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Biomedical subjects

F R Grassi

Publications and source records attributed to F R Grassi.

7 recordsLinked to original sources
PubMed2005

T cells support osteoclastogenesis in an in vitro model derived from human periodontitis patients.

BACKGROUND: Periodontitis is characterized by alveolar bone destruction; however, the mechanisms responsible for bone damage are poorly understood. It has been reported that T cells are implicated in the pathogenesis of periodontitis. It has been also demonstrated that activated T lymphocytes secrete receptor activator of nuclear factor-kappa B ligand (RANKL) and can support the differentiation of monocytes into resorbing osteoclasts (OCs). Therefore, the purpose of this study was to examine the OC formation in periodontitis patients (PP) and the role of T cells in osteoclastogenesis. METHODS: To study OC formation, we used an in vitro model consisting of unstimulated and unfractionated peripheral blood mononuclear cells (PBMCs) from PP and controls. In parallel, T-cell-depleted PBMCs from the same patients were also established. The expression of RANKL and tumor necrosis factor-alpha (TNF-alpha) was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot in fresh T cells isolated from PP and controls. Functional antibodies, anti-RANKL and anti-TNF-alpha, were utilized to study osteoclastogenesis in PBMC cultures from PP. RESULTS: We showed that, in unfractionated PBMCs from PP, the OCs spontaneously developed in a T-cell-dependent way. The addition of macrophage colony stimulating factor (MCSF) and RANKL was necessary to promote the osteoclastogenesis in T-cell-depleted PBMC cultures from PP and in unfractionated PBMCs from periodontally healthy controls. Moreover, freshly isolated T cells from PBMCs of PP overexpressed RANKL and TNF-alpha. Finally, functional anti-RANKL and anti-TNF-alpha antibodies significantly inhibited osteoclastogenesis. CONCLUSION: Our data suggest that T cells support spontaneous osteoclastogenesis in PP via RANKL and TNF-alpha overexpression.

Adult↗
PubMed2004

[Alveolar ridge augmentation by means of onlay grafts harvested from mandibular symphysis].

AIM: Prosthestic-implant rehabilitation in subjects partially, or totally, endentulous is the method of choice for the considerable advantages involved from an aesthetic as well as functional point of view, besides preventing the physiological reabsorption that is established in the edentulous area. However, it is necessary to have an adequate quantity, as well as quality, of bone in order to support the fixture and the masticating load, conditions that up to now could often prove inferior for various reasons. Such a randomized research programme was proposed, in order to increase the bone volume by means of grafted onlays in the mandibular/chin area, with implant positioning 6 months after the operation, as a valid solution to the prosthestic problems found in the bone deficiency area. METHODS: Twenty patients with partial edentulism in the incisor-canine area were chosen. They showed no signs of periodontal diseases, bruxism or parafunctions. They underwent an autogenesis bone graft with the bone being taken from the mandibular/chin area, with positioning of the implant 6 months after the first operation, thus obtaining an increased bone height of 5 to 7 mm. RESULTS: Check ups were carried out in the 1(st) week after surgery, once a month for the first 3 months and then every 6 months and showed a minimal degree of bone reabsorption and an excellent osteo-integrative process. CONCLUSION: The use of onlay autogenous bone, compared to the other methods for increasing bone volume, is a valid solution for prosthetic-implant rehabilitation in edentulous areas.

Adult↗
PubMed2003

[Role of human viruses in the pathogenesis of periodontal disease].

Human viruses play a fundamental role in the pathogenesis of periodontal disease due to their intrinsec capacity to interfere with immune system of the host. Herpesvirus maybe involved in the onset or progress of a number of periodontal diseases while HIV seems to be related to the linear gingival erythema (LGE) and necrotizing ulcerative periodontitis (NUP).

Gingival Crevicular Fluid↗
PubMedDate not supplied

Implant surface and osseointegration.

Oral rehabilitation by means of osteointegrated implants is gaining more and more importance, in particular due to the improved characteristics of the fixture: among these, the superficial microscopical morphology plays a role of primary importance, since it can influence the evolution of the osteointegrative process. Therefore, this led to many surface treatments which can improve the quality and the speed of formation of the bony tissue. The aim of this paper is a review of the literature on this topic in order to find out which processes of characterization of the surface implant are now available and which results can be obtained.

Dental Implants↗
PubMedDate not supplied

Gingival overgrowth in renal transplant recipients induced by pharmacological treatment. Review of the literature.

Patients who undergo a renal transplant also require a pharmacological immunosuppressor therapy with cyclosporine (CsA) as well as anti-hypertensive calcium channel-blockers (CCBs); the former suppresses interferon and interleukin-2 production thus interfering with T cell cell-mediated activity, while the latter are used in order to counteract the nephrotoxicity of CsA which causes the local release, of thromboxane A2 with vascular vasoconstriction in the kidney. The use of both these drugs, particularly if used in association, leads to the onset of a clinical picture of variable entity, characterized mainly by a hypertrophy originating usually at the level of interdental papillae, and more pronounced in the anterior maxillary areas and the vestibular surfaces of the teeth, in a more or less symptomatic manner. The therapy is above all preventive, with an appropriate oral hygiene program, both professionally as well as at home, and with the use of substitutive drugs that do not present such side effects.

Angiotensin-Converting Enzyme Inhibitors↗
PubMedDate not supplied

Interleukin-7 production by B lymphocytes affects the T cell-dependent osteoclast formation in an in vitro model derived from human periodontitis patients.

Periodontitis is characterized by irreversible destruction of alveolar bone and connective tissue attachment in the periodontium. We recently reported that T cells support the osteoclastogenesis by the overproduction of nuclear factor-kappa-B-ligand (RANKL) and Tumor Necrosis Factor-alpha (TNF-alpha) in an in vitro osteoclastogenesis model from periodontitis patients (Pp). It is known that IL-7 stimulates the production of osteoclastogenic factors by T cells and IL-6 potentiates IL-7 expression. Thus, we studied the involvement of IL-6 and IL-7 in the T cell regulation of osteoclast (OC) formation, in an in vitro osteoclastogenesis model from Pp. We demonstrated high levels of IL-7 in both the media collected from PBMC cultures of Pp and the sera of the same patients. We also demonstrated that freshly isolated B cells from PBMCs of Pp were the source of IL-7 in our model. B cells, in fact, overexpressed IL-7 at mRNA and protein levels, and this production was up-regulated by IL-6. Moreover, the OC formation decreased in the presence of anti-IL-6 and IL-7 functional antibodies in PBMC cultures from Pp. These data suggest that B cells could be responsible for the T cell-dependent osteoclastogenesis in periodontitis through the involvement of IL-6 and IL-7.

Adult↗