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.

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.

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.

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.

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.

[Biocompatibility and physico-mechanical properties of the new Venezia root canal sealer. In vivo and in vitro test according international standards]. / Biocompatibilità e caratteristiche meccanico-fisiche del nuovo cemento endodontico Venezia. Prove in vivo e in vitro secondo norme ISO.

At the moment, in most countries, there are laws in force which impose to the manufacturers well regulated testing in order to investigate and guarantee an acceptable biocompatibility of medical devices before their commercialization. Many international laboratories are committed to the definition of investigation methodologies and to the evaluation of biocompatibility in order to obtain research standards, capable to provide reproducible and comparable objective quantitative data. In every country, technical committees were put together for a standardization of methodological procedures, followed by European and international technical boards which proposed and codified methodologies and investigation approaches. UNI-EN-ISO laws contain all the results and constitute a reference point for any consideration on or evaluation of the biocompatibility of a medical device. Based on these laws, we evaluated the biocompatibility and determined the physical-mechanical characteristics of the new Venezia (Cabon S.p.A.) endodontic ZOE sealer. The Subcutaneous Implant Technique according Safavi et al. (in vivo test, ISO 10993: 1-6 Biological evaluation of medical and dental materials and devices) and Autian test of Emolysis on Rabbit Erythrocytes (in vitro test) allowed us to evaluate a good biocompatibility of the new product. Furthermore, its Setting and Working time, its radiopacity, Solubility and its Flow value completely satisfy the requirements of international standards (ISO/DIS 6876 Dental root Canal Sealing Materials). We can finally deduce that Venezia fulfil the ideal functional properties of an endodontic cements.

In vitro and in vivo effects of chloramine T on rat serum elastase inhibitor.

Recent studies have shown that oxidizing agents may block the elastase inhibitory activity of alpha 1-antiproteinase in humans and some animal species. It has been postulated that this protein plays a critical role in modulating the activity of the neutral proteinase, i.e. elastase, in the lung; its inactivation has been implicated in the destruction of lung tissue seen in emphysema. In this work, we have studied the inactivation in vitro of rat serum elastase inhibitor by chloramine T (CT) and whether the in vivo use of the same oxidizing agent in the development of a functional model of alpha 1-antiproteinase deficiency in the rat is feasible. Although serum alpha 1-antiproteinase is readily inactivated in vitro by CT, it was observed, in vivo, that serum elastase inhibitory capacity was reduced to about 28-35% of initial levels 1-3 h after CT injection, and returned to control values within 9 h. Therefore, the in vivo study demonstrated that in the rat a functional model of alpha 1-antiproteinase deficiency cannot be achieved by inactivation of the protein molecule with CT. The relatively short half-life (1.45 h) of the serum elastase inhibitor found in normal rats is consistent with a rapid synthesis of the protein molecule, which might contribute to the fast recovery of the elastase inhibitory capacity observed in experimental animals after CT administration.

[Pulmonary damage in the rabbit caused by porcine pancreatic elastase and leukocyte lysate: unusual microscopic aspects]. / Il danno polmonare nel coniglio da elastasi pancreatica porcina e lisato leucocitario : particolari aspetti microscopici.

Intratracheal injection of rabbit whole leukocyte homogenate induced emphysema-like lesions in rabbits. The lesions were produced only by preparations having elastinolytic activity. The pathological aspects appeared similar to those induced by the administration of porcine pancreatic elastase. The pulmonary changes, resembling several of the anatomic appearances of panacinar human emphysema, may be a suitable experimental model for studying histogenesis of panacinar human emphysema. Numerous abnormal fenestrations were present in air spaces walls and were a constant feature in opposition to that has been reported in elastase-treated hamsters. For the presence of a prominent dilatation of the periarterial lymphatic network, this experimental model might be used also for studying the ultrastructural features of pulmonary lymphatic vessels.

Atypical cilia in rabbit bronchial epithelial cells induced by elastase: an ultrastructural study.

Ultrastructural study of the bronchial epithelium of elastase-treated rabbits revealed the presence of luminal atypical cilia resembling the pathological cilia seen in the tracheobronchial epithelium in animal models of human lung cancer. It is suggested that the results may contribute to knowledge of the mechanisms whereby compound cilia are produced.

Respiratory tract lesions induced in rabbits by short-term exposure to N-hexane.

New Zealand rabbits were exposed in inhalation chambers to 3,000 ppm of n-hexane 8h/d for 8 d, and the acute respiratory effects were studied by light and electron microscopy. Animals intoxicated showed morphological changes in the lung parenchyma characterized by centriacinar emphysema and scattered micro haemorrhages. Lung damage was most severe at the transition zone from terminal bronchiole to alveolar ducts. This centriacinar lesion consisted to degenerative and necrotic phenomena in bronchiolar epithelium with cellular desquamation, increased number of macrophages within proximal alveoli of alveolar ducts, increased number and size of lamellar bodies in alveolar type II cells, changes in the vascular endothelium. Focal subpleural atelectasis, alveolar and interstitial oedema were also found. The segmental distribution of the pulmonary lesions were confirmed by transmission electron microscopy.

Salivary mercury levels in healthy donors with and without amalgam fillings.

Dental amalgam (AMG) is the most diffused dental filling material. Since it is constituted for at least 40-45% of Hg, many questions have raised about its safe use. Hg particles from dental amalgam dissolve in saliva and, being ingested, they reach the blood stream through the intestinal mucosa. It has been demonstrated that amalgam fillings continuously release Hg vapour and that there is detectable Hg in expired and inspired air of amalgam owners. It is not yet fully accepted that AMG fillings represent the principal source of Hg for man and the aim of this study was to evaluate if the mercury level in saliva: 1) was higher within people bearing dental amalgam restorations than in people with no restorations; 2) was different between males or females; 3) increased in relation to the surface of amalgam restorations. The results showed a correlation between number of fillings and salivary Hg, between amalgam surface and salivary Hg. The Authors could finally assert that AMG fillings represented the principal source of salivary Hg in the subjects studied.

Etiopathogenesis, prevention and therapeutic strategies of snoring pathologies.

The sleep of adults and childrens is often disturbed from obstructive respiratory desorders evidenced from snoring. Scientific literature agrees in considering that as a dangerous pathology called roncopathy. Statistics show that about 50% of adult population over 50 yrs snores (exspecially males) and some of that has a dangerous period of prolonged and frequent obstructive sleep apneas. Results of polisomnographic tests show that 4% of total population suffer of apneas extremely severe and dangerous for life. Roncopathy is often associated to a lot of troubles: pulmonary, gastroenterologic, endocrinologic, of behaviour and especially cardiovascular and neurologic and this could explain the motif of high nocturnal percentage of myocardial infarction, ictus and sudden death. In this work we evidence the anatomical and functional etiology of snoring and sleep apneas and expose the surgical and medical therapeutic options up to day available.

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.

[A rare case of continuous type spleno-gonadal fusion]. / A propos d'un cas rare de fusion spléno-gonadique de type continue.

The authors present a case of continuous spleno-testicular fusion in a three year old child and emphasize the rarity of this condition, on the basis of an examination of the literature. The pathogenic mechanisms and clinical characteristics of this condition are studied in the light of the reported cases, and are discussed.

Cytokeratin 20-expressing M cells in tonsils take up particulate antigen. A site for the delivery of vaccines against oral pathogens?

Quantitative and qualitative control of oral bacterial flora is a major issue in oral pathology and in the prophylaxis against cavities. Recent findings suggest that it is possible to induce local immune responses delivering antigens on palatine tonsils. M cells play an important role in the start of the immune response. These cells are located in the epithelia overlaying mucosal lymphoid follicles and are responsible for the uptake of particulate antigens. The identification of reliable markers for M cell is therefore extremely important. Since it has been reported that tonsillar immunization leads to the secretion of high levels of specific salivary antibody, we undertook a study to identify a marker for tonsillar M cells in order to plan strategies of oral immunization against oral pathogens. We studied cytokeratin 20 expression in rabbit tonsils by immunofluorescence and confocal microscopy. Cytokeratin 20 immunoreactive cells were observed in all samples examined. These cells were identified as M cells as they co-expressed vimentin, a well-known marker of rabbit M cells, and they actively uptook particulate material. It is therefore possible to hypothesize the use of tonsil M cells as a possible site for antigen delivery of particle-based vaccines against oral pathogens.

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.

Response of lung enzyme activities in rabbits following short-term exposure to n-hexane: correlation between morphological and biochemical changes.

The activity of lactate dehydrogenase, beta-glucuronidase, glucose-6-phosphate dehydrogenase, acid and alkaline phosphatase was studied in lung homogenate from New Zealand rabbits exposed to 3000 p.p.m. of n-hexane 8 h per day for 8 days of filtered air. In hydrocarbon-treated animals all enzymes examined, except alkaline phosphatase, were markedly increased. The biochemical changes correlated well with the morphological changes and the results of cytological evaluation of bronchopulmonary lavage. It is suggested that high values in lung lysosomal enzymes from treated rabbits reflect the acute inflammation whilst the increase in lung glucose-6-phosphate dehydrogenase may depend upon reparative process subsequent to n-hexane-induced lung damage.