Biomedical subjects

E Krambovitis

Publications and source records attributed to E Krambovitis.

26 records · Page 2Linked to original sources

PubMed1993

Development of a direct and specific enzymeimmunoassay for the measurement of oestrone sulfate in bovine milk.

A 12-step procedure is described for the synthesis of an oestrone-3-sulfate-6-hemisuccinate-BSA immunogen with oestradiol as starting material and the production of specific polyclonal antibodies. A competitive inhibition-type enzymeimmunoassay has been developed based on these specific antibodies using 3-hemisuccinate-oestrone-peroxidase as conjugate for direct measurement of the hormone in body fluids. The method has a minimum sensitivity of 0.03 ng ml-1 in bovine milk, and satisfactory specificity, recovery and reproducibility. In a small field trial with a group of 20 pregnant cows that were followed throughout gestation, it was shown that the assay is potentially an accurate pregnancy test for assessing the viability of the fetoplacental unit at approximately 100 days after insemination. The assay is well suited for routine testing, particularly as a confirmatory bovine pregnancy test.

Animals↗

PubMed1992

A simple enzyme immunoassay for detecting brucellosis antibodies.

A simple enzyme immunoassay was developed and evaluated for serological diagnosis of brucellosis in 25 patients with various forms of brucellosis and 292 control patients with other conditions and disorders. All brucellosis patients gave a positive test with the initial sample. In 3 acute, febrile brucellosis patients with follow-up sera taken during therapy a sharp drop in specific antibody was noted. There was a less pronounced antibody reduction in 1 chronic and 2 relapse patients and an antibody increase in 1 chronic and 1 relapse case. All control samples gave negative results. In addition, the assay was evaluated as a screening test with 315 sera from 'healthy' individuals living in a brucellosis focus and representing 15% of that population. 11.5% (34/293) of subjects with no reported history of brucellosis and 45% (10/22) of cases treated in the past gave a positive test result. The agreement in those samples between the assay and the serum agglutination test was 95.5%.

Adolescent↗

PubMed1987

Murine monoclonal antibodies for detection of antigens and culture identification of Neisseria meningitidis group B and Escherichia coli K-1.

Four murine monoclonal antibodies which reacted with a (2----8)alpha-linked sialic acid polysaccharide were produced. Three of the antibodies reacted specifically with Neisseria meningitidis serogroup B and Escherichia coli K-1 polysaccharide antigens, whereas one antibody cross-reacted with N. meningitidis group C polysaccharide antigen, a (2----9)alpha-linked homopolymer of sialic acid. By using the most avid antibody (MB 62), a latex particle agglutination test was developed which could detect capsular polysaccharide at 10 ng/ml. It also detected antigen in the cerebrospinal fluid (CSF) of all seven N. meningitidis group B- and two E. coli K-1-infected patients, whereas 57 control CSF samples, including 8 from neonates, were negative. Cultures of 21 N. meningitidis group B strains, 7 E. coli K-1 strains, and 1 Moraxella nonliquefaciens strain gave a positive result, whereas 53 strains from other serogroups were all negative. In a separate clinical evaluation, the overall sensitivity of the latex particle agglutination test was 81% (22 of 27) with fresh CSF samples, 48% (15 of 31) with stored CSF samples, and 94% (32 of 34) with blood cultures. No false-positive reactions were recorded with 165 control CSF samples, and the specificity with blood cultures was 99.4% (519 of 522).

Agglutination Tests↗

PubMed1986

Detection of antibodies to Mycobacterium tuberculosis plasma membrane antigen by enzyme-linked immunosorbent assay.

Antibody activity against Mycobacterium tuberculosis of sera from an area with a high prevalence of tuberculosis was measured by enzyme-linked immunosorbent assay (ELISA) with a plasma-membrane extract from M. tuberculosis strain H37RV. All sera from relapsed tuberculosis patients and 82.5% of sera from new untreated cases gave positive results. The seronegative group of tuberculosis patients gave positive results by direct microscopy and culture. No clear correlation between antibody and delayed hypersensitivity or extent of disease was observed. Chemotherapy was associated with a higher antibody response. Specificity of the test with healthy control subjects from the high prevalence area was 85%. Negative results were obtained with 145 sera from presumed healthy European subjects and with seven sera from BCG-vaccinated subjects.

Adult↗

PubMed1986

Improved serodiagnosis of tuberculosis using two assay test.

An antigen capture immunoassay was developed for the detection of mycobacterial antigens in sera from patients with tuberculosis. The assay was evaluated together with an antibody measuring enzyme immunoassay in a clinical trial for serodiagnosis of tuberculosis. Sensitivity of the antibody assay for active pulmonary tuberculosis, including relapsed infections, was 75%, and specificity with other lung diseases was 97%. Sensitivity for extrapulmonary tuberculosis was 84.5% and specificity 84%. Sensitivity of the antigen assay for active tuberculosis was 45% with no false positive reactions. Combination of the results from the two assays increased total sensitivity to 96.5% with a positive predictive value of 0.81 and a negative value of 0.98. The two assay test was relatively simple to perform and offered improved serological diagnosis of tuberculosis over a single antibody test.

Adult↗

PubMed1984

Rapid diagnosis of tuberculous meningitis by latex particle agglutination.

A simple latex particle agglutination test for the rapid detection of Mycobacterium tuberculosis plasma membrane antigen in cerebrospinal fluid was evaluated in 18 children with tuberculous meningitis and 134 control children with other disorders. The antigen was detected in all 18 patients with tuberculous meningitis, although an initial sample from 1 patient did not contain detectable antigen before it was concentrated. 133 of 134 control samples gave negative results.

Antigens, Bacterial↗

PubMed1983

Evaluation of a monoclonal antibody (TB72) based serological test for tuberculosis.

A serological test for tuberculosis (TB), based on competitive inhibition by human sera of antigen binding by a murine monoclonal antibody (TB72) has been performed using solid phase radioimmunoassay. The test was evaluated on sera from patients with pulmonary or extra-pulmonary active TB as well as from control hospitalized patients--half of whom had various chest complaints. Positive values were found in 74% of all or 55% of untreated active pulmonary TB. Patients with extrapulmonary TB segregated, whereby antibody titres were increased in cases of pleural, peritoneal, pericardial or bone infection but only marginal or negative values were found in the majority of patients with lymphatic and genitourinary infection. None of the subjects with suspected but excluded tuberculosis or sarcoidosis had demonstrable TB72 antibodies. Generally there was a positive correlation between the levels of TB72 like and 'total' Mycobacterium tuberculosis sonicate binding antibodies. In particular, the titre of sonicate binding antibodies did not exceed background levels in patients with active pulmonary tuberculosis who were negative in the TB72 competition test. None of these false negative patients received drug therapy whereas most patients with the highest antibody levels were under chemotherapy for 1-8 months prior to serum testing. The serodiagnostic value of the TB72 based competition test has been discussed.

Adult↗

PubMed1980

Assessment of the tuberculosis agglutination test.

A total of 139 random samples of serum taken at intervals during chemotherapy from 16 patients were analysed using agglutination methods for the serological diagnosis of tuberculosis. The series comprised six cases of far advanced pulmonary tuberculosis, four cases with advanced lesions, two cases with minimal spread and four controls. The samples were analysed simultaneously and independently using two different batches of antigen in two test systems. The test results were comparable in the two series and the diagnostic outcome of the test was not encouraging, the percentages of false negatives being 52 and 60 or 9 and 32, depending on the criteria selected, and those of false positives being 3 and 0 or 59 and 44 respectively. The magnitude of the titres obtained did not reflect the severity of the disease. In addition the test did not prove useful as a method for following up the results of treatment of individual patients in this series.

Agglutination Tests↗