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941.
A. Costagliola D. Russo A. A. Izzo P. Urbani V.
di
Marzo A. Cecio 《Anatomia, histologia, embryologia》2005,34(Z1):13-13
The endocannabinoid anandamide may regulate intestinal motility through activation of CB1 receptors. Anandamide is then inactivated by fatty acid amide hydrolase (FAAH), a membrane bound enzyme. Under pathological conditions, inactivation of such enzymatic activity may lead to inhibition of the intestinal motility. Here, preliminary reports on the distribution of Fatty Acid Amide Hydrolase (FAAH) immunoreactivity in the mouse gastrointestinal neurons, and the pharmacological effects of N‐arachidonoylserotonin (AA‐5HT), a selective inhibitor of FAAH, are reported. FAAH was revealed by an indirect immunofluorescence. Laminar preparations containing the myenteric or the submucous plexus adhered, were peeled off after the whole gut wall had been stretched out and fixed in 4% paraformaldehyde. They were subsequently incubated with a polyclonal anti‐serum directed against a region near the N‐terminus of the human FAAH and revealed by a FITC‐conjugated goat anti‐rabbit secondary anti‐serum. FAAH‐immunoreactive neurons were observed within the myenteric ganglia throughout the GIT. The positive nerve cells varied in size and density of immunoreactivity. Stomach and large intestine showed the highest neuronal density. AA‐5HT significantly reduced both gastric emptying and gastrointestinal tract transit. Such inhibitory effect was reduced by the C1 receptor antagonist SR141716A. Both morphological and pharmacological results suggest that FAAH may play a critical role in controlling gut anandamide levels. 相似文献
942.
H. Neubauer L. D. Sprague R. Zacharia H. Tomaso S. Al Dahouk R. Wernery U. Wernery H. C. Scholz 《Zoonoses and public health》2005,52(5):201-205
Burkholderia mallei causes glanders or farcy in solipeds, a disease that must be reported to the OIE (Office International des Epizooties, Paris, France). The number of reported outbreaks has increased steadily during the last decade. Serodiagnosis is hampered by the considerable number of false‐positives and ‐negatives of the internationally prescribed tests. The major problem leading to low sensitivity and specificity of complement fixation test (CFT) and enzyme‐linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e. crude preparations of whole cells. Future perspectives for the development and evaluation of serological test kits using well‐characterized single antigens are discussed in the light of recent molecular research on B. mallei and the closely related saprozoonotic agent B. pseudomallei. 相似文献
943.
Most mammals have two different structures in which we found glomerular layers at the same time: the main olfactory bulb (MOB) and the accessory olfactory bulb (AOB). Both bulbs have the same pattern of organization, but there are some differences: although the size is considerably bigger in MOB than in AOB, probably the most important difference is that the principal cells are not differentiated into mitral and tufted cells in the AOB, and are usually described as mitral/tufted cells. We have previously observed that in some mammals, like pigs and sheep, the AOB reaches maturity before birth, but this is not a rule for other species. Surprisingly, mice need several days of life to achieve full stratification of its cellular components. We have studied the chronology of this process, focusing our attention on the glomerular layer, the last to appear. We concluded that there are two critical periods, between E11.5 and E16.5 (migration phase) and between E17.5 and P3.5–7 (true morphological constitution). 相似文献
944.
The influence of sampling scheme and interpolation method on the power to detect spatial effects of forest birds in Ontario (Canada) 总被引:1,自引:0,他引:1
Spatial ecology is becoming an increasingly important component of resource management, and the general monitoring of how
human activities affect the distribution and abundance of wildlife. Yet most work on the reliability of sampling strategies
is based on a non-spatial analysis of variance paradigm, and little work has been done assessing the power of alternative
spatial methods for creating reliable maps of animal abundance. Such a map forms a critical response variable for multiple
scale studies relating landscape structure to biotic function. The power to reconstruct patterns of distribution and abundance
is influenced by sample placement strategy and density, the nature of spatial auto-correlation among points, and by the technique
used to extrapolate points into an animal abundance map. Faced with uncertainty concerning the influence of these factors,
we chose to first synthesize a model reference system of known properties and then evaluate the relative performance of alternative
sampling and mapping procedures using it. We used published habitat associations of tree nesting boreal neo-tropical birds,
a classified habitat map from the Manitou Lakes area of northwestern Ontario, and point count means and variances determined
from field studies in boreal Canada to create 4 simulated models of avian abundance to function as reference maps. Four point
sampling strategies were evaluated by 4 spatial mapping methods. We found mixed-cluster sampling to be an effective point
sampling strategy, particularly when high habitat fragmentation was avoided by restricting samples to habitat patches >10
ha in size. We also found that of the 4 mapping methods, only stratified ordinary point kriging (OPK) was able to generate
maps that reproduced an embedded landscape-scale spatial effect that reduced nesting bird abundance in areas of higher forest
age-class fragmentation. Global OPK was effective only for detecting broader, regional-scale differences.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
945.
946.
Assessing the potential impacts of alternative landscape designs on amphibian population dynamics 总被引:2,自引:1,他引:2
An individual-based, spatially explicit population model was used to predict the consequences of future land-use alternatives for populations of four amphibian species in two central Iowa (midwest USA) agricultural watersheds. The model included both breeding and upland habitat and incorporated effects of climatic variation and demographic stochasticity. Data requirements of the model include life history characteristics, dispersal behavior, habitat affinities, as well as land use and landcover in geographic information systems databases. Future scenarios were ranked according to change in breeder abundance, saturation, and distribution, compared to baseline conditions. Sensitivity of simulation results to changes in model parameters was also examined. Simulated results suggest that while all four species modeled are likely to persist under present and future scenario conditions, two may be more at risk from future landscape change. Although the study species are all widespread generalists regarded as having a low conservation priority, they depend on wetlands and ponds, increasingly endangered habitats in agricultural landscapes. Broader conservation strategies in the region would ensure that these currently common organisms do not become the endangered species of the future.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
947.
P. Nicholson A.S. Turner S.G. Edwards G.L. Bateman L.W. Morgan D.W. Parry J. Marshall M. Nuttall 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(2):163-177
The progress of development of stem-base pathogens in crops of second winter wheat was plotted in nine experiments in three years. The amount of each pathogen present was determined by quantitative PCR. Where Tapesia yallundae was present in quantifiable amounts, it usually developed earlier than the other eyespot pathogen, T. acuformis. Both species were usually present in greater amounts on cultivars which are more susceptible to eyespot. The sharp eyespot pathogen, Rhizoctonia cerealis, developed more erratically than either of the Tapesia spp. and there were no consistent effects on different cultivars. Fusarium spp., the cause of brown foot rot, were rarely present in quantifiable amounts, but Microdochium nivale was usually present as one or both of the varieties nivale and majus. Late-season (after anthesis) decreases in M. nivale suggest that any brown foot rot symptoms attributable to this fungus would have fully developed earlier. Cultivar differences in amounts of M. nivale were most clear in stems during internode extension and when relatively large amounts of DNA were present. Such differences approximately reflected eyespot susceptibility, cv. Soissons containing most and cv. Lynx containing least DNA. The results emphasise the difficulty in relating diagnoses, by quantitative PCR or other means, at early growth stages when decisions to apply fungicides against stem-base disease are made, to later disease severity. 相似文献
948.
P. Galeffi G. Giunta S. Guida C. Cantale 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(5):479-483
Citrus tristeza virus (CTV) is one of the most destructive citrus virus diseases in the world. The construction of an engineered antibody, EMBL accession number AJ278109, able to specifically recognize its antigen, i.e. the coat protein of CTV, directly on infected plant material without any purification or manipulation of the entire woody plant. The potential uses of this engineered antibody are discussed. 相似文献
949.
Kazuhiko Narisawa Hitoshi Kawamata Randolph S. Currah Teruyoshi Hashiba 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(2):103-109
One hundred and twenty-three fungal isolates were obtained from 225 root segments of eggplants, melon, tomato, strawberry and Chinese cabbage, grown as bait plants in a mixed soil made up of samples from different fields in Shizuoka, Japan. Isolates belonging to Mycelium radicis atrovirens (MRA), including Phialocephala fortinii, were the most prevalent in all the five bait plants. Eleven of the 123 isolates, after being inoculated onto axenically reared eggplant seedlings, almost completely suppressed the pathogenic effects of a post-inoculated, virulent strain of Verticillium dahliae. Seven of these 11 isolates had come from the roots of eggplant and included Heteroconium chaetospira,
P. fortinii, and unidentified species of Fusarium, Penicillium, Trichoderma and MRA. P. fortinii, H. chaetospira, a non-sporulating isolate with white mycelium (SWM) and MRA were easily reisolated from root segments. Hyphae of H. chaetospira, P. fortinii and SWM colonized the root tissues of eggplant without causing apparent pathogenic symptoms. The mechanisms by which these endophytes confer resistance to infection by V. dahliae are unknown but the effectiveness of these fungi in a laboratory setting indicates that they have potential as biocontrol agents and merit further investigation. 相似文献
950.
Growth and reproduction by powdery mildew pathogens is generally inhibited by decreasing relative humidity. With Erysiphe sp. on Rhododendron cv. Elizabeth, the initial stages of colony development were adversely affected by reducing the relative humidity from 100% to 70 and 85%. No significant effects on secondary or tertiary hyphal development were detected. Light intensity and photoperiod both had considerable effect on the induced resistance response of the host. Over the initial 5 days of colonization there were no significant differences between any of the treatments. After 13 days, however, expansion of fungal colonies at 180 photosynthetic active radiation (PAR) was limited solely to the area initially infested by primary hyphae. By comparison, in colonies grown at 80 PAR regardless of day length, secondary and tertiary hyphae had extended beyond the area first colonized. These effects resulted in differing morphologies, small colonies of densely packed hyphae formed at 180 PAR compared with open spreading colonies at 80 PAR. 相似文献