Uncontrolled study assessing the impact of a psyllium-enriched extruded dry diet on faecal consistency in cats with constipation

Two field trials, involving 66 cats (15 trial 1; 51 trial 2) were conducted to assess the efficacy of a psyllium-enriched diet for management of constipation in cats. After investigations and faecal evacuation (by enema if required), all cats were fed on a moderate fibre, psyllium-enriched, dry extruded diet. Additional therapy was either not used (trial 1), or initially allowed but was subsequently withdrawn if possible (trial 2). The diet was well tolerated, and palatability was excellent. Most cases improved after initial therapy (at 2 months; trial 1: 14/15 [93%]; trial 2: 42/51 [82%]), and faecal consistency improved significantly in both trials (P < 0.001). Use of cisapride and lactulose decreased significantly in trial 2 (P < 0.001 for both). The diets used in these pilot studies were efficient in the management of recurrent feline constipation. Randomised control trials are now recommended to examine whether a clinical benefit can be proven.     

Near-perfect elastoplasticity in pure nanocrystalline copper

Ductile metals and alloys undergo plastic yielding at room temperature, during which they exhibit work-hardening and the generation of surface instabilities that lead to necking and failure. We show that pure nanocrystalline copper behaves differently, displaying near-perfect elastoplastic behavior characterized by Newtonian flow and the absence of both work-hardening and neck formation. We observed this behavior in tensile tests on fully dense large-scale bulk nanocrystalline samples. The experimental results further our understanding of the unique mechanical properties of nanocrystalline materials and also provide a basis for commercial technologies for the plastic (and superplastic) formation of such materials.     

Antimicrobial Peptides from Marine Proteobacteria

After years of inadequate use and the emergence of multidrug resistant (MDR) strains, the efficiency of “classical” antibiotics has decreased significantly. New drugs to fight MDR strains are urgently needed. Bacteria hold much promise as a source of unusual bioactive metabolites. However, the potential of marine bacteria, except for Actinomycetes and Cyanobacteria, has been largely underexplored. In the past two decades, the structures of several antimicrobial compounds have been elucidated in marine Proteobacteria. Of these compounds, polyketides (PKs), synthesised by condensation of malonyl-coenzyme A and/or acetyl-coenzyme A, and non-ribosomal peptides (NRPs), obtained through the linkage of (unusual) amino acids, have recently generated particular interest. NRPs are good examples of naturally modified peptides. Here, we review and compile the data on the antimicrobial peptides isolated from marine Proteobacteria, especially NRPs.     

Alterins Produced by Oyster-Associated Pseudoalteromonas Are Antibacterial Cyclolipopeptides with LPS-Binding Activity

Discovery after discovery, host-associated microbiota reveal a growing list of positive effects on host homeostasis by contributing to host nutrition, improving hosts’ immune systems and protecting hosts against pathogens. In that context, a collection of oyster associated bacteria producing antibacterial compounds have been established to evaluate their role in non-host-derived immunity. Here, we described alterins; potent anti-Gram negative compounds produced by Pseudoalteromonas hCg-6 and hCg-42 isolated from different healthy oyster hemolymph. The strains hCg-6 and hCg-42 produce a set of at least seven antibacterial compounds, ranging from 926 to 982 Da structurally characterized as cyclolipopeptides (CLPs). Alterins share the same cationic heptapeptidic cycle connected via an amido bond to different hydrophobic hydrocarbon tails. Their MICs disclosed a potent antibacterial activity directed against Gram-negative bacteria including oyster and human pathogens that may confer a beneficial defense mechanism to the host but also represents an untapped source of new antibiotics. The alterins’ mechanisms of action have been deciphered: after binding to lipopolysaccharides (LPS), alterins provoke a membrane depolarization and permeabilization leading to bacterial lysis. As hCg-6 and hCg-42 produced a set of natural derivatives, the structure/activity relationship linked to the carbon tail is clarified. We showed that the hydrocarbon tail determines the LPS-binding properties of alterins and consequently their antibacterial activities. Its length and saturation seem to play a major role in this interaction.     

Effect of null mutations in the AbNIK1 gene on saprophytic and parasitic fitness of Alternaria brassicicola isolates highly resistant to dicarboximide fungicides

Alternaria brassicicola field isolates highly resistant to dicarboximide fungicides (DCF) and carrying non‐sense codons or micro‐deletions in the AbNIK1 gene encoding a group III histidine kinase were characterized at the protein level using specific antibodies. These isolates, as well as laboratory mutants expressing the same resistant phenotype, were shown to correspond to null mutants. The fitness of these isolates was compared to that of wild‐type isolates by measuring i) mycelial growth, ii) sporulation and iii) conidial germination under standard conditions. None of these factors were affected in the resistant isolates. Mycelial growth was also measured under stress conditions. Unlike suboptimal incubation temperatures or exposure to the superoxide ion generator menadione, osmotic stress generated by high sorbitol concentrations in the culture medium significantly affected the growth of AbNIK1‐null mutants compared to wild‐types. The effects of these mutations on parasitic fitness were estimated under both controlled and field conditions after inoculation of radish with individual isolates, to measure their aggressiveness, or with mixed conidial suspensions, to measure their competitive ability against wild‐type isolates. These tests on radish seedlings revealed that DCF‐resistant isolates were still aggressive. Despite this, the data obtained in the competition experiments showed that the loss of the ability to synthesize AbNIK1p in A. brassicicola DCF‐resistant mutants was linked to a severe decrease in their competitiveness.     

<Emphasis Type="Italic">Alternaria</Emphasis> species associated with early blight epidemics on tomato and other <Emphasis Type="Italic">Solanaceae</Emphasis> crops in northwestern Algeria

Clubroot, caused by the protozoan parasite Plasmodiophora brassicae Woronin, is one of the most damaging diseases of Brassica napus worldwide. Resistant plant material is valuable for cultivation in all areas of high incidence of the disease and intensive growth of oilseed rape. We have evaluated clubroot resistance, plant morphology and seed quality in 15 lines of an F₄ generation and selected six lines of F₅ generation of interspecific hybrids obtained from a cross between a male sterile line of B. napus ‘MS8’, selected from resynthesized oilseed rape (B. rapa ssp. chinensis × B. oleracea var. gemmifera) and an ecotype of B. rapa ssp. pekinensis. Clubroot resistance was evaluated using a bioassay with P₁-P₅ pathotypes of P. brassicae (according to the classification of Somé et al. 1996). The resistance to the pathotype P₁ was successfully fixed in the F₅ generation, and improved in some lines in respect to the pathotypes P₂-P₄. The resistance to P₁ and the other tested pathotypes was not linked. Characterization of plant material included recent techniques of FISH and BAC-FISH with a special focus on the analysis of ribosomal DNA (rDNA) of selected individuals. Two hybrid lines combined high levels of resistance with appropriate plant morphology, good seed quality traits and a stable chromosome number and arrangement. Recent techniques of ‘chromosome painting’ provided good insight into chromosome organization in the hybrids obtained, and offered opportunities of further improvement of the breeding process.     

ANATOMICAL STUDY OF CRANIAL NERVE EMERGENCE AND SKULL FORAMINA IN THE DOG USING MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY

Twenty-two magnetic resonance imaging (MRI) brain studies of different breeds of dogs were reviewed to assess the anatomy of cranial nerve (CN) origins and associated skull foramina. These included five anatomic studies of normal brains using 2-mm-thick slices and 17 studies using conventional clinical protocols with 3- or 4-mm slices on both normal and abnormal brains. Images were obtained in transverse, sagittal, and dorsal planes to allow a thorough comparison between studies. CNs II, III, V (and its divisions), and VIII were observed consistently on conventional studies. On the thin-slice studies, the origins and proximal portions of CNN IV, VII, and the group of IX, X, and XI could be seen. The origins of CNN VI and XII were not observed with certainty. In parallel, a computed tomography study of an isolated skull was performed with a thin copper wire within each of the skull foramina to determine precisely each CN exit and to facilitate recognition of the course of CNs when exiting the skull on MRI images.