Search results for "Matrix"

An inter-laboratory comparison to evaluate the suitability of EN 1787 standard to detect irradiation in plant-origin foods with health benefits

2020

Abstract This paper reports the results of a study carried out to verify the applicability of the EN 1787 method, which uses the Electron Spin Resonance (ESR) technique for the identification of irradiated plant-origin foods with health benefits. The method was tested on samples of herbal ingredients of Plant Food Supplements (PFSs), nuts and fresh blueberries. Untreated and irradiated samples of Camellia sinensis (leaves) Ginkgo biloba (leaves), Glycine max (seeds), Silybum marianum (fruits), Vaccinium myrtillus (fruits), almonds, hazelnuts, peanuts, pistachios, walnuts and fresh blueberries were analysed. The work includes an inter-laboratory blind test involving five Italian laboratories…

Evolution of Cell Adhesion Systems: Evidence for Arg-Gly-Asp-Mediated Adhesion in the Protozoan Neoparamoeba aestuarina

1995

Developmental processes in multicellular organisms require structural elements, such as adhesion molecules, to stabilize cells at functional positions. In vertebrates, a series of extracellular matrix proteins, e.g. fibronectin and laminin, are involved in cell adhesion. These proteins contain Arg-Gly-Asp [RGD] at their binding sites. Here we show that at concentrations above 2 mM the peptide GRGDSPK, comprising the tripeptide RGD (Arg-Gly-Asp), prevents the adhesiveness of cells of the marine amoeba Neoparamoeba aestuarina. In addition, elevated levels of GRGDSPK cause cells to alter their shapes from those with digitiform subpseudopodia to rounded cells with small lobed pseudopodia. These…

Cajal–Retzius and Subplate Cells

2013

The laminar and columnar organization of the mature cerebral cortex is determined by a variety of early developmental processes. Two distinct populations of early generated preplate neurons play key roles in corticogenesis. Cajal–Retzius neurons, located in the marginal zone (later layer I), control the formation of neocortical layers by releasing the extracellular matrix protein reelin, which serves as a guiding signal for migrating neurons. Subplate neurons in the lower neocortical layer play an active role in transient synaptic circuits and influence early cortical plasticity and the maturation of the columnar architecture. Both neuronal cell populations serve as transient synaptic targe…

Pulsed Electric Field Processing Optimization of Ascorbic Acid in a Mango and Papaya Beverage Sweetened with Stevia Rebaudiana

2016

During the processing of liquid foods, ascorbic acid may be altered, thus reducing beneficial health effects. For this reason, the degradation kinetics of ascorbic acid were determined in a fruit juice mixture (papaya and mango) sweetened with Stevia rebaudiana (SR) infusion after treatment by pulsed electric field (PEF) processing. The variable ranges were 20-40 kV/cm (electric field strength, E) during 100-360 μs (time treatment, t). The degradation equation was AA (mg/100 mL) = 26.842 - 0.101·E - 0.003·t- 10.371·%Stevia + 2.865·%Stevia2, demonstrating the use of PEF as an alternative to pasteurization treatments. However, results show the need to optimize treatment conditions whenever th…

Feedback Mechanisms between ?2M and TGF?1 Reduce Extracellular Matrix Synthesis of Liver Fat-Storing Cells

1994

Interaction of aroma compounds with food matrices

2015

Abstract Aroma compounds are volatile molecules which, in order to be perceived, have to be released from the food during the eating process and must reach the olfactory receptors. Their release from the food matrix into the vapour phase highly depends on their interaction with non-volatile compounds present in the food matrix, such as proteins, carbohydrates and lipids. In real food, the complexity of the matrix also needs to take into account the interactions between macromolecules and the structure and microstructure, as well as the in-mouth processing. An example of aroma–matrix interaction in cheeses in relation to perception will be given.

Co-expression and Functional Interaction of Silicatein with Galectin

2006

Sponges (phylum Porifera) of the class of Demospongiae are stabilized by a siliceous skeleton. It is composed of silica needles (spicules), which provide the morphogenetic scaffold of these metazoans. In the center of the spicules there is an axial filament that consists predominantly of silicatein, an enzyme that catalyzes the synthesis of biosilica. By differential display of transcripts we identified additional proteins involved in silica formation. Two genes were isolated from the marine demosponge Suberites domuncula; one codes for a galectin and the other for a fibrillar collagen. The galectin forms aggregates to which silicatein molecules bind. The extent of the silicatein-mediated s…

The Origin of Metazoan Complexity: Porifera as Integrated Animals

2011

SYNOPSIS. Sponges [Porifera] are the phylogenetically oldest metazoan phylum still extant today; they share the closest relationship with the hypothetical common metazoan ancestor, the Urmetazoa. During the past 8 years cDNAs coding for proteins involved in cell-cell- and cell-tissue interaction have been cloned from sponges, primarily from Suberites domuncula and Geodia cydonium and their functions have been studied in vivo as well as in vitro. Also, characteristic elements of the extracellular matrix have been identified and cloned. Those data confirmed that all metazoan phyla originate from one ancestor, the Urmetazoa. The existence of cell adhesion molecules allowed the emergence of a c…

Modulation of Nuclear Matrix-associated 2′,5′-Oligoadenylate Metabolism and Ribonuclease L Activity in H9 Cells by Human Immunodeficiency Virus

1989

Human T cells (H9), infected with the HTLV-IIIB strain of the human immunodeficiency virus (HIV-1), have been used to study the alteration of 2',5'-oligoadenylate [2'-5')A) metabolism in relation to virus production. The synthesis of (2'-5')A was determined to proceed in close association with the nuclear matrix. After HIV infection the (2'-5')A synthetase activity increased from 1.1 to 1.5 pmol of (2'-5')A synthesized/100 micrograms of nuclear matrix protein (during a 3-h in vitro incubation period) to 8.2 pmol at day 3 after infection. Then the activity dropped to the initial values. In non-infected H9 cells the (2'-5')A synthetase activity remained unchanged. Simultaneously with the decr…

DSD-1-Proteoglycan/Phosphacan and Receptor Protein Tyrosine Phosphatase-Beta Isoforms during Development and Regeneration of Neural Tissues

2007

Interactions between neurons and glial cells play important roles in regulating key events of development and regeneration of the CNS. Thus, migrating neurons are partly guided by radial glia to their target, and glial scaffolds direct the growth and directional choice of advancing axons, e.g., at the midline. In the adult, reactive astrocytes and myelin components play a pivotal role in the inhibition of regeneration. The past years have shown that astrocytic functions are mediated on the molecular level by extracellular matrix components, which include various glycoproteins and proteoglycans. One important, developmentally regulated chondroitin sulfate proteoglycan is DSD-1-PG/phosphacan,…