Search results for "Rodent"
showing 10 items of 199 documents
Stereoselective Synthesis of Enantiomerically Pure Nupharamine Alkaloids from Castoreum
2009
An animalic note: The first total synthesis of the all-cis nupharamine 2, an alkaloid from beaver castoreum, is based on the stereoselective domino Mannich-Michael reaction of N-galactosylfurylaldimine to give 1 (Piv = pivaloyl), subsequent conjugate cuprate addition, and stereoselective protonation of the enolate. These reactions are all controlled by the carbohydrate. Protonation of the enolate after cleavage of the auxiliary leads to epimer 3.
Who eats first? Uptake of pellet bait by target and non-target species
2002
House mice (Mus domesticus) are an important vertebrate pest in Australian agriculture. We studied the uptake of non-toxic placebo bait pellets targeted on house mice from bait stations in the grain-growing region of southeastern Australia. Bait stations allowed access for either ants; ants and mice or ants, mice, and birds. Soy meal bait pellets offered in December were of low preference for both ants and mice, but were eaten by birds in one study plot. In January, there were no differences between bait stations in the amount of wheat bait pellets removed indicating that the pellet bait had been primarily removed by ants. Most pellet bait was removed during the first 12 h after distributio…
Body size increase in insular rodent populations: A role for predators?
2002
Insular mammalian populations living in areas of small size are often characterized by a drastic change in body mass compared to related continental populations or species. Generally, small mammals (less than 100 g) evolve into giant forms while large mammals (up to 100 g) evolve into dwarf forms. These changes, coupled with changes in other life, behavioural, physiological or demographic traits are referred to generally as the insular syndrome. We tested in this study the relative contribution of three factors - area of island, numbers of competitor species and number of predator species - to changes in body size of the woodmouse (Apodemus sylvaticus) in the Western Mediterranean Sea. Our …
Lagomorpha (Rabbits, Hares and Pikas)
2001
Lagomorphs comprise the pikas, hares and rabbits. The members of this order have a head and body length between 0.125 and 0.75 m, and adults weigh from 0.1 to 5 kg. All are terrestrial. Pikas are mostly diurnal whereas rabbits and hares are active mainly in the evening and night. They can be strong runners. Keywords: lagomorphs; rabbit; hare; pika; teeth; rodent; ecology; evolution
New insular taxa from the oldest Terre Rosse fissure filling (Gargano, Southeastern Italy).
2012
A rich amount of fossil remains of a highly diversified vertebrate fauna, known as “Mikrotia fauna”, has been retrieved from the red soil deposits (Terre Rosse) which fill the extensive palaeokarst network that affects the Mesozoic limestone along the north-western slopes of Mount Gargano (Southern Italy). The faunal assemblages reveal a rather complex history of bioevents such as dispersals and extinctions, which occurred when the area was isolated. These reconstructions were based on the materials collected during the seventies and the eighties of the last century. Forty years after its discovery, the Gargano Terre Rosse finally yielded evidence of an older faunal settlement. The peculiar…
Parental experience of a risky environment leads to improved offspring growth rate.
2014
Abstract Parasites (or diseases) are major selective force for the evolution of life history traits and parasite-host evolution. Mothers can show a variety of responses to parasites during pregnancy with different consequences for them or their offspring. However, whether information in the maternal environment before pregnancy can cause a change in the phenotype of the offspring is unknown. To avoid the confounding effect of pathogens and to reduce the risk of direct effect of mother's immune activation, we injected female laboratory mice with lipopolysaccharides (LPS) before mating. In order to provide a constant information on the potential infectious risk of the environment, females wer…
Pivotal advance: alpha-galactosylceramide induces protection against lipopolysaccharide-induced shock.
2007
Abstract α−galactosylceramide, a natural killer T cell ligand, and its synthetic homolog, KRN7000, consistently influence IFN-γ and TNF-α release, both mediators of LPS-induced shock. To modify the course of endotoxin shock, we injected KRN7000 at different time points of experimental systemic Shwartzman reaction. Mice treated with KRN7000 survived when it was injected within 2 h before and after LPS challenge. Mice survival was associated with low levels of T helper 1 (Th1) cytokines, such as IFN-γ and TNF-α. By contrast, protection from endotoxin shock was associated with an increase of T helper 2 (Th2) cytokines, like IL-4 and IL-10. A role of Th2 cytokines in counteracting LPS-induced s…
Prophylaxis of lipopolysaccharide-induced shock by α-galactosylceramide
2008
AbstractThe NKT cell ligand α-galactosylceramide and its synthetic homologue KRN7000 stimulate rapid and copious secretion of IFN-γ and TNF-α release, both of which are key mediators of LPS-induced shock. We showed that KRN7000, injected before or within 2 h after LPS challenge, was able to prevent endotoxic shock. KRN7000 induced survival when the mice were injected 6, 9, or 12 days before the first injection of LPS, and this protective effect was associated with reduction upon subsequent challenge in the levels of IFN-γ, TNF-α, MCP-1, and an increase of IL-10. Further analysis showed that the animals treated with KRN7000 prior to LPS challenge had lower numbers of F4/80+, NKT, and NK cell…
The effects of Borrelia infection on its wintering rodent host
2022
AbstractIn seasonal environments, appropriate adaptations are crucial for organisms to maximize their fitness. For instance, in many species, the immune function has been noticed to decrease during winter, which is assumed to be an adaptation to the season’s limited food availability. Consequences of an infection on the health and survival of the host organism could thus be more severe in winter than in summer. Here, we experimentally investigated the effect of a zoonotic, endemic pathogen, Borrelia afzelii infection on the survival and body condition in its host, the bank vole (Myodes glareolus), during late autumn–early winter under semi-natural field conditions in 11 large outdoor enclos…
Differences in cell proliferation in rodent and human hepatic derived cell lines exposed to ciprofibrate.
2005
International audience; Humans appear to be refractory to some effects of peroxisome proliferators including alterations in cell proliferation, whereas rodents are susceptible. In this study, differences between the human and rat response to peroxisome proliferators were evaluated using rat and human tumour liver cell lines. Rat 7777 cells were more responsive than human HepG2 cells to ciprofibrate as they exhibited a higher decrease in cell number than HepG2, and underwent apoptosis. Results from these studies reveal a surprising response in tumour cell lines as the typical in vivo response of increased cell proliferation and reduced apoptosis was not observed in rat tumour cell lines at c…