Extracellular Vesicles in Osteosarcoma: Antagonists or Therapeutic Agents?

Osteosarcoma (OS) is a skeletal tumor affecting mainly children and adolescents. The presence of distance metastasis is frequent and it is localized preferentially to the lung, representing the main reason for death among patients. The therapeutic approaches are based on surgery and chemotherapeutics. However, the drug resistance and the side effects associated with the chemotherapy require the identification of new therapeutic approaches. The understanding of the complex biological scenario of the osteosarcoma will open the way for the identification of new targets for its treatment. Recently, a great interest of scientific community is for extracellular vesicles (EVs), that are released in the tumor microenvironment and are important regulators of tumor proliferation and the metastatic process. At the same time, circulating extracellular vesicles can be exploited as diagnostic and prognostic biomarkers, and they can be loaded with drugs as a new therapeutic approach for osteosarcoma patients. Thus, the characterization of OS-related EVs could represent a way to convert these vesicles from antagonists for human health into therapeutic and/or diagnostic agents.     

Combined hydrogen production and power generation from aluminum combustion with water: Analysis of the concept

In this paper the combined production of hydrogen and power based on the aluminum combustion with water is investigated. Furthermore, a concept system is proposed that is potentially able to provide pressurized hydrogen and high temperature steam along with heat and work at the crankshaft. The system demonstrates high energy conversion efficiency, and it fully complies with environment sustainability requirements.     

New insights on the consolidation of salt weathered limestone: the case study of Modica stone

Bulletin of Engineering Geology and the Environment - The deterioration of a stone material is related to its pore structure, which affects the interaction between surface and environmental agents....     

Combustion of fine aluminum and magnesium powders in water

Micron-sized metal powders carried by a nitrogen flow were fed along the axis of a cylindrical hydrogen/oxygen diffusion flame. The particles ignited and burned in the water vapor at approximately 2500 K. Experiments were performed at atmospheric pressure. The environment in which particles burned was characterized in detail using computational fluid dynamics. The computations confirmed that the metal powders burned in water while the effect of oxygen and other oxidizing species could be neglected. Combustion was characterized experimentally for micron-sized powders of both aluminum and magnesium. Particle size distributions were measured using low-angle laser light scattering. Optical emission of the burning particles was recorded using filtered photomultiplier tubes. Measured durations of individual particle emission pulses were assumed to represent their burn times; these data were classified into logarithmically spaced time bins. The distribution of the particle burn times was correlated with their size distributions assuming that larger size particles burned longer. It was observed that correlation between the burn times, t, and particle diameters, D, can be approximately described as t ∼ D^0.64 and t ∼ D^0.68 for aluminum and magnesium powders, respectively. The results were compared to previous reports and possible reasons for discrepancies between the present and earlier results were discussed.     

Identification of large polycyclic aromatic hydrocarbons in carbon particulates formed in a fuel-rich premixed ethylene flame

Large polycyclic aromatic hydrocarbons were identified in carbon particulate sampled in a fuel-rich premixed ethylene flame. The particulate was extracted with dichloromethane (DCM) in order to separate the soluble organic species (DCM-extract) from the solid carbon (soot). After DCM extraction soot was re-extracted with N-methyl pyrrolidone (NMP) obtaining the NMP-extract. Both the DCM-extract and NMP-extract were further fractionated by size exclusion chromatography in selected molecular weight (MW) ranges. Large polycyclic aromatic hydrocarbons obtained by regular incorporation of C₂ and/or C₂H₂ unit (24/26 rule) occurring in both odd and even series of carbon atom number of polycyclic aromatic hydrocarbons, were identified by laser desorption ionization–mass spectrometry (LDI–MS) analysis of the lighter MW fractions of both the DCM-extract and NMP-extract (100–400 u MW of the DCM-extract and 200–600 u fractions of the NMP-extract). The LDI–MS spectra of the heaviest MW fractions of DCM-extract and NMP-extract (600–2000 u and 600–5000 u fraction) showed a continuous spectrum of masses typical of polymeric structures. The UV–visible absorption and emission spectral analysis corroborated the assignment of lighter and of heavier fractions of DCM-extract and NMP-extract to PAH and to polymeric aromatic structures, respectively.     

Effects of high glucose on vascular endothelial growth factor synthesis and secretion in aortic vascular smooth muscle cells from obese and lean zucker rats

Type 1 diabetes is characterized by insulin deficiency, type 2 by both insulin deficiency and insulin resistance: in both conditions, hyperglycaemia is accompanied by an increased cardiovascular risk, due to increased atherosclerotic plaque formation/instabilization and impaired collateral vessel formation. An important factor in these phenomena is the Vascular Endothelial Growth Factor (VEGF), a molecule produced also by Vascular Smooth Muscle Cells (VSMC). We aimed at evaluating the role of high glucose on VEGF-A(164) synthesis and secretion in VSMC from lean insulin-sensitive and obese insulin-resistant Zucker rats (LZR and OZR). In cultured aortic VSMC from LZR and OZR incubated for 24 h with d-glucose (5.5, 15 and 25 mM) or with the osmotic controls l-glucose and mannitol, we measured VEGF-A(164) synthesis (western, blotting) and secretion (western blotting and ELISA). We observed that: (i) d-glucose dose-dependently increases VEGF-A(164) synthesis and secretion in VSMC from LZR and OZR (n = 6, ANOVA p = 0.002-0.0001); (ii) all the effects of 15 and 25 mM d-glucose are attenuated in VSMC from OZR vs. LZR (p = 0.0001); (iii) l-glucose and mannitol reproduce the VEGF-A(164) modulation induced by d-glucose in VSMC from both LZR and OZR. Thus, glucose increases via an osmotic mechanism VEGF synthesis and secretion in VSMC, an effect attenuated in the presence of insulin resistance.     

Study on the applicability of high-pressure homogenization for the production of banana juices

The aim of this preliminary study was to evaluate the potential applicability of high-pressure homogenization (HPH) for the production of banana juices. To this purpose, a prototype equipment working up to 400 MPa and a lab-scale homogenizer working up to 150 MPa were used. Temperature, microbial load, pectate lyase activity, colour and viscosity of the samples homogenized at increasing pressure were evaluated. Pressures higher than 200 MPa were needed to obtain 4 log unit reduction of total mesophilic bacteria and pectate lyase inactivation. Following HPH, banana juice resulted brighter and less viscous than the untreated one. Data suggest that HPH treatments could be a reliable technological alternative to conventional heat treatments for the production of added-value fruit juices. However, the homogenization design could play a critical role in affecting the product quality attributes. In fact, homogenization performed at the same operative pressure by using different equipment leads to different effects on product quality.     

Emulsification of Simulated Gastric Fluids Protects Wheat α-Amylase Inhibitor 0.19 Epitopes from Digestion

Wheat α-amylase inhibitors (α-AIs) are known anti-nutritional factors, respiratory allergens, and they can sporadically cause food allergy. α-AIs are therefore expected to reach the enteric mucosae in an immunologically active form, but information on their stability to gastric digestion is not available. Resistance to pepsinolysis is nonetheless a key factor for any food allergen. We therefore investigated whether α-AIs could resist pepsin digestion in simulated gastric fluids (SGF) and in emulsified SGF, the latter simulating more realistically the multi-phase nature of stomach bolus. Since α-AIs comprise a huge family of proteins, we investigated 0.19 α-AI as a prominent member. The digestion patterns were analyzed by immunoblotting using anti-0.19 polyclonal antibodies and sera from wheat allergic patients sensitized to 0.19 α-AI. The results show that the immune epitopes of α-AI are detectable up to 120 min of digestion in emulsifying conditions. Intra-molecular disulfide bonds and, in particular, emulsification were found to be crucial factors for protein stability. The results show that 0.19 α-AI must be considered a potential food allergen.     

Evidence for the existence of a specific g protein-coupled receptor activated by guanosine

Guanosine, released extracellularly from neurons and glial cells, plays important roles in the central nervous system, including neuroprotection. The innovative DELFIA Eu‐GTP binding assay was optimized for characterization of the putative guanosine receptor binding site at rat brain membranes by using a series of novel and known guanosine derivatives. These nucleosides were prepared by modifying the purine and sugar moieties of guanosine at the 6‐ and 5′‐positions, respectively. Results of these experiments prove that guanosine, 6‐thioguanosine, and their derivatives activate a G protein‐coupled receptor that is different from the well‐characterized adenosine receptors.     

Neuropeptide S receptor: recent updates on nonpeptide antagonist discovery

Neuropeptide?S (NPS) is a 20-amino acid peptide of great interest due to its possible involvement in several biological processes, including food intake, locomotion, wakefulness, arousal, and anxiety. Structure-activity relationship studies of NPS have identified key points for structural modifications with the goal of modulating NPS receptor (NPSR) agonist activity or achieving antagonism at the same receptor. Only limited information is available for nonpeptide NPSR antagonists. In the last year, several studies have been reported in literature which present various series of small molecules as antagonists of this receptor. The results allow a comparison of the structures and activities of these molecules, leading to the design of new ligands with increased potency and improved pharmacological and pharmacokinetic profiles. This work presents a brief overview of the available information regarding structural features and pharmacological characterization of published nonpeptide NPSR antagonists.