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151.
Nicole Marie Guedje Pieter A. Zuidema Heinjo During Bernard Foahom Jean Lejoly 《Forest Ecology and Management》2007,240(1-3):1-12
A 2-year demographic field study was carried out on the understorey tree Garcinia lucida in the humid Atlantic forests of South Cameroon. The bark and the seeds of the species are exploited for medicinal purposes and palm wine processing in West and Central Africa. The bark is often removed over almost the entire circumference of the stem, leading to high mortality rates. The goal of the study was to assess the impact of bark harvesting on population structure and dynamics, in order to obtain an indication to what extent the actual harvesting practices can be sustained for longer periods, and to provide information on the future availability of the resource. Comparison of populations that had been subject to different harvest regimes allowed assessment of the effects of G. lucida bark harvesting on population stand structure. In lightly exploited populations, unharvested individuals represented more than the half of the trees (>10 cm DBH), while this was only one-third in heavily exploited stands. The percentage of dead exploited trees (>20 cm DBH) was more than 40 and 70%, for lightly and heavily exploited populations, respectively. This reflects the high intensity of bark harvesting, mainly directed at large trees. For the assessment of bark harvesting on population dynamics, we constructed matrix models for each of the three common bark harvest practices: (1) partial debarking of stem, (2) ring-barking trees and (3) felling trees at approximately 1 m height above ground level to extract bark. For all harvest practices, the asymptotic population growth rates (λ) were not significantly different from 1 indicating that populations were neither growing nor decreasing in size. Nevertheless, model projections showed that the stock of available trees decreased. Under an annual regime of partial debarking of all trees >10 cm DBH, the amount of harvestable trees gradually declined and reached 50% of the initial size after 20 years. For ring-barking and felling trees, the projections showed a sharp drop in the amount of harvestable trees directly after the start of the simulations, and the amount continued to decline below 4% of the initial size under an annual harvest regime. Even after a long time, populations did not recover to their pre-harvest numbers. The stable size of harvested populations predicted by λ values suggest that current harvest practices of bark do not jeopardize the future existence of G. lucida populations. However, as the frequently applied harvest practices of ring-barking and felling strongly reduced the stock in our simulations, commercial bark exploitation cannot be sustained over long periods. Nevertheless, as long as populations can recover from the loss of exploited individuals, by continuous recruitment, there is still prospect for sustained bark extraction. 相似文献
152.
Resveratrol inhibits the activity of equine neutrophil myeloperoxidase by a direct interaction with the enzyme 总被引:2,自引:0,他引:2
Kohnen S Franck T Van Antwerpen P Boudjeltia KZ Mouithys-Mickalad A Deby C Moguilevsky N Deby-Dupont G Lamy M Serteyn D 《Journal of agricultural and food chemistry》2007,55(20):8080-8087
Resveratrol is a polyphenolic antioxidant present in beverage and food known for its multiple protective effects. We report the inhibitory effects of resveratrol on equine myeloperoxidase (MPO), a hemic peroxidase present in the granules of the neutrophils involved in the inflammatory response. Resveratrol inhibited the production of reactive oxygen species (ROS) by stimulated equine neutrophils by acting as a direct scavenger of the ROS released by the cells but did not modify the degranulation of the stimulated neutrophils as the amounts of released MPO were unchanged. Resveratrol strongly inhibited the chlorination, oxidation, and nitration activities of MPO in a dose-dependent manner. By an original technique of specific immunological extraction followed by enzymatic detection (SIEFED), we demonstrated that resveratrol inhibited the peroxidasic activity of the MPO measured by a direct interaction such as the fixation of resveratrol on the enzyme. The observation of a decrease of the accumulation of compound II suggested that resveratrol acts as an electron donor for MPO reduction. 相似文献
153.
Luckschander N Allenspach K Hall J Seibold F Gröne A Doherr MG Gaschen F 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(2):221-227
The goal of this study was to investigate the correlation between perinuclear antineutrophilic cytoplasmic antibody (pANCA) and clinical scores before and after treatment in diarrheic dogs with food-responsive disease (FRD) or inflammatory bowel disease (IBD). pANCA serology was evaluated prospectively by indirect immunofluorescence in 65 dogs with signs of gastrointestinal disease, and if positive, pANCA antibody titers were determined. Thirty-nine dogs with FRD responded to a novel diet, and 26 dogs with IBD were treated with corticosteroids. The severity of clinical signs was scored by means of a canine IBD activity index (CIBDAI). At initial examination, a significantly (P = .002) higher percentage of dogs were pANCA-positive in the FRD group (62%) compared with the IBD group (23%). pANCA titers were significantly higher (P = .003) before treatment in the FRD group (median titer 100) compared with the IBD group (median titer 1). However, there was no difference in pANCA titers between the groups after respective treatments because dogs in the IBD group had a significant increase in pANCA titer after treatment. The CIBDAI score decreased significantly (P < .001) after treatment in both groups (74% moderate to severe in FRD dogs before versus 8% after treatment; 85% moderate to severe in IBD dogs before versus 32% after treatment). There was no correlation between pANCA status in FRD or IBD dogs before treatment and scores for CIBDAI, endoscopy, or histopathology before or after treatment, except for the endoscopic duodenal score in dogs with FRD after treatment (P = .03). A positive pANCA test before therapy may aid in the diagnosis of FRD. 相似文献
154.
Spiegel IB White SD Foley JE Drazenovich NL Ihrke PJ Affolter VK 《Veterinary dermatology》2006,17(1):51-62
Nine horses from ages 5 to 21 years were diagnosed with cutaneous equine sarcoidosis (ES) over an 18-year period. In addition to skin, the lungs were frequently involved, with other organ systems affected less commonly. A predisposition for thoroughbreds and geldings was noted. Cutaneous lesions and signs included crusts, scales, alopecia and pruritus. These were found at various sites, particularly the legs/thighs/elbows, thorax, neck, face and ventral abdomen. Three horses were euthanized shortly after hospitalization; others survived as long as 12 years. Histopathologic stains, immunohistochemistry and polymerase chain reaction assays on paraffin-embedded cutaneous specimens from eight horses for Mycobacterium spp., Coccidioides immitis, Cryptococcus neoformans, Corynebacterium pseudotuberculosis, and Borrelia burgdorferi were all negative. The aetiology of ES is unlikely microbial and continues to be a diagnosis of exclusion. ES, when limited to the skin, is associated with a good prognosis, with either partial or complete response to glucocorticoid therapy in all the surviving horses. 相似文献
155.
Liptak JM Dernell WS Ehrhart N Lafferty MH Monteith GJ Withrow SJ 《Veterinary surgery : VS》2006,35(6):518-533
OBJECTIVE: To compare surgical and oncologic outcome in dogs with osteosarcoma (OSA) of the distal aspect of the radius treated with limb-sparing surgery, using either a cortical allograft or endoprosthesis, and postoperative chemotherapy; and to evaluate predictive factors for outcome. STUDY DESIGN: Prospective cohort study. ANIMALS: Dogs (n = 20) with spontaneous, non-metastatic OSA of the distal aspect of the radius. METHODS: Dogs were prospectively randomized for limb-sparing surgery with either a cortical allograft (n = 10) or endoprosthesis (10) and full-course adjuvant chemotherapy using single or dual agent protocols of cisplatin, carboplatin, and/or doxorubicin. Surgical (intraoperative findings, postoperative infection, construct failure) and oncologic (local tumor recurrence, metastasis, survival) outcomes were compared. The influence of intraoperative and postoperative variables on surgical and oncologic outcome were evaluated. RESULTS: No clinically significant differences in surgical and oncologic outcome were detected between groups. The percentage of radius replaced by the implant was significantly greater in the endoprosthesis group (60.9% compared with 48.6%, P = .008). Median survival time (MST) for dogs with construct failure, regardless of implant type, was 685 days and significantly greater than MST of dogs without construct failure (322 days, P = .042; hazard ratio [HR] 16.82). Median metastasis-free interval and MST (685 days versus 289 days; P = .034, HR 24.58) were significantly greater in dogs with postoperative infection. Disease-free and overall limb-salvage rates were 70% and 85%, respectively. Overall MST was 430 days. CONCLUSIONS: For dogs with OSA of the distal aspect of the radius, a cortical allograft or endoprosthesis can be used for limb-sparing surgery. Construct failure and postoperative infection significantly improve survival time regardless of implant type. CLINICAL RELEVANCE: An endoprosthesis is an attractive alternative to cortical allografts for limb-salvage of the distal aspect of the radius in dogs because surgical and oncologic outcomes are similar, but the endoprosthesis is an immediately available off-the-shelf implant which is not complicated by the bone harvesting and banking requirements associated with cortical allografts. Mechanisms whereby postoperative infection improves survival time requires further investigation and, if elucidated, may provide the opportunity to improve the outcome of dogs and humans with OSA. 相似文献
156.
Borel N Thoma R Spaeni P Weilenmann R Teankum K Brugnera E Zimmermann DR Vaughan L Pospischil A 《Veterinary pathology》2006,43(5):702-708
In 2001, the first case of bovine chlamydial abortion was reported in canton Graubunden, Switzerland. In this region, Chlamydophila (Cp.) abortus is endemic in small ruminants. Hence, we aimed to investigate the incidence of chlamydia-related abortions in cattle from Graubunden. During breeding seasons of 2003-2004, formalin-fixed and paraffin-embedded placenta specimens (n = 235) from late-term abortions in cattle were analyzed by histopathology, immunohistochemistry with a Chlamydiaceae-specific monoclonal antibody against chlamydial lipopolysaccharide (LPS), and 2 different polymerase chain reaction (PCR) methods (16 S ribosomal ribonucleic acid [rRNA] PCR, intergenic spacer [IGS-S] PCR), followed by PCR product sequencing. In 149 of 235 cases (63.4%), histopathologic lesions such as purulent and/or necrotizing placentitis were observed. Chlamydial antigen was clearly demonstrated in immunohistochemistry in only 1 of 235 cases (0.4%). Cp. abortus or Cp. psittaci was found in 12 of 235 (5.1%) and 10 of 235 cases (4.2%) by 16 S rRNA PCR and IGS-S PCR, respectively. However, we detected, by 16 S rRNA PCR, 43 of 235 cases (18.3%) to be positive for chlamydia-like organisms. In contrast to the situation in small ruminants in the canton Graubunden, bovine abortion from Cp. abortus seems not to play an important role. Nevertheless, zoonotic potential should be taken into account when handling abortion material from cattle. The significance of chlamydia-like isolates other than Waddlia chondrophila remains an open question in abortion and needs further investigation. 相似文献
157.
Solimini NL Xu Q Mermel CH Liang AC Schlabach MR Luo J Burrows AE Anselmo AN Bredemeyer AL Li MZ Beroukhim R Meyerson M Elledge SJ 《Science (New York, N.Y.)》2012,337(6090):104-109
Tumors exhibit numerous recurrent hemizygous focal deletions that contain no known tumor suppressors and are poorly understood. To investigate whether these regions contribute to tumorigenesis, we searched genetically for genes with cancer-relevant properties within these hemizygous deletions. We identified STOP and GO genes, which negatively and positively regulate proliferation, respectively. STOP genes include many known tumor suppressors, whereas GO genes are enriched for essential genes. Analysis of their chromosomal distribution revealed that recurring deletions preferentially overrepresent STOP genes and underrepresent GO genes. We propose a hypothesis called the cancer gene island model, whereby gene islands encompassing high densities of STOP genes and low densities of GO genes are hemizygously deleted to maximize proliferative fitness through cumulative haploinsufficiencies. Because hundreds to thousands of genes are hemizygously deleted per tumor, this mechanism may help to drive tumorigenesis across many cancer types. 相似文献
158.
Osterloh JM Yang J Rooney TM Fox AN Adalbert R Powell EH Sheehan AE Avery MA Hackett R Logan MA MacDonald JM Ziegenfuss JS Milde S Hou YJ Nathan C Ding A Brown RH Conforti L Coleman M Tessier-Lavigne M Züchner S Freeman MR 《Science (New York, N.Y.)》2012,337(6093):481-484
Axonal and synaptic degeneration is a hallmark of peripheral neuropathy, brain injury, and neurodegenerative disease. Axonal degeneration has been proposed to be mediated by an active autodestruction program, akin to apoptotic cell death; however, loss-of-function mutations capable of potently blocking axon self-destruction have not been described. Here, we show that loss of the Drosophila Toll receptor adaptor dSarm (sterile α/Armadillo/Toll-Interleukin receptor homology domain protein) cell-autonomously suppresses Wallerian degeneration for weeks after axotomy. Severed mouse Sarm1 null axons exhibit remarkable long-term survival both in vivo and in vitro, indicating that Sarm1 prodegenerative signaling is conserved in mammals. Our results provide direct evidence that axons actively promote their own destruction after injury and identify dSarm/Sarm1 as a member of an ancient axon death signaling pathway. 相似文献
159.
Grossmann K Christiansen N Looser R Tresch S Hutzler J Pollmann S Ehrhardt T 《Pest management science》2012,68(4):494-504
BACKGROUND: For novel herbicides identified in greenhouse screens, efficient research is important to discover and chemically optimise new leads with new modes of action (MoAs). RESULTS: The metabolic and physiological response pattern to a herbicide can be viewed as the result of changes elicited in the molecular and biochemical process chain. These response patterns are diagnostic of a herbicide's MoA. At the starting point of MoA characterisation, an array of bioassays is used for comprehensive physiological profiling of herbicide effects. This physionomics approach enables discrimination between known, novel or multiple MoAs of a compound and provides a first clue to a new MoA. Metabolic profiling is performed with the use of treated Lemna paucicostata plants. After plant extraction and chromatography and mass spectrometry, changes in levels of approximately 200 identified and 300 unknown analytes are quantified. Check for known MoA assignment is performed by multivariate statistical data analyses. Distinct metabolite changes, which can direct to an affected enzymatic step, are visualised in a biochemical pathway view. Subsequent target identification includes metabolite feeding and molecular, biochemical and microscopic methods. CONCLUSION: The value of this cascade strategy is exemplified by new herbicides with MoAs in plastoquinone, auxin or very‐long‐chain fatty acid synthesis. Copyright © 2011 Society of Chemical Industry 相似文献
160.
Borel N Regenscheit N Di Francesco A Donati M Markov J Masserey Y Pospischil A 《Veterinary microbiology》2012,156(1-2):143-146
The aim of this study was to investigate Chlamydia suis in a pig farm with an outbreak of conjunctivitis and diarrhea. Eye swabs and pooled fecal samples were investigated for the presence of C. suis by real-time PCR and ArrayTube microarray. Samples positive for C. suis by ArrayTube microarray assay were further tested for the presence of the tet(C) resistance gene by PCR. In the first examination, C. suis was identified in 12 six-week-old pigs showing conjunctivitis. Of these, the tet(C) gene-coding region was amplified in one pooled fecal sample and one eye swab, respectively. After oral treatment with tetracycline, clinical symptoms disappeared. Subsequently, all eye swabs investigated from 10 healthy pigs were positive for C. suis and the tet(C) gene-coding region. The present study reports rapid selection for tetracycline-resistant C. suis after antibiotic treatment. 相似文献