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Lee WC, Man SS, Lau KW, Cheng LC, Kwong NS, Kwong KL. Uses and abuses of paediatric electroencephalography. Hong Kong Med J 2012; 18:25-29. [PMID: 22302907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVE To investigate whether requests for standard paediatric electroencephalograms accord with guideline recommendations, subsequent changes in clinical management according to reported results, and extent to which the service meets waiting time targets. DESIGN Case series. SETTING Regional hospital, Hong Kong. PATIENTS All patients aged less than 18 years who underwent electroencephalography between December 2009 and February 2010. MAIN OUTCOME MEASURES Appropriateness of the electroencephalogram request and the impact of its findings on clinical management. RESULTS A total of 109 patients were recruited, but requests for standard electroencephalograms were considered 'inappropriate' with respect to guidelines in 44% of the patients, of which 50% were made to diagnose 'funny turns'. The standard electroencephalogram contributed to the diagnosis or management in only 28% of patients. In all of the latter, the request for an electroencephalogram had been appropriate. Nonspecialists made referrals for 86% of the patients. Inadequate information was provided in 66% of the requests. Standard electroencephalograms were performed within guideline targets, the wait being less than 4 weeks in 95% of requests. CONCLUSION An effective electroencephalogram service was being provided, though abuses were common. These were mainly because of misconceptions regarding the role and limitations of standard electroencephalograms. Through an educative, non-confrontational approach, and with time to explain guideline recommendations to clinicians, sustainable change in practice could be achieved so as to benefit patients, clinicians, and service provision.
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Chen CD, Lee HL, Chan CK, Ang CL, Azahari AH, Lau KW, Sofian-Azirun M. Laboratory bioefficacy of nine commercial formulations of temephos against larvae of Aedes aegypti (L.), Aedes albopictus Skuse and Culex quinquefasciatus Say. Trop Biomed 2009; 26:360-365. [PMID: 20237452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The bioefficacy of nine commercial formulations of temephos against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae were evaluated in the laboratory. WHO larval bioassay with operational dosage of temephos at 1 mg/L was performed. The larval mortality was recorded every 5 minutes until complete mortality was achieved. All formulations of temephos exhibited various toxicity level against Ae. aegypti, Ae. albopictus and Cx. quinquefasciatus. Generally, larvae of Cx. quinquefasciatus was susceptible to all formulations of temephos, followed by Ae. aegypti and Ae. albopictus.
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Thompson RF, Suzuki M, Lau KW, Greally JM. A pipeline for the quantitative analysis of CG dinucleotide methylation using mass spectrometry. ACTA ACUST UNITED AC 2009; 25:2164-70. [PMID: 19561019 DOI: 10.1093/bioinformatics/btp382] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
MOTIVATION DNA cytosine methylation is an important epigenetic regulator, critical for mammalian development and the control of gene expression. Numerous techniques using either restriction enzyme or affinity-based approaches have been developed to interrogate cytosine methylation status genome-wide, however these assays must be validated by a more quantitative approach, such as MALDI-TOF mass spectrometry of bisulphite-converted DNA (commercialized as Sequenom's EpiTYPER assay using the MassArray system). Here, we present an R package ('MassArray') that assists in assay design and uses the standard Sequenom output file as the input to a pipeline of analyses not available as part of the commercial software. The tools in this package include bisulphite conversion efficiency calculation, sequence polymorphism flagging and visualization tools that combine multiple experimental replicates and create tracks for genome browser viewing.
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Chen CD, Lee HL, Nazni WA, Seleena B, Lau KW, Daliza AR, Ella Syafinas S, Mohd Sofian A. Field effectiveness of Bacillus thuringiensis israelensis (Bti) against Aedes (Stegomyia) aegypti (Linnaeus) in ornamental ceramic containers with common aquatic plants. Trop Biomed 2009; 26:100-105. [PMID: 19696734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study was undertaken to determine the impact of larvaciding using a Bti (Bacillus thuringiensis israelensis) formulation (VectoBac WG) against Aedes aegypti larvae in earthen jars containing aquatic plants. Aquatic plants commonly used for landscaping, Pistia stratiotes (L.) (Liliopsida: Araceae) and Sagittaria sp. (Liliopsida: Alismataceae) were placed inside earthen jars filled with 50 L tap water. All earthen jars were treated with Bti formulation at 8g/1000L. Untreated jars with and without aquatic plants were also set up as controls. Fifty laboratory-bred 2nd instar larvae were introduced into each earthen jar. All earthen jars were observed daily. Number of adults emerged was recorded and the larval mortality was calculated. The indicators of effectiveness of Bti for these studies were (i) residual activities of Bti, and (ii) larval mortality in earthen jars with or without aquatic plants. The treated earthen jars containing P. stratiotes and Sagittaria sp. showed significant residual larvicidal effect up to 7 weeks, in comparison to untreated control (p < 0.05). The larval mortality ranged from 77.34% - 100% for jars with aquatic plants vs 80.66% - 100% for jars without aquatic plant. Earthen jars treated with Bti without aquatic plants also exhibited significantly longer residual larvicidal activity of up to 10 weeks (p < 0.05). The larval mortality ranged from 12.66% - 100% for jars with aquatic plants vs 59.34% - 100% for jars without aquatic plant. Thus, earthen jars without aquatic plants exhibited longer residual larvicidal effect compared to those with aquatic plants. This study suggested that containers with aquatic plants for landscaping should be treated more frequently with Bti in view of the shortened residual activity.
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Lau KW, Ding ZP, Hung JS. Percutaneous transvenous mitral commissurotomy versus surgical commissurotomy in the treatment of mitral stenosis. Clin Cardiol 2009; 20:99-106. [PMID: 9034637 PMCID: PMC6656037 DOI: 10.1002/clc.4960200204] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
There is no doubt that percutaneous transvenous mitral commissurotomy (PTMC) in experienced centers is associated with a low risk of major complications and yields excellent immediate and long-term outcome. Although previous observational studies on both PTMC and surgical commissurotomy have indicated similar outcome between the two treatment strategies in terms of valve area improvement and risk of major complication (death, thromboembolism and significant resultant mitral regurgitation), it was not until recently that several prospective randomized trials comparing the two procedures and involving > 470 patients with favorable valve characteristics (pliable, noncalcified valve with mild subvalvular disease and no or mild mitral regurgitation), have confirmed that PTMC is indeed just as, if not more, effective as surgical commissurotomy. The late restenosis rate at up to 3-year follow-up appears comparable. Furthermore, PTMC has other additional benefits. It is nontraumatic, may be repeated without additional risk, and has been shown to be an extremely useful and efficacious palliative tool in those with end-stage mitral stenosis or with unfavorable valve anatomy who refuse surgery, and in certain subset of patients at high surgical risk because of medical comorbidities.
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Lau KW, He Q, Ding ZP, Johan A. Safety and efficacy of angiography-guided stent placement in small native coronary arteries of < 3.0 mm in diameter. Clin Cardiol 2009; 20:711-6. [PMID: 9259164 PMCID: PMC6655322 DOI: 10.1002/clc.4960200809] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND AND HYPOTHESIS Increased operator experience, greater insight in stent deployment techniques, and improved poststent medication regimen have significantly reduced the risk of thrombotic stent closure following stent placement in large coronary arteries (> or = 3.0 mm in diameter). Whether equally favorable results are afforded by stent placement in small vessels (< 3.0 mm), however, remains unclear. Accordingly, the aim of this study was the specific examination of the risk of stent placement in small native coronary vessels, using stent deployment technique consisting of supplementary dilatations with larger balloons or high-pressure inflations, and aggressive aspirin-ticlopidine and short-term oral anticoagulation poststent therapy. METHODS Forty-seven balloon-expandable stents (20 Gianturco-Roubin, 21 NIR, 6 Palmaz-Schatz) were successfully implanted without intravascular guidance in 45 native coronary arteries (mean reference diameter of 2.5 mm) in 44 consecutive patients (31 men, 13 men), the majority of whom (87%) were stented for the treatment of failed or suboptimal balloon angioplasty outcome. RESULTS Successful stent placement reduced the lesion diameter stenosis from 91 +/- 9% to 3 +/- 7% (p = 0.0001). There were no early stent thrombosis or major cardiovascular events prior to hospital discharge. During a 12-month follow-up period, most patients remained symptomatically improved and no myocardial infarction, stroke, or death was observed. Five-month angiographic reassessment revealed an in-stent restenosis rate of 41%, which was higher in vessels < or = 2.5 mm in size (47 vs. 33% for vessels > 2.5 mm, p = 0.2747). CONCLUSIONS In selected patients with small native coronary vessels < 3.0 mm in diameter, angiography-guided optimal stent placement is associated with a low risk of stent thrombosis and bleeding complications. However, the in-stent restenosis rate is high with the stents used in this study.
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Lau KW, Tian YM, Raval RR, Ratcliffe PJ, Pugh CW. Target gene selectivity of hypoxia-inducible factor-alpha in renal cancer cells is conveyed by post-DNA-binding mechanisms. Br J Cancer 2007; 96:1284-92. [PMID: 17387348 PMCID: PMC2360163 DOI: 10.1038/sj.bjc.6603675] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inactivation of the von Hippel–Lindau tumour suppressor in renal cell carcinoma (RCC) leads to failure of proteolytic regulation of the α subunits of hypoxia-inducible factor (HIF), constitutive upregulation of the HIF complex, and overexpression of HIF target genes. However, recent studies have indicated that in this setting, upregulation of the closely related HIF-α isoforms, HIF-1α and HIF-2α, have contrasting effects on tumour growth, and activate distinct sets of target genes. To pursue these findings, we sought to elucidate the mechanisms underlying target gene selectivity for HIF-1α and HIF-2α. Using chromatin immunoprecipitation to probe binding to hypoxia response elements in vivo, and expression of chimaeric molecules bearing reciprocal domain exchanges between HIF-1α and HIF-2α molecules, we show that selective activation of HIF-α target gene expression is not dependent on selective DNA-binding at the target locus, but depends on non-equivalent C-terminal portions of these molecules. Our data indicate that post-DNA binding mechanisms that are dissimilar for HIF-1α and HIF-2α determine target gene selectivity in RCC cells.
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Wong ML, Chia KS, Yam WM, Teodoro GR, Lau KW. Willingness to donate blood samples for genetic research: a survey from a community in Singapore. Clin Genet 2004; 65:45-51. [PMID: 15032974 DOI: 10.1111/j..2004.00192.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Studies on the public's willingness to donate blood specimens for genetic research are few and are conducted mainly among Western countries. Little is known about the Asian community's willingness to participate in genetic research. A community-based survey was conducted on 548 adult Singaporeans to examine their willingness to donate blood samples for genetic research and its associated factors. The response rate was 70.3%. About 49.3% (95% CI, 45.1-53.5%) were willing to donate blood for genetic research. In the multivariable Cox regression analysis, willingness was significantly associated with belief in the benefits of genetic research; intention to participate in government studies; having no fear of pain, blood, injections, and needles; and non-concern about the loss of confidentiality. Reasons against donating blood were fear of pain, blood, injections, and needles (38.1%); no self-benefits (24.8%); fear of finding out about having a disease (22.3%); fear of discrimination (18.7%); and concerns about weakness (15.1%) and weight gain (9.4%). Public education programs to promote participation in genetic research should stress its benefits and address people's fears and concerns.
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Lau KW, Johan A, Sigwart U, Hung JS. A stent is not just a stent: Stent construction and design do matter in its clinical performance. Singapore Med J 2004; 45:305-11; quiz 312. [PMID: 15221045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
The undisputed superiority of stents over conventional balloon angioplasty has resulted in a plethora of stents in clinical use. Recent data, however, have indicated not all stent models are the same. Nuances in stent design and construction have impacted significantly on the immediate and long-term clinical outcome. Among the stainless steel stents, those with multicellular or tubular designs have proven to be superior to coiled or hybrid stent models, and thin-strut stents perform better than thicker-strut stents. Coating stainless steel stents with gold, carbide, phosphorylcholine or heparin do not appear to confer any additional benefit, compared with bare metal stents. In contrast, randomised trials have demonstrated that drug-eluting stents coated with various anti-proliferative drugs, with or without a carrier polymer, afford unparalleled restenosis rates compared with non-drug-eluting stents. Drug-eluting stents, however, are expensive, and their long-term durability and safety remain undefined. Notwithstanding these unresolved issues, it is likely that the majority of percutaneous coronary interventions will involve the use of drug-eluting stents once a more attractive balance between their cost and clinical effects is reached.
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Hsu LF, Mak KH, Lau KW, Sim LL, Chan C, Koh TH, Chuah SC, Kam R, Ding ZP, Teo WS, Lim YL. Clinical outcomes of patients with diabetes mellitus and acute myocardial infarction treated with primary angioplasty or fibrinolysis. Heart 2002; 88:260-5. [PMID: 12181218 PMCID: PMC1767339 DOI: 10.1136/heart.88.3.260] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To compare the early and late outcomes of primary percutaneous transluminal coronary angioplasty (PTCA) with fibrinolytic treatment among diabetic patients with acute myocardial infarction (AMI). DESIGN Retrospective observational study with data obtained from prospective registries. SETTING Tertiary cardiovascular institution with 24 hour acute interventional facilities. PATIENTS 202 consecutive diabetic patients with AMI receiving reperfusion treatment within six hours of symptom onset. INTERVENTIONS Fibrinolytic treatment was administered to 99 patients, and 103 patients underwent primary PTCA. Most patients undergoing PTCA received adjunctive stenting (94.2%) and glycoprotein IIb/IIIa inhibition (63.1%). MAIN OUTCOME MEASURES Death, non-fatal reinfarction, and target vessel revascularisation at 30 days and one year were assessed. RESULTS Baseline characteristics were similar in these two treatment groups except that the proportion of patients with Killip class III or IV was considerably higher in those treated with PTCA (15.5% v 6.1%, p = 0.03) and time to treatment was significantly longer (103.7 v 68.0 minutes, p < 0.001). Among those treated with PTCA, the rates for in-hospital recurrent ischaemia (5.8% v 17.2%, p = 0.011) and target vessel revascularisation at one year (19.4% v 36.4%, p = 0.007) were lower. Death or reinfarction at one year was also reduced among those treated with PTCA (17.5% v 31.3%, p = 0.02), with an adjusted relative risk of 0.29 (95% confidence interval 0.15 to 0.57) compared with fibrinolysis. CONCLUSION Among diabetic patients with AMI, primary PTCA was associated with reduced early and late adverse events compared with fibrinolytic treatment.
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Tay MH, Lau KW, Ding ZP, Lee CN. An interesting case of left atrial myxoma. Singapore Med J 2002; 43:367-8. [PMID: 12437046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Myxoma is the most common type of primary tumours of the heart in adults. Majority of these myxomas are found in the left atrium, followed by the right atrium and ventricles. We describe herein a patient who had a left atrial myxoma with interesting investigational results.
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Naik MJ, Chua YL, Ding ZP, Lau KW. Coronary artery bypass grafts in situs inversus. THE JOURNAL OF CARDIOVASCULAR SURGERY 2002; 43:181-4. [PMID: 11887051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Coronary artery bypass grafting in dextrocardia is rare. A case is described for the first time where both arterial and venous conduits were used. The subtle changes required in the conduct of the operation are highlighted.
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Ko JM, Wong CP, Tang CM, Lau KW, Lung ML. Frequent loss of heterozygosity on multiple chromosomes in Chinese esophageal squamous cell carcinomas. Cancer Lett 2001; 170:131-8. [PMID: 11463490 DOI: 10.1016/s0304-3835(01)00577-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Analysis of the loss of heterozygosity (LOH) detected by polymerase chain reaction techniques using 18 polymorphic markers localized to chromosomes 3p, 5, 17, and 18q in 40 Hong Kong Chinese esophageal squamous cell carcinoma (ESC) patients showed that multiple alterations on several chromosomes are involved in ESC development. The LOH rates detected for markers on chromosome 3 ranged from 44.0 to 85.7%, for chromosome 5 from 40.9 to 61.9%, for chromosome 17 from 40.0 to 100%, and for chromosome 18 from 38.9 to 58.3%. No significant association was observed between LOH and the clinical and histopathological parameters.
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Murray SL, Lau KW, Begg A, Jacobs K. Myelodysplasia, hypophosphataemia, vitamin D and iron deficiency in an alpaca. Aust Vet J 2001; 79:328-31. [PMID: 11431996 DOI: 10.1111/j.1751-0813.2001.tb12005.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A pregnant 2-year-old alpaca was presented for evaluation of progressive weight loss, decreased appetite and lethargy that developed in winter. Haematologic and serum biochemical analyses revealed marked anaemia, leukopenia, severe hypophosphataemia and mild hypocalcaemia. Evaluation of bone marrow core biopsies and aspirates revealed an increased proportion of immature haematopoietic cells, without sufficient numbers of blast cells to be termed an acute myeloid leukaemia (AML). 1 The haematological and bone marrow findings were suggestive of myelodysplastic syndrome (MDS). The anaemia, leukopenia, lethargy and weight loss remained refractory to medical therapy and the alpaca was euthanased on humane grounds.
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Naik M, Lau KW, Chua YL. Guidewire perforation during PTCA with subsequent off-pump bypass surgery. Tex Heart Inst J 2001; 28:70-1. [PMID: 11330749 PMCID: PMC101138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Abstract
Stenting lesions with favorable characteristics as required for inclusion in the STRESS/BENESTENT trials have yielded superior results to that of PTCA alone. Results for less favorable lesions such as in small vessels, diffuse disease, ostial disease, and saphenous vein grafts are less well established. This review seeks to analyze available data for stent placement in this subset of non-STRESS/BENESTENT lesions.
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Lau KW, Ding ZP, Sigwart U, Lam L. Percutaneous interventional strategies in the treatment of chronic total coronary occlusions. Singapore Med J 2000; 41:468-70. [PMID: 11193123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Chronic total coronary occlusions which make up 10% to 20% of all interventional procedures in high-volume centres remain a vexing problem for invasive cardiologists for 2 main reasons. First, they are only successfully recanalised in about 60% of attempts with most failures resulting from an inability to cross the lesions. Laser guidewire appears to be a promising innovation in overcoming this obstacle. Second, after initially successful recanalisation with conventional balloon angioplasty (PTCA), a high restenosis rate (range, 45% to 75%) is observed. Stent placement, by conferring maximal luminal expansion, appears to have resolved this problem to a large extent; both observational and randomised studies indicate that after stent placement, restenosis rate is at least halved that of PTCA.
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Tsui EY, Chan JH, Cheung YK, Cheung CC, Tsui WC, Szeto ML, Lau KW, Yuen MK, Luk SH. Evaluation of therapeutic effectiveness of transarterial chemoembolization for hepatocellular carcinoma: correlation of dynamic susceptibility contrast-enhanced echoplanar imaging and hepatic angiography. Clin Imaging 2000; 24:210-6. [PMID: 11274885 DOI: 10.1016/s0899-7071(00)00204-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The objective of this study was to evaluate the therapeutic effectiveness of transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI). Seventeen patients with histopathologically proven HCC were included in this study. All patients underwent MR examinations with conventional T1- and T2-weighted images, gadolinium-enhanced images, and DSC-MRI before TACE treatment. Hepatic blood volume (HBV) maps were reconstructed from the time-intensity curves. The same MRI sequences and techniques were repeated 24 h and 6 weeks after TACE. Serial changes in tumor perfusion on HBV maps were correlated with vascularity in hepatic angiography. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. Heterogeneous enhancement was observed in all tumors before and immediately after TACE. Hyperperfusion was noted in most of the tumors on HBV map before TACE and moderate to marked hypoperfusion following TACE. The degree of tumor perfusion on HBV map correlated well with the vascularity in angiography. In conclusion, the noninvasive nature of DSC-MRI is useful to evaluate the effectiveness of TACE. Invasive procedures, such as angiography, are seldom necessary.
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Lau KW, Ding ZP, Sim LL, Sigwart U. Clinical and angiographic outcome after angiography-guided stent placement in small coronary vessels. Am Heart J 2000; 139:830-9. [PMID: 10783217 DOI: 10.1016/s0002-8703(00)90015-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Although it is widely accepted that stenting confers favorable angiographic and clinical results in coronary arteries >/=3.0 mm in diameter, the outcome of stent placement in smaller vessels remains largely unclear. METHODS AND RESULTS We sought to specifically determine the early and long-term clinical outcomes in a large series of 197 consecutive patients who underwent stent placement in 207 vessels <3.0 mm in diameter. Procedural success, accomplished in 97.3%, was accompanied by a significant reduction in lesion severity from 85% +/- 9% before to 3% +/- 7% diameter stenosis after the procedure (P =.0001) and a 0.5% incidence of subacute stent thrombosis. At 1 and 2 years of follow-up, survival rate without major target lesion-driven events was observed in 77.3% and 73.9% of patients, respectively. Repeat revascularization procedures accounted for most of these events; cardiac deaths (including those related to subacute stent thrombosis) and late (>30 days) myocardial infarctions were infrequent (2.4% and 1.0%, respectively). The 6-month angiographic binary instent restenosis rate was 30.1%. On multivariate analysis, diabetes mellitus (P =. 0275), small baseline reference vessel size (P =.0300), and stent size </=2.7 mm (P =.0111) were independently associated with an increased instent restenosis rate. CONCLUSIONS Optimal angiography-guided coronary stenting of vessels <3.0 mm in diameter in association with the stringent use of a poststent combined aspirin-ticlopidine antiplatelet regimen confers a low risk of stent thrombosis, an acceptable incidence of angiographic instent restenosis, and a favorable long-term clinical outcome.
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Lau KW, Ding ZP, Johan A, Hung JS. Mid-term clinical and angiographic follow-up outcome after placement of a new balloon expandable stent in native coronary arteries. Catheter Cardiovasc Interv 2000; 49:348-51. [PMID: 10700074 DOI: 10.1002/(sici)1522-726x(200003)49:3<348::aid-ccd27>3.0.co;2-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The widely disparate characteristics that exist among the different stent designs currently available for clinical use may impact on their acute and late angiographic and clinical results. The BeStent (Medtronic Instent, MN) is a relatively new stainless steel, laser-cut, serpentine stent design with only very limited data regarding its performance. In this report, we examined the results of 74 consecutive patients (54 men, 20 women; mean age, 58 years) treated with 76 BeStents in 75 native coronary arteries with a mean reference size of 2.8 mm. Successful stenting without 30-day major adverse cardiac complications was achieved in 97.3% of procedures, resulting in a significant improvement in diameter stenosis from 85% to 2% (P = 0.0001). Six-month angiographic restudy in 88% of patients revealed a per-lesion in-stent restenosis rate of 27%. At a mean follow-up period of 9.3 months, there were no deaths or myocardial infarctions. In summary, the present study demonstrates that the BeStent has an excellent performance profile, is associated with a low risk of stent thrombosis, and yields an acceptable restenosis rate despite the inclusion of a high proportion of patients with diabetes (41%) and small vessels (< 3.0 mm in diameter; 77%).
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Abstract
We report a rare case of stenotic double-orifice mitral valve of incomplete bridge type in a 40-year-old male. The fibrous bridge tissue between the leaflets was successfully split with a 24-mm Inoue balloon catheter using the stepwise dilation technique. Cathet. Cardiovasc. Intervent. 49:200-203, 2000.
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Abstract
We constructed a plasmid probe containing DNA sequences unique for chloroplast (Cp) genome and nuclear genome of Chlamydomonas reinhardtii. Using this probe and quantitative Southern blot analyses, we determined the content ratio of Cp DNA/nuclear DNA in total DNA isolated from cells grown in different conditions. Algal cells grown photoheterotrophically with acetate as an added carbon source contain the highest amount of Cp DNA compared with cells grown in other conditions tested. We investigated the effect of nitrogen limitation, 5-fluorodeoxyuridine treatment, cadmium exposure, photoautotrophic growth, and heterotrophic growth in darkness. The change in the Cp/nuclear DNA ratio in cells shifted from one growth condition to another depended on cell division; Cp DNA content in undivided cells remained constant. Therefore, the reduction of Cp DNA content was attributed by under replication rather than selective degradation of Cp DNA. Cells with low Cp DNA content often contained less reduced glutathione, suggesting the possible effect of redox status. Low Cp DNA content was detected in cells treated with inhibitors that block electron flow of photosystems and in mutants with PS I defective phenotype. On the basis of these data, we propose that in C. reinhardtii, Cp DNA replication be modulated by redox status.
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Lau KW, Kruth SA, Thorn CE, Vernau W, Moore P. Large granular lymphocytic leukemia in a mixed breed dog. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 1999; 40:725-8. [PMID: 10572670 PMCID: PMC1539817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
A mixed breed dog was diagnosed with large granular lymphocytic leukemia. Immunophenotypic analysis indicated the lymphocytes were CD3+, CD8+ T cells expressing the alpha beta T cell receptor and a leukointegrin, alpha d. Chemotherapy and splenectomy resulted in an initial reduction in the lymphocyte count.
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Ko JM, Cheung MH, Kwan MW, Wong CM, Lau KW, Tang CM, Lung ML. Genomic instability and alterations in Apc, Mcc and Dcc in Hong Kong patients with colorectal carcinoma. Int J Cancer 1999. [PMID: 10404094 DOI: 10.1002/(sici)1097-0215(19990820)84:4<404::aid-ijc13>3.0.co;2-l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Our aim was to reveal the significance of tumor-suppressor genes and genomic instability in 99 Hong Kong Chinese colorectal carcinoma (CRC) patients by PCR-LOH analysis and PCR-PTT assay. The frequencies of allelic loss of Apc, Mcc and Dcc and of APC truncation were 31.3% (15/48), 11.6% (5/43), 44.4% (20/45) and 46/93 (49.5%), respectively. The frequency of Apc LOH was similar to, the Mcc LOH was lower than, and the Dcc LOH was higher than that reported for Caucasians and Japanese. In Hong Kong CRC patients, the replication error-positive (RER(+)) phenotype occurred with a frequency of 10% (10/99), which was similar to other results using microsatellite markers where RER(+) frequencies ranged from 11% to 28%. The rates of genetic alteration in RER(+) tumors were lower in tumors harboring p53, Mcc and Dcc alterations; similar in Apc; and higher in Ki-ras tumors compared with RER(-) tumors, though these differences did not achieve statistical significance. None of the biomarkers examined were predictive of survival independently, but strong trends confirming earlier observations of associations between RER(+) phenotypes with proximal tumor location and poorly differentiated tumor status were noted. The RER(+) phenotype was correlated significantly to the less aggressive Duke's stage B and improved prognosis. Additionally, tumors with RER(+) phenotypes were positively correlated with young age and sex. Our results support the observation that a subset of younger male CRC patients in Hong Kong may develop CRC via the RER pathway and show differences in RER status and sex. A significantly higher percentage of older Hong Kong Chinese CRC patients had APC truncations. Int. J. Cancer (Pred. Oncol.) 84:404-409, 1999.
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Ko JM, Cheung MH, Kwan MW, Wong CM, Lau KW, Tang CM, Lung ML. Genomic instability and alterations in Apc, Mcc and Dcc in Hong Kong patients with colorectal carcinoma. Int J Cancer 1999; 84:404-9. [PMID: 10404094 DOI: 10.1002/(sici)1097-0215(19990820)84:4<404::aid-ijc13>3.0.co;2-l] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Our aim was to reveal the significance of tumor-suppressor genes and genomic instability in 99 Hong Kong Chinese colorectal carcinoma (CRC) patients by PCR-LOH analysis and PCR-PTT assay. The frequencies of allelic loss of Apc, Mcc and Dcc and of APC truncation were 31.3% (15/48), 11.6% (5/43), 44.4% (20/45) and 46/93 (49.5%), respectively. The frequency of Apc LOH was similar to, the Mcc LOH was lower than, and the Dcc LOH was higher than that reported for Caucasians and Japanese. In Hong Kong CRC patients, the replication error-positive (RER(+)) phenotype occurred with a frequency of 10% (10/99), which was similar to other results using microsatellite markers where RER(+) frequencies ranged from 11% to 28%. The rates of genetic alteration in RER(+) tumors were lower in tumors harboring p53, Mcc and Dcc alterations; similar in Apc; and higher in Ki-ras tumors compared with RER(-) tumors, though these differences did not achieve statistical significance. None of the biomarkers examined were predictive of survival independently, but strong trends confirming earlier observations of associations between RER(+) phenotypes with proximal tumor location and poorly differentiated tumor status were noted. The RER(+) phenotype was correlated significantly to the less aggressive Duke's stage B and improved prognosis. Additionally, tumors with RER(+) phenotypes were positively correlated with young age and sex. Our results support the observation that a subset of younger male CRC patients in Hong Kong may develop CRC via the RER pathway and show differences in RER status and sex. A significantly higher percentage of older Hong Kong Chinese CRC patients had APC truncations. Int. J. Cancer (Pred. Oncol.) 84:404-409, 1999.
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