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STUDIES OF THE TREPONEMA PALLIDUM IMMOBILIZING ACTIVITY IN NORMAL HUMAN SERUM. I. A METHOD
Author(s) -
Hederstedt Bengt
Publication year - 1974
Publication title -
acta pathologica microbiologica scandinavica section b microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0365-5563
DOI - 10.1111/j.1699-0463.1974.tb02311.x
Subject(s) - treponema , ionic strength , chemistry , in vitro , reaction rate , chromatography , biochemistry , immunology , biology , syphilis , catalysis , organic chemistry , human immunodeficiency virus (hiv) , aqueous solution
Taking advantage of the experiences gained with the TPI‐test ( T. pallidum immobilization reaction by immune serum), a method for quantitation of T. pallidum immobilizing activity in normal unheated human serum was developed on the basis of the kinetics and optimal conditions of this normal serum reaction in vitro. Some experiments concerning factors influencing the haemolytic complement activity (e.g. the SH‐compounds of the TPI‐test medium) as well as the treponemal survival were also presented. As compared with the immune serum reaction, the normal serum reaction had a much shorter lag phase; at high serum concentrations it was not measurable, i.e. <10 minutes, and the reaction rate was faster, the reaction being almost completed within two hours. The length of the lag period increased with treponemal concentration and decreased with temperature. The reaction rate after the lag period appeared to be influenced only to minor degree within certain ranges, either by concentrations of serum or by the concentration of the treponemes. The temperature coefficient (Q 10 ) was found to range around two to three. The normal serum reaction was dependent on the ionic strength, being enhanced below and depressed above the ionic strength of 0.15. The optimal pH, tested within the range 6.8–7.8 was found to be 7.2–7.8. Mg++, in contrast to Ca++, had an enhancing effect on the normal serum activity, the optimal final concentration of Mg++ ranging around 0.005 M. The normal serum immobilization reaction resembled in many respects the bactericidal and bacteriolytic reactions to be evoked by normal serum.