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Biomedical subjects

G Iezzi

Publications and source records attributed to G Iezzi.

At least 19 recordsLinked to original sources
PubMed2006

CD10 expression in stromal cells of oral cavity squamous cell carcinoma: a clinic and pathologic correlation.

OBJECTIVE: CD10 is expressed on the majority of follicle-center lymphomas and Burkitt lymphomas. CD10 has also been shown to be present in a variety of other neoplasms. DESIGN: The aim of this study was a correlation of CD10 and several parameters: age, tumor size, presence of lymph node metastases, clinic stage, histologic grading, presence of local recurrences. MATERIALS AND METHODS: The tissues of 77 consecutive patients with oral cavity squamous cell carcinoma were evaluated using immunostaining with monoclonal antibody for CD10. MAIN OUTCOME MEASURES: Highly significant correlations were found with the lymph node status, the presence of local recurrences and the histologic grading. The presence of CD10-positive cells was not correlated with the age of patients, tumor size and clinic stage. RESULTS: The results of the present study show that in oral squamous cell carcinoma CD10 positivity is an indicator of worse prognosis. Another strong correlation was found with the presence of local recurrences. Also the histologic grade was significantly correlated with the CD10 positivity. CONCLUSION: Our results point to the fact that CD10 expression can, perhaps, have an important role in tumor invasion, probably facilitating the occurrence of metastases.

Adult↗
PubMed2006

Microvessel density and vascular endothelial growth factor expression in sinus augmentation using Bio-Oss.

AIM: The aim of this study was to evaluate microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression in sinus augmentation with Bio-Oss. METHODS: Twenty patients participated in this study. The sinuses were filled with 100% Bio-Oss. Implants were inserted after 3 months in group A, and 6 months in group B. A trephine was used to harvest bone cores. As control, the pre-existing subantral bone was used. RESULTS: The mean MVD in control bone was 23.6 +/- 1.8. In the sites augmented with Bio-Oss, at 3 months, the MVD was 23.3 +/- 2.1, while in the sites retrieved at 6 months the MVD was 29.5 +/- 2.4. The difference in MVD between the control bone and group A was not statistically significant. The difference between the control bone and group B was statistically significant (P < 0.05). The statistical analysis showed that the difference in MVD between group A and group B was statistically significant (P < 0.05). CONCLUSIONS: Bio-Oss seemed to induce an increase in MVD that reached a higher value after 6 months. The percentage of vessels positive to VEGF was higher in group A than in group B. Our data also showed a higher percentage of vessel and stromal cells positive to VEGF and higher MVD values in areas where there was newly formed bone compared with areas where maturation processes were occuring, and this fact could point to a close spatial relationship between angiogenesis and osteogenesis.

Adult↗
PubMed2006

Pleomorphic lipoma of the oral cavity. Report of a case.

Pleomorphic lipoma (PL) is a rare benign tumor mainly located in the upper back, upper shoulders, and back of the neck in elderly men. More rarely it is located in the head and neck region and in the oral cavity. The differential diagnosis should be made with sclerosing liposarcoma and well-differentiated liposarcoma. A 59-year-old male patient was referred for the presence of a lesion involving the marginal and adherent gingiva of teeth # 5; this lesion extended into the vestibular mucosa. The lesion had a 2 cm diameter, showed no tenderness, had a hard-parenchymatous consistency, was mobile on the underlying tissues and was covered by normal appearing mucosa. Under local anesthesia, the lesion was completely removed. A free gingival graft from the palate was used to cover the defect. Microscopically, it was possible to observe mature adipocytes, spindle cells and rare ''floret-like'' cells. Lipoblasts and mitoses were absent. The definitive pathologic diagnosis was pleomorphic lipoma. No recurrences were present after a 5 years follow-up. Local excision is adequate for PL and the tumor does not recur.

Adipocytes↗
PubMed2002

Sebaceous adenoma of the cheek.

Sebaceous adenoma is a tumour only rarely located in the oral cavity. Less than 10 cases have been reported. Sebaceous adenoma represents 0.5-0.7% of all monomorphic adenomas. Sebaceous adenoma is mainly constituted by two types of cells, undifferentiated peripheral basaloid cells and cells showing different degrees of sebaceous differentiation located in the center of the lesion. The differential diagnosis must be made with sebaceous hyperplasia. Sebaceous adenomas are benign, and they do not recur after a conservative excision.

Adenoma↗
PubMed2002

Clear cell odontogenic carcinoma.

Clear cell tumours, in the head and neck region, are usually derived from salivary or odontogenic tissues, or may be metastatic. A few clear cells may be present in odontogenic cysts, while, odontogenic neoplasms composed predominantly of clear cells are quite rare. They include calcifying epithelial odontogenic tumours (CEOT), ameloblastoma and odontogenic carcinoma. Clear cell odontogenic tumour (CCOT) has been classified in the last WHO classification as a benign tumour, but it is now recognized as a more sinister lesion and current opinion is that CCOT should be designated as a carcinoma. These tumours are characterized by aggressive growth, recurrences, and metastatic disease. A recent review of the literature has yielded 30 cases of tumours with similar characteristics. These tumours have a peak incidence in the 5th-7th decades, with a female predilection. The anterior portions of the jaws, especially the mandible, are most frequently affected. The aggressive potential of these neoplasms is well documented by the extensive invasion of adjacent tissues, multiple recurrences and regional or distant metastases.

Adenocarcinoma, Clear Cell↗
PubMed2001

Migration and function of antigen-primed nonpolarized T lymphocytes in vivo.

Upon antigenic stimulation, naive T lymphocytes proliferate and a fraction of the activated cells acquire a T helper cell type 1 (Th1) or Th2 phenotype as well as the capacity to migrate to inflamed tissues. However, the antigen-primed T cells that receive a short T cell receptor (TCR) stimulation do not acquire effector function and remain in a nonpolarized state. Using TCR transgenic CD4(+) T cells in an adoptive transfer system, we compared the in vivo migratory capacities of naive, nonpolarized, Th1 or Th2 cells. Although all cell types migrated to the spleen, only naive and nonpolarized T cells efficiently migrated to lymph nodes. In addition Th1, but not Th2, migrated to inflamed tissues. In the lymph nodes, nonpolarized T cells proliferated and acquired effector function in response to antigenic stimulation, displaying lower activation threshold and faster kinetics compared with naive T cells. These results suggest that nonpolarized T cells are in an intermediate state of differentiation characterized by lymph node homing capacity and increased responsiveness that allows them to mount a prompt and effective secondary response.

Animals↗
PubMed2001

Osteolipoma of the tongue.

Lipomas are common, benign tumours located in any part of the body in which fat is normally present. Some variants of lipoma have been described according to the type of tissue present. A rare variant consists of a lipoma with osseous or cartilaginous metaplasia. These lesions have been called chondrolipoma, osteolipoma, lipoma with chondroid or osseous metaplasia, lipoma with cartilaginous or osseous change, or ossifying lipoma. We present the case of an osteolipoma of the tongue in a 49-year-old female who was referred for a painless mass on the left lateral margin of the tongue, and present for about 8 years. Osteolipomas have been reported in middle-aged or elderly patients with a very long clinical history. These tumours tend to be large and to arise from the deep soft or subcutaneous tissues. The cartilage and bone is probably produced by metaplasia of fibroblasts in chondroblasts or osteoblasts. These lesions are benign and do not recur.

Diagnosis, Differential↗
PubMed2001

Oral focal mucinosis of the gingiva: case report.

BACKGROUND: Oral focal mucinosis is a rare disease of unknown etiology, where the connective tissue undergoes a focal myxoid degeneration. METHODS: We describe a 48-year-old patient who was referred for a firm, tender mass located on the gingiva of the left central mandibular incisor. The first clinical impression at examination was that of a periodontal abscess. RESULTS: The lesion underwent a biopsy, and the final microscopic diagnosis was oral focal mucinosis. CONCLUSIONS: It must be stressed that in most focal gingival lesions, a preoperative diagnosis can be almost impossible.

Diagnosis, Differential↗
PubMed2000

Spindle-cell lipoma of the cheek: a case report.

Spindle-cell lipoma (SCL) is a distinct histological variant of lipoma. Clinically, it appears as a solitary, subcutaneous, circumscribed lesion. SCL accounts for about 1.5% of all adipocytic tumours. Only nine cases of intraoral SCL were found in the literature. Microscopically, mature adipocytes and spindle cells are immersed in a myxoid stroma. SCL needs only local excision, and it does not recur.

Cheek↗
PubMed2000

Implant periapical lesion: a clinical and histologic case report.

A new pathologic entity called implant periapical lesion has been recently described. This lesion could be produced by contamination of the implant surface, overheating of bone, overloading of the implant, presence of a pre-existing bone pathology, presence of residual root fragments and foreign bodies in bone, implant placement in an infected maxillary sinus, implant placement in a poor bone quality site, or lack of biocompatibility. A 49-year-old female patient underwent the placement of a screw-shaped titanium dental implant in the premolar region of the right mandible Six months after implant insertion, the patient presented with a persistent pain resistant to analgesics. No fistula was present at a clinical intraoral examination. A periapical x-ray showed the presence of a radiolucency at the apical portion of the implant; this image was confirmed by a CT Scan. The implant was removed. After implant removal, the pain disappeared completely. The specimen was processed to obtain thin ground sections. The histologic examination showed the presence of necrotic bone in the external and apical portion of the antirotational hole of the implant. The etiology of the implant failure in this instance could be related, probably, to an implant contamination of the apical portion of the implant.

Dental Implantation, Endosseous↗
PubMed2000

Immediate postextraction implants: a histologic and histometric analysis in monkeys.

The aim of this study was to evaluate the reaction of peri-implant tissues to immediately placed titanium plasma-sprayed implants into extraction sockets. Six macaca fascicularis monkeys were used in the study. A total of 36 titanium plasma-sprayed implants (PHI, Legnano, Italy) were inserted in both arches (18 in the posterior maxilla and 18 in the posterior mandible). The two premolars and the first molars of the maxilla and the mandible of all animals were extracted, and immediate postextraction implants were placed. After a releasing periosteal incision, the flap was coronally repositioned and sutured. No barrier membranes were used, and the only graft material used was autogenous bone chips. The implants were loaded after 2 months. Six months after implant loading, a block section was carried out, the remaining defects were filled with nonresorbable hydroxyapatite, and all 36 implants were retrieved. The implants were treated with the Precise System (Assing, Rome, Italy), to obtain thin ground sections. A total of three slides were cut for each implant and were examined under normal and polarized light. A histomorphometrical analysis was done. All implants were covered by compact, mature bone under examination in light microscopy. A very high bone-implant contact percentage (65-70%) was observed. No bone loss was present after the loading period. These results indicate that implants placed into fresh extraction sites grafted with autogenous bone chips will heal in a predictable way.

Animals↗
PubMed1999

Immunogenicity of apoptotic cells in vivo: role of antigen load, antigen-presenting cells, and cytokines.

Apoptosis allows the clearance of unwanted cells from living tissues without causing inflammation. Processing of phagocytosed apoptotic cells yields Ags that access the cytosol and the MHC class I pathway of engulfing cells and are recognized by Ag-specific CTL. We show here that injection of apoptotic RMA cells, a syngeneic T cell lymphoma, into C57BL/6 mice results in priming of a functional and long-lasting tumor-specific immune response. Cross-priming of CTLs by apoptotic cells requires CD4+ T cell help. Apoptotic cells, however, are at least 20-fold less immunogenic than nonreplicating live cells. Immunogenicity of apoptotic cells is proportional to the number of cells injected, correlates with the serum concentration of IL-10 and IL-1beta cytokines, and is enhanced in IL-10 knockout mice. Moreover, immunization with dendritic cells (DCs), but not macrophages (Mphi), pulsed with apoptotic cells primes tumor-specific CTLs and confers protection against a tumor challenge. Our findings demonstrate that tumor cells undergoing apoptosis are, though scarcely, immunogenic in vivo, outline the different roles of Mphi and DCs in the physiologic clearance of unwanted cells, and have implications in designing immunomodulating vaccines.

Adoptive Transfer↗
PubMed1999

The interplay between the duration of TCR and cytokine signaling determines T cell polarization.

Development of Th1 and Th2 effector lymphocytes is driven primarily by IL-12 or IL-4, but is also influenced by the strength of antigenic stimulation. However, the mechanism by which TCR signaling contributes to T cell polarization remains elusive. We show that in the presence of IL-12 a short TCR stimulation can lead to efficient Th1 polarization and IL-12 exerts its effect when present during, as well as after, TCR signaling. In contrast, Th2 polarization requires a prolonged TCR stimulation and IL-4 is effective only when present during the period of TCR triggering. The simultaneous stimulation by TCR and IL-4 is required to induce demethylation of IL-4 and IL-13 genes that accompanies the stochastic generation of Th2 cells producing either or both cytokines. Thus, the duration of TCR stimulation represents a crucial parameter that influences the response to polarizing cytokines and the acquisition of T cell effector functions.

Animals↗
PubMed1999

Role of antigen-presenting cells in cross-priming of cytotoxic T lymphocytes by apoptotic cells.

Although the mechanisms regulating recognition and phagocytosis of apoptotic cells by scavenger cells are the subject of intense investigation, little is known about the fate of the antigens contained in apoptotic cells and the constraints defining their immunogenicity. We developed a model in C57BL/6 mice to evaluate whether phagocytosis of apoptotic tumor cells yielded antigens able to get access to the MHC class I pathway and activate a specific cytotoxic T lymphocyte response. Our results demonstrate that apoptotic tumor cells are antigenic in vitro and can be immunogenic in vivo. Their immunogenicity depends on the number of cells used for immunization and the antigen-presenting cells involved in processing and presentation of antigens contained in the dying cells. The demonstration of the immunogenicity of apoptotic cells may have direct implications both in autoimmunity and cancer.

Animals↗
PubMed1999

Cancer immunotherapy: synthetic and natural peptides in the balance.

The identification of human tumor-associated antigens has opened new avenues for immune intervention in cancer. Clinical trials using synthetic peptides that match segments of known tumor-associated proteins are ongoing. Alternatively, naturally processed peptides, obtained by acid treatment of tumor cells can be used. Here, Matteo Bellone and colleagues discuss the advantages and disadvantages of synthetic versus natural tumor peptides in cancer immunotherapy.

Amino Acid Sequence↗
PubMed1998

The duration of antigenic stimulation determines the fate of naive and effector T cells.

It is known that T cells engage antigen-presenting cells (APCs) in a stable interaction that results in sustained TCR signaling. We show here that the duration of this process is critical in determining whether T cells will be activated or deleted. Whereas naive T cells require approximately 20 hr of sustained signaling to be committed to proliferation, effector T cells become committed after only 1 hr but die following activation if antigenic stimulation is prolonged. Costimulation by anti-CD28 facilitates T cell activation by decreasing the time of commitment and by protecting T cells from death. These findings explain in quantitative terms the essential requirement for professional APCs in T cell priming and show that the duration of antigenic stimulation is the major factor determining the fate of naive and effector T cells.

Animals↗
PubMed1997

Processing of engulfed apoptotic bodies yields T cell epitopes.

Programmed death via apoptosis is the metazoan physiologic mode of cell death. Apoptotic cells are recognized by scavenger phagocytes via a number of membrane receptors and engulfed. Thereafter, little is known of their fate, or that of phagocytes. Here, we have traced apoptotic cells upon their engulfment by macrophages. After 3 h, apoptotic cells were contained in discrete well-defined vacuoles. Upon overnight chase, several small vesicles, possibly originating from the fragmentation of original vacuoles, were evident all over the macrophage body. Furthermore, Ags were diffused in the cytosol of some cells, which raises the possibility that epitopes from engulfed apoptotic cells may associate with macrophage MHC class I molecules and be recognized by T lymphocytes. Indeed, Ag-specific CTLs recognize and specifically lyse syngeneic macrophages upon phagocytosis of MHC class I-positive or -negative apoptotic cells, provided that they contain the relevant Ags. Synthesis and membrane expression of class I molecules by macrophages, together with functional transporters associated with Ag presentation, were necessary for recognition and lysis. The indirect presentation of epitopes from engulfed apoptotic cells by scavenger Ag-presenting phagocytes may, in the absence of "danger" signals, have implications for the establishment of central and peripheral self-tolerance.

Animals↗