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Lai WY, Tang WYM, Loo SKF, Chan Y. Clinical characteristics and treatment outcomes of patients undergoing nail avulsion surgery for dystrophic nails. Hong Kong Med J 2011; 17:127-131. [PMID: 21471592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
OBJECTIVE To evaluate the clinical characteristics and treatment outcomes of patients undergoing surgical nail avulsion. DESIGN Retrospective study. SETTING Two dermatology centres in Hong Kong. PATIENTS A total of 32 patients with nail diseases who underwent 33 nail avulsion procedures were reviewed from case records. MAIN OUTCOME MEASURES Age, gender, co-morbidities, disease duration, clinical features, histopathology and fungal culture of nail plate, nail bed specimen for fungal culture in appropriate cases, and postoperative outcome. RESULTS The mean age of the patients at the time of nail avulsion was 54 (range, 27-86) years. The most frequent preoperative findings were thickened nails (23 specimens, 70%) and discolouration (20 specimens, 61%). Onychomycosis was the most common pre-consultative diagnosis (20 specimens, 61%). Prior to nail avulsion, topical or systemic treatment had been tried in more than half of the cases. Histopathology of the avulsed nails confirmed onychomycosis in 24 (73%) of specimens. The clinical cure rate was 88% and the mycologic cure rate was 100%. The procedure was well tolerated without significant complications. Relapse was only noted in three (9%) of the patients having nail avulsions. The time for full re-growth ranged from 5 to 10 months. CONCLUSIONS Total nail avulsion is an effective management option for patients whose diagnosis of onychomycosis was doubtful, and constitutes a treatment armamentarium especially for patients with single or oligo-onychomycosis.
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Chan Y, Mok CC, Tang WYM. Erythema elevatum diutinum in systemic lupus erythematosus. Rheumatol Int 2010; 31:259-62. [PMID: 20652813 DOI: 10.1007/s00296-010-1574-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Accepted: 07/11/2010] [Indexed: 11/24/2022]
Abstract
Erythema elevatum diutinum (EED) is a rare chronic form of leukocytoclastic vasculitis with unknown etiology. EED has been described in association with hematological malignancies, infections and a number of rheumatological diseases. We report a patient with systemic lupus erythematosus (SLE) who presented with intermittent attacks of tender nodules and plaques on the shins and ankles for 6 months. Skin biopsy confirmed the diagnosis of EED. Treatment with dapsone resulted in complete resolution of the skin lesions. EED is rarely reported in SLE, and its presentation and treatment is reviewed.
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Chan Y, Ching JYL, Cheung CMY, Tsoi KKF, Polder-Verkiel S, Pang SHY, Quan WL, Kee KM, Chan FKL, Sung JJY, Wu JCY. Development and validation of a disease-specific quality of life questionnaire for gastro-oesophageal reflux disease: the GERD-QOL questionnaire. Aliment Pharmacol Ther 2010; 31:452-60. [PMID: 19878152 DOI: 10.1111/j.1365-2036.2009.04187.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND A simple and meaningful health-related quality of life (HRQoL) questionnaire for gastro-oesophageal reflux disease (GERD) patients is lacking. AIM To develop and validate a disease-specific HRQoL instrument (GERD-QOL) for GERD patients. METHODS An 18-item questionnaire was generated to measure the impact of GERD on sleep, exercise, diet, need for medication, sex life, work, social activity and psychological well-being. GERD patients were invited to complete the GERD-QOL, a visual analogue scale (VAS) and a validated Chinese generic QoL (SF-36) questionnaire before and after esomeprazole treatment. Factor analysis was performed for item selection and psychometric properties were measured. An English version was developed by a forward-backward translation process. RESULTS A final 16-item GERD-QOL questionnaire was developed. The items were grouped into four subscales (Daily activity, Treatment effect, Diet, and Psychological well-being) after factor analysis. GERD-QOL had good item-internal consistency (Cronbach's alpha: 0.64-0.88), high test-retest reliability (intraclass correlation coefficient: 0.73-0.94, P < 0.001). Its subscale scores were correlated with SF-36 and VAS, which demonstrated high construct validity (P < 0.001). Discriminant validity was verified by correlating GERD-QOL scores with symptom severity (P < 0.001). Responsiveness after esomeprazole treatment was significant (paired-t-test P < 0.001). An English version of GERD-QOL was developed. CONCLUSION The instrument, GERD-QOL, is valid and reliable.
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Chan Y, Carrington M, Calderone A, Stewart S. A Randomised Controlled Study of a Multidisciplinary, Home-based Health Care Program for Privately Insured Cardiac Patients: The Young @ Heart Study. Heart Lung Circ 2010. [DOI: 10.1016/j.hlc.2010.06.591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Chan Y, Beltrame J, Wilson D. The Role of Calcium Channels in Endothelin-1-Mediated Vasoconstriction of Rat Mesenteric Arteries. Heart Lung Circ 2010. [DOI: 10.1016/j.hlc.2010.06.707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chiong E, Kesavan A, Mahendran R, Chan Y, Tan T, Esuvaranathan K. MP-13.01: Human Gene Polymorphism and Response to Bacillus Calmette-Guerin Immunotherapy for Superficial Bladder Cancer. Urology 2009. [DOI: 10.1016/j.urology.2009.07.870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Moskowitz A, Chan Y, Bruns J, Levine S. 229: A Survey of Emergency Physician and Stroke Specialist Beliefs and Expectations Regarding Telestroke. Ann Emerg Med 2009. [DOI: 10.1016/j.annemergmed.2009.06.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Wong G, Ma Y, Chan Y, Fang J, Li Y, Pan Y, Leung T, Liu F. Comparative Study Of Food Allergy In Rural And Urban Chinese School Children. J Allergy Clin Immunol 2009. [DOI: 10.1016/j.jaci.2008.12.1065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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McArdle K, Shokuhi S, Chan Y, Vishwanath L, Brown H. Are there preoperative predictors for invasive disease in DCIS? Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-3014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Abstract #3014
Introduction: Ductal carcinoma in situ (DCIS) of the breast is defined as a proliferation of malignant epithelial cells within breast ducts without evidence of invasion through the basement membrane. Core needle biopsy (CNB) is used to sample both symptomatic and screen detected breast lesions preoperatively. However in a proportion of patients invasive disease is identified following surgical excision and as a result an upstaged patient may need to undergo additional surgery for axillary nodal evaluation such as sentinel lymph node biopsy (SLNB). Our aim was to evaluate predictive factors for invasive disease in this group.
 Method: Data from all patients with preoperative diagnosis of DCIS on core biopsy between February 2006 and December 2007 were analysed. Demographic data, screening /symptomatic presentation, palpability, size and histological features of DCIS on core biopsy including presence/absence of comedo necrosis, size of post operative invasion when present and result of axillary staging in this group was recorded. All patients with invasive disease had axillary staging.
 Results: A total of 75 patients were identified (all female), median age 63 (range 38-77). 72% (54/75) were screen detected. All palpable lesions were in the symptomatic group (13/19). Invasive disease was identified in 18 (24%) on post operative histology (2 micro-invasions). Only one patient with invasive disease had axillary involvement.
 
 Invasive disease was significantly higher in symptomatic and palpable lesions (P=0.04). Size of the lesion was significantly larger in the invasive group (P=0.04). High grade histology or presence of comedo necrosis was not a predictor of invasive disease in our series.
 Conclusion: A quarter of patients were upstaged and required axillary staging. 50% of symptomatic, palpable lesions larger than 20mm were found to be invasive on final histology, this group accounted for the only positive axilla. Symptomatic patients presenting with large, palpable areas of DCIS should be considered for axillary ultrasound scan and/or SLNB.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3014.
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Chen L, Yung K, Chan Y, Shum D, Bolam J. The proNGF-p75NTR-Sortilin Signalling Complex as New Target for the Therapeutic Treatment of Parkinsons Disease. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2008; 7:512-23. [DOI: 10.2174/187152708787122923] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Chan Y, Tang WYM, Lam WY, Loo SKF, Li SPS, Au AWM, Leung WY, Kwan CK, Lo KK. A cluster of chilblains in Hong Kong. Hong Kong Med J 2008; 14:185-191. [PMID: 18525086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
OBJECTIVE To report a recent clustering of chilblain cases in Hong Kong. DESIGN Case series. SETTING A regional hospital and a social hygiene clinic in the New Territories West, Hong Kong. PATIENTS Patients with a clinical diagnosis of chilblains in February 2008. RESULTS Eleven patients with chilblains were identified; seven (64%) gave an antecedent history of prolonged exposure to cold. They all presented with erythematous or dusky erythematous skin lesions affecting the distal extremities, especially fingers and toes. Laboratory tests revealed elevated antinuclear antibodies titres in two, positive rheumatoid factor in two, presence of cold agglutinins in one, and a raised anti-DNA titre (>300 IU/mL) in one. Skin biopsies were performed in six patients, four of them showed typical histopathological features of chilblains. In the patient with systemic lupus erythematosus, features of vasculitis were suspected, and in the one with pre-existing juvenile rheumatoid arthritis, there were features of livedo vasculitis. In 10 (91%) of the patients, the skin lesions had resolved when they were last assessed (at the end of March 2008), but had persisted in the patient who had pre-existing systemic lupus erythematosus. CONCLUSION The recent clustering of chilblains was possibly related temporally to the prolonged cold weather at the end of January to mid-February. In our series, most of the patients developed chilblains as an isolated condition and resolved spontaneously within a few weeks. Laboratory tests and skin biopsies for chilblains are not necessary, unless the condition persists, the diagnosis in doubt or an underlying systemic disease is suspected.
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Wilson A, Arcese P, Keller LF, Pruett CL, Winker K, Patten MA, Chan Y. The contribution of island populations to in situ genetic conservation. CONSERV GENET 2008. [DOI: 10.1007/s10592-008-9612-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Soni P, Chan Y, Eswaran H, Wilson JD, Murphy P, Lowery CL. Spatial-temporal analysis of fetal bio-magnetic signals. J Neurosci Methods 2007; 162:333-45. [PMID: 17335907 PMCID: PMC2702244 DOI: 10.1016/j.jneumeth.2006.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 12/04/2006] [Accepted: 12/20/2006] [Indexed: 11/23/2022]
Abstract
Non-invasive technique such as magneto-encephalography (MEG), initially pioneered to study human brain signals, has found many other applications in medicine. SQUID(1) Array for Reproductive Assessment (SARA) is a unique non-invasive scanning-device developed at the University of Arkansas for Medical Sciences (UAMS) that can detect fetal brain and other signals. The fetal magneto-encephalography (fMEG) signals often have many bio-magnetic signals mixed in. Examples include the movement of the fetus or muscle contraction of the mother. As a result, the recorded signals may show unexpected patterns, other than the target signal of interest. These "interventions" make it difficult for a physician to assess the exact fetal condition, including its response to various stimuli. We propose using intervention analysis and spatial-temporal auto-regressive moving-average (STARMA) modeling to address the problem. STARMA is a statistical method that examines the relationship between the current observations as a linear combination of past observations as well as observations at neighboring sensors. Through intervention analysis, the change in a pattern due to "interfering" signals can be accounted for. When these interferences are "removed," the end product is a "template" time series, or a typical signal from the target of interest. In this research, a "universal" template is obtained. The template is then used to detect intervention in other datasets by the method of template matching. By this method, it is possible to detect if there is an intervention in any dataset. It will assist physicians in monitoring the actual signal generated by fetal brain and other organs of interest.
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Li W, Chiu L, Lam W, Wong W, Chan Y, Ho Y, Wong E, Wong Y, Ooi V. Ethyl acetate extract of Chinese medicinal herb Sarcandra glabra induces growth inhibition on human leukemic HL-60 cells, associated with cell cycle arrest and up-regulation of pro-apoptotic Bax/Bcl-2 ratio. Oncol Rep 2007. [DOI: 10.3892/or.17.2.425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Chiong E, Thamboo T, Teh M, Chan Y, Esuvaranathan K. MP-15.07. Urology 2006. [DOI: 10.1016/j.urology.2006.08.474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rafferty MA, Siewerdsen JH, Chan Y, Moseley DJ, Daly MJ, Jaffray DA, Irish JC. Investigation of C-arm cone-beam CT-guided surgery of the frontal recess. Laryngoscope 2006; 115:2138-43. [PMID: 16369157 DOI: 10.1097/01.mlg.0000180759.52082.45] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE/HYPOTHESIS A cone-beam CT (CBCT) imaging system based on a mobile C-arm (Siemens PowerMobil) incorporating a high-performance flat-panel detector (Varian PaxScan) has been developed in our laboratory. We hypothesize that intraoperative C-arm CBCT provides image quality and guidance performance sufficient to assist surgical approach to the frontal recess. STUDY DESIGN A preclinical prospective study was conducted using six cadaver heads to assess the performance characteristics and the potential clinical utility of this imaging system. METHODS The mobile C-arm was employed for intraoperative CBCT guidance of the endoscopic approach to twelve frontal recesses. RESULTS The imaging system is capable of sub-mm 3D spatial resolution with bone and soft-tissue visibility and a field of view sufficient for guidance of head and neck surgery. The system can generate intraoperative, volumetric CT images rapidly with an acceptably low radiation exposure to the patient and with image quality sufficient for most surgical tasks. Moreover, the system is portable and compatible with the surgical setup, providing excellent access to the patient. Finally, the accuracy of the system is not bound to a registration process. CONCLUSIONS The ability to create updated images as surgery progresses introduces the concept of 'near-real-time' CT guidance for head and neck surgery. We found that the use of CBCT increased surgical confidence in accessing the frontal recess, resolved ambiguities with anatomical variations, and provided valuable teaching information to surgeons in training in both preoperative planning and correlation between tri-planar CT scans and intraoperative endoscopic findings.
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Chan Y, Meng MQH, Wang X, Wu JCY. A prototype design of a wireless capsule endoscope. Appl Bionics Biomech 2006. [DOI: 10.1533/abbi.2006.0023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Chan Y, Lavery R, Kalira D, Nasir A, Kwon R, Livingston D. Initial Assessment and Management of Facial Gunshot Injuries. Ann Emerg Med 2005. [DOI: 10.1016/j.annemergmed.2005.06.139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bowen RAR, Chan Y, Ruddel ME, Hortin GL, Csako G, Demosky SJ, Remaley AT. Immunoassay interference by a commonly used blood collection tube additive, the organosilicone surfactant silwet L-720. Clin Chem 2005; 51:1874-82. [PMID: 16099932 DOI: 10.1373/clinchem.2005.055400] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND A small number of immunoassays on several different types of analyzers were recently adversely affected by tube additives in Becton Dickinson (BD) Vacutainer SST, SST II, and Microtainer blood collection tubes. We examined the effect of a commonly used tube surfactant, Silwet L-720, on immunoassays and the mechanism for the interference. METHODS Immunoassays were performed on serum supplemented with Silwet L-720 on the IMMULITE 2500 and AxSYM analyzers. Direct effects of the surfactant on the chemiluminescent detection step of immunoassays and on antibody immobilization on the solid phase were examined. RESULTS Increasing the final surfactant concentration from 0 to 400 mg/L in serum significantly increased (approximately 51%) the apparent total triiodothyronine (TT3) concentrations measured on the IMMULITE 2500 but not the AxSYM analyzer. Several other competitive, but not noncompetitive, assays were also significantly affected by the surfactant on the IMMULITE 2500 analyzer. The effect was independent of serum components, and the surfactant had no direct effect on chemiluminescence reactions. The capture antibody, however, was displaced from the solid phase by incubation with solutions containing surfactant under conditions similar to the IMMULITE TT3 assay. CONCLUSIONS The Silwet L-720 surfactant, which is used to coat the inner surfaces of tubes, appears to account for previously reported immunoassay interference by BD Vacutainer SST blood collection tubes. One of the mechanisms for the interference is the desorption of antibodies from the solid phase by the surfactant. The results identify an important factor in the selection of suitable blood collection tube surfactants and provide an approach for solving similar tube-assay interference problems in the future.
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Lehmberg RH, Chan Y. Near-field nonuniformities in angularly multiplexed KrF fusion lasers with induced spatial incoherence. APPLIED OPTICS 2005; 44:2805-17. [PMID: 15943333 DOI: 10.1364/ao.44.002805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Induced spatial incoherence (ISI) has been proposed for KrF laser drivers to achieve the high degree of spatial beam uniformity required for direct-drive inertial confinement fusion. Although ISI provides ultrasmooth illumination at the far field of the laser, where the target is located, it can still allow the beams in the quasi-near field to develop a time-averaged spatial structure. This speckle, which arises primarily from random-phase aberration, builds up as the laser beams propagate away from the pupil plane located at the final amplifier stage; it is distinct from any structure imposed by gain nonuniformities in the amplifiers. Because of the spatial incoherence, the speckle is significantly smaller than that experienced by coherent beams. Nevertheless, it remains a damage issue, especially for the long beam delay paths required in angularly multiplexed KrF lasers. We develop a novel algorithm for calculating the time-integrated intensities; compare simulations and measurements of the near-field speckle in the Nike KrF laser; and explore options, such as aberration reduction and optical relaying, for controlling the problem in future angularly multiplexed KrF drivers.
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Bowen RAR, Chan Y, Cohen J, Rehak NN, Hortin GL, Csako G, Remaley AT. Effect of blood collection tubes on total triiodothyronine and other laboratory assays. Clin Chem 2004; 51:424-33. [PMID: 15576427 DOI: 10.1373/clinchem.2004.043349] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Increased total triiodothyronine (TT(3)) assay results in apparently euthyroid patients triggered an investigation of the effect of blood collection tubes on serum TT(3) and other laboratory assays. METHODS We examined potential assay interference for three types of tubes: plastic Greiner Bio-One Vacuette; glass Becton Dickinson (BD) Vacutainer; and plastic BD Vacutainer SST tubes. Serum samples from apparently healthy volunteers (age range, 30-60 years; 15 males and 34 females) were collected in different tube types and analyzed in 17 immunoassays (n = 49), 30 clinical chemistry tests (n = 20), and 33 immunology assays (n = 15). Tube effects were also examined by adding pooled serum to different tube types. RESULTS TT(3) values, when measured by the IMMULITE 2000 but not the AxSYM analyzer, were significantly higher (P <0.0001) for SST (2.81 nmol/L) than either glass (2.15 nmol/L) or Vacuette (2.24 nmol/L) tubes. The effect was large enough to substantially shift the distribution of patient values, increasing the percentage of values above the reference interval from 11.3% to 35.8%. The degree of interference from SST tubes on TT(3) differed among various tube lots and could be attributed to a tube additive shared by other plastic tubes. Results from several other tests statistically differed among tube types, but differences were not considered to be clinically significant. CONCLUSIONS Assay interferences from blood collection tubes represent challenges to clinical laboratories because they are not detected by the usual quality-control or proficiency testing programs. Laboratories can, however, address this problem by monitoring distribution of patients' results.
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Soni P, Chan Y, Preissl H, Eswaran H, Wilson J, Murphy P, Lowery CL. Spatial-temporal analysis of non-stationary fMEG data. NEUROLOGY & CLINICAL NEUROPHYSIOLOGY : NCN 2004; 2004:100. [PMID: 16012614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Magnetoencephalography (MEG) is a technique used to non-invasively record neuromagnetic fields generated by the human brain. Our new SARA (SQUID Array for Reproductive Assessment) is a unique MEG device designed specifically for the study of the fetal neurophysiology. During the acquistion of fetal magnetoencephalography (fMEG), many other interfering bio-magnetic signals are collected as well. Examples include the movement of fetus or muscle contraction of the mother. As a result, the recorded signals may show unexpected patterns, other than the target signal of interest. These interventions makes it difficult for a physician to assess the exact fetal condition, including its response to various stimuli. We propose using intervention analysis and spatial-temporal autoregressive moving average (STARMA) modeling to address the problem. STARMA is a statistical method that examines the relationship between the current observations as a linear combination of past observations, as well as observations at neighboring sites. Through intervention analysis, the change in pattern due to interfering signals can be well accounted for. When these interferences are removed, the end product is a template time series, or a typical signal from the target of interest thus providing a more reliable means to monitor the actual signals generated by the fetal brain and other organs of interest.
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Wu X, Chan Y, Preissl H, Eswaran H, Wilson J, Murphy P, Lowery CL. Time-frequency and coherence analysis of fMEG signals. NEUROLOGY & CLINICAL NEUROPHYSIOLOGY : NCN 2004; 2004:11. [PMID: 16012599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Fetal magnetoencephalographic (fMEG) measurements are performed with interference from the fetal and maternal magnetocardiogram (MCG). Fetal movement, fetal breathing, fetal eye blinks or eye rollings and maternal muscle-contraction may generate detectable signals. These factors can be called "interventions," which can be manifested in space and/or time. They make the fMEG signals nonstationary. By examining temporal relationship of the multi-channel records, we are able to find the spatial signature of these "interventions." The aim of this study is to examine nonstationarity in single channel and nonhomogeniety in multiple channels of the fMEG data. Preliminary results are reported here, and may be used in further studies, leading toward intervention identification, and ultimately fetal state determination.
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Xu M, Chan Y, Fischer SH, Remaley AT. Automated procedure for improving the RNA isolation step in viral load testing for human immunodeficiency virus. J Clin Microbiol 2004; 42:439-40. [PMID: 14715800 PMCID: PMC321698 DOI: 10.1128/jcm.42.1.439-440.2004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An automated RNA isolation procedure on the Qiagen BioRobot is described for performing viral load tests for human immunodeficiency virus (HIV) with the Amplicor HIV type 1 test. The new procedure improves the precision of the assay and requires significantly less labor than the presently used manual RNA isolation procedure.
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