[Infection of the athymic rat by Toxoplasma gondii].

In contrast to normal rats which are resistant to T. gondii infection (10(7) tachyzoïtes), athymic rats did not survive an intraperitoneal infection with 10(3) toxoplasma. When nude rats were injected intravenously with lymph node cells from hirsute littermates, they became resistant in a dose-dependent manner to the infection.

Light and electron microscopic study of cyclosporin A-induced gingival hyperplasia.

Four transplant (3 kidney, 1 bone marrow) patients with cyclosporin A (CyA)-induced gingival hyperplasia are described. Light and electron microscopic findings of gingival biopsies showed in all patients that, in addition to an increase of collagen, CyA induced in the subepithelial space an enormous infiltration of morphologically normal plasma cells in different stages of maturation. These data, together with the reversibility of the lesion upon discontinuation of the drug, suggest that individual hypersensitivity is probably the most acceptable explanation of CyA-induced gingival hyperplasia.

The immunodominant epitope of the major membrane tachyzoite protein (P30) of Toxoplasma gondii.

Several physicochemical characteristics of the repeated epitope of the major surface protein (P30) of Toxoplasma gondii were investigated with an anti-P30 mAb by two different methods: a one-site/inhibition assay that detects molecules containing single or multiple epitopes and a two-site/one antibody radiometric assay that is only effective with antigenic molecules containing two or more identical epitopes. Using both techniques, the repeated epitope within purified P30 was stable after 1 h at 63 degrees C, but labile at 100 degrees C. It was also resistant to successive freezing and thawing, and not affected after one year at -70 degrees C.

[A new ELISA method for the diagnosis of toxoplasmosis. Assay of serum IgM by immunocapture with an anti-Toxoplasma gondii monoclonal antibody].

The diagnosis of acute toxoplasmosis is based exclusively on the detection of IgM anti-Toxoplasma antibodies. The principal of the immunoenzymatic test reported here is the capture of serum IgM antibodies which are detected indirectly by the sequential addition of antigen and a monoclonal antibody directed against the immunodominant epitope at the surface of the tachyzoite. This test combines the sensitivity of enzyme-based assays and the specificity of monoclonal reagents and represents an important contribution to the diagnosis of Toxoplasma gondii infection.

[A new agglutination reaction for the diagnosis of the developmental stage of acquired toxoplasmosis].

Agglutination of acetone treated toxoplasma (AC) is different from that one of formalin fixed parasites (HS). Sera from patients with a recently acquired ("acute") infection agglutinate both HS and AC parasites suspensions as well; contrary to sera from patients with past infection ("chronic stage") in which high titers of HS agglutination are often present, while the titres of AC agglutination are lower even negative. This is markedly observed in patients with local lesions (relapsing chorioretinitis, patients with AIDS and brain abscesses).

Water and exchangeable sodium in Goldblatt two-kidney, two-clip hypertensive rats.

Exchangeable 22Na (ExNa), total body water (TBW) and the inulin space (InSp) were determined in two-kidney, two-clip (2K-2C) hypertensive and sham operated (normotensive) control rats 6-8 weeks after surgery. TBW (ml/kg lean body weight) was the same in hypertensive and sham rats. In contrast, ExNa (mEq/kglbw) and InSp (ml/kglbw) significantly increased (p less than 0.

Cavernous transformation of the portal vein: sonographic and computed-tomography findings.

A case of cavernous transformation of the portal vein detected by sonography and computed tomography is presented.

[Hypocomplementary membrano-proliferative glomerulonephritis in a Malagasy patient with schistosomiasis mansoni (detection of bilharzial antigen on glomerular basement membrane using monoclonal antibodies)].

Schistosomiasis due to Schistosoma mansoni affects more than 40 millions people all over the world. Renal involvement is observed mainly in endemic areas. We report a case of hypocomplementemic membrano-proliferative glomerulonephritis in a malagasy man who suffered also from hepatosplenic bilharziosis.

Serodiagnosis of toxoplasma infection using a purified parasite protein (P30).

The major surface protein (P30) of Toxoplasma gondii has been purified by immunoabsorption with anti-P30 monoclonal antibodies linked to a glutardialdehyde activated affinity absorbant. SDS-PAGE analysis of the eluted material followed by silver staining showed only a single band of 30,000 mol wt. Western blotting using antibodies from a rabbit immunized with purified P30 against the total Toxoplasma extract separated by SDS-PAGE again revealed an unique antigen of 30,000 daltons.

Use of a monoclonal antibody in a double-sandwich ELISA for detection of IgM antibodies to Toxoplasma gondii major surface protein (P30).

A double-sandwich ELISA, developed for detection of IgM antibodies to the major surface protein of Toxoplasma gondii (P30), is proposed for the diagnosis of acute acquired toxoplasmosis. The method is based on the capture of serum IgM antibodies, which are revealed indirectly by the sequential addition of a Toxoplasma extract and a beta-galactosidase-conjugated anti-P30 monoclonal antibody. All 57 patients tested with serological characteristics of recently acquired toxoplasmosis showed high levels of IgM anti-P30 antibodies.

Subspecies-specific surface antigens of promastigotes of the Leishmania donovani complex.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns of proteins and externally exposed labeled surface constituents were analyzed in promastigotes of three etiological agents of kala azar (Leishmania donovani, HS70 strain from India; L. chagasi, Imperatriz strain from Brazil; L. infantum, ITMPA K263 strain from Morocco and MO strain from France).

Major surface protein of Toxoplasma gondii (p30) contains an immunodominant region with repetitive epitopes.

Four monoclonal antibodies (mAb) against surface antigens of tachyzoites of Toxoplasma gondii were produced. Immunoprecipitation of extracts of 125I-labeled tachyzoites identified the same polypeptide with apparent molecular weight of 30 000 (p30). A competition binding assay indicated that a single region of p30 was recognized by all 4 of the mAb.

Differentiated microdomains of the luminal plasmalemma of murine muscle capillaries: segmental variations in young and old animals.

We investigated the luminal surface of the continuous endothelium of the microvasculature of the murine heart and diaphragm to find out whether it has differentiated microdomains. The probes were ferritin molecules, cationized to pI's 6.8, 7.

In vitro production of different interferon types by cloned human NK cells.

Human peripheral blood null cells were conjugated in vitro with K-562 cells and expanded into continuous cell lines using IL-2 containing medium (CM) and periodical restimulation with phytohaemagglutinin (PHA). Most of these lines were made up of granular blasts expressing high natural killer (NK) activity. When analysed for different surface markers, the large majority of the blasts were E rosette+, T3+, Tac+, DR+, Leu7+ with a variable proportion of cells expressing T8 and M1 antigens (range: 20-80%).

Effect of captopril on Na-K ATPase and Mg ATPase activities of erythrocyte ghost membranes.

Captopril has a known hypotensive action derived from the inhibition of the converting enzyme (Kininase II). To investigate whether other mechanism may contribute to vasodilation, Na-K ATPase and Mg ATPase activities on ghost red blood cells membranes were examined in the presence of the drug. The results show a stimulation of Mg ATPase activity and an inhibition of Na-K ATPase activity in a concentration dependent manner.

Infectivity of Leishmania promastigotes is associated with surface antigenic expression.

Differentiation between a non-infective and an infective Leishmania promastigote population was demonstrated. Promastigotes in the stationary phase (day 5) were found to be highly infective in vitro to BALB/c mouse peritoneal macrophages, compared with those of the logarithmic phase (day 3). The infective promastigotes showed surface antigenic determinants different from non-infective ones.

Prostacyclin (PGI2) synthesis in the vascular wall of rats with bilateral renal artery stenosis.

The ability of vessels (rings of arteries and vena cava) to synthesize prostacyclin (PGI2) "in vitro" was analyzed in the initial (6-day) and chronic (6-week) phase of two-kidney, two clip hypertension. Male Wistar CHbb THOM rats were used. Tissues were incubated for two hours in Krebs solution containing 14C-arachidonic acid as exogenous substrate.