Enzymes of the small intestine of the calf: effect of dietary protein source on the activities of some enzymes in the small intestinal mucosa and digesta

The objective of this study was to examine the effect of dietary protein source on the morphology and enzyme activities in the small intestinal mucosa and digesta of preruminant calves. The control diet contained skim milk powder. Plant proteins from soy concentrate (unhydrolysed or partially hydrolysed) and potato concentrate were incorporated into experimental diets. Duodenal, jejunal and ileal mucosal biopsies and digesta were collected from calves fitted with simple cannulae and continuously infused with milk replacers into the abomasum. Biopsies were used for morphology measurements. The activity of dipeptidylpeptidase IV, aminopeptidases, lactase and alkaline phosphatase was estimated in biopsies and digesta. Incorporating plant protein had a limited effect on the intestinal mucosa. A partial villus atrophy and crypt hyperplasia were noted with the soy concentrate only. Decreases in the activity of dipeptidylpeptidase IV with the potato concentrate diet and of aminopeptidase N and lactase with the hydrolysed soy concentrate diet, were also observed in ileal biopsies. Mucosal enzymes were released in the lumen and most of them accumulated in digesta of the distal small intestine. The activity of aminopeptidase N and lactase in ileal digesta was higher in calves fed the soy and potato concentrate diets than in those fed the control diet. © 2002 Society of Chemical Industry     

Short-term changes in bacterial community fingerprints and potential activities in an alfisol supplemented with solid waste leachates

We investigated the effect on soil functioning of adding leachates from municipal solid waste incinerator (MSWI) ashes to laboratory columns (bare soil) and to field experimental plots (bare soil or grass cover). Leachate of MSWI-solidified air pollution control residues (SAPCr) contained more salts but less heavy metals than did MSWI-bottom ash (BA) leachate. Leachate-supplemented soils (BA soil, SAPCr soil) and control (water added) soil (W) were analyzed after 30 days. Potential denitrifying activity (PDA) and potential N2 fixation (acetylene reduction assay, ARA) were measured in controlled conditions. PDA was significantly lower in SAPCr soil than in W soil, both in the laboratory (-45%) and in bare soil in the field (-31%). ARA values were lower in bare SAPCr soil (-54%) and in bare BA (-25%) soil. Both activities remained unaffected by leachate supplementation in soil under permanent grass cover. Automated ribosomal intergenic spacer analysis (A-RISA) fingerprints and RFLP of nifH gene pools were used to assess changes in the structure of bacterial community. Multivariate analysis of these fingerprints revealed that SAPCr leachate had a stronger effect than BA leachate on the total and N2-fixing bacterial communities. Similar results were obtained for laboratory and bare soil field plots, but leachates did not affect nifH gene pools from soil under permanent grass cover. The stronger impact of SAPCr leachate on both structure of bacterial communities and activities supports the conclusion that observed effects would result from the abundance of salts rather than from heavy metal toxicity.     

Ionic dialysance: principle and review of its clinical relevance for quantification of hemodialysis efficiency

Ionic dialysance (D) is an online measured variable now available on several dialysis monitors to evaluate small-solute clearance. Based on conductivity measurements in the inlet and outlet dialysate, the principle of the measurement and the different measurement methods are described. Studies that have evaluated the reliability of ionic dialysance to assess dialysis efficiency are discussed. These studies are divided into two groups: the first comparing ionic dialysance to urea clearance and the second comparing Dt/V to Kt/V(urea), in which the uncertainties of the measurement of V(urea) could have misrepresented the relationship between Dt/V and Kt/V(urea). When Kt/V(urea) via the Daugirdas second-generation equation taking the rebound into account is considered, slight-even nonsignificant-differences are evidenced between Kt/V(urea) and Dt/V. Therefore, ionic dialysance should be considered as a valid measure in future guidelines for dialysis efficiency.     

Impact of cooling rates on the staling behavior of cooked rice during storage

The impact of cooling rates (0.40, 1.11, 1.42, 1.64, 2.47 and 3.36 °C/min) on starch retrogradation and textural properties of cooked rice was evaluated. The relationship between cooling rates and different properties were determined using Pearson correlation. Starch retrogradation enthalpy (ΔH_r) of cooked rice was determined by differential scanning calorimetry, and textural properties were determined by a Texture Analyser. This study showed that the ΔH_r value and hardness value had a negative correlation with cooling rate during storage, −0.963  r  −0.716, P < 0.01; −0.826  r  −0.706, P < 0.05, respectively. However, a positive correlation was found between adhesiveness and cooling rate (0.237  r  0.882, P < 0.05). These results indicated that the cooked rice chilled with slower cooling rate retrograded faster than chilled with rapid cooling rate. Therefore, high quality cooked rice can be produced by rapid cooling process.     

Investigating Pathogenicity and Virulence of Staphylococcus pettenkoferi: An Emerging Pathogen

Staphylococcus pettenkoferi is a coagulase-negative Staphylococcus identified in 2002 that has been implicated in human diseases as an opportunistic pathogenic bacterium. Its multiresistant character is becoming a major health problem, yet the pathogenicity of S. pettenkoferi is poorly characterized. In this study, the pathogenicity of a S. pettenkoferi clinical isolate from diabetic foot osteomyelitis was compared with a Staphylococcus aureus strain in various in vitro and in vivo experiments. Growth kinetics were compared against S. aureus, and bacteria survival was assessed in the RAW 264.7 murine macrophage cell line, the THP-1 human leukemia monocytic cell line, and the HaCaT human keratinocyte cell line. Ex vivo analysis was performed in whole blood survival assays and in vivo assays via the infection model of zebrafish embryos. Moreover, whole-genome analysis was performed. Our results show that S. pettenkoferi was able to survive in human blood, human keratinocytes, murine macrophages, and human macrophages. S. pettenkoferi demonstrated its virulence by causing substantial embryo mortality in the zebrafish model. Genomic analysis revealed virulence factors such as biofilm-encoding genes (e.g., icaABCD; rsbUVW) and regulator-encoding genes (e.g., agr, mgrA, sarA, saeS) well characterized in S. aureus. This study thus advances the knowledge of this under-investigated pathogen and validates the zebrafish infection model for this bacterium.     

Conception and Evaluation of Fluorescent Phosphine-Gold Complexes: From Synthesis to in vivo Investigations

A phosphine gold(I) and phosphine-phosphonium gold(I) complexes bearing a fluorescent coumarin moiety were synthesized and characterized. Both complexes displayed interesting photophysical properties: good molar absorption coefficient, good quantum yield of fluorescence, and ability to be tracked in vitro thanks to two-photon imaging. Their in vitro and in vivo biological properties were evaluated onto cancer cell lines both human and murine and into CT26 tumor-bearing BALB/c mice. They displayed moderate to strong antiproliferative properties and the phosphine-phosphonium gold(I) complex induced significant in vivo anti-cancer effect.     

High-performance KNN piezoceramics with reproducibility and chemical stability. Part I: Solid-state reaction route

(K,Na)NbO₃-based compounds are attracting much attention for their high potential as Pb-free piezoelectric ceramics. They have, however, three major drawbacks to overcome in order to achieve a mature development: densification, reproducibility, and chemical stability. In this first part, based on standard solid-state reaction, the way to synthesize high-density homogeneous ceramics with high piezoelectric performance and chemical stability is elucidated. It relies on a low-temperature spark-plasma sintering process, after the raw materials have been finely pulverized prior to reaction. The reproducibility, however, remains a pending issue due to the unavoidable random formation of parasitic phases.