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A Rare Case of a Distal Humerus Pathological Fracture from Klebsiella Pneumoniae Osteomyelitis: A Case Report

Chan MF, Kwek E

Malays Orthop J, 2020 Mar;14(1):81-83.
PMID: 32296487 DOI: 10.5704/MOJ.2003.013

Klebsiella pneumoniae is one of the leading causative organisms in pyogenic liver disease. It can cause disseminated infections, but rarely to bone, and rarely in healthy hosts. We report an unusual case of a distal humerus fracture from osteomyelitis secondary to dissemination in a non-immuno-compromised patient. The patient was surgically managed with external fixation and insertion of anti-biotic beads, in conjunction with medical therapy via culture direct antibiotics. This report highlights the diagnostic approach and treatment options for these atypical cases.
Factors affecting life expectancy: evidence from 1980-2009 data in Singapore, Malaysia, and Thailand

Chan MF, Devi MK

Asia Pac J Public Health, 2015 Mar;27(2):136-46.
PMID: 22865722 DOI: 10.1177/1010539512454163

The authors aim to examine the impact of demographic changes, socioeconomic inequality, and the availability of health care resources on life expectancy in Singapore, Malaysia, and Thailand. This is a cross-country study collecting annual data from 3 Southeast Asian countries from 1980 to 2008. Life expectancy is the dependent variable with demographics, socioeconomic status, and health care resources as the 3 main determinants. A structural equation model is used, and results show that the availability of more health care resources and higher levels of socioeconomic advantages are more likely to increase life expectancy. In contrast, demographic changes are more likely to increase life expectancy by way of health care resources. The authors suggest that more effort should be taken to expand and improve the coverage of health care programs to alleviate regional differences in health care use and improve the overall health status of people in these 3 Southeast Asian countries.
Fulltext Use of new radiochromic devices for peripheral dose measurement: potential in-vivo dosimetry application

Chiu-Tsao ST, Chan M

Biomed Imaging Interv J, 2009 Oct;5(4):e16.
PMID: 21610987 DOI: 10.2349/biij.5.4.e16

The authors have studied the feasibility of using three new high-sensitivity radiochromic devices in measuring the doses to peripheral points outside the primary megavoltage photon beams. The three devices were GAFCHROMIC® EBT film, prototype Low Dose (LD) Film, and prototype LD Card. The authors performed point dosimetry using these three devices in water-equivalent solid phantoms at x = 3,5,8,10, and 15 cm from the edge of 6 MV and 15 MV photon beams of 10x10 cm(2), and at depths of 0, 0.5 cm, and depth of maximum dose. A full sheet of EBT film was exposed with 5000 MU. The prototype LD film pieces were 1.5x2 cm(2) in size. Some LD films were provided in the form of a card in 1.8x5 cm(2) holding an active film in 1.8x2 cm(2). These are referred to as "LD dosimeter cards". The small LD films and cards were exposed with 500 MU. For each scanned film, a 6 mm circular area centered at the measurement point was sampled and the mean pixel value was obtained. The calibration curves were established from the calibration data for each combination of film/cards and densitometer/scanner. The doses at the peripheral points determined from the films were compared with those obtained using ion chamber at respective locations in a water phantom and general agreements were found. It is feasible to accurately measure peripheral doses of megavoltage photon beams using the new high-sensitivity radiochromic devices. This near real-time and inexpensive method can be applied in a clinical setting for dose measurements to critical organs and sensitive patient implant devices.
Fulltext Evaluation of imaging performance of major image guidance systems

Chan M, Yang J, Song Y, Burman C, Chan P, Li S

Biomed Imaging Interv J, 2011 Apr;7(2):e11.
PMID: 22287985 DOI: 10.2349/biij.7.2.e11

PURPOSE: The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in image-guided radiation therapy (IGRT) were evaluated.
MATERIALS AND METHODS: The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image quality including image noise, uniformity, density accuracy, spatial resolution, contrast linearity, and contrast resolution. The measurement results were analysed using in-house image analysis software. Reproducibility, position correction, and geometric accuracy were also evaluated with markers in a smaller alignment phantom. The performance evaluation compared volumetric image properties from these four systems with those from a conventional diagnostic CT (CCT).
RESULTS: It was shown that the linearity of the two kV CBCT was fairly consistent with CCT. The Elekta CBCT with half-circle 27-cm FOV had higher CT numbers than the other three systems. The image noises of the Elekta kV CBCT, Siemens MV CBCT, and Tomotherapy fan-beam CT (FBCT) are about 2-4 times higher than that of the Varian CBCT. The spatial resolutions of two kV CBCTs and two MV CBCTs were 8-11 lp/cm and 3-5 lp/cm, respectively.
CONCLUSION: Elekta CBCT provided a faster image reconstruction and low dose per scan for half-circle scanning. Varian CBCT had relatively lower image noise. Tomotherapy FBCT had the best uniformity.
The prevalence of internet gaming disorders and the associated psychosocial risk factors among adolescents in Malaysian secondary schools

Mohamed NF, Ab Manan N, Muhammad Firdaus Chan MF, Rahmatullah B, Abd Wahab R, Baharudin SNA, et al.

Clin Child Psychol Psychiatry, 2023 Oct;28(4):1420-1434.
PMID: 36927134 DOI: 10.1177/13591045231164870

Internet Gaming Disorder (IGD) has been placed under the conditions for further study segment in DSM-5. The purpose of the current study was to develop a preliminary psychosocial model as a reference for providing appropriate intervention, particularly for adolescents with IGD. A total of 5290 adolescents from secondary schools in seven states in Malaysia were recruited by using proportionate random sampling. A standardized set of validated questionnaires such as DASS-21, BIS-11, and IGDS9-SF were distributed to participants that fulfilled the inclusion criteria. The prevalence of IGD among Malaysian adolescents was 3.5%. The bivariate analysis summarized that factors such as stress, impulsivity, gender, time spent using the internet, and relationship with parents and friends; have statistically significant associations with IGD. The logistic regression model revealed that adolescents with IGD were 9 times more likely to experience extremely severe stress (p < 0.001). Several psychosocial factors were associated strongly with IGD in the current study, however, mental health shows the most significant issues among adolescents with IGD. Immediate intervention through a psychological approach to internet gaming is needed from parents, schools, and also respective stakeholders. IGD may become one of the addictions diseases that cause deterioration in many aspects of an adolescent's future life without serious intervention.
Prevalence and predictors of social anxiety disorders among Malaysian secondary school students during the COVID-19 pandemic: Exploring the influence of internet gaming disorder and impulsivity

Mohamed NF, Jiun Ting T, Ab Manan N, Mohd Senari IF, Muhammad Firdaus Chan MF, Rahmatullah B, et al.

Clin Child Psychol Psychiatry, 2024 Jan 01.
PMID: 38163335 DOI: 10.1177/13591045231206967

This study aimed to investigate the prevalence of social anxiety disorder (SAD) among Malaysian secondary school students during the COVID-19 pandemic and to explore its correlations with demographic variables, impulsivity behavior, and internet gaming disorder (IGD). A total of 1574 participants from 12 government secondary schools across five Malaysian states, comprising 569 males and 1005 females, completed an online questionnaire containing validated Malay versions of the Social Interaction Anxiety Scale, Barratt Impulsiveness Scale, and Internet Gaming Disorder Scale - Short Form. The findings revealed a notable SAD prevalence rate of 40.53% among Malaysian adolescents. Logistic regression analysis unveiled significant associations between SAD and factors such as attention impulsiveness (OR = 2.58, p < .001), motor impulsiveness (OR = 1.47, p = .03), female gender (OR = 2, p < .001), Malay ethnicity, and IGD (OR = 1.08, p < .001). In conclusion, this study provides valuable insights into the extent of social anxiety experienced by Malaysian secondary school students during the pandemic, shedding light on the demographic and psychosocial factors linked to its emergence. Furthermore, the research underscores a robust link between IGD and SAD, emphasizing the need for comprehensive interventions addressing both issues concurrently. By recognizing the multifaceted nature of these associations, future interventions can be tailored to provide holistic support for adolescents' mental well-being.