Thermodynamic Field Theory with the Iso-Entropic Formalism

A new formulation of the thermodynamic field theory (TFT) is presented. In this new version, one of the basic restriction in the old theory, namely a closed-form solution for the thermodynamic field strength, has been removed. In addition, the general covariance principle is replaced by Prigogine's thermodynamic covariance principle (TCP). The introduction of TCP required the application of an appropriate mathematical formalism, which has been referred to as the iso-entropic formalism. The validity of the Glansdorff-Prigogine Universal Criterion of Evolution, via geometrical arguments, is proven. A new set of thermodynamic field equations, able to determine the nonlinear corrections to the linear ("Onsager") transport coefficients, is also derived. The geometry of the thermodynamic space is non-Riemannian tending to be Riemannian for hight values of the entropy production. In this limit, we obtain again the same thermodynamic field equations found by the old theory. Applications of the theory, such as transport in magnetically confined plasmas, materials submitted to temperature and electric potential gradients or to unimolecular triangular chemical reactions can be found at references cited herein.Comment: 35 page

Further studies on the gangliosidic nature of the cholinergic-specific antigen, Chol-1.

The antigen designated as Chol-1 beta, detected by an antiserum specific for cholinergic neurons, has been purified to homogeneity from ganglioside mixtures extracted from Torpedo electric organ and pig brain. The final products from the two sources behaved identically in a wide range of tests and gave coincident immunopositive and Ehrlich-positive spots after thin layer chromatography in seven different solvent systems; they were thus considered to be identical and to constitute a single, pure chemical species. Gas-chromatographic analysis revealed the presence of long-chain bases, glucose, galactose, N-acetylgalactosamine, and sialic acid in integral molar ratios of 1:1:2:1:3; the compound's reactivity to cholera toxin after Vibrio cholerae sialidase treatment on thin layer chromatography and the recovery of GM1 as sole product of exhaustive sialidase treatment identified it as a member of the gangliotetrahexosyl series. From the products of partial enzymatic desialylation and treatment with beta-galactosidase and a comparison of the compound's immunoreactivity to anti-Chol-1 antisera with that of other trisialogangliosides of defined molecular structure, we were able to assign a disialosyl residue alpha-Neu5Ac-(2----8)-alpha-Neu5Ac-(2----3)- to the inner galactose, and we suggest GalNAc as a possible site of linkage of the third sialic acid

Sphingolipids and neuronal degeneration in lysosomal storage disorders

Ceramide, sphingomyelin, and glycosphingolipids (both neutral and acidic) are characterized by the presence in the lipid moiety of an aliphatic base known as sphingosine. Altogether, they are called sphingolipids and are particularly abundant in neuronal plasma membranes, where, via interactions with the other membrane lipids and membrane proteins, they play a specific role in modulating the cell signaling processes. The metabolic pathways determining the plasma membrane sphingolipid composition are thus the key point for functional changes of the cell properties. Unnatural changes of the neuronal properties are observed in sphingolipidoses, lysosomal storage diseases occurring when a lysosomal sphingolipid hydrolase is not working, leading to the accumulation of the substrate and to its distribution to all the cell membranes interacting with lysosomes. Moreover, secondary accumulation of sphingolipids is a common trait of other lysosomal storage diseases

Preparation of deacetyl-, lyso-, and deacetyl-lyso-GM3 by selective alkaline hydrolysis of GM3 ganglioside

Abstract Three methods (using GM3 quantities ranging from a few milligrams to grams) have been developed to prepare, in high yield, the three derivatives of ganglioside GM3 [α-Neu5Ac-(2-3)-β-Gal-(1-4)-β-Glc-(1-1)-ceramide]: deacetyl-GM3 [α-Neu-(2-3)-β-Gal-(1-4)-β-Glc-(1-1)-ceramide], lyso-GM3 [α-Neu5Ac-(2-3)-β-Gal-(1-4)-β-Glc-(1-1)-sphingosine], and deacetyl-lyso-GM3 [α-Neu-(2-3)-β-Gal-(1-4)-β-Glc-(1-1)-sphingosine]. This is the first report of the preparation of lyso-GM3 by a one-pot reaction. We can now define the optimal conditions for the different preparations. Preparation of deacetyl-GM3: alkaline reagent, 2 M KOH in water; GM3 concentration, 33 mg/ml; reaction temperature, 90 °C; reaction time, 3.5 h; nitrogen atmosphere. Preparation of deacetyl-lyso-GM3: alkaline reagent, 8 M KOH in water; GM3 concentration, 10 mg/ml; reaction temperature, 90 °C; reaction time, 18 h; nitrogen atmosphere. Preparation of lyso-GM3: alkaline reagent, 1 M sodium tert-butoxide in methanol; GM3 concentration, 10 mg/ml; reaction temperature, 80 °C; reaction time, 18 h; anhydrous conditions. The percentage yield of deacetyl-GM3 was 70–75%, that of deacetyl-lyso-GM3 100%, and of lyso-GM3 36–40%. Deacetyl-GM3, deacetyl-lyso-GM3, and lyso-GM3 were purified by column chromatography, and chemical structures were confirmed by electron spray-mass spectrometry. —Valiente, O., L. Mauri, R. Casellato, L. E. Fernandez, and S. Sonnino. Preparation of deacetyl-, lyso-, and deacetyl-lyso-GM3 by selective alkaline hydrolysis of GM3 ganglioside

GM1 Ganglioside Is A Key Factor in Maintaining the Mammalian Neuronal Functions Avoiding Neurodegeneration

Many species of ganglioside GM1, differing for the sialic acid and ceramide content, have been characterized and their physico\u2010chemical properties have been studied in detail since 1963. Scientists were immediately attracted to the GM1 molecule and have carried on an ever\u2010increasing number of studies to understand its binding properties and its neurotrophic and neuroprotective role. GM1 displays a well balanced amphiphilic behavior that allows to establish strong both hydrophobic and hydrophilic interactions. The peculiar structure of GM1 reduces the fluidity of the plasma membrane which implies a retention and enrichment of the ganglioside in specific membrane domains called lipid rafts. The dynamism of the GM1 oligosaccharide head allows it to assume different conformations and, in this way, to interact through hydrogen or ionic bonds with a wide range of membrane receptors as well as with extracellular ligands. After more than 60 years of studies, it is a milestone that GM1 is one of the main actors in determining the neuronal functions that allows humans to have an intellectual life. The progressive reduction of its biosynthesis along the lifespan is being considered as one of the causes underlying neuronal loss in aged people and severe neuronal decline in neurodegenerative diseases. In this review, we report on the main knowledge on ganglioside GM1, with an emphasis on the recent discoveries about its bioactive component

Characterization of the GM1 oligosaccharide transport across the blood-brain-barrier

Ganglioside GM1 has demonstrated to attenuate Parkinson Disease (PD) symptoms in clinical and preclinical trials. Nevertheless, the GM1 efficacy revealed in vitro is critically reduced in vivo, because of the amphiphilic behavior that limits the passage across the blood brain barrier (BBB). In vitro and in vivo experiments showed that GM1 exerts neurotrophic functions by interacting with plasma membrane (PM) proteins throughout its oligosaccharide portion (OligoGM1). Furthermore, OligoGM1 intravenously or subcutaneously injected into mice is absorbed and taken up by different organs and tissues, including brain. In order to take advantage of GM1 oligosaccharide properties and to overcome GM1 pharmacological limitation, this study has been aimed by the investigation of the OligoGM1 transportthrough the BBB, by using a human in vitro model for human brain-like endothelial cells (hBLEC). Ruled out the toxicity of OligoGM1 on hBLEC, the OligoGM1 transport across the hBBB has been analyzed, finding out a 20 fold higher rate than GM1 and a time and concentration dependence. In order to characterize the OligoGM1 passage, a direct evaluation of the OligoGM1 interaction with the ABC-transporters was carried on, leaving out this way for OligoGM1 transport. Moreover, inverse- and 4\ub0C-transport experiments were performed excluding the implication of the active transport for OligoGM1 passage across the hBLEC, leading to consider the passive-paracellular route. Furthermore, after the hBLEC transport, OligoGM1 maintained its stability and capacity to induce neuritogenesis in the mouse neuroblastoma cells line Neuro2a. This preliminary study has improved the knowledge about the GM1 pharmacological potential by proving that OligoGM1 can cross advantageously the BBB, offering a new promising therapeutic strategy

Balancing competing policy demands: the case of sustainable public sector food procurement.

A focus on market-based green growth strategies to pursue sustainability goals neglects the pursuit of understanding how human health is interwoven with the health of eco-systems to deliver sustainability goals. The article argues that clarifying the difference between green and sustainable public sector food procurement, with political continuity that supports and enables policymakers and practitioners to take an incremental approach to change, makes an important contribution to delivering more sustainable food systems and better public health nutrition. Five European case studies demonstrate the reality of devising and implementing innovative approaches to sustainable public sector food procurement and the effects of cultural and political framings. How legislation is enacted at the national level and interpreted at the local level is a key driver for sustainable procurement. Transition is dependent on political will and leadership and an infrastructure that can balance the economic, environmental and social drivers to effect change. The development of systems and indicators to measure change, reforms to EU directives on procurement, and the relationship between green growth strategies and sustainable diets are also discussed. The findings show the need to explore how consistent definitions for green public procurement and sustainable public procurement can be refined and standardized in order to support governments at all levels in reviewing and analyzing their current food procurement strategies and practices to improve sustainability

Characterization of a glycosphingolipid antigen defined by the monoclonal antibody MBr1 expressed in normal and neoplastic epithelial cells of human mammary gland

The antigen defined by a monoclonal antibody, MBr1, was found to be expressed in normal human mammary gland epithelia and human mammary carcinoma cells (Menard, S., Tagliabue, E., Canevari, S., Fossati, G., and Colnaghi, M. I. (1983) Cancer Res. 43, 1295-1300). The antigen has been isolated from breast cancer cell line MCF-7, which was used as immunogen, and its structure was determined by methylation analysis, NMR spectroscopy, direct probe mass spectrometry, and enzymatic degradation as identified below. Fuc alpha 1----2Gal beta 1----3GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1Cer The antibody cross-reacted weakly with fucosylasialo-GM1 (IV2FucGg4), which shares the same terminal sequence, Fuc alpha 1----2Gal beta 1----3GalNAc, with this antigen. However, various other structures, including lacto-series H structure (Fuc alpha 1----2 Gal beta 1----4/or 3GlcNAc beta 1----3Gal), did not show any reactivity with this antibody. Therefore, this antigen represents a blood group H antigen with a globo-series structure which is abundant in human teratocarcinoma (Kannagi, R., Levery, S. B., Ishigami, F., Hakomori, S., Shevinsky, L. H., Knowles, B. B., and Solter, D. (1983) J. Biol. Chem. 258, 8934-8942), although its presence must be limited in normal adult human tissue

Cold preservation of the human colon and ileum with University of Wisconsin solution

The inclusion of the colon in the intestinal graft resulted in worsening patient and graft outcome and increased the incidence of infection and rejection. In this study, we examine the role of ischemia on the barrier function of the epithelium during cold ischemia. Samples were collected from 15 harvested and transplanted human donor grafts (colon, 10; ileum, 6), which were immersed in University of Wisconsin (UW) solution. Ischemia (6, 12, 24, and 45 h) and reoxygenation were performed to evaluate the mucosal electrical status using the Ussing chamber technique. The functions of enterocytes and crypt cells were tested by glucose and theophylline challenge. Modified Park's classification was applied to evaluate the severity of mucosal damage under light microscopy. The colon had higher levels of baseline potential difference, short-circuit current, and resistance than the ileum during 6-48 h of ischemia. Colonic epithelial cells responded well to theophylline stimulation at 24 h of ischemia, while there was no ileal response. The colonic mucosa was histopathologically well preserved in UW solution for 48 h, and mucosal damage induced by reoxygenation was less than in the ileum. In conclusion, electrophysiologically and histopathologically, the colon is less susceptible to cold preservation damage than the ileum during storage with UW solution