1.Successful preimplantation genetic diagnosis of Hb Bart's hydrops fetalis in Singapore after fresh and frozen embryo replacement cycles.
Christine YAP ; Wen WANG ; Arnold S C TAN ; Wei Chin TAN ; Mui Nee LIM ; Samuel S CHONG
Annals of the Academy of Medicine, Singapore 2009;38(10):910-913
INTRODUCTIONWe report the fi rst successful preimplantation genetic diagnosis (PGD) for Hb Bart's hydrops fetalis in Singapore, involving both fresh and frozen embryo replacement cycles.
CLINICAL PICTURETwo couples who were carriers of the Southeast Asian type double gene deletion (--(SEA) deletion carriers) requested for PGD. Couple A had 2 previous affected pregnancies, while couple B have a child of unknown genotypic status.
TREATMENTOne PGD cycle was performed for each couple. The --(SEA) deletion was detected using a gap-PCR strategy. Couple A had 1 fresh-embryo replacement cycle while couple B underwent 2 frozen-embryo replacement cycles.
OUTCOMECouple A achieved a twin pregnancy. Second trimester complications resulted in premature delivery, where 1 baby girl survived. Couple B achieved a singleton pregnancy resulting in delivery of a healthy baby boy. Genotype analysis of all babies confirmed the PGD results consistent with clinically unaffected status.
CONCLUSIONSWe have successfully performed PGD to avoid Hb Bart's hydrops fetalis syndrome.
Adult ; Embryo Transfer ; Female ; Genetic Carrier Screening ; Genetic Testing ; Hemoglobins, Abnormal ; Humans ; Hydrops Fetalis ; diagnosis ; genetics ; prevention & control ; Male ; Minisatellite Repeats ; genetics ; Ovulation Induction ; methods ; Polymerase Chain Reaction ; Pregnancy ; Pregnancy Complications, Hematologic ; diagnosis ; genetics ; prevention & control ; Preimplantation Diagnosis ; Singapore ; Sperm Injections, Intracytoplasmic ; alpha-Globins ; genetics
2.First successful preimplantation genetic diagnosis in Singapore--avoidance of beta-thalassaemia major.
Christine YAP ; Arnold S C TAN ; Wen WANG ; Mui Nee LIM ; Samuel S CHONG
Annals of the Academy of Medicine, Singapore 2009;38(8):720-723
INTRODUCTIONWe report on the first successful preimplantation genetic diagnosis (PGD) in Singapore.
CLINICAL PICTUREA couple who are beta-thalassaemia carriers and have an affected daughter requested for PGD.
TREATMENTTwo cycles of PGD were performed on the couple. Beta-thalassaemia mutations were detected using a nested PCR and minisequencing strategy, and unaffected embryos were selected for transfer.
OUTCOMEA singleton pregnancy was achieved in the second PGD cycle, resulting in the birth of a healthy baby boy with carrier genotype.
CONCLUSIONSThis case report documents the first successful PGD in Singapore, involving a couple at-risk of transmitting beta-thalassaemia major.
Adult ; Female ; Fertilization in Vitro ; Humans ; Male ; Pregnancy ; Preimplantation Diagnosis ; Risk Factors ; Singapore ; beta-Thalassemia ; diagnosis ; genetics ; prevention & control
3.Garcinexanthone G, a Selective Butyrylcholinesterase Inhibitor from the Stem Bark of Garcinia atroviridis
Kooi Yeong KHAW ; Vikneswaran MURUGAIYAH ; Melati KHAIRUDDEAN ; Wen Nee TAN
Natural Product Sciences 2018;24(2):88-92
The present study was undertaken to investigate the isolated compounds from the stem bark of Garcinia atroviridis as potential cholinesterase inhibitors and the ligand-enzyme interactions of selected bioactive compounds in silico. The in vitro cholinesterase results showed that quercetin (3) was the most active AChE inhibitor (12.65 ± 1.57 µg/ml) while garcinexanthone G (6) was the most active BChE inhibitor (18.86 ± 2.41 µg/ml). It is noteworthy to note that compound 6 was a selective inhibitor with the selectivity index of 11.82. Molecular insight from docking interaction further substantiate that orientation of compound 6 in the catalytic site which enhanced its binding affinity as compared to other xanthones. The nature of protein-ligand interactions of compound 6 is mainly hydrogen bonding, and the hydroxyl group of compound 6 at C-10 is vital in BChE inhibition activity. Therefore, compound 6 is a notable lead for further drug design and development of BChE selective inhibitor.
Butyrylcholinesterase
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Catalytic Domain
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Cholinesterase Inhibitors
;
Cholinesterases
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Computer Simulation
;
Drug Design
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Garcinia
;
Hydrogen Bonding
;
In Vitro Techniques
;
Quercetin
;
Xanthones
4.Antimicrobial wound dressing film utilizing nano-cellulose and gelatin as drug delivery system for Garcinia mangostana L extract
Leong Chean Ring ; Tong Woei Yenn ; Suzana Wahidin ; Wen-Nee Tan ; Siti Zubaidah Binti Abdullah ; Nurul Aisyah Mohd Jamil ; Muhammad Sharir Abdul Rahman
Malaysian Journal of Microbiology 2019;15(5):373-378
Aims:
Diabetic patients with foot ulcer showed 150-fold increased risk of amputation, which is primarily caused by microbial infection. Silver ions are commonly incorporated into wound dressing to enhance the antimicrobial property. However, concerns have been expressed about the development of bacterial resistance to heavy metals. In this study, we extracted the nano-cellulose from medical cotton and reinforced with gelatin to develop a film for wound dressing.
Methodology and results:
Garcinia mangostana L pericarp extract was incorporated into the nano-cellulose film as antimicrobial finishing. The efficacy of the developed nano-cellulose film was evaluated on diabetic wound microorganisms. We observed cellulose nano crystals with an average length of 133.71 nm under transmission electron microscope. The developed film showed gradual release of the extract over a period of 48 h and no burst effect was observed. The film exhibited significant inhibitory activity on three Gram positive bacteria, three Gram negative and all filamentous fungi tested. On Hohenstein challenge test, all test microorganisms showed significant growth reduction, with the treatment of the film. We also noticed that the antimicrobial activity of the film sustained even after 20 washes.
Conclusion, significance and impact of study
Our results indicate that the G. mangostana L pericarp extract loaded nano-cellulose films exhibited significant inhibitory activity on diabetic wound microorganisms. The developed film can be potentially used to prevent foot ulcer infection among diabetic patients.
5.Bioprospecting of Endophytic Fungi as Promising Anti-MRSA Agents
Yee-Min WEI ; Joo-Shun TAN ; Hock-Wei TANG ; Woei-Yenn TONG ; Chean-Ring LEONG ; Wen-Nee TAN
Natural Product Sciences 2022;28(3):93-104
Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to the global healthcare system. Ineffective and resistance to antibiotic treatments have increased morbidity and mortality rates worldwide.New and effective antibiotics are needed to combat against bacterial resistance. Endophytic fungi are crucial reservoirs of novel bioactive metabolites. In particular, the secondary metabolites show promising therapeutic potential, notably, antibacterial. This review discussed the emerging potential of endophytic fungi as anti-MRSA agents. The ecological sources of endophytic fungi were discussed with the synthesis of bioactive metabolites.The mode of antibacterial actions was elucidated to give a better understanding of the mechanisms involved. This review may serve as an important reference for future discovery and developments of anti-MRSA agents from endophytic fungi.
6.Antimicrobial activity of Aspergillus sp. IBRL MP15 CCL, an endophytic fungus isolated from Swietenia macrophylla leaf against human pathogens
Chean Ring LEONG ; Adib Arifah Binti Mansur ; Syarifah Abdul RASHID ; Swee Ngim ANG ; Wen-Nee TAN ; Woei Yenn TONG ; Darah IBRAHIM
Malaysian Journal of Microbiology 2018;14(1):49-54
Aims: Endophytes are microorganisms residing in the living tissues of the host plant and may contribute to their hostplant by producing a plethora of bioactive compounds that provide survival value to the plant. This study aimed toevaluate the antimicrobial activity of Aspergillus sp. IBRL MP15 CCL, an endophytic fungus isolated from Swieteniamacrophylla leaf.Methodology and results: The antimicrobial activity was evaluated with disc diffusion and a colorimetric brothmicrodilution test against 15 organisms comprising of 4 Gram-positive bacteria and 4 Gram-negative bacteria, 4 fungiand 3 yeast. On disc diffusion assay, the fungal extract was shown to inhibit the growth of 7 test bacteria and 3 testyeast. The antibacterial activity was more pronounced with extract from fungal culture with host plant extractsupplementation with significantly larger inhibition zones on all susceptible test microorganisms. The minimal inhibitoryconcentration of the extract ranged from 250 to 4000 μg/mL indicating different level of susceptibility of the testedpathogens against the fungal extract. The killing kinetic study shows that antimicrobial activity of the fungal extract isconcentration dependent and it can act as bactericidal at higher concentration.Conclusion, significance and impact of study: The findings of this study suggest that Aspergillus sp. IBRL MP15CCL can be a promising source of antimicrobial agent to be further studied and developed
7.Antimicrobial Efficacy of Penicillium amestolkiae elv609 Extract Treated Cotton Fabric for Diabetic Wound Care.
Nur Amiera Syuhada Binti ROZMAN ; Nurhanis Syafiqah Binti Mohd Nor HAMIN ; Leong Chean RING ; Tan Wen NEE ; Mahfuzah Binti MUSTAPHA ; Tong Woei YENN
Mycobiology 2017;45(3):178-183
Diabetes mellitus is a chronic disorder which affects millions of population worldwide. Global estimates published in 2010 reported the world diabetic prevalence as 6.4%, affecting 285 million adults. Foot ulceration and wound infection are major forms of disabilities arising from diabetic diseases. This study was aimed to develop a natural antimicrobial finishing on medical grade textile that meets American Association of Textiles Chemists and Colorists (AATCC) standard. The textile samples were finished with the ethanolic extract of Penicillium amestolkiae elv609, an endophytic fungus isolated from Orthosiphon stamineus Benth (common name: cat's whiskers). Endophyte is defined as microorganism that reside in the living plant tissue, without causing apparent disease symptom to the host. The antimicrobial efficacy of the ethanolic extract of P. minioluteum was tested on clinical pathogens isolated from diabetic wound. The extract exhibited significant inhibitory activity against 4 bacteria and 1 yeast with the minimal inhibitory concentration ranged from 6.25 to 12.5 mg/mL. The results indicate different susceptibility levels of the test microorganism to the ethanolic extract. However, the killing activity of the extract was concentration-dependent. The finished medical textile showed excellent antimicrobial efficacy on AATCC test assays. All the microbial cultures treated with the textile sample displayed a growth reduction of 99.9% on Hoheinstein Challenge Test. The wash durability of the finished textile was found good even after 50 washes with commercial detergent. Besides, the gas chromatography mass spectrometry analysis showed that 6-octadecenoic acid and diethyl phthalate were the main bioactive constituents of the extract. In conclusion, the developed medical textile showed good antimicrobial efficacy on laboratory tests. This work can be extended to in vivo trials for developing healthcare textile products for antimicrobial applications.
Adult
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Bacteria
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Delivery of Health Care
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Detergents
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Diabetes Mellitus
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Ethanol
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Foot Ulcer
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Fungi
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Gas Chromatography-Mass Spectrometry
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Homicide
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Humans
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Orthosiphon
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Penicillium*
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Plants
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Prevalence
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Textiles
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Wound Infection
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Wounds and Injuries*
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Yeasts
8.Anthocyanins from Clitoria ternatea Attenuate Food-Borne Penicillium expansum and its Potential Application as Food Biopreservative.
Chean Ring LEONG ; Muhammad Afif KAMARUL AZIZI ; Md Abu TAHER ; Suzana WAHIDIN ; Kok Chang LEE ; Wen Nee TAN ; Woei Yenn TONG
Natural Product Sciences 2017;23(2):125-131
Clitoria ternatea or Commonly known blue pea, is a perennial climber crop native to Asian countries. The current study was aimed to evaluate the antimicrobial activity C. ternatea extract on food borne microorganisms and its antifungal effect on Penicillium expansum. The extract showed significant antimicrobial activity against 3 Gram positive bacteria, 2 Gram negative bacteria and 1 filamentous fungus on disc diffusion assay. The extract also showed good biocidal effect on all Gram positive bacteria tested and P. expansum. However, the kill curve analysis revealed that the fungicidal activity of the extract against P. expansum conidia was depend on the concentration of the extract and the time of exposure of the conidia to the extract. The scanning electron micrograph of the extract treated P. expansum culture showed alterations in the morphology of fungal hyphae. The germination of P. expansum conidia was completely inhibited and conidial development was totally suppressed by the extract, suggesting the possible mode of action of anthocyanin. Besides, the extract also exhibited 5.0-log suppression of microbial growth relative to control in the rice model. The results indicate the potential use of the C. ternatea anthocyanin as food biopreservative.
Anthocyanins*
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Asian Continental Ancestry Group
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Clitoria*
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Diffusion
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Fungi
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Germination
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Gram-Negative Bacteria
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Gram-Positive Bacteria
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Humans
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Hyphae
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Peas
;
Penicillium*
;
Spores, Fungal
10.Chemical compositions and in vitro antimicrobial activity of Cymbopogon nardus on food borne microorganisms
Wen-Nee Tan ; Woei Yenn Tong ; Chean Ring Leong ; Nor Faizzah Md Hanafiah ; Nur Sufina Ridzuan ; Nur Amiera Syuhada Rozman ; Sharifah Soplah Syed Abdullah
Malaysian Journal of Microbiology 2018;14(7):699-704
Aims:
Food borne infections are routinely observed and frequently reported. Cymbopogon nardus, or commonly known as citronella is a tropical plant widely used for aromatherapy and insect repellant. This study aimed to evaluate the phytochemical compositions of C. nardus ethanol extract and its antimicrobial activity on food borne microorganisms.
Methodology and results:
The plant materials were extracted with ethanol using maceration technique. The ethanol extract obtained was analysed using GC-MS and the most abundant compounds were 6-methyloctahydrocoumarin (31.5%) and 2,4-di-tert-butylphenol (28.7%). On Kirby Bauer assay, the extract showed wide spectrum inhibitory effect on one Gram-positive bacteria (Bacillus coagulans), two Gram-negative bacteria (Proteus mirabilis and Escherichia coli), and one yeast (Candida albicans). All the test microorganisms showed different susceptibility to the extract, where the minimal inhibitory concentrations were ranged from 63 to 250 μg/mL. The inhibitory effect of the extract was bactericidal. In addition, the time kill analysis of the extract exhibited inhibitory effect on P. mirabilis which was concentration-dependent. The C. nardus extract exhibited rapid bactericidal effect on P. mirabilis and lower bacterial counts were obtained with increased extract concentration. Besides, the extract did not exert significant toxicity effect to Artemia salina on brine shrimp lethality assay.
Conclusion, significance and impact of study
Therefore C. nardus can be a potential source of safe and effective antimicrobial agent to combat food borne infections.