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Biomedical subjects

J P Lodter

Publications and source records attributed to J P Lodter.

At least 19 recordsLinked to original sources

Metronidazole susceptibility testing of anaerobic bacteria associated with periodontal disease.

The aim of the present investigation was to determine the susceptibility of Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium and Peptostreptococcus micros to metronidazole in vitro. Two methods were applied on each isolated strain: agar dilution and epsilometer Etest. A total of fifty three wild test strains (13 P.intermedia, 14 P. gingivalis, 14 F.spp and 12 P.micros) were isolated from patients with periodontitis. The Etest appears to be a simple, rapid and reliable method for the metronidazole susceptibility testing. The results show that all P.intermedia, P.gingivalis and F.spp strains were susceptible to metronidazole. The mean values of minimal inhibitory concentration obtained with the agar dilution method were, respectively, 0.98 microg/ml, 0.122 microg/ml and 0.242 microg/ml. For P.micros, the minimal inhibitory concentration was of 12.14 microg/ml. Comparatively to break points, only 60% of P.micros strains seem to be susceptible, in vitro, to metronidazole. This study demonstrated the excellent activity of metronidazole against P.intermedia, P.gingivalis, F.spp except perhaps for P.micros.

Anti-Bacterial Agents↗

Salivary defence factor concentrations in relation to oral and general parameters in HIV positive patients.

The objective of this study was to determine the relationships between saliva protein concentrations, oral mucosal lesions, and systemic parameters in HIV positive patients and controls. Twenty-three control volunteers and 58 HIV-antibody positive patients received a complete oral examination and medical evaluation. In saliva and serum samples, protein concentrations were recorded by a nephelometric method. The systemic parameters assessed were CD4+ cell count, CDC stages and antiretroviral therapy. Oral mucosal lesion prevalence was higher among subjects with lower CD4+ counts. Considering the protein profile, correlations were recorded between saliva and serum protein concentration for IgA, haptoglobin and alpha1-proteinase inhibitor. Using assays of immune and non-immune saliva defence factors, we found that the evolution of cellular immuno-suppression during HIV infection was correlated to oral mucosal disease, showing a relationship between local and general systems.

Adult↗

In vitro study of the penetration of three bacterial strains into root dentine.

The purpose of this study was to assess in vitro migration of the following three bacterial species into dentinal tubules: Streptococcus sanguis, Actinomyces naeslundii and Prevotella intermedia. Twenty-seven bovine incisors were randomly divided into three groups. Only the root dentin was used for the experiment. Within each group, the nine incisors were sectioned into 36 dentin blocks that were incubated with one of the tested bacterial suspensions. Twelve samples were taken after 10, 20, and 28 days. Half the samples were observed with scanning electron microscopy and the others with light microscopy after standard histologic procedures, and the depth of bacterial penetration was measured. Analysis of the examinations showed that whatever the technique used, only one strain on this experimental model migrated into dentinal tubules. S. sanguis was observed at a depth of 792 microns, but no migration was observed for either A.naeslundii or P.intermedia. The differences in migration of the bacteria tested appear to be related to their morphologic factors and cellular arrangement.

Actinomyces↗

[The adhesion of Actinobacillus actinomycetemcomitans to oral epithelial cells].

Adherence is a major pathogenicity factor for many bacteria. The aim of this study was to measure the adherence potential of Actinobacillus actinomycetemcomitans (A.a.) for buccal epithelial cells (BEC). In the second part of the study, the inhibitory potential of saliva on adherence between A.a. and BEC was tested. Saliva specimens were obtained from three groups of subjects: a group of normal subjects (NS), a group of subject with localized juvenile periodontitis (LJPS) and a group of subjects with adult periodontitis (APS). Clinical strains of A.a. showed a major adherence potential for BEC (25.5 A.a./BEC). In contrast, reference strains of bacteria appeared to possess a much lower potential for adherence (12.6 A.a./BEC). Saliva samples taken from from the LJPS and APS group had a high inhibitory adherence potential, since in each of these groups a reduction of 60.9% and 66.7% respectively, was observed in the number of bacteria adhering to BEC.

Adolescent↗

[Mastication and the electromyographic silent period in denture wearers].

The purpose of this study is to compare the masticatory efficiency and the physiological activity of masticatory muscles among patients with removable partial dentures (R.P.D.) and patients with natural dentition. The masticatory efficiency is assessed from the duration of chewing sequences for various foods, from the first masticatory cycle to the swallowing. The physiological activity is tested by the duration of the inhibition reflex called the "silent period" (S.P.) obtained upon each muscle examined: 29 subjects are examined, 24 of them had a R.P.D.; they were divided into four groups according to the extent of their edentation; 5 control subjects have full natural dentition. The study is performed using global electromyography of the two masseter muscles and the two anterior temporal muscles. The mastication of the control subjects appears to have a regular alternance of working potential and periods of rest. The duration of the chewing sequences is determined by the nature of the food, brief for soft food, long for hard food. The mastication of patients with R.P.D. appears more irregular with a lengthening of active phases. The duration of chewing sequences is significantly longer for the control subjects. The duration of the S.P. is 19-21 milliseconds for the masseter muscles of the patients with dentures and the control patients, and 20-22 milliseconds for the temporal muscles for the same individuals. The differences of the S.P. durations between control subjects and patients with R.P.D. is never significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[A comparison between 4 subgingival bacteriologic sampling technics].

A comparative study of four classical techniques employed in the sampling of subgingival microflora (paper points, swabbing, curette and washing followed by aspiration) has been carried out. This study was based upon quantitative criteria (number of bacteria sampled) and qualitative criteria (number of morphologically distinct colonies found per sampling technique). Sampling was done on three different groups of patients: a control group, a group of patients with gingivitis and a group of patients with periodontitis. The curette sampling technique was found to be efficient both quantitatively and qualitatively. Difficulties in standardizing this method however were encountered with the failure to achieve reproducible results. For this reason the technique of paper point was preferred. This method was found to be more reliable and reproducible in each of the three groups of patients sampled.

Adult↗

[The transmission of Actinobacillus actinomycetemcomitans between spouses].

The aim of this investigation was to study the transmission of Actinobacillus actinomycetemcomitans (A.a) between husband and wife when one of them was affected by acute juvenile periodontitis (P.A.J.). The hypothesis tested was the role played by the reservoir of the non-infected partner in explaining the frequent recurrences of the disease in the affected spouse despite combined antibiotherapeutical and surgical treatments. Twenty subjects with P.A.J. were studied. A.a. was found in the sub-gingival flora of nineteen of them. This micro-organism was also isolated in each of the partners of the nineteen patients. Each couple presented strains of the same biotype. The serotypes were studied in seven of these couples and confirmed the results of the biotypes. All theses results are in favour of the transmission of A.a. between partners.

Actinobacillus↗

[The distribution and prevalence of Haemophilus actinomycetemcomitans in the oral cavity].

The prevalence and distribution of Haemophilus actinomycetemcomitans (H.a.) were studied in 3292 specimens of subgingival plaque on the four subgingival aspects of all teeth of the dental arch, 150 specimens from the mucosal surface (tongue and cheek) and 30 saliva specimens in 30 subjects. The sample population of 30 subjects was subdivided into three groups: 10 normal subjects, 10 subjects with localised juvenile periodontitis (SLJP) and 10 subjects with adult chronic periodontitis (SACP). The prevalences of H.a. in subgingival areas of each group mentioned were 30%, 90% and 60% respectively. Scores for prevalence obtained with other types of specimens proved to be lower except for saliva specimens which appear to be a less representative marker of subgingival prevalence of H.a.. Histograms for the distribution of H.a. revealed a predominance of this microorganism on the proximal surface of molar teeth in the three groups of patients. Only the SLJP also exhibited a high prevalence on the proximal aspect of the incisor teeth. The wide distribution of H.a. in all of the clinical groups studied suggests that this bacterium is not a good marker of periodontal disease and that it is necessary to define the most characteristic phenotypes and genotypes.

Actinobacillus Infections↗

Presentation and physical evaluation of RadioVisioGraphy.

A comparison of physical properties has been made between conventional intraoral films and images made with the RadioVisioGraphy (RVG) system, a unit based on the charged coupled device. The RVG system uses considerably reduced levels of radiation to produce an image immediately after exposure. RVG resolution is slightly lower than that with silver halide emulsion films; however, radiographic information may be increased by electronic image treatment.

Densitometry↗

The silent period duration of the masticatory muscles.

This study was conducted to determine whether the reflex activity of the masticatory muscles is altered in prostheses wearers. The electromyographic silent period was measured on an oscilloscope screen. Thirty subjects were examined. Five subjects had natural dentitions. Twenty-five partially edentulous subjects wore removable prostheses. The silent period duration reached 18 to 21 ms on the masseter muscles and 20 to 22 ms on the temporal muscles. These values were not significantly different for subjects with and without teeth and in the control group. The duration of the silent period was the same for patients wearing prostheses and for subjects with natural teeth. This finding suggests that wearing a prosthesis does not change the normal activity of the masticatory muscles.

Denture, Partial↗

[Comparison of protein concentrations in saliva and serum].

Saliva and serum protein profiles composed of 12 proteins: IgA, IgG, IgM, albumin, transferrin, alpha 1-glycoprotein acid, alpha 2-macroglobulin, alpha 1-proteinase inhibitor, haptoglobine, C3C, C4 and CRP were obtained by laser nephelometry of aliquots of samples of non-stimulated whole saliva and blood taken at the same time. The population of 138 controls of both sexes was divided into 4 age groups: 1 (20 to 29 years), 2 (30 to 39 years), 3 (40 to 49 years), 4 (50 to 60 years). Using the techniques developed for saliva assay, 10 proteins were measurable: IgA, IgG, IgM, albumin, transferrin, alpha 1-glycoprotein acid, alpha 2-macroglobulin, alpha 1-proteinase inhibitor, haptoglobulin and C3C. The C4 fraction and CRP were present at concentrations lower than the detection limit i.e. at 1.8 and 2.05 mg/l. In the serum 11 proteins were analysed, CRP occurring at less than 0.01 g/l. The statistical two-factor variance analysis test (sex and age) demonstrated the statistically significant influence of age in the saliva for alpha 1-PI and alpha 2-M in the serum for Tf, alpha 2-M and alpha 1-PI, and sex in the serum for IgG, IgM, alpha 1-PI, alpha 2-M and also the interaction of both factors in the serum for alpha 2-M.

Adult↗

[Electromyographic study of mastication as a function of the denture in humans].

A study of mastication was conducted using global electromyography of the masseter and anterior temporal muscles. Thirty subjects were studied and distributed between two groups. A control group of 5 patients had a complete natural dentition. A group of 25 patients presented important bimaxillary tooth-loss and wore dentures. They performed masticatory cycles with and without their dentures. The masticatory efficiency of the edentulous patients was very low when compared to the control group. The use of the dentures moderately improved function. The durations of activity of the temporal muscles were slightly lengthened (but not significantly) in the edentulous patients and the denture wearers compared to control patients. The cyclic pattern of the mastication tracings persisted. On the contrary, the durations of activity of the masseters muscles were strikingly lengthened until total disappearance of the resting phases. The cyclic pattern of the mastication tracings in controls disappeared in edentulous patients and denture wearers. In the latter, the tracings were less irregular than in the edentulous patients. In conclusion, the electrical activity of temporal muscles were slightly affected by the absence and replacement of teeth, whereas the electrical activity of the masseter muscles was markedly altered.

Adult↗