Application of fluorescent-antibody (FA) techniques to the study of rhizobia as free-living soil bacteria was explored. Antiserum to a particular strain of Rhizobium japonicum proved specific in both agglutination and FA tests. Within the R. japonicum group, 2 of 12 strains were stained by the conjugate and these fluoresced brightly; all others were entirely negative. FA tests were negative for 7 strains of R. meliloti, 9 strains of R. leguminosarum, 9 strains of R. trifolii, 6 strains of R. phaseoli, and 65 unidentified bacteria isolated from 12 soils. R. japonicum grew in autoclaved soil and was readily detectable by FA examination of contact slides. The FA technique also detected antibody-reacting bacteria in a field soil whose rhizobial content was unknown. Fluorescent cells were probably R. japonicum, since nodules developed on soybean plants grown in the same soil sample and FA preparations of the crushed nodules proved positive. Autofluorescence was not a problem, but nonspecific adsorption of conjugate restricted observations to microscopic fields free from soil particles. Nonspecific adsorption was substantial, irrespective
Strains of Aspergillus flavus grown in soil in the presence of buried slides could be detected on the slides by fluorescent antibody techniques. Staining with A. flavus antiserum labeled with fluorescein, followed by examination with fluorescence microscopy revealed characteristic fluorescence at sites of distribution of the homologous fungus. The specificity of the reaction and the absence of nonspecific absorption of antibody to soil materials suggest that the method may be useful in studying the ecology of the soil microflora.
A patient with Hodgkin's disease is described who developed chronic myelogenous leukemia 8 1/2 years after the start of radiation therapy. This therapy was fractional and was administered to most of the patient's skeleton. The radiation was an important factor in the development of leukemia. The presence of positive reactions to the antileukemic fluorescent antibodies may be consistent with the hypothesis that viruses are concerned with human leukemia.
Plasma obtained from patients with leukemia, was concentrated by high speed centrifugation and used to prepare antisera in rabbits. Unabsorbed, anti-human leukemia plasma and anti-murine leukemia virus (Rauscher) anti-sera showed similar immunofluorescence with normal and leukemia leukocytes. After absorption of these antisera with normal human antigens, normal cells were non-reactive and leukemia cells still reactive. Each antisera was shown to contain antibodies capable of cross reacting with and/or blocking the immunofluorescent reaction of cells from acute myelogenous, stem cell, or lymphatic leukemia cases. Pre-immunization rabbit serum and anti-human normal plasma antisera failed to show these reactions. These and antisera to other antigens (human globulin, Herpesvirus, adenovirus) were also non-reactive with acute phase leukemia cells. Such findings indicated a specificity for human leukemia cells by the described antisera and that human leukemia cells and Rauscher murine leukemia virus may have common antigens. Serial studies on leukemia patients showed that the number and intensity of fluorescing cells varied with the clinical state of the patient. The three antisera gave similar reactions in acute leukemia. Differences were noted in remission. It was postulated that these differences were due to other cellular antigens, masked during the acute phase reaction. Leukocytes from patients with Hodgkin’s disease, lymphoma(s) and multiple myeloma also showed fluorescence when reacted with anti-murine leukemia. (Rauscher) virus anti-serum. Whether this common antigenicity with leukemia cells indicates similar altered cell growth and/or related etiology remains unresolved.
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