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  1. Lau TTV, Tan JMA, Puthucheary SD, Puah SM, Chua KH
    Braz J Microbiol, 2020 Sep;51(3):909-918.
    PMID: 32067209 DOI: 10.1007/s42770-020-00239-8
    Aeromonas dhakensis is an emergent human pathogen with medical importance. This study was aimed to determine the sequence types (STs), genetic diversity, and phylogenetic relationships of different clinical sources of 47 A. dhakensis from Malaysia using multilocus sequence typing (MLST), goeBURST, and phylogenetic analyses. The analysis of a concatenated six-gene tree with a nucleotide length of 2994 bp based on six housekeeping genes (gyrB, groL, gltA, metG, ppsA, and recA) and independent analyses of single gene fragments was performed. MLST was able to group 47 A. dhakensis from our collection into 36 STs in which 34 STs are novel STs. The most abundant ST521 consisted of five strains from peritoneal fluid and two strains from stools. Comparison of 62 global A. dhakensis was carried out via goeBURST; 94.4% (34/36) of the identified STs are novel and unique in Malaysia. Two STs (111 and 541) were grouped into clonal complexes among our strains and 32 STs occurred as singletons. Single-gene phylogenetic trees showed varying topologies; groL and rpoD grouped all A. dhakensis into a tight-cluster with bootstrap values of 100% and 99%, respectively. A poor phylogenetic resolution encountered in single-gene analyses was buffered by the multilocus phylogenetic tree that offered high discriminatory power (bootstrap value = 100%) in resolving all A. dhakensis from A. hydrophila and delineating the relationship among other taxa. Genetic diversity analysis showed groL as the most conserved gene and ppsA as the most variable gene. This study revealed novel STs and high genetic diversity among clinical A. dhakensis from Malaysia.
  2. Ong GH, Yap CK, Mahmood M, Tan SG, Hamzah S
    Trop Life Sci Res, 2013 Aug;24(1):55-70.
    PMID: 24575242
    In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [μg/g dry weight (dw)] was 63.72 to 382.01 μg/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 μg/g for roots, 3.31 to 11.22 μg/g for leaves and 2.37 to 6.14 μg/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leaves-soils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution.
  3. Hamdan NE, Ng YL, Lee WB, Tan CS, Khan FA, Chong YL
    Trop Life Sci Res, 2017 Jan;28(1):151-159.
    PMID: 28228923 MyJurnal DOI: 10.21315/tlsr2017.28.1.11
    Rodents belong to the order Rodentia, which consists of three families in Borneo (i.e., Muridae, Sciuridae and Hystricidae). These include rats, mice, squirrels, and porcupines. They are widespread throughout the world and considered pests that harm humans and livestock. Some rodent species are natural reservoirs of hantaviruses (Family: Bunyaviridae) that can cause zoonotic diseases in humans. Although hantavirus seropositive human sera were reported in Peninsular Malaysia in the early 1980s, information on their infection in rodent species in Malaysia is still lacking. The rodent populations in residential and forested areas in Sarawak were sampled. A total of 108 individuals from 15 species of rodents were collected in residential (n = 44) and forested ( n = 64) areas. The species diversity of rodents in forested areas was significantly higher (H = 2.2342) compared to rodents in residential areas (H = 0.64715) (p < 0.001 of Zar-t test based on the Shannon index). Rattus rattus and Sundamys muelleri were present at high frequencies in both localities. An enzyme-linked immunosorbent assay (ELISA) showed that hantavirus-targeting antibodies were absent from 53 tested serum samples. This is the first report of hantavirus seroprevalence surveillance in rodent populations in Sarawak, East Malaysia. The results suggested that hantavirus was not circulating in the studied rodent populations in Sarawak, or it was otherwise at a low prevalence that is below the detection threshold. It is important to remain vigilant because of the zoonotic potential of this virus and its severe disease outcome. Further studies, such as molecular detection of viral genetic materials, are needed to fully assess the risk of hantavirus infection in rodents and humans in this region of Malaysia.
  4. Syamsul VS, Okene IA, Yahya SNC, Hamdan RH, Lee SH, Tan LP
    Trop Life Sci Res, 2020 Apr;31(1):45-56.
    PMID: 32963710 DOI: 10.21315/tlsr2020.31.1.3
    Kelantan is a chiefly agrarian state with abundant small-holder ruminant farms in the East Coast economic Region of Malaysia. Ectoparasitism affects small ruminant production in Malaysia. It often causes reduction in meat quality and milk production which affect the farmers' income. To date, no report for the prevalence of ectoparasitism on small ruminant in Kelantan compared to other state in Malaysia. This study aims to determine the prevalence and associated risk factor of ruminant ectoparasitism in Kelantan. Ectoparasites were collected by manual picking and skin scrapping from 462 sheep and goats in Kelantan between April and September 2017 (during dry season). 60% of the sampled animals were infested with at least one species of the ectoparasites. In this study, lice and ticks were the most prevalent ectoparasites on small ruminant, which were 43.64% and 22.98%, respectively. The high biotic potential of lice population on host might be one of the factors they become the most prevalent species found on the animals. There was no significant relationship between ectoparasitism prevalence and species of small ruminants (χ2 = 1.12, p = 0.293). However, there was significant variations in prevalence between the regions where the animals were sampled from (χ2 = 30.25, p = 0.002) and farm management system for both species. This present study provides baseline epidemiological data on the prevalence of ectoparasitism in small ruminant. This information is useful for the formulation of prevention and control measures in order to enhance ruminant productivity in Kelantan.
  5. Wong YP, Yahaya A, Che Abdul Aziz R, Chia PY, Loh CK, Tan GC
    Malays J Pathol, 2020 Aug;42(2):301-305.
    PMID: 32860387
    INTRODUCTION: Yolk sac tumour (YST) or endodermal sinus tumour is rare and typically seen in gonads.

    CASE REPORT: We described a case of extragonadal vaginal YST in a one year and seven months old girl who presented with vaginal discharge and bleeding, and discuss its differential diagnosis and potential pitfalls in immunohistochemistry. She was found to have a suprapubic mass on examination. The serum alpha fetoprotein was 11919.4 ng/mL. Computed tomography of the pelvis revealed a large 6.4 cm heterogenous pelvic mass. Colposcopic examination of the pelvis showed a fungating vaginal mass that was subsequently confirmed as a yolk sac tumour. Immunohistochemically, the malignant cells were positive toward CKAE1/AE3, AFP and glypican-3, as well as CD117.

    DISCUSSION: Solid pattern extragonadal vaginal YST may morphologically resemble dysgerminoma that is also CD117 positive, while the glandular pattern YST may have clear cytoplasm and is positive for cytokeratin; hence, may resemble clear cell carcinoma. Being mindful of these potential diagnostic caveats is necessary to prevent misdiagnosis.

  6. Lai D, Zhou A, Tan BK, Tang Y, Sarah Hamzah S, Zhang Z, et al.
    Food Chem, 2021 Nov 01;361:130117.
    PMID: 34058659 DOI: 10.1016/j.foodchem.2021.130117
    To overcome the poor water solubility of curcumin, a curcumin-β-cyclodextrin (Cur-β-CD) complex was prepared as a novel photosensitizer. Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to verify the formation of Cur-β-CD. Furthermore, the ROS generation capacity and photodynamic bactericidal effect were measured to confirm this Cur-β-CD complex kept photodynamic activity of curcumin. The result showed Cur-β-CD could effectively generate ROS upon blue-light irradiation. The plate count assay demonstrated Cur-β-CD complex possess desirable photodynamic antibacterial effect against food-borne pathogens including Staphylococcus aureus, Listeria monocytogenes and Escherichia coli. The cell morphology determined by scanning electron microscope (SEM) and transmission electron microscope (TEM) showed Cur-β-CD could cause cell deformation, surface collapse and cell structure damage of the bacteria, resulting in the leakage of cytoplasmic; while agarose gel electrophoresis and SDS-PAGE further illustrated the inactivation mechanisms by Cur-β-CD involve bacterial DNA damage and protein degradation.
  7. Yeo KT, Kong JY, Sasi A, Tan K, Lai NM, Schindler T
    Cochrane Database Syst Rev, 2019 10 28;2019(10).
    PMID: 31684689 DOI: 10.1002/14651858.CD012888.pub2
    BACKGROUND: Feeding practices around the time of packed red blood cell transfusion have been implicated in the subsequent development of necrotising enterocolitis (NEC) in preterm infants. Specifically, it has been suggested that withholding feeds around the time of transfusion may reduce the risk of subsequent NEC. It is important to determine if withholding feeds around transfusion reduces the risk of subsequent NEC and associated mortality.

    OBJECTIVES: • To assess the benefits and risks of stopping compared to continuing feed management before, during, and after blood transfusion in preterm infants • To assess the effects of stopping versus continuing feeds in the following subgroups of infants: infants of different gestations; infants with symptomatic and asymptomatic anaemia; infants who received different feeding schedules, types of feed, and methods of feed delivery; infants who were transfused with different blood products, at different blood volumes, via different routes of delivery; and those who received blood transfusion with and without co-interventions such as use of diuretics • To determine the effectiveness and safety of stopping feeds around the time of a blood transfusion in reducing the risk of subsequent necrotising enterocolitis (NEC) in preterm infants SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 11), in the Cochrane Library; MEDLINE (1966 to 14 November 2018); Embase (1980 to 14 November 2018); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 14 November 2018). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials (RCTs), cluster-RCTs, and quasi-RCTs.

    SELECTION CRITERIA: Randomised and quasi-randomised controlled trials that compared stopping feeds versus continuing feeds around the time of blood transfusion in preterm infants.

    DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials, assessed trial quality, and extracted data from the included studies.

    MAIN RESULTS: The search revealed seven studies that assessed effects of stopping feeds during blood transfusion. However, only one RCT involving 22 preterm infants was eligible for inclusion in the review. This RCT had low risk of selection bias but high risk of performance bias, as care personnel were not blinded to the study allocation. The primary objective of this trial was to investigate changes in mesenteric blood flow, and no cases of NEC were reported in any of the infants included in the trial. We were unable to draw any conclusions from this single study. The overall GRADE rating for quality of evidence was very low.

    AUTHORS' CONCLUSIONS: Randomised controlled trial evidence is insufficient to show whether stopping feeds has an effect on the incidence of subsequent NEC or death. Large, adequately powered RCTs are needed to address this issue.

  8. Shaharudin SM, Ismail S, Hassan NA, Tan ML, Sulaiman NAF
    Front Public Health, 2021;9:604093.
    PMID: 34195166 DOI: 10.3389/fpubh.2021.604093
    Novel coronavirus (COVID-19) was discovered in Wuhan, China in December 2019, and has affected millions of lives worldwide. On 29th April 2020, Malaysia reported more than 5,000 COVID-19 cases; the second highest in the Southeast Asian region after Singapore. Recently, a forecasting model was developed to measure and predict COVID-19 cases in Malaysia on daily basis for the next 10 days using previously-confirmed cases. A Recurrent Forecasting-Singular Spectrum Analysis (RF-SSA) is proposed by establishing L and ET parameters via several tests. The advantage of using this forecasting model is it would discriminate noise in a time series trend and produce significant forecasting results. The RF-SSA model assessment was based on the official COVID-19 data released by the World Health Organization (WHO) to predict daily confirmed cases between 30th April and 31st May, 2020. These results revealed that parameter L = 5 (T/20) for the RF-SSA model was indeed suitable for short-time series outbreak data, while the appropriate number of eigentriples was integral as it influenced the forecasting results. Evidently, the RF-SSA had over-forecasted the cases by 0.36%. This signifies the competence of RF-SSA in predicting the impending number of COVID-19 cases. Nonetheless, an enhanced RF-SSA algorithm should be developed for higher effectivity of capturing any extreme data changes.
  9. Wan J, Yuan J, Li X, Bao Y, Hou Y, Li Z, et al.
    Complement Ther Med, 2020 Nov;54:102579.
    PMID: 33183675 DOI: 10.1016/j.ctim.2020.102579
    OBJECTIVE: Although many studies have attempted to unravel the relationship between vitamin D deficiency and the incidence of VTE, the results remained inconsistent. To address this discrepancy, we performed a systematic review and meta-analysis to precisely disentangle the relationship between serum vitamin D levels and VTE risk.

    METHODS: The Web of Science, Scopus, PubMed/Medline, Embase, and Google Scholar databases were searched for all available observational studies that reported the risk of venous thromboembolism (VTE) based on serum vitamin D levels categories. The search was performed up to March 2020.

    RESULTS: Seven studies were included. The overall analysis showed a significantly increased risk of VTE in subjects with low levels of serum vitamin D compared with those with normal vitamin D levels (RR = 1.34; 95% CI: 1.07-1.69; P = 0.011). In a sensitivity analysis, we did not observe a significant effect of any individual study on the combined effect sizes. Nevertheless, significant heterogeneity was present among the studies (Cochrane Q test, p = 0.018, I2 = 61%). In the stratified analysis, low vitamin D levels were positively associated with an increased risk of VTE in prospective population-based studies (RR = 1.31; 95% CI: 1.06-1.61; P = 0.010) and in subjects below 60 years old (RR = 1.28; 95% CI: 1.07-1.54; P = 0.060).

    CONCLUSION: our systematic review and meta-analysis showed that a low serum vitamin D level was indeed associated with an increased risk of VTE.

  10. Kamgang J, Tétinou F, Zolo Y, Tan CY, Wambo C, Fongang EJN, et al.
    Neurol Res Int, 2021;2021:9948990.
    PMID: 34221504 DOI: 10.1155/2021/9948990
    Introduction: Stroke recurrence accounts for a great percentage of catastrophic complications, yet no comprehensive study has analyzed the factors associated with stroke recurrence in Cameroon. We carried out this case-control study to better understand the factors associated with the stroke recurrence in Cameroon.

    Methods: We collected sociodemographic, clinical, neuroimaging, laboratory, and therapeutic data of eligible patients who consulted the neurology and cardiology department of the Yaounde Central Hospital in Cameroon. We included all patients at least five years removed from their first stroke event who consulted the authors' institution as of January 15, 2019. Wilcoxon signed-rank and Fisher's exact tests were used. Also, a Cox regression model was used to identify confounders.

    Results: We recruited 100 patients; seven out of ten patients had hypertension, while six out of 10 had a sedentary lifestyle. Half of the patients consumed alcohol regularly, while one patient out of five had diabetes. Most patients presented with their first stroke event, and a quarter had a stroke recurrence. Stroke recurrence was associated with right handedness (OR = 0.23, 95% CI = 0.16-0.33), congestive heart failure (OR = 3.45, 95% CI = 1.16-10.28), gout (OR = 4.34, 95% CI = 1.09-18.09), dysarthria (OR = 4.34, 95% CI = 1.30-14.54), and facial palsy (OR = 3.96, 95% CII = 1.49 - 10.51), as well as modifiable factors such as elevated abdominal circumference (P 

  11. Ng HF, Tan JL, Zin T, Yap SF, Ngeow YF
    J Med Microbiol, 2018 Dec;67(12):1676-1681.
    PMID: 30351265 DOI: 10.1099/jmm.0.000857
    In this study, we characterized 7C, a spontaneous mutant selected from tigecycline-susceptible Mycobacterium abscessus ATCC 19977. Whole-genome sequencing (WGS) was used to identify possible resistance determinants in this mutant. Compared to the wild-type, 7C demonstrated resistance to tigecycline as well as cross-resistance to imipenem, and had a slightly retarded growth rate. WGS and subsequent biological verifications showed that these phenotypes were caused by a point mutation in MAB_3542c, which encodes an RshA-like protein. In Mycobacterium tuberculosis, RshA is an anti-sigma factor that negatively regulates the heat/oxidative stress response mechanisms. The MAB_3542c mutation may represent a novel determinant of tigecycline resistance. We hypothesize that this mutation may dysregulate the stress-response pathways which have been shown to be linked to antibiotic resistance in previous studies.
  12. Puah SM, Khor WC, Kee BP, Tan JAMA, Puthucheary SD, Chua KH
    J Med Microbiol, 2018 Sep;67(9):1271-1278.
    PMID: 30024365 DOI: 10.1099/jmm.0.000796
    PURPOSE: The taxonomy of Aeromonas keeps expanding and their identification remains problematic due to their phenotypic and genotypic heterogeneity. In this study, we aimed to develop a rapid and reliable polymerase chain reaction-restriction fragment length polymorphism assay targeting the rpoD gene to enable the differentiation of aeromonads into 27 distinct species using microfluidic capillary electrophoresis.

    METHODOLOGY: A pair of degenerate primers (Aero F: 5'-YGARATCGAYATCGCCAARCGB-3' and Aero R: 5'-GRCCDATGCTCATRCGRCGGTT-3') was designed that amplified the rpoD gene of 27 Aeromonas species. Subsequently, in silico analysis enabled the differentiation of 25 species using the single restriction endonuclease AluI, while 2 species, A. sanarelli and A. taiwanensis, required an additional restriction endonuclease, HpyCH4IV. Twelve type strains (A. hydrophila ATCC7966T, A. caviae ATCC15468T, A. veronii ATCC9071T, A. media DSM4881T, A. allosaccharophila DSM11576T, A. dhakensis DSM17689T, A. enteropelogens DSM7312T, A. jandaei DSM7311T, A. rivuli DSM22539T, A. salmonicida ATCC33658T, A. taiwanensis DSM24096T and A. sanarelli DSM24094T) were randomly selected from the 27 Aeromonas species for experimental validation.Results/key findings. The twelve type strains demonstrated distinctive RFLP patterns and supported the in silico digestion. Subsequently, 60 clinical and environmental strains from our collection, comprising nine Aeromonas species, were used for screening examinations, and the results were in agreement.

    CONCLUSION: This method provides an alternative method for laboratory identification, surveillance and epidemiological investigations of clinical and environmental specimens.

  13. Foo PC, Chan YY, See Too WC, Tan ZN, Wong WK, Lalitha P, et al.
    J Med Microbiol, 2012 Sep;61(Pt 9):1219-1225.
    PMID: 22556327 DOI: 10.1099/jmm.0.044552-0
    Entamoeba histolytica is the only Entamoeba species that causes amoebiasis in humans. Approximately 50 million people are infected, with 100, 000 deaths annually in endemic countries. Molecular diagnosis of Entamoeba histolytica is important to differentiate it from the morphologically identical Entamoeba dispar to avoid unnecessary medication. Conventional molecular diagnostic tests require trained personnel, cold-chain transportation and/or are storage-dependent, which make them user-unfriendly. The aim of this study was to develop a thermostabilized, one-step, nested, tetraplex PCR assay for the detection of Entamoeba histolytica, Entamoeba dispar and Entamoeba species in cold-chain-free and ready-to-use form. The PCR test was designed based on the Entamoeba small subunit rRNA (SSU-rRNA) gene, which detects the presence of any Entamoeba species, and simultaneously can be used to differentiate Entamoeba histolytica from Entamoeba dispar. In addition, a pair of primers was designed to serve as an internal amplification control to help identify inhibitors in the samples. All PCR reagents together with the designed primers were thermostabilized by lyophilization and were stable at 24 °C for at least 6 months. The limit of detection of the tetraplex PCR was found to be 39 pg DNA or 1000 cells for Entamoeba histolytica and 78 pg DNA or 1000 cells for Entamoeba dispar, and the specificity was 100 %. In conclusion, this cold-chain-free, thermostabilized, one-step, nested, multiplex PCR assay was found to be efficacious in differentiating Entamoeba histolytica from other non-pathogenic Entamoeba species.
  14. Ibrahim AF, Tan MP, Teoh GK, Muda SM, Chong MC
    Exp Aging Res, 2021 Jul 06.
    PMID: 34229584 DOI: 10.1080/0361073X.2021.1939563
    BACKGROUND: Social disengagement among older persons may result from accumulated physical impact and social stressors experienced throughout life. Conversely, interventions that enhance social participation addresses social isolation with positive influences on health. This article, therefore, aimed to review the range of published studies that evaluated the health benefits of interventions on social participation among community-dwelling older persons.

    METHOD: We conducted a search using the databases CINAHL, MEDLINE, EBSCOhost, PubMed, ProQuest, SAGE, ScienceDirect, SpringerLink, Web of Science, and Open repository/archive.

    RESULTS: Twenty-five studies from Asia, Europe and America were selected. Included articles described randomized controlled trials (9), quasi-experimental studies (9), mixed-methods studies (2), participatory action research (3), and community-based intervention research (2). Social interventions described are group or cultural activities, personal/group monitoring and discussion, and communications devices. Intervention designed utilized theories, models, concepts, principles, and evidence from published literature.

    CONCLUSION: Most social intervention studies evaluating health outcomes have been conducted in North America and Western Europe. Group-based activities were most commonly employed, but personal/group discussions, home visits and technology-based interactions have also been used. While social isolation is now a widely accepted risk factor for ill-health, research evidence for improvement of health through reduction of social isolation remains limited.

  15. Sreedharan Nair R, Rahman H, Kong MX, Tan XY, Chen KY, Shanmugham S
    Turk J Pharm Sci, 2021 06 18;18(3):352-359.
    PMID: 34157826 DOI: 10.4274/tjps.galenos.2020.88725
    Objectives: N,N-Diethyl-3-methylbenzamide (DEET) is a broad-spectrum insect repellent that can easily permeate through the skin and can cause undesirable effects, especially in children and pregnant women. The objective of this research was to formulate and evaluate DEET-encapsulated microparticles containing a hydrogel designed to reduce skin permeation and prolong drug release.

    Materials and Methods: The formulation design was based on the independent formulation variables of the concentration of chitosan and sodium tripolyphosphate using a simple factorial design experiment. DEET-loaded microparticles were developed and incorporated into a hydrogel. The size of the microparticles was analyzed using the Zetasizer Nano® particle size analyzer, and the surface morphology, using field emission scanning electron microscopy. Drug release from the microparticles was determined by the dialysis bag method. A rheological evaluation of the formulated gel was performed using a Thermo Haake Rheometer. The in vitro permeation of the formulation was performed using a synthetic Strat-M® membrane.

    Results: The size of the microparticles ranged from 0.45 to 8.3 μm, and the encapsulation efficiencies were >50% for all the formulations. The drug-release curves showed no initial burst release from the microparticle formulation. Instead, a slow and controlled drug release was observed over 24 hours that followed Higuchi kinetics. The cumulative amount of DEET permeated (over 24 h) from the DEET solution (control), and the formulation was 211.6±19.5 μg/cm2 and 4.07±0.08 μg/cm2, respectively.

    Conclusion: A significantly low DEET permeation from the microparticle formulations indicated minimal absorption of the drug into the body and thus, reduced systemic toxicity. Thixotropic evaluation of the hydrogel formulation demonstrated a hysteresis loop that fitted closely to the Herschel-Bulkley rheological model, ensuring an effortless application and prolonged retention on the skin. Hence, it can be concluded that the developed formulation is an effective delivery approach for controlled insect repellent activity with reduced skin absorption.

  16. Koh HM, Chong PF, Tan JN, Chidambaram SK, Chua HJ
    J Clin Pharm Ther, 2021 Jun;46(3):800-806.
    PMID: 33768612 DOI: 10.1111/jcpt.13356
    WHAT IS KNOWN AND OBJECTIVE: Hydroxychloroquine and protease inhibitors were widely used as off-label treatment options for COVID-19 but the safety data of these drugs among the COVID-19 population are largely lacking. Drug-induced QTc prolongation is a known adverse reaction of hydroxychloroquine, especially during chronic treatment. However, when administered concurrently with potential pro-arrhythmic drugs such as protease inhibitors, the risk of QTc prolongation imposed on these patients is not known. We aim to investigate the incidence of QTc prolongation events and potential factors associated with its occurrence in COVID-19 population.

    METHODS: We included 446 SARS-CoV-2 RT-PCR-positive patients taking at least one treatment drug for COVID-19 within a period of one month (March-April 2020). In addition to COVID-19-related treatment (HCQ/PI), concomitant drugs with risks of QTc prolongation were considered. We defined QTc prolongation as QTc interval of ≥470 ms in postpubertal males, and ≥480 ms in postpubertal females.

    RESULTS AND DISCUSSION: QTc prolongation events occurred in 28/446 (6.3%) patients with an incidence rate of 1 case per 100 person-days. A total of 26/28 (93%) patients who had prolonged QTc intervals received at least two pro-QT drugs. Multivariate analysis showed that HCQ and PI combination therapy had five times higher odds of QTc prolongation as compared to HCQ-only therapy after controlling for age, cardiovascular disease, SIRS and the use of concurrent QTc-prolonging agents besides HCQ and/or PI (OR 5.2; 95% CI, 1.11-24.49; p = 0.036). Independent of drug therapy, presence of SIRS resulted in four times higher odds of QTc prolongation (OR 4.3; 95% CI, 1.66-11.06; p = 0.003). In HCQ-PI combination group, having concomitant pro-QT drugs led to four times higher odds of QTc prolongation (OR 3.8; 95% CI, 1.53-9.73; p = 0.004). Four patients who had prolonged QTc intervals died but none were cardiac-related deaths.

    WHAT IS NEW AND CONCLUSION: In our cohort, hydroxychloroquine monotherapy had low potential to increase QTc intervals. However, when given concurrently with protease inhibitors which have possible or conditional risk, the odds of QTc prolongation increased fivefold. Interestingly, independent of drug therapy, the presence of systemic inflammatory response syndrome (SIRS) resulted in four times higher odds of QTc prolongation, leading to the postulation that some QTc events seen in COVID-19 patients may be due to the disease itself. ECG monitoring should be continued for at least a week from the initiation of treatment.

  17. Chuman Y, Nobuhisa I, Ogawa T, Deshimaru M, Chijiwa T, Tan NH, et al.
    Toxicon, 2000 Mar;38(3):449-62.
    PMID: 10669032
    In accordance with detection of a few phospholipase A2 (PLA2) isozyme genes by Southern blot analysis, only two cDNAs, named NnkPLA-I , and NnkPLA-II, encoding group I PLA2s, NnkPLA-I and NnkPLA-II, respectively, were isolated from the venom gland cDNA library of Elapinae Naja naja kaouthia of Malaysia. NnkPLA-I and NnkPLA-II showed four amino acid substitutions, all of which were brought about by single nucleotide substitution. No existence of clones encoding CM-II and CM-III, PLA2 isozymes which had been isolated from the venom of N. naja kaouthia of Thailand, in Malaysian N. naja kaouthia venom gland cDNA library was verified by dot blot hybridization analysis with particular probes. NnkPLA-I and NnkPLA-II differed from CM-II and CM-III with four and two amino acid substitutions, respectively, suggesting that their molecular evolution is regional. The comparison of NnkPLA-I, NnkPLA-II and cDNAs encoding other group I snake venom gland PLA2s indicated that the 5'- and 3'-untranslated regions are more conserved than the mature protein-coding region and that the number of nucleotide substitutions per nonsynonymous site is almost equal to that per synonymous site in the protein-coding region, suggesting that accelerated evolution has occurred in group I venom gland PLA2s possibly to acquire new physiological functions.
  18. Daltry JC, Ponnudurai G, Shin CK, Tan NH, Thorpe RS, Wüster W
    Toxicon, 1996 Jan;34(1):67-79.
    PMID: 8835335
    The Malayan pit viper (Calloselasma rhodostoma) is of major clinical significance both as a leading cause of snakebite and as the source of ancrod (Arvin). Although its venom has been extensively studied, the degree to which venom composition varies between individuals is poorly known. We individually analysed the venoms of over 100 C. rhodostoma using isoelectric focusing. In all populations, females produced an intense band that was absent from all males, and significant ontogenetic variation was detected. Principal components analysis of the banding profiles also revealed strong geographic variation, which was significantly congruent with variation in the biological activities of the venom (phosphodiesterase, alkalinephosphoesterase, L-amino acid oxidase, arginine ester hydrolase, 5'-nucleotidase, thrombin-like enzyme, haemorrhagic activity). Studies of captive-bred snakes indicate that the intraspecific variation in venom is genetically inherited rather than environmentally induced. The intraspecific variation in venom composition and biological activity could be of applied importance to snakebite therapy, both in correct diagnosis of the source of envenomation and in the development of a more effective antivenom. Greater attention should be given to the source of C. rhodostoma venom used in research to ensure reproducibility of results.
  19. Tan HL, Abd Rahman R, Md Tarekh NA, Kassim M, Sathiamurthy N, Nik Mohamad Kamil A, et al.
    Med J Malaysia, 2021 05;76(3):441-445.
    PMID: 34031351
    Hunter Syndrome is a genetic disease characterized by deficiency of Iduronate-2-Sulfatase enzyme activity, resulting in accumulation of glycoaminoglycans in various organs including the central airways. We report a case of severe tracheomalacia and airway stenosis at Hospital Sultanah Aminah, Johor Bahru, Malaysia requiring mechanical ventilation in a middle aged gentleman who was previously undiagnosed of mucopolysaccharidosis. The patient underwent emergency tracheostomy for failed intubation, when he presented with shortness of breath and acute respiratory failure. A contrast-enhanced computed tomography of the neck and thorax revealed that the trachea distal to the tracheostomy tube had collapsed with narrowed right and left main bronchus. These findings were confirmed via direct visualization of the airway through a flexible bronchoscopy. Eventually, a tracheal stenting were performed to maintain the airway patency and assist in weaning off from mechanical ventilation. Further investigations to identify the aetiology of the central airway stenosis revealed elevated urinary glycoaminoglycans and the absence of iduronate-2-Sulfatase activity tested on dried blood spots, thus confirming the diagnosis of Hunter Syndrome. Managing mucopolysacharidosis with central airway obstruction requires multidisciplinary team effort in handling the difficult airway, anaesthesiology risk, potential comorbidities and providing genetic counselling.
  20. Chan YH, Liew KY, Tan JW, Shaari K, Israf DA, Tham CL
    Front Pharmacol, 2021;12:736339.
    PMID: 34531753 DOI: 10.3389/fphar.2021.736339
    2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) is a bioactive phloroglucinol compound found in Melicope pteleifolia (Champ. ex Benth.) T.G.Hartley, a medicinal plant vernacularly known as "tenggek burung". A variety of phytochemicals have been isolated from different parts of the plant including leaves, stems, and roots by using several extraction methods. Specifically, tHGA, a drug-like compound containing phloroglucinol structural core with acyl and geranyl group, has been identified in the methanolic extract of the young leaves. Due to its high nutritional and medicinal values, tHGA has been extensively studied by using various experimental models. These studies have successfully discovered various interesting pharmacological activities of tHGA such as anti-inflammatory, endothelial and epithelial barrier protective, anti-asthmatic, anti-allergic, and anti-cancer. More in-depth investigations later found that these activities were attributable to the modulatory actions exerted by tHGA on specific molecular targets. Despite these findings, the association between the mechanisms and signaling pathways underlying each pharmacological activity remains largely unknown. Also, little is known about the medicinal potentials of tHGA as a drug lead in the current pharmaceutical industry. Therefore, this mini review aims to summarize and relate the pharmacological activities of tHGA in terms of their respective mechanisms of action and signaling pathways in order to present a perspective into the overall modulatory actions exerted by tHGA. Besides that, this mini review will also pinpoint the unexplored potentials of this compound and provide some valuable insights into the potential applications of tHGA which may serve as a guide for the development of modern medication in the future.
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