Usefulness of the stomacher in a microbiological regulatory laboratory.

The relative efficiency of the Waring blender, the Stomacher 400, and the Stomacher 3500 for preparing food samples for microbiological analysis was studied. Comparative aerobic plate count (APC) values were determined on 671 samples, representing 30 categories of foods. Of the 26 categories of nonfatty foods, the blender gave significantly higher geometric mean APC values than those given by the Stomacher 400 and the Stomacher 3500 in 65 and 69 percent of the categories, respectively. In a comparison of the two Stomacher models, the Stomacher 400 gave significantly higher geometric mean APC values than these given by the Stomacher 3500 in 73 percent of the food categories. Addition of Tween 80 to four categories of fatty foods at concentrations of 0.5, 1.0, and 2.0 percent did not raise the APC values given by either model of stomacher to the levels given by the Waring blender. Overall, the efficiency of both models of Stomacher, relative to the blender and to each other, was specific and depended upon the particular food being analyzed.     

Diversity of gut Bifidobacterium species is not altered between allergic and non-allergic French infants

Some clinical studies have suggested a relationship between allergic diseases and gut microbiota. We aimed to study bifidobacterial colonization at species and strain levels in ten allergic French infants included at their first clinical consultation and 20 controls matching for age at sampling, mode of delivery, per partum antibiotics, type of feeding and antibiotics in the first weeks of life. The faecal microbiota was analyzed by culture methods and TTGE. Bifidobacterial species and strains were identified using multiplex PCR and Box-PCR fingerprinting. No differences were observed between groups in the number of colonized infants or in the levels of colonization by the main aerobic and anaerobic genera. All infants were colonized with high levels of Bifidobacterium except for one in each group. One to 5 Bifidobacterium species and 1 to 7 strains were observed per subject independently of allergic status and age at sampling. Our study showed the infants to be colonized by several species and strains, including several strains from the same species. This diversity in Bifidobacterium colonization was not related with the allergic status and showed that the link between Bifidobacterium colonization and allergic diseases is complex and cannot be restricted to the role attributed to Bifidobacterium species.     

Strategy for fluorescent labeling of human acidic fibroblast growth factor without impairment of mitogenic activity: A bona fide tracer

Here we describe, for the first time, the design and characterization of a bona fide fluorescently labeled mutant of the human acidic fibroblast growth factor (aFGF). The aFGF–Cys2 mutant was recombinantly synthesized by substituting the second amino acid with a reactive cysteine whose sulfhydryl group’s side chain reactivity facilitated the covalent binding of a fluorescent probe as a thiolyte monobromobimane. Using a combination of biophysical and functional assays, we found that the fluorescently labeled mutant aFGF is characterized by essentially the same global folding, mitogenic activity, and association behavior with heparin, its physiological activator, as the unlabeled wild-type protein. We used this new tracer protein mutant to determine the association behavior of aFGF with heparin in the presence of high concentrations of albumin that mimicked more closely the plasma medium in which aFGF is naturally located and in which it has evolved to function. By exposing the aFGF–Cys2–heparin complex to increasing concentrations of albumin up to physiological plasma levels, we were able to demonstrate that macromolecular crowding does not affect the stoichiometry of the interaction. In summary, the dimeric aFGF–Cys2–heparin complex might represent a biologically relevant complex in physiological media.     

Linfoma pulmonar primario no Hodgkin con infiltración de miocardio

A case of primary pulmonary non-Hodgkin's lymphoma is presented. On this occasion, the lymphoma invaded the myocardium, an event which has not previously been reported in the literature. These neoplasms spread by proximity, and invasion of the pericardium, thoracic wall and oesophagus have been described. Our patient died from heart failure. Tumour myocardial infiltration may well have been the determinant cause through various mechanisms, including a decrease in myocardial contractility. Spread into the myocardium may be facilitated by bulky tumour infiltrates in the pleural space.     

Paternally inherited markers in bovine hybrid populations

The genetic integrity of crossfertile bovine- or cattle-like species may be endangered by species hybridization. Previously, amplified fragment length polymorphism, satellite fragment length polymorphism and microsatellite assays have been used to analyze the species composition of nuclear DNA in taurine cattle, zebu, banteng and bison populations, while mitochondrial DNA reveals the origin of the maternal lineages. Here, we describe species-specific markers of the paternally transmitted Y-chromosome for the direct detection of male-mediated introgression. Convenient PCR-restriction fragment length polymorphism and competitive PCR assays are shown to differentiate the Y-chromosomes of taurine cattle, American bison and European bison, and to detect the banteng origin of Indonesian Madura and Bali cattle bulls.     

Independent sources of condition dependency and multiple pathways determine a composite trait: lessons from carotenoid‐based plumage colouration

Many colour ornaments are composite traits consisting of at least four components, which themselves may be more complex, determined by independent evolutionary pathways, and potentially being under different environmental control. To date, little evidence exists that several different components of colour elaboration are condition dependent and no direct evidence exists that different ornamental components are affected by different sources of variation. For example, in carotenoid‐based plumage colouration, one of the best‐known condition‐dependent ornaments, colour elaboration stems from both condition‐dependent pigment concentration and structural components. Some environmental flexibility of these components has been suggested, but specifically which and how they are affected remains unknown. Here, we tested whether multiple colour components may be condition dependent, by using a comprehensive 3 × 2 experimental design, in which we carotenoid supplemented and immune challenged great tit nestlings (Parus major) and quantified effects on different components of colouration. Plumage colouration was affected by an interaction between carotenoid availability and immune challenge. Path analyses showed that carotenoid supplementation increased plumage saturation via feather carotenoid concentration and via mechanisms unrelated to carotenoid deposition, while immune challenge affected feather length, but not carotenoid concentration. Thus, independent condition‐dependent pathways, affected by different sources of variation, determine colour elaboration. This provides opportunities for the evolution of multiple signals within components of ornamental traits. This finding indicates that the selective forces shaping the evolution of different components of a composite trait and the trait's signal content may be more complex than believed so far, and that holistic approaches are required for drawing comprehensive evolutionary conclusions.