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Ty AU, See SJ, Rao JP, Khoo JBK, Wong MC. Oligodendroglial tumor chemotherapy using "decreased-dose-intensity" PCV: A Singapore experience. Neurology 2006; 66:247-9. [PMID: 16434664 DOI: 10.1212/01.wnl.0000194211.68164.a0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors propose "decreased-dose-intensity" PCV (procarbazine, lomustine [CCNU], and vincristine) chemotherapy for Asian patients with oligodendroglial tumors. In this study, all seven patients with oligodendroglioma (OD) and eight with anaplastic oligodendroglioma (AO) had objective responses or stable disease. Median progression-free survival was greater than 29 months (OD) and 36.5 months or greater (AO); 86% of patients with OD and 63% with AO remain progression-free. Twenty-four Common Toxicity Criteria Grade 3/4 adverse events were noted.
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Tan EK, Yew K, Chua E, Shen H, Jamora RD, Lee E, Puong KY, Zhao Y, Pavanni R, Wong MC, Puvan K, Yih Y, Tan LCS. Analysis of PINK1 in Asian patients with familial parkinsonism. Clin Genet 2005; 68:468-70. [PMID: 16207217 DOI: 10.1111/j.1399-0004.2005.00500.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Skipper L, Shen H, Chua E, Bonnard C, Kolatkar P, Tan LCS, Jamora RD, Puvan K, Puong KY, Zhao Y, Pavanni R, Wong MC, Yuen Y, Farrer M, Liu JJ, Tan EK. Analysis of LRRK2 functional domains in nondominant Parkinson disease. Neurology 2005; 65:1319-21. [PMID: 16247070 DOI: 10.1212/01.wnl.0000180517.70572.37] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A comprehensive sequence analysis of 29 exons that code for the functional domains of LRRK2 in 160 nondominant Parkinson disease (PD) patients was performed. Novel variant screening in a further 470 sporadic PD patients and 630 controls revealed two novel variants (R1067Q and IVS33 + 6 T>A), which are likely to be pathogenic in five patients. One patient presented initially with a typical essential tremor phenotype, expanding the phenotypic spectrum of LRRK2 mutations.
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Tan EK, Puong KY, Chan DKY, Yew K, Fook-Chong S, Shen H, Ng PW, Woo J, Yuen Y, Pavanni R, Wong MC, Puvan K, Zhao Y. Impaired transcriptional upregulation of Parkin promoter variant under oxidative stress and proteasomal inhibition: clinical association. Hum Genet 2005; 118:484-8. [PMID: 16244875 DOI: 10.1007/s00439-005-0038-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 07/12/2005] [Indexed: 12/01/2022]
Abstract
We provided data to show that the transcriptional activity of wildtype -258T in the parkin promoter region was significantly higher than the -258G variant in human cell lines. The transcriptional activity of wildtype -258T was significantly increased under oxidative stress by hydrogen peroxide, but this was not observed for the -258G variant. The transcriptional upregulation was significantly higher for wildtype -258T compared to -258G variant at 0.1, 0.2 and 0.4 mM of hydrogen peroxide. Similar results were obtained when the cells were treated with a proteasome inhibitor, MG132.Furthermore, in a case control study involving 753 subjects, we demonstrated that the parkin promoter -258G variant was associated with an increased risk of sporadic Parkinson's disease (PD) in the elderly ethnic Chinese population. Our clinical and laboratory data provide corroborative evidence that some older individuals who have the -258G variant may have a higher risk of developing PD.
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Tan EK, Shen H, Tan LCS, Farrer M, Yew K, Chua E, Jamora RD, Puvan K, Puong KY, Zhao Y, Pavanni R, Wong MC, Yih Y, Skipper L, Liu JJ. The G2019S LRRK2 mutation is uncommon in an Asian cohort of Parkinson's disease patients. Neurosci Lett 2005; 384:327-9. [PMID: 15955629 DOI: 10.1016/j.neulet.2005.04.103] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2005] [Accepted: 04/30/2005] [Indexed: 11/18/2022]
Abstract
A common heterozygous leucine-rich repeat kinase 2 (LRRK2) mutation 6055G > A transition (G2019S) accounts for about 3-7% of familial Parkinson's disease (PD) and 1-1.6% sporadic PD in a number of European populations. To determine the prevalence of the G1019S mutation in our Asian population, we conducted genetic analysis of this mutation in 1000 PD and healthy controls. The G2019S mutation was not detected in any of our study subjects. The prevalence of G2019S mutation is rare (< 0.1%) in our population, suggesting that occurrence of this mutation may vary amongst different ethnic races. This has important clinical implication when implementing guidelines for genetic testing.
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Tan EK, Shen H, Tan JMM, Lim KL, Fook-Chong S, Hu WP, Paterson MC, Chandran VR, Yew K, Tan C, Yuen Y, Pavanni R, Wong MC, Puvan K, Zhao Y. Differential expression of splice variant and wild-type parkin in sporadic Parkinson's disease. Neurogenetics 2005; 6:179-84. [PMID: 16086186 DOI: 10.1007/s10048-005-0001-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Altered splicing of parkin under cellular stress could lead to changes in gene expression and altered protein activity. The causative role of parkin in sporadic Parkinson's disease (PD) is unknown. OBJECTIVES We described a parkin splice variant (SV) in the substantia nigra and leukocytes of sporadic PD patients. Using a case control methodology, we investigated the exon 4 SV (E4SV) and wild-type parkin expression in the leukocytes of sporadic PD patients and healthy individuals. METHODS/RESULTS We identified a parkin E4SV in the substantia nigra and leukocytes of sporadic PD patients and controls by reverse transcriptase-polymerase chain reaction (PCR). The exon 4 (122 bp) deletion resulted in a reading frame shift over the junction of exons 3-5 and a stop codon (tga) 17 bp downstream from exon 3. The translated truncated protein was associated with a total loss of the two-RING finger functional domain. Utilizing TaqMan real-time PCR with probes located across the junction of exons 3-4 or 3-5, we demonstrated an over-expression of E4SV/wild-type parkin ratio in the leukocytes of sporadic PD patients compared to age-, gender-, and race-matched controls (p<0.0005). A multivariate regression analysis demonstrated that the ratio of E4SV/wild-type parkin expression increased with age in PD patients, but this was not observed in the controls (p<0.0005). CONCLUSION The relative expression of E4SV/wild type parkin was increased in sporadic PD compared to healthy controls. Based on our observations, further functional studies to determine the pathophysiologic role of E4SV in sporadic PD patients will be of importance.
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Tow BPB, Chang PCC, Mitra AK, Tay BK, Wong MC. Comparing 2-year outcomes of anterior cruciate ligament reconstruction using either patella-tendon or semitendinosus-tendon autografts: a non-randomised prospective study. J Orthop Surg (Hong Kong) 2005; 13:139-46. [PMID: 16131675 DOI: 10.1177/230949900501300206] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
PURPOSE To compare the results of anterior cruciate ligament (ACL) reconstructions using either a patella-tendon autograft or a semitendinosus-tendon autograft. METHODS Based on surgeon experience and preference, 68 patients underwent ACL reconstruction using either a quadruple-strand semitendinosus autograft (n = 34) or a central one-third bone-patella tendon-bone autograft (n = 34). Each patient was assessed preoperatively and postoperatively at 3, 6, and 24 months using the International Knee Documentation Committee (IKDC) knee score, Biodex muscle strength and endurance testing, and the KT1000 instrumented arthrometer test of knee laxity to anterior translation. All assessments at the 2-year follow-up were performed by the same physician and physiotherapist. RESULTS While ACL reconstruction improved knee stability and IKDC knee scores significantly, there was no statistically significant difference between semitendinosus- and patella-tendon autograft reconstructions in terms of long-term knee score or laxity to anterior translation. Semitendinosus graft reconstruction was associated with less donor-site morbidity and hamstring weakness. Meniscectomy was associated with poorer long-term knee scores. CONCLUSION ACL reconstruction is associated with a significantly better IKDC knee score and laxity measurement at 2-year follow-up. However, we were unable to demonstrate a significantly better long-term outcome in knee score or laxity to anterior translation with either a patella-tendon autograft or a semitendinosus-tendon autograft.
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Tan EK, Yeo AP, Tan V, Pavanni R, Wong MC. Prescribing pattern in Parkinson's disease: are cost and efficacy overriding factors? Int J Clin Pract 2005; 59:511-4. [PMID: 15857344 DOI: 10.1111/j.1368-5031.2005.00426.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Information on prescribing pattern of antiparkinsonian medications and factors influencing neurologists' choice of such drugs are important considerations in evaluating healthcare cost of Parkinson's disease (PD). We surveyed neurologists' perceived factors influencing their choice of drugs and actual prescribing pattern in PD. Three hundred and six patients at a tertiary hospital, diagnosed with idiopathic PD and who were dispensed antiparkinsonian drugs during a 6-month period were randomly selected. Patient demographics, type and dose of medications were analysed. A questionnaire survey evaluating the factors influencing choice of medications was administered to neurologists who practiced at the institution. The study population had a mean age of 64.4 years (SD +/- 9.9 years), and more than 80% were at Hoehn & Yahr stage 2-3. 92.3% of the study population were receiving levodopa and monotherapy, with levodopa being the most common treatment regimen. Patients who were prescribed levodopa were significantly older and at a later stage of disease compared to those without levodopa (p < 0.05). Only 26.8% of patients were prescribed dopamine agonists. In the survey, the neurologists cited severity of symptoms, and patients' intolerance of side effects, and efficacy as the most important factors influencing their choice of drugs. However, the actual prescribing pattern revealed a strong positive correlation of drug usage with cost subsidy by the institution. While factors affecting drug usage in PD are well recognised, cost and efficacy of a drug appear to be overriding practical factors in influencing usage pattern in clinical practice.
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Tan EK, Zhao Y, Puong KY, Law HY, Chan LL, Yew K, Shen H, Chandran VR, Yuen Y, Pavanni R, Wong MC, Ng IS. Expanded FMR1 alleles are rare in idiopathic Parkinson?s disease. Neurogenetics 2004; 6:51-2. [PMID: 15742217 DOI: 10.1007/s10048-004-0200-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Tan HW, Ty A, Goh SGN, Wong MC, Hong A, Chuah KL. Pineal yolk sac tumour with a solid pattern: a case report in a Chinese adult man with Down's syndrome. J Clin Pathol 2004; 57:882-4. [PMID: 15280413 PMCID: PMC1770394 DOI: 10.1136/jcp.2004.016659] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Intracranial germ cell tumours are rare. The incidence of primary intracranial yolk sac tumour is even more uncommon, with only two reported cases being associated with Down's syndrome in the English literature. This report details the findings of yolk sac tumour in the pineal region affecting a 22 year old Chinese man with Down's syndrome. Histology revealed yolk sac tumour with only a solid pattern, potentially mimicking the more common germinoma in the pineal region. No other germ cell components were identified. This is the third report of intracranial yolk sac tumour manifesting in a patient with trisomy 21. The pathology of this tumour and its differential diagnoses are discussed.
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Kang KB, Wang TT, Woon CT, Cheah ST, Lim YK, Moore XL, Wong MC. Celecoxib enhances brain tumour cell radiosensitivity leading to massive tumour necrosis. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:S19-20. [PMID: 15651189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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See SJ, Pan A, Seah A, Teo J, Chan LL, Wong MC. Case reports of two biopsy-proven patients with Creutzfeldt-Jakob disease in Singapore. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:651-5. [PMID: 15531964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
INTRODUCTION Creutzfeldt-Jakob disease (CJD) is the most common transmissible human subacute spongiform encephalopathy. There is limited literature on CJD in Southeast Asia. We describe the clinical course and diagnostic evaluation of 2 Singapore patients with biopsy-proven CJD. CLINICAL PICTURE Two patients presented with non-specific symptoms such as withdrawal, forgetfulness, asthenia, giddiness and insomnia. Both patients had spontaneous myoclonic jerks and impairment of multiple neurologic systems (visual, pyramidal, cerebellar and neurocognitive systems). Magnetic resonance imaging and electroencephalography provided helpful supportive evidence. Diagnosis of CJD was established on brain biopsy. Histological features included spongioform degeneration, neuronal cell loss and astrocytosis. TREATMENT/OUTCOME Treatment remains palliative. Deterioration in their clinical condition was relentless, progressing to a totally dependent state within 10 to 12 months. CONCLUSION The early features of CJD can be varied and non-specific. It is important for physicians from different specialties to be cognisant of the clinical manifestations of CJD and the appearance of supportive and definitive investigations.
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Wong MC, Allison K, Yap LH, Peart F. The pedicled intercostal neurovascular island skin flap for lumbosacral trunk reconstruction. ACTA ACUST UNITED AC 2004; 57:520-4. [PMID: 15308398 DOI: 10.1016/j.bjps.2004.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2003] [Accepted: 03/29/2004] [Indexed: 11/18/2022]
Abstract
The pedicled intercostal neurovascular island flap is a useful flap due to its pedicle length, skin pedicle size and possibility for sensation. We present our experience of using this flap for lumbosacral trunk reconstruction in four patients.
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Tan EK, Zhao Y, Puong KY, Law HY, Chan LL, Yew K, Tan C, Shen H, Chandran VR, Teoh ML, Yih Y, Pavanni R, Wong MC, Ng IS. Fragile X premutation alleles in SCA, ET, and parkinsonism in an Asian cohort. Neurology 2004; 63:362-3. [PMID: 15277639 DOI: 10.1212/01.wnl.0000130199.57181.7b] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Among 367 subjects, the authors analyzed 167 patients with essential tremor, sporadic progressive cerebellar ataxia, multiple-system atrophy, and atypical parkinsonism and 200 healthy control subjects for FMR1 premutation alleles. None of the subjects carried alleles within the premutation range. These findings suggest that in the absence of other supportive clinical or imaging features, the cost-effectiveness of routine fragile X tremor/ataxia syndrome screening in this Asian cohort with movement disorders was low.
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Wilder-Smith E, Shen Y, Ng YK, Yu GX, Chew NK, Tan CT, Wong MC. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in a Chinese family: clinical, radiological and skin biopsy features. J Clin Neurosci 2004; 11:304-7. [PMID: 14975424 DOI: 10.1016/j.jocn.2003.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2003] [Accepted: 05/23/2003] [Indexed: 10/26/2022]
Abstract
We describe the clinical, radiological, genetic and skin biopsy findings of the first Chinese family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Of the 43-member family tree extending over three generations, eight had typical clinical features of CADASIL with recurrent ischemic stroke. In the three surviving affected family members, brain MRI showed extensive leukoaraiosis. Genotyping revealed heterozygous C to T mutation at nucleotide 406 in exon 3. Unusual clinical features were cerebellar infarction as a presenting complaint and a late age of onset with mild symptoms at age 69. A novel finding is the suggestion of a direct correlation between clinical disease severity and the quantity of ultrastructural pathognomonic granular osmophilic material (GOM) seen on skin biopsy.
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Lim WL, Xing H, Wong KH, Wong MC, Shao YM, Ng MH, Lee SS. The lack of epidemiological link between the HIV type 1 infections in Hong Kong and Mainland China. AIDS Res Hum Retroviruses 2004; 20:259-62. [PMID: 15117447 DOI: 10.1089/088922204322996473] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Blood samples were collected from 139 newly reported HIV-1 infections in Hong Kong over a 3-year period between 1999 and 2001, representing 22.8% of all reported cases. A majority of the patients were male (85.6%), Chinese (74%), and adult (97.1%) and acquired HIV-1 through sexual transmission (88.2%). The B and CRF01_AE were the major subtypes detected--49.6% and 44.6%, respectively. Over time, the frequency of CRF01_AE subtype increased, the B subtype decreased, and new subtypes of C (4) 2.8%, B' (1) 0.7%, and CRF07_BC (3) 2.2% emerged. The CRF01_AE subtype was commoner in female, Chinese, heterosexuals, and injection drug users whereas B subtype was commoner in male, white, and people with homosexual/bisexual contacts. There was no common source of infection from the analysis except a discernible cluster of Vietnamese injection drug users with the CRF01_AE subtype. The molecular findings did not suggest an epidemiological link between HIV infection in Hong Kong and Mainland China. Hong Kong's longstanding and extensive methadone treatment network may have contributed to the phenomenon.
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Tan EK, Chai A, Teo YY, Zhao Y, Tan C, Shen H, Chandran VR, Teoh ML, Yih Y, Pavanni R, Wong MC, Puvan K, Lo YL, Yap E. Alpha-synuclein haplotypes implicated in risk of Parkinson's disease. Neurology 2004; 62:128-31. [PMID: 14718715 DOI: 10.1212/01.wnl.0000101721.25345.dc] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors examined four- and six-loci haplotype constructs (from five single nucleotide polymorphisms and three microsatellite regions) of the alpha-synuclein gene in patients with Parkinson's disease (PD) and controls in an ethnic Chinese population. Logistic regression analysis demonstrated an association of NACP-Rep1 (p = 0.002) and L478 (p < 0.0001) with risk of PD after correction for the effects of age, sex, and the other polymorphic loci. Specific four-loci and six-loci haplotypes were significantly associated with an increased or decreased risk of PD.
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Tan EK, Tan C, Fook-Chong SMC, Lum SY, Chai A, Chung H, Shen H, Zhao Y, Teoh ML, Yih Y, Pavanni R, Chandran VR, Wong MC. Dose-dependent protective effect of coffee, tea, and smoking in Parkinson's disease: a study in ethnic Chinese. J Neurol Sci 2003; 216:163-7. [PMID: 14607318 DOI: 10.1016/j.jns.2003.07.006] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Few studies have examined the relationship of coffee and tea in Parkinson's disease (PD). The potential protective effect of coffee intake and risk of PD has not been studied in a Chinese population. There is a high prevalence of caffeine takers among Chinese in our population. OBJECTIVE We undertook a case control study to examine the relationship between coffee and tea drinking, cigarette smoking, and other enviromental factors and risk of PD among ethnic Chinese in our population. METHODS AND RESULTS 300 PD and 500 population controls were initially screened. Two hundred case control pairs matched for age, gender, and race were finally included in the analysis. Univariate analysis revealed significant association of PD with coffee drinking (p<0.0005), tea drinking (p=0.019), alcohol drinking (p=0.001), cigarette smoking (p<0.0005), and exposure to heavy metals (p=0.006). Conditional logistic regression analysis demonstrated that amount of coffee drunk (OR 0.787, 95%CI 0.664-0.932, p=0.006), amount of tea drunk (OR 0.724, 95%CI 0.559-0.937, p=0.014), number of cigarettes smoked (OR 0.384, 95%CI 0.204-0.722, p=0.003), history of heavy metal and toxin exposure (OR 11.837, 95%CI 1.075-130.366, p=0.044), and heart disease (OR 5.518, 95%CI 1.377-22.116, p=0.016) to be significant factors associated with PD. One unit of coffee and tea (3 cups/day for 10 years) would lead to a 22% and 28% risk reduction of PD. One unit of cigarette smoke (3 packs/day for 10 years) reduced the risk of PD by 62%. CONCLUSIONS We demonstrated a dose-dependent protective effect of PD in coffee and tea drinkers and smokers in an ethnic Chinese population. A history of exposure to heavy metals increased the risk of PD, supporting the multifactorial etiologies of the disease.
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Wong MC, Nandhra H, Gowrie BJ, Shah EF. A rare presentation of caecal adenocarcinoma. HOSPITAL MEDICINE 2003; 64:748-9. [PMID: 14702791 DOI: 10.12968/hosp.2003.64.12.2371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper describes an unusual case of caecal adenocarcinoma which had perforated through to the anterior abdominal wall. Colocutaneous fistula is an uncommon complication of colonic cancer which is more typically associated with sepsis and ischaemia of the bowel, inflammatory bowel disease and trauma. On rare occasions, as in this case, the colocutaneous fistula may be the initial presenting complaint.
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Wilder-Smith E, Tan EK, Law HY, Zhao Y, Ng I, Wong MC. Spinocerebellar ataxia type 3 presenting as an L-DOPA responsive dystonia phenotype in a Chinese family. J Neurol Sci 2003; 213:25-8. [PMID: 12873751 DOI: 10.1016/s0022-510x(03)00129-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The clinical spectrum of spinocerebellar ataxia 3 (SCA 3) disease is wide and varied. We describe a Chinese patient with a mutation at the SCA 3 locus with clinical features of levodopa-responsive dystonia. The family history was suggestive of being autosomally dominant. Levodopa responsiveness though rare has been described in families with features of parkinsonism. Noteworthy is the relatively late onset of disease (>40 years) possibly explained by the low number of affected alleles at 59, the usual range being from 62 to 86, with the lowest recorded number at 56. This expands the wide and varied phenotypic manifestations of SCA 3, and highlights the observation that features suggestive of levodopa-responsive dystonia (DRD) such as focal dystonia, gait difficulty with diurnal fluctuation of symptoms, and a marked response to low doses of levodopa can be presenting features of SCA 3. SCA 3 should be considered a differential diagnosis in adult patients who present with DRD phenotype and with a positive family history.
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Tan EK, Chan LL, Auchus AP, Wong MC. Reversible choreoathetosis in primary cerebral lymphoma: clinicoradiologic correlation. Eur Neurol 2003; 50:53-4. [PMID: 12824713 DOI: 10.1159/000070859] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tan EK, Chai A, Lum SY, Shen H, Tan C, Teoh ML, Yih Y, Wong MC, Zhao Y. Monoamine oxidase B polymorphism, cigarette smoking and risk of Parkinson's disease: a study in an Asian population. Am J Med Genet B Neuropsychiatr Genet 2003; 120B:58-62. [PMID: 12815741 DOI: 10.1002/ajmg.b.20035] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cigarette smoking is associated with reduced monoamine oxidase B (MAO B) activity. Polymorphisms of the MAO B gene may modify the relationship between smoking and Parkinson's Disease (PD). We examined the association of MAO B intron 13 G/A polymorphism and risk of PD, and the modulation of the polymorphism on smoking and PD in an Asian study population in Singapore. Two hundred and thirty PD patients (mean age 66.0 +/- 9.4 years, 63% men) and 241 age, gender, and race matched controls (mean age 64 +/- 9.2 years, 58.9% males) were studied. The frequency of G and A alleles in PD and controls was; 66/315 (21.0%) vs. 73/340 (21.5%) and 249/315 (79.0%) vs. 267/340 (78.5%). For women, the genotype frequency in PD and controls was; GG: 7/85 (8.2%) vs. 8/99 (8.1%); GA: 25/85 (29.4%) vs. 27/99 (27.3%); AA: 53/85 (62.4%) vs. 64/99 (64.6%). For men, allele frequency in PD and controls was; A: 118/145 (81.4%) vs. 112/142 (78.9%) and G: 27/145 (18.6%) vs. 30/142 (21.1%). The allele and genotype frequencies were not significantly different between young and late onset PD. The frequency of "ever" smokers in PD and controls was 31/230 (13.5%) vs. 52/241 (21.6%), P = 0.02. A stepwise logistic regression analysis did not reveal any interaction of smoking and the G allele and risk of PD. The MAO B G/A genotype frequency in our Asian population was quite different from Caucasians suggesting that ethnicity specific effects need to be considered in evaluating gene-environmental interaction.
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Tan EK, Chan LL, Wong MC. Levodopa-induced oromandibular dystonia in progressive supranuclear palsy. Clin Neurol Neurosurg 2003; 105:132-4. [PMID: 12691807 DOI: 10.1016/s0303-8467(02)00128-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Levodopa-induced dyskinesias have been reported in Parkinson's disease and multiple system atrophy. Cranial dystonias are rare in patients with progressive supranuclear palsy (PSP). In this report we describe an unusual case of reversible levodopa-induced Oromandibular dystonia (OMD) in a PSP patient to highlight the importance of recognizing this drug related complication in the management of PSP, and discuss the possible underlying pathophysiology.
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Tan EK, Ratnagopal P, Han SY, Wong MC. Piribedil and bromocriptine in Parkinson's disease: a single-blind crossover study. Acta Neurol Scand 2003; 107:202-6. [PMID: 12614313 DOI: 10.1034/j.1600-0404.2003.02104.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Clinicians switch from one dopamine agonist to another for various reasons. However, each change may inadvertently result in certain potential risks such as decreased medication efficacy or new side-effects. OBJECTIVE We evaluated the tolerability of a switch of bromocriptine to piribedil using two conversion ratios as a primary outcome measure, with motor function as a secondary outcome measure, in patients with mild to moderate Parkinson's disease (PD). METHODS Twenty consecutive patients with mild to moderate PD (Hoehn and Yahr, stage II-III) on treatment with stable doses of bromocriptine and levodopa were randomized to two groups of 10 patients each, to receive piribedil based on 1:5 or 1:10 conversion ratios. Blinded evaluations were performed: 1) United Parkinson's Diseased Rating Scale (UPDRS) scores both in 'on' and 'off', 2) Open-ended interviews for adverse events, 3) Epworth Sleepiness Scale, 4) Purdue Pegboard assessment during 'on' and 'off', 5) Hand-arm movement test during 'on' and 'off', and 6) Walking test during 'on' and 'off'. RESULTS Major adverse events included 'sleep attacks' in one patient and minor side-effects included giddiness, nausea, hallucinations, sleepiness and lethargy. However, these were mild and 19 (95%) of the 20 patients completed the study. There was a significant improvement in both the UPDRS 'off' total and motor scores at 1 month compared with baseline for the group on 1:10 ratio. The walking times during the 'off' state at 1 and 2 months were significantly better compared with baseline in the 1:5 group. There were otherwise no significant differences in the rating tests during both 'off' and 'on' states before and after the bromocriptine switch. CONCLUSIONS We demonstrated that patients with mild to moderate PD who were on relatively low doses of bromocriptine can be safely switched to piribedil based on a conversion ratio of either 1:5 or 1:10. However, the higher conversion ratio has to be carried out with caution in patients with daytime somnolence.
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Tan EK, Chan LL, Lum SY, Koh P, Han SY, Fook-Chong SMC, Lo YL, Pavanni R, Wong MC, Lim SH. Is hypertension associated with hemifacial spasm? Neurology 2003; 60:343-4. [PMID: 12552060 DOI: 10.1212/01.wnl.0000042786.28267.b2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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