The Role of Platelets in Infective Endocarditis.

Over the last decade, the incidence of infective endocarditis (IE) has increased, with a change in the frequency of causative bacteria. Early evidence has substantially demonstrated the crucial role of bacterial interaction with human platelets, with no clear mechanistic characterization in the pathogenesis of IE. The pathogenesis of endocarditis is so complex and atypical that it is still unclear how and why certain bacterial species will induce the formation of vegetation.

A rare case of Neuhauser syndrome associated with a Kommerell diverticulum.

Neuhauser syndrome is a rare vascular anomaly characterized by the esophagus and trachea circling via the ligamentum arteriosum and right aortic arch. Kommerell's diverticulum have the same characteristic by an outpouch at the onset of an aberrant left subclavian artery worsening this compression. The association between these pathologies is very rare and the operative strategy is unclear.

Synergistic Antimicrobial Effect of Chitosan Polymers and Oligomers.

This study evaluated the efficacy of the combined application of well-characterized chitosan polymer (degree of acetylation = 10%, degree of polymerization [DPn] = 90, and dispersity [Ð] = 2.8) and oligomers (partially acetylated chitosan polymers and oligosaccharides [paCOS]) (DP = 2 to 17) on conidia germination and mycelial growth of , the major causal agent of Fusarium head blight in wheat. The polymer alone showed a higher inhibitory effect than the paCOS mixture alone, with half-maximal inhibitory concentrations of less than 50 µg ml and more than 100 µg ml, respectively.

Anterograde blood flow associated with modified Blalock-Taussig shunt does not modify pulmonary artery growth compared with modified Blalock-Taussig shunt alone.

Background: The main difference between extreme tetralogy of Fallot (TOF) and pulmonary atresia with ventricle septal defect (PA/VSD) is anterograde pulmonary blood flow (APBF). It is speculated that the association of modified Blalock-Taussig shunt (mBTS) with APBF favours shunt thrombosis, but promotes better pulmonary artery growth.

Aim: To compare pulmonary artery growth after mBTS between TOF and PA/VSD.

Pulmonary atresia with ventricular septal defect and tetralogy of Fallot: transannular path augmentation versus systemic to pulmonary artery shunt for first-stage palliation.

Background: Pulmonary atresia with ventricular septal defect and severe tetralogy of Fallot require a palliative procedure for pulmonary artery rehabilitation. For first-stage palliation, two main surgical options are still debated: right ventricle to pulmonary artery connection and modified Blalock-Taussig shunt. We compared the clinical outcomes of the two procedures.

The Pattern of Acetylation Defines the Priming Activity of Chitosan Tetramers.

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of β-1,4-linked glucosamine (deacetylated/D) and -acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially acetylated chitosan oligosaccharides from a chitosan polymer (DA = 35%, DP = 905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities.

'Slipped Sandwich' Model for Chitin and Chitosan Perception in Arabidopsis.

Chitin, a linear polymer of N-acetyl-d-glucosamine, and chitosans, fully or partially deacetylated derivatives of chitin, are known to elicit defense reactions in higher plants. We compared the ability of chitin and chitosan oligomers and polymers (chitin oligomers with degree of polymerization [DP] 3 to 8; chitosan oligomers with degree of acetylation [DA] 0 to 35% and DP 3 to 15; chitosan polymers with DA 1 to 60% and DP approximately 1,300) to elicit an oxidative burst indicative of induced defense reactions in Arabidopsis thaliana seedlings. Fully deacetylated chitosans were not able to trigger a response; elicitor activity increased with increasing DA of chitosan polymers.

Synthesis, Characterization and Biological Activities of Biopolymeric Schiff Bases Prepared with Chitosan and Salicylaldehydes and Their Pd(II) and Pt(II) Complexes.

In an attempt to enhance chitosan biological activities, biopolymeric Schiff bases of chitosan and different salicylaldehydes and their palladium(II) and platinum(II) complexes were synthesized and tested. The chemical structures of these derivatives were characterized using ¹H-NMR, FTIR spectroscopy and XPRD. Thermal analysis was done through TGA/DTG-DTA.

Chitinosanase: A fungal chitosan hydrolyzing enzyme with a new and unusually specific cleavage pattern.

The biological activities of partially acetylated chitosan oligosaccharides (paCOS) depend on their degree of polymerization (DP), fraction of acetylation (F), and potentially their pattern of acetylation (P). Therefore, analyzing structure-function relationships require fully defined paCOS, but these are currently unavailable. A promising approach for obtaining at least partially defined paCOS is using chitosanolytic enzymes.

A Recombinant Fungal Chitin Deacetylase Produces Fully Defined Chitosan Oligomers with Novel Patterns of Acetylation.

Unlabelled: Partially acetylated chitosan oligosaccharides (paCOS) are potent biologics with many potential applications, and their bioactivities are believed to be dependent on their structure, i.e., their degrees of polymerization and acetylation, as well as their pattern of acetylation.

Physical Properties and Stability of Soft Gelled Chitosan-Based Nanoparticles.

We addressed the role of the degree of acetylation (DA) and of M of chitosan (CS) on the physical characteristics and stability of soft nanoparticles obtained through either ionic cross-linking with sodium tripolyphosphate (TPP), or reverse emulsion/gelation. Each of these methods affords nanoparticles (NPs) or nanogels (NGs), respectively. The size of CS-TPP NPs comprising CS of high M (≈123-266 kDa) increases with DA (≈1.

Production of bioactive chitosan oligosaccharides using the hypertransglycosylating chitinase-D from Serratia proteamaculans.

The biological activities of chitosan and its oligosaccharides are greatly influenced by properties such as the degree of polymerization (DP), degree of acetylation (DA) and pattern of acetylation (PA). Here, structurally diverse chitosan oligosaccharides from chitosan polymers (DA=35% or 61%) were generated using Serratia proteamaculans wild-type chitinase D (SpChiD) and the W114A mutant which lacks transglycosylase activity. The crude oligosaccharide mixtures and purified fractions with specific DP and DA ranges were tested for their ability to induce an oxidative burst in rice cell suspension cultures.

A rational approach towards the design of chitosan-based nanoparticles obtained by ionotropic gelation.

Chitosan is a linear aminopolysaccharide that has been widely used for the formation of chitosan-based nanoparticles by ionic gelation with sodium tripolyphosphate (TPP). Often, the experimental design used to obtain these systems does not take into consideration important variables, such as the degree of acetylation (DA) and the molecular weight (Mw) of chitosan. In this work, we studied the formation of chitosan-TPP nanoparticles with chitosan samples of varying DA and Mw (DA0 ∼ 0-47% and Mw ∼ 2.

Catalytic efficiency of chitinase-D on insoluble chitinous substrates was improved by fusing auxiliary domains.

Chitin is an abundant renewable polysaccharide, next only to cellulose. Chitinases are important for effective utilization of this biopolymer. Chitinase D from Serratia proteamaculans (SpChiD) is a single domain chitinase with both hydrolytic and transglycosylation (TG) activities.

Experimental and bioinformatic characterization of a recombinant polygalacturonase-inhibitor protein from pearl millet and its interaction with fungal polygalacturonases.

Polygalacturonases (PGs) are hydrolytic enzymes employed by several phytopathogens to weaken the plant cell wall by degrading homopolygalacturonan, a major constituent of pectin. Plants fight back by employing polygalacturonase-inhibitor proteins (PGIPs). The present study compared the inhibition potential of pearl millet PGIP (Pennisetum glaucum; PglPGIP1) with the known inhibition of Phaseolus vulgaris PGIP (PvPGIP2) against two PGs, the PG-II isoform from Aspergillus niger (AnPGII) and the PG-III isoform from Fusarium moniliforme (FmPGIII).

Biotechnological approaches for field applications of chitooligosaccharides (COS) to induce innate immunity in plants.

Plants have evolved mechanisms to recognize a wide range of pathogen-derived molecules and to express induced resistance against pathogen attack. Exploitation of induced resistance, by application of novel bioactive elicitors, is an attractive alternative for crop protection. Chitooligosaccharide (COS) elicitors, released during plant fungal interactions, induce plant defenses upon recognition.

Complexation of copper(II) with chitosan nanogels: toward control of microbial growth.

Pure chitosan nanogels were produced, used to adsorb copper(II), and their antimicrobial activities were assessed. The complexation of copper(II) with chitosan solutions and dispersions was studied using UV-vis spectrometry. The adsorption capacity of chitosan nanogels was comparable to that of chitosan solutions, but copper(II)-loaded nanogels were more stable (i.

Growth rate inhibition of phytopathogenic fungi by characterized chitosans.

The inhibitory effects of fifteen chitosans with different degrees of polymerization (DP) and different degrees of acetylation (FA) on the growth rates (GR) of four phytopathogenic fungi (Alternaria alternata, Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer) were examined using a 96-well microtiter plate and a microplate reader. The minimum inhibitory concentrations (MICs) of the chitosans ranged from 100 μg ×mL(-1) to 1,000 μg ×mL(-1) depending on the fungus tested and the DP and FA of the chitosan. The antifungal activity of the chitosans increased with decreasing FA.

Partially acetylated chitosan oligo- and polymers induce an oxidative burst in suspension cultured cells of the gymnosperm Araucaria angustifolia.

Suspension-cultured cells were used to analyze the activation of defense responses in the conifer A. angustifolia , using as an elicitor purified chitosan polymers of different degrees of acetylation (DA 1-69%), chitin oligomers of different degrees of polymerization (DP 3-6), and chitosan oligomer of different DA (0-91%). Suspension cultured cells elicited with chitosan polymers reacted with a rapid and transient generation of H2O2, with chitosans of high DA (60 and 69%) being the most active ones.

Growth of phytopathogenic fungi in the presence of partially acetylated chitooligosaccharides.

Four phytopathogenic fungi were cultivated up to six days in media containing chitooligosaccharide mixtures differing in average DP and FA. The three different mixtures were named Q3 (which contained oligosaccharides of DP2-DP10, with DP2-DP7 as main components), Q2 (which contained oligosaccharides of DP2-DP12, with DP2-DP10 as main components) and Q1 (which derived from Q2 and contained oligomers of DP5-DP8 with hexamer and a heptamer as the main components). The novel aspect of this work is the description of the effect of mixtures of oligosaccharides with different and known composition on fungal growth rates.

Partial restoration of all trans retinoic acid (ATRA) sensitivity by compactin in ATRA-resistant leukemic cells (ATRA-R HL-60).

The resistance to all trans retinoic acid (ATRA) differentiating treatment is a consequence, in most of the cases, of either increased catabolism or down regulation of ATRA uptake. Recently, we have shown that ATRA efficiency to differentiate HL-60 cells was enhanced about 30 times after its incorporation into Low Density Lipoprotein (ATRA-LDL). Here, we attempted to differentiate the ATRA-resistant HL-60 cells by ATRA-LDL at high concentrations up to 10 microM.

Effects of all-trans-retinoic acid incorporated into low-density lipoprotein on invasive properties of multidrug-resistant MCF-7 spheroids.

Cultured cells grown as spheroids provide an in vitro model that is closer to an in vivo tumour than conventional monolayer techniques. Previous work from our laboratory has demonstrated that spheroids formed from multidrug-resistant MCF-7 cells exhibit invasive characteristics which were not present in their sensitive counterparts. The treatment of these spheroids by all-trans-retinoic acid (ATRA), a potent inducer of in vitro and in vivo differentiation, decreases their proteolytic activity and ability to invade Matrigel-coated filters.

Enhancement of all-trans-retinoic acid efficiency in granulocytic differentiation of HL-60 cells by incorporation into low density lipoprotein.

All-trans-retinoic acid (ATRA) has been proven to lead to complete remission of acute promyelocytic leukemia by inducing differentiation into granulocytes except when an acquired resistance occurred. High levels of low density lipoprotein (LDL) receptor in cancer cells suggested the use of ATRA incorporated into LDL. 50% of HL-60 cell differentiation were obtained with 5 nmoles/l of ATRA-LDL compared to 150 moles/l of ATRA.

Involvement of tyrosine kinase activity in the low-density lipoprotein receptor expression in human lung adenocarcinoma cell line A549.

In common with other tumour cell lines but in contrast to normal cells, the human adenocarcinoma cell line A549 showed a biphasic regulation of the LDL receptor activity during growth both LDL binding and metabolism (sum of internalised and degraded LDL) increased during the log exponential growth phase and decreased when the cells approached confluence. This period of increasing LDL receptor activity coincided with a high resistance to cholesterol down-regulation which suggested a sterol-independent pathway of stimulation. Since A549 cells have an autocrine loop of growth factors, two of which have tyrosine kinase activity, the LDL receptor activity was tested in the presence of the tyrosine kinase inhibitor, genistein.

[Levels of the training of psychotherapists and results of analytic psychotherapy].

The purpose of this study was to investigate therapists experience as predictor of psychotherapy outcome. We studied consecutive patients (n = 76) assigned to psychoanalytic psychotherapy after being referred to the Geneva University Psychiatric Center for psychiatric treatment. Fifty-seven subjects were treated by trainees and nineteen had certified psychotherapists.