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Cuthbertson DJ, Bell JA, Ng SY, Kemp GJ, Kivimaki M, Hamer M. Dynapenic obesity and the risk of incident Type 2 diabetes: the English Longitudinal Study of Ageing. Diabet Med 2016; 33:1052-9. [PMID: 26479063 DOI: 10.1111/dme.12991] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2015] [Indexed: 12/21/2022]
Abstract
AIM Obesity is a well-established risk factor for developing Type 2 diabetes. Evidence suggests that sarcopenia, the age-related decline in muscle mass and strength, may exacerbate diabetes risk in obese individuals. The aim of this study was to determine the combined effect of obesity and low muscle strength, dynapenia, on the risk of incident Type 2 diabetes in older adults. METHODS Participants were 5953 (1670 obese) men and women from the English Longitudinal Study of Ageing without known Type 2 diabetes at baseline and for whom handgrip strength, biochemical and other clinical data were collected. A diagnosis of Type 2 diabetes was recorded from self-reported physician diagnosis over 6 years. RESULTS For each unit increase in grip strength, there was a reduction in diabetes risk (age-, sex- and BMI adjusted HR; 0.98; 95% CI 0.96-0.99). The risk of Type 2 diabetes was elevated in all obese participants, but was greatest in those with low handgrip strength (HR = 4.93, 95% CI 2.85, 8.53) compared with non-obese individuals with high handgrip strength. Eleven per cent of the sample met the threshold for weakness (handgrip strength: men < 26 kg; women < 16 kg) that was associated with elevated Type 2 diabetes risk in obese (HR = 3.57, 95% CI 2.04, 6.24) but not in non-obese (HR = 0.86, 95% CI, 0.44, 1.68) compared with normal/non-obese participants. CONCLUSION Dynapenic obesity, determined by high BMI and low handgrip strength, is associated with increased risk of incident Type 2 diabetes in older people.
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Ng SY, Pua KC, Zahirrudin Z. Temporal bone squamous cell carcinoma - Penang experience. THE MEDICAL JOURNAL OF MALAYSIA 2015; 70:367-368. [PMID: 26988214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Temporal bone squamous cell carcinoma (TBSCC) is rare and poses difficulties in diagnosing, staging and management. We describe a case series with six patients who were diagnosed TBSCC, from January 2009 to June 2014, with median age of 62 years old. All patients presented with blood-stain discharge and external auditory canal mass, showing that these findings should highly alert the diagnosis of TBSCC. Three patients staged T3 and another three with T4 disease. High-resolution CT (HRCT) temporal findings were noted to be different from intraoperative findings and therefore we conclude that MRI should be done to look for middle ear involvement or other soft tissue invasion for more accurate staging. Lateral temporal bone resection (LTBR) and parotidectomy was done for four patients with or without neck dissection. Patients with positive margin, perineural invasion or parotid and glenoid involvement carry poorer prognosis and postoperative radiotherapy may improve the survival rate. One patient had successful tumor resection via piecemeal removal approach in contrast with the recommended en bloc resection shows that with negative margin achieved, piecemeal removal approach can be a good option for patients with T2-3 disease. In general, T4 tumor has dismal outcome regardless of surgery or radiotherapy given.
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Ng SY, Borysov M, Moramarco M, Nan XF, Weiss HR. Bracing Scoliosis - State of the Art. Curr Pediatr Rev 2015:CPR-EPUB-71906. [PMID: 26573162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/10/2015] [Accepted: 11/12/2015] [Indexed: 03/08/2023]
Abstract
Spinal bracing is indicated in moderate to severe curves during growth. Brace effectiveness in halting progression of adolescent idiopathic scolisosis has been shown in a Cochrane review and in a randomized controlled trial (RCT). The outcome of brace treatment is dependent on the extent of in-brace correction and compliance. We have reviewed the literature on bracing to determine the types of brace that offer the best in-brace correction. MATERIALS AND METHODS The literature has been searched for papers on bracing with documented in-brace corrections and long-term results . RESULTS The in-brace percentage of correction of asymmetric braces is generally higher than that of the symmetric braces. According to the literature found in our search, long-term corrections are possible when starting treatment early, at an immature stage and with asymmetric braces of recent standards. CONCLUSIONS Bracing today is supported by high quality evidence (Level I). Asymmetric braces have led to better corrections than that described for symmetric braces . An improvement of the average corrective effect has been described due to the latest CAD / CAM development. Long-term corrections are possible when starting brace treatment early, at an immature stage and with asymmetric braces of recent standards.
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Ng SY, Chong SY. What Do Mothers know about Neonatal Jaundice? Knowledge, Attitude and Practice of Mothers in Malaysia. THE MEDICAL JOURNAL OF MALAYSIA 2014; 69:252-256. [PMID: 25934954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
No abstract available.
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Turner EL, Metcalfe C, Donovan JL, Noble S, Sterne JAC, Lane JA, Avery KN, Down L, Walsh E, Davis M, Ben-Shlomo Y, Oliver SE, Evans S, Brindle P, Williams NJ, Hughes LJ, Hill EM, Davies C, Ng SY, Neal DE, Hamdy FC, Martin RM. Design and preliminary recruitment results of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP). Br J Cancer 2014; 110:2829-36. [PMID: 24867688 PMCID: PMC4056057 DOI: 10.1038/bjc.2014.242] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 04/08/2014] [Accepted: 04/10/2014] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Screening for prostate cancer continues to generate controversy because of concerns about over-diagnosis and unnecessary treatment. We describe the rationale, design and recruitment of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial, a UK-wide cluster randomised controlled trial investigating the effectiveness and cost-effectiveness of prostate-specific antigen (PSA) testing. METHODS Seven hundred and eighty-five general practitioner (GP) practices in England and Wales were randomised to a population-based PSA testing or standard care and then approached for consent to participate. In the intervention arm, men aged 50-69 years were invited to undergo PSA testing, and those diagnosed with localised prostate cancer were invited into a treatment trial. Control arm practices undertook standard UK management. All men were flagged with the Health and Social Care Information Centre for deaths and cancer registrations. The primary outcome is prostate cancer mortality at a median 10-year-follow-up. RESULTS Among randomised practices, 271 (68%) in the intervention arm (198,114 men) and 302 (78%) in the control arm (221,929 men) consented to participate, meeting pre-specified power requirements. There was little evidence of differences between trial arms in measured baseline characteristics of the consenting GP practices (or men within those practices). CONCLUSIONS The CAP trial successfully met its recruitment targets and will make an important contribution to international understanding of PSA-based prostate cancer screening.
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Parrott LA, Ng SY. A comparison between bitewing radiographs taken with rectangular and circular collimators in UK military dental practices: a retrospective study. Dentomaxillofac Radiol 2011; 40:102-9. [PMID: 21239573 DOI: 10.1259/dmfr/86968802] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim of this study was to determine any increase in the incidence of cone cut errors that adversely affected diagnostic yield resulting in more retakes using rectangular collimation with film holders in bitewing radiography. Comparisons were also made with other positioning errors that occurred when bitewings were taken with circular collimation, with and without film holders. METHODS A preliminary questionnaire was used to determine the year that rectangular collimation was adopted by military dental practice. 3 time-framed subsets, each of 1000 bitewing radiographs, were identified: subset 1, films taken with circular collimators without film holders; subset 2, films taken with circular collimators with film holders; and subset 3, films taken with rectangular collimators with film holders. Each subset was assessed for positioning errors of cone cut, horizontal overlap, vertical distortion and film centring. The χ(2) test was used to test significant differences amongst the three subsets. RESULTS The use of film holders with circular collimation significantly reduced the incidence of cone cut errors from 21.7% to 3.3%. There was an increase in the incidence of cone cut errors from 3.3% to 20.9% when rectangular collimation was used, but the actual number considered "rejects" was very small, only 0.1% (1 in 1000 films) in subset 2 and 0.3% (3 of 1000 films) in subset 3, when assessed for diagnostic yield. CONCLUSIONS This study provides evidence that rectangular collimation did not significantly affect the diagnostic yield of bitewing radiographs despite the presence of cone cut. Therefore, all practitioners should adopt rectangular collimation.
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Zhou YY, Lee LY, Ng SY, Hia CPP, Low KT, Chong YS, Goh DLM. UGT1A1 haplotype mutation among Asians in Singapore. Neonatology 2009; 96:150-5. [PMID: 19325249 DOI: 10.1159/000209851] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 09/29/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND The uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) enzyme is responsible for conjugation of the bilirubin in the liver as well as for drug metabolism. Some of the polymorphisms have been associated with an increased risk of neonatal hyperbilirubinemia which may explain the increased incidence of jaundice in an Asian population as well as exaggerated irinotecan-induced leukopenia. OBJECTIVE The local Asian incidence of hypomorphic haplotypes, defined as gene mutations known to have a reduced function, has not been described. Clinical correlation between the mutations and the need for phototherapy for hyperbilirubinemia was carried out. METHODS A cohort of 241 consecutive term infants delivered in the National University Hospital, Singapore, was recruited with parental consent. Cord blood was collected, and the promoter and coding regions of the UGT1A1 gene were sequenced. RESULTS Six known haplotypes and 2 novel haplotypes were identified: 1 wild type, 5 with reduced function, while the 2 novel ones were predicted to have decreased function. The frequency of these hypomorphic haplotypes was high. Among the 241 infants screened, 35% had 1 hypomorphic haplotype and 12% had 2 hypomorphic haplotypes. The frequency was also different among ethnic groups, with 48% Chinese, 64% Indian and 31% Malay infants having at least 1 hypomorphic haplotype (chi(2) test, p < 0.05). There was a trend seen between the number of G71R mutations and the need for phototherapy (chi2 test for trend, p < 0.05). CONCLUSIONS The local Asian incidence of hypomorphic haplotypes was high and there was a trend between the number of G71R mutations and the need for phototherapy. The G71R mutation may account for the increased incidence of neonatal jaundice seen in Asian populations.
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Toncheva V, Schacht E, Ng SY, Barr J, Heller J. Use of Block Copolymers of Poly(Ortho Esters) and Poly (Ethylene Glycol) Micellar Carriers as Potential Tumour Targeting Systems. J Drug Target 2008; 11:345-53. [PMID: 14668055 DOI: 10.1080/10611860310001633839] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Amphiphilic AB and ABA block copolymers have been prepared from poly (ortho esters) and poly (ethylene glycol). Such block copolymers readily form micellar dispersions in water, or buffers. The CMC is in the range of 3 x 10(-4)-5 x 10(-4) g/l which is a value low enough to assure retention of micelle integrity upon intravenous injection. The size, as determined by dynamic light scattering was in the 40-70 nm range. The micelles can be stored in lyophilized form for at lest 8 months and easily reconstituted to the original properties. The micelles are stable in PBS at pH 7.4 and 37 degrees C for 3 days and in a citrate buffer at pH 5.5 and 37 degrees C for 2 h. Stability in the presence of bovine serum albumin depends on the structure of the block copolymer and especially the length of the POE block.
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Tan TY, Ng SY, Teo L, Koh Y, Teok CH. Detection of plasmid-mediated AmpC in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. J Clin Pathol 2007; 61:642-4. [PMID: 18057079 DOI: 10.1136/jcp.2007.053470] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS This study investigated the prevalence of plasmid-mediated AmpC production in selected clinical isolates of Escherichia coli, Klebsiella species and Proteus mirabilis, and compared the results of boronic acid disc screening with conventional susceptibility testing for the detection of AmpC-positive isolates. METHODS E coli, Klebsiella species and P mirabilis with reduced susceptibility to amoxycillin-clavulanate, cefuroxime and cephalexin, but without phenotypic evidence of extended-spectrum beta-lactamases were screened for AmpC activity using enzyme-extraction methods. The presence of plasmid-mediated ampC was determined by multiplex PCR. Antibiotic susceptibilities were determined using both disc and dilution-based methods. A disc-based screening method for detection of AmpC-producing strains was evaluated using boronic acid as an inhibitor of AmpC, and cefoxitin as the antibiotic substrate. RESULTS Plasmid-mediated ampC was present in 26% of study isolates, with CMY-like enzymes detected predominantly in E coli and DHA-like enzymes predominantly in Klebsiella pneumoniae. Current susceptibility methods failed to detect a significant proportion of plasmid-mediated AmpC-producing isolates, with 33% of such strains interpreted as susceptible to third-generation cephalosporins using current Clinical Laboratory Standards Institute breakpoints. The boronic acid disc method showed sensitivity and specificity of 90% and 98% respectively in detecting AmpC-positive isolates. CONCLUSION The prevalence of plasmid-mediated ampC was high in the study population, and may be missed by conventional susceptibility testing methods. Inhibitor-based screening methods would improve detection of this emerging resistance phenotype.
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Ng SY, Wilkinson J. A salutary case of Fumaderm potentially masking the symptoms of bowel cancer and partial bowel obstruction. Br J Dermatol 2007; 157:825-6. [PMID: 17672877 DOI: 10.1111/j.1365-2133.2007.08098.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ngu RK, Brown JE, Whaites EJ, Drage NA, Ng SY, Makdissi J. Salivary duct strictures: nature and incidence in benign salivary obstruction. Dentomaxillofac Radiol 2007; 36:63-7. [PMID: 17403881 DOI: 10.1259/dmfr/24118767] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim of this study was to establish the incidence and character of salivary duct strictures by carrying out a 10 year retrospective review. Salivary gland obstruction is most commonly caused either by salivary calculi or duct strictures. These strictures or stenoses develop secondarily to inflammation in the duct wall and may be single or multiple. METHODS All reports of sialographic examinations performed on patients referred to the Dental Radiology Department in a London Dental Hospital between 1995 and 2004 were reviewed and those patients with symptoms of salivary obstruction identified. In total, 1362 sialograms using the conventional hand injection technique with water-soluble contrast media were performed on 1349 patients with obstructive symptoms during the 10-year period. RESULTS Of the 1362 sialograms performed, the reports revealed that 877 (64.4%) showed evidence of benign intraductal obstruction. The remaining 485 (35.6%) were normal. 642 of the cases (73.2%) revealing obstruction were reported to be due to salivary calculi, 198 due to duct strictures (22.6%) and the remaining 37 (4.2%) were considered to be due to mucous plugs. Detailed analysis of the patients with strictures showed they were more common in women with a mean age of 52 years. Single strictures were evident in 66.7% of cases while 33.3% showed multiple stenoses. Strictures were more common in the parotid duct (75.3%). 7% of patients presented with bilateral stenoses. CONCLUSION This is the largest review of duct strictures to be reported. It has shown that ductal stricture formation accounts for almost 25% of cases of benign salivary obstruction and appears to have been an under-recognized condition. Strictures more commonly affect parotid ducts and are typically found in the fourth, fifth or sixth decades, particularly in women.
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Tan TY, Ng SY. Comparison of Etest, Vitek and agar dilution for susceptibility testing of colistin. Clin Microbiol Infect 2007; 13:541-4. [PMID: 17371537 DOI: 10.1111/j.1469-0691.2007.01708.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In total, 172 isolates of Enterobacteriaceae, Acinetobacter spp., Pseudomonas aeruginosa and Stenotrophomonas maltophilia were tested for susceptibility to colistin by agar dilution, Etest and the Vitek 2 system. Isolates with a colistin MIC < or =2 mg/L were considered to be susceptible. Fifty-four (31%) Gram-negative isolates were resistant to colistin. Categorical agreement between agar dilution and Etest was 87%, and between agar dilution and Vitek 2 was 82%. Based on the data obtained, the Vitek 2 system was unreliable for detecting colistin resistance, and results obtained by Etest may require confirmation by a standard MIC susceptibility testing method.
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Ng SY, Yew WS. Nasotracheal tube occlusion from adenoid trauma. Anaesth Intensive Care 2006; 34:829-30. [PMID: 17183911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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Gundappa M, Ng SY, Whaites EJ. Comparison of ultrasound, digital and conventional radiography in differentiating periapical lesions. Dentomaxillofac Radiol 2006; 35:326-33. [PMID: 16940480 DOI: 10.1259/dmfr/60326577] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVES To carry out an in vivo comparative pilot study to evaluate the efficacy of ultrasound, digital (DR) and conventional plain film-based imaging (PF) in the differential diagnosis of periapical lesions. METHODS Fifteen patients aged between 13 years and 40 years with periapical lesions associated with anterior maxillary or mandibular teeth requiring endodontic surgery were selected and consented for the study. Pre-operative periapical radiographs (PF) and charge coupled device (CCD) DR were obtained. Measurements and provisional diagnoses of the apical areas were made by three specialist observers (two dental radiologists and one endodontist) on three separate occasions. Pre-operative ultrasound examinations were then performed and the images assessed by two specialist observers (ultrasonographer and endodontist) for the size, contents, vascular supply and a provisional diagnosis made as to whether the lesion was a cyst or granuloma. Endodontic surgery was performed including curettage of the apical tissues to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analysed. RESULTS On PF and DR the periapical lesions were readily identified but observers were unable to differentiate granuloma from cyst using either modality. Dimensional measurements were subject to greater interobserver variation on DR than on PF. Where sufficient buccal cortical bone had been resorbed, ultrasound imaging was straightforward but underestimated the size of the lesions compared with PF and DR. In all 15 cases, the ultrasound diagnosis agreed with the histopathological gold standard. CONCLUSIONS PF and DR enable diagnosis of periapical disease existence, but not of its nature; while ultrasound underestimates the extent of disease, but can provide accurate information on the pathological nature of the lesion.
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Tan TY, Ng SY. The in-vitro activity of colistin in gram-negative bacteria. Singapore Med J 2006; 47:621-4. [PMID: 16810437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
INTRODUCTION Colistin is a polypeptide antibiotic belonging to the polymyxins, and has been increasingly used for the treatment of multiresistant gram-negative infections. There is little current available data on the susceptibility of gram-negative bacilli to colistin, in part because susceptibility testing for colistin remains problematic, and also because the use of colistin is not widespread. This study tested clinical isolates of gram-negative bacilli for susceptibility to colistin using the reference susceptibility testing method of agar dilution. METHODS 102 strains of gram-negative bacilli were collected over a one-year period. Antibiotic susceptibility profiles were derived from disc susceptibility testing, and organisms were identified by standard microbiological methods. Isolates were selected for inclusion in the study using susceptibility profiles and epidemiological data. Minimum inhibitory concentrations to colistin were obtained by performing agar dilution according to a standardised method. RESULTS 30 percent of tested isolates were resistant to colistin. All Acinetobacter spp. and Escherichia coli were susceptible to colistin. Colistin resistance was detected predominantly in Stenotrophomonas maltophilia and Pseudomonas aeruginosa, but was also present in Enterobacter spp. and Klebsiella spp. CONCLUSION Colistin resistance is uncommon in the Enterobacteriaceae, but present in a significant proportion of S. maltophilia and P. aeruginosa isolates. From the results of this study, we recommend that susceptibility testing be performed whenever the clinical use of the polymyxins is considered.
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Songra AK, Ng SY, Farthing P, Hutchison IL, Bradley PF. Observation of tumour thickness and resection margin at surgical excision of primary oral squamous cell carcinoma—assessment by ultrasound. Int J Oral Maxillofac Surg 2006; 35:324-31. [PMID: 16356683 DOI: 10.1016/j.ijom.2005.07.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 07/13/2005] [Accepted: 07/26/2005] [Indexed: 11/16/2022]
Abstract
Tumour thickness and the status of resection margins are of prognostic significance in the treatment of oral cancer. In a single blind prospective study, 14 patients with biopsy proven oral squamous cell carcinoma had intraoral ultrasound imaging done preoperatively to measure tumour thickness, and intraoperatively to measure the deep surgical margin half way during resection. The cut surface was demonstrated on ultrasound by placing a metal, ultrasound-reflective, retractor into the surgical cut. The ultrasound measurements were compared to the subsequent histological measurements. Using the threshold of 5mm as indicator of margin clearance, there was agreement in 10 out of 14 cases between ultrasound and histology. Ultrasound detection of close surgical margins had a sensitivity of 83% and a specificity of 63%. For preoperative tumour thickness measurement, ultrasound imaging showed a high degree of correlation with histology (Pearson correlation coefficient=0.95, P<0.01). This original paper demonstrates that high resolution ultrasound imaging applied intraorally is a reliable tool in objectively assessing both the tumour thickness and the surgical margin clearance at the time of surgery.
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Tan EPS, Ng SY, Lim CT. Tensile testing of a single ultrafine polymeric fiber. Biomaterials 2005; 26:1453-6. [PMID: 15522746 DOI: 10.1016/j.biomaterials.2004.05.021] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2004] [Accepted: 05/12/2004] [Indexed: 11/30/2022]
Abstract
Due to the difficulty in handling micro and nanoscale fibers and measuring the small load required for deformation, mechanical properties of these fibers have not been widely characterized. In this study, tensile test of a single-strand polycaprolactone electrospun ultrafine fiber was performed using a nano tensile tester. The tested fiber exhibited the characteristic low strength and low modulus but high extensibility at room temperature. The mechanical properties were also found to be dependent on fiber diameter. Fibers with smaller diameter had higher strength but lower ductility due to the higher 'draw ratio' that was applied during the electrospinning process.
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Tagar HK, Ng SY. Diagnostic difficulties of complex root morphology: case study of a lower wisdom tooth. Br J Oral Maxillofac Surg 2005; 43:177-9. [PMID: 15749222 DOI: 10.1016/j.bjoms.2004.08.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2004] [Indexed: 11/16/2022]
Abstract
We did a panoramic radiographic examination of a symptomatic lower third molar for surgical planning and risk assessment. This showed a close association with the inferior dental canal, in addition to uncertain root morphology. A periapical radiograph showed evidence of additional smaller curved roots. Axial computed tomography (CT) with coronal reformats did not provide further information about the morphology of the root. After removal of the tooth, its root form was compared with the diagnostic images. The periapical radiograph provided the most information about the morphology of the additional roots. The axial and reformatted coronal CT showed accurately the position and tortuous course of the inferior dental canal.
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Hardee PSGF, Ng SY, Cashman M. Ultrasound imaging in the preoperative estimation of the size of tracheostomy tube required in specialised operations in children. Br J Oral Maxillofac Surg 2003; 41:312-6. [PMID: 14581023 DOI: 10.1016/s0266-4356(03)00125-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Some children are dependent on a tracheostomy for many years. As they grow, larger tracheostomy tubes may be required. Although tables of sizes of tracheas exist for different age groups, they are estimations of normal and may not be accurate for atypical cases. Chest radiographs and computed tomograms (CT) have been used experimentally to estimate tracheal sizes, but are not in regular use. METHOD High-resolution diagnostic ultrasound imaging was used to estimate the internal and external transverse tracheal diameter, and the depth of the trachea from the skin surface. This allowed selection of the correct standard pattern tracheostomy tube, or the construction of a custom-made tube preoperatively. RESULTS Four children with various abnormalities who were being considered for replacement tracheostomies were scanned. In one, diagnostic ultrasound confirmed that a new larger fenestrated tube could be placed, which subsequently improved vocalisation and respiration. In the other three, the scan showed there was no space to allow a larger tube to be placed. The standard tables were not suitable for any of these patients. CONCLUSION High-resolution ultrasound has a role in the non-invasive measurement of the size of the tube needed for specialised operations in children.
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Ng SY, Songra AK, Bradley PF. A new approach using intraoperative ultrasound imaging for the localization and removal of multiple foreign bodies in the neck. Int J Oral Maxillofac Surg 2003; 32:433-6. [PMID: 14552316 DOI: 10.1054/ijom.2002.0376] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An innovative method of using ultrasound imaging intraoperatively is reported. Multiple radiopaque and radiolucent foreign bodies within soft tissues were localized in theatre using high resolution ultrasonography. Depth of injury and vessel status were also ultrasonically assessed. Surgical removal of all foreign bodies was aided by intraoperative ultrasound guidance. In addition, this new approach of using intraoperative ultrasonography was pivotal in confirming the removal of all foreign bodies from the wound at the time of the operation.
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Ng SY, Dinesh SK, Tay SKH, Lee EH. Decreased access to health care and social isolation among young adults with cerebral palsy after leaving school. J Orthop Surg (Hong Kong) 2003; 11:80-9. [PMID: 12810977 DOI: 10.1177/230949900301100116] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To examine if leaving special schools has a negative impact on the health care and social isolation of young adults with cerebral palsy. METHODS Young adults with cerebral palsy, aged between 15 and 22 years, were divided into 2 cohorts: current students, who were still receiving services from special schools, and school-leavers, who had since been discharged from care. A questionnaire and physical examination were administered to assess the extent of disability, health care received by, and social isolation of these young adults. RESULTS School-leavers had a greater degree of dissability than did students, although the results were not statistically significant. Health care exposure to specialists, general practitioners, therapists physiotherapists, occupational therapists, and/or speech therapists), and medical social workers decreased after leaving school; with the exception of contact with general practitioners, these results were significant (p<0.05). The entire cohort was more socially isolated than a control cohort. School-leavers participated in fewer activities outside their homes, but showed less concern about their disability than did current students. CONCLUSIONS Young adults with cerebral palsy continue to have health care and lifestyle needs after leaving school, which are currently not being adequately met.
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Chen TW, Ng SY, Whaites EJ. Interpretation of skull radiographs for facial fractures by medical staff working in UK emergency departments: a pilot study. Dentomaxillofac Radiol 2003; 32:166-72. [PMID: 12917282 DOI: 10.1259/dmfr/49085346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES This was a pilot study to determine the ability of hospital doctors (1) to assess the technical quality of occipitomental (OM) radiographs and (2) to identify facial fractures. METHOD Twenty-two doctors from four UK Accident and Emergency (A&E) departments participated in a two part study: Part A was a postal questionnaire containing questions on demographic data, educational background, selection criteria, assessing radiographs and radiation protection; and Part B was a clinical viewing session to interpret 20 randomized OM radiographs divided into four groups; technically good and poor without fractures, and technically good and poor with fractures. RESULTS Study participants ranged from junior house officers to senior consultants. There was considerable variation in educational background and radiographic interpretation instruction at undergraduate and postgraduate level. OM radiographs constituted 10% of all skull radiographs examined per week, yet only 40% of the doctors felt confident when assessing technical quality. The majority of participants had only a limited knowledge of radiation protection legislation. During the viewing session, only 50% of the participants correctly identified those radiographs with fractures and those with technique errors. There was no significant difference between house officers and other grades of staff. A higher level of seniority did not equate with greater interpretative ability. Subjective confidence in assessing film quality did not correlate with the actual film viewing. CONCLUSION Only half of the A&E doctors taking part in the study were able to correctly assess film quality and identify facial fractures on OM radiographs. If the pilot sample is representative, then the findings are of considerable concern.
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Helle J, Barr J, Ng SY, Shen HR, Schwach-Abdellaoui K, Gurny R, Vivien-Castioni N, Loup PJ, Baehni P, Mombelli A. Development and applications of injectable poly(ortho esters) for pain control and periodontal treatment. Biomaterials 2002; 23:4397-404. [PMID: 12219830 DOI: 10.1016/s0142-9612(02)00180-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Poly(ortho esters) with a low glass transition temperature are semi-solid materials so that therapeutic agents can be incorporated at room temperature, without the use of solvents, by a simple mixing procedure. When molecular weights are limited to < 5 kDa, such materials are directly injectable using a needle size no larger than 22 gauge. Somewhat hydrophilic polymers can be produced by using the diketene acetal 3,9-diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane and triethylene glycol (TEG), while hydrophobic materials can be produced by using the diketene acetal and 1,10-decanediol. Molecular weight can be reproducibly controlled by using an excess of the diol, or by use of an alcohol that acts as a chain-stopper. Erosion rates can be controlled by varying the amount of latent acid incorporated into the polymer backbone. Toxicology studies using the TEG polymer have been completed and have shown that the polymer is non-toxic. Toxicology studies using the decanediol polymer are underway. Development studies using the TEG polymer aimed at providing a sustained delivery of an analgesic agent to control post-surgical pain are under development and human clinical trials using the decanediol polymer for the treatment of periodontitis are also underway.
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Lo WK, Li FK, Choy CB, Cheng SW, Chu WL, Ng SY, Lo CY, Lui SL. A retrospective survey of attitudes toward acceptance of peritoneal dialysis in Chinese end-stage renal failure patients in Hong Kong--from a cultural point of view. Perit Dial Int 2002; 21 Suppl 3:S318-21. [PMID: 11887844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
OBJECTIVE We undertook to study the attitudes toward dialysis of patients approaching end-stage renal failure and to analyze those attitudes from a cultural perspective. SETTING The study was performed in the pre-dialysis clinic of a tertiary referral renal center. PATIENTS All patients of Chinese ethnic origin seen in the pre-dialysis clinic from 1995 to 2000 for assessment of dialysis therapy were included. METHOD We performed a retrospective analysis of patient records with regard to attitudes of the patients toward dialysis, reasons for those attitudes, and factors that could lead to a subsequent change in attitude. RESULTS We assessed 462 patients over the 6-year period. Their mean age was 65.5 +/- 13.3 years, and 43.9% of the patients had diabetes. Peritoneal dialysis (PD) was offered to 74% of the patients, and hemodialysis (HD) to 3.9%. Among the patients offered PD, only 44% accepted dialysis. After counselling, 54% of the patients who originally declined PD ultimately accepted it. The major reasons for refusing PD were the ideas of "having lived long enough" and "lack of family support." Most other reasons could be overcome by counselling. Only a minority of patients demanded hemodialysis. CONCLUSIONS Declining an offer of dialysis was common. Counselling helped patients to accept PD. Certain cultural elements that hindered acceptance of dialysis were involved in the ideas of "having lived long enough" and "lack of family support." Those cultural elements should be tackled more specifically during counselling.
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Thiruchelvam JK, Songra AK, Ng SY. Intraoperative ultrasound imaging to aid abscess drainage--a technical note. Int J Oral Maxillofac Surg 2002; 31:442-3. [PMID: 12361082 DOI: 10.1054/ijom.2001.0188] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Diagnostic ultrasound is used widely to identify the presence of fluid collections preoperatively. Although its role in other parts of the body is well established, this report describes the technique of using diagnostic ultrasound intraoperatively to aid drainage of a large fascial space abscess in the head and neck. Following previously inadequate drainage of a large superficial abscess from a blindly placed drain, a second procedure was carried out, using ultrasound imaging to locate the persisting abscess. Furthermore, ultrasound demonstrated the adequacy of drainage and helped the surgeon to position the drain in the correct tissue space. We consider that intraoperative use of ultrasound has a role as a guidance tool to drain superficial fascial space abscesses in the head and neck region.
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