[Mobbing: ten-year evaluation experience in a University Hospital]. / Mobbing: esperienza decennale di valutazione in un Policlinico Universitario.

OBJECTIVES: Bullying is a manifestation of occupational stress and can therefore be considered as a real "organizational pathology." Include the activities of the surgery dedicated to Mobbing, Unit of Occupational Medicine Sant'Andrea Hospital, which began operations in June 2001. METHODS: In over ten years of operation (July 2012), the sample, consisting of 50.7% for men and 49.3% women, is heterogeneous in age. The schooling of the sample is medium-high as more than 82% have higher education level. The business sector is the service sector accounted for most (84%) than in industry (9%) and agriculture (2%). RESULTS: Of the 1545 patients seen, 1320 completed the diagnostic path, while 225 have stopped. 814 users have been certified for compatibility bullying (63% of cases) with a net reduction of the awards from 2007 onwards. CONCLUSIONS: Considerations are expressed about the possible intervention strategies: the presence of dedicated experts at the counters of listening and professionals as the trusted advisor, to which workers in distress can call on for advice and guidance on how to defend itself from, in accordance with the implemented for years at the Ministry of Health, the establishment of such figures as the manager rehability that in other European countries, are scheduled for some time in work organization.

Prolonged fasting identifies heat shock protein 10 as a Sirtuin 3 substrate: elucidating a new mechanism linking mitochondrial protein acetylation to fatty acid oxidation enzyme folding and function.

Although Sirtuin 3 (SIRT3), a mitochondrially enriched deacetylase and activator of fat oxidation, is down-regulated in response to high fat feeding, the rate of fatty acid oxidation and mitochondrial protein acetylation are invariably enhanced in this dietary milieu. These paradoxical data implicate that additional acetylation modification-dependent levels of regulation may be operational under nutrient excess conditions. Because the heat shock protein (Hsp) Hsp10-Hsp60 chaperone complex mediates folding of the fatty acid oxidation enzyme medium-chain acyl-CoA dehydrogenase, we tested whether acetylation-dependent mitochondrial protein folding contributes to this regulatory discrepancy. We demonstrate that Hsp10 is a functional SIRT3 substrate and that, in response to prolonged fasting, SIRT3 levels modulate mitochondrial protein folding. Acetyl mutagenesis of Hsp10 lysine 56 alters Hsp10-Hsp60 binding, conformation, and protein folding. Consistent with Hsp10-Hsp60 regulation of fatty acid oxidation enzyme integrity, medium-chain acyl-CoA dehydrogenase activity and fat oxidation are elevated by Hsp10 acetylation. These data identify acetyl modification of Hsp10 as a nutrient-sensing regulatory node controlling mitochondrial protein folding and metabolic function.

Polyamine catabolism in carcinogenesis: potential targets for chemotherapy and chemoprevention.

Polyamines, including spermine, spermidine, and the precursor diamine, putrescine, are naturally occurring polycationic alkylamines that are required for eukaryotic cell growth, differentiation, and survival. This absolute requirement for polyamines and the need to maintain intracellular levels within specific ranges require a highly regulated metabolic pathway primed for rapid changes in response to cellular growth signals, environmental changes, and stress. Although the polyamine metabolic pathway is strictly regulated in normal cells, dysregulation of polyamine metabolism is a frequent event in cancer. Recent studies suggest that the polyamine catabolic pathway may be involved in the etiology of some epithelial cancers. The catabolism of spermine to spermidine utilizes either the one-step enzymatic reaction of spermine oxidase (SMO) or the two-step process of spermidine/spermine N (1)-acetyltransferase (SSAT) coupled with the peroxisomal enzyme N (1)-acetylpolyamine oxidase. Both catabolic pathways produce hydrogen peroxide and a reactive aldehyde that are capable of damaging DNA and other critical cellular components. The catabolic pathway also depletes the intracellular concentrations of spermidine and spermine, which are free radical scavengers. Consequently, the polyamine catabolic pathway in general and specifically SMO and SSAT provide exciting new targets for chemoprevention and/or chemotherapy.

[The inclusion of the subject safety in the school curriculum;checking the validity of the hypothesis in schools in three provinces]. / L'inserimento della materia sicurezza nei programmi scolastici: verifica della validità dell'ipotesi nelle scuole di tre province.

According to Italian Legislative Decree no. 81/2008, workplace safety will have to be introduced in school and university curricula. The main objectives of this study of the Italian Ministry of Labour were to verify knowledge about workplace safety among primary and secondary school students and evaluate the effectiveness of a training course in improving students' knowledge. Three provinces with an above average workforce/injuries ratio (with respect to the national average) were identified. An evaluation questionnaire was administered to students in the three provinces. Students then attended training courses about workplace safety and were then administered the same questionnaire. Primary school students improved by an average of 35.5%, middle school students by 33.3%, high school students by 18.6%. Results suggests that the training intervention was effective.

Contrast-enhanced magnetic resonance imaging of 102 nodules in cirrhosis: correlation with histological findings on explanted livers.

PURPOSE: To analyze Gd-EOB-DTPA-enhanced magnetic resonance (MR) findings of nodules (low-grade dysplastic nodules-LGDNs; high-grade dysplastic nodules-HGDN, and hepatocellular carcinoma-HCC), histologically identified on cirrhotic, explanted livers. METHODS: IRB approval was obtained for this study. Thirty-four patients underwent Gd-EOB-DTPA-enhanced MR examinations (1.5T system), that included 20-min delayed hepatobiliary (HB) phase imaging, before undergoing orthotopic liver transplantation (OLT; mean time MR-OLT: 2.7 months). A total of 102 hepatic nodules were identified and analyzed at histopathological examination, and classified as LGDN, HGDN, and HCC. Two radiologists by consensus performed a quantitative (enhancement ratios, ERs) and a qualitative analyses of signal intensities of identified nodules on vascular dynamic phases (30-35 s after injection-arterial phase; 180-190 s after injection late phase) and on HB phases. Correlation between nodules MR patterns and histological classification was analyzed by means of dedicated statistical software. RESULTS: No differences were appreciable among ERs of HGDN and HCCs on HB phase (P > 0.001). Lesions' enhancement on vascular dynamic and on HB phases significantly correlated to histological classification of nodules (P < 0.0001). Nodular hyperintensity on arterial phase and hypointensity on late phase were highly predictive for HCC (PPV 100%), with a moderate sensitivity (72.5%). Nodular hypointensity on HB phase was detected on 39/40 HCCs (sensitivity 97.5%) and in 21/30 HGDNs, whereas no LGDN showed it. CONCLUSIONS: Hyperenhancement on arterial phase and hypointensity on late phase are the most specific clues for the diagnosis of HCC. Hypointensity on HB phase shows a PPV of 100% in suggesting nodular premalignancy/malignancy, independently from nodular dynamic vascular enhancement.

Mitochondrial oxidative stress induced by Ca2+ and monoamines: different behaviour of liver and brain mitochondria in undergoing permeability transition.

Mitochondrial permeability transition (MPT) is correlated with the opening of a nonspecific pore, the so-called transition pore, that triggers bidirectional traffic of inorganic solutes and metabolites across the mitochondrial membrane. This phenomenon is caused by supraphysiological Ca(2+) concentrations and by other compounds leading to oxidative stress, while cyclosporin A, ADP, bongkrekic acid, antioxidant agents and naturally occurring polyamines strongly inhibit it. The effects of polyamines, including the diamine agmatine, have been widely studied in several types of mitochondria. The effects of monoamines on MPT have to date, been less well-studied, even if they are involved in a variety of neurological and neuroendocrine processes. This study shows that in rat liver mitochondria (RLM), monoamines such as tyramine, serotonin and dopamine amplify the swelling induced by calcium, and increase the oxidation of thiol groups and the production of hydrogen peroxide, effects that are counteracted by the above-mentioned inhibitors. In rat brain mitochondria (RBM), the monoamines do not amplify calcium-induced swelling, even if they demonstrate increases in the extent of oxidation of thiol groups and hydrogen peroxide production. In these mitochondria, the antioxidants are not at all or scarcely effective in suppressing mitochondrial swelling. In conclusion, we hypothesize that different mechanisms induce the MPT in the two different types of mitochondria evaluated. Calcium and monoamines induce oxidative stress in RLM, which in turn appears to induce and amplify MPT. This process is not apparent in RBM, where MPT seems resistant to oxidative stress.

Further characterization of agmatine binding to mitochondrial membranes: involvement of imidazoline I2 receptor.

Agmatine, a divalent diamine with two positive charges at physiological pH, is transported into the matrix of liver mitochondria by an energy-dependent mechanism, the driving force of which is the electrical membrane potential. Its binding to mitochondrial membranes is studied by applying a thermodynamic treatment of ligand-receptor interactions on the analyses of Scatchard and Hill. The presence of two mono-coordinated binding sites S(1) and S(2), with a negative influence of S(2) on S(1), has been demonstrated. The calculated binding energy is characteristic for weak interactions. S(1) exhibits a lower binding capacity and higher binding affinity both of about two orders of magnitude than S(2). Experiments with idazoxan, a ligand of the mitochondrial imidazoline receptor I(2), demonstrate that S(1) site is localized on this receptor while S(2) is localized on the transport system. S(1) would act as a sensor of exogenous agmatine concentration, thus modulating the transport of the amine by its binding to S(2).

Polyamine catabolism: target for antiproliferative therapies in animals and stress tolerance strategies in plants.

Metabolism of polyamines spermidine and spermine, and their diamine precursor, putrescine, has been a target for antineoplastic therapy since these naturally occurring alkyl amines were found essential for normal mammalian cell growth. Intracellular polyamine concentrations are maintained at a cell type-specific set point through the coordinated and highly regulated interplay between biosynthesis, transport, and catabolism. A correlation between regulation of cell proliferation and polyamine metabolism is described. In particular, polyamine catabolism involves copper-containing amine oxidases and FAD-dependent polyamine oxidases. Several studies showed an important role of these enzymes in several developmental and disease-related processes in both animals and plants through a control on polyamine homeostasis in response to normal cellular signals, drug treatment, environmental and/or cellular stressors. The production of toxic aldehydes and reactive oxygen species, H(2)O(2) in particular, by these oxidases using extracellular and intracellular polyamines as substrates, suggests a mechanism by which the oxidases can be exploited as antineoplastic drug targets. This minireview summarizes recent advances on the physiological roles of polyamine catabolism in animals and plants in an attempt to highlight differences and similarities that may contribute to determine in detail the underlined mechanisms involved. This information could be useful in evaluating the possibility of this metabolic pathway as a target for new antiproliferative therapies in animals and stress tolerance strategies in plants.

Effect of peroxides on spermine transport in rat brain and liver mitochondria.

The polyamine spermine is transported into the matrix of various types of mitochondria by a specific uniporter system identified as a protein channel. This mechanism is regulated by the membrane potential; other regulatory effectors are unknown. This study analyzes the transport of spermine in the presence of peroxides in both isolated rat liver and brain mitochondria, in order to evaluate the involvement of the redox state in this mechanism, and to compare its effect in both types of mitochondria. In liver mitochondria peroxides are able to inhibit spermine transport. This effect is indicative of redox regulation by the transporter, probably due to the presence of critical thiol groups along the transport pathway, or in close association with it, with different accessibility for the peroxides and performing different functions. In brain mitochondria, peroxides have several effects, supporting the hypothesis of a different regulation of spermine transport. The fact that peroxovanadate can inhibit tyrosine phosphatases in brain mitochondria suggests that mitochondrial spermine transport is regulated by tyrosine phosphorylation in this organ. In this regard, the evaluation of spermine transport in the presence of Src inhibitors suggests the involvement of Src family kinases in this process. It is possible that phosphorylation sites for Src kinases are present in the channel pathway and have an inhibitory effect on spermine transport under regulation by Src kinases. The results of this study suggest that the activity of the spermine transporter probably depends on the redox and/or tyrosine phosphorylation state of mitochondria, and that its regulation may be different in distinct organs.

Chronic exposure to agmatine results in the selection of agmatine-resistant hepatoma cells.

During our study of the cytostatic effect of agmatine, we were able to isolate an agmatine resistant clone from a parental hepatoma cell line, HTC. These cells, called Agres, had slower growth rate than the parental cells when cultured in normal medium. The modification in polyamine content induced by agmatine was much lower in these cells and ornithine decarboxylase, S-adenosylmethionine decarboxylase and spermidine/spermine acetyltransferase activities were much less affected. By investigating the mechanism responsible for these modifications, it was shown that agmatine and polyamines were not taken up by Agres cells. Their resistance to the antiproliferative effects of agmatine may thus arise from a lack of the polyamine transport system. Moreover, Agres cells were able to take up both glutamic acid and arginine at a rate significantly higher than that detected for HTC cells, most likely to provide components for compensatory increase of PA synthesis. These results emphasize the importance of polyamine transport for cell growth.

Preliminary kinetic characterization of a copper amine oxidase from rat liver mitochondria matrix.

Kinetic measurements of a novel copper-dependent amine oxidase, purified from rat liver mitochondria matrix, were carried out using various substrates in a large pH (5.6-10.2) and ionic strength range (5-200 mM), in order to study the docking of substrates to the enzyme and, as a consequence, to verify the physicochemical characteristics of the active site. Relatively small changes of V(max) values (approx. 2.5-folds) over the substrates tested, suggest that the rate determining step of the catalysis is only slightly affected by amine chemical structure. In contrast, the strong change of K(M) and k(c)/K(M) values (approx. two orders of magnitude) indicates electrostatic control of the docking process, since the changes of K(M) and k(c)/K(M) values appear due to the presence of positively charged groups in the substrate molecules. These results suggest the presence in the enzyme active site of two negatively charged amino acid residues which seem to interact with positively charged groups of the substrate molecules. Analogies and differences with bovine serum amine oxidase are also described.

Complete response for advanced liver cancer during sorafenib therapy: case report.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fifth most common neoplasia in the world. In the past, treatment of advanced HCC with conventional antineoplastic drugs did not result in satisfactory outcomes: recently, in this patient population the oral multikinase inhibitor sorafenib has been able to induce a statistically significant improvement of overall survival. Similarly to other anti-angiogenic drugs employed in other tumour types, also sorafenib seldom induces the dimensional tumour shrinking usually observed with conventional cytotoxic drugs: data gathered from studies carried out with sorafenib and other competitors under development do not report any complete response in HCV-induced HCC. CASE PRESENTATION: An 84-year old man with a long-lasting history of chronic HCV hepatitis was referred to our Institution for an ultrasonography investigation of a focal hepatic lesion. To better characterize the liver disease and clearly define the diagnosis of the focal hepatic lesion, the patient was hospitalized in our department. Laboratory and instrumental investigations confirmed the clinical picture of HCV-related liver cirrhosis and identified a hepatic lesion of about 6 cm featuring infiltrating HCC with thrombosis of the portal trunk. Due to the advanced stage of the disease, therapy with sorafenib 400 mg bid was started. Right from one month after the treatment was started, a reduction of alpha-fetoprotein level was observed which, by the third month, turned down within the normal limits. In addition the CT scan showed 50% reduction of the neoplastic lesion along with canalization of the portal trunk. At the sixth month the normalization of the alpha-fetoprotein level at the lower limit of normality was confirmed and the MRI showed complete disappearance of the neoplasia. In addition a reduction of a metallo-proteinase serum level was observed. At the twelfth month a further MRI confirmed complete response had been maintained. At present the patient is in a follow-up program to evaluate the duration of the complete response. CONCLUSIONS: This case is worth mentioning since, to the best of our knowledge, it represents the first evidence of complete response to sorafenib in an elderly patient with advanced HCV-related HCC.

Hepatocellular nodules in liver cirrhosis: contrast-enhanced MR.

Nowadays, the diagnosis of hepatocellular carcinoma (HCC) is increasingly demanded to imaging techniques. Anyway, imaging cirrhotic patients still remains a challenging issue, since pre-neoplastic hepatocellular lesions, as dysplastic nodules (DNs), may frequently mimic small neoplasms. Differently from other imaging modalities, magnetic resonance (MR) can give an accurate evaluation of both intracellular and vascular changes occurring during the carcinogenetic pathway from dysplasia to full malignancy. Both DNs and HCC may in fact show a large variety of signal intensities, strictly reflecting nodules' characteristics, such as lesion architecture, grading, stromal components, as well as intracellular contents. In these last years, the introduction of dedicated contrast media has increased MR diagnostic efficacy, permitting to explore both vascular as well as the pathological changes occurring in the biliary and reticuloendothelial systems during the carcinogenetic process. MR performed with tissue specific contrast agents (hepatobiliary and reticulo-endothelial) may thus give an insight on this "gray area", in whom significant histological changes are already present without an evident nodule arterial supply. This peculiar MR prerogative permits to give predictive information about the evolution trend in a cirrhotic parenchyma and to identify patients at high risk for developing carcinoma who would benefit from well-timed treatments.

Multidetector CT in the evaluation of retroperitoneal fat tissue infiltration in ductal adenocarcinoma of the pancreatic head: correlation with histopathological findings.

BACKGROUND: Neoplastic infiltration of the retroportal fat tissue is a critical parameter in tumor staging and in surgical planning because it frequently represents a site of persistence and recurrence of disease. METHOD: We evaluated 64 patients affected by ductal adenocarcinoma of the pancreatic head/uncinate process, submitted to curative surgery. Suspicion of infiltration (micro or macroinfiltration) of the retroportal margin arose at MDCT in cases of obliteration, irregularity, or abnormal density of the fatty layer localized between the medial surface of the pancreatic head/uncinate process and the mesenteric artery. RESULTS: CT suggested the infiltration of the retroportal tissue in 27 cases (10 microinfiltration, 17 macroinfiltration). At histopathology, the presence of infiltration was confirmed in 21/27 (78%) cases. In all CT cases of microinfiltration, the retroperitoneal resection margin was not infiltrated, while all cases (6) with infiltration of the retroperitoneal margin were macroinfiltrated at CT. The sensitivity of CT was 80%, specificity of 84% with an overall diagnostic accuracy of 82%. CONCLUSION: MDCT is accurate in the assessment of the neoplastic infiltration of the retroportal fat tissue.

Glycyrrhetinic acid as inhibitor or amplifier of permeability transition in rat heart mitochondria.

Glycyrrhetinic acid (GE), a hydrolysis product of glycyrrhizic acid, one of the main constituents of licorice root, is able, depending on its concentration, to prevent or to induce the mitochondrial permeability transition (MPT) (a phenomenon related to oxidative stress) in rat heart mitochondria (RHM). In RHM, below a threshold concentration of 7.5 microM, GE prevents oxidative stress and MPT induced by supraphysiological Ca2+ concentrations. Above this concentration, GE induces oxidative stress by interacting with a Fe-S centre of Complex I, thus producing ROS, and amplifies the opening of the transition pore, once again induced by Ca2+. GE also inhibits Ca2+ transport in RHM, thereby preventing the oxidative stress induced by the cation. However, the reduced amount of Ca2+ transported in the matrix is sufficient to predispose adenine nucleotide translocase for pore opening. Comparisons between observed results and the effects of GE in rat liver mitochondria (RLM), in which the drug induces only MPT without exhibiting any protective effect, confirm that it interacts in a different way with RHM, suggesting tissue specificity for its action. The concentration dependence of the opposite effects of GE, in RHM but not RLM, is most probably due to the existence of a different, more complex, pathway by means of which GE reaches its target. It follows that high GE concentrations are necessary to stimulate the oxidative stress capable of inducing MPT, because of the above effect, which prevents the interaction of low concentrations of GE with the Fe-S centre. The reported results also explain the mechanism of apoptosis induction by GE in cardiomyocytes.

Novel copper amine oxidase activity from rat liver mitochondria matrix.

Copper containing amine oxidases (Cu-AO) represent a heterogeneous class of enzymes classified as EC 1.4.3.6. The present study reports preliminary results on the presence of a novel amine oxidase activity in rat liver mitochondria lysates. Such enzymatic activity was found in the soluble mitochondrial fraction, obtained by simple osmotic shock. The mitochondrial amine oxidase was isolated by affinity chromatography on a newly synthesised spermine-Sepharose. SDS-PAGE showed a single band at about 60kDa. Upon chromatographic purification, the enzymatic activity was very labile. The crude enzyme activity was tested by spectrophotometric measurements, determining hydrogen peroxide production following oxidative deamination of different substrates, such as polyamines (spermine, spermidine, putrescine and cadaverine) and monoamines (dopamine and benzylamine). The activity, observed on polyamines and not on monoamines, was inhibited by semicarbazide and azide, but not by pargyline, clorgyline and l-deprenil. Enzyme specificity was tested on several diamines characterized by different carbon atom chain length in the range 2-6 carbon atoms. The highest activity was found with 1,2-diamino-ethane and the highest affinity with 1,5-diamino-pentane. The above reported results suggest the presence of a novel copper-dependent amine oxidase in liver mitochondria matrix.

HCC diagnosis with liver-specific MRI--close to histopathology.

Thanks to the sensible and continuous improvements achieved, magnetic resonance imaging (MRI) can nowadays be considered the most accurate modality to image the liver. Moreover, the technique is the only one able to provide at the same time information about intracellular and vascular changes occurring in parenchymas. For these reasons, MRI plays a major role in the surveillance and follow-up of patients with cirrhosis. If a baseline MR study investigates the progressive alteration of lesion architecture, grading, stromal component, as well as intracellular content of fat, glycogen, or metal ions, thus leading to a frequent confident diagnosis of lesion nature, a dynamic study provides additional information about lesion vascular enhancement, which may represent the only clue for the differential diagnosis between premalignant and malignant lesions. In addition, the introduction of hepatobiliary contrast agents has further implemented the diagnostic confidence of the technique, permitting to explore the so-called grey area in which significant histological changes are already present without an evident arterial supply of the nodule. Although in the evaluation of liver pathologies MRI is mainly applied in the study of cirrhosis, the technique also plays a fundamental role in the assessment of other primitive liver malignancies, such as fibrolamellar carcinoma or cholangiocarcinoma. In these cases in particular, MRI is required to pose a differential diagnosis with other liver malignancies (such as metastases), and, once the nature of the neoplasm is assessed, to give an accurate locoregional staging.

Successful Transplant of a Nonagenarian Liver Graft With Fully Replaced Right Hepatic Artery Reconstruction.

Organ shortage and increasing donor age in liver transplant are stimulating transplant centers to accept otherwise discarded grafts due to donor age or vascular abnormalities; nevertheless, the use of nonagenarian donor grafts is uncommon because advanced age is associated with a higher risk of ischemic-type biliary lesions and worse long-term graft survival. We herein report the case of a 90-year-old donor with fully replaced right hepatic artery. After back-table vascular assessment, the donor right hepatic artery was anastomosed end-to-end with the gastroduodenal artery with 2 polypropylene 8/0 running sutures. Even if the back-table reconstruction of a replaced right hepatic artery is not associated with an enhanced risk of posttransplant vascular complications, vascular abnormalities might discourage the use of otherwise acceptable elderly grafts. The present case underscores that elderly liver grafts should not be discarded per se even in the presence of vascular variants.

Anti-apoptotic effect of Mao-B inhibitor PF9601N [N-(2-propynyl)-2-(5-benzyloxy-indolyl) methylamine] is mediated by p53 pathway inhibition in MPP+-treated SH-SY5Y human dopaminergic cells.

PF9601N [N-(2-propynyl) 2-(5-benzyloxyindol) methylamine] is a non-amphetamine type MAO-B inhibitor that has shown neuroprotective properties in vivo using different experimental models of Parkinson's disease. The mechanisms underlying its neuroprotective effects are poorly understood, but appear to be independent of MAO-B inhibition. We have studied its neuroprotective properties using the human SH-SY5Y dopaminergic cell line exposed to 1-methyl-4-phenylpyridinium (MPP(+)), a cellular model of Parkinson's disease. PF9601N pre-treatment significantly reduced MPP(+)-induced cell death and decreased the activation of one of the main executioner caspases, caspase-3. MPP(+) induced stabilization of transcription factor p53, which led to increased levels of this transcription factor, its nuclear translocation and transactivation of p53 response elements. PF9601N prevented this increase, thus reducing its transcriptional activity. Additional results showed that p53 may mediate its pro-apoptotic actions through caspase-2 under our experimental conditions. PUMA-alpha may also contribute to the p53-induced cell death. Since PF9601N significantly reduced MPP(+)-induced caspase-2 activity and PUMA-alpha levels, this reduction may lead to increased cell survival. Thus, PF9601N is a novel molecule with an apparently novel mechanism of action which has a promising potential as a therapeutic agent in the treatment of neurodegenerative diseases.