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C Mouton

Publications and source records attributed to C Mouton.

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

The lipopolysaccharide of Porphyromonas gingivalis is not antigenically cross-reactive with that of other species.

Large numbers of Porphyromonas, Prevotella, and Bacteroides strains were screened by 3 monoclonal antibodies (MAbs) and 8 rabbit antisera raised against Porphyromonas gingivalis, in order to detect any possible recognition of non-P. gingivalis surface antigens by these immunoreagents. All three MAbs, which were LPS-specific, extensively recognized LPS from 10 P. gingivalis strains in immunoblotting, whereas they recognized none of the 34 non-P. gingivalis strains. Rabbit antisera were similarly specific for P. gingivalis cells in immunofluorescence and with LPS in grid-blotting, but several of them recognized LPS from one Prevotella melaninogenica and 5 Prevotella intermedia strains in Western blotting. Since several pre-immune sera and an irrelevant serum raised to a Streptococcus species recognized up to 5 of these preparations, we exclude that the reactions were due to antigens shared by P. gingivalis and Prevotella. Rather, we consider that they were false-positive reactions due to natural antibodies, stimulated in a non-specific manner upon immunization with P. gingivalis, in animals whose immune systems were sensitized to Prevotella species before immunization.

Antibodies, Bacterial↗
PubMed1993

A rapid method for preparation of rough and smooth lipopolysaccharide from Bacteroides, Porphyromonas and Prevotella.

We describe a new method for lipopolysaccharide (LPS) preparation by water extraction at 100 degrees C and subsequent digestion with proteinase K. The crude LPS could be reliably used for immunoblotting since it retained a high level of antigenicity, and was free of SDS and proteinase K, both of which can cause problems. Two monoclonal antibodies which failed to react with LPS prepared by two conventional methods reacted well with our preparation. We used the new method to prepare LPS from 44 strains of bacteria formerly classified as Bacteroides, some of which have been reclassified as Porphyromonas or Prevotella. In general, yields were good, and electrophoretic profiles obtained with SDS-PAGE and silver staining enabled strains to be rated rough, semi-rough, or smooth.

Animals↗
PubMed1993

Prospective study of risk factors in natural rubber latex hypersensitivity.

Five hundred sixty-nine subjects routinely underwent skin prick tests for latent sensitization to latex. The study of risk factors included skin tests to inhalant allergens, to diagnose atopy, and a questionnaire aimed at revealing frequent exposure to latex such as the wearing of gloves, multiple surgical procedures, or urinary catheterization. The subjects were categorized into five groups: group I, subjects with no risk factor (n = 272); group II, nonatopic subjects exposed to latex (n = 73); group III, atopic subjects not exposed (n = 180); group IV, exposed atopic subjects (n = 44); and group V, subjects with a history of intraoperative anaphylactic shock caused by latex (n = 13). Twenty-five subjects had spina bifida and were in either group II (14 subjects) or group IV (11 subjects). The questionnaire identified a probable allergy to latex in 18 subjects: 16 cases were confirmed by skin test, but responses were not informative in 23 patients who were sensitive to latex. Positive prick tests to latex were obtained in 0.37% of group I, 6.85% of group II, 9.44% of group III, and 36.36% of group IV. Of the children with spina bifida, 32% had positive skin test results. As risk factors, atopy and exposure were synergistic. We recommend predictive prick tests not only in children with spina bifida but also in any atopic subject or in any patient with a history of frequent exposure to latex. Latex could be considered a habitual allergen. The use of latex urinary catheters should be avoided in patients who are catheterized on a daily basis.

Adolescent↗
PubMed1993

Comparison of three molecular typing methods in studies of transmission of Porphyromonas gingivalis.

Porphyromonas gingivalis is associated strongly with severe periodontitis, but little information is available on possible transmission routes of this species. This study evaluated three DNA-based molecular typing methods for use in epidemiological surveys of P. gingivalis. In total, 32 isolates from eight married couples were investigated by: (i) restriction endonuclease analysis (REA) of whole chromosomal DNA; (ii) hybridisation of DNA fragments with ribosomal DNA (ribotyping); and (iii) amplification of DNA by the polymerase chain reaction with arbitrary primers (AP-PCR). The data obtained with the three methods were in broad agreement: in six of the eight couples, the isolates from husband and wife were indistinguishable, but isolates from unrelated individuals showed distinct types with all three methods. For some isolates, minor differences in REA pattern were obtained which could not be correlated with differences in ribotype or AP-PCR type. Ribotyping showed differences between isolates from one individual, which were indistinguishable with the other two methods. The patterns obtained with ribotyping or AP-PCR were simple in comparison to the relatively complex REA patterns. Although all three methods were concordant, AP-PCR was found to be the least time-consuming method. The data support the suggestion that P. gingivalis can be transmitted between spouses.

Adult↗
PubMed1992

Application of polymerase chain reaction with arbitrary primer (AP-PCR) to strain identification of Porphyromonas (Bacteroides) gingivalis.

Several molecular methods are currently available for identification and discrimination of bacterial strains within the same species, which vary in efficiency and required labour. Here we applied a novel method for fingerprinting genomes, called arbitrarily primed PCR (AP-PCR), to the delineation of strains within the species Porphyromonas gingivalis. Using a single primer on a set of nine strains, nine simple distinct banding patterns, indicative of genetic polymorphism, were observed. Common amplicons and amplicons shared by only some strains were also observed, the latter suggesting that AP-PCR can be used to generate polymorphic markers. Genomic fingerprinting obtained by AP-PCR was independent of the quality of DNA. Assays performed directly using whole cells as a source of DNA template indicated that AP-PCR from colony is a quick, simple and accurate procedure.

Base Sequence↗
PubMed1992

Epitope mapping of hemagglutinating adhesion HA-Ag2 of Bacteroides (Porphyromonas) gingivalis.

Thirteen monoclonal antibodies (MAbs) directed against hemagglutinating adhesion HA-Ag2 of Bacteroides (Porphyromonas) gingivalis were produced by immunizing mice with the relevant immunoprecipitate from crossed immunoelectrophoresis (CIE). Crossed immuno-affinoelectrophoresis and hemagglutination experiments confirmed that our MAbs recognized a molecule able to bind erythrocytes and involved in the hemagglutination process. In immunoelectron microscopy, these MAbs labelled amorphous material as novel cell-bound appendages distinct from fimbriae. CIE experiments allowed differentiation of the MAbs according to reactivity with immunoprecipitates Ag2, Ag8a, and Ag8c, which define HA-Ag2. The epitopes recognized by nine MAbs were mapped on three main antigenic domains (I, II, and III) by competition experiments and further grouped according to chemical composition and distribution on CIE immunoprecipitate. Domain I, defined by two MAbs, comprises an epitope with protein and carbohydrate determinants and distributed on Ag2 only. Epitopes of domain IIA, defined by four MAbs, are distributed on Ag8a, Ag8c, and Ag2 and are essentially composed of protein determinants but also have carbohydrate determinants that enhance the binding of the MAbs but are not essential. Epitopes of domain IIB, defined by two MAbs, and of domain III, defined by a single MAb, have a composition similar to that of domain IIA epitopes but are distributed on Ag8a and Ag8c only. A competition enzyme-linked immunosorbent assay with serum from normal subjects and patients with periodontitis suggested that domain I is more immunogenic than domain II.

Adhesins, Bacterial↗
PubMed1992

Food contains the bioactive peptide, cyclo(His-Pro).

Cyclo(His-Pro) (CHP) is a cyclic dipeptide with numerous biological activities. As small di- and tripeptides may be absorbed intact when ingested orally, we were interested in examining several common foods for the presence of cyclo(His-Pro)-like immunoreactivity (CHP-LI). In all foods tested, CHP-LI was found at levels 5-1500 times those previously found in human plasma. This CHP-LI was identical to authentic CHP by immunoidentity and chromatographic behavior. We conclude that 1) CHP-LI is readily detectable in several common food sources; 2) this CHP-LI is indistinguishable from authentic CHP; and 3) it is likely the CHP-LI in foods is absorbed in quantities sufficient to cause elevations of CHP-LI in plasma to biologically significant levels.

Chromatography↗
PubMed1992

A multivariate model to predict caries increment in Montreal children aged 5 years.

A study was carried out in Montreal (Canada) to predict caries development over the period of one year in primary teeth of kindergarten children (mean age 5 years 8 months +/- 4 months) living in a non-fluoridated area. The 302 children were examined at school on two occasions, one year apart. At the first examination selected predictors were collected: caries experience, salivary S. mutans and lactobacilli, buffer capacity, debris index, parents' education, fluoride consumption and family structure (one or two parents). Regression analysis was performed to select the significant factors. A total of 143 children developed new caries over the study period; the mean increment for the whole group was 2.1 dmfs. Sensitivity (Sn) and specificity (Sp) were calculated for each predictor and for the final model. The best model comprised only two factors, caries experience and lactobacillus. This could identify 81.8 per cent of children who would develop new caries during the next 12 months (Sn) and 77.4 per cent of those who would not (Sp). Among the single predictors caries experience alone reached 78.3 per cent for sensitivity and 77.4 per cent for specificity. None of the other predictors, except parents' education, was very good at predicting caries increment over one year.

Chi-Square Distribution↗
PubMed1991

The hemagglutinating adhesin HA-Ag2 of Bacteroides gingivalis is distinct from fimbrilin.

We carried out a series of immunoblots with antigenic preparations from the periodontal pathogen Bacteroides gingivalis using antisera of restricted specificity for the hemagglutinating adhesin HA-Ag2, and for the major structural subunit of the fimbriae (fimbrilin). We have been able to show that these 2 antigens are distinct. The fimbrilin subunit had an apparent molecular weight of 42 kDa in all of the bacterial preparations tested. HA-Ag2 occurred as a pair of bands at 43 and 49 kDa in outer membranes prepared as extracellular vesicles, and at 33 and 38 kDa in glass-bead-EDTA extracted antigens and in sheared-cell outer membranes prepared in the presence of EDTA. No HA-Ag2 was found in an enriched fimbrial preparation. The 2 antigens could thus be distinguished on the basis of their behaviour when subjected to different extraction techniques. The lower apparent molecular weight of HA-Ag2 (a pair of bands at 33 and 38 kDa) was invariably associated with the presence of EDTA in the buffers used to prepare the extracts, and the effect could be partially prevented by adding MgCl2 to the extraction buffer. The difference in apparent molecular weight of HA-Ag2 in the different extracts can thus be attributed either to an EDTA-sensitive tertiary conformation of its component polypeptides, or to an EDTA-sensitive linkage of each of these polypeptides to an unknown component of approximately 10 kDa.

Adhesins, Bacterial↗
PubMed1991

Targetting the production of monoclonal antibodies to the hemagglutinating adhesin of Bacteroides (Porphyromonas) gingivalis by injection of an immunoprecipitate from crossed immunoelectrophoresis.

This study has demonstrated that the production of monoclonal antibodies (MAbs) can be targetted to a predetermined antigen by immunization with the relevant immunoprecipitate (IP) excised from an agarose gel. The target antigen was the hemagglutinating adhesin HA-Ag2 of Bacteroides (Porphyromonas) gingivalis precipitated from a crude antigen extract with a rabbit antiserum in crossed immunoelectrophoresis. The immunization protocol used included: subcutaneous injection of 1 IP in Freund's complete adjuvant to Balb/c mice on day 0 and of 0.5 IP on day 8, followed by an intravenous booster injection of outer membranes on day 15, 4 days before the fusion. Of the 9 MAbs obtained, 8 were specific for HA-Ag2 since they reacted with its characteristic electrophoretic bands at 43 and 49 kDa. The ninth MAb was specific for the B. gingivalis lipopolysaccharide. The method allows for easy obtention of MAbs of predetermined specificity without purification of the antigen.

Animals↗
PubMed1991

[Bacterial periodontal plaque in childhood. Literature review].

Bacterial colonization is investigated: before eruption, in primary dentition, mixed dentition and permanent dentition, with and without gingival inflammation. Microorganisms such as spirochetes and Black pigmented Bacteroides are implicated in the periodontal disease. These germs arrive later than teeth and their importance grows with age and gingival inflammation. Different reviews have emphasised the potential role of specific pathogens in the aetiology of periodontitis. The plaque composition of necrotizing ulcerative gingivitis and periodontitis in their pre and post pubertal forms, localized and generalized is investigated. A actinomycetemcomitans, B. intermedius and spirochetes can be isolated from children having destructive periodontal disease. Changes in flora can then be explained.

Adolescent↗
PubMed1990

Assay of serum cardiac myosin heavy chain fragments in patients with acute myocardial infarction: determination of infarct size and long-term follow-up.

To evaluate the correlation between myosin heavy chain release and the necrosis mass, serum levels of myosin heavy chain fragments were determined serially in 55 patients with acute myocardial infarction. Eight of these patients were successfully treated with thrombolytic agents: the others were not treated. The same myosin titration was applied to the sera of 25 dogs with an experimental myocardial infarction. Six of the dogs were successfully treated with thrombolytic agents. The time courses of the myosin concentrations are typical and monophasic for all patients with a noncomplex myocardial infarction. The values for the kinetic parameters of myosin release are comparable to those previously reported. We have now determined that cumulative myosin release significantly correlates with cumulative creatine kinase (CK), CK-MB, and lactate dehydrogenase release, as well as with thallium-201 distribution, as determined for different patient groups. Thrombolytic treatment does not seem to qualitatively upset myosin kinetics. The results obtained in dogs with or without thrombolysis conclusively indicate that myosin release is a quantitative index of the necrosis mass. From a practical point of view, a few serial determinations of serum levels of myosin heavy chains are enough to estimate the necrosed mass in patients with acute myocardial infarction. More generally, serum myosin titration could be useful in detecting any cardiac disturbance involving myocardial injury resulting in membrane leakage of cardiac cells.

Adult↗
PubMed1990

[Anesthetics responsible for anaphylactic shock. A French multicenter study].

Combined allergological and anaesthetic consultations have been started in the last few years in eight French Teaching Hospitals so as to explore peranaesthetic anaphylactoid shocks. A survey was carried out in these centers in order to collect patients investigated with the same protocol, for the assessment of the incidence of anaphylaxis in France, as well as the involved drugs. Investigations were always carried out at least 6 to 8 weeks after the accident. The tests used to diagnose IgE-dependent anaphylaxis were skin tests (prick and intradermal tests, carried out in all eight centers), the radioimmunological assay of specific anti-quaternary ammonium IgE, together with an inhibition test with thiopentone and propofol (six centers), leukocyte histamine release (five centers) and human basophil degranulation tests (three centers) for those drugs for which no specific antibody assay exists. The collected data involved 1,240 patients, investigated within the last four years. Anaphylaxis was diagnosed in 821 patients (66.2%). Muscle relaxants were responsible in 668 cases (80% of cases of anaphylaxis). Suxamethonium was the main cause (54.3% of shocks due to muscle relaxants), followed by vecuronium (15.3%). General anaesthetics (hypnotics and benzodiazepines) were responsible for 9.2% of all cases of anaphylaxis opioids for 2.6%. There were only three cases of shock due to local anaesthetic agents. Latex and ethylene oxide are becoming increasingly involved. It would therefore seem mandatory to carry out after any anaphylactoid accident an assessment with sensitive and specific tests for anaphylaxis. Diagnosing anaphylaxis means that the involved drug should be used never again in that patient. Because muscle relaxants are by far the most involved drugs, anaesthetists should use them only when really required.

Analgesics, Opioid↗
PubMed1990

Simultaneous anaphylaxis to thiopentone and a neuromuscular blocker: a study of two cases.

Two women experienced anaphylactoid reactions after induction of general anaesthesia. Prick tests, intradermal tests (IDT), human basophil degranulation tests (HBDT) and a quaternary ammonium sepharose radioimmunoassay were undertaken several weeks later and repeated together with a leucocyte histamine release (LHR) test after 4 months. Anaphylaxis to suxamethonium was documented by four tests in patient 1 and to pancuronium by four tests in patient 2. Anaphylaxis to thiopentone was shown with IDT, HBDT and LHR in both women. It was concluded that simultaneous anaphylaxis to thiopentone and a neuromuscular blocker had occurred in these patients.

Adult↗
PubMed1990

SDS-PAGE analysis of protein and lipopolysaccharide of extracellular vesicules and Sarkosyl-insoluble membranes from Bacteroides gingivalis.

We have compared outer membranes (OM) of Bacteroides gingivalis ATCC 33277 isolated by the following 3 techniques: 1) high speed centrifugation after mechanical cell shearing; 2) sonication of the bacteria, followed by solubilization of the cytoplasmic membrane with N-Laurylsarconsinate (Sarkosyl), after which the Sarkosyl-insoluble membranes were recovered by centrifugation; 3) ammonium sulfate precipitation of extracellular vesicules from culture supernatant, followed by centrifugation and dialysis. Electron microscopy showed that the 3 preparations consisted of closed vesicules. Analysis by SDS-PAGE revealed that all 3 contained up to 28 polypeptides, most of which were common to each extract. The extracellular vesicules and Sarkosyl-insoluble preparation yielded similar protein patterns, although quantitative differences were observed. The sheared-cell preparation contained 8 additional proteins. The level of contamination of OM material by peptidoglycan and cytosol components was 1.8% in the sheared-cell preparation, and was null or lower than 0.8% in the other preparations. All 3 preparations showed the presence of LPS with a multiple banding pattern typical of smooth LPS. The sheared-cell preparation had a slightly lower LPS content than the other 2 preparations. Since extracellular vesicules are naturally released during bacterial growth, and are relatively simple to obtain, such native entities seem an appropriate source of OM components for use in studying the immunobiology of B. gingivalis surface antigens.

Bacterial Outer Membrane Proteins↗