Ligno-aliphatic complexes in soils revealed by an isolation procedure: implication for lignin fate     

Mathieu Thevenot  Marie-France Dignac  Mercedes Mendez-Millan  Haithem Bahri  Christine Hatté  Gérard Bardoux  Cornelia Rumpel 《Biology and Fertility of Soils》2013,49(5):517-526

For the last decades, the fate of lignins in soil was analyzed mainly with cupric oxide (CuO) oxidation, which is traditionally used to quantify soil lignin content and characterize its state of degradation. This method presents limitations due to incomplete depolymerization of the lignin structure. In this study, we used a physicochemical soil lignin isolation procedure, which permits recovery of a milled wall enzymatic lignin (MWEL) fraction. Elemental composition and chemical structure of MWEL isolated from plants and soil were characterized. Its incorporation rate into an agricultural loamy soil was studied using stable isotope analyses of MWEL isolated from soils after 0 to 9 years of maize cultivation after wheat. Comparison of MWEL isolated from maize tissues and soil provided information on evolution of the lignin structure once incorporated into soil. We observed aromatic–aliphatic complex formation, which could lead to its sequestration in soil evidenced by increasing MWEL content after 9 years of maize cultivation. The ¹³C natural abundance of isolated MWEL showed faster incorporation of MWEL (17.4 % of renewed lignins after 9 years) compared to total soil organic matter (9 % of total soil organic carbon (SOC) was renewed). This faster incorporation rate of MWEL compared to bulk soil organic matter is in agreement with lignin turnover observed by CuO oxidation. Radiocarbon dating of MWEL suggested a mean age of around 50 years. We conclude that lignin isolation allows (1) access to a different fraction compared to CuO oxidation and (2) a detailed characterization of lignin transformation in soil. We suggest that interaction with aliphatic compounds could be one possible pathway of lignin preservation in soil.  相似文献   

The hardness of horn in different segments of the bovine claw     

Hinterhofer C  Zöscher M  Gabler C  Stanek C 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(7-8):334-340

Hardness of bovine hoof horn was tested as ball indentation hardness and as shore D hardness post mortem in different segments of the hoof wall, in the sole and the hard bulb of sound claws of 10 Austrian Holstein Friesian cows. Both methods of hardness determination showed corresponding results, with shore D hardness between 52.2 and 63.9 hardness units (hu) and ball indentation hardness between 11.2 N/mm2 and 24.3 N/mm2. Bovine hoof horn becomes significantly softer from the coronary band towards the weight bearing border (vertical decrease) and from the dorsal wall towards the heel (horizontal decrease). Decreasing hardness was associated with decreasing dry matter content. Measurements of the claw capsule showed thickness of the hoof wall increasing from the coronary border towards the sole. In dorsopalmar/-plantar direction, bovine hoof wall at the weight bearing border decreases towards the heel.  相似文献   

Pigmented-anaerobic bacteria associated with canine periodontitis     

Hardham J  Dreier K  Wong J  Sfintescu C  Evans RT 《Veterinary microbiology》2005,106(1-2):119-128

The etiology of human periodontal disease has been the focus of considerable research, yet relatively little is known about the causative agents of companion animal periodontitis. In humans, Porphyromonas gingivalis, a black-pigmented anaerobic bacteria (BPAB), has been implicated as the primary periopathogen. It has been demonstrated that BPAB are also found in companion animal periodontal pockets. While some animal BPAB have been individually identified, a study to identify the most frequently isolated subgingival BPAB has not been completed using genetic tools. The objective of this work was to identify the types and relative frequencies of pigmented anaerobic bacteria found in the periodontal pockets of dogs. Porphyromonas salivosa, Porphyromonas denticanis (a novel species) and Porphyromonas gulae were found to be the most frequently isolated BPAB associated with canine periodontitis.  相似文献   

From the editor     

Cornelia B. Flora  Richard P. Haynes 《Agriculture and Human Values》1985,2(1):1-4

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Prevalence of Escherichia coli O157:H7 prophage-like sequences among German Salmonella enterica serotype Typhimurium phage types and their use in detection of phage type DT104 by the polymerase chain reaction     

Malorny B  Schroeter A  Bunge C  Helmuth R 《Veterinary microbiology》2002,87(3):253-265

A 1.6kb DNA fragment identified by random amplifiable polymorphic DNA differentiation (RAPD) from a Salmonella enterica serotype Typhimurium phage type DT104 isolate was used to investigate the prevalence of the region in 160 DT104 isolates, 83 other epidemiological important S. Typhimurium phage types and 20 strains selected from 17 other Salmonella serotypes. PCR screening tests using two different primer-sets derived from the RAPD fragment's nucleotide sequence showed that 76% of the 160 DT104 isolates investigated, including subtypes DT104A, DT104B, DT104B low, DT104H and DT104L, reacted positively. High sensitivity was shown for DT104 strains expressing at least the penta-resistance pattern ACSSuT (97% of 104 strains tested). DT104 susceptible strains showed only a sensitivity of 35% (17 strains tested). In contrast, 83% of the 83 strains from the other S. Typhimurium phage types reacted negatively. Strains from five out of the 17 other serotypes showed a positive signal with one primer-set. The other primer-set exhibited only a positive reaction with one S. Dublin isolate. The analysis of a 2415bp extended sequence revealed homologies to genes encoded by Escherichia coli O157:H7 prophages, suggesting that the described region contains genes of a prophage specific for DT104 and related phage types.  相似文献   

Fasciolosis in camelids     

Harwood D  Nuttall J  Bidewell C 《The Veterinary record》2008,162(13):424

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Evaluation of cross-protection by immunization with an experimental trivalent companion animal periodontitis vaccine in the mouse periodontitis model     

Hardham J  Sfintescu C  Evans RT 《Journal of veterinary dentistry》2008,25(1):23-27

Companion animal periodontal disease is one of the most prevalent diseases seen by veterinarians. The goal of this study was to evaluate the vaccine performance of a trivalent canine periodontitis vaccine in the mouse oral challenge model of periodontitis. Mice vaccinated subcutaneously with an inactivated, whole-cell vaccine preparation of Porphyromonas denticanis, Porphyromonas gulae, and Porphyromonas salivosa displayed significantly reduced alveolar bone loss in response to heterologous and cross-species challenges as compared to sham vaccinated animals. Based on the results of these studies, a periodontitis vaccine may be a useful tool in preventing the initiation and progression of periodontitis caused by the most commonly isolated pigmenting anaerobic bacteria in animals.  相似文献   

Canine intervertebral disk disease: a retrospective study of clinical outcome in 238 dogs (2003-2004)     

Bull C  Fehr M  Tipold A 《Berliner und Münchener tier?rztliche Wochenschrift》2008,121(3-4):159-170

The aim of the study was the assessment of the prognosis of intervertebral disk diseases on the basis of a large case load with the help of currently available therapy modalities. Medical records of 238 dogs presented within 2 years (2003-2004) with neurological deficits resulting from intervertebral disk disease and surgical treatment at the Department of Small Animal Medicine and Surgery of the University of Veterinary Medicine Hannover were reviewed. 85% of the patients showed a good and 15% a poor long-term functional outcome. Both the presence of deep pain sensation and the weight of the dog were the only variables detected as having a significant impact on prognosis. The time needed to motor function improve depended on the degree of neurological deficits before surgery, and patients with a cervical lesion had a more rapid recovery than patients with a thoracolumbal disease. All other variables, including age, previous signs of intervertebral disk disease, preoperative steroid medication, a lower motor neuron involvement and durotomy did not significantly influence the outcome. Radiographic changes of the vertebral column such as spondylosis, spondylarthrosis, a narrowed disk space up to a fusion of the vertebral bodies mostly were found at the site of a removed intervertebral disk. In dogs with intervertebral disk disease evaluated in the current study a good result could be obtained after surgical decompression.  相似文献   

Ocular immunology in equine recurrent uveitis     

Cornelia A. Deeg 《Veterinary ophthalmology》2008,11(S1):61-65

Equine recurrent uveitis (ERU) is a disease with high prevalence and relevance for the equine population, since it results in blindness. Over the last decade, important advancements have been made in our understanding of the underlying immune responses in this disease. ERU is mediated by an autoaggressive Th1 response directed against several retinal proteins. Interphotoreceptor-retinoid binding protein (IRBP) and cellular retinaldehyde-binding protein (CRALBP) are capable to induce ERU-like disease in experimental horses, with the unique possibility to activate relapses in a well-defined manner. Further, proteomic evidence now suggests that retinal Mueller glial cells (RMG) may play a fatal role in uveitic disease progression by directly triggering inflammation processes through the expression and secretion of interferon-γ. Ongoing relapses in blind eyes can be associated with stable expression of the major autoantigens in ERU retinas. This review briefly summarizes the most significant developments in uveitis immune response research.  相似文献   

Granulocytic anaplasmosis in 63 dogs: clinical signs,laboratory results,therapy and course of disease          下载免费PDF全文

A. Chirek  C. Silaghi  K. Pfister  B. Kohn 《The Journal of small animal practice》2018,59(2):112-120

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