MyMedR

Indudharan R, Ahamad M, Ho TM, Salim R, Htun YN

Ann Trop Med Parasitol, 1999 Mar;93(2):163-7.

Accidental entry of insects and other arthropods is a common aetiology of aural foreign bodies (FB) presenting to accident and emergency departments. A retrospective study revealed that the FB in almost half (148) of 348 cases of aural FB investigated at the Universiti Sains Malaysia Hospital was an arthropod. The most common arthropod encountered was the cockroach, followed by a cattle tick. The high prevalence of tick infestation of the human ear canal (i.e. human otoacariasis) currently appears to be unique to the Malaysian state of Kelantan. The presentation of patients with intra-aural ticks, the methods used to remove the ticks, the complications encountered, and recommendations for an appropriate course of action in such cases are discussed.

Fulltext The first graduates in 1910

Cheah JS, Ho TM, Ng BY

Ann Acad Med Singap, 2005 Jul;34(6):19C-24C.

PMID: 16010376

The Medical School in Singapore was founded on 3 July 1905 and named the Straits and Federated Malay States Government Medical School. There were 23 students in the first enrollment; 16 students attended the full course, while 7 attended a 2-year course for hospital assistants. The pioneer group of 7 that graduated in May 1910 (the Magnificent Seven) consisted of Drs Chen Su Lan, Edwin Williborod deCruz, and John Gnanapragasam from Singapore; Drs Willie Carnegie and Mark W Chill from Penang; Dr SR Krishnan from Seramban and Dr John Scott Lee from Ipoh. In December 1910, a further 6 students graduated. Of this first batch of 13 graduates in 1910, we describe the careers of 6; no records exist of the remaining 7.

Seasonal prevalence of air-borne pollen and spores in Kuala Lumpur, Malaysia

Ho TM, Tan BH, Ismail S, Bujang MK

Asian Pac J Allergy Immunol, 1995 Jun;13(1):17-22.

PMID: 7488339

Aerosampling using Rotorod samplers was conducted in the Institute for Medical Research, Kuala Lumpur, Malaysia, from December 1991 to November 1993. Samples were collected twice a week between 10.00 hours to 12.00 hours. Rods were stained and examined microscopically. A total of 8 and 20 types of pollens and mold spores were collected, respectively. More mold spores were collected than pollens. Grass pollen constituted more than 40 percent of total pollen counts. Gramineae pollen counts peaked in March and September. The most abundant mold spore was Cladosporium followed by Rust, Nigrospora, Curvularia and Smut. Cladosporium counts peaked in February and August. Rust counts peaked in June and December whereas counts for Nigrospora peaked in February and October. Highest counts of Smut were recorded in March and October. Curvularia counts peaked in January, June and September.

Prevalence of allergy to some inhalants among rhinitis patients in Malaysia

Ho TM, Murad S, Kesavapillai R, Singaram SP

Asian Pac J Allergy Immunol, 1995 Jun;13(1):11-6.

PMID: 7488338

This study was conducted to determine the seasonal prevalence of allergies to house dust, D. pteronyssinus, D. farinae, cat fur, dog hair, mixed moulds, mixed grass pollens and American cockroach. A total of 314 patients with clinically suspected allergic rhinitis was examined by prick test using commercial preparations of the above allergens. Total serum IgE of the patients was determined by a Sandwich ELISA. Ninety-six percent of the patients tested positive to more than one allergen. Most were positive to a combination of 4 allergens. More than 70% of the patients were positive to house dust, D. pteronyssinus, D. farinae and cat fur. Analysis indicates that for an individual who tests positive for house dust, there is a very high risk of the person being allergic to the dust mites and cat fur too. Most of the allergens had 2 peak period of high positive PT rates; mixed moulds and mixed grass pollens had 3 peaks. There was significant positive correlation between the monthly positive PT rates against mixed moulds and mixed grass pollens with maximum daily mean temperature and mean temperature at 14.00 hours.

Evaluation of the MAST CLA allergy system for diagnosis of allergies to house dust mites and cats

Ho TM, DeBruynne J, Ahamad M, Darussamin H

Asian Pac J Allergy Immunol, 1997 Sep;15(3):123-6.

PMID: 9438543

The MAST CLA system was evaluated against skin prick test (SPT) for diagnosis of allergies to house dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae) and cats. Forty three asthmatic children were examined by SPT and MAST CLA. Chi-square analysis indicated significant association between SPT and MAST CLA results for the house dust mites but not for cats. The sensitivities of MAST CLA for house dust mites and cats were 100 and 25% respectively; specificities were all less than 50%. The efficiency of MAST CLA for detection of allergy to the house dust mites was 88% and 44% for cats. A significant linear correlation was found between SPT wheal size and MAST CLA grade for D. farinae but not for D. pteronyssinus and cats. It is concluded that the MAST CLA allergy system can be used to supplement SPT for diagnosis of allergies to house dust mites but not to cats.

Development of an enzyme-linked immunosorbent assay for detection of IgE antibodies specific to Dermatophagoides pteronyssinus

Ho TM, Yit YH, Husain M

Asian Pac J Allergy Immunol, 1988 Dec;6(2):103-6.

PMID: 3146256

Allergy to Dermatophagoides pteronyssinus was determined in 61 rhinitis patients using prick test (PT), enzyme-immunoassay (EIA) and enzyme-linked immunosorbent assay (ELISA). A total of 43 patients tested positive with PT. Forty six patients were positive when tested with EIA and ELISA. With PT as standard test, EIA was found to have 83.7% sensitivity and 44.4% specificity; ELISA had 81.4% sensitivity and 38.9% specificity. There was a linear relationship between absorbance values obtained by EIA and ELISA. The performance time was 8 hours, 24 hours and 30 minutes for ELISA, EIA and PT respectively. The cost per test for ELISA, EIA and PT was US$ 0.20, US$ 5.20 and US$ 0.14 respectively. It was concluded that ELISA was more cost-effective than EIA should be used to supplement PT for a more complete diagnosis of allergy.

Fulltext Effect of germicidal UV-C light(254 nm) on eggs and adult of house dustmites, Dermatophagoides pteronyssinus and Dermatophagoides farinae (Astigmata: Pyroglyhidae)

Lah EF, Musa RN, Ho TM

Asian Pac J Trop Biomed, 2012 Sep;2(9):679-83.

PMID: 23569994 DOI: 10.1016/S2221-1691(12)60209-3

To examined the immediate and 24 hours post- irradiation germicidal effects of UV-C lamp on eggs and adults of house dust mites Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae).

Fulltext Effect of a commercial air ionizer on dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae (Acari: Pyroglyphidae) in the laboratory

Abidin SZ, Ho TM

Asian Pac J Trop Biomed, 2012 Feb;2(2):156-8.

PMID: 23569888 DOI: 10.1016/S2221-1691(11)60212-8

To investigate the short and long term efficacy of a commercial air ionizer in killing Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae) mites.

Fulltext Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites

Hanifah AL, Awang SH, Ho TM, Abidin SZ, Omar MH

Asian Pac J Trop Biomed, 2011 Oct;1(5):365-9.

PMID: 23569794 DOI: 10.1016/S2221-1691(11)60081-6

To examine the acaricidal effects of the essential oil of Cymbopogon citratus leaf extract (lemongrass) and ethanolic Azadirachta indica leaf extract (neem) against house dust mites Dermatophagoides farinae (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus).

Fulltext Acarine ectoparasites of Panti Forest Reserve in Johore, Malaysia

Mariana A, Mohd KB, Halimaton I, Suhaili ZA, Shahrul-Anuar MS, Nor ZM, et al.

Asian Pac J Trop Biomed, 2011 Jan;1(1):1-5.

PMID: 23569714 DOI: 10.1016/S2221-1691(11)60057-9

To identify the presence of acarine ectoparasites and determine whether there is any potential public health risk in Panti Forest Reserve, Johore, Malaysia.

Fulltext Acariasis on pet Burmese python, Python molurus bivittatus in Malaysia

Mariana A, Vellayan S, Halimaton I, Ho TM

Asian Pac J Trop Med, 2011 Mar;4(3):227-8.

PMID: 21771459 DOI: 10.1016/S1995-7645(11)60075-8

OBJECTIVE: To identify the acari present on pet Burmese pythons in Malaysia and to determine whether there is any potential public health risk related to handling of the snakes.

METHODS: Two sub-adult Burmese pythons kept as pets for a period of about 6 to 7 months by different owners, were brought to an exotic animal practice for treatment. On a complete medical examination, some ticks and mites (acari) were detected beneath the dorsal and ventral scales along body length of the snakes. Ticks were directly identified and mites were mounted prior to identification.

RESULTS: A total of 12 ticks represented by 3 males, 2 females and 7 nymphal stages of Rhipicephalus sanguineus (R. sanguineus) were extracted from the first python while the other one was with 25 female Ophionyssus natricis (O. natricis) mesostigmatid mites. Only adult female mites were found. These mites are common ectoparasites of Burmese pythons.

CONCLUSIONS: Both the acarine species found on the Burmese pythons are known vectors of pathogens. This is the first record that R. sanguineus has been reported from a pet Burmese python in Malaysia.

Expression of recombinant proteins of Orientia tsutsugamushi and their applications in the serodiagnosis of scrub typhus

Tay ST, Rohani MY, Ho TM, Devi S

Diagn Microbiol Infect Dis, 2002 Oct;44(2):137-42.

PMID: 12458119

In this study, recombinant proteins that encompassed the AD I-AD III regions of 56 kDa immunodominant gene of 2 Orientia tsutsugamushi (OT) serotypes; Gilliam and TA763 were expressed in Escherichia coli. Both recombinant proteins exhibited serologic cross-reactivity with the rabbit antisera against various OT serotypes, as evaluated by enzyme-linked immunosorbent assay (ELISA), but not against other rickettsial species, including Rickettsia typhi, R. prowazekii and TT118 SFG rickettsiae. The feasibility of using the recombinant proteins as a diagnostic reagent was further evaluated by ELISA using sera from blood donors and scrub typhus patients. The results suggested a higher affinity of the antihuman IgM than IgG with both recombinant proteins. The IgM ELISA findings were agreeable with the results of indirect immunoperoxidase (IIP) assay especially with sera of high antibody (1:1600). However, more than one antigen are probably needed for development of an effective assay for serodiagnosis of scrub typhus in endemic areas.

Molecular identification of house dust mites and storage mites

Wong SF, Chong AL, Mak JW, Tan J, Ling SJ, Ho TM

Exp Appl Acarol, 2011 Oct;55(2):123-33.

PMID: 21468750 DOI: 10.1007/s10493-011-9460-6

Mites are known causes of allergic diseases. Currently, identification of mites based on morphology is difficult if only one mite is isolated from a (dust) sample, or when only one gender is found, or when the specimen is not intact especially with the loss of the legs. The purpose of this study was to use polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the ITS2 gene, to complement the morphological data for the identification of mites to the species level. For this, six species were cultured: Dermatophagoides pteronyssinus, D. farinae, Blomia tropicalis, Tyrophagus putrescentiae, Aleuroglyphus ovatus and Glycycometus malaysiensis. Genomic DNA of the mites was extracted, quantified, amplified and digested individually with restriction enzymes. Hinf I and Ple I differentiated the restriction patterns of D. pteronyssinus and D. farinae. Bfa I and Alu I enzymes differentiated B. tropicalis and G. malaysiensis. Ple I enzyme was useful for the differentiation between T. putrescentiae and A. ovatus. Bfa I was useful for the differentiation of G. malaysiensis from the rest of the species. In conclusion, different species of mites can be differentiated using PCR-RFLP of ITS2 region. With the established PCR-RFLP method in this study, identification of these mites to the species level is possible even if complete and intact adult specimens of both sexes are not available. As no study to date has reported PCR-RFLP method for the identification of domestic mites, the established method should be validated for the identification of other species of mites that were not included in this study.

Phoretic association between Macrocheles muscaedomesticae (Acari: Macrochelidae) and flies inhabiting poultry manure in Peninsular Malaysia

Ho TM

Exp Appl Acarol, 1990 Nov;10(1):61-8.

PMID: 2279455

The phoretic association between Macrocheles muscaedomesticae and flies that inhabited poultry manure in a poultry farm in Sungai Buloh, Selangor, Malaysia was studied. The effects of temperature, relative humidity and fly abundance on phoretic rates also were investigated. The most abundant fly species found was Musca domestica; Musca sorbens, Chrysomyia megacephala and Ophyra chalcogaster were present in relatively large numbers. Representatives of ten families of mites were found on collected Mu. domestica. The most common mite was Ma. muscaedomesticae (Macrochelidae), found on all four species of flies mentioned above. The highest infestation (2.0%) occurred on O. chalcogaster but Mu. domestica had the highest average number infested (5.7). The ventral part of the housefly's abdomen was the most common site of mite attachment. Usually only one mite was found attached per fly. The highest phoretic rate recorded was 64.4 Ma. muscaedomesticae per 1000 Mu. domestica. There was no correlation between phoretic rates and Ma. muscaedomesticae abundance, nor was relative humidity a factor. However, a positive correlation was recorded in this host species between phoretic rates and temperature.

Setting an objective

Ho TM

Family Physician, 1989;1(3):5.

Our update series

Ho TM

Family Physician, 1991;3(3):4.

Fulltext The journal as cottage industry

Ho TM

Family Physician, 1992;4(2&3):4.

A titan in our midst - a tribute to Dato' Dr A. W. E. Moreira

Ho TM

Family Practitioner, 1981;4(2):48-49.