1.The Immunologic Properties of Undifferentiated Stem Cells from Human Exfoliated Deciduous Teeth (SHED) and Its Potential Application in Bone Regeneration
Nurul AA ; Tan SJ ; Asiah AB ; Norliana G ; Nor Shamsuria O
The International Medical Journal Malaysia 2013;12(1):19-26
Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic
cells capable of differentiating into osteoblasts and inducing bone formation. It is a potential alternative for
stem cell bone regeneration therapy. However, stem cell therapy carries the risk of immune rejection mediated
by inflammatory cytokines of the human defense system. Objective: This preliminary research studies the
interaction between SHED and the immune system by determining the inflammatory cytokines profile and
osteogenic potential of SHED. Methods: Human fetal osteoblasts (hFOb) cell line and isolated SHED were
cultured and total RNA was extracted, followed by reverse transcription cDNA synthesis. Semi-quantitative
reverse transcription PCR and Multiplex PCR were performed to detect the expression levels of OPG/RANKL and
TNF-α, IL-1β, IL-6, IL-8 and TGF-β in both cell types. Results: Analysis showed that SHED expressed significantly
lower amounts of IL-1β, IL-6, and IL-8 compared to hFOB. IL-1β is a potent bone-resorbing factor, while IL-6
and IL-8 induce osteoclastogenesis and osteolysis respectively. SHED did not express TNF-α which stimulates
osteoclastic activity. SHED demonstrated high OPG/RANKL ratio, in contrast with that of marrow stem cells
described in previous studies. Our findings suggest that SHED may have improved immunomodulatory profile in
terms of promoting relatively lower inflammatory reaction during transplant and enhancing bone regeneration.
Conclusion: SHED has a potential to be a good source of osteoblasts for bone regeneration therapy. Further
studies on the immunomodulatory properties of SHED-derived osteoblasts are necessary to enable stem cell
therapy in immunocompetent hosts.
2.Depression, anxiety and stress among patients with
Tan KC ; Chan GC ; Eric H ; Maria AI ; Norliza MJ ; Oun BH ; Sheerine MT ; Wong SJ ; Liew SM
Malaysian Family Physician 2015;10(2):9-21
Background: The incidence of diabetes mellitus is ever increasing. Individuals with diabetes mellitus
may have concurrent mental health disorders and are shown to have poorer disease outcomes. The
objectives of this study were to determine the prevalence of depression, anxiety and stress (DAS) in
diabetes patients aged 20 years or more in the primary care setting.
Methods: This was a cross-sectional study involving the use of self-administered questionnaire
conducted in eight primary care private and government clinics in Pulau Pinang and Melaka,
Malaysia. The validated DASS-21 questionnaire was used as a screening tool for the symptoms of
DAS. Prior permission was obtained from the patients and, clearance from ethical committee was
obtained before the start of the study. Data analysis was done using SPSS statistical software.
Results: A total of 320 patients with diabetes from eight centres were enrolled via convenience
sampling. Sample size was calculated using the Kish’s formula. The prevalence of DAS among patients
with diabetes from our study was 26.6%, 40% and 19.4%, respectively. Depression was found to
be significantly associated with marital status and family history of DAS; anxiety was significantly
associated with monthly household income, presence of co-morbidities and family history of DAS;
and stress was significantly associated with occupation and family history of DAS.
Conclusions: The prevalence of DAS was higher in patients with diabetes compared with the
general community. We recommend to routinely screen all patients with diabetes using the DASS-21
questionnaire because it is easy to perform and inexpensive.
3.Triaging Primary Care Patients Referred for Chest Pain to Specialist Cardiology Centres: Efficacy of an Optimised Protocol.
Francine Cl TAN ; Jonathan YAP ; John C ALLEN ; Olivia TAN ; Swee Yaw TAN ; David B MATCHAR ; Terrance Sj CHUA
Annals of the Academy of Medicine, Singapore 2018;47(2):56-62
INTRODUCTION:
Patients referred for chest pain from primary care have increased, along with demand for outpatient cardiology consultations. We evaluated 'Triage Protocol' that implements standardised diagnostic testing prior to patients' first cardiology consultation.
MATERIALS AND METHODS:
Under the 'Triage Protocol', patients referred for chest pain were pretriaged using a standardised algorithm and subsequently referred for relevant functional diagnostic cardiology tests before their initial cardiology consultation. At the initial cardiology consultation scheduled by the primary care provider, test results were reviewed. A total of 522 triage patients (mean age 55 ± 13, male 53%) were frequency-matched by age, gender and risk cohort to 289 control patients (mean age: 56 ± 11, male: 52%). Pretest risk of coronary artery disease was defined according to a Modified Duke Clinical Score (MDCS) as low (<10), intermediate (10-20) and high (>20). The primary outcome was time from referral to diagnosis (days). Secondary outcomes were total visits, discharge rate at first consultation, patient cost and adverse cardiac outcomes.
RESULTS:
The 'Triage Protocol' resulted in shorter times from referral to diagnosis (46 vs 131 days; <0.0001) and fewer total visits (2.4 vs 3.0; <0.0001). However, triage patients in low-risk groups experienced higher costs due to increased testing (S$421 vs S$357, = 0.003). Adverse cardiac event rates under the 'Triage Protocol' indicated no compromise to patient safety (triage vs control: 0.57% vs 0.35%; = 1.000).
CONCLUSION
By implementing diagnostic cardiac testing prior to patients' first specialist consultation, the 'Triage Protocol' expedited diagnosis and reduced subsequent visits across all risk groups in ambulatory chest pain patients.
Algorithms
;
Cardiology Service, Hospital
;
Chest Pain
;
therapy
;
Clinical Protocols
;
Female
;
Humans
;
Male
;
Middle Aged
;
Primary Health Care
;
Treatment Outcome
;
Triage
;
methods
4.Application of single sperm sequencing for preimplantation genetic testing of male patient with achondroplasia.
Yuan LYU ; Chuang LI ; Feifei ZHOU ; Jesse LI-LING ; Jichun TAN ; Caixia LIU
Chinese Journal of Medical Genetics 2020;37(9):929-933
OBJECTIVE:
To assess the value of single sperm sequencing in preimplantation genetic diagnosis.
METHODS:
A male patient with achondroplasia due to a de novo FGFR3 variant was subjected to single sperm isolation and sequencing. Twenty single sperm samples were isolated by mechanical immobilization, and their whole genome was amplified. PCR primers were designed for the variant site and 25 flanking single nucleotide polymorphism (SNP) loci, and the PCR products were sequenced to determine the chromosomal haplotype which did not harbor the pathogenic variant. Biopsy samples of 12 embryonic trophoblasts were taken. Following whole genome amplification, high-throughput sequencing was carried out to detect the carrier status of the embryos. Wild type blastocysts were selected for transplantation. Amniotic fluid samples were taken at 19 weeks of gestation to confirm the status of the fetus.
RESULTS:
Eight SNP were selected by single sperm sequencing, with which the haplotypes were successfully constructed. Preimplantation genetic testing indicated that 5 embryos have carried the pathogenic variant and 7 did not. Testing of amniotic fluid sample during the second trimester of pregnancy confirmed that the fetus did not carry the FGFR3 gene c.1138G>A variant.
CONCLUSION
For male patients carrying de novo pathogenic variants, SNP sites can be selected through single sperm sequencing, and haplotypes can be constructed by linkage analysis for preimplantation genetic diagnosis.
5.Ethnic Differences and Trends in ST-Segment Elevation Myocardial Infarction Incidence and Mortality in a Multi-Ethnic Population.
Huili ZHENG ; Pin Pin PEK ; Andrew Fw HO ; Win WAH ; Ling Li FOO ; Jessie Q LI ; Vasuki UTRAVATHY ; Terrance Sj CHUA ; Huay Cheem TAN ; Marcus Eh ONG
Annals of the Academy of Medicine, Singapore 2019;48(3):75-85
INTRODUCTION:
This study aimed to compare the incidence and mortality of ST-segment elevation myocardial infarction (STEMI) across the 3 main ethnic groups in Singapore, determine if there is any improvement in trends over the years and postulate the reasons underlying the ethnic disparity.
MATERIALS AND METHODS:
This study consisted of 16,983 consecutive STEMI patients who sought treatment from all public hospitals in Singapore from 2007 to 2014.
RESULTS:
Compared to the Chinese (58 per 100,000 population in 2014), higher STEMI incidence rate was consistently observed in the Malays (114 per 100,000 population) and Indians (126 per 100,000 population). While the incidence rate for the Chinese and Indians remained relatively stable over the years, the incidence rate for the Malays rose slightly. Relative to the Indians (30-day and 1-year all-cause mortality at 9% and 13%, respectively, in 2014), higher 30-day and 1-year all-cause mortality rates were observed in the Chinese (15% and 21%) and Malays (13% and 18%). Besides the Malays having higher adjusted 1-year all-cause mortality, all other ethnic disparities in 30-day and 1-year mortality risk were attenuated after adjusting for demographics, comorbidities and primary percutaneous coronary intervention.
CONCLUSION
It is important to continuously evaluate the effectiveness of existing programmes and practices as the aetiology of STEMI evolves with time, and to strike a balance between prevention and management efforts as well as between improving the outcome of "poorer" and "better" STEMI survivors with finite resources.
6.Pre-Operative Embolisation of Musculoskeletal Tumours - A Single Centre Experience
Wong SJ, MBChB ; Urlings T, MD ; Seng C, FRCS ; Leong S, FFR RCSI ; Tan BS, FRCR ; Tan MH, FRCS
Malaysian Orthopaedic Journal 2020;14(No.1):42-48
Introduction:The management of musculoskeletal tumours is complex and requires a multi-disciplinary approach. Preoperative embolisation can be often employed to reduce intra-operative blood loss and complication rates from surgery. We report our experience with the safety, technical success and efficacy of pre-operative embolisation in musculoskeletal tumours. Materials and Methods:Thirteen consecutive patients who underwent pre-operative embolisation of a musculoskeletal tumour followed by surgical intervention at our institution from May 2012 to January 2016 were enrolled into the study. Patient demographics, tumour characteristics, embolisation techniques and type of surgery were recorded. Technical success of embolisation, amount of blood loss during surgery and transfusion requirements were estimated. Results: There were five female and eight male patients who underwent pre-operative embolisation during the study period. The age ranged between 16 to 68 years, and the median age was 54. Technical success was achieved in all patients. Mean intra-operative blood loss was 1403ml, with a range of 150ml to 6900ml. Eight patients (62%) required intra-operative blood products of packed red blood cells and fresh frozen plasma. No major complications occurred during embolisation. Conclusion: Pre-operative trans-arterial embolisation is feasible and safe for a variety of large and hypervascular musculoskeletal tumours. Our small series suggests that preoperative embolisation could contribute to the reduction of the intra-operative and post-operative blood product transfusion. It should be considered as a pre-operative adjunct for major tumour resections with a high risk of bleeding. The use of the haemoglobin gap complemented the assessment of perioperative blood loss.
7.Progresses in therapeutic strategies for thymic rejuvenation.
Jian-Xin TAN ; Ya-Jun WANG ; Xi-Ke ZHU
Acta Physiologica Sinica 2016;68(1):75-86
The thymus is a vital primary lymphoid organ that provides unique microenvironments for the proliferation, differentiation, and maturation of T cells. With advancing age, however, the thymus gradually undergoes age-related involution and reduction in immune function, which are characterized by decreases in tissue size, cellularity, and naïve T cell output. This dynamic process leads to the reduced efficacy of the immune system with age and contributes to the increased susceptibility to infection, autoimmune disease, and cancer. In addition, bone marrow transplantation, radio-chemotherapy and virus infection also impair the thymus and give rise to the decline in immune function. Therefore, understanding the molecular mechanisms involved in age-related thymic involution and development of novel therapeutic strategies for thymic rejuvenation have gained considerable interests in recent years. This review emphasizes thymic microenvironments and thymocyte-stromal cell interactions and summarizes our current knowledge about thymic rejuvenation in terms of sex steroid, cytokines, growth factors, hormones, transcription factors, cell graft, and microRNAs. At the end of each discussion, we also highlight unanswered issues and describe possible future research directions.
Aging
;
Cell Differentiation
;
Cytokines
;
Gonadal Steroid Hormones
;
Hormones
;
Humans
;
Intercellular Signaling Peptides and Proteins
;
Rejuvenation
;
Stromal Cells
;
T-Lymphocytes
;
Thymus Gland