Plants arabinogalactans: From structures to physico-chemical and biological properties.

Arabinogalactans (AGs) are plant heteropolysaccharides with complex structures occasionally attached to proteins (AGPs). AGs in cell matrix of different parts of plant are freely available or chemically bound to pectin rhamnogalactan. Type I with predominantly ß-d-(1 â†’ 4)-galactan and type II with ß-d-(1 â†’ 3) and/or (1 â†’ 6)-galactan structural backbones construct the two main groups of AGs. In the current review, the chemical structure of AGs is firstly discussed focusing on non-traditional plant sources and not including well known industrial gums. After that, processes for their extraction and purification are considered and finally their techno-functional and biological properties are highlighted. The role of AG structure and function on health advantages such as anti-tumor, antioxidant, anti-ulcer- anti-diabetic and other activites and also the immunomodulatory effects on in-vivo model systems are overviewed.

Purification and Valorization of Waste Cotton Seed Oil as an Alternative Feedstock for Biodiesel Production.

This article is focused on the production of biodiesel from the waste cotton seed oil (WCSO), after purification, as an alternative to fossil fuels. Waste oil was collected from Sodecoton, a factory producing cotton seed oil in the Far North Cameroon. The WCSO was subjected to purification using activated coal, followed by transesterification under basic conditions (potassium hydroxide (KOH)), using methanol and ethanol. Some physico-chemical properties of biodiesel, such as absorbance of waste and purified oil, density, viscosity, water content, acid value, and its energy content were determined. The result of treating the WCSO with activated coal indicated that purification efficiency of activated coal increased with the contact time and the mass of the absorbent. Absorbance results directly proved that activated coal removed unwanted components. In the same way, activated coal concentration and exposure time influenced the level of free fatty acids of WCSO. The yield of methyl ester was 97%, while that of ethyl ester was 98%. The specific gravity at 25 °C was 0.945 ± 0.0601. An evaluation of the lower calorific value (PCI) was done in order to study the energy content of biodiesel. This was found to be a value of 37.02 ± 3.05 MJ/kg for methyl ester and 36.92 ± 7.20 MJ/kg for ethyl ester. WCSO constitutes feedstock for high volume, good quality, and sustainable production of biodiesel, as well as a realistic means of eliminating the pollution resulting from the indiscriminate disposal of waste oils from both household and industrial users.

Structural characterization and rheological properties of a galactomannan from Astragalus gombo Bunge seeds harvested in Algerian Sahara.

A water soluble polysaccharide (WSP) was extracted and purified from Astragalus gombo seeds (Fabaceae) harvested in Septentrional Sahara (Ouargla, Algeria) with a yield of 6.8% (w/w of the dry seed ground). It was characterized by gas chromatography coupled to the mass spectrometry (GC-MS), size exclusion chromatography with Multi-Angle Light Scattering analysis (SEC-MALLS), high-resolution 1H and 13C NMR, and rheological measurements. The structural characterization indicated that this WSP fraction is a galactomannan with a mannose/galactose ratio of 1.7 formed by a backbone of ß-(1,4)-d-mannopyranosyl residues (63%) substituted at O-6 position by a single α-galactopyranose residue (37%). SEC-MALLS analysis revealed that this galactomannan has an average molecular mass (Mw) of 1.1×106g/mol, an intrinsic viscosity of 860mL/g and, a random coil conformation structure. Rheological analysis in semi diluted regimes shown pseudo-plastic and viscoelastic behaviour.

Antioxidant Activities of Peptoid-Grafted Chitosan Films.

The aim of this study was to investigate the possibility of immobilizing peptoid on chitosan film in order to generate new active material. Chitosan films have been grafted for the first time with short-length peptoid oligomers displaying antioxidant activities. The antioxidant activity of the selected peptoids was initially investigated with the DPPH assay and hydroxyl radical procedure. The metal chelating capacity of peptoids was also evaluated prior to their covalent attachment to chitosan. The benefit of chitosan functionalization with respect to its intrinsic antioxidant properties was finally evaluated in the present study. Interestingly, an increase of up to 90 % of the antioxidant activity of chitosan was observed.

Antimicrosporidian activity of sulphated polysaccharides from algae and their potential to control honeybee nosemosis.

Nosemosis is one of the most common and widespread diseases of adult honeybees. The causative agents, Nosema apis and Nosema ceranae, belong to microsporidia some obligate intracellular eukaryotic parasites. In this study, 10 sulphated polysaccharides from algae were evaluated for their antimicrosporidian activity. They were first shown to inhibit the in vitro growth of the mammal microsporidian model, Encephalitozoon cuniculi. The most efficient polysaccharides were then tested for their ability to inhibit the growth of Nosema ceranae in experimentally-infected adult honeybees. Two polysaccharides extracted from Porphyridium spp. did not show any toxicity in honeybees and one of them allowed a decrease of both parasite load and mortality rate due to N. ceranae infection. A decrease in parasite abundance but not in mortality rate was also observed with an iota carrageenan. Our results are promising and suggest that algal sulphated polysaccharides could be used to prevent and/or control bee nosemosis.

Effect of High Irradiance on Depth of Cure of a Conventional and a Bulk Fill Resin-based Composite.

OBJECTIVES: This study evaluated the effect of using three commercial light curing units (LCUs) delivering a range of irradiance values, but delivering similar radiant exposures on the depth of cure of two different resin-based composites (RBCs). METHODS: A conventional hybrid RBC (Z100 shade A2, 3M ESPE) or a bulk fill RBC (Tetric EvoCeram Bulk Fill shade IVA, Ivoclar Vivadent) was packed into a 10-mm deep semicircular metal mold with a 2-mm internal radius. The RBC was exposed to light from a plasma-arc-curing (PAC) light (Sapphire Plus, DenMat) for five seconds, a quartz-tungsten-halogen (QTH) light (Optilux 501, Kerr) for 40 seconds, or a light-emitting-diode (LED) light (S10, 3M ESPE) for 20 seconds and 40 seconds (control). The Knoop microhardness was then measured as soon as possible at the top surface and at three points every 0.5 mm down from the surface. For each RBC, a repeated measures analysis of variance (ANOVA) model was used to predict the Knoop hardness in a manner analogous to a standard regression model. This predicted value was used to determine at what depth the RBC reached 80% of the mean hardness achieved at the top surface with any light. RESULTS: The PAC light delivered an irradiance and radiant exposure of 7328 mW/cm(2) and 36.6 J/cm(2), respectively, to the RBCs; the QTH light delivered 936 mW/cm(2) and 37.4 J/cm(2) and in 20 seconds the LED light delivered 1825 mW/cm(2) and 36.5 J/cm(2). In 40 seconds, the control LED light delivered a radiant exposure of 73.0 J/cm(2). For Z100, using 80% of the maximum hardness at the top surface as the criteria for adequate curing, all light exposure conditions achieved the 2.0-mm depth of cure claimed by the manufacturer. The LED light used for 40 seconds achieved the greatest depth of cure (5.0 mm), and the PAC light used for five seconds, the least (2.5 mm). Tetric EvoCeram Bulk Fill achieved a 3.5-mm depth of cure when the broad-spectrum QTH light was used for 40 seconds delivering 37.4 J/cm(2). It required a 40-second exposure time with the narrow-spectrum LED, delivering approximately 73 J/cm(2) to reach a depth of cure of 4 mm. CONCLUSIONS: When delivering a similar radiant exposure of 37 J/cm(2), the QTH (40 seconds) and LED (20 seconds) units achieved a greater depth of cure than the PAC (five seconds) light. For both resins, the greatest depth of cure was achieved when the LED light was used for 40 seconds delivering 73 J/cm(2) (p<0.05).

Characterization of arabinogalactan-rich mucilage from Cereus triangularis cladodes.

Cereus triangularis (Cactaceae) is a cactus used in food decoction as a traditional medicine in the North region of Madagascar to reduce stomach ache and intestinal diseases. Hydrocolloids were sequentially extracted from its cladodes with a yield of 24% (240 mg/g based on dried cladodes powder). Structural analyses has revealed that this polysaccharide with a molecular mass of 8430,000g/mol was mainly composed of a galactan backbone of a (1 → 4) linked ß-d-Galp residues probably substituted at position 3 by L-arabinofuranosyl residues. In vitro antioxidant activity of this arabinogalactan-rich fraction was detected and quantified by radical DPPH scavenging, hydroxyl radical scavenging, radical anion superoxide scavenging and reducing power method.

Antioxidant activities of a polyglucuronic acid sodium salt obtained from TEMPO-mediated oxidation of xanthan.

A xanthouronic acid sodium salt called xanthouronan was produced from xanthan by regioselective oxidation with NaOCl/NaBr using 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) as catalyst. The efficiency of the one pot TEMPO-mediated oxidation was confirmed by HPAEC-PAD, (13)C NMR, and FT-IR. The oxidation degree was close to 98% and the mass yield of this new polyglucuronic acid was higher than 90% (w/w). The macromolecular characterization of xanthouronan using SEC-MALLS showed a molecular size reduced by a third due to the oxidation treatment and the degree of polymerization (DP) of the xanthouronan form was about 665. The evaluation of the enzymatic degradation of this C-6 carboxylated xanthan by various polysaccharide hydrolases and one polysaccharide lyase showed its high resistant to biodegradation. The antioxidant activity of xanthouronan was also tested by using the 2,2'-diphenyl-1-picrylhydrazyle (DPPH) and hydroxyl radical procedures. At 1 g/L, xanthouronan presented 75% of the ascorbic acid antioxidant activity.

Effect of proteases against biofilms of Staphylococcus aureus and Staphylococcus epidermidis.

UNLABELLED: Biofilms play a key role in bacterial resistance against antibacterial agents-an issue that causes multiple problems in medical fields, particularly with Staphylococcus biofilms that colonize medical indwelling devices. The literature reports several anti-biofilm strategies that have been applied in medicine. Disrupting the biofilm formation process creates new sites open to colonization by treatment-generated planktonic bacteria, so efforts have turned to focus on strategies to prevent and control the initial Staphylococci adhesion. Here, we investigated the preventive activities of three commercial proteases (Flavourzyme, Neutrase and Alcalase) against biofilm formation by two Staphylococcus strains. Some proteolytic extracts revealed interesting results with Staphylococcus epidermidis and Staphylococcus aureus aureus biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: Three proteases were tested against Staphylococcus aureus and Staphylococcus epidermidis biofilms in standard conditions. The Flavourzyme containing a mix of Aspergillus orizae endo- and exoproteases demonstrated significant efficacy against Staph. epidermidis biofilm formation. These results could prove valuable in the effort to develop simple anti-biofilm methods.

The health of adolescents around a world in transition.

Since several years, the health of adolescents is on the agenda of ministers, decision makers and health professionals. Around the world, while there has been a steady decrease of the death rates among young children, this is not the case for young people. This is mainly linked with the fact that mortality and morbidity during this period of life is largely linked with non communicable diseases and conditions, including deaths from injuries, suicide, homicides and drug abuse. Unplanned pregnancies, illegal abortions, newly acquired HIV infections are also situations that have short and long term consequences. This paper reviews the epidemiological data pertaining to adolescent health and disease. It proposes evidence-informed avenues as how to address these issues in the field of health care (e.g. adolescent friendly services) and of prevention and health promotion. It also stresses the importance of creating safe environments for the development and well-being of young people and thus, of an interdisciplinary and inter sectorial approach to their complex health problems and challenges.

Anticancer activity of chemically prepared shrimp low molecular weight chitin evaluation with the human monocyte leukaemia cell line, THP-1.

In the present study, anticancer activities of chitin, chitosan and low molecular weight chitin were evaluated using a human tumour cell line, THP-1. A molecular weight-activity relationship and an electrostatic interaction-activity relationship were determined. The cytotoxic effects of chitin and derivatives were also evaluated using a normal human foetal lung fibroblastic cell line, MRC-5 and the specific cytotoxicity of chitin and derivatives to tumour cell lines was demonstrated. The high antitumour effect of low molecular weight of chitin was established.

Antioxidant activities of polyphenols extracted from olive (Olea europaea) of chamlal variety.

The antioxidant properties of phenolic compounds from olive pulp (PCO) of chamlal variety and those of individual phenolic compounds were evaluated and compared with that of vitamin C (Vit C). The antioxidant activity was measured by the tests of iron reduction and scavenging hydrogen peroxide (H(2)O(2)). Results showed that all the substances tested exhibit a reducing power. The PCO present activities of iron reduction and H(2)O(2) scavenging higher than those of Vit C. The protective effect of PCO against oxidation of lipids and proteins from erythrocyte membranes was studied. The measurement of malondialdehyde generated under oxidative stress conditions induced by hydroxyl radicals generating system revealed that PCO have the most significant protective activity against lipid peroxidation (IC(50) = 49.27 ± 1.91 µg mL(-1)). Paradoxically, Vit C revealed a pro-oxidant effect. Proteins oxidation was evaluated using the H(2)O(2)/FeSO(4) system and electrophoresis. In the presence of PCO at 1 mg mL(-1), proteins of erythrocyte membranes were protected contrary to those treated with Vit C at the same concentration.

A new method to screen polysaccharide cleavage enzymes.

The activity of polysaccharide cleavage enzymes has usually been evaluated by qualitative plate screening methods and quantitative colorimetric or chromatographic assays. The recent development of protein engineering has shown the limits of these techniques when applied to high throughput screening. Here we propose a microplate method to measure the activity of polysaccharide cleavage enzymes through small variations in viscosity. Polysaccharide solutions are co-incubated with magnetic particles in enzyme buffers. The cleavage action of polymer-degrading enzymes increases the mobility of the particles in a magnetic field, even at low levels of enzyme activities. This reproducible, sensitive technique was used to evaluate enzymatic specificity towards substrates. BioFilm indices (BFI) determined by associated software were used to follow enzyme kinetics and measure the usual variables.

[Anorexia and bulimia: the canton of Vaud's experience of an interdisciplinary approach]. / Anorexie mentale et boutimie: I'expérience vaudoise d'une prise en charge interdisciplinaire.

As psychiatric disorders attacking the body, anorexia and bulimia may have severe psychological, physical and social consequences, often requiring a long-standing interdisciplinary, coordinated and individualized approach. Recently the canton of Vaud has initiated and developed an interinstitutional structure--between the University Hospital (CHUV) and the hospitals of the Northern region of the canton (eHnv)--for the care of patients suffering from eating disorders. This structure, allowing the above mentioned approach for the treatment of eating disorders, consists of an outpatient facility located in the CHUV and an inpatient unit in the hospital of Saint Loup of the eHnv. Within this structure, the general practitioner plays a crucial role in the prevention of the chronification of these disorders by means of their early detection and management.

New perspectives for Lactobacilli exopolysaccharides.

Lactobacilli have the ability to produce different kinds of exopolysaccharides (EPS) exhibiting a wide diversity of structures. EPS are classified, according to their composition into homopolysaccharides and heteropolysaccharides. One of their most described applications is their utilization as texturing agents naturally synthesized in the fermented food products. Nowadays, in regard to demand of modern consumers focusing towards safe and healthy food without additives, new perspectives of development appear for these biopolymers. The GRAS (Generally Recognized As Safe) and probiotic status of some lactobacilli give to them more preference for consumable EPS production. The main drawbacks limiting their industrial expansion are their low yields of production and the validation of their healthy allegations. Moreover, the texturing role of these exopolysaccharides, notably in dairy products, is actually a controversial issue. This review focuses on the novel ways of EPS production employing Lactobacillus spp. and their potential as nutraceuticals.

A new tool to detect high viscous exopolymers from microalgae.

Microalgae are microorganisms often surrounded by a slime layer made of secreted polymeric substances sometimes including polysaccharides. These polysaccharides, weakly described in the literature, can constitute value-added molecules in several industrial areas. The aim of this article is to show that a new tool, the BioFilm Ring Test®, can be used to detect viscous microalgal exopolymers. Two red microalgal strains (Rhodella violacea and Porphyridium purpureum), one cyanobacterium (Arthrospira platensis) and their excreted polymeric fractions were studied. R. violacea and P. purpureum induced a positive response with the BioFilm Ring Test® contrary to A. platensis. Finally, the understanding of the fractions viscosity involvement in the BRT response was performed by a rheological study.

[Extensive iatrogenic coronary dissection during coronary angioplasty: a series of 19 consecutive patients]. / Dissection coronaire extensive compliquant une angioplastie: à propos d'une série de 19 cas consécutifs.

PURPOSE OF THE STUDY: Extensive coronary dissection is a rare complication of intraluminal angioplasty. We report a retrospective study of 19 patients who consulted in a general hospital without cardiac surgery. PATIENTS AND METHODS: After consulting our coronarography and angioplasty database, we included the extensive coronary dissections (type D, E and F) in our study. The medical files of the selected patients were analysed. RESULTS: Between January 2003 and March 2010, 19 coronary angioplasty (total: 2542) were complicated with extensive dissections (incidence 0,75%). For 62,3% of the patients, the dissection was related to the guiding catheter. Eleven patients had type A and B1 lesions. The dissections affected the right coronary artery for 16 patients, the left anterior descending coronary artery for two patients and the left main coronary artery for one patient. After angioplasty, a final TIMI flow 3 was obtained for only 11 patients. In nine cases, we observed a limited extension to the aorta that did not need a chirurgical intervention and had no influence on the prognosis. The complications were common, such as death (n=1), coronary bypass (n=2), myocardial infarction (n=8), cardiogenic shock (n=2) and circulatory assistance (n=2). CONCLUSION: Extensive coronary dissection is a rare complication of angioplasty. The right coronary is the most frequent vessel concerned and an extension to aorta is usual. The treatment is usually based on sealing the entry with a coronary stent. The complications are common and serious and we did not find any predicting factors to extensive coronary dissections that are unpredictable.