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P Braidotti

Publications and source records attributed to P Braidotti.

At least 19 recordsLinked to original sources
PubMed2006

Direct visualization of neo-vessel formation following peripheral injection of bone marrow derived CD34+ cells in experimental myocardial damage.

The definitive fate of peripherally injected PKH26 labelled bone marrow mononuclear cells expressing the CD34+ antigen following experimental myocardial cryodamage in rats (n=10) has been examined by direct visualization on photoconverted light and electron microscopy images. One week after the injection in each rat of about 150,000 CD34+ cells early stage PKH26+ vascular structures were localized in the infarcted areas, suggesting that a potential benefit of this therapeutic approach consists in the regeneration of the vasculature.

Animals↗
PubMed2006

Assessment of selective homing and contribution to vessel formation of cryopreserved peripherally injected bone marrow mononuclear cells following experimental myocardial damage.

In view of a potential clinical use we aimed this study to assess the selective homing to the injured myocardium and the definitive fate of peripherally injected labeled and previously cryopreserved Bone Marrow Mononuclear cells (BMMNCs). The myocardial damage (cryoinjury) was produced in 59 rats (45 treated, 14 controls). From 51 donor rats 4.4 x 10(9) BMMNCs were isolated and cryopreserved (slow-cooling protocols); the number of CD34+ and the viability of pooled cells was assessed by flow-cytometry analysis before and after cryopreservation and simulated delivery through a 23G needle. Seven days after injury, BMMNCs were thawed, labeled with PKH26 dye and peripherally injected (20 x 10(6) cells in 500 microl) in recipient rats. Two weeks after experimental injury, the heart, lungs, liver, kidneys, spleen and thymus were harvested to track transplanted cells. Except a small amount in the spleen, PKH26+ cells were found only in the infarcted myocardium of the treated animals. Typical vascular structures CD34+ were found in the infarcted areas of all animals; treated rats showed a significantly higher number of these structures if compared with untreated. Morphological ultra-structural examination of infarcted areas confirmed in treated rats the presence of early-stage PKH26+ vascular structures derived from injected BMMNCs. The estimated mean CD34+ cells loss due to the cryopreservation procedure and to the system of delivery was 0.24% and 0.1%, respectively, confirming the feasibility of the procedure. This study supports the possible therapeutic use of cryopreserved peripherally injecetd BMMNCs as a source of CD34+ independent vascular structures following myocardial damage.

Animals↗
PubMed2005

Liver histology of an afibrinogenemic patient with the Bbeta-L353R mutation showing no evidence of hepatic endoplasmic reticulum storage disease (ERSD); comparative study in COS-1 cells of the intracellular processing of the Bbeta-L353R fibrinogen vs. the ERSD-associated gamma-G284R mutant.

BACKGROUND: Type I fibrinogen deficiencies (hypofibrinogenemia and afibrinogenemia) are rare congenital disorders characterized by low or unmeasurable plasma fibrinogen antigen levels. Their genetic bases are represented by mutations within the three fibrinogen genes. Among the 11 reported missense mutations, a few have been characterized by expression studies and found to have an impaired fibrinogen assembly and/or secretion. Histopathological analyses were previously reported in two hypofibrinogenemic cases with discernible hepatic disease, revealing that both underlying mutations (gamma-Gly284Arg and gamma-Arg375Trp) were associated with hepatic fibrinogen endoplasmic reticulum storage disease (ERSD). OBJECTIVE: The objective of this study was to investigate the liver histology in an afibrinogenemic patient, homozygous for the Bbeta-Leu353Arg mutation, and to study the intracellular processing of the mutant protein. PATIENTS AND METHODS: Liver histology was evaluated by light microscopy, electron microscopy and immunocytochemistry. Intracellular processing of mutant fibrinogen was analyzed by pulse-chase labeling and immunoprecipitation experiments. Messenger RNA levels were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The histopathological characterization of the liver showed no signs of fibrinogen accumulation, a difference from the previously reported findings in two hypofibrinogenemic kindreds with ERSD. To evaluate whether the Bbeta-Leu353Arg mutation and the ERSD-associated gamma-Gly284Arg mutation affected intracellular fibrinogen trafficking differently, both mutant proteins were expressed in COS-1 cells. Bbeta-Leu353Arg led to a more severe secretion defect, but no differences that could explain phenotype-genotype correlation were found in the intracellular processing. Endoglycosidase-H analysis demonstrated a secretion block before translocation to the Golgi medial stacks. Real-time RT-PCR studies showed normal levels of the Bbeta mRNA in the patient's liver. CONCLUSIONS: The results confirm that Bbeta-Leu353Arg is associated with impaired fibrinogen secretion, but not with hepatic ERSD.

Adolescent↗
PubMed2005

Medullary and papillary carcinoma of the thyroid gland occurring as a collision tumour: report of three cases with molecular analysis and review of the literature.

We report the simultaneous occurrence of medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC), presenting as spatially distinct and well-defined tumour components, in three cases. In the first patient, histology, immunohistochemistry and electron microscopy demonstrated an MTC in the one nodule and PTC in two additional lesions. Non-neoplastic thyroid parenchyma separated the three nodules. Metastasis from PTC was diagnosed in a regional lymph node. Genetic analysis of both tumour components showed a distinctive mutational pattern: in the MTC a Cys634Arg substitution in exon 11 of the RET gene and in the two PTC foci a Val600Glu substitution in exon 15 of the BRAF gene. The other two patients are members of a large multigenerational family affected with familial MTC due to a germline mutation of the RET gene (Ala891Ser). Both patients harboured, besides medullary cancer and C-cell hyperplasia, distinct foci of papillary thyroid cancer, which was positive for Val600Glu BRAF mutation. Review of the literature disclosed 18 similar lesions reported and allowed the identification of different patterns of clinical presentation and biological behaviour. So far, the pathogenesis of these peculiar cases of thyroid malignancy has been completely unknown, but an underlying common genetic drive has been hypothesised. This is the first report in which two mutations, in the RET and BRAF genes, have been identified in three cases of MTC/PTC collision tumour, thus documenting the different genetic origin of these two coexisting carcinomas.

Adult↗
PubMed2004

DMBT1 expression is down-regulated in breast cancer.

BACKGROUND: We studied the expression of DMBT1 (deleted in malignant brain tumor 1), a putative tumor suppressor gene, in normal, proliferative, and malignant breast epithelium and its possible relation to cell cycle. METHODS: Sections from 17 benign lesions and 55 carcinomas were immunostained with anti DMBT1 antibody (DMBTh12) and sections from 36 samples, were double-stained also with anti MCM5, one of the 6 pre-replicative complex proteins with cell proliferation-licensing functions. DMBT1 gene expression at mRNA level was assessed by RT-PCR in frozen tissues samples from 39 patients. RESULTS: Normal glands and hyperplastic epithelium in benign lesions displayed a luminal polarized DMBTh12 immunoreactivity. Normal and hyperplastic epithelium adjacent to carcinomas showed a loss of polarization, with immunostaining present in basal and perinuclear cytoplasmic compartments. DMBT1 protein expression was down-regulated in the cancerous lesions compared to the normal and/or hyperplastic epithelium adjacent to carcinomas (3/55 positive carcinomas versus 33/42 positive normal/hyperplastic epithelia; p = 0.0001). In 72% of cases RT-PCR confirmed immunohistochemical results. Most of normal and hyperplastic mammary cells positive with DMBTh12 were also MCM5-positive. CONCLUSIONS: The redistribution and up-regulation of DMBT1 in normal and hyperplastic tissues flanking malignant tumours and its down-regulation in carcinomas suggests a potential role in breast cancer. Moreover, the concomitant expression of DMTB1 and MCM5 suggests its possible association with the cell-cycle regulation.

Agglutinins↗
PubMed2003

Clinical histopathology and ultrastructural analysis of myocardium following microwave energy ablation.

OBJECTIVE: Due to weaknesses of conventional modes for treating atrial fibrillation (AF), surgical energy ablation methods and tools to cure AF have been under rapid development. One of these methods, microwave energy, is beginning to be applied clinically. The purpose of this study was to examine histology and ultrastructure of lesions produced by microwave energy in the myocardium. METHODS: Fifteen consecutive patients underwent surgical microwave energy ablation (Microwave Ablation System with FLEX 4 probe, AFx Inc., Fremont, CA) concomitant to a valve procedure. Epicardial ablation was carried out on the beating normothermic heart prior to performing the valve procedure. Two tissue specimens (1cm(2)) were obtained from each patient; one from the lesion site (right appendage) and the other from an adjacent, non-ablated site, which was used as control. Tissue samples were fixed and stained as appropriate for histological and ultrastructural analysis. RESULTS: All ablated samples revealed observable microscopic alteration, including loss of nuclei, foci of coagulative necrosis or induced irregular bands of contraction. Ultrastructurally, ablated cells demonstrated architectural disarray, loss of contractile filaments, mitochondrial swelling and focal interruption of plasma membrane. CONCLUSIONS: Histologic appearance of lesions created by epicardial microwave energy ablation was consistent over tissue samples, although acute findings demonstrated differences from cryoablation. In most of the cases, lesions were transmural, as was demonstrated by loss of cellular viability throughout the depth of tissue specimens.

Atrial Fibrillation↗
PubMed2003

Bread wheat gliadin cytotoxicity: a new three-dimensional cell model.

BACKGROUND: In an attempt to clarify the role of gliadin toxicity in the pathogenesis of gluten intolerance (celiac disease), previous in vitro studies have been based on two-dimensional human cell cultures. However, the specific morphological and biochemical properties of in vivo tissue are better maintained in three-dimensional cell cultures (multicellular spheroids, MCS). The aim of this study was to develop a three-dimensional in vitro model to investigate the effects of gliadin on epithelial cells and broaden our understanding of the early tissue damage occurring in celiac disease. METHODS: The three-dimensionally growing Lovo cell line was exposed to increasing concentrations of peptic-tryptic-digested bread wheat gliadin (from 125 to 1000 microg/mL) for 7 days in order to evaluate cell viability (colony-forming assay), and at the standard concentration of 500 microg/mL for 7 days in order to evaluate MCS diameters, volumes and cell morphology using light and electron microscopy. RESULTS: In comparison with the controls, the cell viability of the gliadin-treated MCS was significantly reduced (20-80%), but there was no difference in size. Various degrees of cell damage (autophagic vacuoles and intra-cytoplasmic lipid-like droplets) were detected by both light and electron microscopy. CONCLUSION: This is the first study investigating the effects of gliadin on MCS. Lovo MCS seem to be responsive to gliadin exposure, thus confirming previous results obtained using two-dimensional cell cultures. The data suggest that three-dimensional cell cultures may be useful in broadening our understanding of some of the early effects of gliadin peptides on epithelial cells.

Adenocarcinoma↗
PubMed2001

Primary intrathoracic meningioma: histopathological, immunohistochemical and ultrastructural study of two cases.

Meningiomas are common, usually benign slow-growing neoplasms of the central nervous system thought to arise from meningocytes capping arachnoid villi. Primary ectopic meningiomas are exceedingly rare extracranial and extraspinal tumors of controversial origin; they are usually limited to the head and neck region or to the paravertebral soft tissues. Only one mediastinal ectopic meningioma and few pulmonary ectopic meningiomas have been described in the literature until now. Because of their rarity and their intriguing pathogenesis, we report here a second case of primary mediastinal meningioma and an additional case of primary pulmonary meningioma. Their possible origin and differential diagnosis are discussed.

Biomarkers, Tumor↗
PubMed2001

Endothelial targeting with C1-inhibitor reduces complement activation in vitro and during ex vivo reperfusion of pig liver.

Tissue damage during cold storage and reperfusion remains a major obstacle to wider use of transplantation. Vascular endothelial cells and complement activation are thought to be involved in the inflammatory reactions following reperfusion, so endothelial targeting of complement inhibitors is of great interest. Using an in vitro model of human umbilical vein endothelial cells (HUVEC) cold storage and an animal model of ex vivo liver reperfusion after cold ischaemia, we assessed the effect of C1-INH on cell functions and liver damage. We found that in vitro C1-INH bound to HUVEC in a manner depending on the duration of cold storage. Cell-bound C1-INH was functionally active since retained the ability to inhibit exogenous C1s. To assess the ability of cell-bound C1-INH to prevent complement activation during organ reperfusion, we added C1-INH to the preservation solution in an animal model of extracorporeal liver reperfusion. Ex vivo liver reperfusion after 8 h of cold ischaemia resulted in plasma C3 activation and reduction of total serum haemolytic activity, and at tissue level deposition of C3 associated with variable level of inflammatory cell infiltration and tissue damage. These findings were reduced when livers were stored in preservation solution containing C1-INH. Immunohistochemical analysis of C1-INH-treated livers showed immunoreactivity localized on the sinusoidal pole of the liver trabeculae, linked to sinusoidal endothelium, so it is likely that the protective effect was due to C1-INH retained by the livers. These results suggest that adding C1-INH to the preservation solution may be useful to reduce complement activation and tissue injury during the reperfusion of an ischaemic liver.

Animals↗
PubMed2001

Usefulness of histological examination for the diagnosis of onychomycosis.

BACKGROUND: [corrected] Direct microscopy and culture tests currently used in the diagnosis of nail mycosis can yield false-negative results, and confirmation of the pathogenic agent, especially in non-dermatophyte infections, is often a lengthy process. OBJECTIVE: The aim of this study was to investigate the usefulness of the histological examination of nail clipping samples in supplementing the standard microscopic and culture techniques for the diagnosis of onychomycosis. PATIENTS AND METHODS: One hundred and seventy-two subjects affected by nail alterations suggestive of onychomycosis were evaluated. Nail specimens were studied with 3 different techniques: direct microscopic examination of a 40% KOH clarified preparation, fungal culture and histological examination. Patients positive for fungal infection were re-evaluated with the same techniques after treatment with oral terbinafine, fluconazole or itraconazole and topical application of bifonazole or ciclopirox for 2 months. RESULTS: Direct microscopy was positive in 102 (59.3%) nail specimens. The culture test was positive in 90 cases (52.9%), showing a dermatophyte in 45, a yeast in 23 and a mould in 22 samples. The histological examination was positive in 94 (54.6%) samples. In 4 cases, it was the only investigation confirming the clinical diagnosis of nail mycosis. In most of the cases, the morphological aspect of the hyphae and/or spores suggested also to which group of pathogens (dermatophytes, yeasts or moulds) the mycetes observed in the histological sections could be ascribed. The concurrent presence of a dermatophyte and a mould was evidenced in a few specimens. The control histological examination at the end of the treatment showed negative results or residual non-vital hyphae and/or spores. CONCLUSIONS: Results of the present study indicate that the histological examination of nail clipping specimens is a relatively inexpensive, rapid and easily performed procedure. It is useful to confirm or refute the results of routine microscopy and culture tests. Moreover, nail histopathological observation may help in ascribing a pathogenic role of non-dermatophyte isolates and evaluating the effectiveness of antifungal treatment.

Adolescent↗
PubMed2001

Post-translational processing of surfactant protein-C proprotein: targeting motifs in the NH(2)-terminal flanking domain are cleaved in late compartments.

Rat surfactant protein (SP)-C is a 3.7-kD hydrophobic lung-specific protein generated from proteolytic processing of a 21-kD propeptide (SP-C(21)). We have demonstrated that initial post-translational processing of SP-C(21) involves two cleavages of the COOH-terminus (Beers and colleagues, J. Biol. Chem. 1994;269:20,318--20,328). The goal of the current study was to define processing and function of the NH(2)-terminal flanking domain. Epitope-specific antisera directed against spatially distinct regions of the NH(2) terminus, NPROSP-C(2-9) (epitope = D(2)-L(9)) and NPROSP-C(11-23) (= E(11)-Q(23)) were produced. By Western blotting, both antisera identified SP-C(21) in microsomes. A 6-kD form (SP-C(6)), enriched in lamellar bodies (LBs), was detected only by NPROSP-C(11-23) and not extractable with NaCO(3) treatment. Immunogold staining of ultrathin lung sections with NPROSP-C(11-23) identified proSP-C in both multivesicular bodies (mvb) and LBs whereas NPROSP-C(2-9) labeled only mvb. (35)S-pulse chase analysis demonstrated synthesis of SP-C(21) and three intermediate forms (SP-C(16), SP-C(7), and SP-C(6)). Complete processing involved four separate cleavages with a precursor- product relationship between the low molecular weight forms SP-C(7) and SP-C(6). Fluorescence microscopy of A549 cells expressing fusion proteins of enhanced green fluorescent protein (EGFP) and proSP-C NH(2)-terminal deletion mutants showed targeting of EGFP/SP-C(1-194) and EGFP/SP-C(10-194) to early endosomal antigen-1-negative, CD-63-positive cytoplasmic vesicles whereas EGFP/SP-C(19-194), EGFP/SP-C(Delta 10-18), and EGFP/SP-C(24-194) were restricted to the endoplasmic reticulum (ER). We conclude that synthetic processing includes a previously unrecognized cleavage of the proximal NH(2) terminus (M(1)-L(9)), which occurs after removal of COOH-flanking domains (H(59)-I(194)) but before packaging in LBs, and that the region M(10)-T(18) is required for targeting of proSP-C to post-ER vesicular compartments in the biosynthetic pathway.

Amino Acid Sequence↗
PubMed2001

Surfactant protein A expression in human normal and neoplastic breast epithelium.

We studied the presence of surfactant protein A (Sp-A) immunoreactivity and messenger RNA in 62 normal and abnormal breast samples. Sections were immunostained with polyclonal anti-Sp-A antibody. The association between Sp-A immunoreactivity and histologic grade of 32 invasive ductal carcinomas was assessed by 3 pathologists who scored the intensity of Sp-A immunoreactivity times the percentage of tumor immunostained; individual scores were averaged, and the final scores were correlated with tumor grade, proliferative index, and expression of estrogen and progesterone receptors. Strong Sp-A immunoreactivity was present at the luminal surface of ductal epithelial cells in normal breast samples and in benign lesions; carcinomas displayed variable immunoreactivity, inversely proportional to the degree of differentiation. Sp-A messenger RNA was detected by reverse transcriptase-polymerase chain reaction in 3 of 3 normal breast samples and 9 of 9 carcinomas. The significance of Sp-A expression in breast epithelium requires further study; possibly it has a role in native host defense or epithelial differentiation.

Breast↗
PubMed2001

Unusual clear cell variant of epithelioid mesothelioma.

Clear cell mesothelioma is an extremely rare neoplasm of the pleura, which can easily be mistaken for a metastasis of clear cell carcinoma to the pleura. We report here the histochemical, immunohistochemical, and ultrastructural aspects of a new case of clear cell pleural mesothelioma in a 52-year-old man with no known asbestos exposure. He was admitted to the hospital for recurrent pleural effusion, which was negative for neoplastic cells at the cytologic examination. A partial decortication of the right pleura was performed. The morphologic, immunohistochemical, and ultrastructural features reported for this case are consistent with the diagnosis of clear cell mesothelioma. The differential diagnosis and immunohistochemical features in comparison with other clear cell neoplasms are discussed.

Biomarkers, Tumor↗
PubMed2000

Peripheral papillary tumor of type-II pneumocytes: a rare neoplasm of undetermined malignant potential.

Peripheral papillary adenomas of the lung are uncommon neoplasms (only ten cases have been described so far in the English literature) composed predominantly of type-II pneumocytes and generally considered benign. We describe here two additional cases of this lung tumor. In both cases histological examination revealed an encapsulated papillary neoplasm with invasion of the capsule and, in one case, invasion of the adjacent alveoli and visceral pleura too. The proliferative index (Ki67) was less than 2% and the epithelial cells were positive for cytokeratins, surfactant apoproteins (SP), and nuclear thyroid transcription factor-1 (TTF- 1). Ultrastructurally, the epithelial cells showed the characteristic surface microvilli and cytoplasmic lamellar inclusions of type-II cells. Review of the literature has revealed two other cases of peripheral papillary adenoma of type-II pneumocytes with infiltrative features. Thus, we propose replacing the term peripheral papillary adenoma with peripheral papillary tumor of undetermined malignant potential.

Adenoma↗
PubMed2000

Tensile experiments and SEM fractography on bovine subchondral bone.

Subchondral bone undecalcified samples, extracted from bovine femoral heads, are subjected to a direct tensile load. The Young's modulus of each sample is determined from repeated tests within the elastic limit. In a last test, the tensile load is increased up to the specimen failure, determining the ultimate tensile strength. The investigation is performed on both dry and wet specimens. The measured Young's modulus for dry samples is 10.3+/-2.5GPa, while that of wet samples is 3.5+/-1.2GPa. The ultimate tensile strengths are 36+/-10 and 30+/-7.5MPa for dry and wet specimens, respectively. SEM micrographs of failure surfaces show characteristic lamellar bone structures, with lamellae composed of calcified collagen fibers. Rudimentary osteon-like structures are also observed. Failure surfaces of wet samples show a marked fiber pull-out, while delamination predominates in dry samples. The obtained results are interpreted on the basis of the deformation mechanisms typical of fiber-reinforced laminated composite materials.

Animals↗
PubMed2000

[Surfactant protein and thyroid transcription factor 1 in pleuro-pulmonary neoplasia. Immunohistochemical study].

Aim of this work was to investigate the ability of the antibodies against Surfactant proteins (SP) and Thyroid transcription factor 1 (TTF-1) to distinguish primary neoplasms of the lung from metastatic carcinomas to the lung and pleural mesotheliomas. We evaluated the immunohistochemical expression of the antibodies anti SP-A, SP-B, pro SP-C, SP-D, and TTF-1 in a series of 56 primary lung carcinomas, 9 metastatic carcinomas to the lung, 5 pleural mesotheliomas and 8 non-pulmonary carcinomas. Among primary lung neoplasms, only adenocarcinomas immunostained for all SP (specificity = 1; total sensitivity = 0.52). TTF-1 had an excellent specificity (= 1), but a weak sensitivity (= 0.34) in recognizing primary lung carcinomas. TTF-1 was present in lung adenocarcinomas which were negative for SPs; however it failed to distinguish the subtypes. Pleural mesotheliomas, pulmonary metastases and non-pulmonary carcinomas were not immunoreactive for SP-A, SP-B, SP-D, and TTF-1. Pro SP-C was positive also in the adenocarcinomas of the large bowel and in their pulmonary and nodal metastases. These results demonstrate that the combined use of antibodies anti SP-A, SP-B and TTF-1 is the best association in distinguishing primary lung carcinomas from metastatic carcinomas to the lung and pleural mesotheliomas.

Adenocarcinoma↗
PubMed1999

Alzheimer's beta-amyloid peptides can activate the early components of complement classical pathway in a C1q-independent manner.

beta-Amyloid (beta-A) accumulates in the brain of patients with Alzheimer's disease (AD) and is presumably involved in the pathogenesis of this disease, on account of its neurotoxicity and complement-activating ability. Although assembly of beta-A in particular aggregates seems to be crucial, soluble non-fibrillar beta-A may also be involved. Non-fibrillar beta-A does not bind C1q, so we investigated alternative mechanisms of beta-A-dependent complement activation in vitro. On incubation with normal human plasma, non-fibrillar beta-A 1-42, and truncated peptide 1-28, induced dose-dependent activation of C1s and C4, sparing C3, as assessed by densitometric analysis of immunostained membrane after SDS-PAGE and Western blotting. The mechanism of C4 activation was not dependent on C1q, because non-fibrillar beta-A can still activate C1s and C4 in plasma genetically deficient in C1q (C1qd). In Factor XII-deficient plasma (F.XIId) the amount of cleaved C4 was about 5-10% less that in C1qd and in normal EDTA plasma; the reconstitution of F.XIId plasma with physiologic concentrations of F.XII resulted in an increased (8-15%) beta-A-dependent cleavage of C4. Thus our results indicate that the C1q-independent activation of C1 and C4 can be partially mediated by the activation products of contact system. Since the activation of contact system and of C4 leads to generation of several humoral inflammatory peptides, non-fibrillar beta-A might play a role in initiating the early inflammatory reactions leading to a multistep cascade contributing to neuronal and clinical dysfunction of AD brain.

Alzheimer Disease↗