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Biomedical subjects

L Fonzi

Publications and source records attributed to L Fonzi.

At least 19 recordsLinked to original sources
PubMed2005

Nestin expression in normal adrenal gland and adrenocortical tumors.

Human adrenocortical cells have been shown to express cytokeratins and vimentin. Nestin is an intermediate filament protein that is mainly expressed in the developing nervous system and that has been recently reported in rat adrenal gland as well. Using immunohistochemical and biochemical approaches, the present study demonstrates that nestin is constantly expressed in situ in the cortex of normal human adrenal glands. Nestin expressing cells were prevalently located in the zona reticularis but some positive cells could be spotted in the zona fasciculata as well. Moreover, patches of nestin-positive cells have been constantly detected on sections of cortical adenomas. In contrast, adrenal carcinomas displayed a variable number of nestin-immunoreactive cells that in some cases were virtually absent. Samples of renal clear cell carcinoma metastasis in the adrenals were also examined which did not show nestin-immunoreactivity. We propose that a positive nestin-immunoreaction could be useful in differential diagnosis of clear cell tumors in adrenal glands.

Adenocarcinoma, Clear Cell↗
PubMed2004

Comparison of differentiation markers between normal and two squamous cell carcinoma cell lines in culture.

This study examines differences between cultures of normal human oral epithelial cells and two squamous cell carcinoma cell lines (SCC15 and SCC25) in the expression of structural proteins, adhesion molecules, plasma membrane lipid composition, and intercellular junctions. Based on immunocytochemistry, most normal cell cultures appeared to express more E-cadherin, integrin beta-1, cytokeratin (CK) 14, CK19, and involucrin than SCC cultures. By Western blot analysis, normal cultures expressing high levels of E-cadherin also expressed high levels of involucrin and low levels of CK19. Both SCC cultures demonstrated lower expression of E-cadherin and involucrin, whereas only SCC15 cells showed high levels of CK19. Expression of beta-catenin, an E-cadherin associated protein with potential oncogene function, did not vary among normal and SCC cells. Proportions of saturated fatty acids quantified by thin layer chromatography were higher in the normal cell cultures, than in both SCC cell lines. No morphological differences were evident by transmission electron microscopy (TEM) between normal and SCC cell-cell intercellular junctions. Although no quantitation was attempted, observation suggested that normal cells form more intercellular junctions (TEM observation) and larger intercellular bridges (SEM observation) compared to both SCC cell lines. Of the factors examined, main variations between cultures of normal oral epithelium and the two SCC cell lines examined include the expression of structural and adhesion proteins, lipid composition, and intercellular junctions. The extent of the differences varies according to the stage of terminal differentiation demonstrated by the normal cell cultures.

Biomarkers, Tumor↗
PubMed2003

Angiotensinogen localization and secretion in the rat pancreas.

Renin and angiotensinogen have been previously found in the rat pancreas, and angiotensin receptors have been located in the apical domain of duct cells. To evaluate the possibility that angiotensin II could be generated within the duct system, we decided to determine whether angiotensinogen is present in rat pancreatic juice and the angiotensinogen-immunoreactive pancreatic cell types that could be responsible for its production. Angiotensinogen was detected in significant amounts by Western blotting in pancreatic juice collected from several individual rats. Different isoforms between plasma and pancreatic juice angiotensinogens were demonstrated by isoelectric focusing. Immunocytochemical experiments revealed angiotensinogen-immunoreactive cells at the periphery of the islets of Langerhans, and confocal microscopy demonstrated that most angiotensinogen-immunoreactive cells were glucagon-secreting cells. Secretion of angiotensinogen did not follow the regulated secretory pathway since it was absent from the glucagon-containing granules. This was confirmed by electron microscopy immunocytochemistry. Duct and acinar cells did not express angiotensinogen at an immunocytochemical detectable level. The present findings indicated an exocrine secretion of angiotensinogen by glucagon-secreting cells and suggest that one of the final targets of the local pancreatic renin-angiotensin system may be the duct epithelium.

Angiotensinogen↗
PubMed2002

Release of mercury from dental amalgam and its influence on salivary antioxidant activity.

Dental amalgam fillings are known to release significant amounts of mercury (Hg) in saliva which could represent a continuous source of oxidative damage to mouth tissues. The present investigation was aimed at verifying this hypothesis by determining a possible correlation between salivary Hg levels and salivary total antioxidant activity (TAA), which is used as an index of oxidative stress. Samples of saliva from 34 healthy donors were analyzed for Hg content, by vapor atomic absorption spectrometry, and for TAA, by determining the ferric reducing ability ('FRAP' method). A significant correlation between Hg and the number of amalgam restorations or total amalgam surface was evident in both the male and female subjects. A significant negative correlation between TAA and Hg levels or number of amalgam restorations or amalgam surface was evident in females, indicating that small increases in salivary Hg were sufficient to produce a decrease in salivary TAA. On the other hand, no significant correlation was found in the males. The present study provides, for the first time, evidence of a pro-oxidant role of the amalgam Hg chronically released in saliva.

Adolescent↗
PubMed2002

Subcellular localization of beta-catenin in malignant cell lines and squamous cell carcinomas of the oral cavity.

BACKGROUND: Beta-catenin, an E-cadherin-associated protein involved in cell-cell adhesion and signaling, has been hypothesized to translocate to the nucleus and activate transcription in several human cancers, including oral squamous cell carcinomas (OSCC). METHODS: In the present study, we analyzed the subcellular localization of beta-catenin in cultures of human oral normal and malignant (cell lines SCC15 and SCC25) keratinocytes and in 24 frozen samples of oral squamous cell carcinomas by a double-staining technique for nucleic acids and beta-catenin. Growth potential, as assessed by cell count at different time periods, was established for normal, SCC15 and SCC25 cell lines; oral squamous cell carcinomas were classified according to the histopathological and malignancy indexes. RESULTS: Beta-catenin localized at the plasma membrane in the normal and SCC15 cells, not in the SCC25 cells, where it localized mostly in the perinuclear and nuclear areas. In the growth assays, SCC25 cell lines proliferated faster than in normal and SCC15 cells over a period of 6 days (cell numbers were significantly different, P < 0.0001). Carcinoma sections showed a combination of membranous, cytoplasmic and, in few invading epithelial islands of two tumors, nuclear localization of beta-catenin. CONCLUSIONS: In oral squamous cell carcinomas, nuclear beta-catenin staining was observed only within invading islands of two carcinomas deep in the underlying connective tissue. On the basis of this study, we conclude that intranuclear beta-catenin does not appear to be a common finding in oral squamous cell carcinomas and that a clear association between intranuclear beta-catenin and histopathological and malignancy indexes in vivo could not be established.

Adolescent↗
PubMed2001

Pancreatic lymphatic system in rodents.

The lymphatic network of the pancreas has been little investigated and recent studies have provided contrasting data. This research is aimed to supply the morphologic basis to outline the involvement of the lymphatic system in pancreatic pathology. Guinea pigs, rats, and mice were anesthetized with ether and sacrificed with the same anesthetic. Pieces of pancreas were processed for transmission electron microscopy. Semithin sections were observed by light microscopy and, after positive identification by transmission electron microscopy, lymphatics were followed with long series of consecutive sections to define their distribution. Lymphatics were detected in the pancreas of all the animals both in the inter and the intralobular sites. Closer relations with the exocrine parenchyma (ducts and acini) were observed in guinea pig pancreas. Remarkably, interesting relationships between lymphatics and endocrine tissue were observed in all the animals. Overall, however, the lymphatic network of rat pancreas was less develop and preferentially associated with blood vessels. The distribution of the pancreatic lymphatic network appears consistent with an active role in pancreatic pathology.

Animals↗
PubMed1995

Fine structure of healthy human gingival mast cells and their immunological characterization.

Despite the great number of studies on mast cell population, at the present time few are the studies regarding the structural aspects of mast cells in human gingiva. In order to identify and characterize gingival mast cells, specimens of healthy human gingival tissue have been studied. Subsequently, in order to test mast cell capability of express TNF-alfa, samples of healthy gingiva with antibody anti-TNF-alfa have been incubated. The results showed that in human gingiva mast cells are numerous and ubiquitarious. These cells exhibit several morphological types of cytoplasmic granules with characteristic subgranular content, varying in shape and density. This allows to divide gingival mast cells into two different subpopulations: either cells containing granules with compact coiled scrolls and/or particles and cells showing granules with scrolls and thin parallel bands. The two ultrastructural aspects observed seem to be correlated to the McT (mast cells containing tryptase) and McTC (mast cells containing tryptase and chymase) described in international literature, differing for ultrastructural aspect, biochemical content and response to secretagogue substances. The positivity of the reaction for TNF-alfa seems indeed to confirm that gingival mast cells are able to secrete sensible amounts of TNF-alfa.

Adolescent↗
PubMed1991

[In vitro and in vivo biocompatibility tests of some endodontic cements].

The major goal of endodontic therapy has been achieved by condensing filling materials into the root canal. It is not uncommon to find excess material in the periapical tissue. It therefore becomes obligatory to use filling materials that have acceptable biocompatibility. The purpose of this investigation was to obtain a "toxicity profile" of some root canal materials and to compare our observations to study results found in literature. Gutta-percha and five endodontic filling cements were tested in vivo and in vitro. The in vivo biocompatibility involved the placement of the test material in 10 mm teflon tubes with an outer diameter of 1,3 mm which were then implanted subcutaneously into rats. The implants were left in situ for periods of 30 and 90 days. The hemolysis test was used for in vitro evaluations. The histological examination showed cellular responses of different intensity and extent. In some cases severe infiltration of inflammatory cells and areas with necrostis were observed. As a result, the root canal materials evaluated showed slight, moderate, and severe reactions, therefore, a different pattern in tissue response.

Animals↗
PubMed1989

Behaviour of adenylic and pyridinic compounds in gingival tissue after a short-term exposure to air.

Biochemical variations of adenine and pyridine compounds in human gingival grafts during the period between excision and implantation have been studied. These groups of compounds are considered as "indicators" of the metabolic and energetic status of the living cells. Adenylic compounds such as ATP, ADP and AMP are involved in numerous metabolic processes as "modulators" of allosteric enzymes. NAD+ and NADP+ are involved in the carbohydrate metabolism as co-factors of many reactions of oxydoreduction. The exposure to air of the gingival tissue induces modifications in the energy state of the cells as well as in the ox-reox system. No variation is detectable in the intermediates of the pyridine compounds cycle.

Adenine Nucleotides↗
PubMed1988

Non specific acid esterase activity in human periapical inflammatory cells.

The fine structural localization of non specific acid alpha-naphthyl acetate esterase activity (ANAE) in human periapical inflammatory cells was studied in sections of paraffin embedded tissue of 20 human periapical lesions (granulomas). Examination of specimens incubated with ANAE resulted in ANAE+ cells interpreted as T-lymphocytes, monocytes, macrophages, giant cells and plasma cells. ANAE- lymphocytes were interpreted as B cells. Our findings do not seem to confirm the presence among human periapical inflammatory cells of NK (natural killer) cells. T-lymphocytes were the most represented cellular type. The macrophages with ANAE+ reaction were numerous in all specimens observed and the variation in staining intensity could reflect a varying stage of activation. These findings allow conclusions about the role of T-lymphocyte mediated immune reaction in the pathogenesis of periapical lesions. The possibility that the activated T-lymphocytes within the periapical lesions may have a critical role in establishing and maintaining granuloma formation is also discussed.

Carboxylesterase↗
PubMed1986

Effect of the novel synthetic protease inhibitor furoyl saccharin on elastase-induced emphysema in rabbits and hamsters.

Furoyl saccharin, a novel heterocyclic acylating agent which has been previously found to possess a potent inhibitory capacity in vitro for elastase and other serine proteases, has been investigated in vivo in two acute animal models of emphysema. In hamsters, intratracheal (i.tr.) administration of 0.1 mg porcine pancreatic elastase resulted seven days later, in a 42% increase of the mean linear intercept (Lm). Addition of 0.3 mg to 0.3 mg furoyl saccharin to elastase exhibited a partial, not dose-related, but statistically significant inhibition of the increase of LM. Addition of 1 mg furoyl saccharin (equivalent to a dose of 12.5 mg/kg) completely abolished the increase in Lm. In the rabbit i.tr. instillation of 3.7 mg porcine pancreatic elastase induced within seven days, a 48% increase of the Lm, a 27% decrease of the internal surface area (ISA) of the lungs and a 33% decrease of the ISA corrected to an arbitrary total lung volume of 70 ml (ISA70). Furoyl saccharin given i.tr. 15 min prior to elastase at the doses 3, 10 and 20 mg prevented significantly in a dose-related manner, the changes in Lm, ISA and ISA70. The highest furoyl saccharin dose (equivalent to a dose of 10.8 mg/kg) completely protected against the emphysematous lesion. Additionally furoyl saccharin (20 mg i.tr.) prevented in the rabbit model the depletion in lung insoluble elastin and the increase in salt soluble collagen induced by the elastase administration. These results show that furoyl saccharin also in vivo has a marked antielastase activity.

Animals↗
PubMed1984

Pulmonary changes induced in rabbits by long-term exposure to n-hexane.

New Zealand male rabbits were exposed in an inhalation chamber to 3,000 ppm of n-hexane 8 h/day, 5 days/week for 24 weeks, resulting in a total of 120 exposures. After a further 120 days in clean air, morphologic examination of lungs by light and transmission electron microscopy (TEM) revealed three important exposure-related lesions. These consisted of air space enlargement centered on respiratory bronchioles and alveolar ducts (centriacinar emphysema), scattered foci of pulmonary fibrosis, and papillary tumors of non-ciliated bronchiolar epithelial cells. At TEM examination these tumors were rather homogeneous and were found to consist of cells showing both small and large electron dense ovoid granules in their cytoplasmic matrix, a feature that has been described for Clara cells. The implications of these findings are discussed.

Animals↗
PubMed1984

[Root caries].

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Aged↗