Displaying publications 121 - 140 of 146 in total

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  1. Yaiw KC, Crameri G, Wang L, Chong HT, Chua KB, Tan CT, et al.
    J Infect Dis, 2007 Sep 15;196(6):884-6.
    PMID: 17703419
    Tioman virus, a relatively new paramyxovirus, was isolated from fruit bats (Pteropus species) on Tioman Island, Malaysia, in 2001. The objective of this study was to determine the prevalence of antibodies to T. virus in island inhabitants, by use of comparative ELISA and serum neutralization assays. Of the 169 human sera analyzed, 5 (approximately 3.0%) were positive for T. virus, by comparative ELISA. Of these 5 sera, 3 (1.8% of the total) had neutralizing antibodies against T. virus, suggesting previous infection of this study population by this virus or a similar virus.
  2. Sunasee S, Leong KH, Wong KT, Lee G, Pichiah S, Nah I, et al.
    Environ Sci Pollut Res Int, 2019 Jan;26(2):1082-1093.
    PMID: 28290089 DOI: 10.1007/s11356-017-8729-7
    Since bisphenol A (BPA) exhibits endocrine disrupting action and high toxicity in aqueous system, there are high demands to remove it completely. In this study, the BPA removal by sonophotocatalysis coupled with nano-structured graphitic carbon nitride (g-C3N4, GCN) was conducted with various batch tests using energy-based advanced oxidation process (AOP) based on ultrasound (US) and visible light (Vis-L). Results of batch tests indicated that GCN-based sonophotocatalysis (Vis-L/US) had higher rate constants than other AOPs and especially two times higher degradation rate than TiO2-based Vis-L/US. This result infers that GCN is effective in the catalytic activity in Vis-L/US since its surface can be activated by Vis-L to transport electrons from valence band (VB) for utilizing holes (h+VB) in the removal of BPA. In addition, US irradiation exfoliated the GCN effectively. The formation of BPA intermediates was investigated in detail by using high-performance liquid chromatography-mass spectrometry (HPLC/MS). The possible degradation pathway of BPA was proposed.
  3. Sunasee S, Wong KT, Lee G, Pichiah S, Ibrahim S, Park C, et al.
    Environ Sci Pollut Res Int, 2017 Jun;24(18):15488-15499.
    PMID: 28512708 DOI: 10.1007/s11356-017-9124-0
    In this study, bisphenol A (BPA) removal by sonophotocatalysis coupled with commercially available titanium dioxide (TiO2, P25) was assessed in batch tests using energy-based advanced oxidation combining ultrasound (US) and ultraviolet (UV). The kinetics of BPA removal were systematically evaluated by changing operational parameters, such as US frequency and power, mechanical stirring speed, and temperature, but also comparison of single and coupled systems under the optimum US conditions (35 kHz, 50 W, 300 rpm stirring speed, and 20 °C). The combination of US/UV/P25 exhibited the highest BPA removal rate (28.0 × 10-3 min-1). In terms of the synergy index, the synergistic effect of sonophotocatalysis was found to be 2.2. This indicated that sonophotocatalysis has a considerably higher removal efficiency than sonocatalysis or photocatalysis. The removal of BPA was further investigated to identify BPA byproducts and intermediates using high-performance liquid chromatography-mass spectrometry. Five main intermediates were formed during sonophotocatalytic degradation, and complete removal of BPA and its intermediates was obtained after 3 h of operation. The degradation pathway of BPA by sonophotocatalysis was also elucidated.
  4. Tan KY, Deng S, Tan TK, Hari R, Sitam FT, Othman RY, et al.
    PeerJ, 2023;11:e16002.
    PMID: 37810781 DOI: 10.7717/peerj.16002
    BACKGROUND: The Malayan pangolin (Manis javanica) is a placental mammal and is listed as Critically Endangered on the IUCN Red List of Threatened Species. Most previous attempts to breed pangolins in captivity have met with little success because of dietary issues, infections, and other complications, although a previous study reported breeding pangolins in captivity to the third generation. In our previous pangolin genome sequencing data analysis, we obtained a considerable amount of bacterial DNA from a pregnant female Malayan pangolin (named "UM3"), which was likely infected by Paraburkholderia fungorum-an agent of biodegradation and bioremediation in agriculture.

    METHODOLOGY: Here, we further confirmed and characterized this bacterial species using PCR, histological staining, whole-genome sequencing, and bioinformatics approaches. PCR assays with in-house designed primer sets and 16S universal primers showed clear positive bands in the cerebrum, cerebellum, lung, and blood of UM3 suggesting that UM3 might have developed septicaemia. Histological staining showed the presence of Gram-negative rod-shaped bacteria in the pangolin brain and lungs, indicating the colonization of the bacteria in these two organs. In addition, PCR screening of UM3's fetal tissues revealed the presence of P. fungorum in the gastrocnemius muscle, but not in other tissues that we examined. We also sequenced and reconstructed the genome of pangolin P. fungorum, which has a genome size of 7.7 Mbps.

    CONCLUSION: Our study is the first to present detailed evidence of the presence of P. fungorum in a pangolin and her fetus (although preliminary results were presented in our previous article). Here, we raise the concern that P. fungorum may potentially infect humans, especially YOPI (young, old, pregnant, and immunocompromised) people. Therefore, caution should be exercised when using this bacterial species as biodegradation or bioremediation agents in agriculture.

  5. Zhang J, Mohamad FH, Wong JH, Mohamad H, Ismail AH, Mohamed Yusoff AA, et al.
    Malays J Med Sci, 2018 Feb;25(1):101-113.
    PMID: 29599640 DOI: 10.21315/mjms2018.25.1.12
    Background: Bamboo shoot has been used as a treatment for epilepsy in traditional Chinese medicine for generations to treat neuronal disorders such as convulsive, dizziness and headaches. 4-hydroxybenzoic acid (4-hba) is a non-flavonoid phenol found abundantly inDendrocalamus aspershoots (bamboo), fruits (strawberries and apples) and flowers. Kv1.4 is a rapidly inactivatingShaker-related member of the voltage-gated potassium channels with two inactivation mechanisms; the fast N-type and slow C-type. It plays vital roles in repolarisation, hyperpolarisation and signaling the restoration of resting membrane potential through the regulation of the movement of K+across the cellular membrane.

    Methods: Chemical compounds fromDendrocalamus asperbamboo shoots were purified and identified as major palmitic acids mixed with other minor fatty acids, palmitic acid, 4-hydroxybenzaldehyde, lauric acid, 4-hydroxybenzoic acid and cholest-4-ene-3-one. The response of synthetic 4-hydroxybenzoic acid was tested on Kv1.4 potassium channel which was injected into viable oocytes that was extracted fromXenopus laevis. The current were detected by the two-microelectrode voltage clamp, holding potential starting from -80 mV with 20 mV step-up until +80 mV. Readings of treatments with 0.1% DMSO, 4-hba concentrations and K channel blockers were taken at +60 mV. The ratio of tail/peak amplitude is the index of the activity of the Kv1.4 channels withn≥ 6 (number of oocytes tested). The decreases of the ratios of five different concentrations (1 μM, 10 μM, 100 μM, 1 mM and 2.5 mM) were compared with 0.1% DMSO as the control.

    Results: All concentration showed statistically significant results withP< 0.05 except for 100 μM. The normalised current of the 4-hba concentrations were compared with potassium channel blockers (TEA and 4-AP) and all groups showed statistically significant results. This study also showed that time taken for each concentration to affect Kv1.4 does not play any significant roles.

    Conclusion: 4-hydroxybenzoic acid was found to be able to enhance the inactivation of Kv1.4 by lowering the membrane potential so that the abnormal neuronal firing can be inhibited. With IC50 slightly higher than 10 μM, increasing concentrations (100 μM, 1 mM and 2.5 mM) had shown to exhibit toxicity effects. The best concentration from this study is 10 μM with Hill slope of 0.1799.

  6. Tan CT, Goh KJ, Wong KT, Sarji SA, Chua KB, Chew NK, et al.
    Ann Neurol, 2002 Jun;51(6):703-8.
    PMID: 12112075
    An outbreak of infection with the Nipah virus, a novel paramyxovirus, occurred among pig farmers between September 1998 and June 1999 in Malaysia, involving 265 patients with 105 fatalities. This is a follow-up study 24 months after the outbreak. Twelve survivors (7.5%) of acute encephalitis had recurrent neurological disease (relapsed encephalitis). Of those who initially had acute nonencephalitic or asymptomatic infection, 10 patients (3.4%) had late-onset encephalitis. The mean interval between the first neurological episode and the time of initial infection was 8.4 months. Three patients had a second neurological episode. The onset of the relapsed or late-onset encephalitis was usually acute. Common clinical features were fever, headache, seizures, and focal neurological signs. Four of the 22 relapsed and late-onset encephalitis patients (18%) died. Magnetic resonance imaging typically showed patchy areas of confluent cortical lesions. Serial single-photon emission computed tomography showed the evolution of focal hyperperfusion to hypoperfusion in the corresponding areas. Necropsy of 2 patients showed changes of focal encephalitis with positive immunolocalization for Nipah virus antigens but no evidence of perivenous demyelination. We concluded that a unique relapsing and remitting encephalitis or late-onset encephalitis may result as a complication of persistent Nipah virus infection in the central nervous system.
  7. Goh KJ, Tan CT, Chew NK, Tan PS, Kamarulzaman A, Sarji SA, et al.
    N Engl J Med, 2000 Apr 27;342(17):1229-35.
    PMID: 10781618 DOI: 10.1056/NEJM200004273421701
    BACKGROUND: Between September 1998 and June 1999, there was an outbreak of severe viral encephalitis due to Nipah virus, a newly discovered paramyxovirus, in Malaysia.
    METHODS: We studied the clinical features of the patients with Nipah virus encephalitis who were admitted to a medical center in Kuala Lumpur. The case definition was based on epidemiologic, clinical, cerebrospinal fluid, and neuroimaging findings.
    RESULTS: Ninety-four patients with Nipah virus infection were seen from February to June 1999 (mean age, 37 years; ratio of male patients to female patients, 4.5 to 1). Ninety-three percent had had direct contact with pigs, usually in the two weeks before the onset of illness, suggesting that there was direct viral transmission from pigs to humans and a short incubation period. The main presenting features were fever, headache, dizziness, and vomiting. Fifty-two patients (55 percent) had a reduced level of consciousness and prominent brain-stem dysfunction. Distinctive clinical signs included segmental myoclonus, areflexia and hypotonia, hypertension, and tachycardia and thus suggest the involvement of the brain stem and the upper cervical spinal cord. The initial cerebrospinal fluid findings were abnormal in 75 percent of patients. Antibodies against Hendra virus were detected in serum or cerebrospinal fluid in 76 percent of 83 patients tested. Thirty patients (32 percent) died after rapid deterioration in their condition. An abnormal doll's-eye reflex and tachycardia were factors associated with a poor prognosis. Death was probably due to severe brain-stem involvement. Neurologic relapse occurred after initially mild disease in three patients. Fifty patients (53 percent) recovered fully, and 14 (15 percent) had persistent neurologic deficits.
    CONCLUSIONS: Nipah virus causes a severe, rapidly progressive encephalitis with a high mortality rate and features that suggest involvement of the brain stem. The infection is associated with recent contact with pigs.
  8. Goldsmith CS, Whistler T, Rollin PE, Ksiazek TG, Rota PA, Bellini WJ, et al.
    Virus Res, 2003 Mar;92(1):89-98.
    PMID: 12606080
    Nipah virus, which was first recognized during an outbreak of encephalitis with high mortality in Peninsular Malaysia during 1998-1999, is most closely related to Hendra virus, another emergent paramyxovirus first recognized in Australia in 1994. We have studied the morphologic features of Nipah virus in infected Vero E6 cells and human brain by using standard and immunogold electron microscopy and ultrastructural in situ hybridization. Nipah virions are enveloped particles composed of a tangle of filamentous nucleocapsids and measured as large as 1900 nm in diameter. The nucleocapsids measured up to 1.67 microm in length and had the herringbone structure characteristic for paramyxoviruses. Cellular infection was associated with multinucleation, intracytoplasmic nucleocapsid inclusions (NCIs), and long cytoplasmic tubules. Previously undescribed for other members of the family Paramyxoviridae, infected cells also contained an inclusion formed of reticular structures. Ultrastructural ISH studies suggest these inclusions play an important role in the transcription process.
  9. Low SC, Md Sari NA, Tan CY, Ahmad-Annuar A, Wong KT, Law WC, et al.
    Neuromuscul Disord, 2021 07;31(7):642-650.
    PMID: 34059423 DOI: 10.1016/j.nmd.2021.03.008
    We report the clinical and genetic characteristics of hereditary transthyretin amyloidosis in the multi-ethnic Malaysian population. Subjects with genetically confirmed transthyretin amyloidosis seen between 2001 till August 2020 were included. There were 30 patients and 14 asymptomatic carriers, of which 26 (59.1%) were men. The majority (86.7%) were ethnic Chinese while two (6.7%) each were Malay and Sri Lankan Tamil ethnicity respectively. Among patients, mean age of symptom-onset was 55.9 ± 9.8 years with mean duration from symptom-onset to diagnosis of 3.2 ± 2.5 years. Common presenting symptoms were sensory symptoms of upper limbs (43.3%), symmetric sensory symptoms of both lower limbs (16.7%) and autonomic symptoms (16.7%). Nerve conduction studies showed sensorimotor polyneuropathy in 25 (83.3%) patients (22, axonal). Abnormal echocardiograms were seen in 24 (80%) patients, although 15 were asymptomatic. Of six different TTR mutations found, Ala97Ser was the commonest, and found exclusively in 84.6% of Chinese patients. Other mutations among Chinese patients were Val30Met, Ala25Thr and Asp39Val. Our Malay and Tamil patients had Glu54Lys and Gly47Val mutations respectively. In conclusion, TTR Ala97Ser is the commonest mutation among ethnic Chinese Malaysians which presented with late-onset progressive sensorimotor polyneuropathy, autonomic dysfunction and subclinical cardiac involvement.
  10. Rajagopal R, Abd-Ghafar S, Ganesan D, Bustam Mainudin AZ, Wong KT, Ramli N, et al.
    J Glob Oncol, 2017 Apr;3(2):143-156.
    PMID: 28717752 DOI: 10.1200/JGO.2015.002659
    PURPOSE: Pediatric medulloblastoma (MB) treatment has evolved over the past few decades; however, treating children in countries with limited resources remains challenging. Until now, the literature regarding childhood MB in Malaysia has been nonexistent. Our objectives were to review the demographics and outcome of pediatric MB treated at the University Malaya Medical Center between January 1994 and December 2013 and describe the challenges encountered.

    METHODS: Fifty-one patients with childhood MB were seen at University Malaya Medical Center. Data from 43 patients were analyzed; eight patients were excluded because their families refused treatment after surgery.

    RESULTS: Headache and vomiting were the most common presenting symptoms, and the mean interval between symptom onset and diagnosis was 4 weeks. Fourteen patients presented with metastatic disease. Five-year progression-free survival (± SE) for patients ≥ 3 years old was 41.7% ± 14.2% (95% CI, 21.3% to 81.4%) in the high-risk group and 68.6% ± 18.6% (95% CI, 40.3% to 100%) in the average-risk group, and 5-year overall survival (± SE) in these two groups was 41.7% ± 14.2% (95% CI, 21.3% to 81.4%) and 58.3% ± 18.6% (95% CI, 31.3% to 100%), respectively. Children younger than 3 years old had 5-year progression-free and overall survival rates (± SE) of 47.6% ± 12.1% (95% CI, 28.9% to 78.4%) and 45.6% ± 11.7% (95% CI, 27.6% to 75.5%), respectively. Time to relapse ranged from 4 to 132 months. Most patients who experienced relapse died within 1 year. Febrile neutropenia, hearing loss, and endocrinopathy were the most common treatment-related complications.

    CONCLUSION: The survival rate of childhood MB in Malaysia is inferior to that usually reported in the literature. We postulate that the following factors contribute to this difference: lack of a multidisciplinary neuro-oncology team, limited health care facilities, inconsistent risk assessment, insufficient data in the National Cancer Registry and pathology reports, inadequate long-term follow-up, and cultural beliefs leading to treatment abandonment.

  11. Abubakar S, Teoh BT, Sam SS, Chang LY, Johari J, Hooi PS, et al.
    Emerg Infect Dis, 2013 Dec;19(12):1989-91.
    PMID: 24274071 DOI: 10.3201/eid1912.120530
    An outbreak of fever associated with myalgia and myositis occurred in 2012 among 89 of 92 college students and teachers who visited Pangkor Island, Malaysia. The Sarcocystis nesbitti 18S rRNA gene and sarcocysts were obtained from muscle tissues of 2 students. Our findings indicate emergence of S. nesbitti infections in humans in Malaysia.
  12. Junaid QO, Khaw LT, Mahmud R, Ong KC, Lau YL, Borade PU, et al.
    Parasite, 2017;24:38.
    PMID: 29034874 DOI: 10.1051/parasite/2017040
    BACKGROUND: As the quest to eradicate malaria continues, there remains a need to gain further understanding of the disease, particularly with regard to pathogenesis. This is facilitated, apart from in vitro and clinical studies, mainly via in vivo mouse model studies. However, there are few studies that have used gerbils (Meriones unguiculatus) as animal models. Thus, this study is aimed at characterizing the effects of Plasmodium berghei ANKA (PbA) infection in gerbils, as well as the underlying pathogenesis.

    METHODS: Gerbils, 5-7 weeks old were infected by PbA via intraperitoneal injection of 1 × 106 (0.2 mL) infected red blood cells. Parasitemia, weight gain/loss, hemoglobin concentration, red blood cell count and body temperature changes in both control and infected groups were monitored over a duration of 13 days. RNA was extracted from the brain, spleen and whole blood to assess the immune response to PbA infection. Organs including the brain, spleen, heart, liver, kidneys and lungs were removed aseptically for histopathology.

    RESULTS: Gerbils were susceptible to PbA infection, showing significant decreases in the hemoglobin concentration, RBC counts, body weights and body temperature, over the course of the infection. There were no neurological signs observed. Both pro-inflammatory (IFNγ and TNF) and anti-inflammatory (IL-10) cytokines were significantly elevated. Splenomegaly and hepatomegaly were also observed. PbA parasitized RBCs were observed in the organs, using routine light microscopy and in situ hybridization.

    CONCLUSION: Gerbils may serve as a good model for severe malaria to further understand its pathogenesis.

  13. Chen KS, Bridges CR, Lynton Z, Lim JWC, Stringer BW, Rajagopal R, et al.
    J Neurooncol, 2020 Jan;146(1):41-53.
    PMID: 31760595 DOI: 10.1007/s11060-019-03352-3
    INTRODUCTION: Malignant astrocytomas are composed of heterogeneous cell populations. Compared to grade IV glioblastoma, low-grade astrocytomas have more differentiated cells and are associated with a better prognosis. Therefore, inducing cellular differentiation to alter the behaviour of high-grade astrocytomas may serve as a therapeutic strategy. The nuclear factor one (NFI) transcription factors are essential for normal astrocytic differentiation. Here, we investigate whether family members NFIA and NFIB act as effectors of cellular differentiation in glioblastoma.

    METHODS: We analysed expression of NFIA and NFIB in mRNA expression data of high-grade astrocytoma and with immunofluorescence co-staining. Furthermore, we induced NFI expression in patient-derived subcutaneous glioblastoma xenografts via in vivo electroporation.

    RESULTS: The expression of NFIA and NFIB is reduced in glioblastoma as compared to lower grade astrocytomas. At a cellular level, their expression is associated with differentiated and mature astrocyte-like tumour cells. In vivo analyses consistently demonstrate that expression of either NFIA or NFIB is sufficient to promote tumour cell differentiation in glioblastoma xenografts.

    CONCLUSION: Our findings indicate that both NFIA and NFIB may have an endogenous pro-differentiative function in astrocytomas, similar to their role in normal astrocyte differentiation. Overall, our study establishes a basis for further investigation of targeting NFI-mediated differentiation as a potential differentiation therapy.

  14. Mohd Jaafar F, Attoui H, Gallian P, Isahak I, Wong KT, Cheong SK, et al.
    J Virol Methods, 2004 Mar 01;116(1):55-61.
    PMID: 14715307
    Banna virus (BAV, genus Seadornavirus, family Reoviridae) is an arbovirus suspected to be responsible for encephalitis in humans. Two genotypes of this virus are distinguishable: A (Chinese isolate, BAV-Ch) and B (Indonesian isolate, BAV-In6969) which exhibit only 41% amino-acid identity in the sequence of their VP9. The VP7 to VP12 of BAV-Ch and VP9 of BAV-In6969 were expressed in bacteria using pGEX-4T-2 vector. VP9 was chosen to establish an ELISA for BAV, based mainly on two observations: (i). VP9 is a major protein in virus-infected cells and is a capsid protein (ii). among all the proteins expressed, VP9 was obtained in high amount and showed the highest immuno-reactivity to anti-BAV ascitic fluid. The VP9s ELISA was evaluated in three populations: French blood donors and two populations (blood donors and patients with a neurological syndrome) from Malaysia, representing the region where the virus was isolated in the past. The specificity of this ELISA was >98%. In mice injected with live BAV, the assay detected IgG-antibody to BAV infection 21 days post-injection, which was confirmed by Western blot using BAV-infected cells. The VP9 ELISA permits to determine the sero-status of a population without special safety precautions and without any requirements to propagate the BAV. This test should be a useful tool for epidemiological survey of BAV.
  15. Wong KT, Grosjean I, Brisson C, Blanquier B, Fevre-Montange M, Bernard A, et al.
    Am J Pathol, 2003 Nov;163(5):2127-37.
    PMID: 14578210 DOI: 10.1016/S0002-9440(10)63569-9
    A predominantly pig-to-human zoonotic infection caused by the novel Nipah virus emerged recently to cause severe morbidity and mortality in both animals and man. Human autopsy studies showed the pathogenesis to be related to systemic vasculitis that led to widespread thrombotic occlusion and microinfarction in most major organs especially in the central nervous system. There was also evidence of extravascular parenchymal infection, particularly near damaged vessels (Wong KT, Shieh WJ, Kumar S, Norain K, Abdullah W, Guarner J, Goldsmith CS, Chua KB, Lam SK, Tan CT, Goh KJ, Chong HT, Jusoh R, Rollin PE, Ksiazek TG, Zaki SR, Nipah Virus Pathology Working Group: Nipah virus infection: Pathology and pathogenesis of an emerging paramyxoviral zoonosis. Am J Pathol 2002, 161:2153-2167). We describe here a golden hamster (Mesocricetus auratus) model that appears to reproduce the pathology and pathogenesis of acute human Nipah infection. Hamsters infected by intranasal or intraperitoneal routes died within 9 to 29 days or 5 to 9 days, respectively. Pathological lesions were most severe and extensive in the hamster brain. Vasculitis, thrombosis, and more rarely, multinucleated endothelial syncytia, were found in blood vessels of multiple organs. Viral antigen and RNA were localized in both vascular and extravascular tissues including neurons, lung, kidney, and spleen, as demonstrated by immunohistochemistry and in situ hybridization, respectively. Paramyxoviral-type nucleocapsids were identified in neurons and in vessel walls. At the terminal stage of infection, virus and/or viral RNA could be recovered from most solid organs and urine, but not from serum. The golden hamster is proposed as a suitable model for further studies including pathogenesis studies, anti-viral drug testing, and vaccine development against acute Nipah infection.
  16. Lim KS, Tan AH, Lim CS, Chua KH, Lee PC, Ramli N, et al.
    PLoS One, 2015;10(8):e0135470.
    PMID: 26270344 DOI: 10.1371/journal.pone.0135470
    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare hereditary stroke caused by mutations in NOTCH3 gene. We report the first case of CADASIL in an indigenous Rungus (Kadazan-Dusun) family in Kudat, Sabah, Malaysia confirmed by a R54C (c.160C>T, p.Arg54Cys) mutation in the NOTCH3. This mutation was previously reported in a Caucasian and two Korean cases of CADASIL. We recruited two generations of the affected Rungus family (n = 9) and found a missense mutation (c.160C>T) in exon 2 of NOTCH3 in three siblings. Two of the three siblings had severe white matter abnormalities in their brain MRI (Scheltens score 33 and 50 respectively), one of whom had a young stroke at the age of 38. The remaining sibling, however, did not show any clinical features of CADASIL and had only minimal changes in her brain MRI (Scheltens score 17). This further emphasized the phenotype variability among family members with the same mutation in CADASIL. This is the first reported family with CADASIL in Rungus subtribe of Kadazan-Dusun ethnicity with a known mutation at exon 2 of NOTCH3. The penetrance of this mutation was not complete during the course of this study.
  17. Zhang J, Mohamad H, Wong JH, Bilal M, Ismail AHB, Lloyd AJ, et al.
    Malays J Med Sci, 2017 Mar;24(2):94-99.
    PMID: 28894409 DOI: 10.21315/mjms2017.24.2.12
    The α1β2γ2 subtype of GABAA receptors is the most commonly found GABAA receptor subtype in the mammalian cortex and hippocampus. It is expressed heterologously in the Xenopus laevis oocyte as a α1β2γ2S/L subtype for application as an in vitro model for the screening of compounds that modulate receptor activities. In fact, 4-hydroxybenzaldehyde (4-HB) has been identified as one of the major components in Dendrocalamus asper bamboo shoots in our previous study, and the current study showed that at 101.7 μM, 4-HB significantly reduced the GABA-induced chloride current of GABAA receptors expressed on Xenopus oocytes, indicating a possible GABAergic antagonistic effect at high concentrations.
  18. Wong KT, Ng KY, Ong KC, Ng WF, Shankar SK, Mahadevan A, et al.
    Neuropathol. Appl. Neurobiol., 2012 Aug;38(5):443-53.
    PMID: 22236252 DOI: 10.1111/j.1365-2990.2011.01247.x
    To investigate if two important epidemic viral encephalitis in children, Enterovirus 71 (EV71) encephalomyelitis and Japanese encephalitis (JE) whose clinical and pathological features may be nonspecific and overlapping, could be distinguished.
  19. Costa H, Xu X, Overbeek G, Vasaikar S, Patro CP, Kostopoulou ON, et al.
    Oncotarget, 2016 Jul 26;7(30):47221-47231.
    PMID: 27363017 DOI: 10.18632/oncotarget.9722
    BACKGROUND: Both arginase (ARG2) and human cytomegalovirus (HCMV) have been implicated in tumorigenesis. However, the role of ARG2 in the pathogenesis of glioblastoma (GBM) and the HCMV effects on ARG2 are unknown. We hypothesize that HCMV may contribute to tumorigenesis by increasing ARG2 expression.

    RESULTS: ARG2 promotes tumorigenesis by increasing cellular proliferation, migration, invasion and vasculogenic mimicry in GBM cells, at least in part due to overexpression of MMP2/9. The nor-NOHA significantly reduced migration and tube formation of ARG2-overexpressing cells. HCMV immediate-early proteins (IE1/2) or its downstream pathways upregulated the expression of ARG2 in U-251 MG cells. Immunostaining of GBM tissue sections confirmed the overexpression of ARG2, consistent with data from subsets of Gene Expression Omnibus. Moreover, higher levels of ARG2 expression tended to be associated with poorer survival in GBM patient by analyzing data from TCGA.

    METHODS: The role of ARG2 in tumorigenesis was examined by proliferation-, migration-, invasion-, wound healing- and tube formation assays using an ARG2-overexpressing cell line and ARG inhibitor, N (omega)-hydroxy-nor-L-arginine (nor-NOHA) and siRNA against ARG2 coupled with functional assays measuring MMP2/9 activity, VEGF levels and nitric oxide synthase activity. Association between HCMV and ARG2 were examined in vitro with 3 different GBM cell lines, and ex vivo with immunostaining on GBM tissue sections. The viral mechanism mediating ARG2 induction was examined by siRNA approach. Correlation between ARG2 expression and patient survival was extrapolated from bioinformatics analysis on data from The Cancer Genome Atlas (TCGA).

    CONCLUSIONS: ARG2 promotes tumorigenesis, and HCMV may contribute to GBM pathogenesis by upregulating ARG2.

  20. Takeuchi F, Nakamura H, Yonemoto N, Komaki H, Rosales RL, Kornberg AJ, et al.
    Brain Dev, 2020 Mar;42(3):277-288.
    PMID: 31980267 DOI: 10.1016/j.braindev.2019.12.005
    BACKGROUND: Several studies on clinical practice for Duchenne muscular dystrophy (DMD) have been conducted in Western countries. However, there have been only a few similar studies in Asia and Oceania. Here, we investigate the steroid therapy-related clinical practice for DMD among the local experts. In 2015, we conducted a DMD expert survey in Asia and Oceania to acquire information regarding patients with DMD and to assess current clinical practice with the cooperation of Asian and Oceanian Myology Centre, a neuromuscular disease research network.

    RESULTS: We obtained survey responses from 87 out of 148 clinicians (62%) from 13 countries and regions. In China, 1385 DMD patients were followed-up by 5 respondent neurologists, and 84% were between 0 and 9 years of age (15% were 10-19 years, 1% > 19 years). While in Japan, 1032 patients were followed-up by 20 clinicians, and the age distribution was similar between the 3 groups (27% were 0-9 years, 35% were 10-19 years, 38% were >19 years). Most respondent clinicians (91%) were aware of DMD standard of care recommendations. Daily prednisolone/prednisone administration was used most frequently at initiation (N = 45, 64%). Inconsistent opinion on steroid therapy after loss of ambulation and medication for bone protection was observed.

    CONCLUSIONS: Rare disease research infrastructures have been underdeveloped in many of Asian and Oceanian countries. In this situation, our results show the snapshots of current medical situation and clinical practice in DMD. For further epidemiological studies, expansion of DMD registries is necessary.

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