7 research outputs found
Amphetamine-induced taste aversion learning in young and old F-344 rats following exposure to 56Fe particles
Exposure to 56Fe particles produces changes in dopaminergic function and in dopamine-dependent behaviors, including amphetamine-induced conditioned taste aversion (CTA) learning. Because many of these changes are characteristic of the changes that accompany the aging process, the present study was designed to determine whether or not there would be an interaction between age and exposure to 56Fe particles in the disruption of an amphetamine-induced CTA. One hundred and forty F-344 male rats 2-, 7-, 12-, and 16-months old, were radiated with 56Fe particles (0.25â2.00Â Gy, 1Â GeV/n) at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for the effects of radiation on the acquisition of a CTA produced by injection of amphetamine (3Â mg/kg, i.p.). The main effect of age was to produce a significant decrease in conditioning day sucrose intake; there was no affect of age on the acquisition of the amphetamine-induced CTA. Exposing rats to 56Fe particles disrupted the acquisition of the CTA produced by injection of amphetamine only in the 2-month-old rats. These results do not support the hypothesis of an interaction between age and exposure to 56Fe particles in producing a disruption of amphetamine-induced CTA learning. As such, these results suggest that the aging produced by exposure to 56Fe particles may be endpoint specific
Modulation of immune responses by targeting CD169/Siglec-1 with the glycan ligand
A fundamental role in the plant-bacterium interaction for
Gram-negative phytopathogenic bacteria is played by membrane
constituents, such as proteins, lipopoly- or lipooligosaccharides
(LPS, LOS) and Capsule Polysaccharides (CPS).
In the frame of the understanding the molecular basis of plant bacterium interaction, the Gram-negative bacterium Agrobacterium vitis was selected in this study. It is a phytopathogenic member of the Rhizobiaceae family and it induces the crown gall disease selectively on grapevines (Vitis vinifera).
A. vitis wild type strain F2/5, and its mutant in the quorum
sensing gene ÎaviR, were studied. The wild type produces biosurfactants; it is considered a model to study surface motility, and it causes necrosis on grapevine roots and HR (Hypersensitive
Response) on tobacco. Conversely, the mutant does not show any
surface motility and does not produce any surfactant material;
additionally, it induces neither necrosis on grape, nor HR on
tobacco. Therefore, the two strains were analyzed to shed some
light on the QS regulation of LOS structure and the consequent
variation, if any, on HR response. LOS from both strains were isolated and characterized: the two LOS structures maintained several common features and differed for few others.
With regards to the common patterns, firstly: the Lipid A region
was not phosphorylated at C4 of the non reducing glucosamine
but glycosylated by an uronic acid (GalA) unit, secondly: a third
Kdo and the rare Dha (3-deoxy-lyxo-2-heptulosaric acid) moiety
was present.
Importantly, the third Kdo and the Dha residues were substituted
by rhamnose in a not stoichiometric fashion, giving four different
oligosaccharide species.
The proportions among these four species, is the key difference
between the LOSs from both the two bacteria.
LOS from both strains and Lipid A from wild type A. vitis are
now examined for their HR potential in tobacco leaves and grapevine roots