1.Does erroneous differentiation of tendon-derived stem cells contribute to the pathogenesis of calcifying tendinopathy?
Yun-feng RUI ; Pauline Po-yee LUI ; Lai-shan CHAN ; Kai-ming CHAN ; Sai-chuen FU ; Gang LI
Chinese Medical Journal 2011;124(4):606-610
Calcifying tendinopathy is a tendon disorder with calcium deposits in the mid-substance presented with chronic activity-related pain, tenderness, local edema and various degrees of incapacitation. Most of current treatments are neither effective nor evidence-based because its underlying pathogenesis is poorly understood and treatment is usually symptomatic. Understanding the pathogenesis of calcifying tendinopathy is essential for its effective evidence-based management. One of the key histopathological features of calcifying tendinopathy is the presence of chondrocyte phenotype which surrounds the calcific deposits, suggesting that the formation of calcific deposits was cell-mediated. Although the origin of cells participating in the formation of chondrocyte phenotype and ossification is still unknown, many evidences have suggested that erroneous tendon cell differentiation is involved in the process. Recent studies have shown the presence of stem cells with self-renewal and multi-differentiation potential in human, horse, mouse and rat tendon tissues. We hypothesized that the erroneous differentiation of tendon-derived stem cells (TDSCs) to chondrocytes or osteoblasts leads to chondrometaplasia and ossification and hence weaker tendon, failed healing and pain, in calcifying tendinopathy. We present a hypothetical model on the pathogenesis and evidences to support this hypothesis. Understanding the key role of TDSCs in the pathogenesis of calcifying tendinopathy and the mechanisms contributing to their erroneous differentiation would provide new opportunities for the management of calcifying tendinopathy. The re-direction of the differentiation of resident TDSCs to tenogenic or supplementation of MSCs programmed for tenogenic differentiation may be enticing targets for the management of calcifying tendinopathy in the future.
Animals
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Cell Differentiation
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physiology
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Humans
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Mice
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Rats
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Stem Cells
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pathology
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Tendinopathy
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etiology
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pathology
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Tendons
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pathology
2.A Fatal Case of Naegleria fowleri Meningoencephalitis in Taiwan.
Mei Yu SU ; Ming Shih LEE ; Ling Yuh SHYU ; Wei Chen LIN ; Pei Ching HSIAO ; Chi Ping WANG ; Dar Der JI ; Ke Min CHEN ; Shih Chan LAI
The Korean Journal of Parasitology 2013;51(2):203-206
After bathing at a hot spring resort, a 75-year-old man presented to the emergency department because of seizure-like attack with loss of conscious. This is the first case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in Taiwan. PAM was diagnosed based on detection of actively motile trophozoites in cerebrospinal fluid using a wet-mount smear and the Liu's stain. The amoebae were further confirmed by PCR and gene sequencing. In spite of administering amphotericin B treatment, the patient died 25 days later.
Aged
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Amebiasis/*diagnosis/parasitology/*pathology
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Central Nervous System Protozoal Infections/*diagnosis/parasitology/*pathology
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Cerebrospinal Fluid/parasitology
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DNA, Protozoan/chemistry/genetics
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Fatal Outcome
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Humans
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Male
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Microscopy
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Naegleria fowleri/classification/genetics/*isolation & purification
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Polymerase Chain Reaction
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Sequence Analysis, DNA
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Taiwan
3.Echocardiographic mapping of left ventricular resynchronization during cardiac resynchronization therapy procedures.
Ngai-Yin CHAN ; Chi-Chung CHOY ; Kar-Chun CHEUNG ; Chun-Leung LAU ; Ying-Keung LO ; Pui-Shan CHU ; Ho-Chuen YUEN ; Suet-Ting LAU ; Yuen-Choi CHOI
Chinese Medical Journal 2010;123(13):1645-1651
BACKGROUNDCardiac resynchronization therapy (CRT) is an effective electrical therapy for patients with moderate to severe heart failure and cardiac dyssynchrony. This study aimed to investigate the degree of acute left ventricular (LV) resynchronization with biventricular pacing (BVP) at different LV sites and to examine the feasibility of performing transthoracic echocardiography (TTE) to quantify acute LV resynchronization during CRT procedure.
METHODSFourteen patients with NYHA Class III-IV heart failure, LV ejection fraction < or = 35%, QRS duration > or = 120 ms and septal-lateral delay (SLD) > or = 60 ms on tissue Doppler imaging (TDI), underwent CRT implant. TDI was obtained from three apical views during BVP at each accessible LV site and SLD during BVP was derived. Synchronicity gain index (Sg) by SLD was defined as (1 + (SLD at baseline--SLD at BVP)/SLD at baseline).
RESULTSSeventy-two sites were studied. Positive resynchronization (R+, Sg > 1) was found in 42 (58%) sites. R+ was more likely in posterior or lateral than anterior LV sites (66% vs. 36%, P < 0.001). Concordance of empirical LV lead implantation sites and sites with R+ was 50% (7/14).
CONCLUSIONSThe degree of acute LV resynchronization by BVP depends on LV lead location and empirical implantation of LV lead results in only 50% concordance with R+. Performing TTE during CRT implantation is feasible to identify LV sites with positive resynchronization.
Aged ; Cardiac Resynchronization Therapy ; methods ; Echocardiography ; methods ; Female ; Heart Failure ; therapy ; Humans ; Male ; Middle Aged ; Ventricular Dysfunction, Left ; therapy
4.SingHealth Radiology Archives pictorial essay Part 1: cardiovascular, respiratory and neurological cases.
Mark Bangwei TAN ; Kim Ping TAN ; Joey Chan Yiing BEH ; Eugenie Yi Kar CHAN ; Kenneth Fu Wen CHIN ; Zong Yi CHIN ; Wei Ming CHUA ; Aaron Wei-Loong CHONG ; Gary Tianyu GU ; Wenlu HOU ; Anna Chooi Yan LAI ; Rebekah Zhuyi LEE ; Perry Jia Ren LIEW ; May Yi Shan LIM ; Joshua Li Liang LIM ; Zehao TAN ; Eelin TAN ; Grace Siew Lim TAN ; Timothy Shao Ern TAN ; Eu Jin TAN ; Alexander Sheng Ming TAN ; Yet Yen YAN ; Winston Eng Hoe LIM
Singapore medical journal 2020;61(12):633-640
The Singapore Health Services cluster (SingHealth) radiology film archives are a valuable repository of local radiological cases dating back to the 1950s. Some of the cases in the archives are of historical medical interest, i.e. cerebral angiography in the workup of patients with hemiplegia. Other cases are of historical social interest, being conditions seen during earlier stages of Singapore's development, i.e. bound feet. The archives form a unique portal into the development of local radiology as well as the national development of Singapore. A selection from the archives is published in 2020 in commemoration of the 20th anniversary of the formation of SingHealth, the 55th National Day of Singapore, and the 125th anniversary of the International Day of Radiology. This pictorial essay comprises cardiovascular, respiratory and neurological cases from the archives.
5.SingHealth Radiology Archives pictorial essay Part 2: gastroenterology, musculoskeletal, and obstetrics and gynaecology cases.
Mark Bangwei TAN ; Kim Ping TAN ; Joey Chan Yiing BEH ; Eugenie Yi Kar CHAN ; Kenneth Fu Wen CHIN ; Zong Yi CHIN ; Wei Ming CHUA ; Aaron Wei-Loong CHONG ; Gary Tianyu GU ; Wenlu HOU ; Anna Chooi Yan LAI ; Rebekah Zhuyi LEE ; Perry Jia Ren LIEW ; May Yi Shan LIM ; Joshua Li Liang LIM ; Zehao TAN ; Eelin TAN ; Grace Siew Lim TAN ; Timothy Shao Ern TAN ; Eu Jin TAN ; Alexander Sheng Ming TAN ; Yet Yen YAN ; Winston Eng Hoe LIM
Singapore medical journal 2021;62(1):8-15
The Singapore Health Services cluster (SingHealth) radiology film archives are a valuable repository of local radiological cases dating back to the 1950s. Some of the cases in the archives are of historical medical interest, i.e. cerebral angiography in the workup of patients with hemiplegia. Other cases are of historical social interest, being conditions seen during earlier stages of Singapore's development, i.e. bound feet. The archives form a unique portal into the development of local radiology as well as the national development of Singapore. A selection from the archives is published in commemoration of the International Day of Radiology in 2020, as well as the 200th anniversary of the Singapore General Hospital in 2021. This pictorial essay comprises gastroenterology, musculoskeletal and obstetrics and gynaecology cases from the archives.