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Fulltext Biotin-Streptavidin Competition Mediates Sensitive Detection of Biomolecules in Enzyme Linked Immunosorbent Assay

Lakshmipriya T, Gopinath SC, Tang TH

PLoS One, 2016;11(3):e0151153.
PMID: 26954237 DOI: 10.1371/journal.pone.0151153

Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors.

Matched MeSH terms: Sensitivity and Specificity
The sensitivity, specificity and predictive values of post mortem computed tomography in detecting liver and splenic injury due to road traffic accident

Norzailin AB, Noor Azman S, Mohd Helmee MN, Khairul Anuar Z

Med J Malaysia, 2016 02;71(1):1-7.
PMID: 27130735

OBJECTIVE: The purpose of the study was to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of post mortem computed tomography (PMCT) in detecting liver and splenic injuries due to road traffic accidents.
MATERIAL & METHOD: 61 road traffic accidental death cases underwent both PMCT and conventional autopsy. The imaging findings were compared to the conventional autopsy findings.
RESULT: The sensitivity, specificity, PPV and NPV for liver injuries in PMCT was 71%, 82%, 68% and 85% while that of splenic injuries was 73%, 80%, 55% and 90% respectively. The accuracy of PMCT scan was 79% for both liver and splenic injuries. There is strong association between lower left ribs fracture and splenic injury (p=0.005) and significant association between positive liver and splenic PMCT finding and intraabdominal fatal injury (p=0.037).
CONCLUSION: In conclusion PMCT has high specificity and NPV for liver and splenic injuries; however the sensitivity and PPV are low. The overall accuracy is not high enough to enable PMCT to be used as a replacement for conventional autopsy; however it is a useful complementary examination and has potential to be used as decision making tool for selective internal autopsy.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Comparison of Abtectcell III and Diamed red cell antibody screening kit for detection of clinically significant red cells alloantibody

Syed Azim SM, Muhamad NA, Leong CF, Hussin NH

Malays J Pathol, 2015 Aug;37(2):109-14.
PMID: 26277667 MyJurnal

Antibody screening is important for the antenatal screening and pre-transfusion tests. This study aimed to compare the MUT/Mur kodecytesAbtectcell III (CSL Abtectcell III) red cell antibody screening kit with DiaMed ID-Dia Cell I-II-III Asia that was then used in our laboratory. In this study, 125 samples were randomly chosen, with 67 samples of known antibody specificities and 58 samples identified as negative for antibody, as the negative control. Concordant negative results were obtained in 57 out of 58 antibody negative samples. Concordant antibody positive results with both reagents were seen in 49 out of 67 samples. There were 18 discrepant results of antibody screening with CSL Abtetcell III (16/18 for vMNS antibodies). The sensitivity and specificity for CSL Abtectcell III were 73.0% and 98.3% respectively. In conclusion, the CSL Abtectcell III reagent would be an acceptable alternative for screening of red cell alloantibodies. It was able to detect all the clinically significant alloantibodies.

Matched MeSH terms: Sensitivity and Specificity
Fine needle aspiration cytology of the thyroid--a review of experience in 1853 cases

Jayaram G, Razak A, Gan SK, Alhady SF

Malays J Pathol, 1999 Jun;21(1):17-27.
PMID: 10879275

1853 thyroid lesions subjected to cytological sampling (either by the fine needle aspiration or fine needle capillary sampling technique) from January 1992 to December 1997 at the University Hospital, Kuala Lumpur, were reviewed. Nodular goitre was the most common thyroid lesion needled (67.35%). Among the neoplastic lesions, follicular neoplasms predominated (64%), followed by papillary carcinoma (29.4%). In 325 cases, partial or total thyroidectomy had been done, providing material for histological review and cyto-histological correlation. Cytological diagnosis was found to have high sensitivity and specificity rates of over 75%. Besides, most non-neoplastic thyroid lesions could be diagnosed on cytology. The scope of cytology in the diagnosis of lymphomas, anaplastic and metastatic tumours rendered diagnostic biopsies (or thyroidectomy) unnecessary in these cases. Being a cost-effective technique and having the capacity to provide exact morphological diagnosis in a large variety of thyroid lesions, cytology is obviously the method of choice in the assessment of thyroid nodules.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Beck Depression Inventory (BDI): a reliability and validity test in the Malaysian urological population

Quek KF, Low WY, Razack AH, Loh CS

Med J Malaysia, 2001 Sep;56(3):285-92.
PMID: 11732072

This study aimed to validate the Beck Depression Inventory (BDI) in the Malaysian urological population. Reliability and internal consistency were evaluated using the test-retest method and internal consistency was assessed using Cronbach's alpha. Responsiveness was expressed as the effect size. Internal consistency was high (Cronbach's alpha value = 0.56 to 0.87). Test-retest correlation coefficient and intraclass correlation coefficient were significant (ICC = 0.56 to 0.87) and a high degree of sensitivity and specificity. The BDI is thus a reliable and a valid instrument to be used in Malaysia.

Matched MeSH terms: Sensitivity and Specificity
Prevalence of latex allergy may be vastly overestimated when determined by in vitro assays

Yeang HY

Ann. Allergy Asthma Immunol., 2000 Jun;84(6):628-32.
PMID: 10875493 DOI: 10.1016/S1081-1206(10)62415-5

BACKGROUND:
The prevalence of latex-specific IgE computed from the results of serologic assays is commonly thought to reflect, to a greater or lesser extent, the prevalence of latex allergy and its implied risk.

OBJECTIVE:
The study examines how imperfect test specificity of in vitro assays influences the precision of latex allergy prevalence that it estimates.

METHODS:
Various models encompassing a range of hypothetical test sensitivity and specificity values are investigated to gauge their influence on the estimate of latex allergy prevalence. The models examine these interactions in situations of high or low allergy prevalence.

RESULTS:
Serologic latex diagnostic assays with test specificity within the range of those of commercially available assays can greatly overestimate prevalence where the true prevalence is low (eg, of the order of one in 100 or one in 1,000). A formula to correct for errors in prevalence estimates arising from imperfect test sensitivity and specificity of an in vitro assay is presented.

CONCLUSION:
While serologic assays for latex IgE pose few hazards to the patient and are useful for confirming the diagnosis of latex allergy, the test results may vastly overestimate the true prevalence of latex allergy and its associated risks in situations where latex allergy is actually rare.

Matched MeSH terms: Sensitivity and Specificity
Determination of polymorphic forms of ranitidine-HCl by DRIFTS and XRPD

Agatonovic-Kustrin S, Rades T, Wu V, Saville D, Tucker IG

J Pharm Biomed Anal, 2001 Jul;25(5-6):741-50.
PMID: 11377056

The identification, characterization and quantification of crystal forms are becoming increasingly important within the pharmaceutical industry. A combination of different physical analytical techniques is usually necessary for this task. In this work solid-state techniques, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray powder diffractometry (XRPD) were combined to analyze polymorphic purity of crystalline ranitidine-HCl, an antiulcer drug, H2 receptor antagonists. A series of 12 different mixtures of Form 1 and 2 was prepared by geometric mixing and their DRIFT spectra and XRD powder patterns were obtained and analyzed, either alone or combined together, using Artificial Neural Networks (ANNs). A standard feed-forward network, with back-propagation rule and with multi layer perceptron architecture (MPL) was chosen. A working range of 1.0-100% (w/w) of crystal Form 2 in Form 1 was established with a minimum quantifiable level (MQL) of 5.2% and limit of detection of 1.5% (w/w). The results demonstrate that DRIFTS combined with XRPD may be successfully used to distinguish between the ranitidine-HCl polymorphs and to quantify the composition of binary mixtures of the two.

Matched MeSH terms: Sensitivity and Specificity
Detection of rickettsial antibodies using Weil-Felix (OXK and OX19) antigens and the indirect immunoperoxidase assay

Tay ST, Kamalanathan M, Rohani MY

Southeast Asian J. Trop. Med. Public Health, 2003 Mar;34(1):171-4.
PMID: 12971531
Matched MeSH terms: Sensitivity and Specificity
Quantitative application of fecal sterols using gas chromatography-mass spectrometry to investigate fecal pollution in tropical waters: western Malaysia and Mekong Delta, Vietnam

Isobe KO, Tarao M, Zakaria MP, Chiem NH, Minh le Y, Takada H

Environ Sci Technol, 2002 Nov 1;36(21):4497-507.
PMID: 12433157

This is the first report on fecal pollution using molecular markers in Southeast Asia where serious sewage pollution has occurred. A simple and sensitive analytical method using gas chromatography-mass spectrometry for 10 sterols in various environmental samples was developed to monitor extensive areas of tropical Asia. First, the method was applied to wastewater to confirm that >95% of sterols existed in the particulate phase. Then the approach was applied to a tropical Asian region, Malaysia and Vietnam, with a selection of 59 sampling stations in total. River water and sediment samples were collected and analyzed for chemical markers (coprostanol and other sterols) and microbiological markers (fecal coliforms and fecal streptococci). Particulate coprostanol concentrations ranged from <0.0001 to 13.47 microg/L in tropical river and estuarine waters, indicating severe fecal pollution in populous areas. Coprostanol concentrations in the sediments ranged from 0.005 to 15.5 microg/g-dry. The sedimentary coprostanol concentrations were lower than those reported in some urban areas of industrialized countries. This is probably because frequent heavy rain induces intensive input of eroded soil, which dilutes fecal material in river sediments. The relationship between the concentrations of fecal sterols and bacterial indicators was examined in an attempt to develop public health criteria for coprostanol levels applicable to the tropical region. Coprostanol concentrations of 30-100 ng/L or percent coprostanol levels of 2% corresponded to approximately 1000 fecal coliforms per 100 mL, which is set for secondary contact limit in many countries. These coprostanol concentrations were lower than those proposed as criteria in temperate countries, probably owing to greater survival of bacteria in warmer tropical waters. On the basis of these criteria, extensive monitoring of sediments suggests that poor sanitary conditions exist in most of the urbanized area of Malaysia and in several urban and rural sites in Vietnam.

Matched MeSH terms: Sensitivity and Specificity
Fulltext 14C-urea breath test: a useful non-invasive test in the diagnosis of Helicobacter pylori infection

Goh KL, Parasakthi N, Peh SC, Ong KK

Med J Malaysia, 1995 Sep;50(3):208-11.
PMID: 8926896

Sixty-three breath samples were collected from patients who underwent a 14C-urea breath test. Following ingestion of a radiolabelled 14C-labelled urea solution, breath samples containing 14C-labelled carbon dioxide were trapped in a solution containing hyamine hydroxide. Samples were then counted in a liquid scintillation counter. Breath samples were collected at 2, 15, 20, 25 and 30 minutes following ingestion of the urea solution. The presence or absence of Helicobacter pylori (HP) infection was determined on the basis of endoscopic biopsy tests which included culture, histological examination, rapid urease test and a gram stain of a fresh tissue smear. Thirty-two HP positive and 31 HP negative samples were collected. The mean counts at 15, 20, 12 and 30 minutes time points were: 4413, 4458, 4109 and 3795 dpm respectively for the positive samples and 1275, 877, 690 and 565 dpm respectively for the negative samples. Based on a cutoff value (mean of the negative samples + 3 standard deviations) for every time point, HP positive and negative samples could be clearly differentiated giving a sensitivity and specificity of 100%. The 14C-urea breath test is a reliable and convenient diagnostic test for H. pylori.

Matched MeSH terms: Sensitivity and Specificity
The role of transvaginal sonography in the diagnosis of placenta praevia

Tan NH, Abu M, Woo JL, Tahir HM

Aust N Z J Obstet Gynaecol, 1995 Feb;35(1):42-5.
PMID: 7771998 DOI: 10.1111/j.1479-828x.1995.tb01828.x

Transvaginal sonography was performed in 70 patients diagnosed to have placenta praevia by transabdominal sonography. The diagnosis was confirmed either by digital examination in theatre at term or operative finding at delivery. Forty-nine cases (70%) were correctly diagnosed to have placenta praevia by both modes of sonography. Transvaginal sonography ruled out placenta praevia in 12 cases (17%) thought to be placenta praevia by transabdominal ultrasound. Both transabdominal and transvaginal sonography demonstrated 'placental migration' in 4 cases (6%) which were no longer praevia at delivery. Five patients (7%) were erroneously believed to have placenta praevia by both sonographic techniques. Overall, the diagnostic accuracy of transvaginal sonography was 92.8% compared with 75.7% for transabdominal sonography. None of the subjects experienced any exacerbation of bleeding or other complications. The results suggest that transvaginal sonographic localization of the placenta is safe and superior to the transabdominal route.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Diagnosis of malaria by enzymatic detection of polymerase chain reaction products

Normaznah Y, Furuta T, Saniah K, Noor Rain A, Kojima S, Mak JW

Southeast Asian J. Trop. Med. Public Health, 1997 Jun;28(2):432-3.
PMID: 9444035
Matched MeSH terms: Sensitivity and Specificity
Development of a slide latex agglutination test for rotavirus antigen detection

Yap KL

Malays J Pathol, 1994 Jun;16(1):49-56.
PMID: 16329576

The aim of this study was to optimize the conditions for the passive adsorption of polyclonal antibody onto plain surface polystyrene latex particles and its performance in a slide latex agglutination test for rotavirus antigen detection. Cleaning of latex particles by washing through repetitive centrifuging, decanting and resuspending in distilled water was adequate in removing surfactants from the particles' surfaces to enable coating. A study of antibody concentration, incubation temperature and buffer pH revealed that optimum coating was achieved with a 3-fold excess of antibody to the calculated total particle surface capacity for the antibody in a glycine-saline buffer of pH 9.2 at 40 degrees C for 4 hours. The ionic strength and pH of the latex suspending buffer and the sample buffer were critical factors determining the sensitivity of the test and the appearance of non-specific agglutination. Ultrasonication, addition of glycerol and Tween 20, either individually or in combination, were able to suppress non-specific agglutination in some batches of latex reagents. Polyethylene glycol 6000 enhanced the quality of agglutination as well as reduced the time of its appearance, especially in reagents that produced poor agglutination.

Matched MeSH terms: Sensitivity and Specificity
Fulltext The value of positive nitrites in screening asymptomatic bacteriuria amongst Malaysian school children

Zainal D, Baba A

Southeast Asian J. Trop. Med. Public Health, 1996 Mar;27(1):184-8.
PMID: 9031425

It is important to diagnose and treat urinary tract infection in children before renal damage has taken place. Hence a new screening procedure will be of interest. This study was conducted to evaluate the efficacy of urinary nitrite in screening for asymptomatic bacteriuria among school children compared to a more traditional method. Of the 44,816 school children investigated 240 (0.54%) students were judged to have bacteriuria ie 82 (0.19%) in boys and 158 (0.35%) in girls. Escherichia coli was the commonest organism isolated (28.75%). Urine dipstick testing for nitrite was found to have a low sensitivity and positive predictive value. While urinalysis for pyuria was noted to have a sensitivity of 77.9%, a specificity of 95.8% and a negative predictive value of 99.9%.

Matched MeSH terms: Sensitivity and Specificity
An in-house enzyme-linked immunoabsorbant assay for human growth hormone

Nazaimoon W, Ng ML, Bak K

Malays J Pathol, 1993 Jun;15(1):75-83.
PMID: 8277795

A simple, non-isotopic in-house enzyme-linked immunoabsorbant assay (ELISA) for human growth hormone (GH) was developed. The assay involved using in-house polyclonal anti-GH adsorbed onto 96-well microtitre plates, commercially prepared mouse monoclonal anti-GH, and goat anti-mouse IgG horseradish peroxidase detection system. Results of recovery and parallelism studies ranged from 95%-106% and 98%-101% respectively, of the expected values. The detection limit of the assay was 0.008 mIU/well or the equivalent to 0.4 mIU/L of undiluted serum. Intra- and interassay coefficients of variations were 4.8%-7.9% and 6.5%-8.7% respectively. Serum GH levels measured in this assay correlated well with those measured in established in-house radioimmunoassays (r = 0.985, p < 0.001) and immunoradiometric assay from NETRIA (r = 0.984, p < 0.001).

Matched MeSH terms: Sensitivity and Specificity
Fulltext Allergic skin tests in Malaysian asthmatics

Ismail Y

Med J Malaysia, 1992 Mar;47(1):69-73.
PMID: 1387454

To assess the prevalence of skin test sensitivity among asthmatic patients in Malaysia, skin prick tests for allergy in 134 adult asthmatic patients and 120 control subjects were done. 90% of asthmatic patients had positive skin test to at least one allergens as compared to 78% of the controls. House dust mite was the most frequent allergen to which the subjects had positive reactions. Sixty-four percent of the asthmatic patients had associated rhinitis. There was no significant difference in the skin test sensitivity between asthmatic patients with associated rhinitis and those without.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Development of ELISA for diagnosis of allergy to Dermatophagoides farinae

Ho TM, Radha K, Shahnaz M, Singaram SP

Med J Malaysia, 1993 Sep;48(3):308-12.
PMID: 8183144

An indirect enzyme linked immunosorbent assay (ELISA) was developed for the diagnosis of allergy to a house dust mite, Dermatophagoides farinae. The efficacy of the ELISA was then evaluated against a prick test using a commercial allergen. Eighty five suspected allergic rhinitis patients from the Otorhinolaryngology Department, Kuala Lumpur General Hospital, were tested with the ELISA and prick test. Prick test and ELISA results were positive in 84.7% and 80.0% of the patients respectively. The ELISA was found to have 87.5% sensitivity, 61.5% specificity, 92.6% positive predictive value, 47.1% negative predictive value, 7.4% false positive and 52.9% false negative. There was total agreement between the prick test and ELISA for prick test grades of 3+ and 4+. It is concluded that the ELISA is a useful assay for detection of individuals who are highly sensitive to D. farinae.

Matched MeSH terms: Sensitivity and Specificity
Fulltext A supersensitive in-house enzyme-linked immunosorbent assay (ELISA) for measurement of thyroid-stimulating hormone (TSH) and its clinical applications

Goh KH, Goh ML, Thean ET, Khalid BA

Med J Malaysia, 1992 Dec;47(4):248-60.
PMID: 1303476

A supersensitive ELISA was developed for measurement of thyroid-stimulating hormone (TSH) concentrations in serum using in-house rabbit polyclonal antisera and a commercial monoclonal antibody. The assay was optimised and validated by recovery, linearity and cross-reactivity experiments and further compared to other available assays and EQAS samples. Good precision was obtained with a working assay range of 0.2 to 100 mIU/L with < 10% coefficient of variation (CV) for both intra and interassay. The assay is highly sensitive and specific with a minimum detectable limit of 0.07 mIU/L and negligible cross-reactivities against LH, FSH, HCG and other pituitary peptides. Good correlations were obtained when compared to Abbott hTSH EIA (r = 0.993; p < 0.001; n = 85) and NETRIA IRMA (r + 0.995; p < 0.001; n = 76). The normal reference range established was 0.4 to 4.0 mIU/L (n = 76). TSH levels in serum of thyrotoxic patients (n = 83) were significantly lower (0.07 to 0.20 mIU/L, p < 0.0001) and completely distinct from normal values thereby obviating the requirement of a TRH-stimulation test. Stability studies showed that coated wells can be stored at 4 degrees C for at least 2 months. This highly sensitive in-house hTSH ELISA which is cheap, stable and readily available is useful for diagnosis and management of patients with various thyroid disorders.

Matched MeSH terms: Sensitivity and Specificity
Fulltext 405 cases of bronchial brushing cytology: an evaluation

Ngen RMY, Cheong I, Yahaya O

Med J Malaysia, 1985 Jun;40(2):98-100.
PMID: 3834293

405 cases of bronchial brushing cytology were evaluated for its effectiveness in detecting pulmonary carcinoma. Cytohistologic findings were correlated whenever endoscopic biopsies were performed. Sputum cytological investigations were also included in this paper to examine the total diagnostic sensitivity of all the three methods combined.

Matched MeSH terms: Sensitivity and Specificity
Fulltext The use of mid-arm circumference for screening malnutrition in preschool children

Ng TKW

Med J Malaysia, 1984 Mar;39(1):28-34.
PMID: 6439983

Correlation analysis of mid-arm circumference (MAC), weight-for-age and weight-for-height obtained from 807 Malay preschool children aged 12-71 months show that MAC had a relatively low correlation with weight-for-age (r = 0.59, P <0.001) and weight-for-height (r = 0.63, P<0.001). MAC percentiles and sensitivity-specificity analysis indicate that when weight-for-age and weight-for-height were used separately to define 'true' malnutrition, MAC was not sensitive enough to detect Malaysian children with only mild to moderate protein-energy malnutrition (PEM). The value of MAC as a screening measure in malnutrition is only limited to identifying the more severe forms of PEM in young children and the present study indicates that a MAC of 13.0-13.7 cm may be used for identifying moderate to severe PEM and under 13.0 cm for severe PEM.

Matched MeSH terms: Sensitivity and Specificity

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