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Biomedical subjects

Rosalia Leonardi

Publications and source records attributed to Rosalia Leonardi.

12 recordsLinked to original sources
PubMed2006

Immunolocalization of CD44s in human teeth.

CD44s (standard form) is an integral membrane glycoprotein, which plays an important role in both cell-cell and cell-substrate adhesion. Few studies have demonstrated that CD44s and its isoforms are involved in mediating cell-cell and cell-substrate interactions in the periodontium and surrounding tissues. The present study was undertaken as so little data are available on its presence in human adult hard dental structures. Six extracted premolars from children, aged 10-12 years, were used in the present study. They were fixed in 10% neutral buffered formalin and decalcified in 7.5% EDTA for 2 weeks. Immunohistochemistry to reveal binding of a monoclonal mouse anti-CD44s was used for the localization of CD44s. The antibody was applied directly onto the tissue section and the slides incubated overnight (4 degrees C) in a humidified chamber. In serial sagittal sections of teeth, binding of anti-CD44s was seen in odontoblasts, periodontal ligament fibroblasts and cementoblasts. Our findings present evidence that CD44s is localized in periodontal ligament fibroblasts, cementocytes and odontoblasts of mature human teeth. CD44s may be involved in tooth cell differentiation and later in cell-matrix interaction and in the accumulation of inflammatory cells in the extravascular connective tissue in these sites.

Child↗
PubMed2006

A sella turcica bridge in subjects with dental anomalies.

Calcification of the interclinoid ligament (ICL) of the sella turcica, or sella turcica bridging, has been associated with severe craniofacial deviations. Despite no comprehensive study on the sella turcica bridge, a relationship with tooth and eruption disturbances has been reported. In order to investigate whether congenital absence of the second mandibular premolar, or the presence of a palatally displaced canine (PDC), is associated with sella bridging, a retrospective study was performed. Lateral cephalometric radiographs from 20 males and 14 females, aged between 8 and 16 years, with a PDC and second mandibular premolar aplasia were reviewed and compared with a control group. A standardized scoring scale was established to quantify the extent of a sella turcica bridge from each radiograph (no calcification, partially calcified, and completely calcified). The prevalence of complete calcification of the ICL in adolescents with dental anomalies was equal to 17.6 per cent, while an incidence 9.9 per cent was found in the control group. A partially calcified sella turcica was observed in 58.8 per cent of adolescents with dental anomalies compared with 33.7 per cent in the control group. The association between the degree of calcification of the ICL and the presence of dental anomalies in the studied adolescents was statistically significant according to chi-square statistics (P = 0.004). This was confirmed by Fisher's exact test (P = 0.003). According to these findings, the prevalence of a sella turcica bridge in adolescents with dental anomalies is increased, while age and gender do not greatly influence ossification of the ICL. The very early appearance during development of a sella turcica bridge should alert clinicians to possible tooth anomalies in life later.

Adolescent↗
PubMed2006

Effect of c-Met expression on survival in head and neck squamous cell carcinoma.

The proto-oncogene c-Met has been suggested to be associated with progression of squamous cell carcinoma of the head and neck. The aims of the present study were to assess the prevalence of c-Met expression in oral squamous cell carcinoma (OSCC) and to verify whether c-Met can be considered a marker of prognosis in these patients. In a retrospective study, a cohort of 84 OSCC patients was investigated for c-Met expression and its cellular localization by immunohistochemistry. After grouping for c-Met expression, OSCC patients were statistically analyzed for the variables age, gender, histological grading, tumor node metastasis, staging and overall survival rate. Univariate and multivariate statistics were used for data analysis. Sixty-nine cases (82.2%) of OSCC showed immunopositivity, with a mainly membranous expression and scattered areas also showing a cytoplasmic localization, whereas 15 cases (17.8%) did not show c-Met. No statistical association was found between c-Met expression and any variables considered at baseline, apart from the higher number of c-Met positivity in females (p = 0.026). Among positive tumors, well-differentiated areas showed low or absent cytoplasmic expression, while low-differentiated areas showed both membranous and cytoplasmic positivity. In terms of prognostic significance, c-Met expression was found to have an independent association with a poorer overall survival rate (p = 0.036). On the basis of these results, it is possible to suggest c-Met as an early marker of poor prognosis, a hallmark of aggressive biological behavior in OSCC, suggested to be useful in identifying cases of OSCC before the relapse.

Adolescent↗
PubMed2005

p63 overexpression associates with poor prognosis in head and neck squamous cell carcinoma.

p63 belongs to a protein family that includes 2 structurally related proteins, p53 and p73. The aim of this study was to investigate the biologic role of p63 in oral tumorigenesis and its possible role as prognostic marker in oral cancer. Ninety-four cases of oral squamous cell carcinoma and 10 cases of normal mucosa were analyzed for p63 expression by immunohistochemistry. Normal oral mucosa showed a basal and parabasal expression of p63. Five (5.3%) cases of oral cancer showed less than 10% of positive tumor cells; in 33 (35.1%) cases the positive tumor cells comprised between 10% and less than 30%, in 36 (38.3%) cases the positive tumor cells comprised between 30% and less than 50%, and in 20 (21.3%) cases the positive tumor cells were more than 50%. There was also a statistically significant correlation between p63 expression and tumor differentiation: p63 expression was amplified in poorly differentiated tumors (P < .05). When analyzed for prognostic significance, patients with perineural infiltration had poorer survival rates than the group with no perineural infiltration (P < .05) and patients with increased p63 expression had poorer survival rates than the group with reduced p63 expression (P < .05). The statistical analysis showed no significant correlation between p63 expression, sex, age, tumor size, staging, recurrence, and metastasis. Cases with diffuse p63 expression were more aggressive and poorly differentiated and related to a poorer prognosis. These data suggest that p63 expression may be useful to identify cases of oral squamous cell carcinoma with more aggressive and invasive phenotype providing novel diagnostic and prognostic information on individual patient survival with oral cancers.

Adolescent↗
PubMed2004

Interactive online program to improve cephalometric tracing skills.

Cephalometric analysis has a key role in orthodontic clinical practice and research. The skills needed to accurately trace radiographs can be acquired only through practice. We developed an interactive, Internet-based system to help students hone their cephalometric tracing skills. The online system allows students to practice any time and at their own pace, and receive immediate graphical feedback on the quality of their work. It also allows instructors to update the collection of cases available to students for practice.

Cephalometry↗
PubMed2004

Fibronectin upregulation in human temporomandibular joint disks with internal derangement.

Fibronectin is a large fibril-forming extracellular glycoprotein that seems to be involved in joint diseases. The objective of this study was to investigate the expression of fibronectin in human temporomandibular joint disks obtained from patients with internal derangement and varying extents of disk tissue degeneration/regeneration with that of temporomandibular joint disks free of significant morphological alterations by means of immunohistochemical methods. Twelve adult human temporomandibular joint disks (10 diseased disks and 2 normal disks) were used in this study. Temporomandibular joint disks were fixed in 10% buffered formalin. Sections were then immunohistochemically processed using a monoclonal antibody specific to human fibronectin and streptavidin-biotin detection methods. Positive reactions to fibronectin were found in normal and diseased disk tissues but to a different extent. Normal disk tissues revealed weak fibronectin expression, which was mainly located along the collagen bundles. Temporomandibular joint disks with internal derangement exhibited a higher immunoreactivity. Distinct reticular fibronectin structures were found inside the diseased disk, particularly nearby the newly formed blood vessels, tears, and clefts. In the covering layer of the disk surface, fibronectin was expressed in a fascicular pattern running parallel to the disk surface. The findings suggest that temporomandibular joint disk tissue can express fibronectin and that the expression is more pronounced in disk specimens of patients with internal derangement of the temporomandibular joint, supporting a role of this glycoprotein in the degeneration/regeneration processes of human temporomandibular joint disk tissue.

Adult↗
PubMed2003

Palatally displaced canine anomaly in monozygotic twins.

The palatally displaced canine (PDC) anomaly is a tooth malposition occurring in 1% to 3% of most populations. From the results of family studies, the PDC phenotype appears to be under strong genetic influence. In this study we report monozygotic (MZ) twin girls with bilateral PDC expression. The finding of PDC anomaly in MZ twins--to our knowledge, the first such published case--lends further support to evidence of genetic control of the PDC anomaly.

Child↗
PubMed2003

Intracapsular fractures of mandibular condyle: diagnosis, treatment, and anatomical and pathological evaluations.

The aim of this study was to attempt to establish a correlation between condylar localized fracture, onset of anatomicopathological lesions of the articular structures, and determination of ankylosis so as to define appropriate diagnostic and therapeutic procedures. Clinical, arthroscopic, and histological studies were carried out in two patients with a severe temporomandibular joint disorder after a condylar localized fracture. Treatment included removal of the displaced fragments, condylar surface remodeling, suture of retrodiskal perforations, and diskal repositioning. The histological study of the condylar specimens revealed signs of osteoarthrosis of the articular surface and chondroid metaplasia of the bilaminar zone with early onset of ankylosis. Results of this study confirmed the presence of causal relations between condylar localized fracture and ankylosis with alterations in retrodiskal tissue. These relations are found in 1) tissue damage caused by bony fragments remaining in the articular cavity (underestimated and poorly treated fractures), 2) the lesion that occurs in association with mechanical trauma; and, particularly, c) the disk and retrodiskal impairments caused by catabolic and degenerative osteoarthrotic changes secondary to condylar marrow damage. Thus, timeliness and accuracy of the diagnosis of condylar localized fracture are most important, as are correct diagnosis and treatment before the onset of degenerative anatomicopathological lesions.

Adult↗
PubMed2002

Expression of heat shock protein 27 (HSP27) in human temporomandibular joint discs of patients with internal derangement.

Heat shock proteins (HSPs) are believed to represent a cellular stress response mechanism that protects intracellular proteins from damaging events. Some studies have demonstrated an enhanced expression of large-molecular-weight HSPs in diseased systematic joints. Small heat shock proteins, and among these HSP27, have been studied to a lesser extent. HSP27 has cytoprotective and biosynthetic functions within chondrocytes, and it is an estrogen-associated protein that is under hormonal modulation. To improve understanding at a molecular level of the pathophysiology of certain temporomandibular joint disorders, the authors carried out this immunohistochemical study to assess the presence of HSP27 in human TMJ discs. Twelve adult human TMJ discs (10 diseased and 2 healthy discs) and 5 TMJ fetal human discs were used in this study. Adult discs and TMJ tissues of human fetuses were fixed in 10% buffered formalin. Samples were then processed for histologic examination. Sections were immunohistochemically stained using the streptavidin-biotin detection method. No reaction product for HSP27 in the discs of fetuses was noted. HSP27 was weakly expressed in normal TMJ discs and highly up-regulated in discs of patients showing new vessel formation and chondroid metaplasia. Any correlation between gender and HSP27 was found in the sample, being the up-regulation of HSP27 related mostly to major histopathological changes. This different pattern of HSP27 immunostaining in human TMJ discs detected in the authors' specimens suggests that the expression of this small HSP is functionally modulated. In fact HSP27 up-regulates in internal derangement specimens with major histopathological changes; on the other hand, it is not expressed or only weakly expressed in TMJ discs of fetuses and normal TMJ discs.

Adult↗
PubMedDate not supplied

Prognostic value of HSP27 in head and neck squamous cell carcinoma: a retrospective analysis of 57 tumours.

BACKGROUND: The aims of the present study were to assess the prevalence of HSP27 expression in oral squamous cell carcinoma (OSCC) and to verify whether HSP27 can be considered to be a marker of prognosis in patients with OSCC. MATERIALS AND METHODS: The immunohistochemical expression of HSP27 was evaluated in 57 OSCC, who received standard treatment and monitoring. After grouping for HSP27 expression, OSCCs were statistically analysed for the variables age, gender, histological grading, TNM, staging and survival rate. Univariate and multivariate analyses were performed. RESULTS: HSP27 was found to be reduced in 31 OSCC and was normally expressed in 26 OSCC. The pattern and intensity of HSP27 immunolabelling did not show significant differences in relation to any variables retrospectively considered. In terms of prognostic significance, HSP27 reduced expression was found to have an independent association with the poorest overall survival rate (p=0.009; OR= 4.404; CI=1.444:13.427 by Cox regression). CONCLUSION: HSP27 reduced expression is an early marker of poor prognosis, useful in identifying aggressive biological behaviour in OSCC cases even before relapse.

Adolescent↗