isolated from Ervatamia hainanensis. Establishment of the absolute configuration of (+)-conodusine E (5) was based on analysis of the ECD data, correlation with (-)-heyneanine, and X-ray analysis, which showed that (+)-5 belongs to the same enantiomeric series as exemplified by (-)-coronaridine. The configuration at C-20' of the previously reported Tabernaemontana bisindole alkaloid 19'-oxotabernamine (renamed tabernamidine B) required revision based on the present results. Several of the bisindoles showed pronounced in vitro growth inhibitory activity against drug-sensitive and vincristine-resistant KB cells.
Arborisidine and Arbornamine, Two Monoterpenoid Indole Alkaloids with New Polycyclic Carbon-Nitrogen Skeletons Derived from a Common Pericine Precursor

Wong SP, Chong KW, Lim KH, Lim SH, Low YY, Kam TS

Org. Lett., 2016 Apr 1;18(7):1618-21.
PMID: 27033525 DOI: 10.1021/acs.orglett.6b00478

Two new monoterpene indole alkaloids, characterized by previously unencountered natural product skeletons, viz., arborisidine (1), incorporating indolizidine and cyclohexanone moieties fused to an indole unit, and arbornamine (2), incorporating an unprecedented 6/5/6/5/6 "arbornane" skeleton (distinct from the eburnan or tacaman skeleton), were isolated from a Malayan Kopsia arborea. The structures of the alkaloids were determined based on analysis of the NMR and MS data. Possible biogenetic pathways to these alkaloids from a common pericine precursor (3) are presented.
Perioperative anaphylaxis: A five-year review in a tertiary paediatric hospital

Toh TS, Foo SY, Loh W, Chong KW, En Goh A, Hee HI, et al.

Anaesth Intensive Care, 2021 Jan;49(1):44-51.
PMID: 33472385 DOI: 10.1177/0310057X20964470

Making a diagnosis of perioperative anaphylaxis and identifying culprit drugs are diagnostic challenges. The aim of this study is to describe the perioperative presentation of anaphylaxis and results of patients who underwent allergy evaluation. This is a retrospective review of perioperative anaphylaxis of severity Grade 2 and above based on the Australian and New Zealand Anaesthetic Allergy Group criteria from 2015 to 2019 in a tertiary paediatric hospital. Data collected were demographics, clinical features, investigations and management. Of the 35,361 cases of paediatric anaesthesia, there were 15 cases of perioperative anaphylaxis, giving an incidence of four in 10,000. The median age was seven years (interquartile range four-15 years) with a male predominance of 86.7% (13/15). The severity of anaphylaxis was Grade 2 in 33.3% (5/15) and Grade 3 in 66.7% (10/15). The commonest presenting feature was hypotension (13/15, 86.7%) while the earliest symptom was respiratory change (9/15, 60.0%). Dynamic tryptase was raised in 75% (6/8) of the patients with adequate tryptase samples. Eight patients (53.3%) completed allergy testing, of whom five patients (62.5%) had IgE-mediated anaphylaxis with skin test positive to cefazolin (n = 3), atracurium (n = 1) and rocuronium (n = 1). Three patients (25.0%) had non-IgE-mediated reactions with negative skin tests. Although only half the patients completed allergy evaluation, a culprit drug could be identified in 62.5%, with antibiotics being the commonest. This emphasises the need for appropriate evaluation in cases of suspected perioperative anaphylaxis.
Transformations of Ferric Chloride-Generated Stilbene Cation Radicals. The Effect of Aromatic Substitution and a Comparison with Anodic Oxidation

Hong FJ, Chong KW, Low YY, Thomas NF, Kam TS

Chem Asian J, 2015 Oct;10(10):2207-20.
PMID: 26097065 DOI: 10.1002/asia.201500488

A systematic study on the FeCl3-induced oxidation of 1,2-diarylalkenes was carried out with the focus on the variation of product type as a function of aromatic substitution, as well as to compare the reactivity of stilbene cation radicals generated via Fe(III) oxidation with those generated by anodic oxidation. The aromatic substituents were found to fall into three main categories, namely those that give rise to tetralins and/or dehydrotetralins, those that give products possessing pallidol and ampelopsin F-type carbon skeletons, and last, those that give rise to trimeric products, indanes, and dehydrotetralins/tetralins. The latter are those stilbenes with a para-methoxy substituent in one ring and a para- or meta-EWG (CF3, NO2, Cl, F) in the other, and represent the most prominent departure when compared with the behavior of the same stilbenes under the conditions of anodic oxidation. Reaction pathways to rationalize the formation of the different products are presented.
Biosynthetic Enantiodivergence in the Eburnane Alkaloids from Kopsia

Chong KW, Yeap JS, Lim SH, Weber JF, Low YY, Kam TS

J Nat Prod, 2017 11 22;80(11):3014-3024.
PMID: 29087707 DOI: 10.1021/acs.jnatprod.7b00621

Reexamination of the absolute configuration of recently isolated eburnane alkaloids from Malaysian Kopsia and Leuconotis species by X-ray diffraction analysis and ECD/TDDFT has revealed the existence of biosynthetic enantiodivergence. Three different scenarios are discerned with respect to the composition of the enantiomeric eburnane alkaloids in these plants: first, where the new eburnane congeners possess the same C-20, C-21 absolute configurations as the common eburnane alkaloids (eburnamonine, eburnamine, isoeburnamine, eburnamenine) occurring in the same plant; second, where the new eburnane congeners possess opposite or enantiomeric C-20, C-21 absolute configurations compared to the common eburnane alkaloids found in the same plant; and, third, where the four common eburnane alkaloids were isolated as racemic or scalemic mixtures, while the new eburnane congeners were isolated as pure enantiomers with a common C-20, C-21 configuration (20α, 21α). Additionally, the same Kopsia species (K. pauciflora) found in two different geographical locations (Peninsular Malaysia and Malaysian Borneo) showed different patterns in the composition of the enantiomeric eburnane alkaloids. Revision of the absolute configurations of a number of new eburnane congeners (previously assigned based on the assumption of a common biogenetic origin to that of the known eburnane alkaloids co-occurring in the same plant) is required based on the present results.
Unusual phenethylamine-containing alkaloids from Elaeocarpus tectorius

Ezeoke MC, Krishnan P, Sim DS, Lim SH, Low YY, Chong KW, et al.

Phytochemistry, 2018 Feb;146:75-81.
PMID: 29247894 DOI: 10.1016/j.phytochem.2017.12.003

From the leaves of Elaeocarpus tectorius (Lour.) Poir. four previously undescribed phenethylamine-containing alkaloids were isolated, namely, tectoricine, possessing an unprecedented isoquinuclidinone ring system incorporating a phenethylamine moiety, tectoraline, representing a rare alkamide incorporating two phenethylamine moieties, and tectoramidines A and B, representing the first naturally occurring trimeric and dimeric phenethylamine alkaloids incorporating an amidine function. The structures of these alkaloids were established by detailed spectroscopic analysis. The absolute configuration of tectoricine was determined by comparison of the experimental and calculated ECD spectra. Plausible biosynthetic pathways to the four alkaloids are proposed.
Fulltext Assessing Financial Risk Spillover and Panic Impact of Covid-19 on European and Vietnam Stock market

Moslehpour M, Al-Fadly A, Ehsanullah S, Chong KW, Xuyen NTM, Tan LP

Environ Sci Pollut Res Int, 2022 Apr;29(19):28226-28240.
PMID: 34993822 DOI: 10.1007/s11356-021-18170-2

This study examined the influence of tail risks on global financial markets, which aids in better understanding of the emergence of COVID-19. This study looks at the global and Vietnamese stock markets impacted by the COVID-19 pandemic to identify systemic emergencies. Risk dependent value (CoVaR) and Delta link VaR are two important tail-related risk indicators used in Conditional Bivariate Dynamic Correlation (DCC) (CoVaR). The empirical findings demonstrate that when COVID-19's worldwide spread widens, the volatility transmission of systemic risks across the global stock market and multiple exchanges shifts and becomes more relevant over time. At the time of COVID-19, the world industrial market was larger than the Vietnamese stock market, and the Vietnamese stock market posed a lesser danger to the global market. A closer examination of the link between the Vietnam value-at-risk (VaR) range index sample and the world stock index indicates a significant degree of downside risk integration in key monetary systems, particularly during the COVID-19 era. Our study findings may help regulators, politicians, and portfolio risk managers in Vietnam and worldwide during the unique moment of uncertainty created by the COVID-19 epidemic.
Electrochemically Mediated Oxidative Transformations of Substituted 4-Methoxystilbenes: Effect of Ortho-Substituted Nucleophilic Groups

Chong KW, Hong FJ, Thomas NF, Low YY, Kam TS

J Org Chem, 2017 06 16;82(12):6172-6191.
PMID: 28552001 DOI: 10.1021/acs.joc.7b00753

A systematic study was undertaken to determine the influence of ortho'-substituted nucleophilic groups (OH, NH2, or NHR) on the reactivity of anodically generated 4-methoxy- and 3,4-dimethoxystilbene cation radicals. The results showed that when ortho-substituted nucleophilic groups such as OH and NHR are present in the other ring, both direct and crossover intramolecular cation-nucleophile reactions occur to give bisbenzofurans/bisindoles or fused bisbenzopyrans/bisquinolines, respectively. Where an additional 3-methoxy substituent is present, bridged oxocine/azocine products are formed in addition to the bisbenzopyrans/bisquinolines and bisbenzofurans/bisindoles. Mechanistic rationalization of the observed behavior is presented based on a generalized pathway involving fast cation radical dimerization following electron transfer, followed by direct and crossover trapping of the benzylic cations by the ortho-substituted oxygen and nitrogen nucleophilic groups. In the instances where an additional 3-methoxy group is present, the bridged oxocine/azocine products are also formed as a result of competing aromatic substitution (Friedel-Crafts reaction). The results have shed further light and provided additional clarification on the reactivity of anodically generated stilbene cation radicals.
Biomimetic oxidative dimerization of anodically generated stilbene radical cations: effect of aromatic substitution on product distribution and reaction pathways

Hong FJ, Low YY, Chong KW, Thomas NF, Kam TS

J Org Chem, 2014 May 16;79(10):4528-43.
PMID: 24754525 DOI: 10.1021/jo500559r

A systematic study of the electrochemical oxidation of 1,2-diarylalkenes was carried out with the focus on detailed product studies and variation of product type as a function of aromatic substitution. A reinvestigation of the electrochemical oxidation of 4,4'-dimethoxystilbene under various conditions was first carried out, and all products formed were fully characterized and quantitated. This was followed by a systematic investigation of the effect of aromatic substitution on the nature and distribution of the products. The aromatic substituents were found to fall into three main categories, viz., substrates in which the nature and position of the aromatic substituents gave rise to essentially the same products as 4,4'-dimethoxystilbene, for example, tetraaryltetrahydrofurans, dehydrotetralins, and aldehydes (p-MeO or p-NMe2 on one ring and X on the other ring, where X = o-MeO or p-alkyl, or m- or p-EWG; e.g., 4-methoxy-4'-trifluoromethylstilbene); those that gave rise to a mixture of indanyl (or tetralinyl) acetamides and dehydrotetralins (or pallidols) (both or one ring substituted by alkyl groups, e.g., 4,4'-dimethylstilbene); and those where strategic placement of donor groups, such as OMe and OH, led to the formation of ampelopsin F and pallidol-type carbon skeletons (e.g., 4,3',4'-trimethoxystilbene). Reaction pathways to rationalize the formation of the different products are presented.
Alstoscholactine and Alstolaxepine, Monoterpenoid Indole Alkaloids with γ-Lactone-Bridged Cycloheptane and Oxepane Moieties from Alstonia scholaris

Krishnan P, Lee FK, Chong KW, Mai CW, Muhamad A, Lim SH, et al.

Org. Lett., 2018 12 21;20(24):8014-8018.
PMID: 30543301 DOI: 10.1021/acs.orglett.8b03592

Two new monoterpenoid indole alkaloids, alstoscholactine (1) and alstolaxepine (2), were isolated from Alstonia scholaris. Compound 1 represents a rearranged stemmadenine alkaloid with an unprecedented C-6-C-19 connectivity, whereas compound 2 represents a 6,7- seco-angustilobine B-type alkaloid incorporating a rare γ-lactone-bridged oxepane ring system. Their structures and absolute configurations were determined by spectroscopic analyses. Compound 1 was successfully semisynthesized from 19 E-vallesamine. Compound 2 induced marked vasorelaxation in rat isolated aortic rings precontracted with phenylephrine.
A Bis-benzopyrroloisoquinoline Alkaloid Incorporating a Cyclobutane Core and a Chlorophenanthroindolizidine Alkaloid with Cytotoxic Activity from Ficus fistulosa var. tengerensis

Al-Khdhairawi AAQ, Krishnan P, Mai CW, Chung FF, Leong CO, Yong KT, et al.

J Nat Prod, 2017 10 27;80(10):2734-2740.
PMID: 28926237 DOI: 10.1021/acs.jnatprod.7b00500

Tengerensine (1), isolated as a racemate and constituted from a pair of bis-benzopyrroloisoquinoline enantiomers, and tengechlorenine (2), purified as a scalemic mixture and constituted from a pair of chlorinated phenanthroindolizidine enantiomers, were isolated from the leaves of Ficus fistulosa var. tengerensis, along with three other known alkaloids. The structures of 1 and 2 were determined by spectroscopic data interpretation and X-ray diffraction analysis. The enantiomers of 1 were separated by chiral-phase HPLC, and the absolute configurations of (+)-1 and (-)-1 were established via experimental and calculated ECD data. Compound 1 is notable in being a rare unsymmetrical cyclobutane adduct and is the first example of a dimeric benzopyrroloisoquinoline alkaloid, while compound 2 represents the first naturally occurring halogenated phenanthroindolizidine alkaloid. Compound (+)-1 displayed a selective in vitro cytotoxic effect against MDA-MB-468 cells (IC50 7.4 μM), while compound 2 showed pronounced in vitro cytotoxic activity against all three breast cancer cell lines tested (MDA-MB-468, MDA-MB-231, and MCF7; IC50 values of 0.038-0.91 μM).
Fulltext REKOVER study protocol: a pRospective patient treatment rEgistry of tramadol and dexKetoprofen trometamol oral fixed-dose combination (SKUDEXA) in mOderate to seVere acutE pain in Real-world setting in Asia

Ho KY, Gyanwali B, Dimayuga C, Eufemio EM, Bernardo E, Raju G, et al.

BMJ Open, 2024 Mar 19;14(3):e080620.
PMID: 38508619 DOI: 10.1136/bmjopen-2023-080620

INTRODUCTION: Satisfactory management of acute pain remains a major medical challenge despite the availability of multiple therapeutic options including the fixed-dose combination (FDC) drugs. Tramadol and dexketoprofen trometamol (TRAM/DKP) 75/25 mg FDC was launched in 2018 in Asia and is widely used in the management of moderate to severe acute pain. There are limited data on its effectiveness and safety in Asian patients, and therefore, a need to better understand its usage patterns in clinical practice. We aim to understand the usage pattern of TRAM/DKP FDC, its effectiveness and tolerability in patients with moderate to severe acute pain in Asia.
METHODS AND ANALYSIS: REKOVER is a phase-IV, multicountry, multicentre, prospective, real-world observational study. A total of 750 postsurgical and non-surgical patients (male and female, aged 18-80 years) will be recruited from 13 tertiary-care hospitals (15 sites) in Singapore, Thailand, the Philippines and Malaysia. All patients prescribed with TRAM/DKP FDC and willing to participate in the study will be enrolled. The recruitment duration for each site will be 6 months. The severity of pain will be collected using Numeric Pain Rating Scale through the treatment period from day 1 to day 5, while satisfaction with the treatment will be evaluated using Patient Global Evaluation Scale at the end of treatment. Any adverse event reported during the study duration will be recorded for safety analysis (up to day 6). The study data will be entered into the ClaimIt portal and mobile application (app) (ObvioHealth, USA). All the inpatient data will be entered into the portal by the study site and for outpatient it will be done by patients through an app.
ETHICS AND DISSEMINATION: The study has been approved by the local ethics committee from each study sites in Singapore, Thailand, the Philippines and Malaysia. Findings will be disseminated through local and global conference presentations, publications in peer-reviewed scientific journals and continuing medical education.

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