MyMedR

Fulltext Identification of potential vectors of Dirofilaria immitis and Brugia pahangi (Spirurida: Filariidae): First observation of infective third-stage larva of B. pahangi in Culex quinquefasciatus (Diptera: Culicidae)

Vinnie-Siow WY, Low VL, Tan TK, Wong ML, Leong CS, Ahmad NW, et al.

Pathog Glob Health, 2022 Sep;116(6):356-364.

PMID: 35287548 DOI: 10.1080/20477724.2022.2035624

Information on the mosquito species that transmit canine filariosis is scanty. Hence, an experimental study was conducted to identify the potential vectors responsible for the transmission of D. immitis Leidy and B. pahangi Buckley & Edeson. A total of 367 mosquitoes belonging to six species containing both laboratory and field strains (i.e. Aedes togoi Theobald, Aedes aegypti Linnaeus, Aedes albopictus Skuse, Culex quinquefasciatus Say, Culex vishnui Theobald and Anopheles dirus Peyton & Harrison) were used in this study. All mosquitoes were artificially fed on either D. immitis or B. pahangi microfilariae (mfs) infected blood by using the Hemotek™ membrane feeding system. Out of 367 mosquitoes, 228 (64.9%) were fully engorged. After feeding on D. immitis (20%) and B. pahangi (33%) mfs positive blood, the mortality rates for Cx. quinquefasciatus were found to be slightly lower than that of other species of mosquitoes. On the other hand, majority of An. dirus were found to be incapable to withstand the infection of mfs as the mortality rates were relatively high (D. immitis = 71.4%; B. pahangi = 100.0%). Brugia pahangi was detected in Ae. togoi and Cx. quinquefasciatus with infection rates of 50% and 25%, respectively. Aedes togoi was the only species infected with D. immitis with an infection rate of 69%. Our results showed that Ae. togoi was an excellent experimental vector for both D. immitis and B. pahangi. This study also documented the observation of B. pahangi, for the first time in the head region of Cx. quinquefasciatus under a laboratory setting.

Role of interceptive orthodontics in early mixed dentition

Wong ML, Che Fatimah Awang, Ng LK, Norlian D, Rashidah Dato Burhanudin, Gere MJ

Singapore Dent J, 2004 Dec;26(1):10-4.

PMID: 15736836

Early orthodontic interventions are often initiated in the developing dentition to promote favourable developmental changes and remove or suppress those that are unfavourable. Early interceptive orthodontics can eliminate or reduce the severity of a developing malocclusion, the complexity of orthodontic treatment, overall treatment time and cost. It also improves self-esteem in the subjects and parental satisfaction. Early detection and appropriate referral of cases requiring interceptive orthodontics are important. However, lack of awareness among school children, parents and primary-care personnel (dental nurses and dental officers) may result in patients not being referred for timely interceptive intervention. This article presents a general view of the scope of interceptive orthodontics that can be carried out in early mixed dentition, i.e. when the permanent incisors and molars are erupting into the oral cavity.

Fulltext Social capital and chemsex initiation in young gay, bisexual, and other men who have sex with men: the pink carpet Y cohort study

Tan RKJ, O'Hara CA, Koh WL, Le D, Tan A, Tyler A, et al.

Subst Abuse Treat Prev Policy, 2021 02 19;16(1):18.

PMID: 33608005 DOI: 10.1186/s13011-021-00353-2

BACKGROUND: Young gay, bisexual, and other men who have sex with men (YMSM) are especially vulnerable to the risks associated with sexualized substance use, or 'chemsex'. Engaging in chemsex established as a major risk factor for Human Immunodeficiency Virus (HIV) acquisition, and is thus a public health issue of increasing urgency. This paper attempts to explore the association between measures of social capital and patterns of sexualized substance use among a sample of YMSM in Singapore.

METHODS: Results of this study were derived from baseline data of the Pink Carpet Y Cohort Study in Singapore, comprising a sample of 570 HIV-negative YMSM aged 18 to 25 years old. Latent class analysis was employed to identify classes with similar patterns of sexualized substance use, and multinomial logistic regression was employed to examine associations between class membership and proxy measures of social capital, including age of sexual debut, bonding and bridging social capital, connectedness to the lesbian, gay, bisexual and transgender community, and outness.

RESULTS: Latent class analysis revealed three classes of YMSM based on their histories of sexualized substance use, which we labelled as 'alcohol', 'poppers', and 'chemsex'. Multivariable analyses revealed that participants who were older (aOR = 1.19, p = 0.002) and who identified as gay (aOR = 2.43, p = 0.002) were more likely to be in the poppers class compared to the alcohol class. Participants with a later age of sexual debut were increasingly less likely to be in the poppers (aOR = 0.93, p = 0.039) and chemsex classes (aOR = 0.85, p = 0.018), compared to the alcohol class.

CONCLUSIONS: Varying measures of social capital such as an earlier age of exposure to sexual networks may predispose YMSM to greater opportunities for sexualized substance use. Future interventions should target YMSM who become sexually active at an earlier age to reduce the risks associated with sexualized substance use.

Hepatocellular damage due to methyldopa

Wong ML

Med J Malaya, 1971 Mar;25(3):218-9.

PMID: 4253251

Fulltext Smoking behaviour, knowledge and opinion of medical students

Wong ML, Chen PC

Med J Malaysia, 1989 Dec;44(4):317-23.

PMID: 2520041

On the basis of a questionnaire on smoking behaviour, knowledge and attitudes administered to medical students in the University of Malaya in July 1987, the prevalence of smoking was found to be low (10%) among medical students. Smokers and non-smokers were equally well informed about common smoking complications. Most students, irrespective of smoking status, felt that they would as future doctors, often advise sick smokers against smoking. In contrast, less than half would do so for healthy smokers who do not themselves raise the question of smoking. The students' personal smoking behaviour also influenced their view of their professional role. Appropriate values, attitudes and a preventive approach towards smoking need to be further developed in the medical students' thinking and behaviour.

Lung function reference values in Singaporean children aged 6-18 years

Connett GJ, Quak SH, Wong ML, Teo J, Lee BW

Thorax, 1994 Sep;49(9):901-5.

PMID: 7940431

A study was undertaken to produce reference values of lung function in Chinese children and a means of calculating adjusted standard deviation scores of lung function for Malay and Indian ethnic groups.

Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes

Joanne S, Vythilingam I, Teoh BT, Leong CS, Tan KK, Wong ML, et al.

Trop Med Int Health, 2017 09;22(9):1154-1165.

PMID: 28653334 DOI: 10.1111/tmi.12918

OBJECTIVE: To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes.

METHODS: Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries.

RESULTS: Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4.

CONCLUSION: Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status.

Fulltext Self-reliance in health among village women

Wong ML, Chen PCY

World Health Forum, 1991;12(1):43-8.

PMID: 1859597

Fulltext Local human movement patterns and land use impact exposure to zoonotic malaria in Malaysian Borneo

Fornace KM, Alexander N, Abidin TR, Brock PM, Chua TH, Vythilingam I, et al.

Elife, 2019 10 22;8.

PMID: 31638575 DOI: 10.7554/eLife.47602

Human movement into insect vector and wildlife reservoir habitats determines zoonotic disease risks; however, few data are available to quantify the impact of land use on pathogen transmission. Here, we utilise GPS tracking devices and novel applications of ecological methods to develop fine-scale models of human space use relative to land cover to assess exposure to the zoonotic malaria Plasmodium knowlesi in Malaysian Borneo. Combining data with spatially explicit models of mosquito biting rates, we demonstrate the role of individual heterogeneities in local space use in disease exposure. At a community level, our data indicate that areas close to both secondary forest and houses have the highest probability of human P. knowlesi exposure, providing quantitative evidence for the importance of ecotones. Despite higher biting rates in forests, incorporating human movement and space use into exposure estimates illustrates the importance of intensified interactions between pathogens, insect vectors and people around habitat edges.

Displaying publications 21 - 29 of 29 in total