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C E Farshy

Publications and source records attributed to C E Farshy.

27 records · Page 2Linked to original sources

Measure of immunoglobulin G-, M-, and A-specific titers against Legionella pneumophila and inhibition of titers against nonspecific, gram-negative bacterial antigens in the indirect immunofluorescence test for legionellosis.

A crude extract of Escherichia coli O13:K92:H4 inhibited 97% of positive indirect immunofluorescence titers against a variety of gram-negative bacterial antigens while lowering Legionella pneumophila titers in only 6% of sera from patients with suspected legionellosis. Legionella-specific titers were the result of immunoglobulins G, M, and A, singly or in combination.

Antibodies, Bacterial↗

Detection of Legionella pneumonophila antigen in urine by enzyme-linked immunospecific assay.

An enzyme-linked immunospecific assay "sandwich" technique was developed for detecting soluble antigen from the Legionnaires disease bacterium (Legionella pneumophila). With this technique, antigen was detected in urine specimens from guinea pigs inoculated intraperitoneally with heat-killed Legionnaires disease bacteria and in urine specimens from three of four patients who attended the American Legion Convention in Philadelphia in 1976. Urine from a fifth pneumonia patient who attended the Eucharistic Congress (but who was a dubious seroconverter) was negative. Presumably, the test could also be used for detecting antigen in sputum or respiratory aspirates, but this has not been tried to date.

Animals↗

Detection of antibodies to legionnaires disease organism by microagglutination and micro-enzyme-linked immunosorbent assay tests.

Microagglutination and micro-enzyme-linked immunosorbent assay (ELISA) tests with easily prepared, safe, heat-killed antigens for detecting antibodies to the legionnaires disease organism have been developed. A safranin-stained whole-cell antigen is used in the microagglutination test, and a simply prepared soluble antigen is used in the micro-ELISA tests. The microagglutination test detected elevated titers in 97.2% of the sera from patients with legionnaires disease. Three variations of the micro-ELISA test with anti-human immunoglobulin G, immunoglobulin M, and Fab peroxidase-labeled conjugates revealed elevated titers with 74.3, 82.9, and 88.6% of the sera, respectively. The microagglutination and the micro-ELISA tests used in combination detected 100% of the elevated titers.

Agglutination Tests↗

The relationship of race, sex, and age to concentrations of serum immunoglobulins expressed in international units in healthy adults in the USA.

Only a few investigations have been made to obtain human serum immunoglobulin values in units compatible with those used by the WHO International Reference Preparation for the Human Immunoglobulins IgG, IgA, and IgM. We report our summary statistics of serum IgG, IgA, and IgM, in international units (IU), for some 800 healthy American adults grouped by age, sex, and race. Our findings are in general agreement with some, but not with all, published data. We found that the mean IgG concentration is markedly higher and the mean IgA concentration is slightly higher in blacks than in whites. Except for white females, there was a significant increase in mean IgA with age for both races. In the younger adults of both races, mean IgM values were markedly higher in females than in males. Statistically significant interactions between race, age, and sex factors were seen for all three immunoglobulin classes. Although we have attempted to estimate the normal population means and variances for the serum concentration of IgG, IgA, and IgM the process we used to select specimens may have resulted in some bias; much larger, truly randomized, and fully documented studies in different geographic areas and in different socioeconomic and racial groups are needed to provide accurate acceptable limits for human immunoglobulins.

Adult↗

Staining intensities in the fluorescent treponemal antibody-absorption (FTA-Abs) test: association with the diagnosis of syphilis.

In 1984 the reporting system for the fluorescent treponemal antibody-absorption (FTA-Abs) test was changed by the Centers for Disease Control (CDC; Atlanta, GA) to eliminate the borderline report. Factors influencing the reliability of the FTA-Abs test results, i.e., sensitivity, specificity, prevalence of syphilis, prescreening of sera with nontreponemal tests, and reproducibility, were considered before the change in the reporting system was recommended and are reported here. The borderline report, when associated with syphilis, was most frequently also associated with the diagnosis of early primary, dark-field-positive, nontreponemal test-nonreactive syphilis. Whereas elimination of the borderline report decreased the sensitivity of the FTA-Abs test as a confirmatory test from 100% to 99.5%, the specificity increased from 82.5% to 88.7%. The 1+ staining intensity had an association of approximately 5% with the diagnosis of syphilis. The changes in the reporting system were designed to assist the clinician in interpreting the results of the FTA-Abs test in those cases that present diagnostic dilemmas.

Fluorescent Antibody Technique↗

Four serologic tests for syphilis: results with comparison of selected groups of sera.

The specificity of the fluorescent treponemal antibody-absorbed (FTA-Abs) test was assessed for 17 sera from syphilitic patients that were nonreactive in the Treponema pallidum immobilization (TPI) test but reactive in the FTA-Abs test. Thirty-three other sera from syphilitic patients and 19 sera from nonsyphilitic individuals were also examined by fluorescent treponemal and microhemagglutination Treponema pallidum (MHA-TP) tests and by the enzyme-linked immunosorbent assay (ELISA). Specific absorptions of sera with calf thymus DNA or Treponema pallidum biotype Reiter (Reiter treponemes) were performed. In quantitative immunofluorescence assays (IFA) with antihuman IgG and IgM conjugates, results were similar to those for reactive sera from a control group. Results of both the MHA-TP and ELISA tests supported the specificity of the FTA-Abs test; reactivity in the latter was not removed by specific absorption either with calf thymus DNA or with Reiter treponemes. This evaluation suggests a format for serodiagnosis in cases in which test results are discrepant.

Enzyme-Linked Immunosorbent Assay↗

Evaluation of sera from patients with Lyme disease in the fluorescent treponemal antibody-absorption test for syphilis.

To determine whether the cross-reactivity between Treponema pallidum and Borrelia burgdorferi affects the specificity of the fluorescent treponemal antibody-absorption (FTA-Abs) test for syphilis, sera from patients with Lyme disease or syphilis were examined in a quantitative FTA-Abs test. Sera were diluted serially in phosphate-buffered saline, then in sorbent, and were tested with T. pallidum and B. burgdorferi antigens. Nine of 40 sera from patients with known Lyme disease were reactive at the 1:5 dilution with antigen from T. pallidum; only one serum was reactive at the 1:10 dilution. When both antigens were tested, the titer against B. burgdorferi was always higher than that against T. pallidum. Similarly, sera from patients with syphilis showed cross-reactivity with B. burgdorferi. Although reactivity could be absorbed with Treponemal phagedenis (Reiter strain), simultaneous titration with both antigens was easily performed and designated the etiologic agent.

Antigens, Bacterial↗