Search results for "polysaccharide"
showing 10 items of 635 documents
Identification of Leguminosae gums and evaluation of carob-guar mixtures by capillary zone electrophoresis of protein extracts.
2002
A procedure for the extraction and capillary zone electrophoresis (CZE) separation of proteins from carob, guar and tara gums in a background electrolyte (BGE) of pH 9 containing 0.1% polyvinyl alcohol is described. The CZE protein profiles exhibit characteristic peaks for each one of the Leguminosae gums, which can be used to construct models capable of identifying samples of carob, guar and tara gums, and predicting the guar content in binary carob-guar mixtures of different geographical origin and harvested in different years. The classification and prediction models are constructed by using linear discriminant analysis (LDA) and multiple linear regression (MLR), respectively. An excelle…
Coexpression of inducible NO synthase and soluble guanylyl cyclase in colonic enterocytes: a pathophysiologic signaling pathway for the initiation of…
1998
Infectious diarrhea is often caused by the exotoxins of gram-negative bacteria such as Escherichia coli. However, these organisms also contain lipopolysaccharide (LPS) endotoxin. LPS induces nitric oxide synthase II (NOS II, inducible NOS) in various types of cells. We now demonstrate by RNase protection analysis, Western blot, and immunohistochemistry that the expression of NOS II mRNA and protein is markedly induced in colonic enterocytes of mice that ingest LPS with their drinking water. Using the same techniques, significant levels of soluble guanylyl cyclase (GC-S), the effector enzyme of NO, were found constitutively expressed in the mucosa. This creates a pathophysiologic autocrine p…
Characterization of a new natural fiber from Arundo donax L. as potential reinforcement of polymer composites.
2013
Abstract The aim of this paper is to study the possibility of using of Arundo donax L. fibers as reinforcement in polymer composites. The fibers are extracted from the outer part of the stem of the plant, which widely grows in Mediterranean area and is diffused all around the world. To use these lignocellulosic fibers as reinforcement in polymer composites, it is necessary to investigate their microstructure, chemical composition and mechanical properties. Therefore, the morphology of A. donax L. fibers was investigated through electron microscopy, the thermal behavior through thermogravimetric analysis and the real density through a helium pycnometer. The chemical composition of the natura…
An ex-vivo model for transsynovial drug permeation of intraarticular injectables in naive and arthritic synovium
2021
Abstract Estimation of joint residence time of a drug is a key requirement for rational development of intraarticular therapeutics. There is a great need for a predictive model to reduce the high number of animal experiments in early stage development. Here, a Franz-cell based porcine ex-vivo permeation model is proposed, and transsynovial permeation of fluorescently-labeled dextrans in the range of potential drug candidates (10–150 kDa), as well as a small molecule (fluorescein sodium) and charged dextran derivates, have been determined. In addition, a lipopolysaccharide (LPS) -induced synovitis model was assessed for inflammatory biomarker levels and its effect on permeation of the solute…
Injectable in situ forming microgels of hyaluronic acid-g-polylactic acid for methylprednisolone release
2013
Abstract A hydrophobic derivative of hyaluronic acid (HA), obtained by grafting polylactic acid (PLA) to the polysaccharide, has been exploited to produce injectable in situ forming microgels. First of all, self assembling properties of HA-g-PLA copolymer have been evaluated by determining the critical aggregation concentration (CAC) value, then this copolymer has been dissolved in a mixture water/NMP 5:2 v/v with a concentration greater than CAC. When solutions at 1% or 2% w/v were injected into Dulbecco phosphate buffer solution (DPBS) pH 7.4, microgels promptly are formed. Their stability in DPBS pH 7.4 in the absence or in the presence of hyaluronidase and cell compatibility have been e…
Pectin as Drug-Release Vehicle
2020
Pectin as a natural biopolymer is extensively used for pharmaceutical and biomedical applications, essentially due to its gelling properties that could be influenced by pectin sources and extraction methods. This chapter focuses on an overview of pectin drug delivery systems classified by their administration routes. Oral drug delivery systems have been mainly developed, as pectin could be used in tablets as binder or matrix excipients and in microparticles/beads obtained by ionotropic gelation. The main objective is to target the colon, as pectin is resistant in acidic pH and sensitive to pectinolytic enzymes in the colon. To obtain suitable properties, pectin could be used in its native s…
Transcriptome analysis of Pseudomonas mediterranea and P. corrugata plant pathogens during accumulation of medium-chain-length PHAs by glycerol bioco…
2017
Pseudomonas corrugata and P. mediterranea are soil inhabitant bacteria, generally living as endophytes on symptomless plants and bare soil, but also capable of causing plant diseases. They share a similar genome size and a high proteome similarity. P. corrugata produces many biomolecules which play an important role in bacterial cell survival and fitness. Both species produce different medium-chain-length PHAs (mcl-PHAs) from the bioconversion of glycerol to a transparent film in P. mediterranea and a sticky elastomer in P. corrugata. In this work, using RNA-seq we investigated the transcriptional profiles of both bacteria at the early stationary growth phase with glycerol as the carbon sou…
Molecular response of the sponge Suberites domuncula to bacterial infection
2001
The aim of this study was the documentation of the molecular immune response of Suberites domuncula upon bacterial infection. Additionally, the bacteria that are naturally present in the sponge after prolonged aquarium maintenance were characterized. After 6 months of maintenance of S. domuncula in seawater aquaria, only one bacterial 16S rDNA sequence could be recovered, which belongs to the genus Pseudomonas. Concomitantly, morphologically uniform bacteria were found encapsulated in bacteriocytes. These findings indicate that certain bacteria, possibly of the genus Pseudomonas, are able to persist for long periods in host bacteriocytes. Subsequent to performing a previously established in…
N-Glycosylation modification of proteins is an early marker of the enterocytic differentiation process of HT-29 cells
1990
International audience; The human colon cancer cell line HT-29 remains totally undifferentiated when glucose is present in the culture medium (HT-29 Glc+), while the same cells may undergo typical enterocytic differentiation after reaching confluence when grown in glucose-deprived medium (HT-29 Glc-). Recently, we demonstrated a deficiency in the overall N-glycan processing in confluent undifferentiated cells, whereas differentiated cells follow a classical pattern of N-glycosylation. The main changes in N-glycosylation observed in confluent undifferentiated cells may be summarised as follows: 1) the conversion of high mannose into complex glycopeptides is greatly decreased; 2) this decreas…
The Antiviral Activity of Bacterial, Fungal, and Algal Polysaccharides as Bioactive Ingredients: Potential Uses for Enhancing Immune Systems and Prev…
2021
Viral infections may cause serious human diseases. For instance, the recent appearance of the novel virus, SARS-CoV-2, causing COVID-19, has spread globally and is a serious public health concern. The consumption of healthy, proper, functional, and nutrient-rich foods has an important role in enhancing an individual's immune system and preventing viral infections. Several polysaccharides from natural sources such as algae, bacteria, and fungi have been considered as generally recognized as safe (GRAS) by the US Food and Drug Administration. They are safe, low-toxicity, biodegradable, and have biological activities. In this review, the bioactive polysaccharides derived from various microorga…