Temperature adaptation of glutathione S-transferase P1-1. A case for homotropic regulation of substrate binding.

Human glutathione S-transferase P1-1 (GST P1-1) is a homodimeric enzyme expressed in several organs as well as in the upper layers of epidermis, playing a role against carcinogenic and toxic compounds. A sophisticated mechanism of temperature adaptation has been developed by this enzyme. In fact, above 35 degrees C, glutathione (GSH) binding to GST P1-1 displays positive cooperativity, whereas negative cooperativity occurs below 25 degrees C. This binding mechanism minimizes changes of GSH affinity for GST P1-1 because of temperature fluctuation. This is a likely advantage for epithelial skin cells, which are naturally exposed to temperature variation and, incidentally, to carcinogenic compounds, always needing efficient detoxifying systems. As a whole, GST P1-1 represents the first enzyme which displays a temperature-dependent homotropic regulation of substrate (e.g. GSH) binding

Anti-Invasive Activity of Bovine Lactoferrin against Listeria monocytogenes.

We have investigated the possible role of bovine lactoferrin in protecting the intestinal epithelium from bacterial infections, using as an in vitro model enterocyte-like cell lines HT-39 and Caco-2 infected with a food-borne pathogen, Listeria monocytogenes . When infection occurred in the presence of 1 mg/ml of bovine lactoferrin, in the form of apolactoferrin or iron- or manganese-saturated forms, the adhesion of bacteria to eukaryotk cells was unaffected, but the number of internalized bacteria was reduced by 42- to 125-fold. The possibility of a toxic effect of lactoferrin was excluded, because bovine lactoferrin was used at nonbactericidal and noncytotoxic concentrations

Catalytic mechanism and role of hydroxyl residues in the active site of theta class Glutathione-S-Transferases: Investigation of Ser-9 and Tyr-113 in a Glutathione S-Transferase from the australian sheep blowfly Lucilia cuprina

Abstract Spectroscopic and kinetic studies have been performed on the Australian sheep blowfly Lucilia cuprina glutathione S-transferase (Lucilia GST; EC 2.5.1.18) to clarify its catalytic mechanism. Steady state kinetics of Lucilia GST are non-Michaelian, but the quite hyperbolic isothermic binding of GSH suggests that a steady state random sequential Bi Bi mechanism is consistent with the anomalous kinetics observed. The rate-limiting step of the reaction is a viscosity-dependent physical event, and stopped-flow experiments indicate that product release is rate-limiting. Spectroscopic and kinetic data demonstrate thatLucilia GST is able to lower the pK a of the bound GSH from 9.0 to about 6.5. Based on crystallographic suggestions, the role of two hydroxyl residues, Ser-9 and Tyr-113, has been investigated. Removal of the hydroxyl group of Ser-9 by site-directed mutagenesis raises the pK a of bound GSH to about 7.6, and a very low turnover number (about 0.5% of that of wild type) is observed. This inactivation may be explained by a strong contribution of the Ser-9 hydroxyl group to the productive binding of GSH and by an involvement in the stabilization of the ionized GSH. This serine residue is highly conserved in the Theta class GSTs, so the present findings may be applicable to all of the family members. Tyr-113 appears not to be essential for the GSH activation. Stopped-flow data indicate that removal of the hydroxyl group of Tyr-113 does not change the rate-limiting step of reaction but causes an increase of the rate constants of both the formation and release of the GSH conjugate. Tyr-113 resides on α-helix 4, and its hydroxyl group hydrogen bonds directly to the hydroxyl of Tyr-105. This would reduce the flexibility of a protein region that contributes to the electrophilic substrate binding site; segmental motion of α-helix 4 possibly modulates different aspects of the catalytic mechanism of theLucilia GST

The PON “Reti e mobilità” and the objectives of Sustainability: the role of the Environmental Monitoring Plan.

Il  PON Reti e mobilità 2007-2013 (PON) è stato approvato dalla Commissione Europea con decisione C(2007)6318 del 7 dicembre 2007.La strategia del Programma, rivolto alle Regioni “Obiettivo Convergenza” (Campania, Calabria, Sicilia, Puglia) si  concretizza con interventi tesi a sviluppare l’intermodalità, a migliorare la mobilità e l’accessibilità anche per controllare e attenuare i fenomeni di congestione e a garantire la riduzione degli impatti ambientali delle infrastrutture di trasporto, in particolare in termini di riduzione delle emissioni di sostanze inquinanti attraverso il miglioramento complessivo della qualità e dell’efficienza del sistema dei trasporti con specifico riferimento alle merci.Appare dunque evidente come il PON Reti e mobilità tenga fortemente in conto i principi di sostenibilità affermati a livello europeo, non ultimi, quelli sottesi nel Libro Bianco dei Trasporti pubblicato nel 2011 dalla Commissione Europea. A conferma di una strategia complessiva del Programma improntata sulla sostenibilità ambientale, il PON Reti e mobilità destina oltre il 70% delle risorse programmate (cfr. Decreto dell’Autorità di Gestione del 28 luglio 2011) alla realizzazione di interventi relativi a modalità di trasporto sostenibili così come individuate a livello europeo (ferrovie, porti, trasporti multimodali e sistemi di trasporto intelligente).Il PON Reti e mobilità è stato sottoposto a procedura di VAS in accordo a quanto previsto dalla Direttiva 2001/42/CE del 27 giugno 2001, recepita in Italia con D. Lgs 152/2006 “Norme in materia ambientale”, successivamente modificato con D. Lgs 4/2008 e D. Lgs 128/2010.Nel Rapporto Ambientale della VAS del PON grande attenzione è dedicata all’attività di monitoraggio, come dimostra la previsione di  “adeguate misure per il monitoraggio ambientale, anche al fine di apportare eventuali misure correttive nella fase di attuazione”. Un primo e rilevante passaggio in tal senso è rappresentato dall’elaborazione del Piano di Monitoraggio Ambientale (PMA), che costituisce il principale documento di riferimento per la successiva implementazione delle attività di monitoraggio.In questo articolo, a valle della presentazione del Programma e dell’indicazione degli obiettivi di sostenibilità ambientale che si intendono perseguire attraverso l’attuazione degli interventi finanziati, verrà dunque illustrato il PMA, adottato dal Ministero delle Infrastrutture e dei Trasporti (Autorità di Gestione del PON) nel  febbraio 2011 che si pone nel panorama italiano come esperienza pilota nel campo del monitoraggio soprattutto dal punto di vista metodologico.The National Operative Program (PON) “Reti e mobilità” has been approved by European Commission on the 7th of December 2007.The strategic  approach of the PON, exclusively devoted to the  so-called “convergence regions” of Italy (Campania, Calabria, Sicilia, Puglia), aims to:1.    improve the modal balance by an economic, social and environmental perspective;2.    develop the inter-modality in order to move towards the integration of convergence area into the network of the European transport system;3.    improve the mobility and the accessibility, also to reduce the traffic congestion;4.    increase the efficiency related to security standards, to management techniques and to the quality of transportation services in the sector of freight; 5.    guarantee the reduction of environmental impacts through a global improvement of the efficiency of the transport systems.In such a way it is clear that the PON “Reti e mobilità”  takes greatly into account the Sustainability principles recognized at European scale as attested by the budget, namely over the 70% of the entire fund, associated with low-impacts infrastructures (railways and harbors). The PON has been submitted to the SEA procedure, following what the 2001/42/CE Directive establishes.The Environmental Report of PON devotes  great attention to the monitoring activity as shown by the reported recommendation about the need for adequate measures for the environmental monitoring, also in order to apply corrective measures during the implementation of the program. By this point of view, a first and important step has been the elaboration of the “Environmental Monitoring Plan”  (EMP) that represents the main methodological  document for the following implementation of the monitoring activity.This paper, after a brief presentation of the program and of the objectives of Sustainability that the Programs aims to pursue through the realization of specific projects, is devoted to introduce the Environmental Monitoring Plan of the PON that has been approved by the Ministry of the Infrastructures and Transport -in charge as Management Authority of the PON- in February 2011. In detail, the PMA represents the tool through which, the Management Authority, that has specific responsibilities and functions in terms of monitoring and environmental assessment of the program, controls the significant impacts on the environment caused by the implementation of the PON and verify the level of achievement of the established objectives of environmental sustainability. The structure of EMP is based on three main aspects:1)  the adoption of the results of other interesting experiences carried out by experts institutions on the topic;2)  an approach favoring the creation of an “integrated” monitoring system with  the others Operative Programs activated at regional scale;3)  the implementation of a cooperation and shared process with all the directly-involved actors

A machine-learning based bio-psycho-social model for the prediction of non-obstructive and obstructive coronary artery disease

Background: Mechanisms of myocardial ischemia in obstructive and non-obstructive coronary artery disease (CAD), and the interplay between clinical, functional, biological and psycho-social features, are still far to be fully elucidated. Objectives: To develop a machine-learning (ML) model for the supervised prediction of obstructive versus non-obstructive CAD. Methods: From the EVA study, we analysed adults hospitalized for IHD undergoing conventional coronary angiography (CCA). Non-obstructive CAD was defined by a stenosis < 50% in one or more vessels. Baseline clinical and psycho-socio-cultural characteristics were used for computing a Rockwood and Mitnitski frailty index, and a gender score according to GENESIS-PRAXY methodology. Serum concentration of inflammatory cytokines was measured with a multiplex flow cytometry assay. Through an XGBoost classifier combined with an explainable artificial intelligence tool (SHAP), we identified the most influential features in discriminating obstructive versus non-obstructive CAD. Results: Among the overall EVA cohort (n = 509), 311 individuals (mean age 67 ± 11 years, 38% females; 67% obstructive CAD) with complete data were analysed. The ML-based model (83% accuracy and 87% precision) showed that while obstructive CAD was associated with higher frailty index, older age and a cytokine signature characterized by IL-1β, IL-12p70 and IL-33, non-obstructive CAD was associated with a higher gender score (i.e., social characteristics traditionally ascribed to women) and with a cytokine signature characterized by IL-18, IL-8, IL-23. Conclusions: Integrating clinical, biological, and psycho-social features, we have optimized a sex- and gender-unbiased model that discriminates obstructive and non-obstructive CAD. Further mechanistic studies will shed light on the biological plausibility of these associations. Clinical trial registration: NCT02737982

The Sex-Specific Detrimental Effect of Diabetes and Gender-Related Factors on Pre-admission Medication Adherence Among Patients Hospitalized for Ischemic Heart Disease: Insights From EVA Study

Background: Sex and gender-related factors have been under-investigated as relevant determinants of health outcomes across non-communicable chronic diseases. Poor medication adherence results in adverse clinical outcomes and sex differences have been reported among patients at high cardiovascular risk, such as diabetics. The effect of diabetes and gender-related factors on medication adherence among women and men at high risk for ischemic heart disease (IHD) has not yet been fully investigated.Aim: To explore the role of sex, gender-related factors, and diabetes in pre-admission medication adherence among patients hospitalized for IHD.Materials and Methods: Data were obtained from the Endocrine Vascular disease Approach (EVA) (ClinicalTrials.gov Identifier: NCT02737982), a prospective cohort of patients admitted for IHD. We selected patients with baseline information regarding the presence of diabetes, cardiovascular risk factors, and gender-related variables (i.e., gender identity, gender role, gender relations, institutionalized gender). Our primary outcome was the proportion of pre-admission medication adherence defined through a self-reported questionnaire. We performed a sex-stratified analysis of clinical and gender-related factors associated with pre-admission medication adherence.Results: Two-hundred eighty patients admitted for IHD (35% women, mean age 70), were included. Around one-fourth of the patients were low-adherent to therapy before hospitalization, regardless of sex. Low-adherent patients were more likely diabetic (40%) and employed (40%). Sex-stratified analysis showed that low-adherent men were more likely to be employed (58 vs. 33%) and not primary earners (73 vs. 54%), with more masculine traits of personality, as compared with medium-high adherent men. Interestingly, women reporting medication low-adherence were similar for clinical and gender-related factors to those with medium-high adherence, except for diabetes (42 vs. 20%, p = 0.004). In a multivariate adjusted model only employed status was associated with poor medication adherence (OR 0.55, 95%CI 0.31–0.97). However, in the sex-stratified analysis, diabetes was independently associated with medication adherence only in women (OR 0.36; 95%CI 0.13–0.96), whereas a higher masculine BSRI was the only factor associated with medication adherence in men (OR 0.59, 95%CI 0.35–0.99).Conclusion: Pre-admission medication adherence is common in patients hospitalized for IHD, regardless of sex. However, patient-related factors such as diabetes, employment, and personality traits are associated with adherence in a sex-specific manner

Anti-invasive activity of bovine lactoferrin towards group A streptococci

Group A streptococci (GAS) are able to invade cultured epithelial and endothelial cells without evidence of intracellular replication. GAS, like other facultative intracellular bacterial pathogens, evolved such ability to enter and to survive within host cells avoiding the host defences, and bacterial intracellular survival could explain the recurrence of infections. We report here that 1 mg bovine lactoferrin (bLf)/mL significantly hindered the in vitro invasion of cultured epithelial cells by GAS isolated from patients suffering from pharyngitis and completely inhibited the invasiveness of GAS pretreated with subinhibiting concentrations of erythromycin or ampicillin. One milligram of bLf per millilitre was also able to increase the number of epithelial cells undergoing apoptosis following GAS invasion, although the number of intracellular GAS in the presence of bLf decreased by about 10-fold. The ability of bLf to decrease GAS invasion was confirmed by an in vivo trial carried out on 12 children suffering from pharyngitis and already scheduled for tonsillectomy. In tonsil specimens from children treated for 15 days before tonsillectomy with both oral erythromycin (500 mg t.i.d. (three times daily)) and bLf gargles (100 mg t.i.d.), a lower number of intracellular GAS was found in comparison with that retrieved in tonsil specimens from children treated with erythromycin alone (500 mg t.i.d.)

Non-alcoholic fatty liver syndrome: A hepatic consequence of common metabolic diseases

Background and Aims: The association of liver steatosis with a number of common metabolic conditions has been suggested. The aim of the present study was to evaluate the clinical features of subjects with different severities of steatosis. Methods: The present study was performed in 282 consecutive patients with 'bright liver' at ultrasonography and in 58 subjects without steatosis. They had no history of alcohol abuse and negative tests for the presence of hepatitis B and C virus. Patients underwent clinical examination, anthropometry, laboratory tests and routine liver ultrasonography. Steatosis was graded as absent, mild, moderate and severe. Results: A progressive increase in the prevalence of obesity (P < 0.001), type 2 diabetes (P < 0.001), alanine aminotransferase (ALT) elevation (P < 0.001) and hypertriglyceridemia (P < 0.001), and a decrease of hypercholesterolemia (P < 0.05) was observed from the control group to the groups with mild, moderate and severe steatosis. More than half the subjects with liver steatosis had insulin resistance metabolic syndrome. Obesity, diabetes and hypertriglyceridemia were more common by 5.3-fold, 4.0-fold, and 6.7-fold, respectively, in subjects with severe steatosis, as compared to controls. Prevalence of obesity, diabetes and hyperlipidemia was significantly higher in subjects with fatty liver and ALT elevation. Conclusion: Fatty liver can be considered as the hepatic consequence of common metabolic diseases. (C) 2003 Blackwell Publishing Asia Pty Ltd

A new ternary alloy Ti26Zr24Nb for biomedical application : behavior in corrosion, wear, and tribocorrosion

Titanium (Ti)-based alloys with only β-phase have arisen the interest of academics and industrials for bone implants due to their mechanical properties close to those of hard tissues, and for the capability of allowing with β-stabilizers, totally biocompatible elements like Nb, Ta, and Zr. However, there is no consensus about the most adequate composition and, in many cases, tribocorrosion behavior is not considered during their development. New ternary alloy Ti26Zr24Nb as biomaterial is the matter of study of this work regarding wear and corrosion resistances, and the tribocorrosion behavior of this alloy in contact with pH 7, deaerated Hanks solution at 37 °C to simulate a body fuid. All samples have had surface prepared according to the same protocol and a subtract characterization previously and after the electrochemical, dry wear, and tribocorrosion experiments. Results showed high corrosion resistance, with constant open circuit potential (~− 200 mV) and low corrosion current density (~0.9×10−8 A/cm2 ) and important pitting resistance, as well as higher coefcient of friction (COF) for both wear (0.69) and tribocorrosion (0.65) tests than those reported in the literature and, additionally, less wear under tribocorrosion condition compared to dry wear test