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Biomedical subjects

F Boulanger

Publications and source records attributed to F Boulanger.

8 recordsLinked to original sources
PubMed1994

Toxoplasma gondii-structure variations of the antigen P30.

The major surface immunodominant antigen (P30) of Toxoplasma gondii was purified by two methods (i) SDS-PAGE and (ii) immunoaffinity chromatography. The secondary elements within this protein were assessed by circular dichroism and spectra obtained were compared to those proposed by Manavalan & Johnson (1983). The results allowed us to determine an all beta protein status for this antigen. This experimental result was in agreement with the predicted secondary structures deduced from the P30 primary sequence. Modifications in conformation according to pH and temperature were recorded without any change in immunoactivity. The epitope, which was always recognized by a monoclonal antibody against P30, could be a linear epitope.

Amino Acid Sequence↗
PubMed1991

Quantitative immunolocalization of four immunodominant antigens of Toxoplasma gondii.

Ultrastructural localization of four immunodominant antigens of Toxoplasma gondii was investigated quantitatively on thin sections and replicas by an immunogold technique using four monoclonal antibodies (Mab). On immunoblot Mab IV47, GII9, II38 and IE10 identified proteins of 28, 30, 45 and 66-70 kDa, respectively. Use of digital image analyzer and a semi-automatic procedure developed by us, the patterns of label distribution were compared in three cell structures: cell surface, submembrane area and rhoptries. On the whole cell surface, protein P28 and P30 were 2.5 and 4 times more abundant than P66-70 respectively. The protein P28 was essentially concentrated in the submembrane area with a labeling of 195.4 +/- 46.7 gold particles/microns 2 that follows a decreasing gradient from this area to the cell centre. In the rhoptries, all four antigens were detected, P45 and P66-70 being major with a labeling of 97.1 +/- 31.1 gold particles/microns 2 and 155.1 +/- 39.3 gold particles/microns 2 respectively. The results support the hypothesis that rhoptries are the essential site for antigen storage.

Animals↗
PubMed1990

Toxoplasma gondii: immunocytochemistry of four immunodominant antigens with monoclonal antibodies.

Four monoclonal antibodies in which diagnostic usefulness has been observed, concerning congenital, acquired, and reactivated toxoplasmosis, were raised against Toxoplasma gondii tachyzoïtes in order to localize immunodominant antigens. On immunoblots, it appears that McAb IV47, McAB GII9, McAb II38, and McAb IE10 identify families of proteins with estimated molecular weights of 28-30 kDa, 30 kDa, 45-50 kDa, and 66-70 kDa, respectively. By immunogold preembedding techniques one can observe an homogeneous labeling of the outer pellicle of the tachyzoïtes with the McAb GII9 and IV47 and a light labeling with the McAb II38 and IE10. The three-dimensional observation of cell surface antigens is performed by applying a modified metal extraction replica method, i.e., A plasma polymerization method of glow discharge by Tanaka (1979). By immunogold preembedding techniques [with saponin permeabilization (0.1%)], and by immunogold postembedding techniques, a labeling of the rhoptries is observed with McAb GII9 and McAb IV47 but essentially all label is found with McAb II38 and IE10. With McAb GII9 a uniform labeling is observed on the cell surface. By immunoenzymatic techniques (peroxidase) a cell surface labeling is observed with the four McAb. Intracellular Toxoplasma, the outer pellicle, and the vesicles of the network (elaborated by Toxoplasma in parasitophorous vacuole) are also labeled with McAb IE10. These results indicate that McAb GII9 recognizes antigens of the antigen family (P 30) located on the cell surface and in the rhoptries. The antigen recognized by McAb IV47 is essentially located on and beneath the Toxoplasma cell surface membrane, and McAb II38 and IE10 identify preferentially rhoptry proteins.

Animals↗
PubMed1989

[Choice of antibiotics in periodontology].

For periodontal treatment, the use and choice of antibiotics is a controversial matter. There are many medical reasons for prescribing antibiotics before, during and after periodontal treatment. The purpose of this paper is to review the indications and reasons for antibiotherapy in periodontics. Research is not very advanced in this domain and there is a need to understand the indications for antibiotherapy in periodontics.

Anti-Bacterial Agents↗
PubMed1986

Multiple mutations in the transferred regions of the Agrobacterium rhizogenes root-inducing plasmids.

Agrobacterium rhizogenes induces root formation at the site of inoculation in plants and inserts fragments of its Ri plasmid into the plant nuclear DNA. The transferred region (T-DNA) of the Ri plasmid of the A. rhizogenes strain A4 is made of two fragments, namely TL and TR; the latter harbors a sequence homology with the tms loci (responsible for auxin synthesis) of A. tumefaciens. On Daucus carota slices, single insertion mutations on the TL region of A. rhizogenes do not confer a mutant phenotype while an insertion-deletion in the TR region do confer a Basatt phenotype. Six double mutants with a single insertion in the TL region and the same deletion-insertion of the TR region were constructed. Three of these double mutants were avirulent on D. carota which indicates that in A. rhizogenes A4 the TL and the TR regions cooperate to confer a full infectious phenotype.

DNA Transposable Elements↗
PubMed1986

A search for interstellar H3O+.

The P (2,1) line of H3O+, the hydroxonium ion, a key species in ion-molecule chemistry, has been sought in the interstellar medium and in Halley's Comet. In OMC1 and SgrB2, a line was detected which may possibly be attributed to H3O+. Verification of this identification must be accomplished through observation of the P(3,2) line at 364 GHz, or detection of isotopic variants. If we were to assume that the detected line arises from H3O+, we can deduce a fractional abundance X(H3O+) in OMC1 and SgrB2 of approximately 10(-9) and a production rate in Comet Halley of Q(H3O+) 10(28)s-1. These results would place H3O+ among the more abundant molecular ions in the interstellar gas in agreement with theoretical predictions.

Astronomical Phenomena↗