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Biomedical subjects

A Barone

Publications and source records attributed to A Barone.

105 records · Page 6Linked to original sources
PubMedDate not supplied

Tetracycline fibres used to control bacterial infection during guided tissue regeneration (GTR).

AIMS: The colonization of suspected periodontal pathogens during the healing of periodontal defects treated by guided tissue regeneration (GTR) with e-PTFE membranes and tetracycline fibers was investigated. METHODS: Fifteen patients, each with one pair of angular periodontal bone defects of comparable size and morphology were recruited for the study. In a matched-pair study design, the test defects were treated with e-PTFE membranes in combination with tetracycline fibers, while control defects were treated with e-PTFE membranes alone. Microbiological specimens were taken from control as well as from test sites preoperatively (T0), intraoperatively (T1), two weeks after surgery (T2) and from membranes at time of removal (T3). Cultural methods were used to identify the following species: Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn) and Actinobacillus actinomicetemcomitans (Aa). RESULTS: At baseline and T1, none of the suspected periodontal pathogens were detected at test or control sites. Levels of P. intermedia and F. nucleatum, as mean percentages of total culturable microflora, were detected at levels significantly higher in control sites than test sites at times T2 and T3. CONCLUSIONS: Findings from this study suggest that e-PTFE membranes are frequently colonized by periodontal pathogens, and that bacterial colonization of healing sites after GTR procedures can be kept under control with a controlled delivery system releasing tetracycline.

Aggregatibacter actinomycetemcomitans↗
PubMedDate not supplied

Caries-risk assessment: the role of salivary tests.

Although the incidence of caries has diminished dramatically over the past 3 decades, small groups of subjects remain highly susceptible and do not respond to conventional preventive programs. An accurate individual caries-risk assessment allows to identify the etiological factors responsible for the disease and design a rational approach to treatment, addressed to the specific needs of the patients. The use of appropriate caries-risk prediction models, which include the use of simple chairside caries-susceptibility salivary tests, is the most suitable and modern approach to the problem. A review of the literature on salivary tests, at present available, able to identify the factors contributing to caries susceptibility, is presented. Each test is accurately described, with regard both to its procedure and the interpretation of its results:

Dental Caries↗
PubMedDate not supplied

A new surgical technique for fibrosed interventricular septum.

We describe a new surgical technique for the treatment of fibrosed interventricular septum, with or without left ventricular aneurysm. It is designed for patients whose ventriculograms revealed important septal dysfunction. Eleven patients ranging from 37 to 66 years of age were operated upon between 1984 and 1988. The left ventricle was opened through the aneurysm or the anterior wall when only anterior septal fibrosis was present. In patients with large aneurysms, two purse-string sutures were placed on the inside surface of the intact ventricle, around its limits, for approximation. The fibrosed septum was thus excluded from the new ventricular cavity. A patch was placed between the fibrosed and the healthy septum, reaching to the ventricular wall, all around the transitional edge. Both, ventricular geometry and function were improved. All patients were asymptomatic after one year follow-up.

Adult↗
PubMedDate not supplied

Macrophages, synovial tissue and rheumatoid arthritis.

Macrophage-like synoviocytes originate in the bone marrow, like other mononuclear phagocytes, and are constantly replaced via the circulation. In rheumatoid synovium sections, 80-100% of the synovial lining cells are macrophage-like cells functioning as antigen processing- and antigen-presenting cells to T lymphocytes. Monocyte and lymphocyte traffic into the rheumatoid arthritis (RA) synovium is mediated by adhesion molecules such as endothelial-leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecules-1 and -2 (ICAM-1 and ICAM-2), as well as monocyte chemotactic protein 1 (MCP-1) and beta 2 integrins (CD11 a,b,c/CD18). Macrophage-like cells in the RA synovium are highly activated based on their morphology, surface class II HLA antigen expression, and synthesis of cytokines such as interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage CSF, and transforming growth-factor beta (TGF-beta). Evidence for type 1 (higher affinity) and type 2 (lower affinity) androgen (ARs) and estrogen receptors (ERs) on macrophage-like synoviocytes in either male or female synovial samples from both RA patients and controls has been reported. In particular, ERs have also been found on CD8+CD29+ CD45R0+ T lymphocytes (memory), infiltrating rheumatoid synovial tissues. Sex hormones have been found to influence macrophage activity in experimental and clinical conditions such as RA. Generally estrogens have immunostimulatory effects, whereas androgens are immuno-suppressive.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthritis, Rheumatoid↗
PubMedDate not supplied

Sex hormones, proto-oncogene expression and apoptosis: their effects on rheumatoid synovial tissue.

Programmed cell death (apoptosis), is a non-random physiological process characterized by cell fragmentation without leakage of the cellular contents into the extracellular space. Apoptosis is especially important in the immune system. On the other hand the capacity of cells to proliferate and to show local invasiveness, as in cancer cells or the "tumor-like" synoviocytes in rheumatoid arthritis (RA), seems to be controlled by a group of genes called "proto-oncogenes". The early metabolic events in cell apoptosis and proliferation are remarkably similar. The primary location of apoptotic cells in RA synovial tissue is at the level of the synovial lining, varying from rare positive cells to > 50% positive cells. C-jun, c-fos and c-myc oncoproteins seem to be largely restricted to the synovial cells attached to the sites of cartilage and bone destruction. Ovarian follicle atresia could serve as a useful model to study the hormonal regulation of apoptosis in different endocrine tissues. Based on ovarian studies it seems that estrogens generally prevent apoptosis whereas androgens induce apoptosis. The binding of steroids to their receptors forms a complex wherein the receptors are transformed, so that they can then pass through the nuclear membrane and associate with specific recognition sites on DNA. In the majority of cases, the steroid receptors mediate the rapid regulation of the nuclear proto-oncogene transcription. Therefore, they may serve as important "early" regulatory genes and as excellent universal markers in all tissues in steroid hormone action. Since the macrophages are considered to be target cells for sex hormones, we recently evaluated c-myc expression in cytocentrifuge preparations obtained from primary cultures of RA synovial macrophages treated with estrogens, and observed a marked upregulation. Further studies of the influence of sex hormones on synoviocyte apoptosis and proto-oncogene expression should offer new perspectives on the pathogenesis and therapy of synovitis in RA and other rheumatic diseases.

Animals↗
PubMedDate not supplied

Effect of cyclosporin on apoptosis in human cultured monocytic THP-1 cells and synovial macrophages.

OBJECTIVE: Cyclosporin A (CyA) is an immunosuppressant drug used for the treatment of rheumatoid arthritis (RA), that might affect programmed cell death (apoptosis) of the cells involved in the synovial inflammatory reaction. The effects of CyA on apoptosis were evaluated on cultured human monocytic myeloid cells (THP-1 cell line) and on RA synovial macrophages. METHODS: In order to induce THP-1 cell differentiation into adherent cells, an amount of these was treated with human recombinant IFN-gamma before incubation with CyA. Primary cultures of synovial macrophages were obtained from RA patients and treated in vitro with CyA. RESULTS: CyA, at the pharmacological range (100-300 ng/ml) employed in the treatment of RA, seems to induce, after 48-96 hrs, programmed cell death in differentiating THP-1 cells, whereas cultured synovial macrophages (fully differentiated monocytic cells) do not show any apoptosis at the same time. CONCLUSION: Short-term CyA treatment may induce increased apoptosis in immature and differentiating cultured monocytes. Cultured synovial macrophages (resident monocytic-derived and differentiated cells) seem to be resistant to the treatment as far as apoptosis is concerned.

Apoptosis↗