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Biomedical subjects

H Russell

Publications and source records attributed to H Russell.

49 records · Page 3Linked to original sources

Capillary precipitin typing of Streptococcus pneumoniae.

The Neufeld test is presently the method of choice for typing Streptococcus pneumoniae. Although the test is reliable and relatively easy to perform, a simpler test, not requiring microscopic examination, would facilitate large-scale testing. A capillary precipitine test has been designed and tested for its usefulness in typing pneumococci. The type-specific carbohydrate antigens were obtained from broth culture supernatants. The antigens were reacted with type-specific antisera in glass capillary pipettes. Results from 82 reference antigens and 166 antigens from diagnostic pneumococcal strains showed that the reactions ere specific, and the results agreed with Neufeld test results. These results indicate that the precipitin test is as specific as the Neufeld test. The test is easy to perform, requires small amounts of antiserum, and can be completed in a short period of time.

Humans↗

Enzyme-linked immunosorbent assay for streptococcal M protein antibodies.

The enzyme-linked immunosorbent assay (ELISA) described by Engvall and Perlmann, which uses antigen-coated tubes and enzyme-labeled anti-immunoglobulin, has been used for the detection of antibodies against streptococcal M protein. The antigen used in the assay was obtained by guanidine extraction of type M-12 streptococcal cell walls followed by hydroxyapatite chromatography. This antigen has the capacity to elicit bactericidal antibodies in rabbits. The results show that the ELISA is specific and highly sensitive for the detection of antibodies in rabbit and human antisera. Preliminary results suggest that, when M-12 antigen is used, the antibodies detected by ELISA are the same antibodies detected in the bactericidal test. The assay has been performed with human and rabbit sera. There was a 96% agreement between bactericidal and ELISA results with rabbit sera and 97.5% agreement with human sera. All bactericidal antibody-positive sera tested thus far yielded positive ELISA results.

Alkaline Phosphatase↗

Guanidine extraction of streptococcal M protein.

A new method of extracting M protein from streptococcal cell walls has been presented. The extracting agent was guanidine-hydrochloride, a protein denaturant. The crude guanidine extract was further purified by ammonium sulfate and pH 5 fractionation and by hydroxyapatite column chromatography. Three major protein peaks were eluted from the hydroxyapatite column with 0.01, 0.1 and 0.3 M phosphate buffer, respectively. Protein fractions eluted at 0.1 and 0.3 M phosphate concentractions contained antigens that precipitated with homologous M-protein specific antisera, whereas the 0.01 M phosphate fraction had no immunological activity. The fraction eluted with 0.3 M phosphate was electrophoretically homogeneous in sodium dodecyl sulfate-acrylamide gels and elicited the production of bactericidal antibodies in rabbits. The 0.1 M phosphate buffer eluant was electrophoretically heterogeneous and did not elicit the production of bactericidal antibodies in rabbits.

Animals↗

Separation of Treponema pallidum from tissue substances by continuous-flow zonal centrifugation.

The zonal ultracentrifuge was used for separation of Treponema pallidum from large volumes of rabbit testicular syphiloma extracts by continuous-flow centrifugation in a cesium chloride density gradient. The gradient was linear with radius from a density of 1.05 to 1.36 g/ml. Operating speeds were 15,000 rev/min for the continuous-flow phase and 25,000 rev/min for a 30-min banding period. A total of 9 x 10(9) (24.3%) treponemes were recovered from the original extract. Of the treponemes recovered, 88% formed a band at a density of 1.170 to 1.211 g/ml. Within the limits of present methods of assay, these fractions were relatively free from testicular particulates and protein when compared with treponemes recovered after differential centrifugation. Observations of the isolated fractions by dark-field and electron microscopy indicated a lack of gross morphological damage to T. pallidum. Their antigenic characteristics were also retained, as evidenced by their ability to react with syphilitic sera in the indirect fluorescent-antibody procedure.

Animals↗

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↗

Lyme disease surveillance in the United States, 1983-1986.

During 1983-1986, 5,016 cases of Lyme disease were reported to the Centers for Disease Control. Cases were acquired in 31 states; however, 86% of the cases were acquired in seven states: Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Wisconsin, and Minnesota. For 63% of patients the disease began in summer; 52% recalled a tick bite. Erythema chronicum migrans (ECM) occurred in 91% of the patients; arthritis, in 57%; neurologic complications, in 18%; and cardiac manifestations, in 10%. When serum samples were obtained greater than or equal to 21 days after onset of symptoms, 14% (6 of 42) with ECM alone and 19% (17 of 89) with complicated Lyme disease (ECM plus organ-system involvement) had positive serologic tests. Antimicrobial therapy did not appear to affect serologic response. Lyme disease is now the most commonly reported tick-borne illness in the United States and has been reported from 32 states since 1980. Physicians nationwide need to be familiar with the protean signs and symptoms associated with Lyme disease and with the limitations of current serologic techniques in diagnosing early illness.

Enzyme-Linked Immunosorbent Assay↗