1,714 research outputs found
Cobalt, chromium and molybdenum ions kinetics in the human body: data gained from a total hip replacement with massive third body wear of the head and neuropathy by cobalt intoxication.
6openopenPazzaglia, U; Apostoli, P; Congiu, T; Catalani, S; Marchese, M; Zarattini, G.Pazzaglia, Ugo; Apostoli, Pietro; Congiu, T; Catalani, S; Marchese, M; Zarattini, Guid
Monitoraggio ambientale e biologico dell’esposizione ad idrocarburi mono-aromatici ed a metil tert-butil etere in un gruppo di lavoratori addetti all’erogazione di carburanti
Lo studio è stato condotto per valutare
gli indicatori biologici di esposizione a vapori di benzina
in lavoratori addetti all’erogazione di carburante tramite
un approccio combinato di monitoraggio ambientale
e biologico. L’esposizione personale a benzene, toluene,
etilbenzene e xilene (BTEX) e l’escrezione urinaria di BTEX,
metil tert-butil etere (MTBE-U), degli acidi trans,transmuconico
(t,t-MA) ed S-fenilmercapturico (S-PMA) e della
cotinina sono stati valutati con tecniche cromatografiche
accoppiate alla spettrometria di massa. I livelli di MTBE-U
erano influenzati dalla sola esposizione professionale a vapori
di benzina, mentre quelli di B-U ed S-PMA dipendevano
da abitudine tabagica ed esposizione professionale
Maxillary fungus ball: zinc-oxide endodontic materials as a risk factor
open7openNICOLAI, Piero; MENSI, Magda; Marsili, F.; Piccioni, M.; SALGARELLO, Stefano Alessandro; GILBERTI, Maria Enrica; Apostoli, P.Nicolai, Piero; Mensi, Magda; Marsili, F.; Piccioni, M.; Salgarello, Stefano Alessandro; Gilberti, Maria Enrica; Apostoli, P
Role of inorganic nitrate and nitrite in driving nitric oxide-cGMP-mediated inhibition of platelet aggregation in vitro and in vivo
This is the peer reviewed version of the article, which has been published in final form at [doi: 10.1111/jth.12711. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.Nitric oxide (NO) is a critical negative regulator of platelets that is implicated in the pathology of thrombotic diseases. Platelets generate NO, but the presence and functional significance of NO synthase (NOS) in platelets is unclear. Inorganic nitrate/nitrite is increasingly being recognized as a source of bioactive NO, although its role in modulating platelets during health and vascular dysfunction is incompletely understood.
METHODS:
We investigated the functional significance and upstream sources of NO-cGMP signaling events in platelets by using established methods for assessing in vitro and in vivo platelet aggregation, and assessed the bioconversion of inorganic nitrate to nitrite during deficiency of endothelial NOS (eNOS).
RESULTS:
The phosphodiesterase 5 (PDE5) inhibitor sildenafil inhibited human platelet aggregation in vitro. This inhibitory effect was abolished by a guanylyl cyclase inhibitor and NO scavengers, but unaffected by NOS inhibition. Inorganic nitrite drove cGMP-mediated inhibition of human platelet aggregation in vitro and nitrate inhibited platelet function in eNOS(-/-) mice in vivo in a model of thromboembolic radiolabeled platelet aggregation associated with an enhanced plasma nitrite concentration as compared with wild-type mice.
CONCLUSIONS:
Platelets generate transient, endogenous cGMP signals downstream of NO that are primarily independent of NOS and may be enhanced by inhibition of PDE5. Furthermore, nitrite can generate transient NO-cGMP signals in platelets. The absence of eNOS leads to enhanced plasma nitrite levels following nitrate administration in vivo, which negatively impacts on platelet function. Our data suggest that inorganic nitrate exerts an antiplatelet effect during eNOS deficiency, and, potentially, that dietary nitrate may reduce platelet hyperactivity during endothelial dysfunction.British Pharmacological Society Integrative Pharmacology Fund Pump Priming Grant
Effects of airborne pollutants on mitochondrial DNA Methylation
Background: Mitochondria have small mitochondrial DNA (mtDNA) molecules independent from the nuclear DNA, a separate epigenetic machinery that generates mtDNA methylation, and are primary sources of oxidative-stress generation in response to exogenous environments. However, no study has yet investigated whether mitochondrial DNA methylation is sensitive to pro-oxidant environmental exposures. Methods: We sampled 40 male participants (20 high-, 20 low-exposure) from each of three studies on airborne pollutants, including investigations of steel workers exposed to metal-rich particulate matter (measured as PM1) in Brescia, Italy (Study 1); gas-station attendants exposed to air benzene in Milan, Italy (Study 2); and truck drivers exposed to traffic-derived Elemental Carbon (EC) in Beijing, China (Study 3). We have measured DNA methylation from buffy coats of the participants. We measured methylation by bisulfite-Pyrosequencing in three mtDNA regions, i.e., the transfer RNA phenylalanine (MT-TF), 12S ribosomal RNA (MT-RNR1) gene and “D-loop” control region. All analyses were adjusted for age and smoking. Results: In Study 1, participants with high metal-rich PM1 exposure showed higher MT-TF and MT-RNR1 methylation than low-exposed controls (difference = 1.41, P = 0.002); MT-TF and MT-RNR1 methylation was significantly associated with PM1 exposure (beta = 1.35, P = 0.025); and MT-RNR1 methylation was positively correlated with mtDNA copy number (r = 0.36; P = 0.02). D-loop methylation was not associated with PM1 exposure. We found no effects on mtDNA methylation from air benzene (Study 2) and traffic-derived EC exposure (Study 3). Conclusions: Mitochondrial MT-TF and MT-RNR1 DNA methylation was associated with metal-rich PM1 exposure and mtDNA copy number. Our results suggest that locus-specific mtDNA methylation is correlated to selected exposures and mtDNA damage. Larger studies are needed to validate our observations
Persistent organochlorine compounds in fetal and maternal tissues: evaluation of their potential influence on several indicators of fetal growth and health
Some organochlorine compounds, such as polychlorinated biphenyls (PCBs), have a tendency to bioaccumulate in humans and predators at the top of the food chain. We have recently confirmed the transplacental transfer of these compounds and the present study has been designed on the same material with the aim of investigating their potential health effects on newborns from 70 pregnant women, resident in a Northern Italy industrial town. Organochlorine compounds [namely, p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethene (p,p'-DDE), hexachlorobenzene (HCB), and PCBs] have been analyzed both in cord and maternal serum, placenta, and maternal subcutaneous adipose tissue by GC-MSD. p,p'-DDT levels in the adipose tissue resulted significantly (p<0.05) related to birth length. Mothers of neonates born by preterm programmed caesarean delivery showed significantly (p<0.005 for both) higher serum p,p'-DDE serum concentrations and p,p'-DDT levels in the adipose tissue, as compared to mothers delivering at term
PARTECIPAZIONE E GRADIMENTO DI UN PERCORSO DI ACCOMPAGNAMENTO PSICOLOGICO RIVOLTO ALLE MATRICOLE DELLA FACOLTÀ DI MEDICINA
Obiettivi: valutare la partecipazione e il gradimento delle matricole che aderiscono al “Progetto Accoglienza”, un percorso di accoglienza e accompagnamento psicologico, attivo da quattro anni, presso il Corso di Laurea in Medicina e Chirurgia dell’Università degli Studi di Brescia.
Metodo: il percorso si fonda sull’implementazione della figura di studenti senior (tutor), adeguatamente formati e supervisionati da docenti della Sezione di Psicologia Clinica, attraverso l’utilizzo di modalità gruppali, in accordo con specifiche metodologie utilizzate da tempo in psicologia clinica. I tutor fungono da riferimenti rassicuranti e identificatori per le matricole, che a loro volta aderiscono al progetto in modo volontario e ricevono crediti opzionali, al fine di riconoscere il valore formativo dello scambio fra studenti del primo anno e studenti senior. Per la valutazione del livello di gradimento è stato predisposto un questionario ad hoc, elaborato in parte sulla base di strumenti utilizzati nei corsi professionali in cui è previsto l’accreditamento e in parte sulla base di proposte e riflessioni fra i docenti di psicologia dell’Ateneo, che non hanno preso parte al progetto.
Risultati: il numero di studenti che partecipa con regolarità al percorso di accoglienza è cresciuto nei quattro anni: da 125 a 164. Gli studenti hanno in media un’età di 19.3 anni (±1.7) e sono in prevalenza femmine. Il questionario di gradimento viene compilato in media dall’85% delle matricole coinvolte. Quasi la totalità di esse riferisce che ripeterebbe l’esperienza, anche senza crediti formativi; il 98% la consiglierebbe ad una nuova matricola. Per quanto riguarda rilevanza, efficacia e utilità del percorso rispetto alle proprie esigenze formative, anche in questo caso la maggior parte degli studenti riporta una valutazione positiva.
Conclusioni: i dati raccolti mostrano un gradimento medio-alto, che si mantiene costante negli anni. Si ritiene che tale percorso possa fornire un aiuto concreto per fronteggiare le difficoltà associate all’ingresso nell’Università. Fra gli indicatori di efficacia di consimili interventi nel lungo periodo, riteniamo utile la ricaduta in termini di prevenzione del drop out e dell’ allungamento temporale del corso di studi
Modulation of cell growth and cisplatin sensitivity by membrane gamma-glutamyltransferase in melanoma cells.
The plasma membrane enzyme c-glutamyltransferase (GGT) is regarded as critical for the
maintenance of intracellular levels of glutathione (GSH). GGT expression has been implicated
in drug resistance through elevation of intracellular GSH. The dependence of intracellular
GSH on GGT expression was not conclusively ascertained. The present study was
designed to investigate the role of GGT and of intracellular GSH levels in modulating proliferation
and sensitivity to cisplatin of melanoma cells. GGT transfection resulted in
increased growth, both in vitro and in tumour xenografts. In addition, GGT-transfected cells
exhibited reduced sensitivity to cisplatin associated with lower DNA platination. A
decrease in intracellular GSH levels, rather than an increase, was observed in GGT-transfected
cells; moreover, in cysteine-deficient conditions, the expression of GGT did not provide
transfected cells with the ability of utilising extracellular GSH. In conclusion, these results
indicate that GGTactivity confers a growth advantage unrelated with intracellular glutathione
supply, and are consistent with the interpretation that cisplatin resistance is the consequence
of modifications of cellular pharmacokinetics as a result of extracellular drug
inactivation by thiol metabolites originated by GGT-mediated GSH cleavage
Effects of inhalable particulate matter on blood coagulation.
BACKGROUND: Particulate matter (PM) exposure has been linked to increased risk of cardiovascular disease, possibly resulting from hypercoagulability and thrombosis. Lung and systemic inflammation resulting from PM inhalation may activate blood coagulation, but mechanisms for PM-related hypercoagulability are still largely unknown. OBJECTIVES: To identify coagulation mechanisms activated by PM in a population with well-characterized exposure. METHODS: We measured prothrombin time (PT), activated partial thromboplastin time, endogenous thrombin potentials (ETPs) with/without exogenous triggers and with/without soluble thrombomodulin, tissue-type plasminogen activator (t-PA) antigen, D-dimer and C-reactive protein (CRP) in 37 workers in a steel production plant with well-characterized exposure to PM with aerodynamic diameter of < 1 mum (PM(1)) and coarse PM (PM(10) - PM(1)). Blood samples were collected from each subject on the first (baseline) and last (postexposure) day of a 4-day work week. We analyzed differences between baseline and postexposure levels using a paired Student's t-test. We fitted multivariate mixed-regression models to estimate the associations of interquartile range PM(1) and coarse PM exposure with parameter levels. RESULTS: None of the parameters showed any significant changes from baseline in postexposure samples. However, exposure levels were associated with shorter PT (beta[PM(1)] = -0.33 s, P = 0.08; beta[PM(coarse)] = - 0.33 s, P = 0.01), and higher ETP without exogenous triggers and with thrombomodulin (beta[PM(1)] = + 99 nm min, P = 0.02; beta[PM(coarse)] = + 66 nm min, P = 0.05), t-PA (beta[PM(1)] = + 0.72 ng mL(-1), P = 0.01; beta[PM(coarse)] = + 0.88 ng mL(-1), P = 0.04), and CRP (beta[PM(1)] = + 0.59 mg L(-1), P = 0.03; beta[PM(coarse)] = + 0.48 mg L(-1), P = 0.01). CONCLUSIONS: PM exposure did not show any short-term effect within the week of the study. The association of PM exposure with PT, ETP and CRP provides some evidence of long-term effects on inflammation and coagulation
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