MyMedR

Fulltext Glove Manufacturing: Opportunities and Challenges in Control Engineering

Tan AH

IFAC Pap OnLine, 2022;55(1):872-877.

PMID: 38620994 DOI: 10.1016/j.ifacol.2022.04.143

The glove manufacturing industry has seen tremendous growth recently, spurred on by the COVID-19 pandemic. A long-standing shortage of supply of disposable medical gloves has highlighted an urgent need to increase production capacity. This requires glove manufacturers to be quick in adopting best practices, in line with Industry 4.0, in order to optimize various aspects of the industry. Unfortunately, information available in the existing literature is, however, limited due to the confidential nature of the majority of research in this area. This article discusses some opportunities and challenges related to this important chemical industry, from the perspective of control engineering. These insights can point to some interesting directions of future work.

Optimization of neural networks using variable structure systems

Mohseni SA, Tan AH

IEEE Trans Syst Man Cybern B Cybern, 2012 Dec;42(6):1645-53.

PMID: 22665508 DOI: 10.1109/TSMCB.2012.2197610

This paper proposes a new mixed training algorithm consisting of error backpropagation (EBP) and variable structure systems (VSSs) to optimize parameter updating of neural networks. For the optimization of the number of neurons in the hidden layer, a new term based on the output of the hidden layer is added to the cost function as a penalty term to make optimal use of hidden units related to weights corresponding to each unit in the hidden layer. VSS is used to control the dynamic model of the training process, whereas EBP attempts to minimize the cost function. In addition to the analysis of the imposed dynamics of the EBP technique, the global stability of the mixed training methodology and constraints on the design parameters are considered. The advantages of the proposed technique are guaranteed convergence, improved robustness, and lower sensitivity to initial weights of the neural network.

Historical perspective: The pros and cons of conventional outcome measures in Parkinson's disease

Lim SY, Tan AH

Parkinsonism Relat Disord, 2018 Jan;46 Suppl 1:S47-S52.

PMID: 28793970 DOI: 10.1016/j.parkreldis.2017.07.029

BACKGROUND: Conventional outcome measures (COMs) in Parkinson's disease (PD) refer to rating scales, questionnaires, patient diaries and clinically-based tests that do not require specialized equipment.

METHODS: It is timely at this juncture - as clinicians and researchers begin to grapple with the "invasion" of digital technologies - to review the strengths and weaknesses of these outcome measures.

RESULTS: This paper discusses advances (including an enhanced understanding of PD itself, and the development of clinimetrics as a field) that have led to improvements in the COMs used in PD; their strengths and limitations; and factors to consider when selecting and using a measuring instrument.

CONCLUSIONS: It is envisaged that in the future, a combination of COMs and technology-based objective measures will be utilized, with different methods having their own strengths and weaknesses. Judgement is required on the part of the clinician and researcher in terms of which instrument(s) are appropriate to use, depending on the particular clinical or research setting or question.

Movement Disorder Rounds: Learning through observation, building on collective experiences

Tan AH, Gatto EM

Parkinsonism Relat Disord, 2023 Apr 05.

PMID: 37045676 DOI: 10.1016/j.parkreldis.2023.105396

Osmotic Demyelination Syndrome With Evolving Movement Disorders

Tan AH, Lim SY, Ng RX

JAMA Neurol, 2018 07 01;75(7):888-889.

PMID: 29799978 DOI: 10.1001/jamaneurol.2018.0983

Teaching Video NeuroImages: Purposeless groaning in progressive supranuclear palsy

Low SC, Tan AH, Lim SY

Neurology, 2017 01 03;88(1):e9.

PMID: 28025406 DOI: 10.1212/WNL.0000000000003465

Fulltext Improvement of "Bouncy Gait" in Lance-Adams Syndrome with Perampanel

Lim SY, Jasti DB, Tan AH

Cureus, 2020 Jan 25;12(1):e6773.

PMID: 32117660 DOI: 10.7759/cureus.6773

Lance-Adams syndrome (LAS) is chronic post-hypoxic myoclonus that is often associated with sudden lapses in muscle tone (negative myoclonus) in the legs, causing a disabling "bouncy gait." Given its relative rarity, there are no controlled treatment studies of LAS. The majority of cases require polypharmacy management, with an incomplete response. "Bouncy gait," in particular, is notoriously medication-refractory. Here, we report a patient with long-standing LAS who improved markedly when low-dose perampanel was added to his existing treatment regime consisting of clonazepam, levetiracetam, sodium valproate, and acetazolamide.

Levodopa and Parkinson Disease-Myths Revisited

Lim SY, Poewe W, Tan AH

JAMA Neurol, 2017 10 01;74(10):1270.

PMID: 28973082 DOI: 10.1001/jamaneurol.2017.2560

Deep brain stimulation in Dopa-Responsive Parkinsonism - Look out for red flags: Expert commentary

Lim SY, Tan AH, Tay YW

Parkinsonism Relat Disord, 2023 Jan 10.

PMID: 36641339 DOI: 10.1016/j.parkreldis.2022.105276

Radiological classification of meniscocapsular tears of the anterolateral portion of the lateral meniscus of the knee

George J, Saw KY, Ramlan AA, Packya N, Tan AH, Paul G

Australas Radiol, 2000 Feb;44(1):19-22.

PMID: 10761254

In an arthroscopic-MRI correlation study of acute injuries to the knee it was found that anterolateral meniscocapsular separations of the lateral aspect of the knee were missed on MRI reporting. Eighty sports-related injuries of the knee were seen by experienced orthopaedic surgeons at the University of Malaya Medical Centre and at the National Sports Centre, Malaysia from January 1996 to July 1997. Fifty of the patients were suspected to have meniscal tears that were either lateral or medial on clinical examination and they were sent for MRI. Many of these patients were tertiary referrals. Magnetic resonance imaging examinations in 27 of the 50 patients were reported as not showing any intrasubstance or obvious meniscocapsular tears, but arthroscopy performed on them revealed anterolateral meniscocapsular tears of the lateral meniscus of varying degrees in nine of these patients. In retrospect the tears could be seen on MRI, and a pattern to the tears was noted and classified as follows. Type 0, normal; type 1, torn inferior or superior meniscocapsular attachment; type 2, both meniscofemoral and meniscotibial ligaments torn but with minimal separation of meniscus and capsule by fluid or synovitis; and type 3, marked separation of meniscus and capsule by fluid (> 3 mm). Ten patients who did not undergo arthroscopy for various personal and financial reasons underwent MRI which showed type 1 and type 2 tears, and were treated conservatively. These patients were all asymptomatic after 4-6 weeks with regard to clinical signs, suggesting a lateral meniscal tear. Magnetic resonance imaging therefore does reveal minor degrees of meniscocapsular tears anterolaterally when one understands the normal anatomy in this region.

Failed magnetic resonance imaging examinations due to claustrophobia

Sarji SA, Abdullah BJ, Kumar G, Tan AH, Narayanan P

Australas Radiol, 1998 Nov;42(4):293-5.

PMID: 9833363

A recognized cause of incomplete or cancelled MRI examinations is anxiety and claustrophobic symptoms in patients undergoing MR scanning. This appears to be a problem in many MRI centres in Western Europe and North America, where it is said to be costly in terms of loss of valuable scan time, and has led to researchers suggesting several anxiety-reducing approaches for MRI. To determine the incidence of failed MRI examination among our patients and if there are any associations with a patient's sex, age and education level, we studied claustrophobia that led to premature termination of the MRI examination in the University Malaya Medical Centre (UMMC) in 3324 patients over 28 months. The incidence of failed MRI examinations due to claustrophobia in the UMMC was found to be only 0.54%. There are associations between claustrophobia in MRI with the patients' sex, age and level of education. The majority of those affected were male patients and young patients in the 25-45-years age group. The patients' education level appears to be the strongest association with failed MRI examinations due to claustrophobia, where the majority of the affected were highly educated individuals. Claustrophobia in MRI is more of a problem among the educated individuals or patients from a higher socio-economic group, which may explain the higher incidence in Western European and North American patients.

Brief Clinical Rating Scales Should Not Be Overlooked

Lim SY, Lim KB, Hor JW, Tan AH

Mov Disord, 2020 10;35(10):1884-1885.

PMID: 33068479 DOI: 10.1002/mds.28274

Fulltext Purposeless Groaning in Parkinson's Disease

Lim SY, Tan AH, Lim JL, Ahmad-Annuar A

J Mov Disord, 2018 May;11(2):87-88.

PMID: 29860787 DOI: 10.14802/jmd.18004

Purposeless groaning has been reported in advanced progressive supranuclear palsy. We present a case of purposeless groaning occurring as a primary complaint in a patient with advanced Parkinson's disease. Purposeless groaning is thought to be a manifestation of disinhibition and perseveration due to frontal-subcortical dysfunction. Proper recognition of this phenomenon will help clinicians to avoid unnecessary investigations and treatment (e.g., prescription of opioid medications).

Methylmalonic Aciduria: A Treatable Disorder of Which Adult Neurologists Need to Be Aware

Tan AH, Mah JSY, Thong MK, Lim SY

Mov Disord Clin Pract, 2015 09 16;3(1):104-105.

PMID: 30713905 DOI: 10.1002/mdc3.12237

Fulltext Probiotics for Parkinson's disease: Current evidence and future directions

Tan AH, Hor JW, Chong CW, Lim SY

JGH Open, 2021 Apr;5(4):414-419.

PMID: 33860090 DOI: 10.1002/jgh3.12450

The gut-brain axis is a hot topic in Parkinson's disease (PD). It has been postulated that gut pathogens and dysbiosis can contribute to peripheral inflammatory states or trigger downstream metabolic effects that exacerbate the neurodegenerative process in PD. Several preclinical and clinical studies have demonstrated disrupted intestinal permeability, intestinal inflammation, altered gut microbiome, and reduced fecal short-chain fatty acids in PD. In this regard, microbial-directed therapies such as probiotics are emerging as potential therapeutic options. Probiotic supplementation is postulated to confer a variety of health benefits due to the diverse functions of these live microorganisms, including inhibition of pathogen colonization, modulation/"normalization" of the microbiome and/or its function, immunomodulatory effects (e.g. reducing inflammation), and improved host epithelial barrier function. Interestingly, several PD animal model studies have demonstrated the potential neuroprotective effects of probiotics in reducing dopaminergic neuronal degeneration. Notably, two randomized placebo-controlled trials have provided class I evidence for probiotics as a treatment for constipation in PD. However, the effects of probiotics on other PD aspects, such as motor disability and cognitive function, and its long-term efficacy (including effects on PD drug absorption in the gut) have not been investigated adequately. Further targeted animal and human studies are also warranted to understand the mechanisms of actions of probiotics in PD and to tailor probiotic therapy based on individual host profiles to improve patient outcomes in this disabling disorder.

Advice to People with Parkinson's in My Clinic: Probiotics and Prebiotics

Hor JW, Toh TS, Lim SY, Tan AH

J Parkinsons Dis, 2024 Aug 23.

PMID: 39213091 DOI: 10.3233/JPD-240172

There is increasing evidence that microbial-based therapies can be useful in people with Parkinson's disease (PD). In this viewpoint, we provide a state-of-the-art review of the clinical and pre-clinical evidence for probiotics and prebiotics in PD. Currently, short-term clinical studies, including double-blind placebo-controlled randomized clinical trials, have demonstrated safety, and efficacy primarily in improving constipation-related symptoms. Pre-clinical studies consistently reported improvements in a range of biological markers and outcomes, including evidence for attenuation of gut dysfunction and neuroprotection. Bacteria from the genus Lactobacillus and Bifidobacterium have been the most frequently studied both in clinical and pre-clinical probiotics studies, while research into prebiotics is still limited and primarily involved resistant starch and fructooligosaccharides. We provide practical suggestions for clinicians on how to advise patients in the clinic regarding these popular treatments, and important caveats to be aware of. Finally, areas for further advancements are highlighted. It is envisaged that in the future, microbial-based therapies may benefit from personalization based on an enhanced understanding of a whole range of host factors and host-microbiome interactions.

Opsoclonus-myoclonus-ataxia syndrome associated with dengue virus infection

Tan AH, Linn K, Sam IC, Tan CT, Lim SY

Parkinsonism Relat Disord, 2015 Feb;21(2):160-1.

PMID: 25443556 DOI: 10.1016/j.parkreldis.2014.11.009

Sensory nerves are frequently involved in the spectrum of fisher syndrome

Shahrizaila N, Goh KJ, Kokubun N, Tan AH, Tan CY, Yuki N

Muscle Nerve, 2014 Apr;49(4):558-63.

PMID: 23893512 DOI: 10.1002/mus.23973

Differing patterns of neurophysiological abnormalities have been reported in patients with Fisher syndrome. Fisher syndrome is rare, and few series have incorporated prospective serial studies to define the natural history of nerve conduction studies in Guillain-Barré syndrome.

Causative Pathogens of Febrile Neutropaenia in Children Treated for Acute Lymphoblastic Leukaemia

Lam JC, Chai JY, Wong YL, Tan NW, Ha CT, Chan MY, et al.

Ann Acad Med Singap, 2015 Nov;44(11):530-4.

PMID: 27089960

INTRODUCTION: Treatment of acute lymphoblastic leukaemia (ALL) using intensive chemotherapy has resulted in high cure rates but also substantial morbidity. Infective complications represent a significant proportion of treatment-related toxicity. The objective of this study was to describe the microbiological aetiology and clinical outcome of episodes of chemotherapy-induced febrile neutropaenia in a cohort of children treated for ALL at our institution.

MATERIALS AND METHODS: Patients with ALL were treated with either the HKSGALL93 or the Malaysia-Singapore (Ma-Spore) 2003 chemotherapy protocols. The records of 197 patients who completed the intensive phase of treatment, defined as the period of treatment from induction, central nervous system (CNS)-directed therapy to reinduction from June 2000 to January 2010 were retrospectively reviewed.

RESULTS: There were a total of 587 episodes of febrile neutropaenia in 197 patients, translating to an overall rate of 2.98 episodes per patient. A causative pathogen was isolated in 22.7% of episodes. An equal proportion of Gram-positive bacteria (36.4%) and Gram-negative bacteria (36.4%) were most frequently isolated followed by viral pathogens (17.4%), fungal pathogens (8.4%) and other bacteria (1.2%). Fungal organisms accounted for a higher proportion of clinically severe episodes of febrile neutropaenia requiring admission to the high-dependency or intensive care unit (23.1%). The overall mortality rate from all episodes was 1.5%.

CONCLUSION: Febrile neutropaenia continues to be of concern in ALL patients undergoing intensive chemotherapy. The majority of episodes will not have an identifiable causative organism. Gram-positive bacteria and Gram-negative bacteria were the most common causative pathogens identified. With appropriate antimicrobial therapy and supportive management, the overall risk of mortality from febrile neutropaenia is extremely low.

Fulltext The Association Between Bullous Pemphigoid and Neurological Disorders in A Selected Malaysian Population

Kwan Z, Lai YN, Ch'ng CC, Tan AH, Tan LL, Robinson S, et al.

Med J Malaysia, 2015 Apr;70(2):81-5.

PMID: 26162382 MyJurnal

BACKGROUND: An association of bullous pemphigoid with neurological disorders has been reported. The objectives of this study were to review the clinical characteristics of patients with bullous pemphigoid and compare the association between bullous pemphigoid and various neurological disorders and comorbidities.

METHODS: This was a retrospective case-control study involving 43 patients with bullous pemphigoid and 43 age-, sex- and ethnicity-matched controls.

RESULTS: There was a statistically significant association between bullous pemphigoid and neurological disorders [Odds Ratio (OR) = 3.5, 95% Confidence Interval (CI) 1.3 to 9.2, p=0.011 and adjusted OR=3.5, 95% CI 1.2-10.3, p=0.026], in particular for dementia (p=0.002). Although stroke was more common among patients with bullous pemphigoid, this association was not statistically significant with OR of 1.9 (95% CI 0.7 to 5.2) and adjusted OR of 2.1 (95% CI 0.6 to 7.2). Similarly both ischaemic stroke (OR 1.5, 95% CI 0.5 to 4.2) and haemorrhagic stroke (OR 1.5, 95% CI 0.2 to 9.7) were more common. Other neurological disorders more common among patients with bullous pemphigoid were Parkinson's disease and epilepsy. Dyslipidaemia was significantly less common among patients with bullous pemphigoid (OR 0.4, 95% CI 0.1 to 0.9, p=0.033).

CONCLUSION: A combination of an inflammatory process, prothrombotic state and endothelial activation leads to an increased frequency of neurological disorders among patients with bullous pemphigoid. Thus, a holistic approach to patient care, including screening for dementia and control of comorbidities, should be practised as bullous pemphigoid affects more than just the skin.

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