Zur Stickstoffdynamik unter Exkrementflecken bei Weidegang     

Günter Spatz  Jochen Neuendorff  Arnold Pape  Claudia Schrder 《植物养料与土壤学杂志》1992,155(4):301-305

Nitrogen Dynamics Under Excrement Patches in Pastures Soil mineral nitrogen contents in relation to time were measured under excrement patches on three pastures in Lower Saxony. The highest values were found under patches of urine on a pasture grazed by suckling cows. The herbage dry matter of that pasture showed a crude protein content of 19 %. The contents of mineral nitrogen under urine patches were less on a comparable pasture utilized by milking cows. The concentrations were still less on a cow grazed pasture, which remained unfertilized over a period of ten years. The content of NH₄-N under urine affected areas increased distinctly in the whole soil profile, within one day of deposition. High NO₃-N concentrations were found even in deeper soil layers after one week. The nitrogen concentrations under patches of urine approximated the values under not urine affected parts of the pasture within three months. The increments of mineral nitrogen under patches of faeces were insignificant.  相似文献   

On the potential of documenting decadal-scale avifaunal change from before-and-after comparisons of museum and observational data across North America     

Fernando Machado-Stredel  Benedictus Freeman  Daniel Jiménez-Garcia  Marlon E.Cobos  Claudia Nu?ez-Penichet  Laura Jiménez  Ed Komp  Utku Perktas  Ali Khalighifar  Kate Ingenloff  Walter Tapondjou  Thilina de Silva  Sumudu Fernando  Luis Osorio-Olvera  A.Townsend Peterson 《中国鸟类》2022,(1):1-10

Studies of biodiversity dynamics have been cast on either long(systematics)or short(ecology)time scales,leaving a gap in coverage for moderate time scales of de...  相似文献   

Aspects of prenatal development of muscle and adipose tissue: principles, regulation, and influence of maternal nutrition     

Kalbe C  Rehfeldt C 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(11-12):509-520

During pregnancy the developing embryo/foetus is completely dependent on the supply with nutrients and the removal of metabolic by-products through the maternal organism. Therefore, each lasting inadequate nutrient supply may have serious consequences for foetal development. As a kind of "nutritional programming" resulting adaptive changes may be maintained until or manifested at adult age. Intrauterine growth retardation (IUGR) may cause problems in animal health and result in poor animal performance. The relationships between prenatal development and the postnatal phenotypic appearance of muscle and fat are insufficiently investigated. The present paper provides selected aspects of the prenatal development of skeletal muscle (myogenesis) and adipose tissue (adipogenesis), refers to the importance of interactions between both tissues and is focussed on the influence of maternal nutrition on these processes.  相似文献   

Immunoglobulin E-bearing cells and mast cells in skin biopsies of horses with urticaria     

Rüfenacht S  Marti E  von Tscharner C  Doherr MG  Forster U  Welle M  Roosje PJ 《Veterinary dermatology》2005,16(2):94-101

The pathogenesis of equine urticaria is not well understood. In man, urticaria has been associated with immunological and nonimmunological mechanisms leading to the release of various mediators by mast cells. Skin biopsies of 32 horses with a history of urticaria were stained with toluidine blue, a double-labelling method for chymase and tryptase, and immunohistochemistry for immunoglobulin (Ig)E. These horses were compared with horses with pemphigus foliaceus, insect bite hypersensitivity and control horses with healthy skin. Neither formalin fixation time nor biopsy site influenced the staining methods. No chymase-positive cells were found. In all groups of horses, cells staining with toluidine blue and for tryptase and IgE were found in the epidermis and hair follicle papilla and significantly more positively staining cells were observed in the subepidermal dermis compared with the deep dermis. Horses with urticaria had significantly more IgE-bearing cells in the subepidermal dermis than control horses. However, horses with urticaria had significantly fewer toluidine-blue-stained mast cells in both subepidermal and deep dermis compared with the insect bite hypersensitivity and pemphigus foliaceus groups. This study suggests that IgE-mediated reactions play a role in the pathogenesis of urticaria.  相似文献   

Evaluation of the association between initial proteinuria and morbidity rate or death in dogs with naturally occurring chronic renal failure     

Jacob F  Polzin DJ  Osborne CA  Neaton JD  Kirk CA  Allen TA  Swanson LL 《Journal of the American Veterinary Medical Association》2005,226(3):393-400

OBJECTIVE: To determine whether urine protein-to-creatinine ratio (UP:C) > or = 1.0 at initial diagnosis of chronic renal failure (CRF) is associated with greater risk of development of uremic crises, death, and progression of renal failure in dogs. DESIGN: Prospective cohort study. ANIMALS: 45 dogs with CRF PROCEDURE: Dogs were prospectively assigned to 2 groups on the basis of initial UP:C < 1.0 or 2 > or = 1.0. The association between magnitude of proteinuria and development of uremic crises and death was determined before and after dogs with initial UP:C > or =1.0 were assigned to 3 subgroups and compared with dogs with initial UP:C < 1.0. Changes in reciprocal serum creatinine concentration were used to estimate decrease in renal function. RESULTS: Initially, dogs had similar clinical characteristics with the exception of systolic blood pressure and UP:C. Relative risks of development of uremic crises and death were approximately 3 times higher in dogs with UP:C > or =1.0, compared with dogs with UP:C < 1.0. Relative risk of adverse outcome was approximately 1.5 times higher for every 1-unit increment in UP:C. The decrease in renal function was of greater magnitude in dogs with UP:C > or =1.0, compared with dogs with UP:C < 1.0. CONCLUSIONS AND CLINICAL RELEVANCE: Initial UP:C > or =1.0 in dogs with CRF was associated with greater risk of development of uremic crises and death, compared with dogs with UP:C < 1.0. Initial determinations of UP:C in dogs with naturally occurring CRF may be of value in refining prognoses.  相似文献   

Influence of murine Toxocara canis infection on plasma and bronchoalveolar lavage fluid eosinophil numbers and its correlation with cytokine levels     

Pecinali NR  Gomes RN  Amendoeira FC  Bastos AC  Martins MJ  Pegado CS  Bastos OM  Bozza PT  Castro-Faria-Neto HC 《Veterinary parasitology》2005,134(1-2):121-130

Toxocara canis is a nematode of the Ascaridae family that normally parasites the small intestine of canid species. Humans are accidentally infected upon ingestion of embryonated eggs, and can manifest several clinical alterations such as fever, hepatomegaly, splenomegaly, respiratory symptoms, muscle pain and anorexia. In the present work, we investigated the kinetics of tissue distribution of L2 larva in lungs, liver, kidney, brain, skeletal muscle and myocardium. Also, we analyzed the blood and bronchoalveolar lavage fluid (BAL) for levels of IL-6, IFN-gamma, eotaxin and Regulated on Activation Normal T Cell Expressed and Secreted (RANTES) in experimental murine T. canis infection. We observed liver, lung and kidney lesions correlated to larva migration as early as the first day of infection. After the seventh post-infection day, larva could also be detected in brain, skeletal muscle and heart, as an indicator of biphasic migration pattern. Increased inflammatory activity was detected in BAL and plasma of infected animals, as was an intense eosinophil migration associated with an increase in the levels of all the cytokines studied. In conclusion, our results establish a tight correlation between tissue lesions caused by larva migration and increased plasma levels of pro-inflammatory and eosinophil chemotactic cytokines. Thus, murine T. canis infection may prove to be useful in understanding the role of cytokines in infection.  相似文献   

Inhibitory and excitatory neurotransmitters in the cerebrospinal fluid of epileptic dogs   总被引：3，自引：0，他引：3  

Ellenberger C  Mevissen M  Doherr M  Scholtysik G  Jaggy A 《American journal of veterinary research》2004,65(8):1108-1113

OBJECTIVE: To determine concentrations of excitatory and inhibitory amino acids in CSF of a large number of dogs with idiopathic epilepsy or genetic epilepsy and to evaluate changes in CSF amino acid concentration with regard to drug treatment and sex. ANIMALS: 35 Labrador Retrievers with genetic epilepsy (20 male and 15 female), 94 non-Labrador Retrievers with idiopathic epilepsy (71 male and 23 female), and 20 control dogs (10 male and 10 female). PROCEDURE: Collection of CSF was performed > 72 hours after the occurrence of seizures. Cerebrospinal fluid concentrations of gamma-aminobutyric acid (GABA), glutamate (GLU), aspartate (ASP), serine, and glycine were determined by use of high performance liquid chromatography with electrochemical detection. RESULTS: CSF concentrations of GABA and GLU were significantly lower in Labrador Retrievers with genetic epilepsy (LR-group dogs) than in control-group dogs or in non-Labrador Retrievers with idiopathic epilepsy (non-LR-group dogs). The GLU-to-GABA ratio was significantly higher in LR-group dogs than in non-LR-group dogs. CSF concentrations of GLU and ASP were significantly lower when all dogs with epilepsy (non-LR- and LR-group dogs combined) were compared with control-group dogs. CONCLUSIONS AND CLINICAL RELEVANCE: A decrease in CSF concentrations of GABA appears to play a role in the pathogenesis of genetically determined epilepsy in Labrador Retrievers. However, this decrease in CSF concentrations of GABA may also be a consequence of seizure activity. The GLU-to-GABA ratio may prove to be a useful indicator of genetic epilepsy in Labrador Retrievers.  相似文献   

Flavanol and bound phenolic acid contents in different barley varieties     

Holtekjølen AK  Kinitz C  Knutsen SH 《Journal of agricultural and food chemistry》2006,54(6):2253-2260

Different barley varieties, consisting of hulled and hull-less types, of normal, waxy, and high amylose starch, as well as two-rowed and six-rowed types, were analyzed for their main proanthocyanidins and bound phenolic acids. Variations in proanthocyanidin and phenolic acid contents were studied in different barley types as well as inter-relationships between the phytochemicals and polysaccharides. The main flavanols found in the analyzed barley varieties were two dimeric as well as four trimeric forms in addition to catechin. The total amount of flavanols ranged from 325 to 527 microg/g of fresh weight of barley flour. No evident associations were found between variations in proanthocyanidin levels and different barley types. The total amount of phenolic acids ranged from 604 to 1346 microg/g of fresh weight of barley flour, with ferulic acid as the dominating acid. The amount of phenolic acids varied according to occurrence or lack of hull, with significantly higher levels in the hulled varieties.  相似文献   

Tissue tropism of Helicobacter pullorum in specific pathogen-free chickens determined by culture and nucleic acid detection     

Neubauer C  Hess M 《Avian diseases》2006,50(4):620-623

Three-day-old specific pathogen-free chickens (n = 24) located in isolators were inoculated orally with Helicobacter pullorum. One group (n = 12) was infected with a H. pullorum field isolate from human origin, another one (n = 12) with the American Type Culture Collection H. pullorum reference isolate 51801 originating from chickens. Both isolates were positive for cytolethal distending toxin, investigated using a polymerase chain reaction (PCR). A third group (n = 4) was kept as a negative control. Starting on day 7 of life, birds from each group were euthanatized at different time points up to 35 days. Various organ samples were taken aseptically and processed by culture and a H. pullorum-specific PCR. In the group infected with the human isolate the nucleic acid of H. pullorum was detected in the caecal tonsils and caeca of 12 and 11 birds, respectively. Live bacteria were cultivated from the caecal tonsils and caeca of five birds 24 and 31 days postinfection. Live bacteria were also isolated from the heart of one bird, whereas PCR had to be used to detect the nucleic acid of H. pullorum in the gallbladder of four birds. No live bacteria were reisolated at any time from birds infected with the avian isolate, but bacterial nucleic acid was detected in the caeca of five birds and in the gallbladder of one. In both groups neither live H. pullorum nor its nucleic acid were detected in the liver, spleen, and duodenum. Compared to the avian H. pullorum isolate the human isolate proved to be more invasive. No obvious clinical symptoms or disease was seen in the chickens during the entire experiment. The reisolation of live bacteria at the end of the experiments indicates that H. pullorum could enter the food chain even after early infection in birds. Furthermore, PCR was demonstrated to be helpful in tracing these fastidious bacteria.  相似文献   

Quantification of jasmonic acid by SPME in tomato plants stressed by ozone     

Zadra C  Borgogni A  Marucchini C 《Journal of agricultural and food chemistry》2006,54(25):9317-9321

Jasmonates are signalling molecules induced in plants as a response to various biotic and/or abiotic stresses. As ozone is known to activate defense responses in plants, we have monitored the concentration of jasmonic acid in tomato leaves during and after an acute exposure to this abiotic elicitor. In this experiment, we observed that the maximum induction of jasmonic acid in O3-fumigated plants occurred 9 h after the end of treatment and the concentration of jasmonic acid in stressed plants increased 13-fold. However, the level of endogenous methyl-jasmonate was constant during the observed period. The extraction and quantification of jasmonic acid as its methyl ester was performed by headspace-solid-phase microextraction (or HS-SPME) in combination with GC-FID and GC-MS. The sensitivity (LOD = 2 ng/g) of this method permitted the detection and quantification of jasmonic acid present in plant tissues at very low concentrations.  相似文献