Consequences of concurrent Ascaridia galli and Escherichia coli infections in chickens

   

Three experiments were carried out to examine the consequences of concurrent infections with Ascaridia galli and Escherichia coli in chickens raised for table egg production. Characteristic pathological lesions including airsacculitis, peritonitis and/or polyserositis were seen in all groups infected with E. coli. Furthermore, a trend for increased mortality rates was observed in groups infected with both organisms which, however, could not be confirmed statistically. The mean worm burden was significantly lower in combined infection groups compared to groups infected only with A. galli. It was also shown that combined infections of E. coli and A. galli had an added significant negative impact on weight gain.     

The evolutionary radiation of Arvicolinae rodents (voles and lemmings): relative contribution of nuclear and mitochondrial DNA phylogenies

Background  

Mitochondrial and nuclear genes have generally been employed for different purposes in molecular systematics, the former to resolve relationships within recently evolved groups and the latter to investigate phylogenies at a deeper level. In the case of rapid and recent evolutionary radiations, mitochondrial genes like cytochrome b (CYB) are often inefficient for resolving phylogenetic relationships. One of the best examples is illustrated by Arvicolinae rodents (Rodentia; Muridae), the most impressive mammalian radiation of the Northern Hemisphere which produced voles, lemmings and muskrats. Here, we compare the relative contribution of a nuclear marker – the exon 10 of the growth hormone receptor (GHR) gene – to the one of the mitochondrial CYB for inferring phylogenetic relationships among the major lineages of arvicoline rodents.     

The Effects of Mercury Compounds on the Growth and Orientation of Cucumber Seedlings

Mercuric chloride alone, in admixture with fluorescein or chemically combined as mercurochrome inhibited cucumber growth and induced disorientation of root and shoot. The inhibitory effects of Hg-ion were reduced but the disorienting (ageotropic) effects enhanced by the presence of fluorescein. In addition to mercury, nine other elements were tested at concentrations up to 100 mg/l (as metal ion). Disorientation was induced by Zn, Ag, Cd, In, Pt and Hg. Pb and Au were not toxic, but Ga and Tl were too inhibitory to permit disturbances in orientation.     

The novel ‘tongue‐bite apparatus’ in the knifefish family Notopteridae (Teleostei: Osteoglossomorpha): are kinematic patterns conserved within a clade?

Osteoglossomorph fishes are unique in possessing a specialized feeding mechanism, the tongue-bite apparatus (TBA) involving the hyoid apparatus. The TBA is associated with two unique behaviour patterns - raking and open-mouth chewing - used to disable and macerate prey. The kinematics of these two behaviours was compared in two species of knifefishes (family Notopteridae): Xenomystus nigri (Gunther, 1868) and Chitala ornata (Gray, 1831) using high-speed video (250 frames s"¹). Both univariate and multivariate analyses indicated that there were significant interspecific differences in both raking and open-mouth chewing. Raking can be divided into three stages; the preparatory phase, power stroke, and recovery phase. During the power stroke posterior motion of the pectoral girdle and neurocranial elevation both appear to play a major role in prey reduction. In Xenomystus the power stroke involves significantly greater levels of neurocranial elevation (35^o) and pectoral girdle motion (38% of head length; 9.5^o) than that found in Chitala (neurocranial elevation 11^o; pectoral girdle motion 11% of head length and 5^o). Indeed, Xenomystus represents the most extreme raking behaviour of any osteoglossomorph thus far studied. Temporal displacement variables demonstrated that the power stroke in Xenomystus is significantly faster than in Chitala. Although some of the interspecific differences might be size related, these data suggest that a greater degree of difference exists in these highly specialized behaviours than previous work has demonstrated. These findings support the notion that biomechanical duplication (an additional ligament found in osteoglossomorphs) could be linked to increased functional versatility.     

Anthropologies of Violence and Resistance

Encounters with Violence in Latin America: Urban Poor Perceptions from Colombia and Guatemala. Caroline O. N. Moser and Cathy McIlwaine. New York: Routledge, 2004. 272 pp.
Violence: Theory and Ethnography. Pamela J. Stewart and Andrew Strathern. New York: Continuum, 2002. 196 pp.
Shadows of War: Violence, Power, and International Profiteering in the Twenty-First Century. Carolyn Nordstrom. Berkeley: University of California Press, 2004. 293 pp.     

The abundance of additional N-acetyllactosamine units in N-linked tetraantennary oligosaccharides of human Tamm-Horsfall glycoprotein is a donor-specific feature

Previously, treatment of Tamm-Horsfall glycoprotein (THp) from different donors with endo-beta-galactosidase has been shown to liberate a tetra- and a Sd(a)-active pentasaccharide, concluding the presence of N-linked carbohydrate chains containing additional N - acetyllactosamine units. These type of oligosaccharides were not found in a detailed structure elucidation of the carbohydrate moiety of THp of one male donor, suggesting a donor-specific feature for these type of structures. Therefore, THp was isolated from four healthy male donors and each subjected to endo-beta-galactosidase treatment in order to release these tetra- and Sd(a)-active pentasaccharide. Differences were observed in the total amount of released tetra- and Sda-active pentasaccharide of the used donors (42, 470, 478, 718 microg/100 mg THp), indicating that the presence of repeating N-acetyllactosamine units incorporated into the N-glycan moiety of THp is donor specific. Furthermore, a higher expression of the Sd(a) determinant on antennae which display N-acetyllactosamine elongation was observed, suggesting a better accessibility for the beta-N-acetylgalactosaminyltransferase. In order to characterize the N-glycans containing repeating N- acetyllactosamine units, carbohydrate chains were enzymatically released from THp and isolated. The tetraantennary fraction, which accounts for more than 33% of the total carbohydrate moiety of THp, was used to isolate oligosaccharides containing additional N - acetyllactosamine units. Five N-linked tetraantennary oligosaccharides containing a repeating N-acetyllactosamine unit were identified, varying from structures bearing four Sd(a) determinants to structures containing no Sd(a) determinant (see below). One compound was used in order to specify the branch location of the additional N- acetyllactosamine unit, and it appeared that only the Gal-6' and Gal-8' residues were occupied by a repeating N -acetyllactosamine unit.      

Differential binding of lectins IL-2 and CSL to candida albicans and cancer cells

The demonstration that interleukin 2 (IL-2) is a lectin specific for oligomannosides allows to understand a new function for this cytokine: as a bifunctional molecule when bound to its receptor ss, IL-2 associates the latter which the CD3/TCR complex, interacting with oligosaccharides of CD3 through its carbohydrate-recognition domain (Zanetta et al. , 1996, Biochem. J., 318, 49-53). This induces the tyrosine phosphorylation of the IL-2R beta by ++p56(lck) , the first step of the IL-2-dependent signaling. Since this specific association is disrupted in vitro by oligomannosides with five and six mannose residues, we made the hypothesis that pathogenic cells or microorganisms could bind IL-2, consequently disturbing the IL-2- dependent response. This study shows that the pathogenic yeast Candida albicans (in contrast with nonpathogenic yeasts) binds high amounts of IL-2 as did cancer cells. In contrast with cancer cells, yeasts do not bind the Man6GlcNAc2-specific lectin CSL, an endogenous "amplifier of activation signals" (Zanetta et al. , 1995, Biochem. J., 311, 629-636).