We have developed and characterised a mouse model of Japanese encephalitis virus (JEV) infection via footpad inoculation in order to better mimic viral transmission by mosquito bites. Two-week-old and 5-week-old mice consistently developed signs of infection such as ruffled fur, weight loss, hunchback posture, tremors, mask-like facies and occasionally, hindlimb paralysis at 4 days post infection (dpi) and 11-13 dpi, respectively. Most of the animals died within 24 to 48 hours following the onset of signs of infection, with mortalities of 100% and 33.3% in 2-week-old and 5-week-old mice, respectively. Mild meningitis and variable parenchymal inflammation with formation of microglial nodules, focal necrosis and neuronophagia, and perivascular cuffing by inflammatory cells were observed in the caudate nucleus, putamen, thalamus, cerebral cortex, brainstem, and spinal cord. Viral antigens/RNA were demonstrated by immunohistochemisty and in situ hybridization, respectively, in most of these areas as well as in the hippocampus and cerebellum, albeit more focally. The pathological findings in this mouse model were generally similar to human Japanese encephalitis (JE) and other established JE models but perhaps, compared to other JEV mouse models, it demonstrates lethal encephalitic infection more consistently. We believe that our mouse model should be useful to study the pathogenesis of JE, and for testing anti-viral drugs and vaccines

We have developed and characterised a mouse model of Japanese encephalitis virus (JEV) infection via footpad inoculation in order to better mimic viral transmission by mosquito bites. Two-week-old and 5-week-old mice consistently developed signs of infection such as ruffled fur, weight loss, hunchback posture, tremors, mask-like facies and occasionally, hindlimb paralysis at 4 days post infection (dpi) and 11-13 dpi, respectively. Most of the animals died within 24 to 48 hours following the onset of signs of infection, with mortalities of 100% and 33.3% in 2-week-old and 5-week-old mice, respectively. Mild meningitis and variable parenchymal inflammation with formation of microglial nodules, focal necrosis and neuronophagia, and perivascular cuffing by inflammatory cells were observed in the caudate nucleus, putamen, thalamus, cerebral cortex, brainstem, and spinal cord. Viral antigens/RNA were demonstrated by immunohistochemisty and in situ hybridization, respectively, in most of these areas as well as in the hippocampus and cerebellum, albeit more focally. The pathological findings in this mouse model were generally similar to human Japanese encephalitis (JE) and other established JE models but perhaps, compared to other JEV mouse models, it demonstrates lethal encephalitic infection more consistently. We believe that our mouse model should be useful to study the pathogenesis of JE, and for testing anti-viral drugs and vaccines
Encephalitis, Japanese ; Virus Diseases

Myopathies, although presenting more commonly in the younger age group, can occur and contribute signifi cantly to disability in the elderly. To describe the spectrum of elderly myopathies, we reviewed 52 elderly patients (> 65 years) from the University of Malaya Medical Centre muscle biopsy databank, constituting 6.8% of 759 adult patients (> 18 years) who underwent muscle biopsy between 1992 and 2012. Commonest were the infl ammatory myopathies (41/52, 78.8%), of which 43.9% had dermatomyositis; 23.9% polymyositis; 14.6% sporadic inclusion body myositis; 9.8% undifferentiated myositis and 2.4% overlap myositis. Seven patients (13.4%) had genetic myopathy; 2 muscular dystrophy and 5 chronic progressive external ophthalmoplegia, while 4 patients (7.7%) had drug-associated myopathy, 3 with statins. Malignancies were seen in 9.8% of infl ammatory myopathies at diagnosis. Both acquired and genetic myopathies are seen in elderly Malaysians of all ethnicities and should not be misdiagnosed as some are potentially treatable and/or associated with malignancy.

Background and Objective: The promoter of the apolipoprotein E (APOE) gene is polymorphic at positions -491A/T, -427C/T and -219G/T. These single nucleotide polymorphisms may alter transcriptional activity and impact APOE expression due to differential binding of transcription factors. It has been suggested that the -491 A, -427 C and -219 T alleles are associated with a high risk of developing Alzheimer’s disease. This study aims to investigate the frequencies of APOE promoter polymorphisms in three major ethnic groups (Malay, Chinese and Indian) in Malaysia. Method: DNA was extracted from blood obtained from 290 healthy people (Malay: n= 92; Chinese: n= 105; and Indian: n= 93), and the promoter region was amplifi ed using PCR and genotyped by direct sequencing. Result: The Indian group has the lowest frequencies of - 491 A, - 427 C and - 219 T alleles (83.9%, 3.2% and 56.5%, respectively) compared to the Chinese group with the highest frequencies (97.1%, 11.9% and 67.1%, respectively). The frequencies in the Malay group were somewhere in between (94.6%, 8.2% and 61.4%, respectively). Moreover, for the - 491 and - 427 positions, the frequencies of possible genotypes viz., AA or AT or TT and CC or CT or TT, respectively, were statistically signifi cant (P < 0.05, Chi- Square Test) between the 3 ethnic groups. Conclusion: Based on the frequency of APOE promoter polymorphisms alone, the ethnic Indian may be predisposed to lower risks for AD than the Chinese or Malay.

Mitochondrial DNA (mtDNA) deletions are a major cause of chronic progressive external ophthalmoplegia (CPEO) and Kearns-Sayre syndrome (KSS). We analyzed single mtDNA deletions in 11 CPEO and one KSS patients by means of Southern blot and long polymerase chain reaction (PCR) assays. The deletion sizes ranged from 3.4 kb to 6.9 kb whereas the heteroplasmy level varied from 18.8% to 85.5%. Two unique deletions sized 4320 bp and 4717 bp were found. This study represents the first genetic screen of mtDNA disorders in Malaysia, and it follows the data seen in other published reports on CPEO and KSS genetic aetiology.

A cohort of Malaysian patients with clinico-pathological diagnosis of three specifi c mitochondrial encephalomyopathy syndromes comprising of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), myoclonus epilepsy with ragged-red fi bers (MERRF) and Leigh syndrome were studied to determine the frequency of their common mitochondrial DNA mutations. The ‘hot-spot’ point mutations for MELAS, MERRF and Leigh syndrome were screened. In the absence of common point mutations, screening of large-scale deletions as well as sequencing of tRNALeu and tRNALys genes were performed. Of 22 patients studied, nine m.3243A>G mutations, four m.8344A>G mutations, one m.8993T>G mutation and one deletion were identifi ed (65% detection rate). While the m.3243A>G mutation was closely associated with MELAS, the m.8344A>G was more heterogenous, being seen in one MERFF, two isolated mitochondrial myopathies and one Leigh syndrome patient. Screening for m.8993T>G in Leigh syndrome has a low yield as unsurprisingly Leigh syndrome has considerable genetic heterogeneity.

Aged, 80 and over ; Breast Neoplasms ; diagnosis ; Diffusion Magnetic Resonance Imaging ; Fatal Outcome ; Female ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Osteosarcoma ; diagnosis

Coxsackievirus A16 (CV-A16) is the leading cause of hand-foot-mouth disease (HFMD), which usually presents as mild and self-limiting symptoms in young children. Rarely, CV-A16 has been reported to cause severe and fatal neurological complications but little is known about these complications. In the present study, 1-day and 7-day old mouse models of CV-A16 were developed using a clinical strain via subcutaneous inoculation. All infected mice exhibited clinical signs of infection, including reduced mobility, limb weakness and paralysis between 3 to 6 days post-infection. Pathologically, the main organs involved were the central nervous system (CNS), skeletal muscles and brown fat. In the CNS, viral antigens as demonstrated by immunohistochemistry, were localized mainly to neurons in the brain stem and spinal cord, suggesting that CV-A16 is neurotropic although inflammation is very mild. The skeletal muscles showed necrosis and myositis due to viral infection as evidenced by the dense viral antigens. Focal viral antigens were also detected in the brown fat. These preliminary pathological findings indicate that our mouse models can be further developed to be useful models for pathogenesis studies, and vaccine and anti-viral drug evaluation.
Coxsackievirus Infections

Over 100 viruses are known to cause acute viral encephalitis in human. In order to diagnose a viral central nervous system infection, various laboratory diagnosis methods have been used. In this study, we examined 220 cerebrospinal fluid samples that were received at the Diagnostic Virology Laboratory of University Malaya Medical Centre between year 2004 to 2006, by viral isolation, pathogen specific antibody ELISA, polymerase chain reaction (PCR) and Real-Time PCR. Majority of the samples were from patients <10 years old. Out of 220 samples, 3 were positive for viral isolation, 27 for PCR (inclusive for the 3 positive for viral isolation) and 39 for pathogen specific ELISA. The total positive detection rate of this study was 30%. Herpes virus was the most important aetiologic agent, responsible for 58% of infection, followed by paramyxovirus (especially measles virus) in 26% of infection, and 14% by enterovirus. Parvovirus and flavivirus were the other common viruses. Among the herpes viruses, herpes simplex and cytomegalovirus were the most common.

Coxsackievirus A16 (CV-A16) is the leading cause of hand-foot-mouth disease (HFMD), which usually presents as mild and self-limiting symptoms in young children. Rarely, CV-A16 has been reported to cause severe and fatal neurological complications but little is known about these complications. In the present study, 1-day and 7-day old mouse models of CV-A16 were developed using a clinical strain via subcutaneous inoculation. All infected mice exhibited clinical signs of infection, including reduced mobility, limb weakness and paralysis between 3 to 6 days post-infection. Pathologically, the main organs involved were the central nervous system (CNS), skeletal muscles and brown fat. In the CNS, viral antigens as demonstrated by immunohistochemistry, were localized mainly to neurons in the brain stem and spinal cord, suggesting that CV-A16 is neurotropic although inflammation is very mild. The skeletal muscles showed necrosis and myositis due to viral infection as evidenced by the dense viral antigens. Focal viral antigens were also detected in the brown fat. These preliminary pathological findings indicate that our mouse models can be further developed to be useful models for pathogenesis studies, and vaccine and anti-viral drug evaluation.