Mechanism of in vitro heme-induced LDL oxidation: effects of antioxidants

BACKGROUND: Heme protein toxicity, owing to generation of reactive oxygen species most likely by direct interaction between heme iron and hydrogen peroxide (H2O2), may be involved in various pathologies, including atherogenesis and pigmentary acute renal failure. The aim of this study was to investigate the mechanism of heme cytotoxicity and the effects of antioxidant therapies in an in vitro model of heme-induced low-density lipoprotein (LDL) oxidation. MATERIALS AND METHODS: Human LDLs were exposed to heme, iron (Fe), protoporphyrin (PPIX) and PPIX-Zinc (Zn) with or without H2O2. Lipid peroxidation was monitored by measurement of conjugated diene formation (at the 234-nm absorbance). The effect of various antioxidants, such as vitamin E and vitamin C, reduced glutathione (GSH), and oxidized glutathione (GSSG), mannitol and desferoxamine (DFO) was further investigated in the established in vitro model of LDL oxidation. RESULTS: Incubation of LDLs in the presence of heme/H2O2 induced lipid peroxidation with the optimal oxidation rate being at 5 microm heme/100 microm H2O2 doses. By contrast, incubation of LDL with H2O2, Fe, Fe/H2O2, PPIX, PPIX/H2O2, heme or PPIX-Zn did not initiate any LDL oxidation. In vitro, the vitamin E load protected native LDLs against heme/H2O2 oxidative modifications. Incubation of LDLs with increasing doses of vitamin C, GSH and DFO conferred a dose-dependent protection, while mannitol and GSSG had no effect. CONCLUSIONS: Initiation and propagation of heme-induced lipid peroxidation is not mediated by a Fenton reaction but depends on specific interactions between heme and H2O2. It may result from the generation of ferryl and perferryl radicals derived from hemic Fe and H2O2 interactions. A protective effect of vitamins E, C, GSH and DFO was demonstrated in this model.     

Prospective evaluation of a clinical guideline recommending early patients discharge in bleeding peptic ulcer

Background and Aim: To validate an early discharge policy in patients admitted with upper gastrointestinal bleeding (UGIB) due to ulcers. Methods: Patients with gastroduodenal ulcer or erosive gastritis/duodenitis were included in a previous study aiming to develop a practice guideline for early discharge of patients with UGIB. Variables associated with unfavorable evolution were analyzed in order to identify patients with low‐risk of re‐bleeding. After that, a one‐year prospective analysis of all UGIB episodes was carried out. Results: A total of 341 patients were identified in the retrospective study. Variables associated with unfavorable evolution were: systolic blood pressure ≤ 100 mmHg, heart rate ≥ 100 bpm, and a Forrest endoscopic classification of severe. 10% of patients were immediately discharged; however, if predictive variables obtained in the multivariate analysis had been used, hospitalization could have been prevented in 34% of patients. A total of 77 patients were included in the prospective analysis. Although only 19.5% of patients were immediately discharged without complications, 29 patients (37.7%) were theoretically suitable for early discharge. Conclusions: Patients with UGIB who have clean‐based ulcers and are stable on admission can be safely discharged immediately after endoscopy. Implementation of the clinical practice guideline safely reduced hospital admission for those patients.     

Phenomenon of new drugs on the Internet: the case of ketamine derivative methoxetamine

On the basis of the material available both in the scientific literature and on the web, this paper aims to provide a pharmacological, chemical and behavioural overview of the novel compound methoxetamine. This is a dissociative drug related to ketamine, with a much longer duration of action and intensity of effects. A critical discussion of the availability of information on the web of methoxetamine as a new recreational trend is here provided. Those methodological limitations, which are intrinsically associated with the analysis of online, non-peer reviewed, material, are here discussed as well. It is concluded that the online availability of information on novel psychoactive drugs, such as methoxethanine, may constitute a pressing public health challenge. Better international collaboration levels and novel forms of intervention are necessary to tackle this fast-growing phenomenon.     

In vitro and in vivo evaluation of acellular diaphragmatic matrices seeded with muscle precursors cells and coated with VEGF silica gels to repair muscle defect of the diaphragm

In this work, a bioartificial system consisting of VEGF-loaded porous silica gel and myoblasts cultured on acellular diaphragmatic matrix (ADM) has been implanted to repair a surgically created diaphragmatic defect in Lewis rats. ADMs exerted a strong angiogenic response on chorio-allantoic membrane. Cytotoxicity, VEGF release and matrix erodibility in vitro tests demonstrated that the silica support was nontoxic and that the VEGF bioactivity was maintained after matrix entrapment and it was released within a timeframe that can be modulated by synthesis parameters. Different grafts composed by ADMs with and without autologous male myoblasts or/and VEGF-loaded porous silica gel have been implanted to repair previously created diaphragmatic defects in female Lewis rats. Patches composed of ADMs and myoblasts appeared well preserved until 8 weeks, and contained multinucleated cells and cholinergic fibers. At 8 weeks, the implanted cells were still present inside the patches. The disappointing results obtained when VEGF was delivered by porous silica gel were probably due to an abnormal angiogenic response following an excess of local growth factor concentration. Taken together, these results confirmed that our matrices contained biologically active angiogenic factors which were per se sufficient to induce neo-vessels formation, thus allowing the survival of implanted myoblasts.     

Patients' desire to preserve sexual activity and final decision for a nerve-sparing approach: results from the MIRROR (Multicenter Italian Report on Radical Prostatectomy Outcomes and Research) Study

IntroductionPreservation of sexual function after surgery represents a major issue for patients undergoing radical prostatectomy (RP).AimTo investigate determinants of patients’ desire to preserve sexual activity before RP and surgeons’ final decision to perform a nerve-sparing RP (NSRP).MethodsOverall, 2,408 prostate cancer patients, candidates to RP, from 136 urologic departments across the Italian territory were evaluated in a multicenter prospective observational study. All patients underwent RP, according to single-center indications and procedures.Main Outcome MeasuresAge, body mass index, previous benign prostatic hyperplasia history, preoperative tumor characteristics, quality of life through the Short Form Health Survey (SF-12), and the University of California Los Angeles Prostate Cancer Index (UCLA-PCI), erectile function through the International Index of Erectile Function (IIEF-5), desire to preserve sexual activity, NS operative outcomes, and surgical margins status were recorded.ResultsOverall, 1,667 were interested to preserve sexual activity. Age, physical component summary of SF12 (PCS-12), sexual function score of UCLA-PCI, and IIEF-5 score were the main determinants of such interest. Only 1,246 patients were suitable for a NSRP according to guidelines. Surgeons performed a non-NSRP (NNSRP) in 1,234 patients, a unilateral NSRP in 318 and a bilateral NSRP in 856. Age, bioptical Gleason score, percentage of positive cores, PCS-12, and patient's desire to preserve sexual activity were the main determinants of final decision for a NSRP. Surgeons performed a NSRP in 424 not suitable and in 121 not interested patients. Positive surgical margins in not suitable patients submitted to NSRP were not higher if compared to that obtained after NNSRP in the same subgroup. Limits include lack of oncological and functional follow-up.ConclusionsMost patients are interested to preserve sexual activity. Discrepancies exist among patients’ preferences, guidelines’ indications, and surgeon's final decision. Imbimbo C, Creta M, Gacci M, Simonato A, Gontero P, de Cobelli O, Briganti A, Fulcoli V, Martorana G, Nicita G, Mirone V, and Carmignani G. Patients’ desire to preserve sexual activity and final decision for a nerve-sparing approach: results from the M.I.R.R.O.R. (Multicenter Italian Report on Radical prostatectomy Outcomes and Research) study.     

Reversine, a novel Aurora kinases inhibitor, inhibits colony formation of human acute myeloid leukemia cells

The demonstration that the small synthetic molecule reversine [2-(4-morpholinoanilino)-N6-cyclohexyladenine] promotes the dedifferentiation of committed cells into multipotent progenitor-type cells has raised hopes on the exploitation of this small chemical tool for the generation of stem cells. Here, we show that reversine causes a failure in cytokinesis and induces polyploidization. These effects of reversine are due to the inhibition of Aurora A and B, two related kinases that are implicated in several aspects of mitosis and that are frequently amplified and overexpressed in human tumors. Reversine inhibits the phosphorylation of histone H3, a direct downstream target of Aurora kinases. Similarly to the Aurora kinase inhibitor VX-680, which has recently entered phase II clinical trials for cancer treatment, reversine inhibited colony formation of leukemic cells from patients with acute myeloid leukemia but was significantly less toxic than VX-680 on cells from healthy donors. The crystal structure of the reversine-Aurora B kinase complex shows that reversine is a novel class of ATP-competitive Aurora kinase inhibitors. Thus, although our studies raise serious doubts on the application of reversine in regenerative medicine, they support the paradigm that reversine might be a useful agent in cancer chemotherapy.     

Clinical Management of COPD in a Real-World Setting. A Big Data Analysis

ObjectiveThe aim of this study was to evaluate the quality of diagnosis and treatment of COPD using Big Data methodology on the Savana Manager 2.1 clinical platform.Materials and methodsA total of 59,369 patients with a diagnosis of COPD were included from a population of 1,219,749 adults over 40 years of age.ResultsIn total, 78% were men. Spirometry data were available for only 26,453 (43.5%) subjects. Disease severity was classified in 18,172 patients: 4396 mild, 7100 moderate, and 6676 severe, although only 27%, 34%, and 28%, respectively, presented obstructive spirometry. The clinical management of COPD is mainly the responsibility of the primary care and pulmonology departments, while internal medicine and, to a lesser extent, geriatrics also participate. Drug treatment was based on bronchodilators and inhaled corticosteroids (ICS). A marked decline in the use of long-acting beta-2 agonists (LABA) in monotherapy and a slight reduction in ICS/LABA combinations, associated with a long-acting anticholinergic (LAMA) in 74% of cases, were observed. All-cause in-hospital mortality among the overall population was 5.6% compared to 1% of the general population older than 40 years. In total, 35% were admitted to hospital, with an average stay of 6.6 days and an in-hospital mortality rate in this group of 10.74%.DiscussionThis study identifies the main features of an unselected COPD population and the main errors made in the management of the disease.