Biomedical subjects
Publications and source records attributed to S Stadtsbaeder.
Fourteen cases of Lyme arthritis are reported. The most frequent picture was that of oligoarthritis appearing in that part of the leg where the cutaneous or neurological complications, or both, of Lyme disease had developed before the arthritis. In most cases recovery followed a single 10 day course of intravenous (IV) penicillin therapy. Arthritis was the presenting feature of Lyme disease in three cases.
An indirect enzyme-linked immunosorbent assay (ELISA) using the six serogroups of whole L. pneumophila bound to microtitre plate wells is described for the serodiagnosis of legionellosis. Comparative studies using monovalent antigen indicated a high correlation between ELISA and indirect immunofluorescence antibody (IFA) tests (r = 0.90, P less than 0.001). Testing 196 human sera by ELISA using both monovalent and polyvalent antigens have established the efficiency of the polyvalent antigen for screening purposes. The ELISA test system exhibited rapidity, sensitivity and reproducibility and should be considered as an alternative to the IFA test for routine serodiagnosis of legionellosis.
An indirect ELISA using whole tachyzoites of Toxoplasma gondii fixed onto the bottom of microtiter plate wells is described for detection of specific G and M anti-toxoplasma antibodies. ELISA results were compared with those of IFA and IHA tests. Similarity of antigens (cell surface) involved in ELISA and IFA permits high correlation between the two tests (r = 0.84-0.93, P less than 0.001) and results in good accordance for negative sera. As ELISA offers several advantages over the classical IFA test, it may be considered an alternative method for screening of G and M anti-toxoplasma antibodies.
The double-sandwich enzyme-linked immunosorbent assay has been compared with the indirect fluorescence assay for the detection of immunoglobulin M antibodies against Toxoplasma gondii in humans. Incubation times have been shortened, permitting the test to be completed within 2 h. The double-sandwich enzyme-linked immunosorbent assay is confirmed to be more sensitive and more specific than the immunofluorescence assay.
Monolayers of pneumococcus (serotype 27) on flat bottom polystyrene microtiter plates were used as a solid phase sorbent for the determination of C-reactive protein (CRP) by ELISA. After binding to the monolayer, CRP was quantified with peroxidase conjugated rabbit anti-human CRP immunoglobulin. The method is sensitive (5 micrograms/ml), rapid (less than 2 h) and correlates well with a laser nephelometric assay (r = 0.95, P less than 0.001), and with a classical sandwich ELISA (r = 0.95, P less than 0.001).
The effects of cotrimoxazole (CTX) and spiramycin (Spir) in mice infected in midpregnancy with the Beverley (Bev) strain of Toxoplasma gondii were compared. Therapeutic effectiveness was determined according to the following parameters: rate of successful delivery, litter size, offspring weight and survival. When compared with the uninfected untreated control group, CTX showed a more beneficial therapeutic effect than Spir, with a statistically significant increase in the rate of both successful delivery and offspring survival. Results based on antitoxoplasma antibody determinations in the offspring indicated a better in utero control of congenital infection by CTX than by Spir.
The mode of entry of living trophozoites of Toxoplasma gondii (RH strain) into normal mouse peritoneal macrophage and HeLa cell monolayers was studied by phase-contrast microcinematography. The results have shown that Toxoplasma can enter into macrophages either by phagocytosis (Figs. 1 and 2) and/or by active penetration (Fig. 3). Only the latter process was observed with normally non-phagocytic HeLa cells (Fig. 4). During this process the parasites actively moved towards the host-cells by flexion and penetrated them always through their sharpest end. Active penetration was a rapid phenomenon (about 20 s at 37 degrees C) and was accompanied by a series of morphological changes, i.e., elongation of the anterior end, contraction and swelling of the parasite body. Contrasting with phagocytosis, toxoplasmas which had penetrated into the cell were not immediately isolated from the host-cytoplasm by a microscopically discernable vacuole. The nature of the process of penetration (pressure and/or perforation of the plasma membrane) is discussed.
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Mouse peritoneal macrophages, but not HeLa cells, presented many characteristics of activated cells following treatment in culture with LTN or PSK. Indeed, they demonstrated increase in size, spread, endocytic and antiparasitic activities. These data lead favorably to consider that among the five polysaccharides tested under the present experimental model LTN and PSK are the most potent activators of resident mouse peritoneal macrophages in vitro. The mechanism of macrophage activation by LTN and PSK should be different from that of Di Luzio glucans and SPG since activated macrophages can be induced by the latter two compounds in experimental animals but not in vitro in cell cultures.
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Ficoll-purified lymphocytes (peritoneal, splenic, or thymic) and macrophages (peritoneal) from Toxoplasma-immune and normal female NMRI mice were used. Suspensions of washed cells were made in medium 199 containing 20% heat-inactivated normal calf serum. Sixty minutes after the adherence of 10(5) macrophages to cover slips in Leighton tubes, lymphocytes were added in various concentrations. The mixed cellular population was then incubated at 37 C. Eighteen hours later, most of the lymphocytes were firmly attached to macrophages to form rosettes. This cellular interaction, which was temperature, cell ratio, and time dependent, occurred in the absence of any particular antigenic stimulation. Morever, the reaction was cytotoxic only for adhered lymphocytes as judged by staining with 0.2% trypan blue. Splenic and thymic lymphocytes were bound in significantly greater number than peritoneal lymphocytes. Incubation of macrophages for more than 48 h at 37 C before the addition of fresh lymphocytes markedly reduced rosette formation. Treatment of macrophages and lymphocytes with mouse anti-immunoglobulin did not affect the reaction. The labeling of lymphocytes with fluorescent anti-mouse sera and the use of nude NMRI mice showed that both B and T cells can form spontaneous rosettes with syngeneic peritoneal macrophages.
The appearance of transformed lymphocytes in the circulating blood of transplanted patients may easily be followed by examination of blood smears. There is a significant relationship between the number of peripheral lymphoblasts and the course of the graft. The reliability and specificity of the test are discussed.
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Cotrimoxazole, from 60 mug/ml, inhibited the replication of Toxoplasma gondii within Hela cells and mouse peritoneal macrophages. The percentage of inhibition reached practically 100% after 18 hours of treatment at 37 degrees C. More prolonged treatment resulted in an eradication of the organisms from the cell monolayers. In contrast, similar doses of spiramycin were quite ineffective against intracellular toxoplasma. The active doses of cotrimoxazole used were not harmful for cell cultures. Cotrimoxazole also destroyed clones (rosaces) of toxoplasma which were formed during the past 18 hours of intracellular replication in the absence of the drug. Trimethoprim was the only effective compound of cotrimoxazole on intracellular parasites; the adjunction of sulfamethoxazole produced a marked synergistic effect. The present findings confirm the great efficiency of cotrimoxazole in the treatment of experimental toxoplasmosis in mice performed previously in this laboratory.
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