Specific hybridization real‐time PCR probes for Phytophthora ramorum detection and diagnosis

Sudden Oak Death, caused by Phytophthora ramorum, poses a serious threat to native American oaks, and is also present in Europe where it has been isolated from numerous European ornamental plant nurseries. Its proven aggressiveness against plants in the Fagaceae and Ericaceae and the damage it has caused in North America have lead to it being assigned quarantine status. The timely and accurate detection of P. ramorum is a critical aid in the study of the epidemiology and biology of this pathogen. As a regulated organism, the availability of a sensitive and reliable assay is essential when attempting to achieve early detection of the pathogen. In this work, new specific hybridization probes for a real‐time PCR amplification method were found to be rapid, robust and labour‐saving, and proved suitable for routine use in a molecular diagnostic laboratory.     

Estimations of daily energy and nutrient availability based on nationally representative household budget survey data. The Data Food Networking (DAFNE) project

OBJECTIVE: To describe a cost-efficient method for estimating energy and nutrient availability using household budget survey (HBS) data. DESIGN: Four different approaches were tested and the results were compared with published nutrient intake data. The selected method was exemplarily applied in German and Greek data. SETTING: Germany, 1998; Greece, 1998/99. MATERIAL: Nationally representative HBSs. RESULTS: Comparisons showed that HBS-based estimates were generally close to intake data when results were presented as contributions to daily energy intake. Daily energy and protein availabilities were similar in Germany and Greece. Differences were observed in the availability of carbohydrates (German households reported a 5 percentage points higher contribution to daily energy availability) and lipids (Greek households recorded higher values for total fat, but lower values for saturated fat). Meat, added lipids and potatoes were important energy suppliers in Germany, whereas in Greece the first three energy suppliers were added lipids, cereals and meat. In both countries, meat, cereals, milk and cheese were important protein sources and cereals, potatoes, fruits and nuts contributed more than 60% of the daily carbohydrate availability. Added lipids were the major source of fat in the daily diet of both countries, but their contribution amounted to less than one-third in Germany and two-thirds in Greece. CONCLUSIONS: National HBS data can be used for monitoring and comparing nutrient availability among representative population samples of different countries. The ground is set for the development of a harmonised food composition table to be applied to HBS food data at international level.     

Comparative trials of four probes for obtaining rumen fluid from adult cattle with regard to saliva flow into the aspirated sample

Four probes for the acquisition of rumen fluid in adult cattle were tested with regard to their usefulness (pump capacity): probe I = original instrument of Schambye-S?rensen, probe II = modified Schambye-S?rensen instrument, probe III = guidable instrument of Dirksen, probe IV = a simple "home made" plastic instrument with a metal suction head. In a first step bovine saliva was added in increasing quantities (in increments of 5% up to 50%) to normal rumen fluid samples collected via rumen fistula. Some relevant parameters of the rumen fluid were analyzed with these mixtures. The experiments were carried out in order to obtain data for the calculation of saliva inflow in samples collected by orally introduced probes. In a second step a sample of rumen fluid was aspirated from the ventral rumen sac via the fistula before each introduction of the rumen sound. Saliva inflow was calculated on the basis of the in vitro changes in pH and in Na+ and K+ concentrations noted with each 5% addition of saliva. Results: The pH value increased with the addition of saliva more markedly for samples with a lower initial value. The sodium concentration in the rumen fluid increased almost linearly by an average of 2.5 mmol/l, while potassium concentration decreased by approximately 1.4 mmol/l with each 5% increase of saliva. Chloride concentration of the physiologic rumen fluid was essentially unaffected by addition of saliva (up to 30%). The methylene blue reaction was slightly enhanced by admixture of 5 to 10% saliva and prolonged by greater volumes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response

In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.     

Interferon-gamma, interleukin-4 and interleukin-10 production by T helper cells reveals intact Th1 and regulatory TR1 cell activation and a delay of the Th2 cell response in equine neonates and foals

Cytokines produced by T helper (Th) cells are important in orchestrating the immune response during health and disease. Recent reports indicated that cytokine mRNA expression in foals is often quantitatively lower than that of adult horses suggesting that foal T cells are not fully mature. Here, peripheral blood mononuclear cells from foals and adult horses were stimulated with phorbol 12-myristate 13-acetate and analyzed for intracellular interferon-gamma (IFN-γ), interleukin-4 (IL-4) and IL-10 production, representing the Th1, Th2 and regulatory T_R1 cell phenotypes respectively, by flow cytometry. In agreement with previous reports, all three cytokines were quantitatively reduced in foals compared to adults. However, the balance between Th1 and Th2 cytokines (IFN-γ/IL-4 ratio) showed a clear Th1-biased response in foals by 6 and 12 weeks of life, while similar IFN-γ/IL-10 ratios were found in foals and adult horses. By day 5 after birth, intracellular IFN-γ production by foal CD4⁺ and CD8⁺ T cells resembled that in adults. Overall, IL-4 production was low in foals. IL-4⁺ cells peaked at day 5 of age when IL-4 was mainly produced by IgE⁺ cells. Relative percentages of IL-4⁺ Th2 cells were significantly lower in foals at all time points. The data suggested that equine neonates and young foals have an impaired Th2 response, that the immune response of foals is Th1 biased, that IFN-γ production by Th and cytotoxic T cells is qualitatively similar to adult horses, and regulatory IL-10 production by T cells is developmentally mature in foals during the first three months of life.     

Depression of polymorphonuclear leukocyte function associated with experimentally induced Escherichia coli mastitis in sows

In a study of susceptibilities of sows from 2 herds to experimentally induced Escherichia coli mastitis, a marked difference was seen. The "susceptible" sows were from a conventional herd and "resistant" sows were from a specific-pathogen-free herd. The purpose of the study was to determine whether deficient neutrophil function was associated with increased susceptibility to E coli-induced mastitis. Four in vitro procedures were used to evaluate polymorphonuclear leukocyte (PMN) function: (i) random migration under agarose, (ii) ingestion of 125I-iododeoxyuridine-labeled Staphylococcus aureus, (iii) quantitative nitroblue tetrazolium reduction, and (iv) iodination. After parturition and intramammary inoculation with E coli, sows from the susceptible herd were neutropenic and the neutrophils which were present in the peripheral blood had reduced function. Specifically, there were depressed random migration under agarose, S aureus ingestion, and iodination when compared with PMN function in resistant sows. These data indicate that susceptibility to E coli mastitis was associated with deficiencies in PMN numbers and function. Potential causes of the neutrophil dysfunction are discussed and include possible systemic hormonal aberrations or the presence of an inapparent viral or bacterial infection.     

Naturally acquired enteric adenovirus infection in Syrian hamsters (Mesocricetus auratus)

Intranuclear inclusions indicative of adenovirus infection were detected microscopically in formalin-fixed intestinal tissues from preweanling Syrian hamsters. The amphophilic intranuclear inclusion bodies were observed in ileal enterocytes from 16-to 24-day-old hamsters. Electron microscopy revealed large numbers of 72 +/- 3-nm viral particles typical of adenoviridae in enterocytic nuclei. Serum antibodies reacted with mouse adenovirus strains K87 and, to a lesser extent, FL, by indirect fluorescent antibody testing. Clinical disease was not associated with the adenoviral infections. Hamsters from 10 production colonies, including all major commercial Syrian hamster suppliers in the United States, were surveyed and all had serologic or histopathologic evidence of adenovirus infection.     

Die Ertragsbildung und Ertragsstruktur eines konventionellen und eines epigonalen Genotyps der Weißen Lupine (Lupinus albus)

Yield formation and yield components of a conventional and an epigonal genotype of white lupin ( Lupinus albus )
Differences in yield formation and yield structure of two contrasting Lupinus albus growth types, the conventional, freely branching cultivar Kalina and the epigonal. little branching cultivar Ep I were analyzed. Both cultivars were grown in field experiments at Hohenheim in 1987 and 1988 with a combined variation of population density (30–120 plants/m²) and plant distribution. In addition, assimilate distribution within the plant was studied using a ¹⁴C-labelling experiment. – The contributions of branches to light interception of the crops during the generative phase were > 90 % in Kalina as compared to about 30 % in Ep 1 . Relative ¹⁴C uptake of branches was in a similar range, but great proportions of the ¹⁴C taken up by branches was translocated to main stems. No genotype x plant density interactions with respect to grain yield were recorded, indicating that yield formation at main stems and branches was affected by cropping conditions similarly in both genotypes. This applies to the conditions of the experiments, where stress effects were absent. Under these conditions, the conventional genotype showed agronomic, but no physiological disadvantages.     

Bark beetle community structure under four ponderosa pine forest stand conditions in northern Arizona

We studied the bark beetle guild (Coleoptera: Scolytidae) in the ponderosa pine forests of northern Arizona to explore if the species assemblages and relative abundance differ between managed and unmanaged stands. Four stand conditions were assessed: (1) unmanaged stands with high tree density, (2) thinned stands, (3) thinned and burned (with prescribed fire) stands and (4) stands that had been burned by stand replacing wildfires. The study was conducted in the ponderosa pine forests of the Coconino Plateau, northern Arizona. For several decades this area has been relatively free of bark beetle outbreaks despite the current overstocked condition of many stands. We found that a similar species assemblage composed of Dendroctonus frontalis, D. brevicomis, D. valens, D. approximatus, D. ponderosae, and Ips pini occurred across all four stand conditions over 3 years of study. The population levels of all these species were endemic across all stand conditions. The non-aggressive D. approximatus and D. valens were indicator species for thinned and unmanaged stands, respectively, but this was not consistent among years. The ambrosia beetle Gnathotrichus sp. and the bark beetle predator Enoclerus sp. consistently indicated stands burned by wildfire. In addition to our field experiment, we analyzed the historical pattern of attacks of bark beetles in our area of study. Our findings suggest that the pattern of attack of D. brevicomis (the only Dendroctonus species for which attacks have been reported) and Ips spp. has been through scattered small infestations in groups of 1–10 trees. Whereas small infestations by Ips spp. are increasing, those for D. brevicomis are decreasing. Although we agree that the high density stands in northern Arizona are in an “unhealthy” condition, our results do not show that they were supporting large bark beetle outbreaks. Our results challenge the theoretical assumptions about the relationship between stand structure, tree resistance and bark beetle performance.