Displaying publications 81 - 100 of 1044 in total

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  1. Lai FM, Liam CK, Paramsothy M, George J
    Int J Tuberc Lung Dis, 1997 Dec;1(6):563-9.
    PMID: 9487455
    University Hospital, Kuala Lumpur, Malaysia.
    Matched MeSH terms: Sensitivity and Specificity
  2. Lange B, Khan P, Kalmambetova G, Al-Darraji HA, Alland D, Antonenka U, et al.
    Int J Tuberc Lung Dis, 2017 05 01;21(5):493-502.
    PMID: 28399963 DOI: 10.5588/ijtld.16.0702
    SETTING: Xpert® MTB/RIF is the most widely used molecular assay for rapid diagnosis of tuberculosis (TB). The number of polymerase chain reaction cycles after which detectable product is generated (cycle threshold value, CT) correlates with the bacillary burden.OBJECTIVE To investigate the association between Xpert CT values and smear status through a systematic review and individual-level data meta-analysis.

    DESIGN: Studies on the association between CT values and smear status were included in a descriptive systematic review. Authors of studies including smear, culture and Xpert results were asked for individual-level data, and receiver operating characteristic curves were calculated.

    RESULTS: Of 918 citations, 10 were included in the descriptive systematic review. Fifteen data sets from studies potentially relevant for individual-level data meta-analysis provided individual-level data (7511 samples from 4447 patients); 1212 patients had positive Xpert results for at least one respiratory sample (1859 samples overall). ROC analysis revealed an area under the curve (AUC) of 0.85 (95%CI 0.82-0.87). Cut-off CT values of 27.7 and 31.8 yielded sensitivities of 85% (95%CI 83-87) and 95% (95%CI 94-96) and specificities of 67% (95%CI 66-77) and 35% (95%CI 30-41) for smear-positive samples.

    CONCLUSION: Xpert CT values and smear status were strongly associated. However, diagnostic accuracy at set cut-off CT values of 27.7 or 31.8 would not replace smear microscopy. How CT values compare with smear microscopy in predicting infectiousness remains to be seen.

    Matched MeSH terms: Sensitivity and Specificity
  3. Bicchierai G, Nori J, De Benedetto D, Boeri C, Vanzi E, Bianchi S, et al.
    Breast J, 2020 02;26(2):299-302.
    PMID: 31486197 DOI: 10.1111/tbj.13598
    Matched MeSH terms: Sensitivity and Specificity
  4. Al-Mekhlafi MA, Fatmah MS, Anisah N, Azlin M, Al-Mekhlafi HM, Norhayati M
    PMID: 21323160
    Abstract. The species identification of Enterocytozoon bieneusi and Encephalitozoon intestinalis is only possible using transmission electron microscopy (TEM), mo lecular techniques and immunofluorescence antibody assays (IFA). In this study, 50 positive and 50 negative fecal specimens for microsporidial spores using the Weber modified trichrome (WMT) staining technique were examined using IFA-MAbs. Of the 100 specimens examined, the microsporidial spores identified by IFA-MAbs were Enterocytozoon Bieneusi 42 (75%) Encephalitozoon intestinalis 7 (12.5%) and mixed infections 7 (12.5%). The sensitivity and specificity of IFA-MAbs in detecting microsporidial spores were 98% and 86%, respectively. The agreement between the WMT staining technique and IFA-MAbs was statistically significant by Kappa statistics (K = 0.840; p < 0.001). E. bieneusi was the commonest Microsporidia species isolated from the studied population; the presence of microsporidial spores detected by IFA-MAbs should be confirmed by other methods.
    Matched MeSH terms: Sensitivity and Specificity
  5. Puthucheary SD, Anuar AS, Tee TS
    PMID: 20578523
    An immunofluorescent assay (IFAT) using whole cell antigen derived from Burkholderia thailandensis used for detection of total antibodies to Burkholderia pseudomallei, was found to compare favorably with a previous published report on a B. pseudomallei IFAT assay. At a 1:20 cut-off titer, the assay had high sensitivity (98.9%) and satisfactory specificity (92.3%), when tested against sera from 94 patients suspected of melioidosis. Sera from 12 patients with culture proven melioidosis gave absolute concordance with the 2 test antigens. No sera from 50 blood donors had a titer of > or =20. Cross-reactivity with patients' sera positive for Chlamydia, Mycoplasma, Legionella and typhoid was not observed, except for 3 sera from typhus patients and one from a patient with leptospirosis. The major advantage of this assay is that the cultivation and preparation of B. thailandensis as antigen can be carried out in any laboratory with basic microbiological set-up. The serodiagnosis of melioidosis can be made safe for medical laboratory personnel, particularly in B. pseudomallei endemic regions.
    Matched MeSH terms: Sensitivity and Specificity
  6. Meganathan P, Singh S, Ling LY, Singh J, Subrayan V, Nissapatorn V
    PMID: 20578507
    Detection of Toxoplasma gondii in blood by means of the polymerase chain reaction (PCR) may facilitate early diagnosis of toxoplasmosis in different groups of patients. We evaluated this approach in 42 patients presenting with ocular or psychotic diseases by comparing the sensitivity and specificity of PCR after heat treatment using a microwave oven with a standard genomic DNA extraction method for paired serum and whole blood samples. The presence of serum IgM and IgG antibodies against T. gondii was detected using a standard commercial enzyme-linked immunosorbent assay and enzyme immunoassay for IgG avidity test. Of 42 whole blood samples, PCR after microwave treatment was positive in 8 samples with a sensitivity of 73% and specificity of 100% compared to 11 samples positive by the extraction method. Although none of 42 sera samples was PCR positive by the extraction method, 7 specimens were positive after microwave treatment. This is the first study to use a microwave heat treatment, which is simple, rapid and a promising alternative method, in detecting small amounts of T. gondii DNA in human blood. Furthermore, irradiation of blood samples with microwaves allows incorporation of PCR into a practical tool for routine clinical assessment of patients with Toxoplasma infection.
    Matched MeSH terms: Sensitivity and Specificity
  7. Ling LY, Ithoi I, Yik FM
    PMID: 20578535
    SAG2 is one of the major surface antigens of the intracellular protozoan parasite Toxoplasma gondii. In the present study, truncated recombinant SAG2(S) and full length recombinant SAG2(T) of T. gondii were optimally produced (approximately 15 mg/liter) in Pichia pastoris expression system using BMMY medium at pH 3, 25 degrees C in 0.5-1% methanol and a time-course of 1-2 days. The recombinant proteins were purified using a commercial gel filtration purification system obtaining approximately 33% recovery. The purified SAG2(S) and SAG2(T) showed molecular masses of 45 and 36 kDa by SDS-PAGE, respectively. The recombinant proteins were evaluated by Western blotting with patients' sera and demonstrated 90% sensitivity and 100% specificity for detection of toxoplasmosis. This study provided a means for large-scale expression and purification of SAG2, which should be useful for diagnosis of toxoplasmosis.
    Matched MeSH terms: Sensitivity and Specificity
  8. Zaidah AR, Chan YY, Asma HS, Abdullah S, Nurhaslindawati AR, Salleh M, et al.
    PMID: 18564692
    This cross-sectional study determined the prevalence of cryptosporidiosis in HIV-infected patients using polymerase chain reaction (PCR). Stool specimens were collected from HIV infected patients who were admitted to Hospital Raja Perempuan Zainab II, Kota Bharu, Malaysia, for various indications from December 2004 to December 2005. A modified acid-fast stain was performed on the direct stool smears, then the stool specimens were further tested using nested PCR targeting the 18S rRNA gene of Cryptosporidium parvum, with a built-in internal control (IC). Out of 59 samples, 11 were positives. Nested PCR identified a total of nine samples (16%) compared to microscopy, which identified only three samples. All PCR negative results showed IC amplicons, suggesting that these samples were true negatives and were not due to inhibition of PCR. This study highlights the importance of molecular diagnosis in determining the true prevalence and epidemiology of C. parvum.
    Matched MeSH terms: Sensitivity and Specificity
  9. Maheswaran M, Adnan WA, Ahmad R, Ab Rahman NH, Naing NN, Abdullah J
    PMID: 18613557
    Non-traumatic Altered States of Consciousness (ASC) are a non-specific consequence of various etiologies, and are normally monitored by Glasgow Coma Scale (GCS). The GCS gives varriable results among untrained emergency medicine personel in developing countries where English is not the first language. An In House Scoring System (IHSS) scale was made by the first author for the purpose of triaging so as to quickly asses patients when seen by medical personel. This IHSS scale was compared to the GCS to determine it's specificity and sensitivity in the accident and emergency department (ED) of Hospital University Sains Malaysia (HUSM). All patients with non-traumatic ASC were selected by purposive sampling according to pre-determined criteria. Patients were evaluated by the two systems, IHSS and GCS, by emergency physicians who were on call. Patient demographics, clinical features, investigations, treatment given and outcomes were collected and followed for a period of 14 days. A total of 221 patients with non-traumatic ASC were studied, 54.3% were males. The mean age of the patients was 56 years old. The mean overall GCS score on presentation to the ED was 10.3. The mean duration of ASC was 11.6 hours. One hundred thirty patients (58.8%) experienced ASC secondary to general or focal cerebral disorders. The mortality rate was 40.3% 2 weeks after the ED visit. Fifty-four point three percent of the patients were awake and considered to have good outcomes while 45.7% of the patients had poor outcomes (comatose or dead) 2 weeks after the ED visit. The mean overall GCS score, verbal and motor subscores as well as the IHSS had significantly decreased (worsened) after treatment in the ED. A poor IHSS scale, hypertension, current smoking, abnormal pupillary reflexes and acidosis were associated with a worse 2-week outcome. The mean age and WBC count was lower and the mean overall GCS score and eye, verbal and motor subscores were higher as well as those having a lower IHSS scale for the good outcome category. Multivariate analysis revealed that smokers and hypertensives were at higher risk for a poor outcome. Higher eye scores on the GCS were associated fewer poor outcomes. There was significant agreement between the IHSS scale and GCS scores in the assessment of non-traumatic ASC. The sensitivity and specificity of the IHSS score versus GCS were 71.9% and 100.0%, respectively.
    Matched MeSH terms: Sensitivity and Specificity
  10. Edimansyah BA, Rusli BN, Naing L, Mazalisah M
    PMID: 17125008
    The JCQ has been shown to be a valid and reliable instrument to assess job stress in many occupational settings worldwide. In Malaysia, both the English and validated Malay versions have been employed in studies of medical professionals and laboratory technicians, respectively. The present study assessed the reliability and construct validity of the Malay version of the JCQ among automotive workers in Malaysia. Fifty workers of a major automotive manufacturer in Kota Bharu, Kelantan consented to participate in the study and were administered the Malay version of the JCQ. Translation (English-Malay) and back translation (Malay-English) of the JCQ was made to ensure the face validity of the questionnaire. Reliability was determined using Cronbach's alpha for internal consistency, whilst construct validity was assessed using exploratory factor analysis (principal component with varimax rotation). The results indicate that the Cronbach's alpha coefficients were acceptable for decision latitude (job control or decision authority) (0.74) and social support (0.79); however, it was slightly lower for psychological job demand (0.61). Exploratory factor analysis showed 3 meaningful common factors that could explain the 3 theoretical dimensions or constructs of Karasek's demand-control-social support model. In conclusion, the results of the validation study suggested that the JCQ scales are reliable and valid for assessing job stress in a population working in the automotive industry. Further analyses are necessary to evaluate the stability and concurrent validity of the JCQ.
    Matched MeSH terms: Sensitivity and Specificity
  11. Mohamed Y, Alias NN, Shuaib IL, Tharakan J, Abdullah J, Munawir AH, et al.
    PMID: 17333778
    Advances in neuroimaging techniques, particularly Magnetic Resonance Imaging (MRI), have proved invaluable in detecting structural brain lesions in patients with epilepsy in developed countries. In Malaysia, a few electroencephalography facilities available in rural district hospitals run by trained physician assistants have Internet connections to a government neurological center in Kuala Lumpur. These facilities are more commonly available than MRI machines, which require radiological expertise and helium replacement, which may problematic in Southeast Asian countries where radiologists are found in mainly big cities or towns. We conducted a cross-sectional study over a two year period begining January 2001 on rural patients, correlating EEG reports and MRI images with a clinical diagnosis of epilepsy to set guidelines for which rural patients need to be referred to a hospital with MRI facilities. The patients referred by different hospitals without neurological services were classified as having generalized, partial or unclassified seizures based on the International Classification of Epileptic Seizures proposed by the International League Against Epilepsy (ILAE). The clinical parameters studied were seizure type, seizure frequency, status epilepticus and duration of seizure. EEG reports were reviewed for localized and generalized abnormalities and epileptiform changes. Statistical analysis was performed using logistic regression and area under the curve. The association between clinical and radiological abnormalities was evaluated for sensitivity and specificity. Twenty-six males and 18 females were evaluated. The mean age was 20.7 +/- 13.3 years. Nineteen (43.2%) had generalized seizures, 22 (50.0%) had partial seizures and 3 (6.8%) presented with unclassified seizures. The EEG was abnormal in 30 patients (20 with generalized abnormalities and 10 localized abnormalities). The MRI was abnormal in 17 patients (38.6%); the abnormalities observed were cerebral atrophy (5), hippocampal sclerosis (4), infarct/gliosis (3), cortical dysgenesis (2) and tumors (2). One patient had an arachnoid cyst in the right occipital region. Of the 17 patients with an abnormal MRI, 14 had an abnormal EEG, this difference was not statistically significant. There was no significant associaton between epileptographic changes and MRI findings (p = 0.078). EEG findings were associated with MRI findings (p = 0.004). The association between an abnormal EEG and an abnormal MRI had a specificity of 82.4%, while epileptogenic changes had a specificity of 64.7% in relation to abnormal MRI findings. This meants that those patients in rural hospitals with abnormal EEGs should be referred to a neurology center for further workup and an MRI to detect causes with an epileptic focus.
    Matched MeSH terms: Sensitivity and Specificity
  12. Josephine FP, Nissapatorn V
    PMID: 16438183
    This retrospective and descriptive study was carried out in the University of Malaya Medical Center (UMMC) from January to September, 2004. This study aimed to evaluate the diagnostic utility of the Cell-Dyn 4000 hematology analyzer's depolarization analysis and to determine the sensitivity and specificity of this technique in the context of malaria diagnosis. A total of 889 cases presenting with pyrexia of unknown origin or clinically suspected of malaria were examined. Sixteen of these blood samples were found to be positive; 12 for P. vivax, 3 for P. malariae, and 1 for P. falciparum by peripheral blood smear as the standard technique for parasite detection and species identification. Demographic characteristics showed that the majority of patients were in the age range of 20-57 with a mean of 35.9 (+/- SD) 11.4 years, and male foreign workers. Of these, 16 positive blood samples were also processed by Cell-Dyne 4000 analyzer in the normal complete blood count (CBC) operational mode. Malaria parasites produce hemozoin, which depolarizes light and this allows the automated detection of malaria during routine complete blood count analysis with the Abbot Cell-Dyn CD4000 instrument. The white blood cell (WBC) differential plots of all malaria positive samples showed abnormal depolarization events in the NEU-EOS and EOS I plots. This was not seen in the negative samples. In 12 patients with P. vivax infection, a cluster pattern in the Neu-EOS and EOS I plots was observed, and appeared color-coded green or black. In 3 patients with P. malariae infection, few random depolarization events in the NEU-EOS and EOS I plots were seen, and appeared color-coded green, black or blue. While in the patient with P. falciparum infection, the sample was color-coded green with a few random purple depolarizing events in the NEU-EOS and EOS I plots. This study confirms that automated depolarization analysis is a highly sensitive and specific method to diagnose whether or not a patient has malaria. This automated approach may prove to be particularly useful in situations where there is little or no clinical suspicion of malaria.
    Matched MeSH terms: Sensitivity and Specificity
  13. Vythilingam I, Nitiavathy K, Yi P, Bakotee B, Hugo B, Singh B, et al.
    PMID: 10928352
    Dried Anopheles farauti mosquitos caught in Solomon Islands in 1990 were examined for malaria sporozoites by ELISA and nested polymerase chain reaction (PCR). Only heads and thoraces were used. Plasmodium genus-specific nested PCR amplifications were carried out on all samples. Of the 402 pools of mosquitos that were processed, 30 were positive for malaria. Nest 1 products of positive samples were subjected to further PCR amplifications with species-specific primers for P. falciparum and P. vivax. Twenty pools were positive for P. vivax by PCR while only 7 were positive by ELISA. For P. falciparum 2 pools were positive by both ELISA and PCR, and one of these was a pool which was positive for P. vivax by PCR and ELISA. Thus the sensitivity of PCR for P. vivax was 100% while the specificity was 96.7%. For P. falciparum the sensitivity and specificity were 100%. The PCR technique is highly sensitive and can be used on dried mosquitos which makes it a valuable tool for determining sporozoite rates of mosquitos, even in remote areas.
    Matched MeSH terms: Sensitivity and Specificity
  14. Salasawati H, Ramelah M, Pitt TL, Holmes B
    PMID: 10772579
    The purpose of this investigation was to evaluate the usefulness of a co-agglutination procedure for the typing of Flavobacterium meningosepticum. The sensitivity and specificity of the co-agglutination test was compared to the slide agglutination test using reference strains of the bacterial species. Antisera were characterized by both technics to determine their titer and working dilution. The specificity of the sera was assessed by performing tests which include strains of other species and serotypes. A collection of 47 strains of F. meningosepticum isolated from clinical specimens were typed by both co-agglutination and slide agglutination methods. Co-agglutination proved to be markedly more specific than the slide procedure although both methods were similar in sensitivity. It was concluded that co-agglutination proved to be an excellent method for the serotyping of F. meningosepticum.
    Matched MeSH terms: Sensitivity and Specificity
  15. Abdullah WO, Oothuman P, Yunus H
    PMID: 7973943
    In Peninsular Malaysia, only Wuchereria bancrofti and Brugia malayi are reported to cause human filariasis. Brugia pahangi infects many of the same animal hosts as the zoonotically transmitted subperiodic B. malayi. There is a well-recognized need for improved diagnostic techniques for lymphatic filariasis. Parasite antigen detection is a promising new approach, and it will probably prove to be more sensitive and specific than clinical, microscopic and antibody-based serological methods. We recently generated monoclonal antibodies (MAb XC3) from in vitro culture products of adult B. pahangi (B.p. IVP). Filarial antigenemia was quantitated in various hosts including the sera from 6 Malaysian Aborigines with acute lymphatic filariasis. In hosts infected with brugian filariasis and dirofilariasis, antigenemia was scored ranging from 90 ng/ml to 960 ng/ml. None of the control animal and human sera had antigenemia above 90 ng/ml. In addition, MAb XC3 and B.p. IVP were applied in several seroepidemiological surveys among household cats in Kuala Selangor in order to correlate information gathered for future studies of possible cases of human infection. Out of the 81 cats surveyed, 10 (12.35%) and 5 (6.17%) were parasitologically positive for B. pahangi and B. malayi, respectively. However, 21 (25.92%) were antigenemia positive when serologically investigated with MAb XC3. Antifilarial antibodies to B.p. IVP by direct ELISA showed very high cross-reactivity with non-filarial gut worm infections. 16 (19.75%) cats had reciprocal titers ranging from 320 to 2,560. Only 1 (1.23%) cat from this group was antigenemic.
    Matched MeSH terms: Sensitivity and Specificity
  16. Normaznah Y, Furuta T, Saniah K, Noor Rain A, Kojima S, Mak JW
    PMID: 9444035
    Matched MeSH terms: Sensitivity and Specificity
  17. Eamsobhana P, Yong HS, Mak JW, Wattanakulpanich D
    PMID: 9561620
    A dot-blot ELISA was compared with a previously performed sandwich ELISA for the detection of Parastrongylus cantonensis antigens in sera from patients. Using the same monoclonal antibody and the same sera, 6 of 10 sera (60%) from parastronglyiasis patients were positive in dot-blot ELISA, whereas with sandwich ELISA, 5 of the same patient sera (50%) were positive. The specificity in both assays was 100% using 50 sera from patients with other parasitic diseases; of these, 10 each were from patients with cysticercosis, filariasis, gnathostomiasis, malaria and toxocariasis. The control group consisted of 53 sera from normal health Thais and Malaysians. The sensitivity of the assays was, however, slightly better with dot-blot ELISA and because it is simple, quick and cost-effective, it may be a test of choice for specific diagnosis of human parastrongyliasis.
    Matched MeSH terms: Sensitivity and Specificity
  18. Norazah A, Rohani MY, Chang PT, Kamel AG
    PMID: 9279987
    Interpretation of the indirect hemagglutination test (IHA) for melioidosis in endemic areas is difficult because of the presence of antibodies in apparently healthy individuals. Fifty-three out of 200 healthy blood donors in Malaysia showed positive antibody titers (> or = 1 : 40) against Burkholderia pseudomallei. Seven percent had an IHA titer of 1 : 40, 11% had an IHA titer of 1 : 80 while 8.5% had a titer > or = 1 : 160. Out of 258 sera sent for melioidosis serology, 7% of the patients had an IHA titer of 1 : 40, 9% had an IHA titer of 1 : 80 while 20% had an IHA titer of > or = 1 : 160. If a titer of > or = 1 : 80 is taken as cut off point for positivity, 29% of the patients had positive melioidosis serology. Increasing the positivity threshold may jeopardize the sensitivity of the test. A more specific and sensitive test is needed.
    Matched MeSH terms: Sensitivity and Specificity
  19. Chua KB, Khairullah NS, Hooi PS
    PMID: 9031408
    Sera from healthy donors and patients stored over a period of 2 years, aged 1 to 83 years, were examined for reactivity to human herpes virus 6 (HHV-6) by the standard indirect immunofluorescence assay (IFA). Of the 600 serum specimens screened, 502 showed positive reactivity to HHV-6. This gives an overall seropositive rate of 83.7%. There is no significant difference in the overall positive rate between the ethnic groups (Chinese, Malays, Indians) (chi 2 = 0.35 df = 2 p > 0.05). However, there is significant difference in the positive rates at the extreme age groups of 1 year as well as 61 years and above. From birth up to below 1 year of age, the seroprevalence rate was 82%. At one year of age the positive rate decreased to 66% before gradually rising so that the percentage seropositivity of 6 to 10 years old becomes similar to that in older children and adults (11 to 40 years). The positive rate then starts to decline after 40 years of age. Using a standardized scoring system, the corresponding antibody titer was found to be high in the very young population and starts to decline after the age of 15 years. This suggests that in our population group, primary infection occurs mainly in the pediatric age group. It also accounts for the low positive rate in the age group of 61 years and above, as by then the titer had fallen to the level below the detection limits of the assay system.
    Matched MeSH terms: Sensitivity and Specificity
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