1.Transplantation of Neural Progenitor Cells Derived from Stem Cells from Apical Papilla Through Small-Molecule Induction in a Rat Model of Sciatic Nerve Injury
Junhao KOH ; Junqing LIU ; Chi Him POON ; Jun KANG ; Mohammed S. BASABRAIN ; Lee Wei LIM ; Chengfei ZHANG
Tissue Engineering and Regenerative Medicine 2024;21(6):867-879
BACKGROUND:
Stem cell-based transplantation therapy holds promise for peripheral nerve injury treatment, but adult availability is limited. A cell culture protocol utilizing a small-molecule cocktail effectively reprogrammed stem cells from apical papilla (SCAPs) into neural progenitor cells, subsequently differentiating into neuron-like cells. This study aims to evaluate neural-induced SCAPs, with and without small-molecule cocktail, for sciatic nerve repair potential.
METHODS:
A scaffold-free cell sheet technique was used to construct a three-dimensional cell sheet. Subsequently, this cell sheet was carefully rolled into a tube and seamlessly inserted into a collagen conduit, which was then transplanted into a 5 mm sciatic nerve injury rat model. Functional sciatic nerve regeneration was evaluated via toe spread test, walking track analysis and gastrocnemius muscle weight. Additionally, degree of sciatic nerve regeneration was determined based on total amount of myelinated fibers.
RESULTS:
Small-molecule cocktail induced SCAPs enhanced motor function recovery, evident in improved sciatic function index and gastrocnemius muscle retention. We also observed better host myelinated fiber retention than undifferentiated SCAPs or neural-induced SCAPs without small-molecule cocktail. However, clusters of neuron-like cell bodies (surrounded by sparse myelinated fibers) were found in all cell sheet-implanted groups in the implantation region. This suggests that while the implanted cells likely survived transplantation, integration was poor and would likely hinder longterm recovery by occupying the space needed for host nerve fibers to project through.
CONCLUSION
Neural-induced SCAPs with small-molecule cocktail demonstrated promising benefits for nerve repair; further research is needed to improve its integration and optimize its potential for long-term recovery.
2.Current treatment landscape for obesity in Singapore.
Phong Ching LEE ; Chin Hong LIM ; Ravishankar ASOKKUMAR ; Marvin Wei Jie CHUA
Singapore medical journal 2023;64(3):172-181
The rising prevalence of obesity in Singapore is a harbinger for a corresponding increase in obesity-related complications such as type 2 diabetes mellitus (T2DM) and coronary heart disease. Obesity is a complex disease driven by multiple factors, and hence, treatment cannot follow a 'one-size-fits-all' approach. Lifestyle modifications involving dietary interventions, physical activity and behavioural changes remain the cornerstone of obesity management. However, similar to other chronic diseases such as T2DM and hypertension, lifestyle modifications are often insufficient on their own, hence the importance of other treatment modalities including pharmacotherapy, endoscopic bariatric therapy and metabolic-bariatric surgery. Weight loss medications currently approved in Singapore include phentermine, orlistat, liraglutide and naltrexone-bupropion. In recent years, endoscopic bariatric therapies have evolved as an effective, minimally invasive and durable therapeutic option for obesity. Metabolic-bariatric surgery remains the most effective and durable treatment for patients with severe obesity, with an average weight loss of 25%-30% after one year.
Humans
;
Singapore
;
Diabetes Mellitus, Type 2
;
Obesity
;
Obesity, Morbid
;
Bariatric Surgery
3.Morphology of Mandibular Condyle in The Population of Sarawak: A Retrospective Cross-sectional Study Using Digital Panoramic Radiograph
Tan Yy Jean ; Lim Woei Tatt ; Lee Sie Wei ; Shim Chen Kiong ; Mohamad Adam Bujang
Malaysian Journal of Medicine and Health Sciences 2023;19(No.4):258-264
Introduction: The morphology of the condyles changes naturally with age, gender, face type, occlusal force, functional load, malocclusion type, and the right and left sides. Although condylar shape and size differ throughout
populations, there have been few investigations on condylar morphology, particularly in the Malaysian population.
Methods: This retrospective, observational, cross-sectional survey was conducted at the Oral and Maxillofacial Surgery Clinic of Sarawak General Hospital from September 2021 to March 2022, involving radiographic assessment
of condylar morphology from 893 panoramic radiographs. Age, gender, ethnicity and dentition status using Eichner
index were extracted from the data. Descriptive statistics were used. Pearson’s chi-square test was used to determine
the association between the independent variables (age, gender, ethnicity and dentition status) and the shape of the
mandibular condyle. A p-value of < 0.05 was considered statistically significant. Results: Only 450 panoramic radiographs were included in this study. The condyles were outlined and grouped into four categories, namely pointed
(40.2%), round (32.8), angled (18.8), and flat (8.2%). Condylar morphology was found to be significantly associated
with gender (p<0.005) and insignificant with other independent variables. Conclusion: The findings suggest that the
most prevalent condylar morphology among the Sarawak population is the pointed shape, in contrast with other
previous studies that reported the round shape condylar morphology as the majority shape.
5.A summary of the Malaysian Clinical Practice Guidelines on the management of postmenopausal osteoporosis, 2022
Terence Ing WEI ONG ; Lee Ling LIM ; Siew Pheng CHAN ; Winnie Siew SWEE CHEE ; Alan Swee HOCK CH’NG ; Elizabeth GAR MIT CHONG ; Premitha DAMODARAN ; Fen Lee HEW ; Luqman bin IBRAHIM ; Hui Min KHOR ; Pauline Siew MEI LAI ; Joon Kiong LEE ; Ai Lee LIM ; Boon Ping LIM ; Sharmila Sunita PARAMASIVAM ; Jeyakantha RATNASINGAM ; Yew Siong SIOW ; Alexander Tong BOON TAN ; Nagammai THIAGARAJAN ; Swan Sim YEAP
Osteoporosis and Sarcopenia 2023;9(2):60-69
Objectives:
The aim of these Clinical Practice Guidelines is to provide evidence-based recommendations to assist healthcare providers in the screening, diagnosis and management of patients with postmenopausal osteoporosis (OP).
Methods:
A list of key clinical questions on the assessment, diagnosis and treatment of OP was formulated. A literature search using the PubMed, Medline, Cochrane Databases of Systematic Reviews, and OVID electronic databases identified all relevant articles on OP based on the key clinical questions, from 2014 onwards, to update from the 2015 edition. The articles were graded using the SIGN50 format. For each statement, studies with the highest level of evidence were used to frame the recommendation.
Results:
This article summarizes the diagnostic and treatment pathways for postmenopausal OP. Risk stratification of patients with OP encompasses clinical risk factors, bone mineral density measurements and FRAX risk estimates. Non-pharmacological measures including adequate calcium and vitamin D, regular exercise and falls prevention are recommended. Pharmacological measures depend on patients’ fracture risk status. Very high-risk individuals are recommended for treatment with an anabolic agent, if available, followed by an anti-resorptive agent. Alternatively, parenteral anti-resorptive agents can be used. High-risk individuals should be treated with anti-resorptive agents. In low-risk individuals, menopausal hormone replacement or selective estrogen receptor modulators can be used, if indicated. Patients should be assessed regularly to monitor treatment response and treatment adjusted, as appropriate.
Conclusions
The pathways for the management of postmenopausal OP in Malaysia have been updated. Incorporation of fracture risk stratification can guide appropriate treatment.
6.Functional improvement after inpatient rehabilitation in community hospitals following acute hospital care.
Htet Lin HTUN ; Lok Hang WONG ; Weixiang LIAN ; Jocelyn KOH ; Liang Tee LEE ; Jun Pei LIM ; Ian LEONG ; Wei Yen LIM
Annals of the Academy of Medicine, Singapore 2022;51(6):357-369
INTRODUCTION:
There are limited studies exploring functional improvement in relation to characteristics of patients who, following acute hospital care, receive inpatient rehabilitation in community hospitals. We evaluated the association of acute hospital admission-related factors with functional improvement on community hospital discharge.
METHODS:
We conducted a retrospective cohort study among patients who were transferred to community hospitals within 14-day post-discharge from acute hospital between 2016 and 2018. Modified Barthel Index (MBI) on a 100-point ordinal scale was used to assess functional status on admission to and discharge from the community hospital. We categorised MBI into 6 bands: 0-24, 25-49, 50-74, 75-90, 91-99 and 100. Multivariable logistic regression models were constructed to determine factors associated with categorical improvement in functional status, defined as an increase in at least one MBI band between admission and discharge.
RESULTS:
A total of 5,641 patients (median age 77 years, interquartile range 69-84; 44.2% men) were included for analysis. After adjusting for potential confounders, factors associated with functional improvement were younger age, a higher MBI on admission, and musculoskeletal diagnosis for the acute hospital admission episode. In contrast, a history of dementia or stroke; lower estimated glomerular filtration rate; abnormal serum albumin or anaemia measured during the acute hospital episode; and diagnoses of stroke, cardiac disease, malignancy, falls or pneumonia; and other chronic respiratory diseases were associated with lower odds of functional improvement.
CONCLUSION
Clinicians may want to take into account the presence of these high-risk factors in their patients when planning rehabilitation programmes, in order to maximise the likelihood of functional improvement.
Aftercare
;
Aged
;
Female
;
Hospitals, Community
;
Humans
;
Inpatients
;
Male
;
Patient Discharge
;
Retrospective Studies
;
Stroke/complications*
;
Stroke Rehabilitation
7.Mitochondria targeting drugs for neurodegenerative diseases-Design, mechanism and application.
Jiajia XU ; Wei DU ; Yunhe ZHAO ; Kahleong LIM ; Li LU ; Chengwu ZHANG ; Lin LI
Acta Pharmaceutica Sinica B 2022;12(6):2778-2789
Neurodegenerative diseases (NDDs) such as Alzheimer's disease (AD) and Parkinson's disease (PD) are a heterogeneous group of disorders characterized by progressive degeneration of neurons. NDDs threaten the lives of millions of people worldwide and regretfully remain incurable. It is well accepted that dysfunction of mitochondria underlies the pathogenesis of NDDs. Dysfunction of mitochondria results in energy depletion, oxidative stress, calcium overloading, caspases activation, which dominates the neuronal death of NDDs. Therefore, mitochondria are the preferred target for intervention of NDDs. So far various mitochondria-targeting drugs have been developed and delightfully some of them demonstrate promising outcome, though there are still some obstacles such as targeting specificity, delivery capacity hindering the drugs development. In present review, we will elaborately address 1) the strategy to design mitochondria targeting drugs, 2) the rescue mechanism of respective mitochondria targeting drugs, 3) how to evaluate the therapeutic effect. Hopefully this review will provide comprehensive knowledge for understanding how to develop more effective drugs for the treatment of NDDs.
8.Pericarditis and myocarditis after COVID-19 mRNA vaccination in a nationwide setting.
Jonathan YAP ; Mun Yee THAM ; Jalene POH ; Dorothy TOH ; Cheng Leng CHAN ; Toon Wei LIM ; Shir Lynn LIM ; Yew Woon CHIA ; Yean Teng LIM ; Jonathan CHOO ; Zee Pin DING ; Ling Li FOO ; Simin KUO ; Yee How LAU ; Annie LEE ; Khung Keong YEO
Annals of the Academy of Medicine, Singapore 2022;51(2):96-100
INTRODUCTION:
Despite reports suggesting an association between COVID-19 mRNA vaccination and pericarditis and myocarditis, detailed nationwide population-based data are sparsely available. We describe the incidence of pericarditis and myocarditis by age categories and sex after COVID-19 mRNA vaccination from a nationwide mass vaccination programme in Singapore.
METHODS:
The incidence of adjudicated cases of pericarditis and myocarditis following COVID-19 mRNA vaccination that were reported to the vaccine safety committee between January to July 2021 was compared with the background incidence of myocarditis in Singapore.
RESULTS:
As of end July 2021, a total of 34 cases were reported (9 pericarditis only, 14 myocarditis only, and 11 concomitant pericarditis and myocarditis) with 7,183,889 doses of COVID-19 mRNA vaccine administered. Of the 9 cases of pericarditis only, all were male except one. The highest incidence of pericarditis was in males aged 12-19 years with an incidence of 1.11 cases per 100,000 doses. Of the 25 cases of myocarditis, 80% (20 cases) were male and the median age was 23 years (range 12-55 years) with 16 cases after the second dose. A higher-than-expected number of cases were seen in males aged 12-19 and 20-29 years, with incidence rates of 3.72 and 0.98 case per 100,000 doses, respectively.
CONCLUSION
Data from the national registry in Singapore indicate an increased incidence of pericarditis and myocarditis in younger men after COVID-19 mRNA vaccination.
Adolescent
;
Adult
;
COVID-19/prevention & control*
;
COVID-19 Vaccines/adverse effects*
;
Child
;
Female
;
Humans
;
Male
;
Middle Aged
;
Myocarditis/etiology*
;
Pericarditis/etiology*
;
RNA, Messenger
;
SARS-CoV-2
;
Vaccination/adverse effects*
;
Vaccines, Synthetic
;
Young Adult
;
mRNA Vaccines
9. Pulse oximeter as a home assessment tool: Knowledge and user experience among the community in Malaysia during the COVID-19 pandemic
Siew-Keah LEE ; Jin MA ; Khai CHAN ; Yi CHEONG ; Wan HONG ; Regine ONG ; Wei TAY ; Ang-Lim CHUA
Asian Pacific Journal of Tropical Medicine 2022;15(5):213-219
Objective: To determine the degree of knowledge in the usage of pulse oximeter as a home assessment tool among the community in Malaysia. Methods: A cross-sectional survey was conducted in November 2021. The questionnaire assessed the knowledge in using pulse oximeters, user experience and opinions in using pulse oximeter as a home assessment tool during the pandemic. Results: A total of 504 respondents were included in the study, and the mean score in knowledge related to application of pulse oximetry was 73.00%, while the mean score in knowledge related to factors affecting pulse oximetry readings was only 38.51%. A total of 90.5% of the respondents recognised normal pulse rate and 88.5% knew the blood oxygen saturation levels of a healthy adult, while 69.4% recognised the definition of silent hypoxia. In addition, the majority of the respondents agreed that factors such as poor blood circulation (71.2%), excessive movements (69.8%), and hand position (60.7%) affected oximetry readings. However, 61.7%, 81.7%, 77.2% and 76.8% of the respondents could not identify nail polish, skin colour, skin thickness and tattoos as factors that may affect oximetry readings respectively. Conclusions: The respondents showed a satisfactory level of knowledge related to application of pulse oximetry, but a poor level of knowledge related to factors affecting pulse oximetry readings among the community in Malaysia. Continuous efforts in educating the community on the correct use of pulse oximeters are crucial for appropriate home assessment and avoiding unnecessary stress.
10.Development and feasibility of a mobile-based vestibular rehabilitation therapy application for healthy older adults.
Lee Huan TEE ; Wei Wei SEAH ; Christina Hui Ling CHIA ; Eng Chuan NEOH ; Peter LIM ; Sze Wong LIAW ; Peng Shorn SIEW ; Eu Chin HO
Annals of the Academy of Medicine, Singapore 2022;51(8):514-516


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