Publications by authors named "Mauro Melato"

Mesothelioma is a malignant tumor mainly correlated to occupational asbestos exposure. Rare reports describe its occurrence also in animals, mainly linked to asbestos in the environment. Asbestos exposure is demonstrated by the appearance of characteristic histological hallmarks: asbestos containing ferruginous bodies that are iron-based structures forming around fibers and also other dust particles.

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It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin, if conveniently differentiated. Nowadays, however, a study on their efficiency in osseous regeneration does not exist in scientific literature and this very task is the real aim of the present experimentation. Five different defects of 6 mm in diameter and 2 mm in depth were created in the calvaria of 8 white New Zealand rabbits.

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Carbon nanotubes (CNTs) are promising products in industry and medicine, but there are several human health concerns since their fibrous structure resembles asbestos. The presence of transition metals, mainly iron, in the fibres seems also implicated in the pathogenetic mechanisms. To unravel the role of iron at mesothelial level, we compared the chemical changes induced in MeT-5A cells by the exposure to asbestos (crocidolite) or CNTs at different content of iron impurities (raw-SWCNTs, purified- and highly purified-SWCNTs).

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Background: Germline mutations of the oncosuppressor gene breast cancer 1-associated protein 1 (BAP1) were recently related to an autosomal-dominant tumor predisposition syndrome (BAP1-TPDS), characterized by uveal melanoma, malignant mesothelioma (MM), cutaneous melanoma, and other malignancies. The demonstration that BAP1 mutations are strongly associated with MM has provided a real breakthrough in the study of genetic predisposition in MM, that may explain why only a fraction of asbestos-exposed individuals go on to develop MM.

Materials And Methods: To evaluate the possible role of BAP1 mutations in the epidemiology of sporadic MM, and their relationship with asbestos exposure, we determined the prevalence of germline BAP1 mutations by the Sanger method in a group of 29 asbestos-exposed patients, 21 of which were diagnosed with MM.

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Asbestos bodies are the histological hallmarks of asbestos exposure. Both conventional and advanced techniques are used to evaluate abundance and composition in histological samples. We previously reported the possibility of using synchrotron X-ray fluorescence microscopy (XFM) for analyzing the chemical composition of asbestos bodies directly in lung tissue samples.

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Human exposure to asbestos can cause a wide variety of lung diseases that are still a current major health concern, even if asbestos has been banned in many countries. It has been shown in many studies that asbestos fibers, ingested by alveolar macrophages, disrupt lung iron homeostasis by sequestering iron. Calcium can also be deposited on the fibers.

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Environmental and occupational inhalants may induce a large number of pulmonary diseases, with asbestos exposure being the most risky. The mechanisms are clearly related to chemical composition and physical and surface properties of materials. A combination of X-ray fluorescence (μXRF) and Fourier Transform InfraRed (μFTIR) microscopy was used to chemically characterize and compare asbestos bodies versus environmental particulates (anthracosis) in lung tissues from asbestos exposed and control patients.

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Background: Defects in the cell-cycle surveillance mechanism, called the spindle checkpoint, might contribute to the chromosomal instability observed in human cancers, including oral squamous cell carcinoma. MAD2 and BUBR1 are key components of the spindle checkpoint, whose role in oral carcinogenesis and clinical relevance still need to be elucidated.

Materials And Methods: We analyzed the expression of MAD2 in 49 cases of oral squamous cell carcinoma by immunohistochemistry and compared the findings with clinicopathological parameters, proliferative activity, BUBR1 expression and DNA ploidy.

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Asbestos is a potent carcinogen associated with malignant mesothelioma and lung cancer but its carcinogenic mechanisms are still poorly understood. Asbestos toxicity is ascribed to its particular physico-chemical characteristics, and one of them is the presence of and ability to adsorb iron, which may cause an alteration of iron homeostasis in the tissue. This observational study reports a combination of advanced synchrotron-based X-ray imaging and micro-spectroscopic methods that provide correlative morphological and chemical information for shedding light on iron mobilization features during asbestos permanence in lung tissue.

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In this study, we have performed a morphological analysis of crocidolite fibres interaction with mesothelial cells (MET5A) by combining conventional electron microscopy with atomic force (AFM) and scanning near-field optical microscopy (SNOM). After 6-h exposure at a crocidolite dose of 5 μg cm(-2), 90% of MET5A cells interact with fibres that under these conditions have a low cytotoxic effect. SEM images point out that fibres can be either engulfed by the cells that lose their typical morphology or they can accumulate over or partially inside the cells, which preserve their typical spread morphology.

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Ferruginous bodies (FB) are polymorphic structures whose formation is macrophage dependent, and are composed of a core, which may consist of an asbestos fiber coated with proteins, among which ferritin is the main component. Within ferritin, the ferric and ferrous ions are coordinated as ferrihydrite, which is the main iron (Fe) storage compound. However, when ferritin accumulates in some tissues following Fe overload it also contains magnetite along with ferrihydrite, which endows it with magnetic properties.

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Gastrointestinal stromal tumors (GISTs) are the most common primary mesenchymal tumors of the gastrointestinal tract, and most of them harbor KIT or platelet-derived growth factor receptor alpha (PDGFRA) gain-of-function mutations. Proper diagnostic assessment of GISTs has become very important since the availability of the molecular-targeted therapy with imatinib mesylate. Histopathology remains the gold standard in GIST diagnosis, and immunohistochemistry plays the major confirmatory role.

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Background: Occupational or environmental exposure to asbestos fibres is associated with pleural and parenchymal lung diseases. A histopathologic hallmark of exposure to asbestos is the presence in lung parenchyma of the so-called asbestos bodies. They are the final product of biomineralization processes resulting in deposition of endogenous iron and organic matter (mainly proteins) around the inhaled asbestos fibres.

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Background: Defects in the mitotic spindle checkpoint have been proposed to contribute to the chromosomal instability observed in human cancers, including oral squamous cell carcinoma (OSCC). BUBR1 is a key component of the spindle checkpoint, whose role in oral carcinogenesis still needs to be clarified.

Methods: We have analyzed the expression of BUBR1 in 49 cases of OSCC by immunohistochemistry and compared the findings with clinicopathologic parameters, proliferative activity, and DNA ploidy.

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We present a case of primary pericardial mesothelioma occurring in an asbestos-exposed 67-year-old man who underwent four aortocoronary bypass grafting seven years prior to the onset of the mesothelioma. Primary pericardial mesothelioma is a rare tumor whose association with asbestos is more infrequent than that of the much more common pleural form. Factors other than asbestos that may play a role include genetic predisposition, immune impairment, infections, radiation, dietary factors, and recurrent serosal inflammation.

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Sebaceous neoplasms, including carcinoma, can exceptionally arise in extracutaneous sites. We present the third known case of carcinoma with sebaceous differentiation in the uterine cervix. Histologic and immunohistochemical features suggested a metaplastic process within an otherwise usual squamous cell carcinoma.

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Background: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a recently identified death factor that acts as a potent apoptosis inducer in ameloblastomas.

Materials And Methods: The expression of TRAIL and its receptors (TRAIL-R), and the location of apoptotic cells were evaluated in 15 cases of ameloblastoma using immunohistochemistry and an in situ DNA nick-end labeling method. The proliferative activity of ameloblastomas was analyzed by determining the Ki-67 labeling index.

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To assess the presence of SV40 in malignant mesothelioma tissue, 19 formalin-fixed paraffin-embedded pleural cancer samples of patients from a hyperendemic area of northeastern Italy were analyzed retrospectively. A total of 48 other tissues from the malignant mesothelioma subjects were investigated. The SV40 load was determined by real-time quantitative PCR.

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The role of asbestos bodies (and associated proteinacious coating) in asbestos associated diseases is not well understood. Currently employed methods of isolation of these bodies employ harsh chemicals that lead to destruction of their proteinacious coating. In this work a method was developed that enabled the purification of whole, integral, unmodified asbestos bodies (AB) by exploiting their magnetic properties.

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The case of a 64-year-old man presenting dysuria and haematuria is described. The cause of these symptoms was related to a splenomegaly compressing the left kidney and renal pelvis. A splenectomy was performed.

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Ovarian-type mucinous tumors may occasionally occur in the retroperitoneum, pancreas, and liver exclusively or almost exclusively in women. In men, only few cases of such neoplasms arising within or around the testis have been reported. We describe a unique case of an ovarian-type mucinous cystadenoma occurring in the peritoneal cavity of a 65-year-old male patient with secondary adrenocortical insufficiency and hypogonadism.

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Starting from the observation that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2L protein is expressed in both malignant and inflammatory cells in some highly vascularized soft tissue sarcomas, the angiogenic potential of TRAIL was investigated in a series of in vitro assays. Recombinant soluble TRAIL induced endothelial cell migration and vessel tube formation to a degree comparable to vascular endothelial growth factor (VEGF), one of the best-characterized angiogenic factors. However, the proangiogenic activity of TRAIL was not mediated by endogenous expression of VEGF.

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The aim of this work was to characterize p53 and PCNA expression in primary tumours and lymph node metastases of oral/oropharynx carcinomas by flow cytometry and to evaluate the possibility of a relationship between these parameters in primary tumours and locoregional metastasis, clinical-histopathological parameters and survival time. A group of 28 patients was retrospectively selected: 13 with metastasis and 15 without metastasis. The following clinical and histopathological parameters were considered: degree of keratinization, Broders' grading of histological differentiation, invasive cell grading, thickness and tumour size.

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