Selected Article of Journal (IMR)

The mosquito Aedes aegypti is an epidemic vector of several diseases such as dengue fever and yellow fever. Several pesticides are used to control the mosquito population. Because of their frequent use, some mosquitoes have developed resistance. In the present study, we evaluated the synergistic mosquito-repellent activity of essential oils from Pelargonium radula, Syzgium aromaticum and Citrus aurantifolia against Aedes aegypti by using Y-tube olfactometer. The oils was subsequently analyzed by GC–MS. These results clearly reveal that the essential oil of C. aurantifolia served as the most potent repellent agent against Aedes aegypti . The results indicate that three constituents; limonene (19.58%) followed by β–pinene (17.12%), geraniol (13.23%) which comprise a large proportion of the C. aurantifolia are likely responsible for the observed repellent activity.

Violence among adolescents is a significant public health issue. The focus was on school-going adolescents because of the life-long negative impact at an individual level both for the perpetrator and victim. Besides, it increases the costs to provide health, welfare, and criminal justice as well as decreases general productivity at the community level. The study aims to determine the prevalence of violence-related behavior, characteristics of both victims and perpetrators, in addition to inter and intrapersonal factors associated with violence-related behaviors. A study was carried out in 2013, which involved all upper secondary school students (aged 16 to 17 years). It was a part of the Malaysian Adolescent Health Risk Behavior (MyAHRB) study, which was conducted in 11 states in Peninsular Malaysia. Standardized, validated questionnaires were used for data collection. The prevalence of violence-related behaviors was 22.4%, and this was higher among male students as compared to females (29.1% vs. 16.3%). Multivariable analysis revealed that the odds of violence-related behaviour increased among males, Malay race, drug use, smoking, had exposure to sex, which sometimes and always felt lonely and had attempted suicide. Agreeable to ensure that their lifestyles do not transgress religious limit and belief was significantly protective. This study provides evidence for a targeted approach to combat violence-related behaviors among adolescents.

Epidemiological studies have found that particulate matter less than 10 microns in diameter (PM10) is hazardous to climate and human health. Population-weighted exposure level (PWEL) estimation is fundamental in providing quantitative assessments of areas where the population is vulnerable to the harmful pollutant. This study assesses PWEL of PM10 concentrations in all 16 states of Malaysia for years 2000, 2008 and 2013 using remote sensing and geographic information system (GIS). PM10 concentration estimation method from a local study was applied to validate the estimated PM10 annual mean concentrations with a spatial resolution of 5 kilometers retrieved from satellite data. Population count was obtained from the Gridded Population of the World version 4 (GPWv4) from the Center for International Earth Science Information Network (CIESIN). Estimated PM10 concentrations and gridded population count were then overlaid to generate PWEL of PM10. PWEL of PM10 for each state in Malaysia for the three years were then calculated to study the PWEL of PM10 trend. The concentrations of the pollutant were then classified based on the World Health Organization interim target (WHO IT) guideline. Increasing PWEL of PM10 were seen in 9 states over the 13-year period. Over those years, Putrajaya and Penang had the most increasing trend of PWEL of PM10 with an increment of 119% and 95% respectively. Putrajaya also had the highest recorded PWEL of PM10 (72 µg/m3) in 2013, exceeding the WHO IT class 1 guideline (70 µg/m3). Results based on human exposure analysis show the vulnerability was more towards urban and industrialized states. These results can be used as a decision-making tool and reference for health risk assessment on the population, areas, and sources that need more attention to curb air pollution.

Leptospirosis causes a wide range of clinical outcomes, including organ failure and death. Earlytreatment significantly increases the chances of cure. Interleukin-8 (IL-8) is a chemoattractant cytokine for neutrophil and is associated with multiple organ failure. Research has indicated IL 8 to be raised in severe and fatal cases of leptospirosis, but its suitability as a prognostic biomarker has yet to be confirmed. This study aimed to evaluate the significance of IL-8 with the clinical outcomes of leptospirosis patients. Plasma IL-8 was measured in fifty-two samples from hospitalized patients and nineteen healthy controls. The comparisons were made between mild, severe-survived and fatal groups identified by clinical or laboratory findings. IL-8 was significantly higher in fatal (p = 0.01) compared to mild cases. IL-8 was also significantly higher in fatal (p = 0.02) when compared to survived cases of leptospirosis. IL-8 levels in the plasma of fatal leptospirosis cases were significantly elevated compared to survived cases and may serve as a potential prognostic biomarker in determining the possible outcome of leptospirosis patients.

Autoinflammatory disorders are characterized by dysregulated innate immune response, resulting in recurrent uncontrolled systemic inflammation and fever. Gain-of-function mutations in NLRC4 have been described to cause a range of autoinflammatory disorders. We report a twelve-year-old Malay girl with recurrent fever, skin erythema, and inflammatory arthritis. Whole exome sequencing and subsequent bidirectional Sanger sequencing identified a heterozygous missense mutation in NLRC4 (NM_001199138: c.1970A > T). This variant was predicted to be damaging in silico, was absent in public and local databases and occurred in a highly conserved residue in the leucine-rich repeat (LRR) domain. Cytokine analysis showed extremely high serum IL-18 and IL 18/CXCL9 ratio, consistent with other NLRC4-MAS patients. In summary, we identified the first patient with a novel de novo heterozygous NLRC4 gene mutation contributing to autoinflammatory disease in Malaysia. Our findings reinforce the likely pathogenicity of specific LRR domain mutations in NLRC4 and expand the clinical spectrum of NLRC4 mutations.