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  1. A Talip B, Snelling WJ, Sleator RD, Lowery C, Dooley JSG
    BMC Microbiol, 2018 11 26;18(1):196.
    PMID: 30477427 DOI: 10.1186/s12866-018-1335-0
    BACKGROUND: The field of diagnostics continues to advance rapidly with a variety of novel approaches, mainly dependent upon high technology platforms. Nonetheless much diagnosis, particularly in developing countries, still relies upon traditional methods such as microscopy. Biological material, particularly nucleic acids, on archived glass slides is a potential source of useful information both for diagnostic and epidemiological purposes. There are significant challenges faced when examining archived samples in order that an adequate amount of amplifiable DNA can be obtained. Herein, we describe a model system to detect low numbers of bacterial cells isolated from glass slides using (laser capture microscopy) LCM coupled with PCR amplification of a suitable target.

    RESULTS: Mycobacterium smegmatis was used as a model organism to provide a proof of principle for a method to recover bacteria from a stained sample on a glass slide using a laser capture system. Ziehl-Neelsen (ZN) stained cells were excised and catapulted into tubes. Recovered cells were subjected to DNA extraction and pre-amplified with multiple displacement amplification (MDA). This system allowed a minimum of 30 catapulted cells to be detected following a nested real-time PCR assay, using rpoB specific primers. The combination of MDA and nested real-time PCR resulted in a 30-fold increase in sensitivity for the detection of low numbers of cells isolated using LCM.

    CONCLUSIONS: This study highlights the potential of LCM coupled with MDA as a tool to improve the recovery of amplifiable nucleic acids from archived glass slides. The inclusion of the MDA step was essential to enable downstream amplification. This platform should be broadly applicable to a variety of diagnostic applications and we have used it as a proof of principle with a Mycobacterium sp. model system.

    Matched MeSH terms: Sensitivity and Specificity
  2. A VBR, Yusop Z, Jaafar J, Aris AB, Majid ZA, Umar K, et al.
    J Pharm Biomed Anal, 2016 Sep 05;128:141-148.
    PMID: 27262107 DOI: 10.1016/j.jpba.2016.05.026
    In this study a sensitive and selective gradient reverse phase UPLC-MS/MS method was developed for the simultaneous determination of six process related impurities viz., Imp-I, Imp-II, Imp-III, Imp-IV, Imp-V and Imp-VI in darunavir. The chromatographic separation was performed on Acquity UPLC BEH C18 (50 mm×2.1mm, 1.7μm) column using gradient elution of acetonitrile-methanol (80:20, v/v) and 5.0mM ammonium acetate containing 0.01% formic acid at a flow rate of 0.4mL/min. Both negative and positive electrospray ionization (ESI) modes were operated simultaneously using multiple reaction monitoring (MRM) for the quantification of all six impurities in darunavir. The developed method was fully validated following ICH guidelines with respect to specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, robustness and sample solution stability. The method was able to quantitate Imp-I, Imp-IV, Imp-V at 0.3ppm and Imp-II, Imp-III, and Imp-VI at 0.2ppm with respect to 5.0mg/mL of darunavir. The calibration curves showed good linearity over the concentration range of LOQ to 250% for all six impurities. The correlation coefficient obtained was >0.9989 in all the cases. The accuracy of the method lies between 89.90% and 104.60% for all six impurities. Finally, the method has been successfully applied for three formulation batches of darunavir to determine the above mentioned impurities, however no impurity was found beyond the LOQ. This method is a good quality control tool for the trace level quantification of six process related impurities in darunavir during its synthesis.
    Matched MeSH terms: Sensitivity and Specificity
  3. Abas FS, Shana'ah A, Christian B, Hasserjian R, Louissaint A, Pennell M, et al.
    Cytometry A, 2017 06;91(6):609-621.
    PMID: 28110507 DOI: 10.1002/cyto.a.23049
    The advance of high resolution digital scans of pathology slides allowed development of computer based image analysis algorithms that may help pathologists in IHC stains quantification. While very promising, these methods require further refinement before they are implemented in routine clinical setting. Particularly critical is to evaluate algorithm performance in a setting similar to current clinical practice. In this article, we present a pilot study that evaluates the use of a computerized cell quantification method in the clinical estimation of CD3 positive (CD3+) T cells in follicular lymphoma (FL). Our goal is to demonstrate the degree to which computerized quantification is comparable to the practice of estimation by a panel of expert pathologists. The computerized quantification method uses entropy based histogram thresholding to separate brown (CD3+) and blue (CD3-) regions after a color space transformation. A panel of four board-certified hematopathologists evaluated a database of 20 FL images using two different reading methods: visual estimation and manual marking of each CD3+ cell in the images. These image data and the readings provided a reference standard and the range of variability among readers. Sensitivity and specificity measures of the computer's segmentation of CD3+ and CD- T cell are recorded. For all four pathologists, mean sensitivity and specificity measures are 90.97 and 88.38%, respectively. The computerized quantification method agrees more with the manual cell marking as compared to the visual estimations. Statistical comparison between the computerized quantification method and the pathologist readings demonstrated good agreement with correlation coefficient values of 0.81 and 0.96 in terms of Lin's concordance correlation and Spearman's correlation coefficient, respectively. These values are higher than most of those calculated among the pathologists. In the future, the computerized quantification method may be used to investigate the relationship between the overall architectural pattern (i.e., interfollicular vs. follicular) and outcome measures (e.g., overall survival, and time to treatment). © 2017 International Society for Advancement of Cytometry.
    Matched MeSH terms: Sensitivity and Specificity
  4. Abbas AA, Guo X, Tan WH, Jalab HA
    J Med Syst, 2014 Aug;38(8):80.
    PMID: 24957396 DOI: 10.1007/s10916-014-0080-7
    In a computerized image analysis environment, the irregularity of a lesion border has been used to differentiate between malignant melanoma and other pigmented skin lesions. The accuracy of the automated lesion border detection is a significant step towards accurate classification at a later stage. In this paper, we propose the use of a combined Spline and B-spline in order to enhance the quality of dermoscopic images before segmentation. In this paper, morphological operations and median filter were used first to remove noise from the original image during pre-processing. Then we proceeded to adjust image RGB values to the optimal color channel (green channel). The combined Spline and B-spline method was subsequently adopted to enhance the image before segmentation. The lesion segmentation was completed based on threshold value empirically obtained using the optimal color channel. Finally, morphological operations were utilized to merge the smaller regions with the main lesion region. Improvement on the average segmentation accuracy was observed in the experimental results conducted on 70 dermoscopic images. The average accuracy of segmentation achieved in this paper was 97.21 % (where, the average sensitivity and specificity were 94 % and 98.05 % respectively).
    Matched MeSH terms: Sensitivity and Specificity
  5. Abd Aziz NAS, Mohd Fahmi Teng NI, Kamarul Zaman M
    Clin Nutr ESPEN, 2019 02;29:77-85.
    PMID: 30661705 DOI: 10.1016/j.clnesp.2018.12.002
    BACKGROUND & AIMS: Malnutrition is common among hospitalized elderly patients, and the prevalence is increasing not only in Malaysia but also in the rest of the world. The Geriatric Nutrition Risk Index (GNRI) and the Mini Nutritional Assessment (MNA) were developed to identify malnourished individuals among this group. The MNA was validated as a nutritional assessment tool for the elderly. The GNRI is simpler and more efficient than the MNA, but studies on the use of the GNRI and its validity among the Malaysian population are absent. This study aimed to determine the prevalence of malnourished hospitalized elderly patients and assess the criterion validity of the GNRI and MNA among the geriatric Malaysian population against the reference standard for malnutrition, the Subjective Global Assessment (SGA), and determine whether the optimal cutoff value of the GNRI is suitable for the Malaysian population and determine the optimal tool for use in this population.

    METHODS: A cross-sectional study was conducted among 134 geriatric patients with a mean age of 68.9 ± 8.4 who stayed at acute care wards in Hospital Tuanku Ampuan Rahimah, Klang from July 2017 to August 2017. The SGA, MNA, and GNRI were administered through face-to-face interviews with all the participants who gave their consent. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the GNRI and MNA were analyzed against the SGA. Receiver-operating characteristic (ROC) curve analysis was used to obtain the area under the curve (AUC) and suitable optimal cutoff values for both the GNRI and MNA.

    RESULTS: According to the SGA, MNA, and GNRI, 26.9%, 42.5%, and 44.0% of the participants were malnourished, respectively. The sensitivity, specificity, PPV, and NPV for the GNRI were 0.622, 0.977, 0.982, and 0.558, respectively, while those for the MNA were 0.611, 0.909, 0.932, and 0.533, respectively. The AUC of the GNRI was comparable to that of the MNA (0.831 and 0.898, respectively). Moreover, the optimal malnutrition cutoff value for the GNRI was 94.95.

    CONCLUSIONS: The prevalence of malnutrition remains high among hospitalized elderly patients. Validity of the GNRI is comparable to that of the MNA, and use of the GNRI to assess the nutritional status of this group is proposed with the new suggested cutoff value (GNRI ≤ 94.95), as it is simpler and more efficient. Underdiagnosis of malnutrition can be prevented, possibly reducing the prevalence of malnourished hospitalized elderly patients and improving the quality of the nutritional care process practiced in Malaysia.

    Matched MeSH terms: Sensitivity and Specificity
  6. Abd Rahim MA, Johani FH, Shah SA, Hassan MR, Abdul Manaf MR
    Ann Glob Health, 2019 Jul 24;85(1).
    PMID: 31348624
    BACKGROUND: Helicobacter pylori (H. pylori) infection is known to be associated with peptic ulcer and gastric cancer. Detection of H. pylori infection is a significant part of peptic ulcer and gastric cancer prevention and management. 13C-urea breath test (UBT) provides a good option for the pathogen detection due to its accuracy and safety.

    OBJECTIVE: This review aims to evaluate the 13C-UBT diagnostic accuracy studies conducted among Asian population and validate its use for the Asian population.

    METHODS: Original articles were systematically searched in PubMed, Scopus, and Google Scholar using the PICOS strategy by applying relevant keywords. Only studies published in English and conducted in Asia were included. Our search returned 276 articles. After assessment, 11 articles which answered our research question and met the criteria set for systematic review and meta-analysis were accepted. A total of 15 study protocols were extracted from the 11 accepted articles.

    FINDINGS: Majority of the studies were conducted in Hong Kong (six), followed by Taiwan (five), Japan (two), and one each in Singapore and Israel. All studies had used histology as part of its gold standard of reference. All but one study was performed on adult populations. The summary estimate for sensitivity was 97% (95% CI: 96, 98%), and specificity was 96% (95% CI: 95, 97%), with significant heterogeneity between studies. Adjusting for the dose (50 mg) and breath sample collection time (20 minutes) had improved both accuracy estimates and significantly reduced heterogeneity.

    CONCLUSION: This review supports the test-and-treat strategy for H. pylori infection management. Prevalence and cost-effectiveness studies are mandatory for health authorities to adopt this strategy into national policy.

    Matched MeSH terms: Sensitivity and Specificity
  7. Abd Razak MA, Ahmad NA, Chan YY, Mohamad Kasim N, Yusof M, Abdul Ghani MKA, et al.
    Public Health, 2019 Apr;169:84-92.
    PMID: 30826688 DOI: 10.1016/j.puhe.2019.01.001
    OBJECTIVES: This systematic review aims to provide updated and comprehensive evidence on the validity and feasibility of screening tools for mild cognitive impairment (MCI) and dementia among the elderly at primary healthcare level.

    STUDY DESIGN: A review of articles was performed.

    METHODS: A search strategy was used by using electronic bibliographic databases including PubMed, Embase and CENTRAL for published studies and reference list of published studies. The articles were exported to a bibliographic database for further screening process. Two reviewers worked independently to screen results and extract data from the included studies. Any discrepancies were resolved and confirmed by the consensus of all authors.

    RESULTS: There were three screening approaches for detecting MCI and dementia - screening by a healthcare provider, screening by a self-administered questionnaire and caretaker informant screening. Montreal Cognitive Assessment (MoCA) was the most common and preferable tool for MCI screening (sensitivity [Sn]: 81-97%; specificity [Sp]: 60-86%), whereas Addenbrooke's Cognitive Examination (ACE) was the preferable tool for dementia screening (Sn: 79-100%; Sp: 86%).

    CONCLUSION: This systematic review found that there are three screening approaches for detecting early dementia and MCI at primary health care. ACE and MoCA are recommended tools for screening of dementia and MCI, respectively.

    Matched MeSH terms: Sensitivity and Specificity
  8. Abdul Kadir A, Nordin R, Ismail SB, Yaacob MJ, Wan Mustapha WMR
    Asia Pac Fam Med, 2004;3(1&2):9-18.
    Aim. Validation of the Malay version of the Edinburgh Postnatal Depression Scale (EPDS)
    Methods. A validation study was done involving 52 mothers who were at 4-12 weeks post-delivery. The women completed the Malay versions of EPDS and the 30-item General Health Questionnaire (GHQ). They were then assessed with the Hamilton Depression Rating Scale (HDRS) and Clinical Interview Schedule (CIS). Psychiatric diagnoses were made based on ICD-10 criteria. The validity of EPDS was tested against this clinical diagnosis and the concurrent validity against the Malay version of 30-item GHQ and HDRS scores was also evaluated.
    Results. The best cut-off score of the Malay version of EPDS was 11.5 with the sensitivity of 72.7% and specificity of 92.6 %.
    Conclusion. The Malay version of EPDS is a valid and reliable screening tool for PND.
    Matched MeSH terms: Sensitivity and Specificity
  9. Abdul Rashid SN, Mohamad Saini SB, Abdul Hamid S, Muhammad SJ, Mahmud R, Thali MJ, et al.
    Br J Radiol, 2014 Apr;87(1036):20130472.
    PMID: 24472728 DOI: 10.1259/bjr.20130472
    The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in "drug mules" by plain abdominal digital radiography (DR).
    Matched MeSH terms: Sensitivity and Specificity
  10. Abdulameer SA, Syed Sulaiman SA, Hassali MA, Subramaniam K, Sahib MN
    Osteoporos Int, 2013 Mar;24(3):929-40.
    PMID: 22790611 DOI: 10.1007/s00198-012-2071-1
    In type 2 diabetic patients (T2DM), only 22 % have normal bone mineral density and almost three quarters of the sample population had low self-efficacy towards osteoporosis. These results reflect the need for screening and educational programs to increase the awareness of T2DM towards osteoporosis.
    INTRODUCTION: Our aim was to translate and examine the psychometric properties of the Malay version of the osteoporosis self-efficacy scale (OSES-M) among T2DM and to determine the best cut-off value with optimum sensitivity and specificity. In addition, to assess factors that affects diabetic patients' osteoporosis self-efficacy.
    METHODS: A standard "forward-backward" procedure was used to translate the OSES into Malay language, which was then validated with a convenience sample of 250 T2DM. The sensitivity and specificity of the OSES-M was calculated using receiver operating characteristic curve analysis. Bivariate and multivariate approaches were used to examine multiple independent variables on each dependent variable.
    RESULTS: The mean score of OSES-M was 731.74 ± 197.15. Fleiss' kappa, content validity ratio range, and content validity index were 0.99, 0.75-1, and 0.96, respectively. Two factors were extracted from exploratory factor analysis and were confirmed through confirmatory factor analysis. Internal consistency and test-retest reliability were 0.92 and 0.86, respectively. The optimum cut-off point of OSES-M to predict osteoporosis/osteopenia was 858. Regression analysis revealed that knowledge, health belief, and some demographic data had an impact on OSES-M.
    CONCLUSIONS: The results show that the OSES-M is a reliable and valid instrument for measuring osteoporosis self-efficacy in the Malaysian clinical setting.
    Matched MeSH terms: Sensitivity and Specificity
  11. Abdulameer SA, Syed Sulaiman SA, Hassali MA, Subramaniam K, Sahib MN
    J Community Health, 2013 Feb;38(1):95-105.
    PMID: 22772955 DOI: 10.1007/s10900-012-9586-4
    Osteoporosis is a major growing public health problem and it is clear that much needs to be done to bridge the gap between patients and practitioners. However, the educator must have a valid and reliable tool to evaluate the effectiveness of the teaching and learning that are done. Osteoporosis Knowledge Tool (OKT) provides an important strategy for healthcare professionals to start early intervention for patients who are at risk of osteoporosis. The aims of this study were to translate and examine the psychometric properties of the Malaysian version of the Osteoporosis Knowledge Tool (OKT-M) among 250 type 2 diabetes patients and to assess factors that affect diabetic patients' osteoporosis knowledge. The OKT English version was translated and validated using the internationally accepted and recommended methodology. The sensitivity and specificity of OKT-M was calculated using receiver operating characteristic curve analysis. The face and content validity showed acceptable results. Internal consistency, test-retest reliability, mean difficulty factor and discriminatory power values were 0.72, 0.83, 0.47 ± 0.16 and 0.96, respectively. The cut-off point of the OKT-M to predict osteoporosis/osteopenia was 14 with optimal sensitivity (84.1%) and specificity (85.5%). Regression analysis revealed that health belief, self-efficacy and some demographic data had an impact on the OKT-M. The findings of this validation study indicate that the OKT-M is a reliable and valid tool with good psychometric properties in the Malaysian setting. The OKT-M is an appropriate tool for application in clinical setting to identify patients need for a bone health-promoting intervention regarding lifestyle behaviour changes.
    Matched MeSH terms: Sensitivity and Specificity
  12. Abdulamir AS, Hafidh RR, Abu Bakar F, Abbas K
    Am J Otolaryngol, 2010 Nov-Dec;31(6):410-7.
    PMID: 20015794 DOI: 10.1016/j.amjoto.2009.06.006
    PURPOSE: This study was designed to find a reliable Epstein-Barr virus (EBV) immunoglobulin (Ig) G-based diagnostic/screening test for nasopharyngeal carcinoma (NPC) able to demarcate between the NPC-related seropositivity of EBV IgG antibodies and that of other head and neck cancer (HNCA) and control groups. The NPC-associated immunosuppression affects EBV IgA much more than IgG, leading to inconsistent detection of NPC using EBV IgA antibodies.
    MATERIALS AND METHODS: One hundred twenty-two HNCA patients, 42 NPC, 66 laryngeal carcinoma, and 14 hypopharyngeal carcinoma and 3 groups of 100 control subjects were enrolled in this study. Enzyme-linked immunosorbent assay (ELISA) was used to find a specific cutoff value for the NPC-related seropositivity of EBV IgG antibodies.
    RESULTS: NPC group showed higher serum level of EBV IgG antibodies than control and other HNCA groups (P < .05). However, the traditional cutoff value, mean + 2 SDs of control subjects, failed to demarcate the seropositives of NPC patients from those of healthy population (P > .05). The new cutoff value, mean + 2 SDs of the seropositives group of control subjects who had already been grouped by the traditional cutoff value, proved successful. It succeeded to demarcate between the NPC-related EBV IgG seropositivity and that issued from the persistent, latent, or reactivated EBV infection in the population (P < .05). The sensitivity/specificity of NPC detection by the new cutoff-based ELISA kit, 76.19% and 86%, was close or higher than that of EBV IgA antibodies.
    CONCLUSION: EBV IgG-based ELISA could be used for the diagnosis of NPC using a new cutoff threshold that excludes the population baseline of EBV IgG seropositivity.
    Matched MeSH terms: Sensitivity and Specificity
  13. Abdull Razis AF, Ibrahim MD, Kntayya SB
    Asian Pac J Cancer Prev, 2014;15(20):8571-6.
    PMID: 25374169
    Phytomedicines are believed to have benefits over conventional drugs and are regaining interest in current research. Moringa oleifera is a multi-purpose herbal plant used as human food and an alternative for medicinal purposes worldwide. It has been identified by researchers as a plant with numerous health benefits including nutritional and medicinal advantages. Moringa oleifera contains essential amino acids, carotenoids in leaves, and components with nutraceutical properties, supporting the idea of using this plant as a nutritional supplement or constituent in food preparation. Some nutritional evaluation has been carried out in leaves and stem. An important factor that accounts for the medicinal uses of Moringa oleifera is its very wide range of vital antioxidants, antibiotics and nutrients including vitamins and minerals. Almost all parts from Moringa can be used as a source for nutrition with other useful values. This mini-review elaborate on details its health benefits.
    Matched MeSH terms: Sensitivity and Specificity
  14. Abdullah A, Long CW, Saim L, Mukari SZM
    Med J Malaysia, 2005 Mar;60(1):21-7.
    PMID: 16250276 MyJurnal
    Early identification and management of hearing impairment is very valuable. The goal standard measurement of hearing loss is by brainstem evoked response (BSER). This prospective study was conducted in Hospital University Kebangsaan Malaysia (HUKM) to determine the sensitivity and specificity of transient evoked otoacoustic emission (TEOAE) as a screening tool for hearing impairment from February 1999 to February 2000. One hundred and thirty-three newborns from postnatal ward and seventy-eight newborns from neonatal intensive care unit (NICU) were screened for possible hearing loss using portable TEOAE. This study showed that TEOAE is a very sensitive but moderately specific screening tool.
    Matched MeSH terms: Sensitivity and Specificity
  15. Abdullah A, Mahmud MR, Maimunah A, Zulfiqar MA, Saim L, Mazlan R
    Ann Acad Med Singap, 2003 Jul;32(4):442-5.
    PMID: 12968546
    INTRODUCTION: Accurate preoperative imaging of the temporal bone in patients receiving cochlear implants is important. High resolution computed tomography (HRCT) and magnetic resonance (MR) imaging are the 2 preoperative imaging modalities that provide critical information on abnormalities of the otic capsule, pneumatisation of the mastoid, middle ear abnormalities, cochlear ducts patency and presence of cochlear nerve.

    MATERIALS AND METHODS: The HRCT and MR imaging in 46 cochlear implant patients in our department were reviewed.

    RESULTS: Majority of our patients [34 patients (73.9%)] showed normal HRCT of the temporal bone; 5 (10.9%) patients had labyrinthitis ossificans, 2 (4.3%) had Mondini's abnormality and 2 (4.3%) had middle ear effusion. One patient each had high jugular bulb, hypoplasia of the internal auditory canal and single cochlear cavity, respectively.

    CONCLUSION: The above findings contribute significantly to our surgical decisions regarding candidacy for surgery, side selection and surgical technique in cochlear implantation.

    Matched MeSH terms: Sensitivity and Specificity
  16. Abdullah BJ, Kaur H, Ng KH
    Br J Radiol, 1998 Sep;71(849):930-3.
    PMID: 10195007
    Dried fish bones from eight species of Malaysian fish were placed in an animal cadaver at four sites (tonsil, valleculae, larynx and oesophagus) and radiographed using a double and a single film-screen combination. The use of the single film-screen combination resulted in visibility of all fish bones placed in the larynx, two of which were not visible on the double film-screen combination. There was a 50% increase of the visibility of the fish bones in the oesophagus using the single film-screen combination. The difference in dose and cost between the two different film-screen combinations was not significant.
    Matched MeSH terms: Sensitivity and Specificity
  17. Abdullah J, Saffie N, Sjasri FA, Husin A, Abdul-Rahman Z, Ismail A, et al.
    Braz J Microbiol, 2014;45(4):1385-91.
    PMID: 25763045
    An in-house loop-mediated isothermal amplification (LAMP) reaction was established and evaluated for sensitivity and specificity in detecting the presence of Salmonella Typhi (S. Typhi) isolates from Kelantan, Malaysia. Three sets of primers consisting of two outer and 4 inner were designed based on locus STBHUCCB_38510 of chaperone PapD of S. Typhi genes. The reaction was optimised using genomic DNA of S. Typhi ATCC7251 as the template. The products were visualised directly by colour changes of the reaction. Positive results were indicated by green fluorescence and negative by orange colour. The test was further evaluated for specificity, sensitivity and application on field samples. The results were compared with those obtained by gold standard culture method and Polymerase Chain Reaction (PCR). This method was highly specific and -10 times more sensitive in detecting S. Typhi compared to the optimised conventional polymerase chain reaction (PCR) method.
    Matched MeSH terms: Sensitivity and Specificity
  18. Abdullah J, Ahmad M, Heng LY, Karuppiah N, Sidek H
    Anal Bioanal Chem, 2006 Nov;386(5):1285-92.
    PMID: 17031625
    The stacked-film immobilization of 3-methyl-2-benzothiazolinone hydrazone (MBTH) in hybrid nafion/sol-gel silicate film and horseradish peroxidase (HRP) in chitosan, performed in order to allow the determination of phenolic compounds, was investigated via an optical method. The stacked films were deposited onto a microscope glass slide by a spin-coating technique. The quinone or free radical product formed by the enzymatic reactions of phenolic compounds interacts with MBTH to form azo-dye products, which can be measured spectrophotometrically at a wavelength of 500 nm. The color intensity of the product was found to increase in proportion to the phenolic concentration after 5 min of exposure. The response of the biosensor was linear over concentration ranges of 0.025-0.500, 0.010-0.070 and 0.050-0.300 mM for guaiacol, resorcinol and o-cresol, respectively, and gave detection limits of 0.010, 0.005 and 0.012 mM. The sensor exhibited good sensitivity and stability for at least two months.
    Matched MeSH terms: Sensitivity and Specificity
  19. Abdullah J, Zamzuri I, Awang S, Sayuthi S, Ghani A, Tahir A, et al.
    Acta Neurochir. Suppl., 2005;95:311-4.
    PMID: 16463872
    The monitoring of craniospinal compliance is uncommonly used clinically despite it's value. The Spiegelberg compliance monitor calculates intracranial compliance (C = deltaV/deltaP) from a moving average of small ICP perturbations (deltaP) resulting from a sequence of up to 200 pulses of added volume (deltaV = 0.1 ml, total V = 0.2 ml) made into a double lumen intraventricular balloon catheter. The objective of this study was thus to determine the effectiveness of the decompressive craniectomy done on the worst brain site with regard to compliance (Cl), pressure volume index (PVI), jugular oximetry (SjVo2), autoregulation abnormalties, brain tissue oxygen (TiO2) and cerebral blood flow (CBF). This is a prospective cohort study of 17 patients who were enrolled after consent and approval of the ethics committee between the beginning of the year 2001 and end of the year 2002. For pre and post assessment on compliance and PVI, all 12 patients who survived were reported to become normal after decompressive craniectomy. There is no significant association between pre and post craniectomy assessment in jugular oxymetry (p > 0.05), autoregulation (p > 0.05), intracranial brain oxymetry (p = 0.125) and cerebral blood flow (p = 0.375). Compliance and PVI improved dramatically in all alive patients who received decompressive craniectomy. Compliance and PVI monitoring may be crucial in improving the outcome of severe head injured patients after decompressive craniectomy.
    Matched MeSH terms: Sensitivity and Specificity
  20. Abdullah MZ, Yin W, Bilal M, Armitage DW, Mackin R, Peyton AJ
    Rev Sci Instrum, 2007 Aug;78(8):084703.
    PMID: 17764343
    This article addresses time-domain ultrawide band (UWB) electromagnetic tomography for reconstructing the unknown spatial characteristic of an object from observations of the arrivals of short electromagnetic (EM) pulses. Here, the determination of the first peak arrival of the EM traces constitutes the forward problem, and the inverse problem aims to reconstruct the EM property distribution of the media. In this article, the finite-difference time-domain method implementing a perfectly matched layer is used to solve the forward problem from which the system sensitivity maps are determined. Image reconstruction is based on the combination of a linearized update and regularized Landweber minimization algorithm. Experimental data from a laboratory UWB system using targets of different contrasts, sizes, and shapes in an aqueous media are presented. The results show that this technique can accurately detect and locate unknown targets in spite of the presence of significant levels of noise in the data.
    Matched MeSH terms: Sensitivity and Specificity
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