[Fungal invasion of connective tissue in patients with gingival-periodontal disease]. / Invasión fúngica en tejido conectivo en pacientes con enfermedad gingivo-periodontal.

BACKGROUND: In the last few years unusual microorganisms have been isolated from subgingival biofilm, as possible initiators or contributors to periodontal disease, especially in patients who show no improvement during treatment. AIMS: To study the Candida invasion of the connective tissue in relation to subgingival biofilm presence. METHODS: A total of 55 immunocompetent patients of both sexes, between 21 and 55 years of age, non-smokers, without previous antimicrobial treatment, suffering periodontal diseases, were studied. Soft tissues, supragingival and subgingival plaque samples, and periodontal pocket biopsies were taken. Microscopic studies, cultures, assimilation profiles, and DNA amplifications were performed. RESULTS: In 35% of the samples, different species of Candida were isolated in cultures, especially Candida albicans. Hyphae invasions in the connective tissue were observed, in association with anaerobic microorganisms (Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans) in patients with periodontitis. CONCLUSIONS: Different species of Candida could be part of the periodontal plaque and could play an important role in the adherence to soft tissues, allowing deep invasion. They also could infect gingival pockets in patients with gingivitis, even in healthy locations, playing a commensal or opportunist role.

Morphometrical quantification of Chlamydia pneumoniae and Mycoplasma pneumoniae in human atherosclerotic abdominal aortic aneurysms.

OBJECTIVE: Atherosclerotic inflammation with a possible role of infectious agents can contribute to the pathogenesis of abdominal aortic aneurysms (AAA). The finding of Chlamydia pneumoniae (CP) in these lesions in previous non-quantifying studies ranged from 0-100%. The objective is to quantify the presence of CP and Mycoplasma pneumoniae (MP) in AAA. METHODS: The thickness, and the number of cells positive for CP detected by the immunohistochemistry (immunoperoxidase, which is a type of immunohistochemical stain used in molecular biology, medical research, and clinical diagnostics), and the percentage of the area occupied by the Mycoplasma pneumoniae detected by in situ hybridization in three layers of the aorta were measured using an image-analysis system in 10 necropsies of abdominal aneurysmatic aortas. Three groups were used as controls: 1) samples of the same aortas, outside the aneurysms, except if the dilatation took the whole sub-renal portion of the artery (n=7); 2) aortas with severe atherosclerosis but without aneurysms (n=10); 3) aortas without or with mild atherosclerosis (n=10). All specimens were obtained at necropsies. Wald's test was used to compare groups; significance level was established at 5%. RESULTS: The tunica intima was thinner and the tunica media was thicker in the normal cases than in the other groups (p<0.01). Positive cells for CP were found in all groups, more frequently at the adventitia; no significant difference was detected between the groups (p>0.05). MP was also detected in all groups. This agent predominated in the group of patients with atherosclerosis, but without aneurysms at both tunica intima and adventitia; nevertheless, there were no significant differences between the groups (p>0.05). CONCLUSIONS: Our data suggested that the bacteria we focused to, does not play an important role in the pathogenesis of AAA.

Comparison of Fonsecaea pedrosoi sclerotic cells obtained in vivo and in vitro: ultrastructure and antigenicity.

The parasitic form of Fonsecaea pedrosoi from the hyperkeratotic layer of the skin was obtained from four patients with chromoblastomycosis. Primary cultures containing hyphae and conidia were successfully converted into sclerotic cells in the presence of 800 microM propranolol and low pH as described before. The morphology of sclerotic cells of F. pedrosoi obtained in vivo and in vitro was analyzed by light and electron microscopy. Their antigenicity was also compared by immunofluorescence microscopy and ELISA assays, using serum samples from untreated patients infected with F. pedrosoi. Due to the similarity of the sclerotic cells obtained in vivo and in vitro, the latter can be more adequately in studies of host-parasite interactions in chromoblastomycosis.

Decontaminating beef for Escherichia coli O157:H7.

Beef lean, fat, and connective tissues were inoculated with Escherichia coli O157:H7 before and after a prewashing procedure to compare the efficacy of prewashing and no prewashing on bacterial adherence and, consequently, on the removal of bacteria from the inoculated surfaces. Prewashing consisted of spraying tissues with tap water before inoculation. Final washing with disinfectant solutions compared the efficacy of several chemicals for the removal or destruction of E. coli O157:H7. The results showed that prewashing was very effective in reducing the numbers of bacterial cells on beef tissues, mainly lean tissue, in the control samples which received final washing with water. An opposite effect of prewashing was observed when disinfectant solutions were used for final washing; this may be due to dilution by water carried on the tissues after prewashing. The efficacy of chemicals was dependent on the type of exposed tissue. Hydrogen peroxide (3%) was more efficient in the removal of E. coli O157:H7 from connective tissues, with reductions greater than 4 log CFU/cm2, compared to a normally washed control (P < 0.01). Chlorhexidine (0.1%) was very efficient on fat and lean tissues, causing reductions over 5 log CFU/cm2 on not prewashed fat and lean tissues, compared to the control (P < 0.01). Acetic acid (5%) was the least effective, decreasing the number of CFU by under 1 log/cm2 as compared to the control; and no statistically significant difference was found among tissues, even though the removal of bacteria seemed less in lean tissue compared to fat or connective tissues.

Field emission scanning electron microscopy study of the mouse lingual mucosa, with special reference to adhesion of bacteria in the epithelial cell membranes

The dorsal surface of three-day postnatal mouse tongue was examined by field emission scanning electron microscope and revealed that the fungiform papillae are round in shape and filiform papillae present small projection in development. The surface of interface of epithelium-connective tissue showed small projections of papilla corresponding to the filiform and fungiform papillae. The surfaces of epithelial cell membranes present numerous microplicae with adhesion of streptococcus. These bacteria are attached on the cell membrane in organized rows of rat random, demonstrating their three-dimensional FESEM images. At high magnification, on ther surface of each bacteria may be noted small particles.

Implantes y periodoncia / Dental implants and periodontics

Se evaluará la estrecha relación entre implantes y tejidos periimplantarios. Se indicará cómo prevenir patología en esa área o bien cómo tratarlas cuando se han producido

Implantes y periodoncia / Dental implants and periodontics

Se evaluará la estrecha relación entre implantes y tejidos periimplantarios. Se indicará cómo prevenir patología en esa área o bien cómo tratarlas cuando se han producido (AU)