1,440 research outputs found
Efficacy of amphotericin B and fluconazole in the murine mycotie (Candida albicans) mastitis model
The majority of animal models in antifungal tests use systemic infection and mortality and survival of infected animals as the experimental end—point. We developed a murine model of localised eandidiasis (murine myeotic mastitis) and assessedits effectiveness through infection with Candida albicans followed by intraperitoneal administration of the antifungal drugs flunazole (FLU) and amphotericin B (AmB). Lactating BALB/cJ mice at day 5 post partum were inoculated (two glands) with a high dose of a human pathogenic C. albicans wild-type strain SC5314. Animals were treated immediately after infection with either FLU or AmB intraperitoneally for 4 days and euthanized by intracardiae exsanguination and cervical dislocation following anaesthesia with a mixture of Ketamine arid Xylazine. One infected gland was fixed in formalin and examined histopathologically and the other was homogenised for quantitative fungal cultures. There were severe changes in the untreated control animals (some animals had systemic candidiasis) compared to the treatment groups which had milder lesions. Fungal burden, determined as log [colony forming units (CFU)/g of mammary gland tissue], was similar in the untreated control group (n = 10) and FLU treated group (n = 6). However, there was significantly lower CFU/g in the mammary glands in AmB treated animals (n : 6) compared to both control and FLU treated animals (p < 0.05). The results indicate that AmB is more effective in prevention of murine mycotic mastitis than FLU and that the murine mycotic mastitis model may be an attractive animal model for antifungal chemotherapy studies
Cell mediated immune response dominates in experimental mammary gland Candida krusei infection in immunocompetent and immuno - compromised (nu/nu) mice
Experimental local mammary gland Candida krusei infection in immuno-competent and in congenic athymie nude BALB/c mice over a period of 21 days demonstrated that the immunocompetent mice readily cleared the infection whereas the infection persisted in the athymic mice. The fungal burden, however, was similar in the nude mice and in the immuno-compctcnt mice until day 18 after infection. The ratio Ofinterferony/interleukin-4 (1FN-y/IL-4) concentrations in supernatants from (ZonA stimulated splenocytcs of the infected mice indicated a predominant Th1 response to the C. krusei infection. Stimulated splenocytes of the infected immuno-competent mice synthesised significantly higher concentrations of the two eytokines than did the splenocytes from the infected nude mice. The present study indicates that local C. krusei infection is associated with a predominant IFN-y-Th1 response although a gradual activation of the Th2 -arm (IL-4) of the immune system may beindicated late in the course of infection
Off equilibrium magnetic properties in a model for vortices in superconductors
We study the properties of a simple lattice model of repulsive particles
diffusing in a pinning landscape. The behaviour of the model is very similar to
the observed physics of vortices in superconductors. We compare and discuss the
equilibrium phase diagram, creep dynamics, the Bean state profiles, hysteresis
of magnetisation loops (including the second peak feature), and, in particular,
``off equilibrium'' relaxations. The model is analytically tractable in replica
mean field theory and numerically via Monte Carlo simulations. It offers a
comprehensive schematic framework of the observed phenomenology
The prisoners dilemma on a stochastic non-growth network evolution model
We investigate the evolution of cooperation on a non - growth network model
with death/birth dynamics. Nodes reproduce under selection for higher payoffs
in a prisoners dilemma game played between network neighbours. The mean field
characteristics of the model are explored and an attempt is made to understand
the size dependent behaviour of the model in terms of fluctuations in the
strategy densities. We also briefly comment on the role of strategy mutation in
regulating the strategy densties.Comment: 8 pages, 8 figure
The Distribution Pattern of \u3cem\u3eHalicephalobus gingivalis\u3c/em\u3e in a Horse is Suggestive of a Haematogenous Spread of the Nematode
The majority of Halicephalobus gingivalis-infections in horses have been fatal and are usually not diagnosed before necropsy. Therefore, knowledge about the nematode and the pathogenesis of infection in horses is limited. This has resulted in an on-going discussion about the port of entry and subsequent dissemination of H. gingivalis within the host. The present case of H. gingivalis-infection in a horse was diagnosed ante mortem. Post mortem findings, the distribution pattern of H. gingivalis nematodes in the brain, a high prevalence of inflammation in close relation to blood vessels, and the presence of the nematode in multiple organs with a disseminated pattern of distribution strongly suggested a haematogenous spread of the nematode in the horse
Histologic and bacteriologic findings in valvular endocarditis of slaughter-age pigs
Endocarditis lesions from 117 slaughter pigs were examined pathologically and etiologically in addition to 90 control hearts with cardiac valves. Lesions were located on the valves; however, the lesions had extended to the walls in 21 cases (18%). Lesions predominated on the mitral valve (59%). A total of 28 cases, from which no growth was obtained or a contamination flora was grown, were screened by fluorescence in situ hybridization (FISH) for bacteria (general bacterial probe) and probes specific for Streptococcus suis and Erysipelothrix rhusiopathiae, respectively. Using FISH, an additional 10 cases of endocarditis due to S. suis and E. rhusiopathiae were disclosed. Within lesions, streptococci predominated (53%) followed by E. rhusiopathiae (30%). Distinct features of both the lesions and the shape and localization of bacterial colonies were related to streptococci and E. rhusiopathiae. The propensity for streptococci to be localized on more than 1 valve in single hearts may be because S. suis–infected pigs tend to have been infected for a longer period compared with E. rhusiopathiae. Mineralization of endocarditis lesions was significantly associated with infection by streptococci, and was seen in 71% of the cases, whereas it was present in only 28% of lesions caused by E. rhusiopathiae. In addition, areas with mineralization were significantly correlated to the presence of a granulomatous reaction. Granulomatous endocarditis is likely a result of a foreign body reaction due to dystrophic mineralization. Local proliferation of valvular endothelial cells, found in 9 hearts in the current study, may increase the risk of developing thrombosing endocarditis in pigs. </jats:p
Elastic Chain in a Random Potential: Simulation of the Displacement Function and Relaxation
We simulate the low temperature behaviour of an elastic chain in a random
potential where the displacements are confined to the {\it longitudinal}
direction ( parallel to ) as in a one dimensional charge density
wave--type problem. We calculate the displacement correlation function and the size dependent average square displacement
. We find that with
at short distances and at intermediate
distances. We cannot resolve the asymptotic long distance dependence of
upon . For the system sizes considered we find with . The exponent is in agreement
with the Random Manifold exponent obtained from replica calculations and the
exponent is consistent with an exact solution for the chain
with {\it transverse} displacements ( perpendicular to ).The
distribution of nearest distances between pinning wells and chain-particles is
found to develop forbidden regions.Comment: 19 pages of LaTex, 6 postscript figures available on request,
submitted to Journal of Physics A, MAJOR CHANGE
Grain legume–cereal intercropping systems
Chapitre 11Grain legume–cereal intercropping system
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