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The need for increasing the share of sea resources in the global renewable energy market requires a specialized design of wave energy converters and Power Take-Off units that, in turn, may be capable of maximising power production and minimizing extraction costs. In this respect, as optimization of wave energy converter performances, by properly tuning relevant hydrodynamic parameters and controlling the motion in waves, reveals a basic issue to reduce energy production charges, a new cost-based design procedure for heaving point absorber type devices is developed, with the main aim of accounting for wave climate at deployment site, reliable device operational profiles and design restraint criteria for both floating buoy and Power Take-Off unit. The newly proposed cost-based procedure is applied to detect the optimum configuration of heaving point absorber devices at several candidate deployment sites. Finally, the incidence of wave climate and available energy resources, on detecting the optimum device configuration and assessing relevant energy production costs, is investigated and fully discussed.

In the present study on Bubalus bubalis of the Campania Region (Italy) the serum levels of derivatives of reactive oxygen metabolites (d-ROMs), anti-ROM and oxidative stress index (Osi) were evaluated. These data were then related to the seropositive status of the animals against alpha-herpesviruses, precisely Bubaline herpesvirus 1 (BuHV-1) and Bovine herpesvirus 1 (BoHV-1). Clinically healthy Mediterranean buffaloes were selected for this study. The serum samples of these animals were taken, and d-ROMs, anti-ROM and Osi were measured using commercially available tests. The preliminary data demonstrated that animals seropositive to both BuHV-1 and BoHV-1 present more oxidative stress than seronegative animals, as revealed by a significant increase in d-ROMs. Our results provide, for the first time, insight into the reac- tive oxygen species (ROS) modulation induced by the herpesvirus in Bubalus bubalis.

In the present study on Bubalus bubalis of the Campania Region (Italy) the serum levels of derivatives of reactive oxygen metabolites (d-ROMs), anti-ROM and oxidative stress index (Osi) were evaluated. These data were then related to the seropositive status of the animals against alpha- herpesviruses, precisely Bubaline herpesvirus 1 (BuHV-1) and Bovine herpesvirus 1 (BoHV-1). Clinically healthy Mediterranean buffaloes were selected for this study. The serum samples of these animals were taken, and d-ROMs, anti-ROM and Osi were measured using commercially available tests. The preliminary data demonstrated that animals seropositive to both BuHV-1 and BoHV-1 present more oxidative stress than seronegative animals, as revealed by a significant increase in d- ROMs. Our results provide, for the first time, insight into the reactive oxygen species (ROS) modulation induced by the herpesvirus in Bubalus bubalis.

In the literature, the weir boundary condition is usually implemented imposing the weir formula at the boundaries, but this is rigorous only in subcritical steady conditions, and a more general approach is required during transients. With acceptable approximation, the non-submerged broad-crested weir behaves as a bottom step where the energy is conserved and critical conditions are attained at the top. Taking advantage of this observation, the analytic solution of the Riemann problem for the Shallow-water Equations over a dry bottom step is considered in this paper, and the momentum and mass fluxes of the analytic solution of the Riemann problem are used to impose weakly the broad-crested non-submerged weir boundary condition in a Finite Volume scheme.

In this paper, new analytical solutions of the linearized parabolic approximation (LPA) of the De Saint Venant equations (DSVEs) are derived for the case of finite channel length. The new solutions for both discharge and water depth are found taking into account upstream and lateral inflows, and some of possible boundary conditions at the downstream end (a stage-discharge relationship and a time dependent flow depth). The solutions are first determined in the Laplace Transform domain, and the Laplace Transform Inversion Theorem is used in order to find the corresponding time domain expressions. The effects induced on the flow propagation by the downstream boundary condition are analyzed using the new analytical solutions. Finally, a simple flood routing based on the new analytical solutions is applied to some schematic cases and compared with the solution of the full DSVEs, showing that the new solutions can actually account for the effects of the downstream boundary condition on the flow dynamics

The work describes a procedure for the evaluation of the optimal number, positions, configuration and sizes of detention tanks inside urban drainage networks, aiming at containing expensive and troublesome replacement of existing sewers unable to properly convey runoff discharges. The procedure proposed is based on the use of a Genetic Algorithm (GA), in which the evaluation of the behaviour of each individual (i.e., of the entire drainage system, consisting of both the detention tanks inserted in it in place of one of a few existing sewer pipes and remaining existing sewers) is analyzed by a semi-distributed hydrological model, where the flood routing is carried out using a simplified hydraulic model: the kinematic wave approximation of De Saint-Venant equations. In particular, for each individual, the proposed hydraulic-hydrological model is used within a "variational" procedure, based on the evaluation, by varying the rainfall durations and the cor-responding value of the rainfall depths (whose correspondence is given by an intensity-duration-frequency relationship), of the maximum value of the peak discharges and/or flow depths. The pro-posed approach has been applied, for example, in a specific case study, showing its promising potential and its ability to obtain results of practical interest.

A new procedure to optimize the hydrodynamic performances of heaving point absorbers is outlined, with the main aim of maximising the yearly energy production, based on the wave climate representative of the candidate deployment site. Phase control is applied, adding a fully submerged mass to the wave energy converter, to properly shift the device heave natural frequency, gain resonance with the most energetic waves and maximize the energy absorption. The optimization procedure allows for varying the fully submerged added mass and the Power Take Off damping, until the optimum configuration is detected. The incidence of buoy dimensions on both device efficiency and energy production costs is fully discussed and investigated. In this respect, a new parameter, namely the Annualised Energy Production per unit area, is proposed to detect, in a preliminary project phase, the minimum cost configuration, without detailing the device cost breakdown that, in turn, is required to estimate the Levelised Cost of Energy. The optimization procedure is applied to a deployment site located in Tyrrhenian Sea, off Southern Italy coastlines, varying the buoy dimensions in the range 4–8 m, with 1 m step. Both hydrodynamic results, detection of optimum device configuration and cost analysis are fully discussed.

A causa della progressiva antropizzazione dei territori, molto spesso si determinano notevoli incrementi sia nell’estensione che nel grado di impermeabilizzazione delle aree drenate dalle reti fognarie già esistenti, con conseguenti incrementi dei volumi e delle portate massime di origine meteorica in arrivo ai diversi collettori e, quindi, possibili malfunzionamenti delle stesse reti per la loro oramai insufficiente capacità di convogliamento. Una possibile soluzione a tale problema è rappresentata dallo sfruttamento di adeguate capacità di accumulo, create ad hoc all’interno della rete (vere e proprie vasche di laminazione) oppure ottenute recuperando strutture ipogee esistenti, volte ad immagazzinare, temporaneamente, le acque di origine meteorica che pervengono alla rete di drenaggio, per poi rilasciarle, gradualmente, nei tratti fognari posti più a valle. Tenendo presenti tali necessità, e tale tipo di soluzione, nel presente lavoro viene proposta una procedura, basata sull’accoppiamento di un Algoritmo Genetico con un modello idrologico semi-distribuito basato sul modello cinematico, per l’individuazione, in base a criteri di minimo costo e per assegnata affidabilità, del numero di vasche di laminazione da adottare e del loro possibile posizionamento all’interno della rete esistente, nonché per il loro dimensionamento.

Nel presente lavoro viene proposta una procedura per l’individuazione delle regole per la gestione ottimale di serbatoi artificiali ad uso plurimo, basata sull’accoppiamento di un Algoritmo Genetico col ben noto “Metodo degli scarti cumulati”. La massimizzazione dei benefici ritraibili dalla distribuzione della risorsa allocata in un serbatoio artificiale di preassegnato volume utile W*, è ottenuta attraverso l’elaborazione, all’interno di ciascun passo della procedura di ottimizzazione proposta, di una serie di “curve di possibilità di regolazione dei deflussi”. In particolare, le curve di possibilità di regolazione sono generate creando un certo numero di “individui”, ciascuno dei quali caratterizzato da uno specifico set dei valori dei coefficienti di utilizzazione relativi alle diverse utenze da servire, e da un determinato set dei rapporti Eut/E tra l’erogazione annua Eut assegnata a ciascuna utenza e l’erogazione annua complessiva E garantita dal serbatoio, pari alla somma dei diversi valori relativi alle singole utenze. L’approccio, sebbene in grado di portare in conto, nell’immediato futuro, deflussi variabili in modo semialeatorio, è sviluppato, nel presente lavoro, con riferimento ad un approccio puramente deterministico, a partire dalla presunta conoscenza delle disponibilità idriche in n anni consecutivi.

Nel lavoro viene descritto un modello numerico per la soluzione delle Shallow-water Equations, con termine sorgente dovuto alle pendenza del fondo, accoppiate all’equazione di trasporto convettivo di un costituente disciolto. Il metodo numerico proposto, basato sull’approccio dei Volumi Spettrali, soddisfa la C-Property, è preciso al terzo ordine nello spazio e nel tempo, ed è in grado di portare in conto discontinuità del campo di moto nonché le transizioni tra fondo asciutto e fondo bagnato

In questo lavoro viene proposta una metodologia volta a determinare il posizionamento ottimale di un set di stazioni di monitoraggio per la rilevazione di contaminazioni intenzionali della risorsa idrica, in grado di portare in conto la natura casuale della domanda idrica da parte dell’utenza. In particolare, tra tutti i set costituiti da un ugual numero di stazioni di monitoraggio, viene individuato quale “ottimo” quello che minimizza un prefissato frattile della distribuzione di probabilità di un indice di misura del danno, opportunamente definito. La metodologia viene illustrata con riferimento ad un caso studio realistico.

Si riportano i risultati di un’intensa attività sperimentale condotta presso il laboratorio del Dipartimento di Ingegneria Idraulica ed Ambientale “Girolamo Ippolito” dell’Università di Napoli Federico II, rivolta allo studio di un particolare tipo di sfioratore bilaterale, caratterizzato da soglie basse rispetto ai tiranti idrici delle correnti in arrivo. Il comportamento idraulico di questo particolare tipo di dispositivo è stato indagato utilizzando predefinite configurazioni geometriche ed idrauliche del sistema. La vasta campagna sperimentale ha permesso, anche per confronto con i risultati ottenuti, sulla stessa installazione di laboratorio, nel caso di sfioratori monolaterali, di trarre utili considerazioni sul dimensionamento di tale tipo di scaricatore.

Nel presente lavoro si è esaminato fino a che punto l'utilizzazione di un particolare modello semplificato di moto vario, quale quello parabolico linearizzato, può ancora dare la possibilità di individuare, con sufficiente precisione, i massimi tirantiidrici e le massime portate istantanee che possono verificarsi nei diversi tronchi di una rete di drenaggio in conseguenza di eventi di piena. Ciò, anche in considerazione del fatto che tali modelli, seppure in versione estremamente semplificata, sono di norma utilizzati nell'ambito di approcci "variazionali" o "estremanti" in grado di portare in debito conto l'informazione pluviometrica usualmente a disposione, costituita dai massimi annuali delle altezze di pioggia di preassegnate durate e, pertanto, necessitano non tanto di riprodurre perfettamente gli eventi di piena ma, soprattutto, di una buona capacità di individuazione dei picchi dei tiranti idrici e delle portate.

A novel class of synthetic, multisite-directed thrombin inhibitors, known as hirunorms, has been described recently. These compounds were designed to mimic the binding mode of hirudin, and they have been proven to be very strong and selective thrombin inhibitors. Here we report the crystal structure of the complex formed by human alpha-thrombin and hirunorm V, a 26-residue polypeptide containing non-natural amino acids, determined at 2.1 A resolution and refined to an R-factor of 0.176. The structure reveals that the inhibitor binding mode is distinctive of a true hirudin mimetic, and it highlights the molecular basis of the high inhibitory potency (Ki is in the picomolar range) and the strong selectivity of hirunorm V. Hirunorm V interacts through the N-terminal tetrapeptide with the thrombin active site in a nonsubstrate mode; at the same time, this inhibitor specifically binds through the C-terminal segment to the fibrinogen recognition exosite. The backbone of the N-terminal tetrapeptide Chg1"-Val2"-2-Nal3"-Thr4" (Chg, cyclohexyl-glycine; 2-Nal, beta-(2-naphthyl)-alanine) forms a short beta-strand parallel to thrombin main-chain residues Ser214-Gly219. The Chg1" side chain fills the S2 subsite, Val2" is located at the entrance of S1, whereas 2-Nal3" side chain occupies the aryl-binding site. Such backbone orientation is very close to that observed for the N-terminal residues of hirudin, and it is similar to that of the synthetic retro-binding peptide BMS-183507, but it is opposite to the proposed binding mode of fibrinogen and of small synthetic substrates. Hirunorm V C-terminal segment binds to the fibrinogen recognition exosite, similarly to what observed for hirudin C-termninal tail and related compounds. The linker polypeptide segment connecting hirunorm V N-and C-terminal regions is not observable in the electron density maps. The crystallographic analysis proves the correctness of the design and it provides a compelling proof on the interaction mechanism for this novel class of high potency multisite-directed synthetic thrombin inhibitors.

Viene proposta una metodologia d’analisi finalizzata alla valutazione dei fenomeni dissipativi localizzati che si sviluppano in corrispondenza di un particolare tipo di dispositivo adottato per la mitigazione degli effetti dei fenomeni di colata, e alla quantificazione delle spinte complessivamente agenti su singoli elementi che lo compongono. Il dispositivo, sostanzialmente costituito da blocchi paralleli, a pianta quadrata, tra loro identici, disposti, con prefissato interasse, trasversalmente alla corrente, è facilmente utilizzabile in aree a valle di canaloni e, pertanto, riveste un certo interesse dal punto di vista applicativo. Allo scopo di poterne studiare gli effetti, e di mettere a punto delle relazioni di dimensionamento piuttosto semplici, seppure fisicamente basate, nel presente lavoro si affronta il problema di calibrare alcune relazioni, fondamentalmente a carattere teorico in quanto basate sulle classiche equazioni di bilancio della massa e della quantità di moto, alla luce di risultati ottenuti dalla reiterata applicazione di un modello numerico bidimensionale appositamente adattato al fine di portare in conto anche gli scambi turbolenti che si verificano nel piano orizzontale. Procedendo in tal modo, si giunge a semplici relazioni che, seppure con riferimento a condizioni di moto permanente, permettono di legare la spinta applicata agli ostacoli e l’entità delle dissipazioni concentrate derivante dall’interazione di tali ostacoli con le correnti detritiche ai caratteri idrodinamici della corrente e alla geometria del dissipatore.

Nel lavoro si procede a verificare la possibilità di utilizzare un approccio di tipo variazionale. o "estremante", per la stima dei massimi tiranti idrici e delle massime portate al colmo che possono realizzarsi nelle reti di drenaggio in conseguenza di eventi meteorici estremi.

Vengono descritti ed analizzati i risultati di una serie di esperienze eseguite, su canaletta di laboratorio, presso il Dipartimento di Ingegneria Idraulica ed Ambientale "Girolamo Ippolito" dell'Università di Napoli Federico II, che confermano i risultati già trovati da altri autori agli inizi degli anni '90, quali Mayerle, Novak e Nalluri.

Vengono proposti una serie di indici per la valutazione dell'affidabilità idraulica e meccanica delle reti di distribuzione idrica, proponendo un approccio per la valutazione dell'affidabilità complessiva 8idraulica + meccanica) delle stesse.

The X-ray crystal structure of the human alpha-thrombin-hirunorm IV complex has been determined at 2.5 A resolution, and refined to an R-factor of 0.173. The structure reveals an inhibitor binding mode distinctive of a true hirudin mimetic, which justifies the high inhibitory potency and the selectivity of hirunorm IV. This novel inhibitor, composed of 26 amino acids, interacts through the N-terminal end with the alpha-thrombin active site in a nonsubstrate mode, and binds specifically to the fibrinogen recognition exosite through the C-terminal end. The backbone of the N-terminal tripeptide Chg1"-Arg2"-2Na13" (Chg, cyclohexyl-glycine; 2Na1, beta-(2-naphthyl)-alanine) forms a parallel beta-strand to the thrombin main-chain segment Ser214-Gly216. The Chg1" side chain occupies the S2 site, Arg2" penetrates into the S1 specificity site, while the 2Na13" side chain occupies the aryl binding site. The Arg2" side chain enters the S1 specificity pocket from a position quite apart from the canonical P1 site. This notwithstanding, the Arg2" side chain establishes the typical ion pair with the carboxylate group of Asp189.

Connexin (Cx) channels are sites of cytoplasmic communication between contacting cells. Evidence indicates that the opening of hemichannels occurs under both physiological and pathological conditions. In this paper, the involvement of Cx-43 hemichannels is demonstrated in the pathogenesis of Yersinia . Parental HeLa cells and transfected HeLa cells stably expressing Cx-43 (HCx43) were infected with Yersinia enterocolitica , and bacterial uptake was measured by the colony-forming unit method. Bacterial uptake was higher in HCx43 cells than in parental cells and was inhibited by the Cx channel blocker, 18-α-glycyrrhetinic acid (AGA). The inhibitory effect of AGA was more pronounced on the Y. enterocolitica uptake by HCx43 cells than by parental cells. The ability of HCx43 cells to incorporate the permeable fluorescent tracer Lucifer Yellow (LY) was assessed. Dye incorporation was inhibited by AGA, whereas Y. enterocolitica infection of HCx43 cells increased LY incorporation. Western blotting analysis demonstrated that Y. enterocolitica infection of HCx43 cells induced tyrosine phosphorylation of Cx-43, thus supporting a critical role for Cx-43 in the strategies exploited by bacterial pathogens to invade non-phagocytic cells.

We describe here the design, synthesis, and activity of a novel class of alpha-thrombin inhibitors named hirunorms. They were rationally designed to interact through their N-terminal end with the alpha-thrombin active site in a nonsubstrate mode and to specifically bind the fibrinogen recognition exosite. An appropriate spacer that is able to properly orient the N-terminal end in the active site was also selected. This spacer allowed the size of the inhibitors to be reduced to about one-third of the amino acid residues in the hirudin sequence. Hirunorms specifically inhibit the amidolytic action of human alpha-thrombin toward a small chromogenic substrate. The most active compounds of the series, hirunorms IV and V, inhibit alpha-thrombin catalyzed hydrolysis of Tos-Gly-Pro-Arg-p-nitroanilide with K(i) = 0.09 and K(i) = 0.21 nM, respectively. Comparison of the anticoagulant properties of hirunorms, natural hirudin from the European leech Hirudo medicinalis, and the synthetic analog hirulog-1 revealed that hirunorm IV is about 10-fold and 3-fold more active, on a molar base, than hirudin and hirulog-1 in increasing the aPTT, PT, and TT of normal human plasma. The peculiar structure of hirunorms makes them stable to the amidolytic action of thrombin without the introduction of any peptide bond modification. These molecules display long-lasting activity in human plasma, due to the presence of several unnatural amino acids in susceptible positions. Hirunorms are potential candidates for injectable anticoagulants, due to their potency, specificity of action, long-lasting activity, and safety profiles.

First, the discussers would like to congratulate the authors for theclarity of the discussion and for the results obtained, which arevery useful from a technical point of view and throw light on thetopic considered in the paper.Because the discussers have considerable experience in evalu-ating both the removal capacity ~Biggiero and Della Morte 1996!and the transport capacity on cohesionless sediments depositedover fixed beds~Biggiero et al. 2000!, they consider it useful todiscuss the results obtained by the authors, providing a furthercontribution to the second topic.The experiences considered in this discussion were accom-plished at the Lab of the Hydraulic and Environmental Dept. ofthe Univ. of Naples Federico II at the end of the 1990s. A plexi-glas channel, 18 m long and 0.76 m wide constituted the equip-ment used for the accomplishment of the tests ~Fig. 1 here!.The water discharges considered in the experiments varied be-tween 0.020 m

Conflicting data on platelet function in animal species are reported in the literature. In this study, the response of buffalo, horse, pig and sheep platelets to different agonists was assessed. Blood samples were collected from the jugular vein of six healthy subjects of each species and platelet-rich plasma was obtained by centrifugation. Platelet aggregation responses to increasing doses of adenosine 5'-diphosphate (ADP), arachidonic acid, collagen, platelet activating factor (PAF) and ristocetin were measured by a turbidimetric method. Horse platelets were the most responsive to ADP, collagen and PAF, whereas sheep platelets were the most responsive to ristocetin. The response to arachidonic acid varied least between species. PAF was the most effective agonist, inducing a maximum aggregation response at a concentration of 1 micro M for platelets of each species. Conversely, concentrations of ristocetin higher than 1mg/ml induced a maximum aggregation response only with sheep and horse platelets. The different responses of platelets from the four animal species to various agonists may reflect either (1). structural differences (including composition of the platelet membrane and presence of specific agonist receptors), or (2). activation of distinct signalling pathways by the agonist.

Fumonisin B1 (FB1), a mycotoxin produced by the corn fungus Fusarium moniliforme , causes a variety of animal diseases and is a suspected human carcinogen. The FB1 molecule bears remarkable structural resemblance to the long-chain sphingoid base backbones of sphingolipids. The toxicity and carcinogenicity of FB1 has been ascribed to its ability to inhibit ceramide synthase, a key enzyme in the metabolism of complex sphingolipids. In this study we have investigated whether the exposure of B16-BL6 mouse melanoma cells to FB1 affects cell growth and integrin-mediated cell matrix adhesion. Cell treatment with the highest tested dose (75 μM) of FB1 for 72 h induced an about 20% inhibition of cell growth. FB1 strongly affected B16-BL6 cell adhesion to immobilized fibronectin, by causing a dose-dependent inhibition of cell attachment to this substrate. FB1 also inhibited in a dose-dependent manner the adhesion of B16-BL6 cells to the immobilized anti-fibronectin receptor antibody, whereas it affected only to a low extent cell attachment to concanavalin A. Our results demonstrate that FB1 treatment alters integrin adhesive activity, thus affecting all cellular integrin-dependent functions.

The adhesion of ADP-stimulated platelets to immobilized fibrinogen induces the tyrosine phosphorylation of multiple proteins which include pp72 syk and pp125 FAK . The phosphorylation of these two proteins increases as function of time of platelet adhesion to fibrinogen; however, pp72 syk results strongly phosphorylated already after 15 min. whereas pp125 FAK reaches high levels of phosphorylation after 1 h of platelet adhesion. Phosphorylation of both proteins is only slightly detectable when platelets are held in suspension or when platelets are allowed to adhere to bovine serum albumin, a non-specific substrate. Echistatin, an Arg-Gly-Asp (RGD)-containing snake-venom protein, affects protein tyrosine phosphorylation promoted by platelet adhesion to fibrinogen, by causing an approximately 44% and 39% decrease of pp72 syk and pp125 FAK phosphorylation, respectively. The interaction of echistatin with fibrinogen receptor glycoprotein Ilb-Illa on platelet surface might be responsible for the block of integrin-mediated signaling cascade, including pp72 syk and pp125 FAK inactivation.

Exposure of fibrinogen to the Fe3+/ascorbate oxidative system resulted in structural modifications and altered functionality of the glycoprotein. The overnight treatment of fibrinogen by oxidants caused a 20-fold increase of carbonyl content with respect to the native protein. Formation of dityrosines as well as loss of tryptophan following fibrinogen oxidation were observed. The occurrence of conformational changes of the fibrinogen molecule as a consequence of the oxidative treatment was also established. Oxidized fibrinogen showed a distinct capability from the native molecule to mediate platelet aggregation and adhesion. The percentage of ADP-induced platelet aggregation decreased as a function of fibrinogen oxidative damage. Further, both unstimulated platelets and ADP-activated platelets showed a reduced ability to adhere to oxidized fibrinogen than to the native protein. These results suggest that oxidative treatment alters fibrinogen domains involved in the recognition and the binding of this molecule by the platelet receptor GP IIb/IIIa.

Low-molecular-mass Arg-Gly-Asp (RGD)-containing polypeptides were isolated from the venom of Trimeresurus elegans by a simple two-step procedure consisting of membrane filtration and reverse-phase HPLC. A combination of electrospray MS, fast-atom bombardment MS and Edman degradation allowed us to ascertain the presence in the venom of different isoforms and to determine their primary structures. The amino acid sequences resembled the structure of elegantin, the only disintegrin previously reported from the T. elegans venom [Williams, Rucinski, Holt and Niewiarowski (1990) Biochim. Biophys. Acta 1039, 81–89]. MS analyses indicated the occurrence of differential proteolytic processing at both the N-terminus and the C-terminus of the polypeptide chains. The amino acid sequence alignment of the elegantin isoforms with known components of the disintegrin family demonstrated the complete conservation of the 12 cysteine residues involved in disulphide bridges. Molecular modelling of elegantins predicted an overall folding of these molecules quite similar to that reported for the kistrin solution structure. The newly identified polypeptide isoforms strongly inhibited ADP-induced aggregation in both human and canine platelet-rich plasma but showed a different species-dependent specificity. These molecules were also able to inhibit B16-BL6 murine melanoma cell adhesion to immobilized fibronectin. The comparison of the structures and biological activities of elegantin isoforms and kistrin allowed us to highlight some structural features that, in addition to the RGD locus, might be involved in the interaction of these snake-venom polypeptides with the integrin receptors on the platelet and cell surface.

A symposium report on the synthesis of hirudin analogs for use as a-thrombin inhibitors.

1-Amino-8-nitropyrene (1,8-ANP), a product of 1,8-dinitropyrene metabolism by either bacterial or mammalian enzymes, is weakly mutagenic to the 'classical nitroreductase'-deficient Salmonella tester strain TA98NR. The addition to the test system of rat liver cytosol without cofactors did not produce any effect on the 1,8-ANP mutagenic response toward TA98NR strain. Conversely, when both rat hepatic cytosol and NADPH (1 mM) were added to the mutagenicity assay, a 10-fold increase in 1,8-ANP mutagenic activity was observed. This suggests the involvement of rat hepatic cytosolic NADPH-dependent nitroreductase(s) in 1,8-ANP mutagenic activation. The addition to the mutagenesis assay of pentachlorophenol, an inhibitor of O-acetyltransferase and sulfotransferase, produced a dose-dependent decrease of 1,8-ANP mutagenic activation, whereas 2,6-dichloro-4-nitrophenol, a more specific inhibitor of sulfotransferase than O-acetyltransferase, did not affect the activation of 1,8-ANP to a mutagen at concentrations that selectively inhibit only bacterial sulfotransferase. This indicates that bacterial O-acetyltransferase but not sulfotransferase plays a role in the mutagenic activation of 1,8-ANP. Addition of acetyl co-enzyme A (AcCoA) and adenosine 3'-phosphate 5'-phosphosulfate (PAPS), cofactors for O-acetyl-transferase and sulfotransferase respectively, to the test system caused a dose-dependent inhibition of 1,8-ANP mutagenic activation by rat liver cytosol and NADPH, probably due to the formation of highly reactive O-acetoxy and N-sulfate ester derivatives of 1,8-ANP, which react with nucleophilic sites before reaching bacterial DNA. This hypothesis was confirmed by DNA covalent binding in in vitro experiments showing that both the cofactors AcCoA and PAPS enhanced the NADPH/rat liver cytosol-mediated covalent binding of 1,8-ANP to DNA from calf thymus 10- and 3-fold respectively. It seems likely that rat hepatic cytosolic nitroreductases activate 1,8-ANP to an N-hydroxyarylamine derivative which can be further metabolized to mutagenic species by either bacterial or mammalian O-acetyltransferase.

Nitrofluoranthenes (NFs) are mutagenic and carcinogenic environmental pollutants found in incomplete combustion products and urban air particulate. We have studied both oxidative and reductive metabolism in vitro of different NF isomers mediated by subcellular rat liver fractions. Under aerobic conditions only ring hydroxylation of NFs by rat liver microsomes occurred and the isomeric position of the nitro group affected both the amount and the type of phenolic metabolites formed. Liver microsomes from 3-methylcholanthrene-induced rats were most effective in giving ring hydroxylated 7- and 8-nitrofluoranthene, whereas liver microsomes from phenobarbital-pretreated rats were the most active in metabolizing 1- and 3-nitrofluoranthene. Under anaerobic conditions, only reduction of NFs mediated by both cytosolic and microsomal rat liver enzymes occurred. Cofactor requirements and inhibition experiments indicated that the reductase activity in rat liver cytosolic fractions could be ascribed to DT-diaphorase, aldehyde oxidase and/or other unknown enzymes. The microsomal reductase activity was inhibited by oxygen, carbon monoxide, 2-diethylaminoethyl-2,2-diphenylvalerate hydrochloride and n-octylamine, and slightly by cytochrome c; flavin mononucleotide greatly enhanced this activity. 3-Nitrofluoranthene microsomal nitroreductase activity was increased by phenobarbital rat pretreatment and this increment correlated well with the content of cytochrome P450. These results indicate a participation of cytochrome P450 in the reductive metabolism of NFs by rat liver microsomes.

Sourcerecord Id Scopus 18967

A few experiments were carried out, in a 1:1 scale laboratory flume, to evaluate, by the acquisition and processing of photographic images, the capability of currents flowing in a stream to remove cohesive sediments deposited on the bed of a river. The results of the experiments, expressed in terms of area and volume eroded, and changes in the concentration of suspended sediments carried by water, were consistent with the physical phenomenon, and congruous with others results already reported in the literature. Con-sidering the goodness of the results obtained by the experiments carried out, it was possible to assert that the procedure adopted for the evaluation of sediment removal is suitable for studying the erosion and transport phenomena involving most kinds of granular or cohesive sediments.

The mutagenic activity of Flunitrazepam, the active ingredient of the drug Rohypnol, has been investigated by using the Salmonella/microsome mutagenicity test. A dose-related mutagenic effect was observed on Salmonella typhimurium strain TA 100 either in the absence or in the presence of a rat liver microsomal fraction (S9) as in vitro metabolic activation system. By adopting a modification of the Salmonella test, the mutagenicity of urines from rats or patients treated with the drug was evaluated. In these cases mutagenic activity was detected toward the Salmonella strains TA 98 and TA 100 both in presence and in absence of the metabolic activation system. The data indicate that Flunitrazepam and/or its urinary metabolites can induce both base-pair substitutions or frame-shift point mutations.

The antitumor drugs ifosfamide (IF) and trofosfamide (TF) were evaluated for their capability to induce sperm abnormalities in (C3H X C57BL/6)F1 mice. A statistically significant increase in teratospermia was observed at the 35th day after 5 daily consecutive intraperitoneal injections of the drugs at doses of 25, 50, 100 mg/kg b.w. of TF and 100 mg/kg b.w. of IF. Thus, IF and TF are able to interfere with the differentiation process of spermatogenic cells.

DNOC, Ferbam and Imidan were tested in (C3H × C57BL/6) F 1 mice to assess their potential testicular toxicity. Chemicals were administered i.p. and per os at different doses for 5 consecutive days. After 35 days the testicular toxicity was evaluated by measuring the testicular weights, the sperm counts and the percentage of abnormal sperm. DNOC and Imidan failed to induce teratospermia in mice treated by both routes of administration. Conversely Ferbam induced a statistically significant increase in teratospermia only following per os administration to mice at a dose of 1000 mg/kg b.w./day. These data indicate that per os administration of Ferbam succeeded in producing active metabolites able to interfere with the differentiation process of spermatogenic cells.

Cyclophosphamide (CP), a widely used antineoplastic drug, requires hepatic mixed-function-oxidase-mediated activation to show alkylating activity as well as cytotoxicity, oncogenic transformation and chromosomal aberrations. Evidences are here reported that in vivo activation of CP to urinary mutagenic metabolites is catalyzed primarily by a phenobarbital-inducible cytochrome P-450 system. 24 hours urines from male Sprague-Dawley rats treated i.p. by a single CP administration were filtered through XAD-2 columns and mutagenicity of the acetonic extract was assayed by the Ames test in absence of enzymatic microsomal activation. a highly positive response with a linear dose-dependence was obtained in the range 0.500 mg/kg of CP. Treating rats with Phenobarbital, before CP (500 mg/kg) administration, induced a 250% increase in urine mutagenic activity, whereas. -Naphthoflavone pretreatment reduced the CP activation to urine mutagenic metabolites to 51% as compared with control CP-treated rats.