The effects of exogenous xylanase supplementation on the in vivo generation of xylooligosaccharides and monosaccharides in broilers fed a wheat-based diet.

1. This study quantified xylanase-induced changes in soluble monosaccharides, xylooligosaccharides (XOS) and volatile fatty acid (VFA) contents of the different sections of the gastrointestinal tract (GIT) and whether these were related to altered bird performance. 2. An in vitro digestion of the wheat-based diet was carried out with the xylanase (Econase XT at 16,000BXU/kg diet) to compare the in vitro and in vivo generation of these XOS and monosaccharides. For the in vivo study, 80 male Ross 508 b roiler chicks were split into two groups fed a wheat-based diet with or without Econase XT (16,000BXU/kg diet) for 21 days. 3. There were no effects of Econase XT inclusion on growth performance characteristics, likely a result of the high-quality wheat diet, the corresponding high performance of the control group (FCR average of 1.45 in controls) and the relatively young age of the birds (from four to 26 days of age). 4. Econase XT supplementation increased the xylotetraose (X4) content in the colon (P = 0.046, enzyme x GIT section interaction) and the xylose contents in the colon and caeca (P < 0.001, enzyme x GIT section interaction). 5. The trend for increased acetate production in the caeca of Econase XT treated birds (P = 0.062) suggested that the XOS generated were subsequently fermented in the caeca, potentially impacting upon the types of microbiota present. 6. The present study suggested that wheat arabinoxylan degradation was enhanced by xylanase supplementation, which may have increased the production of beneficial volatile fatty acids (VFA) in the caeca, and thereby potentially modulated the caecal microbiome, but without affecting bird performance at this early age.

Acute lion's mane jellyfish, Cyanea capillata (Cnideria: Scyphozoa), exposure to Atlantic salmon (Salmo salar L.).

Jellyfish-induced gill pathology relies upon occasional diagnostic observations yet the extent and impact of jellyfish blooms on aquaculture may be significant. Idiopathic gill lesions are often observed in apparently healthy fish. This study exposed Atlantic salmon (Salmo salar L.) smolts to macerated Cyanea capillata at 2.5 and 5 g/L for 2 hr under controlled laboratory conditions. Blood chemistry and gill histopathology were examined over a subsequent 4-week period. Fish showed an acute response to the presence of jellyfish, including characteristic external "whiplash" discoloration of the skin and acute increases in blood electrolytes and CO2 concentration; however, these were resolved within 4 days after exposure. Histopathologically, gills showed first an acute oedema with epithelial separation followed by focal haemorrhage and thrombus formation, and then progressive inflammatory epithelial hyperplasia that progressively resolved over the 4 weeks post-exposure. Results were consistent with the envenomation of gills with cytotoxic neurotoxins and haemolysins known to be produced by C. capillata. This study suggests that many focal hyperplastic lesions on gills, especially those involving focal thrombi, may be the result of jellyfish stings. Thus, the presence of jellyfish and their impact may be severe and understated in terms of marine fish aquaculture and fish welfare.

Overexpression of AtCSP4 affects late stages of embryo development in Arabidopsis.

Eukaryotic cold shock domain proteins are nucleic acid-binding proteins that are involved in transcription, translation via RNA chaperone activity, RNA editing, and DNA repair during tissue developmental processes and stress responses. Cold shock domain proteins have been functionally implicated in important developmental transitions, including embryogenesis, in both animals and plants. Arabidopsis thaliana cold shock domain protein 4 (AtCSP4) contains a well conserved cold shock domain (CSD) and glycine-rich motifs interspersed by two retroviral-like CCHC zinc fingers. AtCSP4 is expressed in all tissues but accumulates in reproductive tissues and those undergoing cell divisions. Overexpression of AtCSP4 reduces silique length and induces embryo lethality. Interestingly, a T-DNA insertion atcsp4 mutant does not exhibit any morphological abnormalities, suggesting that the related AtCSP2 gene is functionally redundant with AtCSP4. During silique development, AtCSP4 overexpression induced early browning and shrunken seed formation beginning with the late heart embryo stage. A 50% segregation ratio of the defective seed phenotype was consistent with the phenotype of endosperm development gene mutants. Transcripts of FUS3 and LEC1 genes, which regulate early embryo formation, were not altered in the AtCSP4 overexpression lines. On the other hand, MEA and FIS2 transcripts, which are involved in endosperm development, were affected by AtCSP4 overexpression. Additionally, AtCSP4 overexpression resulted in up-regulation of several MADS-box genes (AP1, CAL, AG, and SHP2) during early stages of silique development. Collectively, these data suggest that AtCSP4 plays an important role during the late stages of silique development by affecting the expression of several development-related genes.

Phosphorus in surface runoff from calcareous arable soils of the semiarid Western United States.

Management strategies that minimize P transfer from agricultural land to water bodies are based on relationships between P concentrations in soil and runoff. This study evaluated such relationships for surface runoff generated by simulated sprinkler irrigation onto calcareous arable soils of the semiarid western United States. Irrigation was applied at 70 mm h(-1) to plots on four soils containing a wide range of extractable P concentrations. Two irrigation events were conducted on each plot, first onto dry soil and then after 24 h onto wet soil. Particulate P (>0.45 microm) was the dominant fraction in surface runoff from all soils and was strongly correlated with suspended sediment concentration. For individual soil types, filterable reactive P (<0.45 microm) concentrations were strongly correlated with all soil-test P methods, including environmental tests involving extraction with water (1:10 and 1:200 soil to solution ratio), 0.01 M CaCl(2), and iron strips. However, only the Olsen-P agronomic soil-test procedure gave models that were not significantly different among soils. Soil chemical differences, including lower CaCO(3) and water-extractable Ca, higher water-extractable Fe, and higher pH, appeared to account for differences in filterable reactive P concentrations in runoff from soils with similar extractable P concentrations. It may therefore be possible to use a single agronomic test to predict filterable reactive P concentrations in surface runoff from calcareous soils, but inherent dangers exist in assuming a consistent response, even for one soil within a single field.

Colloidal phosphorus in surface runoff and water extracts from semiarid soils of the western United States.

Colloidal particles in runoff may have an important role in P transfer from soils to waterbodies, but remain poorly understood. We investigated colloidal molybdate-reactive phosphorus (MRP) in surface runoff and water extracts of calcareous arable soils from the semiarid western United States. Colloidal MRP was determined by ultrafiltration and operationally defined as MRP associated with particles between 1 microm and 1 nm diameter, although a smaller pore-size filter (0.3 nm) was used to define the lower size limit of colloids in water extracts. In surface runoff from three calcareous soils generated by simulated sprinkler irrigation, colloidal MRP concentrations ranged between 0.16 and 3.07 microM, constituting between 11 and 56% of the MRP in the <1-microm fraction. Concentrations were strongly correlated with agronomic and environmental soil-test P concentrations for individual soils. Water extracts of a range of similar soils contained two size fractions of colloidal MRP: a larger fraction (1.0-0.2 microm) probably associated with fine clays, and a smaller fraction (3-0.3 nm) probably associated with Ca-phosphate minerals. Colloidal MRP was solubilized in the acidic medium of the colorimetric detection procedure, suggesting that a fraction of the filterable MRP in runoff from calcareous soils may not be as readily bioavailable as free phosphate in waterbodies. Our results suggest that colloidal MRP is an important but poorly understood component of P transfer in runoff from calcareous western U.S. soils and should be given greater consideration in mechanistic studies of the P transfer process.

Clinical efficacy of microencapsulated timothy grass pollen extract in grass-allergic individuals.

BACKGROUND: Conventional allergen immunotherapy is clinically effective in reducing the symptoms of allergic rhinitis and asthma. It differs from other pharmacotherapies in that it can induce long-term clinical remission of these diseases. However, it requires years of treatment and is associated with serious allergic reactions. OBJECTIVE: To evaluate the safety, clinical efficacy, and immunologic mechanisms of immunotherapy with an oral, microencapsulated form of timothy grass allergen. METHODS: In this double-blind, placebo-controlled study, 24 patients aged 19 to 55 years with grass pollen allergy were randomized to receive either microencapsulated timothy grass pollen extract or placebo once a day for 10 weeks. The dose of study drug was doubled weekly. Safety was evaluated through weekly visits, daily symptom diaries, and routine laboratory tests. Efficacy was evaluated by comparing medication use and symptoms scores during peak grass pollen season before and after treatment. Allergen-specific T-cell responses, cytokine production, and IgG, IgE, and skin reactivity were measured to evaluate immunologic mechanisms. RESULTS: Eleven of 12 patients in the active treatment group had a decrease in the combined medication and symptom score, but only 4 of 10 patients in the placebo group had a decrease in scores. The proliferative response to timothy grass was reduced by at least 30% in 9 of the 12 grass-treated patients, but only 3 of 11 placebo patients had a proliferative response reduction. Timothy grass-induced interleukin-5 messenger RNA was reduced in the active group, but not in the placebo group. There were no significant changes in either group in IgG, IgE, and skin reactivity. CONCLUSIONS: Oral immunotherapy with microencapsulated allergen induces a form of immunologic tolerance to the allergen and is a safe, efficient, and effective method of allergen immunotherapy.