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G Peltre

Publications and source records attributed to G Peltre.

At least 55 records · Page 3Linked to original sources
PubMed1994

Comparison of three horizontal two-dimensional electrophoretic techniques to separate grass pollen allergens.

The identification and characterization of allergenic components are important for improving both diagnosis and therapy of allergy. We have studied grass pollen crude extract for better characterization of the allergen repertoire recognized by allergic patient IgE antibodies. Two-dimensional electrophoresis are the methods of choice to define physico-chemical characteristics of the allergens as they give isoelectric points and molecular mass of the analyzed samples. We compared the advantages and the drawbacks of three different ways to perform a two-dimensional electrophoresis. First, two gel media were compared to run native isoelectric focusing (IEF) with carrier ampholytes: agarose and acrylamide. With the introduction of immobilized pH gradient, highly resolutive and reproducible 2D electrophoresis could be obtained. This technique was also applied to separate the allergens of Dactylis glomerata pollen.

Allergens↗
PubMed1993

Isotypic analysis of grass pollen-specific immunoglobulins in human plasma. 1. Specialization of certain classes and subclasses in the immune response.

The specificity and isotypic profile of humoral immune responses to Dactylis glomerata (Cocksfoot) pollen was studied by isoelectric focusing (IEF)-immunoprint analysis using 26 human plasma samples with high levels of Dactylis pollen-specific IgG4 (IgG4+ plasma) and 25 human plasma samples with low levels of specific IgG4 (normal plasma). Over 60 individual protein components in an aqueous pollen extract were separated by IEF and immunoprinted onto nitrocellose (NC). Following plasma incubation, bound IgE, IgG1-4, IgA1, IgA2 and IgM antibodies were detected on separate immunoprints with isotype-specific antibodies. Binding patterns of IgG4 and the majority of IgG1 and IgA2 antibodies in the IgG4+ plasma group very closely paralleled the binding patterns produced by the IgE antibodies from the same plasma and are described as the 'allergen repertoire'. In contrast, IgE, IgG4, IgG1 and IgA2 antibody reactivities to the 'allergen repertoire' were insignificant in the normal plasma group. These results suggest a qualitative, as well as a quantitative relationship between the immune responses which involve these 4 isotypes. Characteristic IgG2 and IgM antibody binding patterns, predominantly to non-allergenic antigens, were shared by the plasma from both groups, while IgG3 and IgA1 antibody binding patterns were highly variable from one plasma to another in both groups. One possible origin of the allergic diseases at the immunoglobulin heavy chain gene level is discussed.

Antibody Formation↗
PubMed1993

Isotypic analysis of grass-pollen-specific immunoglobulins in human plasma. 2. Quantification of the IgE, IgM, IgA class and the IgG subclass antibodies.

Previously, the specificity of human immune responses to Dactylis pollen was analyzed in 26 plasma samples with high levels of grass-pollen-specific IgG4 ('IgG4+ plasma', largely from grass-pollen-allergic patients), as compared to 25 plasma samples with low grass-pollen-specific IgG4 ('normal plasma', from nonatopic individuals). In the present study, a quantification of the Dactylis-pollen-specific IgE, IgM, IgA class and IgG subclass antibodies in these plasma samples is proposed. Isotypic distribution in IgG4+ plasma was 68% IgG [IgG2 (38%) > IgG4 (30%) > IgG1 (19%) > IgG3 (13%)], 27% IgM, 4% IgA and 0.05% IgE. In normal plasma it was 73% IgM, 20% IgG [IgG3 (38%) > IgG2 (33%) > IgG1 (29%) > IgG4 (0%)], 6% IgA and 0.006% IgE. In IgG4+ plasma, specific IgE, IgG1, IgG2 and IgG4 concentrations were positively correlated between each other. Finally, the present study clearly confirmed the possible role of the CH gene regulation in allergic diseases.

Gene Expression Regulation↗
PubMed1993

Two-dimensional gel electrophoretic analysis with immobilized pH gradients of Dactylis glomerata pollen allergens.

We studied Orchard grass pollen allergens (Dactylis glomerata) by a new two-dimensional electrophoretic technique which is the combination of isoelectric focusing (IEF) in immobilized pH gradient (IPG) and horizontal SDS-PAGE. The IPG-Dalt (two-dimensional gel electrophoresis with immobilized pH gradients in the first dimension) electrophoresis was made with four different but complementary pH gradients: 3-10.5, 4-9, 4-7, 6.3-10.5. We also compared the behavior of allergens in native and denaturing conditions during IEF. This technique followed by electroblotting on nitrocellulose membrane and immunodetection with an allergic patient serum was shown to increase the number of IgE-binding components up to 100 compared to one-dimensional techniques. Major allergen groups could be identified. New allergens not yet described could be characterized by their isoelectric points and their molecular masses. This highly resolving and reproducible technique, should allow an easy allergen standardization.

Allergens↗
PubMed1992

Modified silver staining for immobilized pH gradients.

Silver development of gels containing an immobilized pH gradient has proved difficult so far because the bonded buffers (especially the tertiary amino acrylamido derivatives) tend to absorb silver ions with a resultant heavy background of increasing darkness from the anode to the cathode. We report a variant of silver staining in which thiosulfate is used twice: (i) prior to silver impregnation, at the millimolar level, to enhance sensitivity, and (ii) during development, at the micromolar level, to decrease the background.

Hydrogen-Ion Concentration↗
PubMed1991

Cocksfoot grass pollen allergens and genetic of immune response.

The genetic basis of allergic response to grass pollen allergens of 23 portuguese families have been studied. The two or three generations families formed a total of 128 individuals including at least one parent and one child sensitive to Dactylis glomerata grass pollen. HLA class II genes were studied by PCR amplification and RFLP analysis. Our population study has revealed a higher frequency of allele 2 of DOB in the allergic population than in non allergic individuals. 60% of cocksfoot sensitive patients are DR4 as compared to 20% in healthy population. Using the immunoprinting technique to study the specificity of the different immunoglobulin isotypes, we were able to improve the phenotyping quality. This analysis showed that patient IgG4 and IgE recognize frequently the same allergens. Some pollen allergens phenotypes (IgE) are transmitted from parents to children. Pollen specific IgG1 or IgG3 phenotypes might be better markers than IgA or IgM phenotypes to follow the natural immune response transmission in family studies.

Allergens↗
PubMed1991

[Study of loosening and wear of total hip prosthesis. Apropos of a series followed-up over 10 years].

After reviewing 30 cases of patients having had a total hip arthroplasty by the Charnley's technique between 1970 and 1978, the authors study the radiographic parameters of the cup and of the femoral stem, using geometric buildings described by Sutherland. On the acetabulum, the inclinaition angle, the medialisation and the wear of the cup were calculated. The varisation of the stem and its migration were looked for on the femur. The presence of a radiolucent line, prosthesis--bone or cement--bone and the importance of peri-articular calcifications, was also noted. The verticalisation of the cup and its anteversion were a pejorative factor. The medialisation was disquieting only if it was associated with a verticalisation. The wear more than 2 mm was noted only in 5 cases; the radiolucent line was pejorative only if it was type cement--bone; the type cement--cup, rare, was of less bad prognostic. On the femur, the most failing was the varus of the stem which determined a loosening most often when it was present. The disquieting radiolucent line was always type cement--bone and was always associated with a bicortical reaction showing a mobility of the stem. In a last part, the authors studied the wear of expanted cups in polyethylene which was different of the fluage. A distinction between the theoretical wear and the clinical wear was made. Photographs in scanning electron microscopy which permit to describe the different types of wear are presented.

Adult↗
PubMed1990

Multiple successive immunoprinting: a fast blotting technique of a single agarose isoelectric focusing gel.

Multiple successive pressure blottings of a single agarose isoelectric focusing gel were performed on normal and CNBr-activated nitrocellulose (NC) filters. The results obtained by multiple successive 10s immunoprints were compared to those obtained by a single 10 min immunoprint. To quantify the transfer efficiency of these techniques, a defined amount of radioactive material was separated by isoelectric focusing on agarose gel. After separation and pressure blottings of the gel the NC filters were submitted to autoradiography. The amount of radioactive material bound to the NC filters was determined by scintillation technique. The single 10 min pressure blot was more efficient than each of the multiple successive 10s prints. However, the latter procedure allowed equal resolution and resulted in a higher recovery of total radioactivity than the single immunoprint technique. The aim of this paper is to show how to obtain highly reproducible prints of electrophoretic patterns in an agarose gel of heterogeneous samples when accurate multiple immunodetections are to be performed. This technique was tested to characterize the grass pollen specific immunoglobulin classes and subclasses from an allergic patient.

Humans↗
PubMed1989

Characterization of grass pollen-specific IgE, IgA, IgM classes and IgG subclasses in allergic patients.

Water-soluble grass pollen extracts (Dactylis glomerata) were separated by isoelectric focusing in a wide pH range (2-11) in agarose gel. After focusing, two successive gel prints were taken. The first one, on an ordinary nitrocellulose filter during 10 s, enabled the visualization of separated components of the pollen, after india ink staining. The second one, on a cyanogen bromide-activated nitrocellulose filter obtained after a 10-min transfer and saturation step, was incubated overnight with patient sera, and the specific antibodies bound to antigens or allergens were detected. The screening of different patient sera showed great variability in the antigen spectra. There was no obvious relationships between IgM and IgA antigen spectra as compared to IgE. Some association between IgE and IgG4 subclass was observed.

Allergens↗
PubMed1988

Study of the epitope structure of purified Dac G I and Lol p I, the major allergens of Dactylis glomerata and Lolium perenne pollens, using monoclonal antibodies.

The use of mAb allowed us to further analyze the cross-reactivity between purified Dac g I and Lol p I, the major allergens of Dactylis glomerata (cocksfoot) and Lolium perenne (Rye grass), respectively. It was first shown, using IEF, followed by immunoprinting, that serum IgE antibodies from most grass-sensitive patients recognize both Dac g I and Lol p I. Second, three different anti-Lol p I mAb, 290A-167, 348A-6, and 539A-6, and one anti-Dac g I mAb, P3B2 were all shown to react with Dac g I and Lol p I, indicating that the two molecules share common epitopes. Epitope specificity of the mAb was determined by competitive binding inhibition of a given labeled mAb to solid phase fixed Dac g I or Lol p I by the mAb. The results indicated that the four mAb are directed against four different and non-overlapping epitopes present on both allergens. Using double-binding RIA, our data strongly suggest that the common epitopes are not repetitive on both molecules. In addition to their similar physicochemical characteristics, such as isolectric points and m.w., Dac g I and Lol p I share four identical epitopes. Binding inhibition of human IgE to Lol p I and Dac g I by the mAb was also assessed. The results indicated that each mAb was able to inhibit such reactions to variable degree but no additive inhibition was observed when two mAb of different specificities were used in combination, suggesting that the human IgE binding site is partially shared by each epitope recognized by the four mAb.

Allergens↗
PubMed1987

Monoclonal anti-human IgE: histamine release capacity and effect on in vitro sensitization of human basophils.

IgE-anti-IgE complexes were formed by preincubation of a human myeloma IgE with a monoclonal anti-human IgE antibody at different concentrations. Binding of IgE onto the anti-IgE inhibited the histamine release capacity of anti-IgE from basophils. The IgE cell-binding capacity was altered by the IgE/anti-IgE ratio in the preincubation buffer. Heating of the complexes gave a partial recovery of the anti-IgE degranulation capacity, suggesting that the monoclonal anti-IgE is specific for an epitope present on the D epsilon 2 domain.

Antibodies, Anti-Idiotypic↗
PubMed1986

Thermoinactivation of human IgE: antigenic and functional modifications.

The thermoinactivation kinetics of IgE were studied in experimental models revealing the antigenic properties and the basophil-sensitizing capacity of these immunoglobulins. A pool of human sera containing anti-Dactylis glomerata (Dg) IgE was heated from 5 min up to 4 hr at 56 degrees. The IgE antigenicity was tested by two polyclonal 125I-labelled anti-IgE antibodies; one anti-IgE was specific of the whole Fc epsilon region, while the other had a specificity restricted to the D epsilon 2 domain. Radioimmunoassays showed that the D epsilon 2 epitopes were more rapidly altered than the D epsilon 1 epitopes. The capacity of IgE to bind to basophil Fc epsilon receptors was assayed by passive sensitization experiments. Basophil sensitivity towards the Dg pollen extract was tested by histamine release experiments in the presence of this allergen. A progressive decrease in cell sensitivity was observed when IgE samples used for cell sensitization were heated for longer than 5 min. Thermoinactivation kinetics of IgE revealed an unexpected increase in the apparent quantity and biological activity of IgE heated for 5 min at 56 degrees. This fact could be due to auto-anti-IgE antibodies linked to the unheated IgE and which interfere with the biological activities of IgE and their quantification.

Basophils↗
PubMed1986

[Desensitization for 4 successive years using calcium phosphate-adsorbed pollen extracts: study of sera with RAST and PRIST immunoimprints].

The clinical study for four years running of desensitization treatment to adsorbed pollen calcium phosphate, prepared "at request" by Institut Pasteur, shows that these preparations produced particularly good results. The population of allergic subjects is divided into two categories as from first year of treatment: good responders and non responders. A study on the serums of these patients, in view of a different "immuno-imprint" in these two groups, has not yet been conclusive, whereas we were expecting much from this prognosis test, which would have given us better treatment information.

Adolescent↗
PubMed1985

Purification and characterization of a major allergen from Dactylis glomerata pollen: the Ag Dg1.

We have isolated an allergen (Ag Dg1) from Dactylis glomerata pollen which is recognized by the serum of 95% of human patients sensitive to D. glomerata pollen, as has been shown by the nitrocellulose immunoprint technique. After two successive purifications by preparative isoelectric focusing (IEF), Dg1 was characterized as a single band in analytical agarose IEF with a pI of 5.9 and was found to display 3 bands by sodium dodecyl sulfate polyacrylamide gel with the respective molecular weights: 21,000, 31,000 and 33,000 daltons. The high recognition frequency by IgE antibodies of Dg1 in the sera of allergic patients and its ability to trigger histamine release from sensitized human basophils allow to consider that Ag Dg1 is the main major allergen extracted from D. glomerata pollen.

Allergens↗
PubMed1985

Induction of a passive cutaneous anaphylaxis inhibitory factor in mice.

The administration of a purified protein from Dactylis glomerata pollen, named Dactylis inhibitory protein (DIP), to Balb/C mice results in the production of a heat-resistant seric factor that blocks the passive cutaneous anaphylaxis (PCA) reaction in rat skin. This PCA inhibitory factor (PCA-IF) was purified following different purification procedures and analyzed in sodium dodecyl sulfate polyacrylamide gel. Amongst the array of bands detected it was possible to ascribe the inhibitory activity to a protein band of 76,000 daltons but only when it was associated either with another protein band of 69,000 daltons (obtained after a one-step purification procedure) or two other protein bands of 55,000 and 26,000 daltons (obtained after a three-step purification procedure). The inhibitory activity of the PCA-IF is present at a low level in normal Balb/C mice sera and is enhanced after DIP treatment of the mice.

Animals↗
PubMed1984

Rapid visual detection of Escherichia coli and Vibrio cholerae Heat-labile enterotoxins by nitrocellulose enzyme-linked immunosorbent assay.

A modification of the enzyme-linked immunosorbent assay for a sensitive and rapid visual detection of heat-labile enterotoxins from Escherichia coli and Vibrio cholerae is described. Small amounts of bacterial supernatant fluids are bound to nitrocellulose filters which are used as sorbents in the nitrocellulose enzyme-linked immunosorbent assay. The test is based on the immunological similarity between V. cholerae and E. coli heat-labile enterotoxins. Six isolates of V. cholerae and 48 isolates of E. coli were examined for heat-labile enterotoxins by the nitrocellulose enzyme-linked immunosorbent assay and the Vero cell bioassay. With some strains, the nitrocellulose enzyme-linked immunosorbent assay was found to be more sensitive for detection of E. coli heat-labile enterotoxin than the Vero cell test. A similar result was obtained by endpoint titration of heat-labile enterotoxin-positive E. coli H10407 culture fluid in both assays. The sensitivity of the nitrocellulose enzyme-linked immunosorbent assay for the detection of purified cholera toxin was at a total level of 1 ng, which is a good result when compared with other serological assays.

Animals↗
PubMed1984

[Treatment of primary vesicorenal reflux in adults. Apropos of 71 case reports].

The authors report a series of seventy one cases of vesico-renal reflux in adults. Renal scarring was present in 76% of the cases, and in 11.5%, the kidneys were destroyed. The reflux was eliminated in 95.5% of the cases treated by the Leadbetter-Politano, Cohen and Glenn Anderson procedures, but a failure rate of 26% was registered with the Lich Grégoir technique. 26.5% of the patients presented with persistent urinary tract infection six months after the successful surgical correction of the reflux.

Adolescent↗