MyMedR

Fulltext Meningioma--the Sarawak General Hospital experience

Wong SH, Chan SH

Med J Malaysia, 2002 Dec;57(4):467-73.

The aim of this study was to determine the factors for the large size of intracranial meningiomas at the time of presentation to the Sarawak General Hospital. The data was collected prospectively from 1/3/2000 to 28/2/2001. During this period a total of 57 cases of intracranial tumours were operated upon. Twenty of these cases (35%) were meningioma, making meningioma the most common intracranial tumour operated in the Neurosurgery service here with one to two cases operated per month. Headache was the most common symptom. The average duration of symptoms before the diagnosis was made was twenty-five months, the longest being fifteen years. The patients needed an average of seven visits prior to the diagnosis.

Asian population frequencies and haplotype distribution of killer cell immunoglobulin-like receptor (KIR) genes among Chinese, Malay, and Indian in Singapore

Lee YC, Chan SH, Ren EC

Immunogenetics, 2008 Nov;60(11):645-54.

PMID: 18668235 DOI: 10.1007/s00251-008-0321-3

Killer cell immunoglobulin-like receptors (KIR) gene frequencies have been shown to be distinctly different between populations and contribute to functional variation in the immune response. We have investigated KIR gene frequencies in 370 individuals representing three Asian populations in Singapore and report here the distribution of 14 KIR genes (2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) with two pseudogenes (2DP1, 3DP1) among Singapore Chinese (n = 210); Singapore Malay (n = 80), and Singapore Indian (n = 80). Four framework genes (KIR3DL3, 3DP1, 2DL4, 3DL2) and a nonframework pseudogene 2DP1 were detected in all samples while KIR2DS2, 2DL2, 2DL5, and 2DS5 had the greatest significant variation across the three populations. Fifteen significant linkage patterns, consistent with associations between genes of A and B haplotypes, were observed. Eighty-four distinct KIR profiles were determined in our populations, 38 of which had not been described in other populations. KIR haplotype studies were performed using nine Singapore Chinese families comprising 34 individuals. All genotypes could be resolved into corresponding pairs of existing haplotypes with eight distinct KIR genotypes and eight different haplotypes. The haplotype A2 with frequency of 63.9% was dominant in Singapore Chinese, comparable to that reported in Korean and Chinese Han. The A haplotypes predominate in Singapore Chinese, with ratio of A to B haplotypes of approximately 3:1. Comparison with KIR frequencies in other populations showed that Singapore Chinese shared similar distributions with Chinese Han, Japanese, and Korean; Singapore Indian was found to be comparable with North Indian Hindus while Singapore Malay resembled the Thai.

Intraoperative methylene blue sentinel lymph node mapping in colorectal cancer

Chan SH, Ng C, Looi LM

ANZ J Surg, 2008 Sep;78(9):775-9.

PMID: 18844907 DOI: 10.1111/j.1445-2197.2008.04648.x

Isosulfan blue is not available for clinical use in Malaysia. This study describes the use of methylene blue as an alternative to isosulfan blue in colorectal sentinel node mapping.

Fulltext Mixed lymphocyte culture (MLC) test and living related donor kidney transplantation

Suleiman AB, Mohd Zaher ZM, Chan SH, Awang H

Med J Malaysia, 1984 Mar;39(1):56-8.

PMID: 6239969

The MtC tests performed prospectively was correlated with graft survival in 73 living, related grafts. The MLC was expressed as the relative response (RR), and graft survival assessed at six months, one year and two years. The l-haplotype matched grafts with high RR had poorer graft survival at one and two years than those with low RR, but this difference was not statistically significant.

HLA and nasopharyngeal carcinoma in Malays

Chan SH, Chew CT, Prasad U, Wee GB, Srinivasan N, Kunaratnam N

Br. J. Cancer, 1985 Mar;51(3):389-92.

PMID: 3855643

HLA associations were observed in unrelated Malay patients with nasopharyngeal carcinoma (NPC). HLA-B18 was observed in 18/45 (40%) Malay NPC patients compared to 22/167 (13%) Malay normals (P = 0.0001; Pc = 0.0027, RR = 4.4). The frequency of HLA-B17, one of the antigens associated with Chinese NPC, was also increased among Malay NPC (13/45 29%) compared to controls (18/167 11%; P = 0.003, Pc = 0.07 RR = 3.4). Similar to the findings among Chinese NPC, the frequency of B17 was higher in early onset (less than or equal to 30 years) Malay NPC resulting in a higher relative risk (RR = 5.0).

Hepatitis B virus markers in prostitutes in Singapore

Goh CL, Kamarudin A, Chan SH, Rajan VS

Genitourin Med, 1985 Apr;61(2):127-9.

PMID: 3980022

The prevalence of hepatitis B virus markers in 121 men and 239 women prostitutes was studied. Of 33 (9.7%) with hepatitis B surface antigen (HBsAg), nine (27.3%) also had hepatitis Be antigen, which was more prevalent in men than women. Antibodies to HBsAg (anti-HBs) and to hepatitis B core antigen (anti-HBc) were found in about 71% of men and women prostitutes. Hepatitis B virus markers were more prevalent in men than in women prostitutes. Compared with other people, prostitutes had a significantly greater prevalence of hepatitis B virus markers. This study strongly suggested the importance of sexual transmission of infection with hepatitis B virus in a country where infection is endemic.

HLA and nasopharyngeal cancer

Simons MJ, Chan SH, Day NE, Wee GB, Shanmugaratnam K

Prog. Clin. Biol. Res., 1977;16:145-8.

PMID: 905319

Chiral liquid chromatography-mass spectrometry (LC-MS/MS) method development for the detection of salbutamol in urine samples

Chan SH, Lee W, Asmawi MZ, Tan SC

J Chromatogr B Analyt Technol Biomed Life Sci, 2016 Jul 01;1025:83-91.

PMID: 27232053 DOI: 10.1016/j.jchromb.2016.05.015

A sequential solid-phase extraction (SPE) method was developed and validated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the detection and quantification of salbutamol enantiomers in porcine urine. Porcine urine samples were hydrolysed with β-glucuronidase/arylsulfatase from Helix pomatia and then subjected to a double solid-phase extraction (SPE) first using the Abs-Elut Nexus SPE and then followed by the Bond Elut Phenylboronic Acid (PBA) SPE. The salbutamol enantiomers were separated using the Astec CHIROBIOTIC™ T HPLC column (3.0mm×100mm; 5μm) maintained at 15°C with a 15min isocratic run at a flow rate of 0.4mL/min. The mobile phase constituted of 5mM ammonium formate in methanol. Salbutamol and salbutamol-tert-butyl-d9 (internal standard, IS) was monitored and quantified with the multiple reaction monitoring (MRM) mode. The method showed good linearity for the range of 0.1-10ng/mL with limit of quantification at 0.3ng/mL. Analysis of the QC samples showed intra- and inter-assay precisions to be less than 5.04%, and recovery ranging from 83.82 to 102.33%.

Fulltext Bacterial contamination of hospital disinfectants

Keah KC, Jegathesan M, Tan SC, Chan SH, Chee OM, Cheong YM, et al.

Med J Malaysia, 1995 Dec;50(4):291-7.

PMID: 8668045

A study to determine contamination of diluted disinfectants at different points in preparation and use in 6 Malaysian hospitals was done using the in-use test. A growth of > or = 250 organisms/ml was taken as an indication of contamination. A total of 342 (7.9%) of the 4316 freshly diluted samples collected from disinfectant bottles in the pharmacy were found to be contaminated. The bacterial isolates obtained were Pseudomonas spp. (42.4%), Moraxella spp. (22.0%), Flavobacterium spp. (11.6%) and Enterobacter spp. (4.2%). Three hundred and sixty seven out of 2278 ward stock were contaminated. The isolates were Pseudomonas spp. (48.6%), Moraxella spp. (17.8%), Acinetobacter spp. (8.9%) and Flavobacterium spp. (7.0%). Of the 9265 disinfectants in-use, 1519 (16.4%) were contaminated. Among the organisms isolated were Pseudomonas spp. (44.3%), Bacillus spp. (13.0%), Enterobacter spp. (9.5%) and Acinetobacter spp. (7.3%). The results indicated a high level of contamination of diluted disinfectants prepared in the pharmacy, stored and used in the wards. This gave a high index of suspicion that recommendations for cleaning of disinfectant containers before refilling, handling of diluted stock solutions and using of disinfectants were not closely adhered to. Standard disinfection procedures outlined in the disinfection and sterilization policy by the Ministry of Health should therefore be followed.

Disinfection: gaps between recommended and actual practice

Keah KC, Jegathesan M, Tan SC, Chan SH, Chee OM, Cheong YM, et al.

Southeast Asian J. Trop. Med. Public Health, 1995 Dec;26(4):795-8.

PMID: 9139397

Basic practices on disinfection was surveyed in 6 hospitals using an observation and interview checklist. Two surveys were done, one pre-(first survey) and one post-intervention (second survey). The disinfection and sterilization policy of the Ministry of Health was not available in 66 (70.2%) and 12 (13%) of the units in the first and second survey respectively. In the second survey, staff in all the units washed disinfectant containers before refilling compared with 41.5% of the units in the first survey. Dilution of disinfectants not recommended was found to be used in the first survey. Storing cleaned and sterile items in disinfectants, using disinfectant as a substitute for sterilization of autoclavable items and not decontaminating spillages were some of the wrong practices observed. Considerable improvements were made in the second survey. Improper usage of disinfectants was also indicated by failure of the in-use test. Rate of failure of disinfectants in-use decreased from 11.6% in the first survey to 5.0% in the second survey. To ensure proper disinfection practices, a comprehensive training program on disinfection is required for nurses and attendants.

Fulltext An evaluation of knowledge and awareness of disinfection and sterilization among health care workers

Keah KC, Jegathesan M, Tan SC, Chan SH, Che OM, Cheong YM, et al.

Southeast Asian J. Trop. Med. Public Health, 1995 Mar;26(1):51-6.

PMID: 8525420

Awareness of the disinfection and sterilization policy among hospital staff and their knowledge in basic principles and methods of disinfection and sterilization were studied before and after intervention using a self-administered questionnaire. Survey results showed that awareness (56.2%) before intervention was unsatisfactory. The nurses were more aware of the policy than other groups of medical personnel. Those unaware of the policy perform duties from memory or verbal instructions. A significant increase in awareness to 73.3% was observed after intervention (p < 0.05). Knowledge on methods of decontamination, disinfection and sterilization of equipment varies widely from 28.8% to 90.1%. 23.1% were unaware of the temperature used for sterilization while 72.4% did not know how containers of disinfectant should be refill. Only 14.7% knew the recommended method for washing containers. With education improvement was observed. The average knowledge improved from 44.4% to 57.3%. Our results indicated that continuous in-service education is needed to improve, supplement and update knowledge in this field after basic training. In addition orientation programs for new staff should also be aimed at creating awareness and providing information on guidelines and policies related to their duties.

HLA and filariasis in Sri Lankans and Indians

Chan SH, Dissanayake S, Mak JW, Ismail MM, Wee GB, Srinivasan N, et al.

Southeast Asian J. Trop. Med. Public Health, 1984 Sep;15(3):281-6.

PMID: 6523169

Similar HLA association was found in patients with elephantiasis in Sri Lankans and Southern Indians. HLA-B15 was observed in 13/44 (30%) Sri Lankan patients with elephantiasis compared to 1/27 (4%) Sri Lankan controls (p = .0058; RR = 10.9) and in 5/8 (28%) Southern Indian elephantiasis compared to 10/101 (10%) Southern Indian controls (p = 0.04; RR = 3.5). In combining the data, the significance of the difference of the frequency of B15 between patients with elephantiasis and controls was even more marked (p = 0.00045; corrected p = 0.012; RR = 4.4).

Fulltext Molecular Systematics of the Firefly Genus Luciola (Coleoptera: Lampyridae: Luciolinae) with the Description of a New Species from Singapore

Jusoh WFA, Ballantyne L, Chan SH, Wong TW, Yeo D, Nada B, et al.

Animals (Basel), 2021 Mar 04;11(3).

PMID: 33806564 DOI: 10.3390/ani11030687

The firefly genus Luciola sensu McDermott contains 282 species that are distributed across major parts of Asia, Europe, Africa, Australia, and the Pacific islands. Due to phenotypic similarities, species identification using external morphological characters can be unreliable for this group. Consequently, decades of piecemeal taxonomic treatments have resulted in numerous erroneous and contentious classifications. Furthermore, our understanding of the group's evolutionary history is limited due to the lack of a robust phylogenetic framework that has also impeded efforts to stabilize its taxonomy. Here, we constructed molecular phylogenies of Luciola and its allies based on combined mitogenomes and Cytochrome c oxidase subunit 1 (COX1) sequences including a newly sequenced mitogenome of an unidentified taxon from Singapore. Our results showed that this taxon represents a distinct and hitherto undescribed evolutionary lineage that forms a clade with L. filiformis from Japan and L. curtithorax from China. Additionally, the Singaporean lineage can be differentiated from other congeners through several external and internal diagnostic morphological characters, and is thus described herein as a new species. Our phylogeny also strongly supported the paraphyly of Luciola with regard to L. cruciata and L. owadai, which were inferred to be more closely related to the genus Aquatica as opposed to other members of Luciola sensu stricto. The genus Hotaria was inferred as a derived clade within Luciola (sister to L. italica), supporting its status as a subgenus of Luciola instead of a distinct genus. This is the first time since 1909 that a new species of luminous firefly has been discovered in Singapore, highlighting the need for continued biodiversity research, even in small, well-studied and highly developed countries, such as Singapore.

HLA antigens in three common populations in South East Asia--Chinese, Malay and Filipino

Chan SH, Wee GB, Srinivasan N, Glen SP, Cheng P, Vengadasalam D, et al.

Tissue Antigens, 1979 May;13(5):361-8.

PMID: 91213

Fulltext Potent α-glucosidase and α-amylase inhibitory activities of standardized 50% ethanolic extracts and sinensetin from Orthosiphon stamineus Benth as anti-diabetic mechanism

Mohamed EA, Siddiqui MJ, Ang LF, Sadikun A, Chan SH, Tan SC, et al.

BMC Complement Altern Med, 2012;12:176.

PMID: 23039079 DOI: 10.1186/1472-6882-12-176

In the present study, we tested a 50% ethanolic extract of Orthosiphon stamineus plants and its isolated bioactive compound with respect to their α-glucosidase and α-amylase inhibitory activities.

Nasopharyngeal carcinoma and histocompatibility antigens

Simons MJ, Chan SH, Wee GB, Shanmugaratnam K, Goh EH, Ho JH, et al.

IARC Sci Publ, 1978.

PMID: 730194

New data are presented concerning the relationship between NPC and HLA antigens among Chinese. When attention is confined to newly diagnosed cases, it can be shown that, apart from the increased risk associated with the joint occurrence of A2 and B-Sin 2, there is also an increased risk associated with BW17 and a decrease in risk associated with A11. Among long-term survivors, however, BW17 is appreciably decreased, whereas A2 in the absence of B-Sin 2 or BW17 is increased. Among Malays, a non-Chinese group, there is an excess among NPC patients of a locus A blank, a blank which is probably associated with the AW19 complex.

Fulltext Clinical practice with steroid therapy for Duchenne muscular dystrophy: An expert survey in Asia and Oceania

Takeuchi F, Nakamura H, Yonemoto N, Komaki H, Rosales RL, Kornberg AJ, et al.

Brain Dev, 2020 Mar;42(3):277-288.

PMID: 31980267 DOI: 10.1016/j.braindev.2019.12.005

BACKGROUND: Several studies on clinical practice for Duchenne muscular dystrophy (DMD) have been conducted in Western countries. However, there have been only a few similar studies in Asia and Oceania. Here, we investigate the steroid therapy-related clinical practice for DMD among the local experts. In 2015, we conducted a DMD expert survey in Asia and Oceania to acquire information regarding patients with DMD and to assess current clinical practice with the cooperation of Asian and Oceanian Myology Centre, a neuromuscular disease research network.

RESULTS: We obtained survey responses from 87 out of 148 clinicians (62%) from 13 countries and regions. In China, 1385 DMD patients were followed-up by 5 respondent neurologists, and 84% were between 0 and 9 years of age (15% were 10-19 years, 1% > 19 years). While in Japan, 1032 patients were followed-up by 20 clinicians, and the age distribution was similar between the 3 groups (27% were 0-9 years, 35% were 10-19 years, 38% were >19 years). Most respondent clinicians (91%) were aware of DMD standard of care recommendations. Daily prednisolone/prednisone administration was used most frequently at initiation (N = 45, 64%). Inconsistent opinion on steroid therapy after loss of ambulation and medication for bone protection was observed.

CONCLUSIONS: Rare disease research infrastructures have been underdeveloped in many of Asian and Oceanian countries. In this situation, our results show the snapshots of current medical situation and clinical practice in DMD. For further epidemiological studies, expansion of DMD registries is necessary.

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