1.9-Hydroxy-6,7-dimethoxydalbergiquinol suppresses hydrogen peroxide-induced senescence in human dermal fibroblasts through induction of sirtuin-1 expression
Seok-Hee LIM ; Si-Bing LI ; Zhe-Ri ZHU ; Byung-Min CHOI
Asian Pacific Journal of Tropical Biomedicine 2021;11(2):89-96
Objective:To investigate the potential anti-aging mechanism of 9-hydroxy-6,7-dimethoxydalbergiquinol (HDDQ) on hydrogen peroxide (H2O2)-induced oxidative stress in human dermal fibroblasts (HDFs). Methods:The effect of HDDQ on cell viability was assessed by MTT assay, and the effects of HDDQ on senescence-like phenotypes were determined by senescence-associated β-galactosidase (SA-β-gal) staining, Western blotting analysis, and a cell proliferation assay. The expression level and activity of sirtuin-1 (SIRT1) induced by HDDQ were also measured. Results:HDDQ reversed senescence-like phenotypes in the oxidant-challenged model, through reducing SA-β-gal activity and promoting cell growth. Meanwhile, decreases in ac-p53, p21Cip1/WAF1, and p16Ink4a and an increase in pRb were observed. HDDQ induced the expression of SIRT1 in a concentration- and time-dependent manner. Moreover, HDDQ inhibited H2O2-induced phosphorylation of Akt by SIRT1 up-regulation and reduced SA-β-gal staining. Conclusions:HDDQ inhibits H2O2-induced premature senescence and upregulation of SIRT1 expression plays a vital role in the inhibition of the senescence phenotype in HDFs.
2.Creation of Consistent Burn Wounds: A Rat Model.
Elijah Zhengyang CAI ; Chuan Han ANG ; Ashvin RAJU ; Kong Bing TAN ; Eileen Chor Hoong HING ; Yihua LOO ; Yong Chiat WONG ; Hanjing LEE ; Jane LIM ; Shabbir M MOOCHHALA ; Charlotte A E HAUSER ; Thiam Chye LIM
Archives of Plastic Surgery 2014;41(4):317-324
BACKGROUND: Burn infliction techniques are poorly described in rat models. An accurate study can only be achieved with wounds that are uniform in size and depth. We describe a simple reproducible method for creating consistent burn wounds in rats. METHODS: Ten male Sprague-Dawley rats were anesthetized and dorsum shaved. A 100 g cylindrical stainless-steel rod (1 cm diameter) was heated to 100degrees C in boiling water. Temperature was monitored using a thermocouple. We performed two consecutive toe-pinch tests on different limbs to assess the depth of sedation. Burn infliction was limited to the loin. The skin was pulled upwards, away from the underlying viscera, creating a flat surface. The rod rested on its own weight for 5, 10, and 20 seconds at three different sites on each rat. Wounds were evaluated for size, morphology and depth. RESULTS: Average wound size was 0.9957 cm2 (standard deviation [SD] 0.1845) (n=30). Wounds created with duration of 5 seconds were pale, with an indistinct margin of erythema. Wounds of 10 and 20 seconds were well-defined, uniformly brown with a rim of erythema. Average depths of tissue damage were 1.30 mm (SD 0.424), 2.35 mm (SD 0.071), and 2.60 mm (SD 0.283) for duration of 5, 10, 20 seconds respectively. Burn duration of 5 seconds resulted in full-thickness damage. Burn duration of 10 seconds and 20 seconds resulted in full-thickness damage, involving subjacent skeletal muscle. CONCLUSIONS: This is a simple reproducible method for creating burn wounds consistent in size and depth in a rat burn model.
Animals
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Burns*
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Erythema
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Extremities
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Hot Temperature
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Humans
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Male
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Models, Animal*
;
Muscle, Skeletal
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Rats
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Rats, Sprague-Dawley
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Skin
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Viscera
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Water
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Wounds and Injuries*
3.Increased expression of galectin-9 in experimental autoimmune encephalomyelitis.
Jinhee CHO ; So Jin BING ; Areum KIM ; Hak Sun YU ; Yoon Kyu LIM ; Taekyun SHIN ; Jonghee CHOI ; Youngheun JEE
Korean Journal of Veterinary Research 2014;54(4):209-218
Experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS), reflects pathophysiologic steps in MS such as the influence of T cells and antibodies reactive to the myelin sheath, and the cytotoxic effect of cytokines. Galectin-9 (Gal-9) is a member of animal lectins that plays an essential role in various biological functions. The expression of Gal-9 is significantly enhanced in MS lesions; however, its role in autoimmune disease has not been fully elucidated. To identify the role of Gal-9 in EAE, we measured changes in mRNA and protein expression of Gal-9 as EAE progressed. Expression increased with disease progression, with a sharp rise occurring at its peak. Gal-9 immunoreactivity was mainly expressed in astrocytes and microglia of the central nervous system (CNS) and macrophages of spleen. Flow cytometric analysis revealed that Gal-9+CD11b+ cells were dramatically increased in the spleen at the peak of disease. Increased expression of tumor necrosis factor (TNF)-R1 and p-Jun N-terminal kinase (JNK) was observed in the CNS of EAE mice, suggesting that TNF-R1 and p-JNK might be key regulators contributing to the expression of Gal-9 during EAE. These results suggest that identification of the relationship between Gal-9 and EAE progression is critical for better understanding Gal-9 biology in autoimmune disease.
Animals
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Antibodies
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Astrocytes
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Autoimmune Diseases
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Biology
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Central Nervous System
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Cytokines
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Disease Progression
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Encephalomyelitis, Autoimmune, Experimental*
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Humans
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Lectins
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Macrophages
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Mice
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Microglia
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Models, Animal
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Multiple Sclerosis
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Myelin Sheath
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Phosphotransferases
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RNA, Messenger
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Spleen
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T-Lymphocytes
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Tumor Necrosis Factor-alpha
4.Syndecan-1 is a potential biomarker for triple-positive breast carcinomas in Asian women with correlation to survival.
Geok-Hoon LIM ; Puay-Hoon TAN ; Ana Richelia JARA-LAZARO ; Aye Aye THIKE ; Wey-Cheng SIM ; Von-Bing YAP ; George Wai-Cheong YIP
Singapore medical journal 2014;55(9):468-472
INTRODUCTIONWhile overexpression of syndecan-1 has been associated with aggressive breast cancer in the Caucasian population, the expression pattern of syndecan-1 in Asian women remains unclear. Triple-positive breast carcinoma, in particular, is a unique subtype that has not been extensively studied. We aimed to evaluate the role of syndecan-1 as a potential biomarker and prognostic factor for triple-positive breast carcinoma in Asian women.
METHODSUsing immunohistochemistry, staining scores of 61 triple‑positive breast carcinoma specimens were correlated with patients' clinicopathological variables such as age, ethnicity, tumour size, histological grade, lymph node status, lymphovascular invasion, associated ductal carcinoma in situ grade, recurrence and overall survival.
RESULTSSyndecan-1 had intense staining scores in triple‑positive invasive ductal breast carcinomas when compared to normal breast tissue. On multivariate analysis, syndecan-1 epithelial total percentage and immunoreactivity score showed statistical correlation with survival (p = 0.02).
CONCLUSIONThe intense staining scores of syndecan-1 and their correlation with overall survival in patients with triple-positive breast carcinoma suggest that syndecan-1 may have a role as a biological and prognostic marker in patients with this specific subtype of breast cancer.
Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Biomarkers, Tumor ; blood ; Breast Neoplasms ; blood ; classification ; mortality ; Estrogen Receptor alpha ; metabolism ; Female ; Humans ; Immunohistochemistry ; Kaplan-Meier Estimate ; Middle Aged ; Multivariate Analysis ; Prognosis ; Receptor, ErbB-2 ; metabolism ; Receptors, Progesterone ; metabolism ; Syndecan-1 ; blood ; Tissue Array Analysis ; Treatment Outcome
5.Effects of Cast Immobilisation on Skin Barrier Function.
Chin Yee WOO ; Mark Ja KOH ; Winnie Ky FUNG ; Cheri Sh CHAN ; Chong Bing CHUA ; Guan Tzu TAY ; Sanchalika ACHARYYA ; Gloria Fh CHEW ; Nicole Kl LEE ; Kevin Bl LIM
Annals of the Academy of Medicine, Singapore 2020;49(6):354-359
INTRODUCTION:
Cast immobilisation remains the mainstay of treatment for various fractures in paediatric patients, yet patients commonly complain of skin irritation and discomfort. This study aimed to perform a qualitative and quantitative evaluation of the effects of cast immobilisation on the skin of children and adolescents.
MATERIALS AND METHODS:
Patients aged 6-17 years of age with a fracture treated in a fiberglass short-arm or short-leg cast were recruited. Transepidermal water loss (TEWL), stratum corneum (SC) hydration, hair density and presence of any skin signs were assessed before and after cast. Patients were required to complete a weekly questionnaire to rate itch, malodour, warmth, and dampness of the skin under the cast.
RESULTS:
A total of 60 subjects completed the study. Thirty-six patients received a short-arm cast; 24 received a short-leg cast. Upon cast removal, TEWL was significantly increased on the volar surface of the arms and legs ( <0.05), and the dorsal surface of the arm ( <0.05). Likewise, SC hydration was significantly increased at most sites ( <0.05), except the volar surface of the leg ( = 0.513). There was no change in hair density. Throughout the duration of casting, there was an increase in itch and malodour scores.
CONCLUSION
Moderate but significant changes in TEWL, SC hydration and subjective symptoms were observed during the duration of cast immobilisation, demonstrating that cast immobilisation for up to 4 weeks exerts moderate adverse impact on patients' skin. Further studies to explore the use of better materials for cast immobilisation to improve skin barrier function and overall patient satisfaction are warranted.
6.Development of the fellowship program in musculoskeletal rehabilitation medicine at Philippine General Hospital in the University of the Philippines Manila
Monalisa L. Lim-Dungca ; Dorothy Dy Ching Bing-Agsaoay ; Jose Alvin P. Mojica
Acta Medica Philippina 2022;56(4):82-88
Musculoskeletal conditions are among the leading causes of consultations in Rehabilitation Medicine. A fellowship program in Musculoskeletal Rehabilitation Medicine was proposed to enrich physiatrists’ knowledge and skills in evaluating and managing musculoskeletal conditions. In this paper, we shared the process of developing the curriculum of the fellowship program, which was proposed to and eventually approved by the Postgraduate Institute of Medicine, College of Medicine, University of the Philippines Manila.
A core group of consultants, considered as experienced clinicians and educators in Musculoskeletal Rehabilitation Medicine in the study institution, designed the program from the scope of training to learning competencies, outcomes, and assessment methods.
To our knowledge, developing the fellowship program in this constantly evolving area in Rehabilitation Medicine is the first of its kind in the Philippines and a milestone in the history of postgraduate education in the longest-running training program for aspiring physiatrists.
Physical and Rehabilitation Medicine
7.The expression of Foxp3 protein by retroviral vector-mediated gene transfer of Foxp3 in C57BL/6 mice.
Insun HWANG ; Danbee HA ; So Jin BING ; Kyong Leek JEON ; Ginnae AHN ; Dae Seung KIM ; Jinhee CHO ; Jaehak LIM ; Sin Hyeog IM ; Kyu Kye HWANG ; Youngheun JEE
Korean Journal of Veterinary Research 2012;52(3):183-191
The maintenance of peripheral immune tolerance and prevention of chronic inflammation and autoimmune disease require CD4+CD25+ T cells (regulatory T cells). The transcription factor Foxp3 is essential for the development of functional, regulatory T cells, which plays a prominent role in self-tolerance. Retroviral vectors can confer high level of gene transfer and transgene expression in a variety of cell types. Here we observed that following retroviral vector-mediated gene transfer of Foxp3, transductional Foxp3 expression was increased in the liver, lung, brain, heart, muscle, spinal cord, kidney and spleen. One day after vector administration, high levels of transgene and gene expression were observed in liver and lung. At 2 days after injection, transductional Foxp3 expression level was increased in brain, heart, muscle and spinal cord, but kidney and spleen exhibited a consistent low level. This finding was inconsistent with the increase in both CD4+CD25+ T cell and CD4+Foxp3+ T cell frequencies observed in peripheral immune cells by fluorescence-activated cell-sorting (FACS) analysis. Retroviral vector-mediated gene transfer of Foxp3 did not lead to increased numbers of CD4+CD25+ T cell and CD4+Foxp3+ T cell. These results demonstrate the level and duration of transductional Foxp3 gene expression in various tissues. A better understanding of Foxp3 regulation can be useful in dissecting the cause of regulatory T cells dysfunction in several autoimmune diseases and raise the possibility of enhancing suppressive functions of regulatory T cells for therapeutic purposes.
Animals
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Autoimmune Diseases
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Brain
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Gene Expression
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Heart
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Immune Tolerance
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Inflammation
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Kidney
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Liver
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Lung
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Mice
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Muscles
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Spinal Cord
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Spleen
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T-Lymphocytes
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T-Lymphocytes, Regulatory
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Transcription Factors
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Transgenes
;
Zidovudine
8.Assessing the knowledge, attitude and practice of osteoporosis among Singaporean women aged 65 years and above at two SingHealth polyclinics.
Dypti LULLA ; Chiang Wen TEO ; XiaoYou SHEN ; Zhi Bing Julian LOI ; Khai Wen QUEK ; Hosanna Liha Anak LIS ; Sheila Anthony KOH ; Eric Tao CHAN ; Sarah Woon Ching LIM ; Lian Leng LOW
Singapore medical journal 2021;62(4):190-194
INTRODUCTION:
Singapore has one of the world's most rapidly ageing populations. Osteoporosis is associated with significant morbidity and mortality from hip fractures in the elderly. This pilot study aims to evaluate the knowledge, attitude and practice of osteoporosis among Singaporean women aged ≥ 65 years, and assess barriers to osteoporosis screening.
METHODS:
We conducted a cross-sectional survey of 99 English-speaking women aged ≥ 65 years at two SingHealth polyclinics by convenience sampling. The validated Osteoporosis Prevention and Awareness Tool was used to assess their knowledge about osteoporosis prevention and awareness and perceived barriers to osteoporosis screening. Osteoporosis health education was provided, and bone mineral density (BMD) screening was offered to all participants.
RESULTS:
The response rate was 91.6%. The majority of the participants (54.5%) had low knowledge of osteoporosis, and only 12.1% had high knowledge scores. Higher education levels were associated with higher knowledge scores (p = 0.018). Although participants with higher knowledge scores were more willing to undergo osteoporosis screening, these findings did not reach statistical significance (p = 0.067). The top reasons for declining BMD testing were misconceptions that lifestyle management is sufficient to prevent osteoporosis, poor awareness and knowledge of the disease, and the perceived high cost of BMD testing.
CONCLUSION
Interventions should focus on osteoporosis education and, eventually, BMD screening for less-educated patients. Health education should rectify common misconceptions of the disease, increase awareness of osteoporosis and improve screening rates.
9.Pluripotent stem cells secrete Activin A to improve their epiblast competency after injection into recipient embryos.
Jinzhu XIANG ; Suying CAO ; Liang ZHONG ; Hanning WANG ; Yangli PEI ; Qingqing WEI ; Bingqiang WEN ; Haiyuan MU ; Shaopeng ZHANG ; Liang YUE ; Genhua YUE ; Bing LIM ; Jianyong HAN
Protein & Cell 2018;9(8):717-728
It is not fully clear why there is a higher contribution of pluripotent stem cells (PSCs) to the chimera produced by injection of PSCs into 4-cell or 8-cell stage embryos compared with blastocyst injection. Here, we show that not only embryonic stem cells (ESCs) but also induced pluripotent stem cells (iPSCs) can generate F0 nearly 100% donor cell-derived mice by 4-cell stage embryo injection, and the approach has a "dose effect". Through an analysis of the PSC-secreted proteins, Activin A was found to impede epiblast (EPI) lineage development while promoting trophectoderm (TE) differentiation, resulting in replacement of the EPI lineage of host embryos with PSCs. Interestingly, the injection of ESCs into blastocysts cultured with Activin A (cultured from 4-cell stage to early blastocyst at E3.5) could increase the contribution of ESCs to the chimera. The results indicated that PSCs secrete protein Activin A to improve their EPI competency after injection into recipient embryos through influencing the development of mouse early embryos. This result is useful for optimizing the chimera production system and for a deep understanding of PSCs effects on early embryo development.
Activins
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metabolism
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Animals
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Cells, Cultured
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Embryonic Development
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Germ Layers
;
metabolism
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Mice
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Pluripotent Stem Cells
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cytology
;
metabolism