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Improved high-performance liquid chromatographic analysis of terazosin in human plasma

Cheah PY, Yuen KH, Liong ML

J Chromatogr B Biomed Sci Appl, 2000 Aug 18;745(2):439-43.
PMID: 11043762

A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) method was developed for the determination of terazosin in human plasma. The method involves a one-step single solvent extraction procedure using dichloromethane with a 0.25 ml plasma sample. Recovery values were all greater than 90% over the concentration range 0.25-100 ng/ml. Terazosin was found to adsorb to glass or plastic tubes, but this could be circumvented by using disposable plastic tubes. Also, rinsing the injector port with methanol after each injection helped to prevent any carry-over effect. The internal standard, prazosin, did not exhibit this problem. The method has a quantification limit of 0.25 ng/ml. The within- and between-day coefficient of variation and accuracy values were all less than 7% over the concentration range 0.25-100 ng/ml and hence the method is suitable for use in pharmacokinetic studies of terazosin.

Matched MeSH terms: Sensitivity and Specificity
Reliability and validity of the National Institutes of Health: Chronic Prostatitis Symptom Index in a Malaysian population

Cheah PY, Liong ML, Yuen KH, Lee S, Yang JR, Teh CL, et al.

World J Urol, 2006 Feb;24(1):79-87.
PMID: 16465553 DOI: 10.1007/s00345-005-0037-z

The objective of the study is to determine the short- and long-term utility of the Chinese, Malay and English versions of the National Institutes of Health--Chronic Prostatitis Symptom Index (NIH-CPSI) in our ethnically diverse population. The NIH-CPSI was translated into Chinese and Malay, and then verified by back translation into English. Subjects included 100 new chronic prostatitis/chronic pelvic pain (CP/CPPS) patients, 71 new benign prostatic hyperplasia patients and 97 healthy individuals. Reliability was evaluated with test-retest reproducibility (TR) by calculating intraclass correlation coefficients (ICC). Internal consistency was evaluated by calculating Cronbach's alpha (alpha). Validity assessments included discriminant and construct validity. (Presented in the order of Chinese, Malay then English). ICC values for short-term (1 week) TR were 0.90, 0.80 and 0.89, while ICC values for long-term (14 weeks) TR were 0.54, 0.61 and 0.61. Cronbach's alpha values were 0.63, 0.62 and 0.57. The NIH-CPSI total score discriminated CP/CPPS patients (P<0.001) from the control groups with receiver operating curve values of 0.95, 0.98 and 0.94, respectively. Construct validity, reflected by the correlation coefficient values between the International Prostate Symptom Score and the NIH-CPSI of CP/CPPS patients were 0.72, 0.49 and 0.63 (all P<0.05). The Chinese, Malay and English versions of the NIH-CPSI each proved effective in our population. Short-term TR and discriminant validity were excellent for all three versions. However, long-term TR was only moderate, which might reflect variation in patients' perceptions of symptoms over time.

Matched MeSH terms: Sensitivity and Specificity
Validation of an informant-based cognitive screening tool for Parkinson disease

Chee KY, Ong KY, Mak CY, Yacob S, Yeo SC, Thrichelam N, et al.

Asia Pac Psychiatry, 2017 Dec;9(4).
PMID: 28326670 DOI: 10.1111/appy.12278

INTRODUCTION: The objective of this study was to establish the psychometric properties of the AD8 Dementia Screening Interview in patients with Parkinson disease (PD) with or without cognitive impairment using the Montreal Cognitive Assessment Tool (MoCA) for comparison.
METHODS: The AD8 was translated into Malay for Malay-speaking participants. A correlation analysis and a receiver operator characteristic curve were generated to establish the psychometric properties of the AD8 in relation to the MoCA.
RESULTS: One hundred fifty patients and their caretakers completed the AD8 and MoCA. Using a cutoff score of 1/8, the AD8 had 81% sensitivity and 59% specificity for the detection of cognitive impairment in PD. With a cutoff score of 2/8, the AD8 had 83% specificity and 64% sensitivity. The area under the receiver operator characteristic curve was 80%, indicating good-to-excellent discriminative ability.
DISCUSSION: These findings suggest that the AD8 can reliably differentiate between cognitively impaired and cognitively normal patients with PD and is a useful caregiver screening tool for PD.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Clarifying the debate on population-based screening for breast cancer with mammography: A systematic review of randomized controlled trials on mammography with Bayesian meta-analysis and causal model

Chen TH, Yen AM, Fann JC, Gordon P, Chen SL, Chiu SY, et al.

Medicine (Baltimore), 2017 Jan;96(3):e5684.
PMID: 28099330 DOI: 10.1097/MD.0000000000005684

BACKGROUND: The recent controversy about using mammography to screen for breast cancer based on randomized controlled trials over 3 decades in Western countries has not only eclipsed the paradigm of evidence-based medicine, but also puts health decision-makers in countries where breast cancer screening is still being considered in a dilemma to adopt or abandon such a well-established screening modality.
METHODS: We reanalyzed the empirical data from the Health Insurance Plan trial in 1963 to the UK age trial in 1991 and their follow-up data published until 2015. We first performed Bayesian conjugated meta-analyses on the heterogeneity of attendance rate, sensitivity, and over-detection and their impacts on advanced stage breast cancer and death from breast cancer across trials using Bayesian Poisson fixed- and random-effect regression model. Bayesian meta-analysis of causal model was then developed to assess a cascade of causal relationships regarding the impact of both attendance and sensitivity on 2 main outcomes.
RESULTS: The causes of heterogeneity responsible for the disparities across the trials were clearly manifested in 3 components. The attendance rate ranged from 61.3% to 90.4%. The sensitivity estimates show substantial variation from 57.26% to 87.97% but improved with time from 64% in 1963 to 82% in 1980 when Bayesian conjugated meta-analysis was conducted in chronological order. The percentage of over-detection shows a wide range from 0% to 28%, adjusting for long lead-time. The impacts of the attendance rate and sensitivity on the 2 main outcomes were statistically significant. Causal inference made by linking these causal relationships with emphasis on the heterogeneity of the attendance rate and sensitivity accounted for the variation in the reduction of advanced breast cancer (none-30%) and of mortality (none-31%). We estimated a 33% (95% CI: 24-42%) and 13% (95% CI: 6-20%) breast cancer mortality reduction for the best scenario (90% attendance rate and 95% sensitivity) and the poor scenario (30% attendance rate and 55% sensitivity), respectively.
CONCLUSION: Elucidating the scenarios from high to low performance and learning from the experiences of these trials helps screening policy-makers contemplate on how to avoid errors made in ineffective studies and emulate the effective studies to save women lives.

Matched MeSH terms: Sensitivity and Specificity
Modeling flood susceptibility using data-driven approaches of naïve Bayes tree, alternating decision tree, and random forest methods

Chen W, Li Y, Xue W, Shahabi H, Li S, Hong H, et al.

Sci Total Environ, 2020 Jan 20;701:134979.
PMID: 31733400 DOI: 10.1016/j.scitotenv.2019.134979

Floods are one of the most devastating types of disasters that cause loss of lives and property worldwide each year. This study aimed to evaluate and compare the prediction capability of the naïve Bayes tree (NBTree), alternating decision tree (ADTree), and random forest (RF) methods for the spatial prediction of flood occurrence in the Quannan area, China. A flood inventory map with 363 flood locations was produced and partitioned into training and validation datasets through random selection with a ratio of 70/30. The spatial flood database was constructed using thirteen flood explanatory factors. The probability certainty factor (PCF) method was used to analyze the correlation between the factors and flood occurrences. Consequently, three flood susceptibility maps were produced using the NBTree, ADTree, and RF methods. Finally, the area under the curve (AUC) and statistical measures were used to validate the flood susceptibility models. The results indicated that the RF method is an efficient and reliable model in flood susceptibility assessment, with the highest AUC values, positive predictive rate, negative predictive rate, sensitivity, specificity, and accuracy for the training (0.951, 0.892, 0.941, 0.945, 0.886, and 0.915, respectively) and validation (0.925, 0.851, 0.938, 0.945, 0.835, and 0.890, respectively) datasets.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Identification of circulating biomarkers in sera of Plasmodium knowlesi-infected malaria patients--comparison against Plasmodium vivax infection

Chen Y, Chan CK, Kerishnan JP, Lau YL, Wong YL, Gopinath SC

BMC Infect Dis, 2015;15:49.
PMID: 25656928 DOI: 10.1186/s12879-015-0786-2

Plasmodium knowlesi was identified as the fifth major malaria parasite in humans. It presents severe clinical symptoms and leads to mortality as a result of hyperparasitemia in a short period of time. This study aimed to improve the current understanding of P. knowlesi and identify potential biomarkers for knowlesi malaria.

Matched MeSH terms: Sensitivity and Specificity
Detection of immunoglobulins M and G using culture filtrate antigen of Burkholderia pseudomallei

Chenthamarakshan V, Vadivelu J, Puthucheary SD

Diagn Microbiol Infect Dis, 2001 Jan;39(1):1-7.
PMID: 11173184

IgM and IgG based ELISA systems were developed using the culture filtrate antigen (CFA) of Burkholderia pseudomallei. The assays were evaluated using 95 sera from 66 septicemic cases and 47 sera from 20 cases with localized melioidosis. In addition 65 sera from culture negative cases that were also serologically negative for other endemic infections clinically suspected of melioidosis were included. These were compared with sera from 260 non-melioidosis cases, 169 sera from individuals with high risk of acquiring the infection and 48 sera from healthy controls. The IgG-ELISA was 96% sensitive and 94% specific. All sera from cases with septicemic and localized infections and 61 of 63 sera from clinically suspected melioidosis cases were positive for IgG antibody. The geometric mean titre index (GMTI) values of IgG antibody in melioidosis cases were significantly higher (p < 0.0005) compared to that of healthy subjects, high risk group and subjects with non-melioidosis infections. The sensitivity and specificity of IgM ELISA was 74 and 99% respectively. The GMTI value of IgM antibody in the sera of melioidosis cases was significantly higher as compared to that of non-melioidosis disease controls (p < or = 0.001). These results demonstrate that the detection of IgG is a better indicator of the disease in the diagnosis of melioidosis.

Matched MeSH terms: Sensitivity and Specificity
Fulltext How useful is a history of rubella vaccination for determination of disease susceptibility? A cross-sectional study at a public funded health clinic in Malaysia

Cheong AT, Tong SF, Khoo EM

BMC Fam Pract, 2013;14:19.
PMID: 23368977 DOI: 10.1186/1471-2296-14-19

Identification of pregnant women susceptible to rubella is important as vaccination can be given postpartum to prevent future risks of congenital rubella syndrome. However, in Malaysia, rubella antibody screening is not offered routinely to pregnant women in public funded health clinics due to cost constraint. Instead, a history of rubella vaccination is asked to be provided to establish the women's risk for rubella infection. The usefulness of this history, however, is not established. Thus, this paper aimed to determine the usefulness of a history of rubella vaccination in determining rubella susceptibility in pregnant women.

Matched MeSH terms: Sensitivity and Specificity
Optimal waist circumference cut-off values for predicting cardiovascular risk factors in a multi-ethnic Malaysian population

Cheong KC, Ghazali SM, Hock LK, Yusoff AF, Selvarajah S, Haniff J, et al.

Obes Res Clin Pract, 2014 Mar-Apr;8(2):e154-62.
PMID: 24743011 DOI: 10.1016/j.orcp.2013.03.004

INTRODUCTION: Previous studies have proposed the lower waist circumference (WC) cutoffs be used for defining abdominal obesity in Asian populations.
OBJECTIVE: To determine the optimal cut-offs of waist circumference (WC) in predicting cardiovascular (CV) risk factors in the multi-ethnic Malaysian population.
METHODS: We analysed data from 32,703 respondents (14,980 men and 17,723 women) aged 18 years and above who participated in the Third National Health and Morbidity Survey in 2006. Gender-specific logistic regression analyses were used to examine associations between WC and three CV risk factors (diabetes mellitus, hypertension, and hypercholesterolemia). The Receiver Operating Characteristic (ROC) curves were used to determine the cut-off values of WC with optimum sensitivity and specificity for detecting these CV risk factors.
RESULTS: The odds ratio for having diabetes mellitus, hypertension, and hypercholesterolemia, or at least one of these risks, increased significantly as the WC cut-off point increased. Optimal WC cut-off values for predicting the presence of diabetes mellitus, hypertension, hypercholesterolemia and at least one of the three CV risk factors varied from 81.4 to 85.5 cm for men and 79.8 to 80.7 cm for women.
CONCLUSIONS: Our findings indicate that WC cut-offs of 81 cm for men and 80 cm for women are appropriate for defining abdominal obesity and for recommendation to undergo cardiovascular risk screening and weight management in the Malaysian adult population.
Study name: National Health and Morbidity Survey (NHMS-2006)

Matched MeSH terms: Sensitivity and Specificity
Fulltext Comparison of methods in the detection of enterotoxigenic Escherichia coli in a Malaysian laboratory

Cheong YM, Jegathesan M, Ansary A, Othman M

Med J Malaysia, 1990 Mar;45(1):42-8.
PMID: 2152068

The prevalence of Enterotoxigenic Escherichia coli (ETEC) in 433 stool samples from diarrhoeal cases of all ages was studied using two commercially available test kits for the detection of heat labile toxin (LT) and the infant mouse assay for the heat stable toxin (ST). 16 samples (3.7%) were positive for ETEC, of which nine were producing ST alone, six LT alone and only one was producing both LT and ST. Although the percentage of isolation rate was low, its occurrence was almost as common as the Shigella spp and Salmonella spp in the same study. Of the two test kits examined, the Phadebact ETEC-LT Test 50 (Pharmacia Diagnostics, Uppsala, Sweden) was found to be more suitable for use in a routine diagnostic laboratory. Ten out of 12 (83%) of the strains tested were resistant to one or more antibiotics.

Matched MeSH terms: Sensitivity and Specificity
Quantitation of green fluorescent protein using a gel-based imaging method

Chew FN, Tan WS, Ling TC, Tan CS, Tey BT

Anal Biochem, 2009 Jan 15;384(2):353-5.
PMID: 18952038 DOI: 10.1016/j.ab.2008.10.010

Green fluorescent protein (GFP) is a versatile reporter protein and has been widely used in biological research. However, its quantitation requires expensive equipment such as a spectrofluorometer. In the current study, a gel documentation imaging system using a native polyacrylamide gel for the quantitation of GFP was developed. The assay was evaluated for its precision, linearity, reproducibility, and sensitivity in the presence of Escherichia coli cells and was compared with the spectrofluorometric method. Using this newly established, gel-based imaging technique; the amount of GFP can be quantified accurately.

Matched MeSH terms: Sensitivity and Specificity
A comparison of brain phantom relative permittivity with CST simulation library and existing research

Chew KM, Seman N, Sudirman R, Yong CY

Biomed Mater Eng, 2014;24(6):2161-7.
PMID: 25226914 DOI: 10.3233/BME-141027

The development of human-like brain phantom is important for data acquisition in microwave imaging. The characteristics of the phantom should be based on the real human body dielectric properties such as relative permittivity. The development of phantom includes the greymatter and whitematter regions, each with a relative permittivity of 38 and 28 respectively at 10 GHz frequency. Results were compared with the value obtained from the standard library of Computer Simulation Technology (CST) simulation application and the existing research by Fernandez and Gabriel. Our experimental results show a positive outcome, in which the proposed mixture was adequate to represent real human brain for data acquisition.

Matched MeSH terms: Sensitivity and Specificity
Real-time polymerase chain reaction for diagnosis and quantitation of negative strand of chikungunya virus

Chiam CW, Chan YF, Loong SK, Yong SS, Hooi PS, Sam IC

Diagn Microbiol Infect Dis, 2013 Oct;77(2):133-7.
PMID: 23886793 DOI: 10.1016/j.diagmicrobio.2013.06.018

Quantitative real-time polymerase chain reaction (qRT-PCR) is useful for diagnosis and studying virus replication. We developed positive- and negative-strand qRT-PCR assays to detect nsP3 of chikungunya virus (CHIKV), a positive-strand RNA alphavirus that causes epidemic fever, rash, and arthritis. The positive- and negative-strand qRT-PCR assays had limits of quantification of 1 and 3 log10 RNA copies/reaction, respectively. Compared to a published E1 diagnostic assay using 30 laboratory-confirmed clinical samples, the positive-strand nsP3 qRT-PCR assay had higher R(2) and efficiency and detected more positive samples. Peak viral load of 12.9 log(10) RNA copies/mL was reached on day 2 of illness, and RNA was detectable up to day 9, even in the presence of anti-CHIKV IgM. There was no correlation between viral load and persistent arthralgia. The positive-strand nsP3 assay is suitable for diagnosis, while the negative-strand nsP3 assay, which uses tagged primers to increase specificity, is useful for study of active viral replication kinetics.

Matched MeSH terms: Sensitivity and Specificity
Transcriptome analysis of Burkholderia pseudomallei T6SS identifies Hcp1 as a potential serodiagnostic marker

Chieng S, Mohamed R, Nathan S

Microb Pathog, 2015 Feb;79:47-56.
PMID: 25616255 DOI: 10.1016/j.micpath.2015.01.006

Burkholderia pseudomallei, the causative agent of melioidosis, is able to survive extreme environments and utilizes various virulence factors for survival and pathogenicity. To compete and survive within these different ecological niches, B. pseudomallei has evolved specialized pathways, including the Type VI secretion systems (T6SSs), that have a role in pathogenesis as well as interbacterial interactions. We examined the expression profile of B. pseudomallei T6SS six gene clusters during infection of U937 macrophage cells. T6SS-5 was robustly transcribed while the other five clusters were not significantly regulated proposing the utility of T6SS-5 as a potential biomarker of exposure to B. pseudomallei. Transcription of T6SS regulators VirAG and BprB was also not significant during infection when compared to bacteria grown in culture. Guided by these findings, three highly expressed T6SS genes, tssJ-4, hcp1 and tssE-5, were expressed as recombinant proteins and screened against melioidosis patient sera by western analysis and ELISA. Only Hcp1 was reactive by both types of analysis. The recombinant Hcp1 protein was further evaluated against a cohort of melioidosis patients (n = 32) and non-melioidosis individuals (n = 20) sera and the data clearly indicates a higher sensitivity (93.7%) and specificity (100%) for Hcp1 compared to bacterial lysate. The detection of anti-Hcp1 antibodies in patients' sera indicating the presence of B. pseudomallei highlights the potential of Hcp1 to be further developed as a serodiagnostic marker for melioidosis.

Matched MeSH terms: Sensitivity and Specificity
Validation and application of capillary electrophoresis for the analysis of lidocaine in a skin tape stripping study

Chik Z, Johnston A, Tucker AT, Burn RT, Perrett D

Biomed Chromatogr, 2007 Aug;21(8):775-9.
PMID: 17497758

A fast and simple capillary zone electrophoresis method was developed and validated for the determination of lidocaine in skin using tape samples. Separation was performed in a 350 mm (265 mm to window) x 50 microm i.d. fused silica capillary using a background electrolyte of phosphoric acid-Tris pH 2.5. The extraction of lidocaine from tape samples was achieved using methanol, which was diluted to 50% with water before injection. Procaine was the internal standard. The migration times for procaine and lidocaine were 2.9 and 3.2 min, respectively. The limit of quantification for lidocaine was 50 microg, with signal to noise ratio greater than 10. The calibration curve was linear from 50 to 1000 microg with r(2) greater than 0.99. The CV for both within- and between-assay imprecision and the percentage of inaccuracy for the quality control samples including lower and upper limits of quantitation were 97%. The accuracy and selectivity of this method allowed the measurement of lidocaine in tape samples obtained from a skin tape stripping study of local anesthetics in healthy subjects.

Matched MeSH terms: Sensitivity and Specificity
Development of a TaqMan minor groove binding probe-based quantitative reverse transcription polymerase chain reaction for the detection and quantification of Zika virus

Chin KL, Teoh BT, Sam SS, Loong SK, Tan KK, Azizan NS, et al.

Trop Biomed, 2022 Dec 01;39(4):518-523.
PMID: 36602210 DOI: 10.47665/tb.39.4.005

Zika virus (ZIKV) infection has emerged as a global health concern following epidemic outbreaks of severe neurological disorders reported in Pacific and Americas since 2016. Therefore, a rapid, sensitive and specific diagnostic test for ZIKV infection is critical for the appropriate patient management and the control of disease spread. A TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed based on the conserved sequence regions of 463 ZIKV NS2B genes. The designed ZIKV qRT-PCR assay was evaluated for its detection limit, strain coverage and cross-reactivity. We further assessed the clinical applicability of qRT-PCR assay for ZIKV RNA detection using a total 18 simulated clinical specimens. The detection limit of the qRT-PCR assay was 11.276 ZIKV RNA copies at the 95% probability level (probit analysis, p<= 0.05). Both Asian and African ZIKV strains were detected by the qRT-PCR assay without cross-reacting with DENV-1, DENV-2, DENV-3, DENV-4, CHIKV, JEV, LGTV, GETV and SINV. The qRT-PCR assay demonstrated a perfect agreement (k = 1.000, P < 0.001) with the reference assay; the sensitivity and specificity of the qRT-PCR assay were 100% (95% CI= 79.6-100) and 100% (95% CI= 43.9-100) respectively. The qRT-PCR assay developed in this study is a useful diagnostic tool for the broad coverage detection and quantification of both the Asian and African ZIKV strains.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Agreement between calcaneal quantitative ultrasound and osteoporosis self-assessment tool for Asians in identifying individuals at risk of osteoporosis

Chin KY, Low NY, Kamaruddin AAA, Dewiputri WI, Soelaiman IN

Ther Clin Risk Manag, 2017;13:1333-1341.
PMID: 29070951 DOI: 10.2147/TCRM.S145519

BACKGROUND: Calcaneal quantitative ultrasound (QUS) is a useful tool in osteoporosis screening. However, QUS device may not be available at all primary health care settings. Osteoporosis self-assessment tool for Asians (OSTA) is a simple algorithm for osteoporosis screening that does not require any sophisticated instruments. This study explored the possibility of replacing QUS with OSTA by determining their agreement in identifying individuals at risk of osteoporosis.

METHODS: A cross-sectional study was conducted to recruit Malaysian men and women aged ≥50 years. Their bone health status was measured using a calcaneal QUS device and OSTA. The association between OSTA and QUS was determined using Spearman's correlation and their agreement was assessed using Cohen Kappa and receiver-operating curve.

RESULTS: All QUS indices correlated significantly with OSTA (p<0.05). The agreement between QUS and OSTA was minimal but statistically significant (p<0.05). The performance of OSTA in identifying subjects at risk of osteoporosis according to QUS was poor-to-fair in women (p<0.05), but not statistically significant for men (p>0.05). Changing the cut-off values improved the performance of OSTA in women but not in men.

CONCLUSION: The agreement between QUS and OSTA is minimal in categorizing individuals at risk of osteoporosis. Therefore, they cannot be used interchangeably in osteoporosis screening.

Matched MeSH terms: Sensitivity and Specificity*
A review on the performance of osteoporosis self-assessment tool for Asians in determining osteoporosis and fracture risk

Chin KY

Postgrad Med, 2017 Sep;129(7):734-746.
PMID: 28695762 DOI: 10.1080/00325481.2017.1353394

The prevalence of osteoporosis in Asian countries is growing. An effective screening method will enable patients at risk for osteoporosis to receive early diagnosis and treatment, and avoid overcrowding the limited dual-energy x-ray absorptiometry (DXA) machines available in Asian countries. Many simple osteoporosis screening algorithms have been developed but they are not validated for use in Asian populations. osteoporosis self-assessment tools for Asians (OSTA), established using a multinational Asian cohort, is the first screening algorithm that caters for the Asian populations. It considers only body weight and age in the algorithm. It shows consistently high performance and sensitivity in identifying postmenopausal women at risk for osteoporosis in many Asian countries. Its usage has been expanded for identifying osteoporosis in men, as well as determining fracture risk for both sexes. However, the performance of OSTA is influenced by age, sex, ethnicity and site of BMD measurement to define osteoporosis. Its usage is also limited in individuals without apparent risk factors. These limitations should be noted by physicians considering the use of OSTA in clinical setting. As a conclusion, OSTA is a cost-effective measure for osteoporosis screening in primary healthcare setting.

Matched MeSH terms: Sensitivity and Specificity
Fulltext Clinical diagnosis of malaria by medical assistants in Sri Aman, Sarawak - necessary but of limited reliability

Chin ZH

Malaysian Journal of Public Health Medicine, 2004;4(2):34-38.
MyJurnal

Rural health clinics in Sri Aman Division in Sarawak, Malaysia lack diagnostic tests for malaria. Many of the medical assistants in the clinic diagnose malaria solely on clinical ground. The study was to determine the sensitivity, specificity and positive predictive value of clinical diagnosis of rnahtria made by medical assistants using results of microscopy examination as gold standard. The study period was from September to December 2003. Three rural clinics without laboratory or diagnostic tests services and one urban clinic with laboratory facility serving malarious areas were selected. All patients clinically diagnosed as malaria by the attending medical assistants were included as clinical malaria cases. Blood slides were taken for examination of malaria parasites. Non clinical malaria cases were all other patients without clinical malaria for whom blood slides were taken for malaria parasites. Out of 362 patients included in the study, 75 were clinically diagnosed as having mahria. The sensitivity of headache, history of fever and chills/rigors to detect malaria cases was above 90% but the specificity and positive predictive value was low, below 40% and 20% respectively. The sensitivity, specificity and positive predictive value of malaria clinical diagnosis made by medical assistants was 82.1 %, 84 .4% and 30.7% respectively. Clinical diagnosis of malaria increases the slide positive rate by four folds. However the sensitivity, specincity and positive predictive value of clinical diagnosis by medical assistant and clinical characteristics was insufficient to enable each of them to be used alone to differentiate true malaria cases from non mahiria cases.

Matched MeSH terms: Sensitivity and Specificity
Evaluation of Toxoplasma gondii-recombinant dense granular protein (GRA2) for serodiagnosis by western blot

Ching XT, Lau YL, Fong MY, Nissapatorn V

Parasitol Res, 2013 Mar;112(3):1229-36.
PMID: 23274488 DOI: 10.1007/s00436-012-3255-5

Toxoplasma gondii infects all warm-blooded animals including humans, causing serious public health problems and great economic loss in the food industry. Commonly used serological tests involve preparation of whole Toxoplasma lysate antigens from tachyzoites which are costly and hazardous. An alternative method for better antigen production involving the prokaryotic expression system was therefore used in this study. Recombinant dense granular protein, GRA2, was successfully cloned, expressed, and purified in Escherichia coli, BL21 (DE3) pLysS. The potential of this purified antigen for diagnosis of human infections was evaluated through western blot analysis against 100 human serum samples. Results showed that the rGRA2 protein has 100 and 61.5 % sensitivity towards acute and chronic infection, respectively, in T. gondii-infected humans, indicating that this protein is useful in differentiating present and past infections. Therefore, it is suitable to be used as a sensitive and specific molecular marker for the serodiagnosis of Toxoplasma infection in both humans and animals.

Matched MeSH terms: Sensitivity and Specificity

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