Transport and Metabolism at Blood–Brain Interfaces and in Neural Cells: Relevance to Bilirubin-Induced Encephalopathy

Bilirubin, the end-product of heme catabolism, circulates in non-pathological plasma mostly as a protein-bound species. When bilirubin concentration builds up, the free fraction of the molecule increases. Unbound bilirubin then diffuses across blood–brain interfaces (BBIs) into the brain, where it accumulates and exerts neurotoxic effects. In this classical view of bilirubin neurotoxicity, BBIs act merely as structural barriers impeding the penetration of the pigment-bound carrier protein, and neural cells are considered as passive targets of its toxicity. Yet, the role of BBIs in the occurrence of bilirubin encephalopathy appears more complex than being simple barriers to the diffusion of bilirubin, and neural cells such as astrocytes and neurons can play an active role in controlling the balance between the neuroprotective and neurotoxic effects of bilirubin. This article reviews the emerging in vivo and in vitro data showing that transport and metabolic detoxification mechanisms at the blood–brain and blood–cerebrospinal fluid barriers may modulate bilirubin flux across both cellular interfaces, and that these protective functions can be affected in chronic unconjugated hyperbilirubinemia. Then the in vivo and in vitro arguments in favor of the physiological antioxidant function of intracerebral bilirubin are presented, as well as the potential role of transporters such as ABCC1 and metabolizing enzymes such as cytochromes P-450 in setting the cerebral cell- and structure-specific toxicity of bilirubin following hyperbilirubinemia. The relevance of these data to the pathophysiology of bilirubin-induced neurological diseases is discussed

Colonia y nación en la prensa francesa

La prensa francesa entre 1879 y 1914 fue el testigo del auge del colonialismo y del nacionalismo. Las publicaciones impresas sirvieron como altavoz de los partidarios del imperio colonial y publicitó otras formas de propaganda, como la realizada a través de la educación o las exposiciones coloniales. Sin embargo, los periódicos también contribuyeron a conocer los problemas de las colonias y a crear un incipiente anticolonialismo que llegaría a su cénit a mediados del siglo XX. El presente trabajo busca las claves de la relación entre colonia y nación y la huella de este vínculo en la prensa de la época, a través del análisis cualitativo de los artículos publicados en los diarios franceses Le Figaro, La Justice y L’Humanité

Decomposition of two types of electric wires considering the effect of the metal in the production of pollutants

Combustion runs at 700 °C in a horizontal laboratory furnace were carried out on two different electric wires (PVC and halogen-free wire). Tests were performed in the presence and in the absence of the metal conductor of the wires. The analyses of the polycyclic aromatic hydrocarbons (PAHs), chlorobenzenes (CBzs), chlorophenols (CPhs), mono- to octa-chlorodibenzo-p-dioxin and dibenzofurans (PCDD/Fs), and dioxin-like PCBs are shown. Regarding semivolatile compounds, PAHs production decreases in the presence of metal, while a higher amount of chlorinated compounds are emitted. Respect to the PCDD/Fs, the PVC wire in the presence of metal presents the highest emission, with a much more emission of furans than dioxins. The maximum emission is with 2 or 3 chlorine atom PCDD/Fs. PCBs emission correlates with PCDD/F production and represents 3–4% of total toxicity, determined by using WHO2005 factors.Support for this work was provided by the Generalitat Valenciana (Spain) with Projects PROMETEO/2009/043/FEDER, and by the Spanish MCT CTQ2008-05520

Pollutant Formation During the Thermal Decomposition of Electrical and Electronic Wastes

Paper submitted to the 7th International Symposium on Feedstock Recycling of Polymeric Materials (7th ISFR 2013), New Delhi, India, 23-26 October 2013.In this contribution we present the results of the research done at the University of Alicante in the last four years [1-7] about the thermal decomposition of waste electrical and electronic equipment (WEEE). Several materials have been studied, including PVC and halogen-free wires, printed circuit boards and casing from mobile phones, as well as brominated flame reatardants used in the EEE preparation such as TBBPA (tetra-bromo-bisphenol-A). Several experiments were performed in a nitrogen atmosphere (pyrolysis runs) and also in an oxidative atmosphere with different oxygen concentrations. Thermogravimetric runs were used to characterize samples, and a horizontal laboratory reactor was used to study the formation and destruction of pollutants during the thermal decomposition of these samples. More than 150 compounds, including carbon oxides, light hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), chlorophenols (ClPhs), chlorobenzenes (ClBzs) and bromophenols (BrPhs) have been identified and quantified. Furthermore, polychlorodibenzo-p-dioxin and polychlorodibenzofurans (PCDD/Fs), polybromodibenzo-p-dioxin and polybromodibenzofurans (PBDD/Fs), and dioxin-like PCBs produced were analyzed.Generalitat Valenciana: PROMETEO/2009/043/FEDER. Ministerio de Educación y Ciencia: CTQ2008-05520

Thermogravimetric study of the decomposition of printed circuit boards from mobile phones

Thermal decomposition of printed circuits boards (PCB) is studied, using thermogravimetric analysis to compare the thermal behavior of PCB of mobile phones before and after the removal of the metallic fraction by acid washing. Several dynamic and dynamic + isothermal runs have been carried out at different heating rates (5, 10 and 20 K min−1), from room temperature to more than 1100 K. Also runs in the presence and in the absence of oxygen were performed (combustion and pyrolysis runs). Moreover, TG–MS experiments were performed (both in inert and oxidizing atmosphere) in order to better understand the thermal decomposition of these wastes and identify some compounds emitted during the controlled heating of these materials. Different reaction models are proposed, one for pyrolysis and one for combustion of the two kinds of wastes studied, which proved to simulate appropriately the experimental results at all the heating rates simultaneously.Support for this work was provided by the Generalitat Valenciana (Spain), research project Prometeo/2009/043/FEDER, and by the Spanish MCT, research project CTQ2008-05520

Thermal Decomposition of Mobile Phones

Paper submitted to the 31st International Symposium on Halogenated Persistent Organic Compounds (Dioxin 2011), Brussels, Belgium, 21-25 August 2011.Mobile phones are used for a variety of purposes, including keeping in touch with family members, conducting business, and having access to a telephone in the event of an emergency. Some people carry more than one cell phone for different purposes. In 2006 more than one billion mobile phones were shipped worldwide, 22.5 % more than the quantity shipped in 2005. By 2008 the number of mobile phone users around the world was predicted to reach two billion.Support for this work was provided by the Generalitat Valenciana (Spain) with projects Prometeo/2009/043/FEDER and ACOMP2011/224, and by the Spanish MCT CTQ2008-05520

Astrocytic IL-6 Influences the Clinical Symptoms of EAE in Mice

Interleukin-6 (IL-6) is a multifunctional cytokine that not only plays major roles in the immune system, but also serves as a coordinator between the nervous and endocrine systems. IL-6 is produced in multiple cell types in the CNS, and in turn, many cells respond to it. It is therefore important to ascertain which cell type is the key responder to IL-6 during both physiological and pathological conditions. In order to test the role of astrocytic IL-6 in neuroinflammation, we studied an extensively-used animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), in mice with an IL-6 deficiency in astrocytes (Ast-IL-6 KO). Results indicate that lack of astrocytic IL-6 did not cause major changes in EAE symptomatology. However, a delay in the onset of clinical signs was observed in Ast-IL-6 KO females, with fewer inflammatory infiltrates and decreased demyelination and some alterations in gliosis and vasogenesis, compared to floxed mice. These results suggest that astrocyte-secreted IL-6 has some roles in EAE pathogenesis, at least in females

Analysis of the Part Distortions for Inconel 718 SLM: A Case Study on the NIST Test Artifact

The present paper evaluates the misalignment and geometry distortion of the standard National Institute of Standards and Technology (NIST) test artifact in Inconel 718 alloy, when several layers with and without supports are employed to manufacture it by the Selective Laser Melting (SLM) process. To this end, a coordinate-measuring machine (CMM) is used to measure the geometrical distortion in each manufacturing configuration, following the same measurement protocol. The results show that the laser path strategy favors a thermal gradient which, consequently, induces geometrical distortions in the part. To prove this hypothesis, a numerical simulation is performed to determine the thermal gradient and the pattern of the residual stresses. It was found that the geometrical distortion certainly depends on the position of the feature position and laser strategy, where thermal cycles and residual thermal stresses had an impact in the end-part geometry, especially if a high strength-to-weight ratio commonly used in aeronautics is present.This work is supported by the Serra Húnter program (Generalitat de Catalunya) reference number [UPC-LE-304 (2018)] and by the Aeronautics Advanced Manufacturing Center (CFAA) in the JANO—Joint action toward digital transformation project framework. Diego Celentano acknowledges Pontificia Universidad Católica de Chile (PUC), Wallonie-Bruxelles International (WBI) and National Council for Scientific and Technological Research CONICYT (FONDECYT Projects No. 3180006 and 1180591) for the financial supports provided for this work

Vascular network expansion, integrity of blood–brain interfaces, and cerebrospinal fluid cytokine concentration during postnatal development in the normal and jaundiced rat

Background: Severe neonatal jaundice resulting from elevated levels of unconjugated bilirubin in the blood induces dramatic neurological impairment. Central oxidative stress and an inflammatory response have been associated with the pathophysiological mechanism. Cells forming the blood–brain barrier and the choroidal blood–CSF barrier are the first CNS cells exposed to increased plasma levels of unconjugated bilirubin. These barriers are key regulators of brain homeostasis and require active oxidative metabolism to fulfill their protective functions. The choroid plexus-CSF system is involved in neuroinflammatory processes. In this paper, we address the impact of neonatal hyperbilirubinemia on some aspects of brain barriers. We describe physiological changes in the neurovascular network, blood–brain/CSF barriers integrities, and CSF cytokine levels during the postnatal period in normobilirubinemic animals, and analyze these parameters in parallel in Gunn rats that are deficient in bilirubin catabolism and develop postnatal hyperbilirubinemia.// Methods: Gunn rats bearing a mutation in UGT1a genes were used. The neurovascular network was analyzed by immunofluorescence stereomicroscopy. The integrity of the barriers was evaluated by [14C]-sucrose permeability measurement. CSF cytokine levels were measured by multiplex immunoassay. The choroid plexus-CSF system response to an inflammatory challenge was assessed by enumerating CSF leukocytes.// Results: In normobilirubinemic animals, the neurovascular network expands postnatally and displays stage-specific regional variations in its complexity. Network expansion is not affected by hyperbilirubinemia. Permeability of the blood–brain and blood–CSF barriers to sucrose decreases between one- and 9-day-old animals, and does not differ between normobilirubinemic and hyperbilirubinemic rats. Cytokine profiles differ between CSF and plasma in all 1-, 9-, and 18-day-old animals. The CSF cytokine profile in 1-day-old animals is markedly different from that established in older animals. Hyperbilirubinemia perturbs these cytokine profiles only to a very limited extent, and reduces CSF immune cell infiltration triggered by systemic exposure to a bacterial lipopeptide.// Conclusion: The data highlight developmental specificities of the blood–brain barrier organization and of CSF cytokine content. They also indicate that a direct effect of bilirubin on the vascular system organization, brain barriers morphological integrity, and inflammatory response of the choroid plexus-CSF system is not involved in the alteration of brain functions induced by severe neonatal jaundice./