1.Clinical experience with the cordis coronary stent in the Chinese population
Fan K. ; Chow W.H. ; Chow L. ; Yip A. ; Cheung K.L.
Chinese Medical Journal 1998;111(4):0-0
Objective To assess the safety and efficacy of the new Cordis coronary stent in the Chinese population.Patients A total of 32 patients recieved 34 Cordis stents (target lesions of 32) from July to December 1995 in our hospital. Vessel distribution was 18 LAD (53%), 8 Lcx (23.5%) and 8 RCA (23.5%).Methods All cases were studies retrospectively. The coronary lesions were predilated with standard balloon angioplasty followed by implantation of Cordis stents. The reference diameter of the vessels and the minimal luminal diameters (both before and after stent implantation) were measured by quantitative angiography. All patients were followed up at mean peroid of 3 months with regards to their symptoms and angiographic follow-up at 6 month's time were carried out in 8 patients.Results Delivery success was achieved in all lesions except 1 unsuccessful delivery due to failure to negotiate an acute angle of a left main vessel to LAD. Average MLD post stenting was satisfactory (0.53±0.36 mm vs 3.32±0.34 mm) compared to reference diameter of 3.13±0.4 mm. There was 1 patient with complication of subacute stent thrombosis. Another patient died 5 weeks later from non-ischaemic end stage heart failure secondary to severe aortic regurgitation. Loop seperations occurred in 2 stents (5.8%) during deployment.Conclusions The Cordis stent implantation is efficacious with high angiographic success rate. The strong radiopacity facilitates precise positioning of the stent in the target lesions. Our experience in the Chinese population is favourable. Stent deformity was possible. For smaller stents of 3 mm, higher pressure of balloon inflation for deployment followed by adequate anticoagulation is recommended. Further studies are required to investigate the long term restenosis rate.
2.Use of healthcare worker sickness absenteeism surveillance as a potential early warning system for influenza epidemics in acute care hospitals.
Sapna SADARANGANI ; Mark I C CHEN ; Angela L P CHOW ; Arul EARNEST ; Mar Kyaw WIN ; Brenda S P ANG
Annals of the Academy of Medicine, Singapore 2010;39(4):341-342
3.Angioplasty on an infarct-related anomalous right coronary artery arising from posterior coronary sinus.
Man-Hong JIM ; Ryan L Y KO ; Carmen W S CHAN ; Stephen C W CHEUNG ; Wing-Hing CHOW
Annals of the Academy of Medicine, Singapore 2010;39(3):258-260
INTRODUCTIONThe objective of this case report was to illustrate the diagnostic and intervention approach of anomalous right coronary artery (RCA).
CLINICAL PICTUREA 60-year-old man presented with acute inferior myocardial infarction. Cardiac catheterisation revealed an anomalous RCA arising from the posterior coronary sinus as the infarct-related artery.
TREATMENTAd hoc percutaneous coronary intervention with stent implantation was performed using a few technical modifications.
OUTCOMEGood angiographic result was achieved within 90 minutes, with 260 mL of contrast used.
CONCLUSIONA high index of suspicion and logical diagnostic and intervention approach are required for the proper management of anomalous RCA.
Angioplasty, Balloon, Coronary ; Cardiac Catheterization ; methods ; Coronary Angiography ; Coronary Vessel Anomalies ; complications ; diagnostic imaging ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; complications ; surgery
4.Immunomodulatory Effects of Adipose Tissue-Derived Stem Cells on Elastin Scaffold Remodeling in Diabetes.
James P CHOW ; Dan T SIMIONESCU ; Anna L CARTER ; Agneta SIMIONESCU
Tissue Engineering and Regenerative Medicine 2016;13(6):701-712
Diabetes is a major risk factor for the progression of vascular disease, contributing to elevated levels of glycoxidation, chronic inflammation and calcification. Tissue engineering emerges as a potential solution for the treatment of vascular diseases however there is a considerable gap in the understanding of how scaffolds and stem cells will perform in patients with diabetes. We hypothesized that adipose tissue-derived stem cells (ASCs) by virtue of their immunosuppressive potential would moderate the diabetes-intensified inflammatory reactions and induce positive construct remodeling. To test this hypothesis, we prepared arterial elastin scaffolds seeded with autologous ASCs and implanted them subdermally in diabetic rats and compared inflammatory markers, macrophage polarization, matrix remodeling, calcification and bone protein expression to control scaffolds implanted with and without cells in nondiabetic rats. ASC-seeded scaffolds exhibited lower levels of CD8+ T-cells and CD68+ pan-macrophages and higher numbers of M2 macrophages, smooth muscle cell-like and fibroblast-like cells. Calcification and osteogenic markers were reduced in ASCseeded scaffolds implanted in non-diabetic rats but remained unchanged in diabetes, unless the scaffolds were first pre-treated with penta-galloyl glucose (PGG), a known anti-oxidative elastin-binding polyphenol. In conclusion, autologous ASC seeding in elastin scaffolds is effective in combating diabetes-related complications. To prevent calcification, the oxidative milieu needs to be reduced by elastin-binding antioxidants such as PGG.
Animals
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Antioxidants
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Diabetes Complications
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Elastin*
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Glucose
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Humans
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Inflammation
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Macrophages
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Muscle, Smooth
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Prostaglandins G
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Rats
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Risk Factors
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Stem Cells*
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T-Lymphocytes
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Tissue Engineering
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Vascular Diseases
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Virtues
5.Atypical enhancement pattern of hepatocellular carcinoma with portal vein thrombosis on multiphasic CT.
Yee Liang THIAN ; Albert S C LOW ; Pierce K H CHOW ; London L OOI ; Alexander Y F CHUNG ; Shoen C S LOW ; Wanying XIE ; Choon Hua THNG
Annals of the Academy of Medicine, Singapore 2011;40(10):454-459
INTRODUCTIONThe 2005 American Association for Study of Liver Diseases (AASLD) diagnostic criteria allow non-invasive diagnosis of hepatocellular carcinoma (HCC) based on their enhancement pattern but we have observed a high incidence of atypical enhancement characteristics in HCC associated with portal vein thrombosis. This study seeks to examine the radiological features of this particular subgroup.
MATERIALS AND METHODSPatients with HCC and portal vein thrombosis who underwent pre-treatment multiphasic CT imaging were drawn from a surgical database. The arterial, portal venous and delayed phase images were assessed qualitatively and quantitatively (with region of interest [ROI] analysis) for lesion hypervascularity and washout. The background enhancement of the left and right lobes of the liver was also quantifi ed by ROI analysis.
RESULTSTwenty-fi ve lesions in 25 patients were selected for analysis. Qualitative analysis showed that 10/25 (40%) lesions demonstrated arterial hypervascularity while 16/25 (64%) lesions showed washout. Ten out of 25 (40%) lesions demonstrated both arterial hypervascularity and washout. Quantitative analysis showed that the average absolute lesion enhancement from precontrast to arterial phases was 49.1 (± 17.1) HU for hypervascular lesions compared to 23.8 (± 16.6) HU for non-hypervascular lesions (P <0.01). The mean absolute enhancement of the background liver parenchyma in the arterial phase was 13.79 (± 7.9) HU for hypervascular lesions compared to 36.6 (± 30.6) HU for non-hypervascular lesions (P = 0.03).
CONCLUSIONA large proportion of HCC with portal vein thrombosis lack characteristic arterial hypervascularity, which may be secondary to compensatory increased arterial supply to the background liver. This is a potential pitfall when applying imaging criteria for diagnosis of HCC.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular ; complications ; diagnostic imaging ; Female ; Humans ; Liver Neoplasms ; complications ; diagnostic imaging ; Male ; Middle Aged ; Pattern Recognition, Automated ; Portal Vein ; diagnostic imaging ; physiopathology ; Retrospective Studies ; Tomography, X-Ray Computed ; methods ; Venous Thrombosis ; diagnostic imaging ; etiology
6.Accuracy of diabetic retinopathy screening by trained non-physician graders using non-mydriatic fundus camera.
Mayuri BHARGAVA ; Carol Yim-Lui CHEUNG ; Charumathi SABANAYAGAM ; Ryo KAWASAKI ; C Alex HARPER ; Ecosse L LAMOUREUX ; Wai Leng CHOW ; Adrian EE ; Haslina HAMZAH ; Maisie HO ; Wanling WONG ; Tien Yin WONG
Singapore medical journal 2012;53(11):715-719
INTRODUCTIONWe compared the agreement of diabetic retinopathy (DR) assessment between trained non-physician graders (NPGs) and family physicians (FPs) in a primary healthcare setting.
METHODSThis was a cross-sectional study conducted retrospectively over a period of one month. The participants were diabetic patients from two primary healthcare clinics (polyclinics) in Singapore. Single-field digital retinal images were obtained using a non-mydriatic 45-degree fundus camera. Retinal images were graded for the presence or absence of DR by FPs at the polyclinics and by NPGs at a central ocular grading centre. The FPs' and NPGs' assessments of DR were compared with readings by a single retinal specialist (reference standard).
RESULTSA total of 367 diabetic patients (706 eyes) were included in the study. The mean age of the patients was 63 years, and the majority were Chinese (83.8%). For DR assessment, the agreement between NPGs and the retinal specialist was substantial (ĸ = 0.66), while the agreement between FPs and the retinal specialist was only fair (ĸ = 0.40). NPGs' assessment showed higher sensitivity (70% vs. 45%) and comparable specificity (94% vs. 92%) as compared to FPs' assessment. The area under the receiver operating characteristic curve of NPGs' assessment of DR was greater than that of the FPs' (0.82 vs. 0.69, p < 0.001).
CONCLUSIONThis study has demonstrated that trained NPGs are able to provide good detection of DR and maculopathy from fundus photographs. Our findings suggest that DR screening by trained NPGs may provide a costeffective alternative to FPs.
Aged ; Cross-Sectional Studies ; Diabetic Retinopathy ; diagnosis ; Female ; Humans ; Male ; Middle Aged ; Mydriatics ; Nurses ; Observer Variation ; Ophthalmology ; manpower ; Physicians, Family ; Primary Health Care ; methods ; ROC Curve ; Referral and Consultation ; Reproducibility of Results ; Sensitivity and Specificity ; Singapore
7.Evolution of Diabetes Care in Hong Kong: From the Hong Kong Diabetes Register to JADE-PEARL Program to RAMP and PEP Program.
Ivy H Y NG ; Kitty K T CHEUNG ; Tiffany T L YAU ; Elaine CHOW ; Risa OZAKI ; Juliana C N CHAN
Endocrinology and Metabolism 2018;33(1):17-32
The rapid increase in diabetes prevalence globally has contributed to large increases in health care expenditure on diabetic complications, posing a major health burden to countries worldwide. Asians are commonly observed to have poorer β-cell function and greater insulin resistance compared to the Caucasian population, which is attributed by their lower lean body mass and central obesity. This “double phenotype” as well as the rising prevalence of young onset diabetes in Asia has placed Asians with diabetes at high risk of cardiovascular and renal complications, with cancer emerging as an important cause of morbidity and mortality. The experience from Hong Kong had demonstrated that a multifaceted approach, involving team-based integrated care, information technological advances, and patient empowerment programs were able to reduce the incidence of diabetic complications, hospitalizations, and mortality. System change and public policies to enhance implementation of such programs may provide solutions to combat the burgeoning health problem of diabetes at a societal level.
Architectural Accessibility*
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Asia
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Asian Continental Ancestry Group
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Delivery of Health Care
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Diabetes Complications
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Diabetes Mellitus, Type 2
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Health Expenditures
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Hong Kong*
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Hospitalization
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Humans
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Incidence
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Insulin Resistance
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Mortality
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Obesity, Abdominal
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Patient Participation
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Prevalence
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Public Policy
8.Wash-out of hepatocellular carcinoma: quantitative region of interest analysis on CT.
Cher Heng TAN ; Choon Hua THNG ; Albert S C LOW ; Veronique K M TAN ; Septian HARTONO ; Tong San KOH ; Brian K P GOH ; Peng Chung CHEOW ; Yu Meng TAN ; Alexander Y F CHUNG ; London L OOI ; Arul EARNEST ; Pierce K H CHOW
Annals of the Academy of Medicine, Singapore 2011;40(6):269-275
INTRODUCTIONThis study aims to determine if the quantitative method of region-of-interest (ROI) analysis of lesion attenuation on CT may be a useful adjunct to the conventional approach of diagnosis by visual assessment in assessing tracer wash-out in hepatocellular carcinomas.
MATERIALS AND METHODSFrom a surgical database of 289 patients from 2 institutions, all patients with complete surgical, pathological and preoperative multiphasic CT scans available for review were selected. For each phase of scanning, HU readings of lesion obtained (Lesion(arterial), Lesion(PV) and Lesion(equilibrium)) were analysed using receiver operating curves (ROC) to determine the optimal method and cut-off value for quantitative assessment of tumour wash-out (Lesion(arterial - equilibrium), Lesion(PV - equilibrium) or Lesion(peak - equilibrium)).
RESULTSNinety-four patients with one lesion each met the inclusion criteria. The area under the curve (AUC) values for Lesion(arterial - equilibrium) (0.941) was higher than the AUC for Lesion(pv - equilibrium) (0.484) and for Lesion(peak - equilibrium) (0.667). Based on ROC analysis, a cut-off of 10HU value for Lesion(arterial - equilibrium) would yield sensitivity and specificity of 91.5% and 80.9%, respectively. ROI analysis detected 9/21 (42.9%) of lesions missed by visual analysis. Combined ROI and visual analysis yields a sensitivity of 82/94 (87.2%) compared to 73/94 (77.7%) for visual analysis alone.
CONCLUSIONUsing a cut-off of 10 HU attenuation difference between the arterial and equilibrium phases is a simple and objective method that can be included as an adjunct to visual assessment to improve sensitivity for determining lesion wash-out on CT.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular ; diagnosis ; pathology ; surgery ; Confidence Intervals ; Databases, Factual ; Female ; Humans ; Liver ; pathology ; Liver Neoplasms ; diagnosis ; pathology ; surgery ; Male ; Middle Aged ; Preoperative Period ; ROC Curve ; Retrospective Studies ; Sensitivity and Specificity ; Tomography, X-Ray Computed ; instrumentation ; Young Adult