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- PublicationDistribution and morphological measurements of wild and urban rodents from four habitats in the States of Selangor and Negeri Sembilan, Malaysia(2013)A total of 204 rodents comprising of 14 species were identified from four different habitats namely urban, forest, paddy field and coastal. The Gombak forest reserve habitat was found to be ideal for the survival of 11 different rodent species. Maxomys rajah, Leopoldamys sabanus and Sundamys muelleri were the predominant rodent species distributed in the Gombak forest. Rattus ratus diardii was found mainly in the urban, paddy field and coastal habitat (67.1%). Morphological measurements of the rodents trapped from the four habitats did not show any major changes.
- PublicationSusceptibility of Aedes albopictus Skuse (Diptera: Culicidae) to permethrin in Kuala Lumpur, Malaysia(2013)Background: Insects control using insecticides is used extensively and intensively in vector control programs in many countries including Malaysia. Because of this, mosquito species have been found to develop various levels of resistance towards these insecticides, leading to failure in vector control activities. Objectives: We determined permethrin resistance status in laboratory susceptible, permethrin-selected, and field strains of Aedes albopictus. Methods: The susceptibility status of laboratory susceptible strain, permethrin-selected strain, and four field strains of Aedes albopictus collected from Kuala Lumpur were determined using three standard laboratory tests, WHO larval bioassay, WHO adult mosquito bioassay, and microassay of mixed function oxidases (MFOs). Results: The LC50 values of permethrin-selected strain and field strains obtained from the WHO larval bioassay were almost two times higher (0.38-0.44 mg/L) than the LC50 value of the laboratory strain (0.20 mg/L). In the WHO adult bioassay, the susceptibility of permethrin-exposed of both permethrin-selected strain, and field strains (LT50 = 19.39 to 20.65 min) were reduced for 1.31 to 1.72 times after been exposed to the synergist, piperonyl butoxide (PBO) prior to permethrin. Complete mortalities were also recorded in both permethrin-exposed and PBO + permethrin-exposed Ae. albopictus of all strains, twenty-four hours post-exposure. For the MFOs enzyme microassay, a significant difference (p <0.05) in the mean absorbance of elevated oxidase activity at 630 nm was observed between all strains of both the non-exposed and PBO-exposed Ae. albopictus. Strong and significant positive correlations were also observed between LT50 values of permethrin-exposed and PBO + permethrinexposed with oxidase level in Ae. albopictus tested (r = 0.943; p <0.05). Conclusion: These results indicate the association of oxidase activity with permethrin resistance development in Ae. albopictus.
- PublicationDevelopment of permethrin resistance in Culex quinquefasciatus Say in Kuala Lumpur, Malaysia(2013)The resistance status towards permethrin among the laboratory strain, the permethrin-selected strain and four field strains of Culex quinquefasciatus collected in Kuala Lumpur, Malaysia was determined using three standard laboratory methods: WHO larval bioassay, WHO adult bioassay and biochemical microplate assay. Cx. quinquefasciatus permethrin-selected strain larvae were the least susceptible to permethrin with a resistance ratio of 47.28-folds, whereas all field strain larvae of the same species were tolerant to permethrin with resistance ratios of more than 3-folds. In contrast, in adult stage, the permethrin exposed permethrin-selected strain (resistance ratio = 1.27) was found to be more susceptible to permethrin than all permethrin-exposed field strains (resistance ratios = 2.23–2.48). Complete mortalities for all strains of Cx. quinquefasciatus adults proved the effectiveness of the synergist; piperonyl butoxide (PBO). For the biochemical microplate assay, the reduction of the mean optical density of elevated oxidase activity of three field strains upon exposure to PBO confirmed the association between oxidase activity and permethrin tolerance. On the other hand, irregular patterns of the mean optical density of elevated oxidase activity in the laboratory strain, permethrin-selected strain and Jalan Fletcher strain illustrated the gene variation within these mosquito colonies as well as the involvement of other enzyme activities in the permethrin resistance occurred.
- PublicationOral Ingestion of Transgenic RIDL Ae. aegypti Larvae Has No Negative Effect on Two Predator Toxorhynchites Species(2013)Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered 'sterile' homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment.
- PublicationEvaluation of the Association of Plasma Pentraxin 3 Levels with Type 2 Diabetes and Diabetic Nephropathy in a Malay Population(2013)Recent reports have demonstrated that elevated plasma long pentraxin 3 (PTX3) levels are associated with cardiovascular and chronic kidney diseases. In the current study, we investigated the plasma PTX3 levels in 296 Malay subjects including the subjects with normal glucose tolerance (NGT) and type 2 diabetes (T2DM) patients with or without DN by using an enzyme-linked immune-sorbent assay. Results showed that in males, plasma PTX3 levels in T2DM patients without DN were lower than that in the subjects with NGT (2.78 versus 3.98 ng/mL;P=0.021). Plasma PTX3 levels in T2DM patients with DN were decreased compared to the patients without DN (1.63 versus 2.78 ng/mL;P=0.013). In females, however, no significant alteration of plasma PTX3 levels among NGT subjects and T2DM patients with and without DN was detected. Furthermore, an inverse correlation between PTX3 and body mass index was found in male subjects with NGT (P=0.012;r=-0.390), but not in male T2DM patients, neither in all females. The current study provided the first evidence that decreased plasma PTX3 levels are associated with T2DM and DN in Malay men and also suggested that PTX3 may have different effects in DN and chronic kidney diseases.
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- PublicationEffectiveness of a community-based intervention for weight loss on cardiometabolic risk factors among overweight and obese women in a low socio-economic urban community: findings of the MyBFF@home(2018)Background: The effectiveness of lifestyle intervention for weight loss on cardiometabolic risk factors among overweight and obese individuals in the community setting remains inconclusive. This study aimed to evaluate the effect of a 6-month weight loss lifestyle intervention on cardiometabolic risk factors among overweight and obese women and the sustainability of the changes in those markers at 12-month follow-up, comparing an intervention group with a control group. Methods: A total of 243 participants from MyBFF@home were included in this study. Fasting blood samples at baseline, 6- and 12-month were assessed for fasting plasma glucose (FPG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides. The effect of the intervention on cardiometabolic risk markers were investigated within and between study groups using t-test and general linear model (GLM) repeated measure ANOVA. Results: Results from repeated measures ANOVA showed intervention effect only in TC where significant reduction was found in the intervention group (− 0.26 mmol/L [95% CI: – 0.47 to − 0.06], p < 0.01) compared to the control group (− 0.06 mmol/L [95% CI: – 0.28 to 0.17]) at 12 months. At 6 months, TC was reduced significantly in both groups but only intervention group retained the reduction in maintenance phase while, the level increased significantly in the control group (0.22 mmol/L [95% CI: 0.06 to 0.38]). This attributed to significant increase in TC/HDL-C ratio in the control group during maintenance phase (0.32 [95% CI: 0.15 to 0.50], p < 0.001). The intervention group also showed trend of reduction in FPG at 6 months and further decreased during maintenance phase (− 0.19 mmol/L [95% CI: – 0. 32 to − 0.06], p < 0.01). At 6 months HDL-C was maintained in the intervention group but reduced significantly in the control group (− 0.05 mmol/L [95% CI: – 0.10 to − 0.01], p < 0.05). No significant difference was detected in both markers when compared between groups. Conclusions: In the context of low socio-economic communities, this study supports that weight loss related lifestyle modifications over a 6-month period could improve selected cardiometabolic risk factors, particularly fasting glucose, TC and HDL-C in overweight and obese women with favourable sustainability over a 12-month period.
- PublicationUnplanned Pregnancy and Its Associated Factors(2018)INTRODUCTION: Unplanned pregnancy is a major public health concern globally. Numerous studies found various factors that can predict or determine unplanned pregnancy. However, there were no studies that reported this problem in Malaysia. The objective of this study is to determine the prevalence of unplanned pregnancy in Malaysia and the associated factors. METHODS: This nationwide cross-sectional study targeted to women at postpartum period at government primary health care clinics throughout Malaysia. Structured questionnaire with face-to-face interview was used for data collection. The factors studied included mothers’ age, husband’s age, ethnicity, religion, marital status, education, occupation, household income, polygamous marriage, family support, contraception used, and disagreement of husband on contraception, smoking and alcohol consumption. History of emotional, physical and sexual intimate partner violence (IPV) were also studied. RESULTS: A total of 5727 Malaysian postpartum mothers were involved in this survey. The prevalence of unplanned pregnancy was 42.9% (95% CI: 38.6, 47.4). The multivariate logistic regression revealed that older mothers aged 45-49 years old (aOR: 8.010; 95%CI: 1.909, 33.013) and Muslim mothers (aOR: 2.465; 95%CI: 1.432-4.241) were significantly associated with unplanned pregnancy. In terms of household income, mothers with less than RM1000 per month were 1.712 (95% CI: 1.080, 2.713) times more likely to have unplanned pregnancy. The other significant associated factor was history of emotional intimate partner violence; aOR [1.720 (95% CI: 1.011, 2.925)]. CONCLUSIONS: Unplanned pregnancies were observed to be higher among older Muslim women from low income family. A possibility of unmet need for family planning should be considered and appropriate intervention strategies planned for these at-risk population.
- PublicationPredictors of Recurrent Ischemic Stroke in Obese Patients With Type 2 Diabetes Mellitus: A Population-based Study(Elsevier, 2020)Background: Diabetes and obesity are established risk factors for stroke. The current study aimed to assess risk factors of ischemic stroke recurrence in diabetic patients based on their body mass index (BMI). Methods: A total of 4005 diabetic patients who had a history of ischemic stroke were identified in a retrospective cross-sectional dataset from the Malaysian National Neurology Registry. Patients were classified based on BMI, and multivariable regression analysis was used to evaluate the association between risk factors and recurrent ischemic stroke. Results: Among obese patients, those with ischemic heart disease (aOR, 1.873; 95% CI, 1.131–3.103), received formal education (aOR, 2.236; 95% CI, 1.306–3.830), and received anti-diabetic medication (aOR, 1.788; 95% CI, 1.180–2.708) had a higher stroke recurrence risk, while receiving angiotensin receptors blockers (aOR, 0.261; 95% CI, 0.126–0.543) lowered the odds of recurrence. Overweight patients with hypertension (aOR, 1.011; 95% CI, 1.002–1.019) for over 10 years (aOR, 3.385; 95% CI, 1.088–10.532) and diabetes prior to the first stroke (aOR, 1.823; 95% CI, 1.020–3.259) as well as those received formal education (aOR, 2.403; 95% CI, 1.126–5.129) had higher odds of stroke recurrence, while receiving angiotensin-converting enzyme inhibitors (aOR, 0.244; 95% CI, 0.111–0.538) lowered the recurrence risk. Normal weight East Malaysians (aOR, 0.351; 95% CI, 0.164–0.750) receiving beta-blockers (aOR, 0.410; 95% CI, 0.174–0.966) had lower odds of stroke recurrence. Conclusions: Ischemic heart disease, hypertension, receiving anti-hypertensive agents, and educational level were independent predictors of recurrent stroke in obese patients. Managing the modifiable risk factors can decrease the odds of stroke recurrence.
- PublicationSpecial pathology and therapeutics of the diseases of domestic animals: Volume III - diseases of the urinary organs, blood and blood producing organs, spleen, metabolism, nervous system, organ of locomotion, and skin(1938)Ruminants continue to be important in their traditional role in agricultural research and teaching. They are now also extensively used for studies in molecular biology; genetic engineering; and biotechnology for basic science, agricultural and clinical applications. Concern and interest for the welfare for these species and improved understanding of their biology and behavior have continued and are reflected in changing husbandry and management systems. This chapter addresses at high levels basic biology, husbandry, and the more common or important diseases of the three ruminant species used most commonly in the laboratory, namely sheep, goats and cattle.
- PublicationHLA in the Immune Response(Kuala Lumpur: Institute for Medical Research, 2012)When foreign antigen gains entry into the bod several important changes may by initiated , collectively known as the immune response , which result in the elimination of the alien antigen A remarkable feature of this phenomenon is the ability of the adult mammal to distinguish between its own antigens ( known as self antigen) and those external or foreign origin ( known as non self antigens) This means that as a general rule, antibody is selectively produced in response to foreign substances yet it is not produced to antigens that are recognized as "self