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PubMed1999

Comparison of a transcription-mediated amplification assay and polymerase chain reaction for detection of Chlamydia trachomatis in first-void urine.

The performance of a commercial transcription-mediated amplification (TMA) assay (Gen-Probe Amplified Chlamydia trachomatis Assay; Gen-Probe, USA) was compared with that of the Roche Cobas Amplicor CT/NG polymerase chain reaction (PCR) (F. Hoffmann-La Roche, Switzerland) for detection of Chlamydia trachomatis in urine specimens. First-void urine specimens were collected from 658 patients: 320 men and 338 women. The results of the two tests were identical for 650 (98.8%) of the 658 patients. Among them, the test results were uniformly positive for 72 patients: 39 men and 33 women. In the cases in which the initial results of TMA assay and PCR were discrepant the specimens were reanalyzed and tested by an alternative TMA assay and a major outer membrane protein-based PCR. After analysis of discrepant results. 74 specimens (11.2%) were considered positive. All positive results were correctly identified by TMA assay, whereas PCR gave two false-negative and six false-positive results.

Chlamydia Infections↗
PubMed2001

Highly sensitive immunohistological study for detection of estrogen receptor in human breast cancer.

BACKGROUND: Immunohistological methods for the detection of estrogen receptor in human breast cancer using formalin-fixed, paraffin-embedded tissue not only have the advantages of being cheaper and requiring less tissue but also have several theoretical advantages. For example, such methods enable direct histological visualization of the assessed tissue and thereby reduce sampling error. Traditional immunohistological methods (traditional LSAB), however, show false-negative reactions more often than the enzyme-binding immunoassay method (EIA). METHODS: After determining 25 estrogen receptor-positive cases and 50 estrogen receptor-negative cases by EIA, we analyzed these same cases using a traditional LSAB method and a new highly sensitive immunohistological method for assaying formalin-fixed, paraffin-embedded tissue. RESULTS: Using this new method, we detected 10 instances of positive estrogen receptors among the 50 EIA receptor-negative cases. The 25 EIA-positive cases were positive for estrogen receptor antigen except 1case using the new method. CONCLUSIONS: This new method not only has the advantage of use in paraffin-embedded tissue but also is more sensitive than the EIA. We recommend this new method as a choice to decrease false-negatives.

Adult↗
PubMed1985

Occult blood screening for colorectal carcinoma: a critical review.

The author reviews the literature on occult blood surveillance for colorectal carcinoma. The guaiac-based Hemoccult (SmithKline Diagnostics, Sunnyvale, Calif.) test is the most reliable and widely used. However, testing is complicated by several technical issues that can affect clinical results, and even successful screening programs will miss a high proportion of tumors. Public compliance is often poor, and a number of indirect and "hidden" costs make surveillance programs much more expensive than is usually claimed. Almost all published screening trials are uncontrolled. They generally detect about 3-20 colorectal malignancies for every 10,000 people enrolled, but only about 5%-10% of occult blood reactions are due to cancer. Though screen-detected tumors tend to be at a relatively early stage, this does not imply any benefit of surveillance because of lead time and length biases inherent in the screening process. Only controlled trials can answer the central question of whether screening decreases mortality from bowel cancer. Two such trials are underway, but mortality data are not yet available from either.

Colonic Neoplasms↗
PubMed1990

Clinical significance of Mantoux test in Malaysian patients.

The value of tuberculin skin testing in the diagnosis of active tuberculosis remains uncertain. Interpretation of tuberculin tests would be easier if the tuberculin test profiles in different communities were accurately known. We reviewed 468 Mantoux test reactions in patients coming to Hospital Universiti Sains Malaysia with suspected tuberculosis. Eighty six percent of patients with active tuberculosis had a positive Mantoux test. Forty two percent of the cases of positive Mantoux test did not have evidence of active tuberculosis. Most of these cases had evidence of past infection with tuberculosis. We conclude that Mantoux test is a sensitive but a non-specific test in the diagnosis of active tuberculosis.

False Negative Reactions↗
PubMed1977

[Diagnostic significance of identification of anti-entamoeba histolytica antibodies (author's transl)].

Examinations were performed with the indirect immunofluorescence test (IFAT) and the indirect haemagglutination test (IHAT). Negative titers (less than 1:5) do not exclude an infection with E. histolytica. Titers up to 1:80 in both reactions are found in patients with negative stool specimens or indicate an asymptomatic infection of the intestinal lumen, an incipient or past symptomatic amoebiasis. IFAT values of 1:160 together with a negative or positive IHAT are also suggestive of the two last-mentioned types of infection. These titers are also found in patients with gastrointestinal disorders of other orgin. IFAT values higher than 1:60 with a positive IHAT are probably due to an invasive amoebiasis. Titres are, however, only diagnostic pointers.

Amebiasis↗
PubMed2006

Umbilical cord blood transplantation and cytomegalovirus: Posttransplantation infection and donor screening.

This study assessed the incidence of cytomegalovirus (CMV) infection after transplantation of cord blood (CB) from unrelated donors and evaluated strategies for screening CB donors. Posttransplantation CMV infection, reported in 23% of 1221 CB recipients, was associated with patient pretransplantation CMV serology (P < .001), but not with CMV serology in CB donors or their mothers. A total of 26 988 infant CB donors were evaluated by viral culture of saliva. Subgroups were evaluated by polymerase chain reaction in CB (CB-PCR) in 2 case-control studies. In the first study, 33 of 47 saliva culture-positive CB donors were confirmed by CB-PCR. All mothers of the 33 infants with confirmed CMV infection were CMV-total antibody positive, but only 1 of 3 had CMV-IgM antibody. The second study evaluated infants born to mothers with CMV-IgM antibody. Of these, 5 of 170 saliva culture-negative infants were positive by CB-PCR. The incidence of congenital CMV infection in CB donors was low (0.12%). Maternal serology had poor predictive value for CMV infection in their infant CB donors and bore no detected relationship to CMV infection in CB recipients. Saliva culture for CMV had both false-positive and -negative results. CB-PCR was a useful alternative for detecting CMV in CB donors.

Adolescent↗
PubMed1975

[How effective are tests for avoiding contrast reactions].

The frequency of known severe and fatal reactions after intravenous injections of biligrafin forte were compared during two periods. During the first period test ampules were provided; during the second period, the test ampules were no longer made. It was shown that the failure to perform tests did not result in any increase in the complication rate when compared with the period when test ampules were available. The problems arising from this comparison are discussed.

Biliary Tract Diseases↗
PubMed1984

Microtests for rapid identification of Enterobacteriaceae. Four-hour tests by use of substrate-impregnated paper discs.

A number of microtests for the diagnosis of Enterobacteriaceae in 4 hours were developed. Composition of substrates and preparation of reaction wells are described. There were used substrate-impregnated paper discs affixed to microwell plates. Test results of 253 stock cultures of Enterobacteriaceae were correlated with results obtained by conventional tube methods. Twenty out of 23 microtests showed total correlations of more than 95%, and the remaining 3 tests 85-94%. The microtests are concluded to be economic and reliable alternatives to conventional tube methods and seem suitable for routine identification of Enterobacteriaceae.

Bacteriological Techniques↗
PubMed1998

Characteristics of selective polymerase chain reaction (PCR) using two-base anchored primers and improvement of its specificity.

We have developed a reliable method for eliminating base-mispair amplification in selective polymerase chain reaction (PCR), which is utilized for amplifying unknown sequence fragments produced by restriction enzyme reaction. The proposed procedure applies amplified fragment length polymorphism (AFLP) with high fidelity. Selective PCR utilizes the known polymerase reaction characteristic that the complementary strand extension is strongly affected by matching a template with the 3'-terminus of the primers. However, false positive amplification is frequently observed because the specificity of terminal bases for discrimination of fragments (usually, 1-3 anchor sequences) is not enough to separate each fragment. A protocol for the selective PCR separation of every fragment was therefore investigated. A single-base mismatch was artificially introduced on the 4th base position from the 3' end of the primers to improve the hybridization specificity of anchored 2-bases at the 3' termini of primers. PCR reaction was carried out at 66 degrees C to prevent false positive amplification. The concentration of the primers having anchored-base sequences of AA, AT, TA, and TT must be three times larger than that of other primers because the Tm values for these sequences are lower than the others. As all the fragments can be separated into groups with high fidelity, the improved selective PCR will be applied to gene finding and analyzing differences on genome sequences based on AFLP.

DNA Primers↗
PubMed1990

Application of monoclonal antibodies in diagnosis of human breast cancer by fine-needle aspiration cytology.

In the present study the authors have examined 100 breast nodules by fine-needle aspiration cytology (FNAC) using the avidin-biotin complex method of immunoperoxidase staining. The monoclonal antibodies (MAbs) employed, B 6.2 and B 72.3, recognize two distinct molecules expressed by transformed breast epithelium. The authors have compared this immunocytochemical reaction with the conventional cytology and the histological examination as well. The data of the MAbs alone or in combination have been evaluated in terms of sensitivity, specificity, predictive value and test efficiency. The results show that tumor cells are strongly reactive with the MAbs. So the authors believe that this method in conjunction with conventional cytology may be useful in the diagnosis of breast tumor, especially in doubtful FNAC.

Antibodies, Monoclonal↗
PubMedDate not supplied

Predictive value of testing random urine sample to detect microalbuminuria in diabetic subjects during outpatient visit.

The predictive value of random urine sample during outpatient visit to predict persistent microalbuminuria was studied in 76 Type 1, insulin-dependent diabetic subjects, 61 Type 2, non-insulin-dependent diabetic subjects, and 72 Type 2, insulin-treated diabetic subjects. Seventy-six patients attended outpatient clinic during morning, and 133 during afternoon. Microalbuminuria was suspected if Urinary Albumin Excretion (UAE) exceeded 20 mg/l. All patients were hospitalized within 6 months following outpatient visit, and persistent microalbuminuria was assessed then if UAE was between 30 and 300 mg/24 h on 2-3 occasions in 3 urines samples. Of these 209 subjects eighty-three were also screened with Microbumintest (Ames-Bayer), a semi-quantitative method. Among the 209 subjects, 71 were positive both for microalbuminuria during outpatient visit and a persistent microalbuminuria during hospitalization: sensitivity 91.0%, specificity 83.2%, concordance 86.1%, and positive predictive value 76.3% (chi-squared test: 191; p less than 10(-4)). Data were not different for subjects examined on morning, or on afternoon. Among the 83 subjects also screened with Microbumintest, 22 displayed both a positive reaction and a persistent microalbuminuria: sensitivity 76%, specificity 81%, concordance 80%, and positive predictive value 69% (chi-squared test: 126; p less than 10(-4)). Both types of screening appeared equally effective during outpatient visit. Hence, a persistent microalbuminuria can be predicted during an outpatient visit in a diabetic clinic.

Adult↗
PubMedDate not supplied

[A complex approach to the diagnosis of HIV-1 infection: the use of the polymerase chain reaction as an alternative confirmatory test].

The results of the three-year observation of female patient St. in whose blood antibodies to HIV disappeared in the course of time and the results of the laboratory study of the blood sera of children born of HIV-infected mothers are presented. In these patients correct diagnosis could be made only with the use of a complex of virological and molecular-biological methods.

AIDS Serodiagnosis↗
PubMed2001

[Evaluation of the immediate transfusion reaction incident reporting system at the Brest University Hospital Center].

The Haemovigilance Unit of Brest University Hospital has had a reporting system of transfusion reactions since october 1994. Reporting "any unexpected or undesirable effect due or likely to be due to the administering of blood cell components" must be done on an answering machine immediately or in the next eight hours. The main goal of the evaluation of this epidemiological surveillance system was to assess its sensitivity, its positive predictive value, its acceptability, its timeliness and its simplicity, according to the Centers for Disease Control criteria. An exhaustive monitoring of the immediate transfusion reactions (ITR) occurring within the 24 hours following the procedure was conducted from April 1, to June 30, 1998. Two sources of information were used, the spontaneous notification to the Haemovigilance Unit using the answering machine, and a telephone survey of the nurse responsible for the transfusion or post-transfusion follow-up. During the survey, 19 ITR, among which 12 were reported to the Haemovigilance Unit on the answering machine, were recorded. The incidence rate of the I.T.R. was estimated at 5@1000 transfused blood cell components. The sensitivity of the notification system was estimated at 63% (95% confidence interval: 41-85) and the positive predictive value at 70% (95% confidence interval: 48-92). This notification system is operational. The function of sanitary alert is ensured at the primary level of the system surveillance. The undernotification of the ITR (37% of false negative) must be corrected by specific recommendations.

Academic Medical Centers↗
PubMed1981

[Measurement of skin temperature in breast cancer--a new possibility of early diagnosis].

The local skin temperature was measured by infrared thermometry in 100 women suffering from malign neoplasms of the breast. After thermal stimulation the reaction of the skin temperature was determined in a repeated measurement. The results were compared with standard temperature values obtained in 100 healthy women. Statistical evaluation of the data using discriminant analysis resulted in a score, which allowed to classify 90% of the women with mamma carcinomas and 92% of the controls correctly. The possible application of this passive diagnostic method to the early detection of malign tumors in the breast is discussed.

Adult↗
PubMed2006

Field and laboratory evaluation of diagnostic assays for detecting West Nile virus in oropharyngeal swabs from California wild birds.

Three diagnostic assays for detecting West Nile virus (WNV) in avian oral swabs were evaluated in California in 2004 and 2005: two commercial antigen-capture assays, VecTest and Rapid Analyte Measurement Platform (RAMP), and reverse transcriptase-polymerase chain reaction (RT-PCR) of oral swabs in a specialized viral transport medium (VTM). Results from this study demonstrated that VTM was excellent for transportation and maintenance of WNV in avian oral swab samples and allowed for detection by RT-PCR and subsequent confirmation by virus isolation. Oral swabs and kidney tissue in VTM tested by RT-PCR were found to have similar accuracy in detecting WNV in corvids. The two antigen-capture assays, VecTest and RAMP, provided few false positives for corvids, with over 95% specificity. When performed by multiple local agencies throughout the state, VecTest and RAMP were similarly sensitive for oral swabs of American Crows (Corvus brachyrhynchos) (70% and 64%, respectively). Data from known WNV positive corvid oral swabs in VTM tested by antigen-capture assays at a diagnostic laboratory suggested that RAMP was more sensitive than VecTest. Due to high probability of false negatives, neither test is recommended for use on non-corvids. While WNV antigen-capture assays were effective screening tools for corvids, they were markedly less sensitive for Western Scrub Jays (Aphelocoma californica).

Animals↗
PubMed1991

The polymerase chain reaction: a new tool for the understanding and diagnosis of HIV-1 infection at the molecular level.

The polymerase chain reaction (PCR) is at present the most powerful analytical tool for detection of specific nucleic acid sequences. The method is based on the in vitro amplification of DNA segments before detection with conventional hybridization techniques or visualization following electrophoresis and staining. The current diagnostic methods for HIV-1 do not allow easy identification of subgroups of infected patients including infants born to seropositive mothers, individuals with delayed serological responses to the virus, infected patients with indeterminate serology results, and patients with dual retroviral infections. Furthermore, response to antiviral therapy cannot be evaluated with serological assays. The rationale for applying PCR in those situations is elaborated here. The applications of this technique for HIV-1 as a diagnostic test and for the understanding of the pathogenesis of this retrovirus are described. Potential limitations of this technique for diagnostic purposes include mainly the possibility of false-positive results due to contamination and false-negative reactions caused by Taq polymerase inhibition. Non-isotopic means for detection of amplified products have been described and should allow for a wider application of this technology. Modifications of PCR which make use of internal standards seem promising for quantitative analysis of nucleic acids. PCR has great potential for viral diagnosis but still requires further studies and better characterization.

Acquired Immunodeficiency Syndrome↗
PubMed1997

A multicentre quality assessment study to monitor the performance of HIV-1 PCR.

Eleven German laboratories and one Swiss laboratory initiated a quality assessment study to evaluate the specificity and sensitivity of their polymerase chain reaction (PCR) for detection of HIV-1 DNA. Following its own PCR protocols, each laboratory tested a panel of ten coded samples consisting of cell pellets containing 0, 0.1, 1, 10, 10(2), 10(3) and 10(4) ACH-2 cells per 1.5 x 10(5) uninfected peripheral blood mononuclear cells. Of the twelve participating laboratories, three reported correct results for the dilution series as well as for uninfected specimens. One or more classification errors were recorded for 12% of the samples for which the diagnosis was expected to be positive or negative. Samples containing 10 copies of the target template were correctly reported by eleven of the twelve participants. The average sensitivity was 97%. The results of the study revealed no significant differences between the Amplicor kit and in-house procedures. Most of the classification errors occurred in specimens from HIV-negative samples. Out of 36 negative samples, 5 were reported false positive, showing that contamination remains a problem for some laboratories, regardless of the PCR test performed. Careful laboratory techniques and internal as well as external quality control procedures will help avoiding carryover contamination.

DNA, Viral↗
PubMed1996

[The computed tomography of acute sigmoid diverticulitis].

PURPOSE: To study the ranking of CT in the diagnosis of sigma diverticulitis. Comparison of results of the colon monocontrast enema with those obtained via CT and histopathology as gold standard. MATERIAL AND METHODS: 32 patients were included who were operated on for sigma diverticulitis. In 30 patients both CT and monocontrast enema were performed and in two patients CT only. RESULTS: Acute inflammatory wall alterations are identified by CT with a sensitivity of 89.7% vs 96.3% via contrast enema. Pericolic reactions of the environment were seen via CT with 89.7% sensitivity. In case of covered perforations CT yielded a sensitivity of 76.5% vs 46.7% via contrast enema. Sensitivity for abscesses and fistulas was in each case 100% with CT. RESULTS: CT may help to identify extraluminal inflammatory changes and complications in diverticulitis. The degree of the inflammation can be classified and the surgical approach suitably influenced, respectively modified.

Acute Disease↗