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Bhidayasiri R, Phokaewvarangkul O, Lim TT, Pal PK, Watanabe H, Cho JW, Shang HF. Neurological perspectives should be integrated into the management of tardive dyskinesia - expert opinion and proposed educational initiatives in Asia. J Mov Disord 2024:jmd.24068. [PMID: 38600683 DOI: 10.14802/jmd.24068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 04/11/2024] [Indexed: 04/12/2024] Open
Affiliation(s)
- Roongroj Bhidayasiri
- Chulalongkorn Centre of Excellence for Parkinson's Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
- The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
| | - Onanong Phokaewvarangkul
- Chulalongkorn Centre of Excellence for Parkinson's Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Thien Thien Lim
- Neurology Unit, Island Hospital, Georgetown, Penang, Malaysia
| | - Pramod Kumar Pal
- National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Hirohisa Watanabe
- Department of Neurology, Fujita Health University, Aichi, Toyoake, Japan
| | - Jin Whan Cho
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, South Korea
| | - Hui-Fang Shang
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
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Bhidayasiri R, Phokaewvarangkul O, Shang HF, Lim TT, Cho JW, Pal PK, Watanabe H. Tardive dyskinesia in Asia- current clinical practice and the role of neurologists in the care pathway. Front Neurol 2024; 15:1356761. [PMID: 38419696 PMCID: PMC10901179 DOI: 10.3389/fneur.2024.1356761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 01/29/2024] [Indexed: 03/02/2024] Open
Abstract
Tardive dyskinesia (TD) is a movement disorder that can arise as a side effect of treatment with dopamine receptor-blocking agents (DRBAs), including antipsychotic drugs (APDs) used to manage psychotic illnesses. Second-generation APDs (SGAs) are often preferred to first-generation drugs due to their lower propensity to cause TD, however many SGAs-treated patients still develop the condition. Although TD is a global health concern, evidence regarding the occurrence of TD and how it is managed in Asian countries is currently limited. This article reports the results of a systematic review of the published literature on TD focusing on its prevalence, types of patients, knowledge of the condition, causative factors, and usual treatment pathways in clinical practice in Asian countries. Epidemiological data suggest that the prevalence of TD is increasing globally due to an overall rise in APD use, contributing factors being polypharmacy with multiple APDs, the use of higher than necessary doses, and off-label use for non-psychotic indications. Although exact prevalence figures for TD in Asian countries are difficult to define, there is a similar pattern of rising APD use which will result in increasing numbers of TD patients in this region. These issues need to be addressed and strategies developed to minimize TD risk and manage this disabling condition which impacts patients' quality of life and daily functioning. To date, both research into TD has been predominantly psychiatry focused and the perspectives from neurologists regarding the clinical management of this challenging condition are scarce. However, neurologists have an essential role in managing the movement disorders manifestations that characterize TD. Optimum management of TD, therefore, should ideally involve collaboration between psychiatrists and neurologists in joint care pathways, wherever practical. Collaborative pathways are proposed in this article, and the challenges that will need to be addressed in Asian countries to improve the care of people with TD are highlighted, with a focus on the neurologist's viewpoint and the implications for the management of TD globally.
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Affiliation(s)
- Roongroj Bhidayasiri
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
- The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
| | - Onanong Phokaewvarangkul
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Hui-Fang Shang
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Thien Thien Lim
- Neurology Unit, Island Hospital, Georgetown, Penang, Malaysia
| | - Jin Whan Cho
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Hirohisa Watanabe
- Department of Neurology, Fujita Health University, Toyoake, Aichi, Japan
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Lim TT, Por CY, Beh YY, Schee JP, Tan AH. Treatment of startle and related disorders. Clin Park Relat Disord 2023; 9:100218. [PMID: 37808566 PMCID: PMC10556813 DOI: 10.1016/j.prdoa.2023.100218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/04/2023] [Accepted: 09/15/2023] [Indexed: 10/10/2023] Open
Affiliation(s)
| | - Chia Yin Por
- Department of Medicine, Penang General Hospital, Penang, Malaysia
| | - Yuan Ye Beh
- Department of Medicine, Penang General Hospital, Penang, Malaysia
| | - Jie Ping Schee
- Faculty of Medicine (Divisions of Neurology), University of Malaya, Malaysia
| | - Ai Huey Tan
- Faculty of Medicine (Divisions of Neurology), University of Malaya, Malaysia
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Por CY, Lim TT, Chee YC, Raymond AA. A Paradoxical Phenomenon: Hemichorea-Hemiballismus Resolution After Stroke in Moyamoya Disease. J Clin Neurol 2023; 19:410-412. [PMID: 37417437 DOI: 10.3988/jcn.2023.0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/02/2023] [Accepted: 03/15/2023] [Indexed: 07/08/2023] Open
Affiliation(s)
| | | | - Yong Chuan Chee
- Department of Medicine (Neurology), School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
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Bhidayasiri R, Sringean J, Van Le T, Lim TT, Navuth C, Phoumindr A, Aye YM, Phumphid S, Vorachit S, Veasna K, Ibrahim NM, Thit WM, Rosales RL, Le M, Tran NT. Movement disorders in Indochina: Resource challenges and future solutions. J Neural Transm (Vienna) 2023:10.1007/s00702-023-02662-1. [PMID: 37306791 DOI: 10.1007/s00702-023-02662-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/02/2023] [Indexed: 06/13/2023]
Abstract
Movement disorders are a major cause of disability worldwide and their increasing prevalence predicts a substantial future burden of care. Impactful patient care requires availability of, and accessibility to, effective medications, knowledge, and disease awareness among both medical professionals and patients, driven by skilled personnel to harness and manage resources. The highest burden of movement disorders is in low-to-middle income countries where resources are often limited and infrastructure is insufficient to meet growing demands. This article focuses on the specific challenges faced in the management and delivery of care for movement disorders in Indochina, the mainland region of Southeast Asia comprising the neighboring countries of Cambodia, Laos, Malaysia, Myanmar, Thailand, and Vietnam. The first Indochina Movement Disorders Conference was held in August 2022 in Ho Chi Minh City, Vietnam, to provide a platform to better understand the situation in the region. Future management of movement disorders in Indochina will require progressive adaptation of existing practices to reflect modern approaches to care delivery. Digital technologies offer an opportunity to strengthen these processes and address the challenges identified in the region. Ultimately, a long-term collaborative approach by regional healthcare providers is key.
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Affiliation(s)
- Roongroj Bhidayasiri
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand.
- The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand.
| | - Jirada Sringean
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Tuan Van Le
- Neurology Department, University Medical Centre, University of Medicine and Pharmacy of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Thien Thien Lim
- Neurology Unit, Island Hospital, Georgetown, Penang, Malaysia
| | - Chum Navuth
- Department of Neurology, Khmer-Soviet Friendship Hospital, Phnom Penh, Cambodia
| | - Appasone Phoumindr
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
- Sethathirath Hospital, University of Health Sciences, Vientiane, Laos
| | - Yin Minn Aye
- Department of Neurology, Yangon General Hospital, University of Medicine, Yangon, Myanmar
| | - Saisamorn Phumphid
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Somchit Vorachit
- Sethathirath Hospital, University of Health Sciences, Vientiane, Laos
| | - Keo Veasna
- Department of Neurology, Khmer-Soviet Friendship Hospital, Phnom Penh, Cambodia
| | - Norlinah Mohamed Ibrahim
- Faculty of Medicine, Neurology Unit, Department of Medicine, Hospital Canselor Tuanku Muhriz, UKM Medical Centre, Kuala Lumpur, Malaysia
| | - Win Min Thit
- Department of Neurology, Yangon General Hospital, University of Medicine, Yangon, Myanmar
| | - Raymond L Rosales
- Department of Neurology and Psychiatry, Neuroscience Institute, University of Santo Tomas Hospital, Manila, Philippines
| | - Minh Le
- Neurology Department, University Medical Centre, University of Medicine and Pharmacy of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Ngoc Tai Tran
- Neurology Department, University Medical Centre, University of Medicine and Pharmacy of Ho Chi Minh City, Ho Chi Minh City, Vietnam
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Ng WK, Philip AZ, Lim TT, Wong M, Goh EL, Tengku Ismail TS, Goh TH. Anti-hypertensive prescription practices in private hospitals in Malaysia: a prospective, non-interventional, observational study. Med J Malaysia 2023; 78:350-356. [PMID: 37271845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
INTRODUCTION In managing hypertension, monotherapy and sometimes a combination of more than one agent are used to achieve blood pressure (BP) control. The objective of this prospective, observational, multi-centre study was to assess the level of BP control in patients receiving one or more anti-hypertensive drugs in private medical centres in Malaysia according to the treatment regimens (monotherapy, free drug combinations and single pill combinations). MATERIALS AND METHODS Data were collected through medical records and interview sessions with patients on current pharmacotherapy for hypertension management at baseline and 2-3 months later. Results are expressed as mean ± SD for continuous data and as frequencies and percentages for categorical data. RESULTS Among 182 recruited patients, 89 (49%) achieved BP control by the end of the study. Majority (62/89) patients were on single-pill (monotherapy or SPC) antihypertensives. Majority (63/89) required more than two antihypertensives to achieve BP control. CONCLUSION Both SPC and free drug combination antihypertensives reduced BPs, but physicians preferred SPC to improve BP control and increase treatment compliance.
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Affiliation(s)
- W K Ng
- Pantai Hospital Kuala Lumpur, Kuala Lumpur, Malaysia
| | - A Z Philip
- Mahkota Medical Centre, Melaka, Malaysia
| | - T T Lim
- Island Hospital, Penang, Malaysia
| | - M Wong
- Sunway Medical Centre, Selangor, Malaysia
| | - E L Goh
- Loh Guan Lye Hospital, Penang, Malaysia
| | | | - T H Goh
- Loh Guan Lye Hospital, Penang, Malaysia
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Tay YW, Tan AH, Lim JL, Lohmann K, Ibrahim KA, Abdul Aziz Z, Chin YT, Mawardi AS, Lim TT, Looi I, Chia YK, Ooi JCE, Cheah WK, Dy Closas AMF, Lit LC, Hor JW, Toh TS, Muthusamy KA, Bauer P, Skrahin V, Rolfs A, Klein C, Ahmad-Annuar A, Lim SY. Genetic study of early-onset Parkinson's disease in the Malaysian population. Parkinsonism Relat Disord 2023; 111:105399. [PMID: 37209484 DOI: 10.1016/j.parkreldis.2023.105399] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/17/2023] [Accepted: 04/11/2023] [Indexed: 05/22/2023]
Abstract
BACKGROUND About 5-10% of Parkinson's disease (PD) cases are early onset (EOPD), with several genes implicated, including GBA1, PRKN, PINK1, and SNCA. The spectrum and frequency of mutations vary across populations and globally diverse studies are crucial to comprehensively understand the genetic architecture of PD. The ancestral diversity of Southeast Asians offers opportunities to uncover a rich PD genetics landscape, and identify common regional mutations and new pathogenic variants. OBJECTIVES This study aimed to investigate the genetic architecture of EOPD in a multi-ethnic Malaysian cohort. METHODS 161 index patients with PD onset ≤50 years were recruited from multiple centers across Malaysia. A two-step approach to genetic testing was used, combining a next-generation sequencing-based PD gene panel and multiplex ligation-dependent probe amplification (MLPA). RESULTS Thirty-five patients (21.7%) carried pathogenic or likely pathogenic variants involving (in decreasing order of frequency): GBA1, PRKN, PINK1, DJ-1, LRRK2, and ATP13A2. Pathogenic/likely pathogenic variants in GBA1 were identified in thirteen patients (8.1%), and were also commonly found in PRKN and PINK1 (11/161 = 6.8% and 6/161 = 3.7%, respectively). The overall detection rate was even higher in those with familial history (48.5%) or age of diagnosis ≤40 years (34.8%). PRKN exon 7 deletion and the PINK1 p.Leu347Pro variant appear to be common among Malay patients. Many novel variants were found across the PD-related genes. CONCLUSIONS This study provides novel insights into the genetic architecture of EOPD in Southeast Asians, expands the genetic spectrum in PD-related genes, and highlights the importance of diversifying PD genetic research to include under-represented populations.
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Affiliation(s)
- Yi Wen Tay
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Ai Huey Tan
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, University of Malaya, Kuala Lumpur, Malaysia; Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Jia Lun Lim
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Katja Lohmann
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany
| | - Khairul Azmi Ibrahim
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | - Zariah Abdul Aziz
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | - Yen Theng Chin
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | | | | | - Irene Looi
- Department of Neurology, Seberang Jaya Hospital, Penang, Malaysia
| | - Yuen Kang Chia
- Department of Neurology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - Joshua Chin Ern Ooi
- Department of Neurology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - Wee Kooi Cheah
- Department of Geriatrics, Taiping Hospital, Taiping, Malaysia
| | - Alfand Marl F Dy Closas
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, University of Malaya, Kuala Lumpur, Malaysia; Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lei Cheng Lit
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Jia Wei Hor
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, University of Malaya, Kuala Lumpur, Malaysia; Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Tzi Shin Toh
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, University of Malaya, Kuala Lumpur, Malaysia; Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kalai Arasu Muthusamy
- Division of Neurosurgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Peter Bauer
- Centogene GmbH, Am Strande 7, 18057, Rostock, Germany
| | - Volha Skrahin
- Centogene GmbH, Am Strande 7, 18057, Rostock, Germany; Arcensus, Goethestrasse 20, 18055, Rostock, Germany
| | - Arndt Rolfs
- Centogene GmbH, Am Strande 7, 18057, Rostock, Germany; Arcensus, Goethestrasse 20, 18055, Rostock, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany.
| | - Azlina Ahmad-Annuar
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| | - Shen-Yang Lim
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, University of Malaya, Kuala Lumpur, Malaysia; Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Fong SL, Dy Closas AMF, Lim TT, Lean PL, Loh EC, Lim SY, Tan AH. From parasomnia to agrypnia excitata - An illustrative case on diagnostic approach. Parkinsonism Relat Disord 2023; 109:105332. [PMID: 36948111 DOI: 10.1016/j.parkreldis.2023.105332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/10/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023]
Abstract
The diagnostic approach to sleep-related movements disorders is seldom discussed. We report a case of fatal familial insomnia who initially presented with persistent limb movements in sleep, which later progressed to a state of agrypnia excitata. Here, the evaluation of abnormal movements in sleep is discussed using a step-by-step diagnostic approach. Although no cure is available for fatal familial insomnia, prompt recognition of this condition is important to facilitate proper management, including the involvement of interdisciplinary neuropalliative care.
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Affiliation(s)
- Si-Lei Fong
- Division of Neurology, Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Alfand Marl F Dy Closas
- Division of Neurology, Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | | | - Phooi Leng Lean
- Department of Medicine, Seberang Jaya Hospital, Penang, Malaysia
| | - Ee Chin Loh
- Division of Palliative Medicine, Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Shen-Yang Lim
- Division of Neurology, Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Ai Huey Tan
- Division of Neurology, Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
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Lim TT, Tan K, Eow GB, Bhidayasiri R. A South East Asian perspective of neuropsychiatric startle syndromes of latah. Parkinsonism Relat Disord 2022; 95:138-142. [DOI: 10.1016/j.parkreldis.2022.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 10/19/2022]
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Lim JL, Lohmann K, Tan AH, Tay YW, Ibrahim KA, Abdul Aziz Z, Mawardi AS, Puvanarajah SD, Lim TT, Looi I, Ooi JCE, Chia YK, Muthusamy KA, Bauer P, Rolfs A, Klein C, Ahmad-Annuar A, Lim SY. Glucocerebrosidase (GBA) gene variants in a multi-ethnic Asian cohort with Parkinson's disease: mutational spectrum and clinical features. J Neural Transm (Vienna) 2021; 129:37-48. [PMID: 34779914 DOI: 10.1007/s00702-021-02421-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/17/2021] [Indexed: 02/07/2023]
Abstract
GBA variants are associated with increased risk and earlier onset of Parkinson's disease (PD), and more rapid disease progression especially with "severe" variants typified by p.L483P. GBA mutation screening studies from South-East Asia, with > 650 million inhabitants of diverse ancestries, are very limited. We investigated the spectrum of GBA variants, and associated clinico-demographic features, in a multi-ethnic PD cohort in Malaysia. Patients (n = 496) were recruited from seven centres, primarily of Chinese (45%), Malay (37%), and Indian (13%) ethnicities. All GBA coding exons were screened using a next-generation sequencing-based PD gene panel and verified with Sanger sequencing. We identified 14 heterozygous GBA alleles consisting of altogether 17 missense variants (8 classified as pathogenic or likely pathogenic for PD) in 25 (5.0%) patients, with a substantially higher yield among early (< 50 years) vs. late-onset patients across all three ethnicities (9.1-13.2% vs. 1.0-3.2%). The most common variant was p.L483P (including RecNciI, n = 11, 2.2%), detected in all three ethnicities. Three novel variants/recombinant alleles of uncertain significance were found; p.P71L, p.L411P, and p.L15S(;)S16G(;)I20V. The common European risk variants, p.E365K, p.T408M, and p.N409S, were not detected. A severe disease course was noted in the majority of GBA-variant carriers, across a range of detected variants. We report a potentially novel observation of spine posture abnormalities in GBA-variant carriers. This represents the largest study on GBA variation from South-East Asia, and highlights that these populations, especially those with EOPD, would be relevant for studies including clinical trials targeting GBA pathways.
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Affiliation(s)
- Jia Lun Lim
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,The Mah Pooi Soo and Tan Chin Nam Centre for Parkinson's and Related Disorders, University of Malaya, Kuala Lumpur, Malaysia
| | - Katja Lohmann
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany
| | - Ai Huey Tan
- The Mah Pooi Soo and Tan Chin Nam Centre for Parkinson's and Related Disorders, University of Malaya, Kuala Lumpur, Malaysia.,Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yi Wen Tay
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,The Mah Pooi Soo and Tan Chin Nam Centre for Parkinson's and Related Disorders, University of Malaya, Kuala Lumpur, Malaysia
| | - Khairul Azmi Ibrahim
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | - Zariah Abdul Aziz
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | | | | | - Thien Thien Lim
- Island Hospital, Penang, Malaysia.,Penang General Hospital, Penang, Malaysia
| | - Irene Looi
- Department of Medicine and Clinical Research Centre, Hospital Seberang Jaya, Penang, Malaysia
| | - Joshua Chin Ern Ooi
- Department of Neurology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - Yuen Kang Chia
- Department of Neurology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - Kalai Arasu Muthusamy
- Division of Neurosurgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Peter Bauer
- Centogene AG, Am Strande 7, 18057, Rostock, Germany
| | - Arndt Rolfs
- Centogene AG, Am Strande 7, 18057, Rostock, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany
| | - Azlina Ahmad-Annuar
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| | - Shen-Yang Lim
- The Mah Pooi Soo and Tan Chin Nam Centre for Parkinson's and Related Disorders, University of Malaya, Kuala Lumpur, Malaysia. .,Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Chee YC, Lim TT, Ong BH. Adult-Onset Satoyoshi Syndrome and Axial Spondyloarthritis. J Clin Neurol 2021; 17:593-595. [PMID: 34595874 PMCID: PMC8490904 DOI: 10.3988/jcn.2021.17.4.593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/08/2021] [Accepted: 06/08/2021] [Indexed: 12/02/2022] Open
Affiliation(s)
- Yong Chuan Chee
- Department of Medicine (Neurology), School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
| | - Thien Thien Lim
- Neurology Unit, Island Hospital, Georgetown, Penang, Malaysia
| | - Beng Hooi Ong
- Neurology Unit, Kedah Medical Centre, Alor Setar, Kedah, Malaysia
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12
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Lim JL, Ng EY, Lim SY, Tan AH, Abdul-Aziz Z, Ibrahim KA, Gopalai AA, Tay YW, Vijayanathan Y, Toh TS, Lim SK, Bee PC, Puvanarajah SD, Viswanathan S, Looi I, Lim TT, Eow GB, Cheah WK, Tan EK, Ahmad-Annuar A. Association study of MCCC1/LAMP3 and DGKQ variants with Parkinson's disease in patients of Malay ancestry. Neurol Sci 2021; 42:4203-4207. [PMID: 33559030 DOI: 10.1007/s10072-021-05056-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 01/11/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND Genome-wide association studies (GWAS) have shown that variants in the 3-methylcrotonyl-CoA carboxylase (MCCC1)/lysosome-associated membrane protein 3 (LAMP3) loci (rs10513789, rs12637471, rs12493050) reduce the risk of Parkinson's disease (PD) in Caucasians, Chinese and Ashkenazi-Jews while the rs11248060 variant in the diacylglycerol kinase theta (DGKQ) gene increases the risk of PD in Caucasian and Han Chinese cohorts. However, their roles in Malays are unknown. Therefore, this study aims to investigate the association of these variants with the risk of PD in individuals of Malay ancestry. METHODS A total of 1114 subjects comprising of 536 PD patients and 578 healthy controls of Malay ancestry were recruited and genotyped using Taqman® allelic discrimination assays. RESULTS The G allele of rs10513789 (OR = 0.83, p = 0.001) and A allele of rs12637471 (OR = 0.79, p = 0.007) in the MCCC1/LAMP3 locus were associated with a protective effect against developing PD in the Malay population. A recessive model of penetrance showed a protective effect of the GG genotype for rs10513789 and the AA genotype for rs12637471. No association with PD was found with the other MCCC1/LAMP3 rs12493050 variant or with the DGKQ (rs11248060) variant. No significant associations were found between the four variants with the age at PD diagnosis. CONCLUSION MCCC1/LAMP3 variants rs10513789 and rs12637471 protect against PD in the Malay population.
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Affiliation(s)
- Jia Lun Lim
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Ebonne Yulin Ng
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, Singapore
| | - Shen-Yang Lim
- Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Ai Huey Tan
- Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- The Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Zariah Abdul-Aziz
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | - Khairul Azmi Ibrahim
- Department of Medicine, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia
| | - Aroma Agape Gopalai
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yi Wen Tay
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | | | - Tzi Shin Toh
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Soo Kun Lim
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Ping-Chong Bee
- Division of Haematology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | - Irene Looi
- Department of Medicine and Clinical Research Centre, Hospital Seberang Jaya, Penang, Malaysia
| | | | - Gaik Bee Eow
- Department of Neurology, Hospital Pulau Pinang, Penang, Malaysia
| | - Wee Kooi Cheah
- Department of Medicine, Hospital Taiping, Taiping, Perak, Malaysia
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Academia, 20 College Road, Level 4, Singapore, 169856, Singapore.
- Duke-NUS Graduate Medical School, Singapore, Singapore.
| | - Azlina Ahmad-Annuar
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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Hong WC, Hong EQW, Eow GB, Lim TT, Thankamony S, Rohani S. Essential tremor: A study in a tertiary hospital in Penang, Malaysia. J Neurol Sci 2021. [DOI: 10.1016/j.jns.2021.119535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Miyasaki JM, Lim TT, Bhidayasiri R. Editorial: Inclusion, equity, diversity and social justice in movement disorders research. Parkinsonism Relat Disord 2021; 85:114-116. [PMID: 33840573 DOI: 10.1016/j.parkreldis.2021.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/08/2021] [Accepted: 03/20/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Janis M Miyasaki
- Department of Medicine, Division Neurology, University of Alberta, Edmonton, Canada.
| | | | - Roongroj Bhidayasiri
- Chulalongkorn Centre of Excellence for Parkinson's Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand; The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
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Bhidayasiri R, Panyakaew P, Trenkwalder C, Jeon B, Hattori N, Jagota P, Wu YR, Moro E, Lim SY, Shang H, Rosales R, Lee JY, Thit WM, Tan EK, Lim TT, Tran NT, Binh NT, Phoumindr A, Boonmongkol T, Phokaewvarangkul O, Thongchuam Y, Vorachit S, Plengsri R, Chokpatcharavate M, Fernandez HH. Delivering patient-centered care in Parkinson's disease: Challenges and consensus from an international panel. Parkinsonism Relat Disord 2020; 72:82-87. [PMID: 32146380 DOI: 10.1016/j.parkreldis.2020.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/20/2020] [Accepted: 02/22/2020] [Indexed: 02/05/2023]
Abstract
An international panel of movement disorders specialists explored the views and perceptions of people with Parkinson's disease (PD) about their condition and its treatment, including the potential mismatch between the clinician's view of the patient's condition and their own view of what aspects of the disease most affect their daily lives. The initiative was focused on Asian countries, so participants comprised experts in the management of PD from key centers in Asia, with additional insight provided by European and the North American movement disorders experts. Analysis of peer-reviewed publications on patient perceptions of PD and the factors that they consider important to their wellbeing identified several contributing factors to the mismatch of views, including gaps in knowledge of PD and its treatment, an understanding of the clinical heterogeneity of PD, and the importance of a multidisciplinary approach to patient care. The faculty proposed options to bridge these gaps to ensure that PD patients receive the personalized treatment they need to achieve the best possible outcomes. It was considered essential to improve patient knowledge about PD and its treatment, as well as increasing the awareness of clinicians of PD heterogeneity in presentation and treatment response. A multidisciplinary and shared-care approach to PD was needed alongside the use of patient-centered outcome measures in clinical trials and clinical practice to better capture the patient experience and improve the delivery of individualized therapy.
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Affiliation(s)
- Roongroj Bhidayasiri
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand.
| | - Pattamon Panyakaew
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Claudia Trenkwalder
- Department of Neurosurgery, University Medical Centre Goettingen, Paracelsus-Elena Hospital, Kassel, Germany
| | - Beomseok Jeon
- Movement Disorder Centre at Seoul National University Hospital, Seoul, South Korea
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Priya Jagota
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Yih-Ru Wu
- Department of Neurology, Chang-Gung Memorial Hospital, Linkou Medical Centre and Chang-Gung University College of Medicine, Taipei, Taiwan
| | - Elena Moro
- Movement Disorder Centre, Centre Hospitalier Universitaire (CHU) of Grenoble, Grenoble Alpes University, INSERM U1216, France
| | - Shen-Yang Lim
- Division of Neurology, Department of Medicine and the Mah Pooi Soo and Tan Chin Nam Centre for Parkinson's and Related Disorders, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Huifang Shang
- Department of Neurology, West China Hospital, Sichuan University, China
| | - Raymond Rosales
- Neuroscience Institute, Department of Neurology and Psychiatry, University of Santo Tomas Hospital, Manila, Philippines
| | - Jee-Young Lee
- Department of Neurology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center & Seoul National University College of Medicine, Seoul, South Korea
| | - Win Min Thit
- Department of Neurology, University of Medicine, Yangon General Hospital, Yangon, Myanmar
| | - Eng-King Tan
- National Neuroscience Institute, DUKE NUS Medical School, Singapore
| | | | - Ngoc Tai Tran
- Movement Disorder Unit, Neurology Department, University Medical Centre, Ho Chi Minh City University of Medicine and Pharmacy, Ho Chi Minh, Viet Nam
| | - Nguyen Thanh Binh
- Department of Neurology, Hanoi Medical University and National Geriatric Hospital, Hanoi, Viet Nam
| | | | - Thanatat Boonmongkol
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Onanong Phokaewvarangkul
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Yuwadee Thongchuam
- Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | | | - Rachaneewan Plengsri
- Chulalongkorn Parkinson Patients' Support Group, Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Bangkok, Thailand
| | - Marisa Chokpatcharavate
- Chulalongkorn Parkinson Patients' Support Group, Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Bangkok, Thailand
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Gopalai AA, Lim JL, Li H, Zhao Y, Lim TT, Eow GB, Puvanarajah S, Viswanathan S, Norlinah MI, Abdul Aziz Z, Lim SK, Tan CT, Tan AH, Lim S, Tan E, Ahmad Annuar A. LRRK2 N551K and R1398H variants are protective in Malays and Chinese in Malaysia: A case-control association study for Parkinson's disease. Mol Genet Genomic Med 2019; 7:e604. [PMID: 31487119 PMCID: PMC6825847 DOI: 10.1002/mgg3.604] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/06/2019] [Accepted: 01/09/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The LRRK2 gene is associated with Parkinson's disease (PD) as a number of mutations within the gene have been shown to be susceptibility factors. Studies on various global populations have determined that mutations such as G2019S, G2385R, and R1628P in LRRK2 increase the risk of developing PD while the N551K-R1398H haplotype is associated with conferring protection against developing PD. Here we report a study looking at the N551K and R1398H variants for the first time in the Malaysian population. METHODS Cases (523) which conformed to the United Kingdom PD Brain Bank Criteria for PD were recruited through trained neurologists and age- and ethnically matched controls (491) were individuals free of any neurological disorder. The N551K and R1398H mutations were genotyped using the Taqman SNP genotyping assay. RESULTS A significant protective association for N551K was found in those of Malay ancestry, with a protective trend seen for R1398H. A meta-analysis of Chinese individuals in this cohort with other published cohorts of Chinese ancestry indicated a significant protective role for N551K and R1398H. CONCLUSION This study reports that the N551K-R1398H haplotype is also relevant to the Malaysian population, with a significant protective effect found in those of Malay and Chinese ancestries.
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Affiliation(s)
- Aroma Agape Gopalai
- Faculty of Medicine, Department of Biomedical ScienceUniversity of MalayaKuala LumpurMalaysia
| | - Jia Lun Lim
- Faculty of Medicine, Department of Biomedical ScienceUniversity of MalayaKuala LumpurMalaysia
| | - Hui‐Hua Li
- Health Services ResearchSingapore General HospitalSingaporeSingapore
- Centre for Quantitative MedicineDuke‐NUS Medical SchoolSingaporeSingapore
| | - Yi Zhao
- Department of Clinical Translational ResearchSingapore General HospitalSingaporeSingapore
| | | | - Gaik B. Eow
- Department of NeurologyHospital Pulau PinangPenangMalaysia
| | | | | | | | - Zariah Abdul Aziz
- Department of MedicineHospital Sultanah Nur ZahirahKuala TerengganuMalaysia
| | - Soo Kun Lim
- Faculty of Medicine, Department of MedicineUniversity of MalayaKuala LumpurMalaysia
| | - Chong Tin Tan
- Faculty of Medicine, Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related DisordersUniversity of MalayaKuala LumpurMalaysia
| | - Ai Huey Tan
- Faculty of Medicine, Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related DisordersUniversity of MalayaKuala LumpurMalaysia
| | - Shen‐Yang Lim
- Faculty of Medicine, Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related DisordersUniversity of MalayaKuala LumpurMalaysia
| | - Eng‐King Tan
- Department of NeurologySingapore General HospitalSingaporeSingapore
- National Neuroscience Institute and Duke‐NUS Graduate Medical SchoolSingaporeSingapore
| | - Azlina Ahmad Annuar
- Faculty of Medicine, Department of Biomedical ScienceUniversity of MalayaKuala LumpurMalaysia
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Bhidayasiri R, Rattanachaisit W, Phokaewvarangkul O, Lim TT, Fernandez HH. Exploring bedside clinical features of parkinsonism: A focus on differential diagnosis. Parkinsonism Relat Disord 2018; 59:74-81. [PMID: 30502095 DOI: 10.1016/j.parkreldis.2018.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/29/2018] [Accepted: 11/04/2018] [Indexed: 12/12/2022]
Abstract
The proper diagnosis of parkinsonian disorders usually involves three steps: identifying core features of parkinsonism; excluding other causes; and collating supportive evidence based on clinical signs or investigations. While the recognition of cardinal parkinsonian features is usually straightforward, the appreciation of clinical features suggestive of specific parkinsonian disorders can be challenging, and often requires greater experience and skills. In this review, we outline the clinical features that are relevant to the differential diagnosis of common neurodegenerative parkinsonian disorders, including Parkinson's disease, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration. We aim to make this process relatable to clinicians-in-practice, therefore, have categorised the list of clinical features into groups according to the typical sequence on how clinicians would elicit them during the examination, starting with observation of facial expression and clinical signs of the face, spotting eye movement abnormalities, examination of tremors and jerky limb movements, and finally, examination of posture and gait dysfunction. This review is not intended to be comprehensive. Rather, we have focused on the most common clinical signs that are potentially key to making the correct diagnosis and those that do not require special skills or training for interpretation. Evidence is also provided, where available, such as diagnostic criteria, consensus statements, clinicopathological studies or large multi-centre registries. Pitfalls are also discussed when relevant to the diagnosis. While no clinical signs are pathognomonic for certain parkinsonian disorders, certain clinical clues may assist in narrowing a differential diagnosis and tailoring focused investigations for the individual patient.
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Affiliation(s)
- Roongroj Bhidayasiri
- Chulalongkorn Center of Excellence for Parkinson's Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand; Department of Neurology, Juntendo University, Tokyo, Japan.
| | - Watchara Rattanachaisit
- Chulalongkorn Center of Excellence for Parkinson's Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Onanong Phokaewvarangkul
- Chulalongkorn Center of Excellence for Parkinson's Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | | | - Hubert H Fernandez
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, OH, USA
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Abstract
PURPOSE OF REVIEW To provide an overview of paraneoplastic autoimmune disorders presenting with various movement disorders. RECENT FINDINGS The spectrum of paraneoplastic autoimmune disorders has been expanding with the discovery of new antibodies against cell surface and intracellular antigens. Many of these paraneoplastic autoimmune disorders manifest as a form of movement disorder. With the discovery of new neuronal antibodies, an increasing number of idiopathic or neurodegenerative movement disorders are now being reclassified as immune-mediated movement disorders. These include anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis which may present with orolingual facial dyskinesia and stereotyped movements, CRMP-5 IgG presenting with chorea, anti-Yo paraneoplastic cerebellar degeneration presenting with ataxia, anti-VGKC complex (Caspr2 antibodies) neuromyotonia, opsoclonus-myoclonus-ataxia syndrome, and muscle rigidity and episodic spasms (amphiphysin, glutamic acid decarboxylase, glycine receptor, GABA(A)-receptor associated protein antibodies) in stiff-person syndrome. SUMMARY Movement disorders may be a presentation for paraneoplastic autoimmune disorders. Recognition of these disorders and their common phenomenology is important because it may lead to the discovery of an occult malignancy.
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Affiliation(s)
- Thien Thien Lim
- Island Hospital, 308 Macalister Road, 10450 Penang, Malaysia.
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Hor JY, Lim TT, Chia YK, Ching YM, Cheah CF, Tan K, Chow HB, Arip M, Eow GB, Easaw PES, Leite MI. Prevalence of neuromyelitis optica spectrum disorder in the multi-ethnic Penang Island, Malaysia, and a review of worldwide prevalence. Mult Scler Relat Disord 2017; 19:20-24. [PMID: 29100047 DOI: 10.1016/j.msard.2017.10.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/03/2017] [Accepted: 10/20/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Neuromyelitis optica spectrum disorder (NMOSD) occurs worldwide in all ethnicities. Recently, population-based studies have shown that NMOSD is more common among non-White populations. There is scarce data about NMOSD prevalence in South East Asian populations. METHODS (1) A population-based study was undertaken to estimate NMOSD prevalence in the multi-ethnic Penang Island, Malaysia, comprising Chinese, Malays, and Indians. Medical records of NMOSD patients followed up at the Penang General Hospital (the neurology referral centre in Penang Island) were reviewed. The 2015 diagnostic criteria of the International Panel for NMO Diagnosis were used for case ascertainment. (2) A review of population-based prevalence studies of NMOSD worldwide was carried out. PubMed and conference proceedings were searched for such studies. RESULTS Of the 28 NMOSD patients, 14 were residents of Penang Island on prevalence day [13 (93%) Chinese and one (7%) Malay]. All 14 patients were females and aquaporin 4 seropositive. The prevalence of NMOSD in Penang Island was 1.99/100,000 population; according to ethnicities, the prevalence in Chinese was significantly higher than in Malays (3.31/100,000 vs 0.43/100,000, respectively, p = 0.0195). CONCLUSION Based on our and other population-based studies, among Asians, East Asian origin populations (Chinese and Japanese) appear to have higher NMOSD prevalence than other Asian ethnic groups. Worldwide, Blacks seem to have the highest NMOSD prevalence. More studies in different geographical regions and ethnic groups will be useful to further inform about potential factors in NMOSD pathogenesis.
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Affiliation(s)
- Jyh Yung Hor
- Department of Neurology, Penang General Hospital, Penang, Malaysia; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
| | | | - Yuen Kang Chia
- Department of Neurology, Penang General Hospital, Penang, Malaysia
| | - Yee Ming Ching
- Autoimmune Unit, Allergy & Immunology Research Centre, Institute for Medical Research, Kuala Lumpur, Malaysia
| | - Chun Fai Cheah
- Department of Neurology, Penang General Hospital, Penang, Malaysia
| | - Kenny Tan
- Department of Neurology, Penang General Hospital, Penang, Malaysia
| | - Han Bing Chow
- Department of Neurology, Penang General Hospital, Penang, Malaysia
| | - Masita Arip
- Autoimmune Unit, Allergy & Immunology Research Centre, Institute for Medical Research, Kuala Lumpur, Malaysia
| | - Gaik Bee Eow
- Department of Neurology, Penang General Hospital, Penang, Malaysia
| | - P E Samuel Easaw
- Department of Medicine, Penang Medical College, Penang, Malaysia
| | - M Isabel Leite
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
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Abstract
This paper reports the results of combined experimental and numerical studies on the ground effect on a pair of three-dimensional (3D) hovering wings. Parameters investigated include hovering kinematics, wing shapes, and Reynolds numbers (Re). The results are consistent with the observation by another study (Gao and Lu, 2008 Phys. Fluids, 20 087101) which shows that the cycle-averaged aerodynamic forces generated by two-dimensional (2D) wings in close proximity to the ground can be broadly categorized into three regimes with respect to the ground clearance; force enhancement, force reduction, and force recovery. However, the ground effect on a 3D wing is not as significant as that on a 2D flapping wing reported in (Lu et al 2014 Exp. Fluids, 55 1787); this could be attributed to a weaker wake capture effect on 3D wings. Also, unlike a 2D wing, the leading edge vortex (LEV) remains attached on a 3D wing regardless of ground clearance. For all the wing kinematics considered, the three above-mentioned regimes are closely correlated to a non-monotonic trend in the strength of downwash due to the restriction of root and tip vortex formation, and a positional shift of wake vortices. The root vortices in interaction with the ground induce an up-wash in-between the two wings, causing a strong 'fountain effect' (Maeda and Liu, 2013 J. Biomech. Sci. Eng., 8 344) that may increase the body lift of insects. The present study further shows that changes in wing planform have insignificant influence on the overall trend of ground effect except for a parallel shift in force magnitude, which is caused mainly by the difference in aspect ratio and leading edge pivot point. On the two Reynolds numbers investigated, the results for the low Re case of 100 do not deviate significantly from those of a higher Re = 5000 except for the difference in force magnitudes, since low Reynolds number generates lower downwash, weaker LEV, and lower rotational circulation. Additionally, lower Re leads to a weaker fountain effect.
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Affiliation(s)
- H Lu
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Block EA 07-08, Singapore 117575, Singapore
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Lim TT, Kluger BM, Rodriguez RL, Malaty IA, Palacio R, Ojo OO, Patel S, Gujrati Y, Nutter B, Swartz C, Hennessy C, Fernandez HH. Rasagiline for the symptomatic treatment of fatigue in Parkinson's disease. Mov Disord 2016; 30:1825-30. [PMID: 26769459 DOI: 10.1002/mds.26429] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 07/30/2015] [Accepted: 08/04/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Fatigue affects 40% to 50% of all PD patients and is a leading cause of disability, with no clearly established or efficacious established treatments. METHODS In this double-blinded, placebo-controlled, pilot trial, we investigated whether rasagiline improved fatigue among PD patients. Subjects were randomized to 1 mg daily of rasagiline or placebo for 12 weeks. The primary endpoint was a change in the Modified Fatigue Impact Scale from baseline to week 12. RESULTS Thirty PD subjects (16 men), with Modified Fatigue Impact Scale baseline score of 67 ± 15, were randomized (16 to rasagiline vs. 14 to placebo). Significant improvement was noted in the mean Modified Fatigue Impact Scale score of the rasagiline group (12 points) as compared to placebo (8.5 points) from baseline to week 12 (P = 0.003). CONCLUSION In this pilot study, rasagiline at a dose of 1 mg per day improved fatigue. Larger randomized studies are needed to confirm this finding.
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Abstract
Numerical simulations have been conducted to investigate the effect of aspect ratio (AR) on the mean lift generation of a revolving flat rectangular wing. The purpose of the study is to address some discrepancies reported in the literature regarding the influence of AR on mean lift coefficient. Here, we consider a range of AR from 1 to 10 and Rossby number (Ro) from 0.58 to 7.57, and our results show that different degrees of coupling between AR and Ro yield different trends of a mean lift coefficient with respect to increasing AR. The choice of reference velocity for the normalisation of mean lift forces also has a significant effect on the perceived AR effect. By isolating the effect of Ro, we found that higher AR produces higher mean lift coefficient until it plateaus at a sufficiently high AR. This finding is consistent with conventional fixed wing aerodynamics. Additionally, our results show that increasing AR reduces the three-dimensional wing tip effect and is beneficial to mean lift generation while higher Ro increases leading-edge vortex instability, which is detrimental to mean lift generation. Therefore, mean lift generation on revolving wings is dictated by the competition between these two factors, which represent two fundamentally independent phenomena.
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Affiliation(s)
- Y J Lee
- Department of Mechanical Engineering, National University of Singapore, 117575, Singapore
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Abstract
An improved quasi-steady aerodynamic model for flapping wings in hover has been developed. The purpose of this model is to yield rapid predictions of lift generation and efficiency during the design phase of flapping wing micro air vehicles. While most existing models are tailored for a specific flow condition, the present model is applicable over a wider range of Reynolds number and Rossby number. The effects of wing aspect ratio and taper ratio are also considered. The model was validated by comparing against numerical simulations and experimental measurements. Wings with different geometries undergoing distinct kinematics at varying flow conditions were tested during validation. Generally, model predictions of mean force coefficients were within 10% of numerical simulation results, while the deviations in power coefficients could be up to 15%. The deviation is partly due to the model not taking into consideration the initial shedding of the leading-edge vortex and wing-wake interaction which are difficult to account under quasi-steady assumption. The accuracy of this model is comparable to other models in literature, which had to be specifically designed or tuned to a narrow range of operation. In contrast, the present model has the advantage of being applicable over a wider range of flow conditions without prior tuning or calibration, which makes it a useful tool for preliminary performance evaluations.
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Affiliation(s)
- Y J Lee
- Department of Mechanical Engineering, National University of Singapore, 117575, Singapore
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Dang YL, Hor JY, Chia YK, Lim TT, Eow GB. Suprasellar lymphoma masquerading as tuberculosis of the central nervous system. Acta Neurol Belg 2014; 114:239-41. [PMID: 23757110 DOI: 10.1007/s13760-013-0217-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/06/2013] [Indexed: 10/26/2022]
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Rezaeinejad S, Vergara GGRV, Woo CH, Lim TT, Sobsey MD, Gin KYH. Surveillance of enteric viruses and coliphages in a tropical urban catchment. Water Res 2014; 58:122-31. [PMID: 24747143 DOI: 10.1016/j.watres.2014.03.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 05/13/2023]
Abstract
An assessment of the occurrence and concentration of enteric viruses and coliphages was carried out in highly urbanized catchment waters in the tropical city-state of Singapore. Target enteric viruses in this study were noroviruses, adenoviruses, astroviruses and rotaviruses. In total, 65 water samples were collected from canals and the reservoir of the Marina catchment on a monthly basis over a period of a year. Quantitative PCR (qPCR) and single agar layer plaque assay (SAL) were used to enumerate target enteric viruses and coliphages in water samples, respectively. The most prevalent pathogen were noroviruses, detected in 37 samples (57%), particularly norovirus genogroup II (48%), with a mean concentration of 3.7 × 10(2) gene copies per liter. Rotavirus was the second most prevalent virus (40%) with a mean concentration of 2.5 × 10(2) GC/L. The mean concentrations of somatic and male-specific coliphages were 2.2 × 10(2) and 1.1 × 10(2) PFU/100 ml, respectively. The occurrence and concentration of each target virus and the ratio of somatic to male-specific coliphages varied at different sampling sites in the catchment. For sampling sites with higher frequency of occurrence and concentration of viruses, the ratio of somatic to male-specific coliphages was generally much lower than other sampling sites with lower incidences of enteric viruses. Overall, higher statistical correlation was observed between target enteric viruses than between enteric viruses and coliphages. However, male-specific coliphages were positively correlated with norovirus concentrations. A multi-level integrated surveillance system, which comprises the monitoring of bacterial indicators, coliphages and selected enteric viruses, could help to meet recreational and surface water quality criteria in a complex urbanized catchment.
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Affiliation(s)
- S Rezaeinejad
- Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, Blk E1A-07-03, 1 Engineering Drive 2, Singapore 117576, Singapore
| | - G G R V Vergara
- Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, Blk E1A-07-03, 1 Engineering Drive 2, Singapore 117576, Singapore
| | - C H Woo
- Technology and Water Quality Office, Public Utilities Board, Singapore
| | - T T Lim
- Technology and Water Quality Office, Public Utilities Board, Singapore
| | - M D Sobsey
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - K Y H Gin
- Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, Blk E1A-07-03, 1 Engineering Drive 2, Singapore 117576, Singapore.
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Lim TT, Fernandez HH, Cooper S, Wilson KMK, Machado AG. Successful deep brain stimulation surgery with intraoperative magnetic resonance imaging on a difficult neuroacanthocytosis case: case report. Neurosurgery 2014; 73:E184-7; discussion E188. [PMID: 23615095 DOI: 10.1227/01.neu.0000429852.45073.73] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND IMPORTANCE Chorea acanthocytosis is a progressive hereditary neurodegenerative disorder characterized by hyperkinetic movements, seizures, and acanthocytosis in the absence of any lipid abnormality. Medical treatment is typically limited and disappointing. CLINICAL PRESENTATION We report on a 32-year-old patient with chorea acanthocytosis with a failed attempt at awake deep brain stimulation (DBS) surgery due to intraoperative seizures and postoperative intracranial hematoma. He then underwent a second DBS operation, but under general anesthesia and with intraoperative magnetic resonance imaging guidance. Marked improvement in his dystonia, chorea, and overall quality of life was noted 2 and 8 months postoperatively. CONCLUSION DBS surgery of the bilateral globus pallidus pars interna may be useful in controlling the hyperkinetic movements in neuroacanthocytosis. Because of the high propensity for seizures in this disorder, DBS performed under general anesthesia, with intraoperative magnetic resonance imaging guidance, may allow successful implantation while maintaining accurate target localization.
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Affiliation(s)
- Thien Thien Lim
- Center of Neurological Restoration, Neurological Institute, Cleveland Clinic, Ohio, USA.
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Gopalai AA, Lim SY, Abdul Aziz Z, Lim SK, Tan LP, Chong YB, Tan CT, Puvanarajah S, Viswanathan S, Kuppusamy R, Tan AH, Lim TT, Eow GB, Norlinah MI, Li HH, Zhao Y, Ahmad-Annuar A. Lack of Association between the LRRK2 A419V Variant and Asian Parkinson’s Disease. Ann Acad Med Singap 2013. [DOI: 10.47102/annals-acadmedsg.v42n5p237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Introduction: The G2385R and R1628P LRRK2 gene variants have been associated with an increased risk of Parkinson’s disease (PD) in the Asian population. Recently, a new LRRK2 gene variant, A419V, was reported to be a third risk variant for PD in Asian patients. Our objective was to investigate this finding in our cohort of Asian subjects. Materials and Methods: Eight hundred and twenty-eight subjects (404 PD patients, and 424 age and gender-matched control subjects without neurological disorders) were recruited. Genotyping was done by Taqman® allelic discrimination assay on an Applied Biosystems 7500 Fast Real-Time PCR machine. Results: The heterozygous A419V genotype was found in only 1 patient with PD, compared to 3 in the control group (0.4% vs 1.3%), giving an odds ratio of 0.35 (95% confidence interval (CI), 0.01 to 3.79; P = 0.624). Conclusion: A419V is not an important LRRK2 risk variant in our Asian cohort of patients with PD. Our data are further supported by a literature review which showed that 4 out of 6 published studies reported a negative association of this variant in PD.
Key words: Asian, A419V, Genetics, LRRK2, Parkinson’s disease
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Affiliation(s)
| | | | | | - Soo Kun Lim
- Faculty of Medicine, University of Malaya, Malaysia
| | - Li Ping Tan
- Faculty of Medicine, University of Malaya, Malaysia
| | | | | | | | | | | | - Ai Huey Tan
- Faculty of Medicine, University of Malaya, Malaysia
| | | | | | | | - Hui Hua Li
- Singapore General Hospital, National Neuroscience Institute, Singapore
| | - Yi Zhao
- Singapore General Hospital, National Neuroscience Institute, Singapore
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Gopalai AA, Lim SY, Aziz ZA, Lim SK, Tan LP, Chong YB, Tan CT, Puvanarajah S, Viswanathan S, Kuppusamy R, Tan AH, Lim TT, Eow GB, Norlinah MI, Li HH, Zhao Y, Ahmad-Annuar A. Lack of association between the LRRK2 A419V variant and Asian Parkinson's disease. Ann Acad Med Singap 2013; 42:237-240. [PMID: 23771111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
INTRODUCTION The G2385R and R1628P LRRK2 gene variants have been associated with an increased risk of Parkinson's disease (PD) in the Asian population. Recently, a new LRRK2 gene variant, A419V, was reported to be a third risk variant for PD in Asian patients. Our objective was to investigate this finding in our cohort of Asian subjects. MATERIALS AND METHODS Eight hundred and twenty-eight subjects (404 PD patients, and 424 age and gender-matched control subjects without neurological disorders) were recruited. Genotyping was done by Taqman® allelic discrimination assay on an Applied Biosystems 7500 Fast Real-Time PCR machine. RESULTS The heterozygous A419V genotype was found in only 1 patient with PD, compared to 3 in the control group (0.4% vs 1.3%), giving an odds ratio of 0.35 (95% confidence interval (CI), 0.01 to 3.79; P = 0.624). CONCLUSION A419V is not an important LRRK2 risk variant in our Asian cohort of patients with PD. Our data are further supported by a literature review which showed that 4 out of 6 published studies reported a negative association of this variant in PD.
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Affiliation(s)
- Aroma Agape Gopalai
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Malaysia
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Lim TT, Ahmed A, Itin I, Gostkowski M, Rudolph J, Cooper S, Fernandez HH. Is 6 months of neuroleptic withdrawal sufficient to distinguish drug-induced parkinsonism from Parkinson's disease? Int J Neurosci 2013; 123:170-4. [PMID: 23078283 DOI: 10.3109/00207454.2012.732976] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Drug-induced parkinsonism (DIP) is the second commonest cause of akinetic-rigid syndrome in the western world. Differentiating DIP from Parkinson's disease (PD) may be a challenge to clinicians. One of the factors distinguishing DIP from PD is that discontinuation of the neuroleptic agent in DIP should relieve the symptoms of parkinsonism. The majority of the literature uses the 6-month timeframe between the neuroleptic withdrawal and resolution of the symptoms of parkinsonism. METHODS We report two cases of DIP wherein the symptoms of parkinsonism persisted more than 6-months from withdrawal of the dopamine receptor blocking agent (DRBA) and the results of their ioflupane iodine-123 (DaT) single-photon emission computed tomography (SPECT) scan. DaT scan is a newly approved radiopharmaceutical in the United States indicated for striatal dopamine transporter visualization to assist in the evaluation of adult patients with suspected parkinsonian syndromes. RESULTS The first case is a patient who developed parkinsonism from risperidone, while the second case developed parkinsonism from metoclopramide. In both cases, parkinsonism persisted 6 months after discontinuation of the DRBA, therefore DaT scan was obtained, showing normal striatal dopamine transporter uptake. Nine months after the discontinuation of the DRBA, parkinsonism was significantly improved in both patients but not completely resolved. CONCLUSION Our two cases illustrate the possibility of persistent parkinsonism beyond 6-9 months from the time of neuroleptic withdrawal without evidence of presynaptic dopaminergic neuronal loss that would be suggestive of conversion to PD. We recommend that the official recommendation of the minimum time of neuroleptic withdrawal be modified to at least 1 year before entertaining the diagnosis of PD conversion in patients with exposure to DRBAs.
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Affiliation(s)
- T T Lim
- Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio, USA
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Lim TT, Itin I, Fernandez HH. Pseudopsychogenic Tremors and Parkinsonism: Two Presentations of Multiple Sclerosis That Almost Fooled Us. Mov Disord 2012. [DOI: 10.1891/9781617050589.0042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Lim TT, Itin I, Hantus S, Fernandez HH. Untwisting a Double Twist: Severe Tremors in a Factory Worker With a Melanoma History. Mov Disord 2012. [DOI: 10.1891/9781617050589.0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Abstract
1. Ammonia (NH(3)) is an important gaseous pollutant generated from manure in commercial poultry farms and has been an environmental, ecological, and health concern. Poultry manure also releases carbon dioxide (CO(2)), which is a greenhouse gas and is often used as a tracer gas to calculate building ventilation. 2. A 38-d laboratory study was conducted to evaluate the characteristics of NH(3) and CO(2) releases from layer hen manure using 4 manure reactors (122 cm tall, 38 cm internal diameter), which were initially filled with 66 cm deep manure followed by weekly additions of 5 cm to simulate manure accumulation in commercial layer houses. 3. The average daily mean (ADM) NH(3) and CO(2) release fluxes for the 4 reactors during the entire study were 1615 +/- 211 microg/s.m(2) (ADM +/- 95% confidence interval) and 100 +/- 03 mg/s.m(2), respectively. The daily mean NH(3) and CO(2) releases in individual reactors varied from 352 to 6791 microg/s.m(2) and from 66 to 205 mg/s.m(2), respectively. 4. The ADM NH(3) release flux was within the range of those obtained in 4 high-rise layer houses by Liang et al. (2005, Transactions of the ASAE, 48). However, the CO(2) release flux in this study was about 10 to 13 times as high as the data reported by Liang et al. (2005). Fresh manure had greater NH(3) release potential than the manure in the reactors under continuous ventilation. Manure with higher contents of moisture, total nitrogen, and ammonium in the 4th weekly addition induced 11 times higher NH(3) and 75% higher CO(2) releases immediately after manure addition compared with pre-addition releases.
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Affiliation(s)
- J-Q Ni
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN, USA.
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Goh KH, Lim TT, Dong ZL. Removal of arsenate from aqueous solution by nanocrystalline Mg/Al layered double hydroxide: sorption characteristics, prospects, and challenges. Water Sci Technol 2010; 61:1411-1417. [PMID: 20351419 DOI: 10.2166/wst.2010.855] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Removal of arsenate (As(V)) from aqueous solution using both nanocrystalline and coprecipitated Mg/Al layered double hydroxides (LDHs) was examined under different sorption/desorption conditions. The surface area, pore volume, and pore size of the nanocrystalline LDH were significantly higher than those of the coprecipitated LDH, thus resulting in a higher As(V) sorption maximum than the coprecipitated LDH. The calculated activation energy (E(a)) value was 24.7 kJ/mol, suggesting the occurrence of anion exchange process for As(V) removal by the nanocrystalline LDH. The predominance of anion exchange process was further supported by the investigation of ionic strength effect, and XRD and FTIR analyses. The effect of aqueous matrix on As(V) sorption by the nanocrystalline LDH was found to increase in the order of nitrate < silica < sulfate < carbonate < phosphate. Regeneration study showed that a secondary sorption mechanism might occur concurrently for the As(V) sorption by nanocrystalline LDH besides the predominant anion exchange process. Prospects and challenges for practical application of the nanocrystalline LDH were also discussed in the latter part of this study.
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Affiliation(s)
- K H Goh
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639789, Singapore.
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Lim TT, Goh KH, Goei R, Dong ZL. Mechanistic and thermodynamic studies of oxyanion sorption by various synthetic Mg/Al layered double hydroxides. Water Sci Technol 2009; 59:1011-1017. [PMID: 19273901 DOI: 10.2166/wst.2009.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this study, Mg/Al layered double hydroxides (LDHs) were investigated for their potential in scavenging several harmful oxyanions from aqueous solution. LDHs could effectively remove oxyanions and the selectivity of LDHs was governed by both the valencies and the ionic radii of the oxyanions. LDHs prepared by the fast coprecipitation with hydrothermal treatment (FCHT) method and sol-gel with solvothermal treatment method (SGST) had higher oxyanion (i.e. arsenate) removal efficiency than those prepared by the conventional routes, owing to their lower carbonate content, higher surface area, larger pore volume, larger pore size, and nanocrystalline characteristic. The sorption of arsenate by FCHT-LDH was found primarily due to anion exchange mechanism and might involve a secondary sorption mechanism. The negative DeltaG degrees for arsenate sorption confirmed the spontaneity of the removal process. The positive values of DeltaH degrees and DeltaS degrees provided further evidence of the anion exchange process in the removal mechanism.
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Affiliation(s)
- T T Lim
- School of Civil and Environmental Engineering, Nanyang Technological University, 50, Nanyang Avenue, Singapore, 639789, Singapore.
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Chua LHC, Leong MCM, Lo EYM, Reinhard M, Robertson AP, Lim TT, Shuy EB, Tan SK. Controlled field studies on soil aquifer treatment in a constructed coastal sandfill. Water Sci Technol 2009; 60:1283-1293. [PMID: 19717916 DOI: 10.2166/wst.2009.408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A controlled artificial recharge experiment was conducted to investigate the effect of soil aquifer treatment during percolation of secondary and tertiary (ultrafiltered) treated wastewater through the shallow vadoze zone of a newly constructed coastal sandfill. The sandfill is a reclaimed land constructed from marine sand dredged from the seabed. To obtain 1-D flow, a stainless steel column was driven to a depth of 2.5 m, penetrating the phreatic surface. Wastewater was percolated through the column under fully-saturated and unsaturated conditions. Infiltration rates, dissolved organic carbon (DOC) and ultra-violet absorption (UVA) were monitored. The wastewaters were recharged at similar infiltration rates of approximately 5.5 m/day and 3.5 m/day under fully-saturated and unsaturated conditions, respectively. In both cases, clogging occurred 40 days after the start of recharge, under saturated conditions. For secondary treated wastewater, DOC concentration (mg/l) reduced by 28% and 13% under unsaturated and saturated conditions, respectively. The corresponding UVA reduction was 19.4% and 14.1%. Similar reductions in DOC were observed for the tertiary treated wastewater; however, the reduction in UVA was higher; 28% and 22% under unsaturated and saturated conditions, respectively. On an mass removal (mg/m(2) DOC) basis, DOC reduction appeared to be more significant under unsaturated conditions. This is attributed to the presence of interstitial oxygen.
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Affiliation(s)
- Lloyd H C Chua
- Division of Environmental and Water Resources Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
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Abstract
We have developed a bioreactor vessel design which has the advantages of simplicity and ease of assembly and disassembly, and with the appropriately determined flow rate, even allows for a scaffold to be suspended freely regardless of its weight. This article reports our experimental and numerical investigations to evaluate the performance of a newly developed non-perfusion conical bioreactor by visualizing the flow through scaffolds with 45 degrees and 90 degrees fiber lay down patterns. The experiments were conducted at the Reynolds numbers (Re) 121, 170, and 218 based on the local velocity and width of scaffolds. The flow fields were captured using short-time exposures of 60 microm particles suspended in the bioreactor and illuminated using a thin laser sheet. The effects of scaffold fiber lay down pattern and Reynolds number were obtained and correspondingly compared to results obtained from a computational fluid dynamics (CFD) software package. The objectives of this article are twofold: to investigate the hypothesis that there may be an insufficient exchange of medium within the interior of the scaffold when using our non-perfusion bioreactor, and second, to compare the flows within and around scaffolds of 45 degrees and 90 degrees fiber lay down patterns. Scaffold porosity was also found to influence flow patterns. It was therefore shown that fluidic transport could be achieved within scaffolds with our bioreactor design, being a non-perfusion vessel. Fluid velocities were generally same of the same or one order lower in magnitude as compared to the inlet flow velocity. Additionally, the 90 degrees fiber lay down pattern scaffold was found to allow for slightly higher fluid velocities within, as compared to the 45 degrees fiber lay down pattern scaffold. This was due to the architecture and pore arrangement of the 90 degrees fiber lay down pattern scaffold, which allows for fluid to flow directly through (channel-like flow).
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Affiliation(s)
- Harmeet Singh
- Department of Orthopaedic Surgery, Division of Bioengineering, National University of Singapore, Engineering Drive 1, Yong Loo Lin School of Medicine, Singapore 119260, Singapore
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Abstract
A drift and pumpback experiment was conducted in a brackish water sandfill. The sandfill was reclaimed from the sea in the eastern part of Singapore and contains sands with low organic and clay/silt contents. The high salinity in the ground water precludes the use of chloride and bromide as tracers in such an environment, and a field experiment was conducted to assess the viability of using fluorescein as a tracer in brackish water aquifers. Nitrate was used as a second tracer to serve as a check. Initial laboratory studies showed that fluorescence was unaffected over the range of electrical conductivity and pH of the ground water. Results from the field experiment show that fluorescein appears to behave conservatively.
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Affiliation(s)
- Lloyd H C Chua
- Division of Environmental and Water Resources Engineering, Nanyang Technologial University, Singapore.
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Lim YP, Lim TT, Chan YL, Song ACM, Yeo BH, Vojtesek B, Coomber D, Rajagopal G, Lane D. The p53 knowledgebase: an integrated information resource for p53 research. Oncogene 2006; 26:1517-21. [PMID: 16953220 DOI: 10.1038/sj.onc.1209952] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The p53 tumor suppressor protein plays a central role in maintaining genomic integrity by occupying a nodal point in the DNA damage control pathway. Here it integrates a wide variety of signals, responding in one of several ways, that is, cell cycle arrest, senescence or programmed cell death (apoptosis). Mutations in the tumor suppressor gene tp53, which affects the key transcriptional regulatory processes in cell growth and death, occur frequently in cancer and helps explain why p53 has been called the guardian of the genome. There is a vast body of published knowledge on all aspects of p53's role in cancer. To facilitate research, it would be helpful if this information could be collected, curated and updated in a format that is easily accessible to the user community. To this end, we initiated the p53 knowledgebase project (http://p53.bii.a-star.edu.sg). The p53 knowledgebase is a user-friendly web portal incorporating visualization and analysis tools that integrates information from the published literature with other manually curated information to facilitate knowledge discovery. This includes curated information on sequence, structural, mutation, polymorphisms, protein-protein interactions, transcription factors, transcriptional targets, antibodies and post-translational modifications that involve p53. The goal is to collect and maintain all relevant data on p53 and present it in an easily accessible format that will be useful to researchers in the field.
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Affiliation(s)
- Y P Lim
- Bioinformatics Institute, Matrix, Singapore, Singapore
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Lim TT, Chu J, Goi MH. Effects of cement on redistribution of trace metals and dissolution of organics in sewage sludge and its inorganic waste-amended products. Waste Manag 2006; 26:1294-304. [PMID: 16364627 DOI: 10.1016/j.wasman.2005.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Revised: 08/17/2005] [Accepted: 11/07/2005] [Indexed: 05/05/2023]
Abstract
The suitability of using cement-stabilized sludge products as artificial soils in earth works was evaluated. The sludge products investigated were cemented sludge, cement-treated clay-amended sludge (SS+MC), and cement-treated copper slag-amended sludge (SS+CS). The leachability of lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) were assessed using the sequential extraction technique, toxicity characteristic leaching procedure (TCLP), NEN 7341 availability test, and column leaching test. The results indicated that Zn leachability was reduced in all the cement-stabilized sludge products. In contrast, Cu was transferred from the organic fraction to the readily leachable phases in the cement-stabilized sludge products and therefore exhibited increased leachability. The increased Cu leachability could be attributed to dissolution of humic substances in the sludge as a result of elevated pH. Good correlation between dissolved organic carbon (DOC) and heavy metal leaching from the cement-stabilized sludge products was observed in the column leaching experiment. Even with a cement percentage as small as 12.5%, calcium silicate hydrate (C-S-H) was formed in the SS+MC and SS+CS products. Inclusion of the marine clay in the SS+MC products could reduce the leaching potentials of Zn, and this was the great advantage of the marine clay over the copper slag for sludge amendment.
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Affiliation(s)
- T T Lim
- School of Civil and Environmental Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore.
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O'Brien FG, Lim TT, Chong FN, Coombs GW, Enright MC, Robinson DA, Monk A, Saïd-Salim B, Kreiswirth BN, Grubb WB. Diversity among community isolates of methicillin-resistant Staphylococcus aureus in Australia. J Clin Microbiol 2004; 42:3185-90. [PMID: 15243080 PMCID: PMC446257 DOI: 10.1128/jcm.42.7.3185-3190.2004] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Community methicillin-resistant Staphylococcus aureus (CMRSA) strains are being isolated with increasing frequency around the world. In Western Australia CMRSA are endemic in geographically remote communities and have been found to belong to five different contour-clamped homogeneous electric field (CHEF) electrophoretic patterns. Representatives of each of these CHEF patterns have been compared to CMRSA representative of CHEF patterns from other Australian states and New Zealand. With one exception, all of the isolates were nonmultiresistant and were not resistant to many antimicrobial agents other than the beta-lactams. With one exception, which is not believed to be a CMRSA, all of the isolates harbored a beta-lactamase plasmid. Erythromycin resistance was associated with a 2-kb plasmid. One of the beta-lactamase plasmids was found to be able to acquire additional resistance determinants to become a multiple resistance plasmid. There were 10 multilocus sequence types belonging to eight distantly related clonal complexes of S. aureus. One new sequence type was found. Although most of the CMRSA harbored the type IVa SCCmec, a type IV structural variant was found and two new SCCmec types were identified. Protein A gene (spa) typing revealed two new spa types and, with two exceptions, corresponded to multilocus sequence typing. In contrast to other reports on CMRSA, most of the CMRSA strains studied here did not contain the Panton-Valentine leukocidin genes. The results also demonstrate that nonmultiresistant hospital strains such as UK EMRSA-15 may be able to circulate in the community and could be mistaken for CMRSA based on their resistance profiles.
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Affiliation(s)
- F G O'Brien
- Gram-Positive Bacteria Typing and Research Unit, Curtin University of Technology, School of Biomedical Sciences, GPO Box U1987, Perth, Western Australia 6845, Australia
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Kwok BW, Lim TT. Cortical blindness following coronary angiography. Singapore Med J 2000; 41:604-5. [PMID: 11296788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A 53-year-old man developed transient cortical blindness after coronary angiography, which appears to be an adverse reaction to contrast agent. A possible mechanism of this complication is contrast penetration of the blood-brain barrier with direct neurotoxicity to the occipital cortex.
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Affiliation(s)
- B W Kwok
- Cardiac Department, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074
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Tan HC, Lim YT, Lim TT, Cheng A, Chia BL. The use of abciximab in coronary angioplasty--an Asian centre's experience. Singapore Med J 2000; 41:69-73. [PMID: 11063206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND Abciximab, a monoclonal antibody to platelet glycoprotein IIb/IIIa receptor, has been shown to be effective in reducing ischemic complications after coronary angioplasty in recent trials. However, little is known about its efficacy and safety when used in Asian patients. METHODOLOGY Based on our abciximab registry, we performed a retrospective analysis of 115 Asian patients who received the antiplatelet agent while undergoing percutaneous coronary intervention in our centre. They constituted 18.4% of the total number of patients undergoing percutaneous revascularisation during the corresponding period. The majority of the patients were males (84%). The mean age of the cohort was 54 and the mean weight was 70 kg. The ethnic composition of the study population was: Chinese 54%, Indians 21%, Malays 19% and Others 6%. All patients received aspirin 100 mg and weight-adjusted heparin before the procedure. Abciximab may be administered on a preplanned basis prior to the procedure or be given as a 'bailout' strategy. RESULTS There was a high clinical success rate of 95.8% and low incidence of ischemic complications when abciximab was given during coronary angioplasty. There were 0% Q myocardial infarction, 3.3% non-Q myocardial infarction and 0.8% death in our series. Bleeding complications were uncommon at 7.6%, predominantly involving the groin and gingiva. Thrombocytopenia occurred in 5.8% of patients. Abciximab was noted to increase the procedural activated clotting time (ACT) by 38 seconds when given concomitantly with heparin. The mean maximal procedural ACT achieved was 323 +/- 51 seconds. CONCLUSIONS Abciximab may be used safely and efficaciously in Asian patients undergoing coronary angioplasty. The drug confers protection against ischemic complications during the procedure whether it is administered electively or as a 'bailout'. There is however, a need to redefine the heparin regime for our patients, given the high ACT obtained when abciximab is administered.
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Affiliation(s)
- H C Tan
- Cardiac Department, National University Hospital, Singapore
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Sim EK, Grignani RT, Cheng A, Lim TT, Lim YT, Saw HS. Hybrid cardiac revascularisation surgery. Singapore Med J 2000; 41:36-8. [PMID: 10783680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Currently, 3 methods of myocardial revascularisation are available for the treatment of coronary artery disease: i) coronary artery bypass grafting (CABG); ii) percutaneous transluminal coronary angiography (PTCA), and iii) transmyocardial laser revascularisation (TMR). Until recently, these procedures were performed exclusive to one another. We report 2 cases of minimally invasive direct coronary artery bypass grafting with subsequent PTCA, and 1 case of staged PTCA followed by TMR performed at our institution. We discuss the role of hybrid procedures in the current era of treatment of ischaemic heart disease.
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Affiliation(s)
- E K Sim
- Cardiac Department, National University Hospital, Singapore
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Chia KH, Ong HS, Teoh MK, Lim TT, Tan SG. Chronic haemodialysis with PTFE arterio-venous grafts. Singapore Med J 1999; 40:685-90. [PMID: 10709405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND/AIM OF STUDY End-stage renal failure (ESRF) patients requiring long-term haemodialysis need a durable vascular access. The arterio-venous fistula (AVF) with its long patency rate and low complication profile is usually the first choice procedure for vascular access creation. However when superficial veins are not suitable for AVF creation or have all been exhausted as a result of repeated AVF procedures, arterio-venous grafts (AVG) using polytetraflouroethylene (PTFE) to bridge arteries and veins is an alternative for provision of continued vascular access for haemodialysis. This study is a review of our experience in using PTFE AVGs for vascular access in patients requiring chronic haemodialysis. METHODS AND MATERIALS A retrospective review was done on 92 grafts in 77 patients placed by 3 vascular access surgeons at the Singapore General Hospital from January 1989 to December 1994. RESULTS There were 58 female and 19 male patients with a median age of 43 years (range 15-76 years). Twelve patients (16%) were diabetic and 6 patients (8%) had systemic lupus erythematosis requiring long-term steroids. Seventy-three percent of patients had up to 2 previous AVF creations before placement of AVG over the forearm (64%), upper arm (23%) or thigh (6.5%). Complications include graft infection (19), pseudoaneurysm formation (10), graft thrombosis (24), steal syndrome (1), venous congestion (1) and venous end stenosis (1). Diabetic status and long-term steroid therapy did not significantly increase the incidence of graft infection. The patency rates at 24 months and 36 months were 77% and 58% respectively. However serviceability rates were 61% at 2 years and 38% at 3 years mainly due to infective complications. CONCLUSION PTFE AVGs offer reasonable patency and serviceability rates as a vascular access modality but in view of their complication profile, the native vein arteriovenous fistula should continue to be the first choice procedure for vascular access in patients requiring chronic haemodialysis.
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Affiliation(s)
- K H Chia
- Department of General Surgery, Singapore General Hospital, Singapore
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Schwarzacher SP, Lim TT, Wang B, Kernoff RS, Niebauer J, Cooke JP, Yeung AC. Local intramural delivery of L-arginine enhances nitric oxide generation and inhibits lesion formation after balloon angioplasty. Circulation 1997; 95:1863-9. [PMID: 9107174 DOI: 10.1161/01.cir.95.7.1863] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Long-term oral administration of L-arginine has been shown to enhance production of nitric oxide (NO) and to reduce lesion formation. The goal of this study was to determine whether local intramural administration of L-arginine could enhance NO generation and reduce intimal thickening. METHODS AND RESULTS New Zealand White rabbits (n = 27) received a 1% cholesterol diet. For the short-term study, after 1 week of diet, both iliac arteries were balloon injured. Four weeks later, vasoreactivity was assessed angiographically during infusion of acetylcholine (Ach) before and after delivery of L-arginine or saline into the right or left iliac artery (800 mg/5 mL; 0.2 mL/min, 15 minutes) by use of a local drug-delivery balloon. Vessels were then harvested for measurements of NO. For the long-term study, after balloon injury, drugs were delivered as above into the iliac arteries. Two and 4 weeks after L-arginine delivery, vasoreactivity was determined. Subsequently, the iliac arteries were harvested for histomorphometric analysis and measurements of NO. In the short-term study, local delivery of L-arginine restored endothelium-dependent vasodilatation (Ach 10(-5) mol/L; L-arginine +35 +/- 10%; saline -14 +/- 5%; P < .001) and enhanced local production of nitrogen oxides (L-arginine 152 +/- 28; saline 78 +/- 12 nmol/L per milligram of tissue per hour; P < .04). In the long-term study, local administration of L-arginine enhanced vascular NO production as long as 1 week after the injury (L-arginine 394.4 +/- 141.6; saline 86.3 +/- 34.3 nmol/L per milligram of tissue per hour; P < .01) and reduced intimal thickening 4 weeks later (intima/ media ratio: L-arginine 0.56 +/- 0.1; saline 1.40 +/- 0.2; P < .001), largely due to suppression of macrophage accumulation. CONCLUSIONS A single intramural administration of L-arginine enhances vascular NO generation and inhibits lesion formation. Local augmentation of NO production at the site of balloon angioplasty may be a novel strategy to prevent restenosis.
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Affiliation(s)
- S P Schwarzacher
- Division of Cardiovascular Medicine, Stanford University School of Medicine, CA 94305, USA
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Lim TT, Liang DH, Botas J, Schroeder JS, Oesterle SN, Yeung AC. Role of compensatory enlargement and shrinkage in transplant coronary artery disease. Serial intravascular ultrasound study. Circulation 1997; 95:855-9. [PMID: 9054742 DOI: 10.1161/01.cir.95.4.855] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Compensatory enlargement of the vessel wall has been described in the early stages of native atherosclerosis. Whether compensatory enlargement plays a role in transplant coronary artery disease is not known. The objective of this study was to determine, by use of serial intravascular ultrasound (IVUS), whether compensatory dilation occurs in transplant coronary artery disease over time. METHODS AND RESULTS Seventy-five heart transplant recipients with 151 matched coronary segments were selected for the presence of intimal disease progression as detected by serial IVUS examinations 1 to 3 years apart. Intimal disease progression was defined as a > 10% increase in intimal area (IA). IVUS catheter location in follow-up studies was verified angiographically in relation to branch vessels. Luminal area (LA) and total vessel area (TA) were measured at each site. Intimal area (IA = TA-LA) was calculated. Changes in IA (delta IA) and TA (delta TA) between baseline and follow-up IVUS were compared: delta IA, 2.9 +/- 0.2 mm2: delta TA, 2.7 +/- 0.4 mm2. A remodeling index (RI) was defined as RI = delta TA/delta IA. Three subgroups could be distinguished: over compensation (RI > I), partial compensation (RI 0 to 1), and no compensation or shrinkage (RI < or = 0). Seventy-four segments (49%) showed overcompensation, 44 (29%) showed partial compensation, and 33 (22%) showed no compensation or shrinkage. CONCLUSIONS In this study, serial IVUS shows that early after cardiac transplantation, a large proportion of the coronary segments with progression of intimal thickening have compensatory dilation of the vessel wall. However, a substantial number of coronary segments (22%) show no compensatory dilation or shrinkage. The progressive luminal narrowing in transplant patients may be due in part to vessel shrinkage or the lack of compensatory dilation over time.
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Affiliation(s)
- T T Lim
- Division of Cardiovascular Medicine, Stanford University Medical Center, CA 94305, USA
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Lim TT, Botas J, Ross H, Liang DH, Theodore J, Hunt SA, Oesterle SN, Yeung AC. Are heart-lung transplant recipients protected from developing transplant coronary artery disease? A case-matched intracoronary ultrasound study. Circulation 1996; 94:1573-7. [PMID: 8840846 DOI: 10.1161/01.cir.94.7.1573] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Accelerated coronary artery disease is a major cause of mortality in heart transplant recipients; however, it does not appear to play a major role in the clinical outcome of heart-lung transplant recipients. The purpose of this study was to determine whether the incidence and severity of transplant coronary artery disease as detected by intracoronary ultrasound in heart-lung transplant recipients are less than those encountered in heart transplant recipients. METHODS AND RESULTS We studied the left anterior descending coronary artery with the use of intracoronary ultrasound imaging in 22 heart-lung transplant recipients at the time of their routine annual coronary angiogram. Twenty-two heart transplant recipients were case matched for number of years after transplant at ultrasound study, recipient age, donor age, and diagnosis of nonischemic cardiomyopathy. Mean intimal area, intimal index, Stanford class, and incidence of at least moderate disease (Stanford class > or = 3) were measured and calculated in each group and then compared between the two groups. Mean intimal area (1.6 +/- 2.5 versus 3.8 +/- 2.8 mm2), mean intimal index (0.07 +/- 0.10 versus 0.22 +/- 0.14), mean Stanford class (1.7 +/- 1.0 versus 2.7 +/- 1.2), and incidence of Stanford class > or = 3 (14% versus 45%) were significantly lower in the heart-lung transplant recipient group. CONCLUSIONS The incidence and severity of transplant coronary artery disease are much less in patients receiving heart-lung transplants than in those receiving heart transplants alone.
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Affiliation(s)
- T T Lim
- Division of Cardiovascular Medicine, Stanford University School of Medicine, CA 94305, USA
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Teo WS, Tan A, Lim TT, Ng A. Radiofrequency catheter ablation of accessory pathways: the initial experience in Singapore. Singapore Med J 1994; 35:36-40. [PMID: 8009275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Radiofrequency catheter ablation is a recently introduced non-surgical technique for curing patients with arrhythmias as a result of conduction over an accessory pathway in patients with the Wolff-Parkinson-White (WPW) syndrome. We present our initial experience with this technique. There were 90 patients (61 males, 29 females) with a mean age of 37 +/- 14.4 years (range: 13-73 years). All except one were symptomatic with a mean duration of symptoms of 10 +/- 9.4 years (range: 0.1-40 years). The indications for catheter ablation were failure of drug therapy in 71, patient's preference in 10, increased risk of sudden death in 6 and almost incessant tachycardia in 3. The radiofrequency ablation was performed using a deflectable 7 French 4 mm tip electrode catheter positioned at the mitral or tricuspid annulus. The site of the accessory pathway was localised by electrophysiological study and radiofrequency energy applied via the tip of the catheter. There were 100 accessory pathways as 10 (10%) patients had multiple accessory pathways. There were 69 (69%) left free wall, 11 (11%) posteroseptal, 13 (13%) right free wall, 6 (6%) right anteroseptal accessory pathways and one (1%) midseptal accessory pathways. Ninety-six percent (96%) of the accessory pathways were successfully ablated on the first ablation. Two of the 4 initially unsuccessful ablations were successfully reablated, giving an overall success rate of 98%. There were no major complications. In conclusion, radiofrequency catheter ablation of accessory pathways is highly successful and safe and provides a definitive cure for patients with the WPW syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W S Teo
- Department of Cardiology, Singapore General Hospital
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Lim TT, Teo WS. Tall precordial T waves: normal variant or acute myocardial infarction? Singapore Med J 1992; 33:195, 206. [PMID: 1621129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- T T Lim
- Department of Cardiology, Singapore General Hospital
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Lim TT, Kuijper EJ, Jansen PL, Speelman P, Lubbers MJ, Dankert J. [The relationship between predisposing factors in liver abscesses and the causative bacteria]. Ned Tijdschr Geneeskd 1991; 135:1437-41. [PMID: 1922453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In order to assess the correlation between bacteria isolated from liver abscesses and factors predisposing to liver abscesses, a retrospective study of clinical and bacteriological data on 21 patients with 27 episodes of pyogenic abscesses was carried out at the University Medical Centre, Amsterdam. Out of 27 episodes, 15 (55%) were associated with biliary or pancreatic disease; in seven of these 15 episodes more than one microorganism was cultured. Enterobacteriaceae were isolated in 13 (85%) of 15 episodes. Anaerobic bacteria were recovered only when operations in the pancreatico-biliary area had been performed previously. Seven episodes (26%) were related to extrahepatic disease; anaerobic bacteria (Bacteroides and Fusobacterium spp.) were isolated in five of these seven episodes. Streptococcus milleri seemed especially prominent, since this bacterium was cultured in six of seven episodes. Enterobacteriaceae were not involved in these seven episodes. Other factors predisposing to liver abscesses (15%) were diabetes mellitus n = 2), paraproteinaemia (n = I), and metastatic carcinoid (n = I). Blood cultures were positive in 65% of 23 episodes, but 40% of the positive cultures contained a smaller number of bacterial species than could be cultured from the abscess itself. Bacteria isolated from liver abscesses are related to the underlying predisposing condition. For diagnosis of the underlying condition and antibiotic therapy, puncture and bacteriologic examination of the abscess is essential.
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Affiliation(s)
- T T Lim
- Afd. Interne Geneeskunde, Academisch Medisch Centrum, Amsterdam
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