Dietary tryptophan supplementation does not affect growth but increases brain serotonin level and modulates the expression of some liver genes in zebrafish (Danio rerio)     

Teixeira  Cláudia  Rodrigues  Pedro  Serrão  Paula  Figueira  Luís  Guimarães  Laura  Teles  Luís Oliva  Peres  Helena  Carvalho  António Paulo 《Fish physiology and biochemistry》2021,47(5):1541-1558

This study aimed at assessing the effects of the dietary tryptophan (Trp) supplementation on growth and feed utilization, brain serotonin content, and expression of selected liver genes (involved in the liver serotonin pathway, protein synthesis degradation, and antioxidant activity) in zebrafish. A growth trial was conducted with zebrafish juveniles fed five experimental isoproteic (40%DM) and isolipidic (8%DM) fishmeal-based diets containing graded levels of Trp: a Trp-non-supplemented diet (diet Trp0, with 0.22% Trp) and four Trp-supplemented diets containing 2–16 times higher Trp content (diets Trp2, Trp4, Trp8, and Trp16 with 0.40, 0.91, 2.02, and 3.34% Trp, respectively). Diets were tested in quadruplicate, with fish being fed twice a day, 6 days a week for 6 weeks to apparent visual satiation. At the end of the trial, growth performance and feed utilization were assessed, and fish from all experimental groups were sampled for whole-body composition analysis. In addition, fish fed low (Trp0), medium (Trp4), and high (Trp16) Trp diets were also sampled for analysis of brain serotonin content and liver gene expression. Tested tryptophan levels did not influence growth performance nor feed intake. However, values of energy and nitrogen retention as well as body energy content indicate a better feed utilization with diets containing around 0.9% and 2.0% DM Trp. Brain serotonin content increased with increasing dietary tryptophan levels. In addition, regarding liver genes, dietary treatment had a modulatory effect on the expression of Htr1aa and Htr2cl1 genes (encoding for serotonin receptors), TPH1a gene (encoding for tryptophan hydroxylase, the rate-limiting enzyme in the synthesis of serotonin from tryptophan), TOR gene (involved in protein synthesis), and Keap1 gene (involved in antioxidant responses).

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Modulating the persistence and bioactivity of allelochemicals in the rhizosphere: salicylic acid,a case of study     

Beatriz Gámiz  Gracia Facenda  Rafael Celis 《Archives of Agronomy and Soil Science》2019,65(5):581-595

The activity of allelochemicals in agroecosystems is highly dependent on their soil persistence. The aim of this work was to establish a link between the soil persistence of salicylic acid (SA) and its bioactivity, to better understand the mechanisms of allelochemical-mediated soil-plant interactions. Incubation and bioassay experiments were conducted for this purpose. The addition of HgCl₂ and decreasing temperature to 4 °C increased the persistence of SA in soil. Since these treatments greatly decreased the soil respiration, they probably slowed the SA dissipation by reducing the soil microbial activity. To a lesser extent, soil humidity and soil pH also influenced the SA dissipation rate. Exogenous olive-mill organic waste (ALP) increased the soil respiration, but interestingly, delayed the degradation of SA, presumably because ALP acted as an alternative source of C for soil microorganisms. The phytotoxicity of SA towards Eruca vesicaria in soil increased by the addition of ALP. Applied to soil at 0.5%, ALP reduced the SA dose for 50% Eruca vesicaria aerial biomass inhibition to 40%. Our results show how certain agronomic practices, such as the application of agri-industrial biosolids, could be used to modulate the persistence of allelochemicals in the rhizosphere and control their biological functions in soils.  相似文献   

Interspecific competition changes nutrient : nutrient ratios of weeds and maize     

Christiano da Conceio de Matos  Rafael da Silva Teixeira  Ivo Ribeiro da Silva  Maurício Dutra Costa  Antonio Alberto da Silva 《植物养料与土壤学杂志》2019,182(2):286-295

The elemental ratios of plant tissues are associated with the adaptive and competitive success of a plant species in an ecosystem. So far, no study has evaluated if and how crop–weed competition influences the elemental ratios of competing populations, although such information is important to understand weed infestation dynamics and to improve weed management in agroecosystems. The objective of this study was to analyze weed–crop elemental ratios during interspecific competition between weeds and crops in greenhouse experiments. For this, maize (Zea mays L.) and the weeds Amaranthus viridis L, Bidens pilosa L., and Ipomoea grandifolia (Dammer) O'Donell were grown under seven treatments: maize and weed monocultures, and maize in competition with weeds. Competition between plants practically did not influence growth and nutrient contents of maize but reduced weed growth and nutrient uptake. Maize showed few changes in elemental ratios. In contrast, B. pilosa and I. grandifolia were very sensitive to competition and showed significant increases in C : N, C : P, C : K, N : P, and N : K ratios when grown with maize. A. viridis showed low flexibility of nutrient : nutrient ratios under the same competitive pressure as that faced by B. pilosa and I. grandifolia. The interspecific competition led to increases only in the C : P ratio of A. viridis shoots. Therefore, interspecific competition changes the elemental ratios, mainly of the weeds, and the magnitude of this change is dependent on the plant species involved. Interspecific competition changes plant biomass quality (higher C : nutrient ratios), mainly for B. pilosa and I. grandifolia.  相似文献   

Assessment of apoptosis in epidermal lamellar cells in clinically normal horses and those with laminitis     

Faleiros RR  Stokes AM  Eades SC  Kim DY  Paulsen DB  Moore RM 《American journal of veterinary research》2004,65(5):578-585

OBJECTIVE: To determine and compare the number, type, location, and distribution of apoptotic epidermal cells in the laminae of clinically normal horses and horses with laminitis. SAMPLE POPULATION: Formalin-fixed samples of digital lamellar tissue from 47 horses (including clinically normal horses [controls; n = 7], horses with acute [4] and chronic [7] naturally acquired laminitis, and horses with black walnut extract-induced [11] or carbohydrate overload-induced [18] laminitis). PROCEDURE: Blocks of paraffin-embedded lamellar tissues were stained for DNA fragmentation with the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. Differential immunohistochemical staining for caspases 3 and 14 were used to confirm apoptosis. RESULTS: The number of TUNEL-positive epidermal cells per 0.1 mm of primary laminae was significantly greater in the acute laminitis group than in the other groups. In the acute laminitis group, there were 17 and 1,025 times as many TUNEL-positive basal layer cells and keratinocytes, respectively, compared with the control group. Apoptosis of TUNEL-positive basal layer cells was confirmed by results of caspase 3 immunohistochemical staining. The TUNEL-positive keratinocytes did not stain for caspases 3 or 14. CONCLUSIONS AND CLINICAL RELEVANCE: The large number of apoptotic basal layer cells detected in the lamellar tissue of horses with acute naturally acquired laminitis suggests that apoptosis may be important in the development of acute laminitis. The role of the large number of TUNEL-positive keratinocytes detected in the interface of primary and secondary epidermal laminae of horses with acute laminitis remains to be elucidated.  相似文献   

Determination of specific receptor sites for platelet activating factor in bovine neutrophils   总被引：1，自引：0，他引：1  

Burgos RA  Hidalgo MA  Matthei SM  Hermosilla R  Folch H  Hancke JL 《American journal of veterinary research》2004,65(5):628-636

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Effects of four anaesthetic protocols on the neurological and cardiorespiratory variables of puppies born by caesarean section     

Luna SP  Cassu RN  Castro GB  Teixeira Neto FJ  Silva Júnior JR  Lopes MD 《The Veterinary record》2004,154(13):387-389

Twenty-four bitches which had been in labour for less than 12 hours were randomly divided into four groups of six. They all received 0.5 mg/kg of chlorpromazine intravenously as premedication, followed 15 minutes later by either 8 mg/kg of thiopentone intravenously (group 1), 2 mg/kg of ketamine and 0.5 mg/kg of midazolam intravenously (group 2), 5 mg/kg of propofol intravenously (group 3), or 2.5 mg/kg of 2 per cent lidocaine with adrenaline and 0.625 mg/kg of 0.5 per cent bupivacaine with adrenaline epidurally (group 4). Except for group 4, the bitches were intubated and anaesthesia was maintained with enflurane. The puppies' heart and respiratory rates and their pain, sucking, anogenital, magnum and flexion reflexes were measured as they were removed from the uterus. The puppies' respiratory rate was higher after epidural anaesthesia. In general the puppies' neurological reflexes were most depressed after midazolam/ketamine, followed by thiopentone, propofol and epidural anaesthesia.  相似文献   

Parasitic helminths in the digestive tract of six species of owls (Strigiformes) in Spain     

Ferrer D  Molina R  Castellà J  Kinsella JM 《Veterinary journal (London, England : 1997)》2004,167(2):181-185

A survey was carried out in Catalonia, Spain to determine the prevalence of parasitic helminths infesting the digestive tract of nocturnal raptors (Strigiformes). One hundred birds belonging to six owl species were examined. The number of birds examined ranged between three and 30. The overall level of infestation was 65% and the most frequent helminths present were nematodes, followed by trematodes, cestodes and acanthocephalans. Strigiformes showing the highest levels of infestation were little owls (Athene noctua), 86.7% of which were infested. Helminths with the highest prevalence were Synhimantus spp., intestinal capillarids, Brachylaima spp., cestodes and Centrorhynchus aluconis.  相似文献   

Transvenous electrical cardioversion in equine atrial fibrillation: technique and successful treatment of 3 horses     

McGurrin MK  Physick-Sheard PW  Kenney DG  Kerr C  Hanna WJ  Neto FT  Weese JS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(5):715-718

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Osmotin and thaumatin from grape: a putative general defense mechanism against pathogenic fungi   总被引：1，自引：0，他引：1  

Monteiro S  Barakat M  Piçarra-Pereira MA  Teixeira AR  Ferreira RB 《Phytopathology》2003,93(12):1505-1512

ABSTRACT Little information is available concerning the expression of pathogenesis-related (PR) proteins in grapevine (Vitis vinifera) and their effect properties on the major fungal pathogens of grape. A systematic study was performed on the effect of total or individual grape proteins on mycelial growth, spore germination, and germ tube growth of Uncinula necator, Phomopsis viticola, and Botrytis cinerea. Two proteins, identified as PR proteins by immunological methods and by N-terminal sequencing as osmotin and thaumatin-like protein, exhibited strong antifungal activities in vitro, blocking the growth of Phomopsis viticola and Botrytis cinerea mycelia. In addition, they inhibited spore germination and germ tube growth of U. necator, Phomopsis viticola, and Botrytis cinerea. The presence of both proteins displayed a synergistic effect. The expression of osmotin and thaumatin-like protein was induced in grapevine leaves and berries infected with U. necator and Phomopsis viticola. Thaumatin previously was thought to occur exclusively in berries. Immunoblot analyses revealed the accumulation of the two PR proteins in infected leaves and berries, supporting a role in vivo in increasing the resistance of grapevine to fungal attack.  相似文献   

Development of a Specific Polymerase Chain Reaction-Based Assay for the Identification of Fusarium oxysporum f. sp. ciceris and Its Pathogenic Races 0, 1A, 5, and 6     

Del Mar Jiménez-Gasco M  Jiménez-Díaz RM 《Phytopathology》2003,93(2):200-209

ABSTRACT Specific primers and polymerase chain reaction (PCR) assays that identify Fusarium oxysporum f. sp. ciceris and each of the F. oxysporum f. sp. ciceris pathogenic races 0, 1A, 5, and 6 were developed. F. oxysporum f. sp. ciceris- and race-specific random amplified polymorphic DNA (RAPD) markers identified in a previous study were cloned and sequenced, and sequence characterized amplified region (SCAR) primers for specific PCR were developed. Each cloned RAPD marker was characterized by Southern hybridization analysis of Eco RI-digested genomic DNA of a subset of F. oxysporum f. sp. ciceris and nonpathogenic F. oxysporum isolates. All except two cloned RAPD markers consisted of DNA sequences that were found highly repetitive in the genome of all F. oxysporum f. sp. ciceris races. F. oxysporum f. sp. ciceris isolates representing eight reported races from a wide geographic range, nonpathogenic F. oxysporum isolates, isolates of F. oxysporum f. spp. lycopersici, melonis, niveum, phaseoli, and pisi, and isolates of 47 different Fusarium spp. were tested using the SCAR markers developed. The specific primer pairs amplified a single 1,503-bp product from all F. oxysporum f. sp. ciceris isolates; and single 900- and 1,000-bp products were selectively amplified from race 0 and race 6 isolates, respectively. The specificity of these amplifications was confirmed by hybridization analysis of the PCR products. A race 5-specific identification assay was developed using a touchdown-PCR procedure. A joint use of race 0- and race 6-specific SCAR primers in a single-PCR reaction together with a PCR assay using the race 6-specific primer pair correctly identified race 1A isolates for which no RAPD marker had been found previously. All the PCR assays described herein detected up to 0.1 ng of fungal genomic DNA. The specific SCAR primers and PCR assays developed in this study clearly identify and differentiate isolates of F. oxysporum f. sp. ciceris and of each of its pathogenic races 0, 1A, 5, and 6.  相似文献