Particle arrangement and internal porosity of coarse fragments affect water retention in stony soils     

Caroline Andrade Pereira  Rodrigo Pivoto Mulazzani  Quirijn de Jong Van Lier  Fabrício de Araújo Pedron  Paulo Ivonir Gubiani 《European Journal of Soil Science》2023,74(3):e13382

Information about water retention in stony soils lags behind due to methodological difficulties. We applied a new strategy to measure the water retention in soils with coarse fragments (CFs) and to get insights into the effect of CFs porosity on water retention. Water retention at zero, 10, and 150 m suction, bulk density, and the mass fraction of six particle size classes were measured in undisturbed blocks from soils with variable CFs contents, originating from three parent materials. The results showed that some soils contain porous CFs (2–250 mm) with a water holding capacity as high as the fine fraction (<2 mm). The water held in the suction range of 1–150 m in a soil with porous CFs was twice as high as in soils with non-porous CFs. Multilinear regressions revealed that both the water retention capacity at 1 m suction and in the range 1–150 m were more dependent on bulk density than on the fraction of CFs and fine particles. In the soil with porous CFs, there was no correlation between their fraction and soil water retention. These results show that the bulk water retention capacity of soils with CFs is underestimated when not considering the internal porosity of the CFs. A better understanding of the effect of the porosity of CFs on bulk soil porosity and water retention is important to propose suitable pedotransfer functions and refine physically-based hydraulic functions for stony soils.  相似文献   

Electrophysiological Evaluation of Pacific Oyster (Crassostrea gigas) Sensitivity to Saxitoxin and Tetrodotoxin     

Floriane Boullot  Caroline Fabioux  Hlne Hgaret  Pierre Boudry  Philippe Soudant  Evelyne Benoit 《Marine drugs》2021,19(7)

Pacific oysters (Crassostrea gigas) may bio-accumulate high levels of paralytic shellfish toxins (PST) during harmful algal blooms of the genus Alexandrium. These blooms regularly occur in coastal waters, affecting oyster health and marketability. The aim of our study was to analyse the PST-sensitivity of nerves of Pacific oysters in relation with toxin bio-accumulation. The results show that C. gigas nerves have micromolar range of saxitoxin (STX) sensitivity, thus providing intermediate STX sensitivity compared to other bivalve species. However, theses nerves were much less sensitive to tetrodotoxin. The STX-sensitivity of compound nerve action potential (CNAP) recorded from oysters experimentally fed with Alexandrium minutum (toxic-alga-exposed oysters), or Tisochrysis lutea, a non-toxic microalga (control oysters), revealed that oysters could be separated into STX-resistant and STX-sensitive categories, regardless of the diet. Moreover, the percentage of toxin-sensitive nerves was lower, and the STX concentration necessary to inhibit 50% of CNAP higher, in recently toxic-alga-exposed oysters than in control bivalves. However, no obvious correlation was observed between nerve sensitivity to STX and the STX content in oyster digestive glands. None of the nerves isolated from wild and farmed oysters was detected to be sensitive to tetrodotoxin. In conclusion, this study highlights the good potential of cerebrovisceral nerves of Pacific oysters for electrophysiological and pharmacological studies. In addition, this study shows, for the first time, that C. gigas nerves have micromolar range of STX sensitivity. The STX sensitivity decreases, at least temporary, upon recent oyster exposure to dinoflagellates producing PST under natural, but not experimental environment.  相似文献   

Protease Inhibitors from Marine Venomous Animals and Their Counterparts in Terrestrial Venomous Animals     

Caroline B.F. Mour?o  Elisabeth F. Schwartz 《Marine drugs》2013,11(6):2069-2112

The Kunitz-type protease inhibitors are the best-characterized family of serine protease inhibitors, probably due to their abundance in several organisms. These inhibitors consist of a chain of ~60 amino acid residues stabilized by three disulfide bridges, and was first observed in the bovine pancreatic trypsin inhibitor (BPTI)-like protease inhibitors, which strongly inhibit trypsin and chymotrypsin. In this review we present the protease inhibitors (PIs) described to date from marine venomous animals, such as from sea anemone extracts and Conus venom, as well as their counterparts in terrestrial venomous animals, such as snakes, scorpions, spiders, Anurans, and Hymenopterans. More emphasis was given to the Kunitz-type inhibitors, once they are found in all these organisms. Their biological sources, specificity against different proteases, and other molecular blanks (being also K⁺ channel blockers) are presented, followed by their molecular diversity. Whereas sea anemone, snakes and other venomous animals present mainly Kunitz-type inhibitors, PIs from Anurans present the major variety in structure length and number of Cys residues, with at least six distinguishable classes. A representative alignment of PIs from these venomous animals shows that, despite eventual differences in Cys assignment, the key-residues for the protease inhibitory activity in all of them occupy similar positions in primary sequence. The key-residues for the K⁺ channel blocking activity was also compared.  相似文献   

Anti HSV-1 Activity of Halistanol Sulfate and Halistanol Sulfate C Isolated from Brazilian Marine Sponge Petromica citrina (Demospongiae)     

Tatiana da Rosa Guimar?es  Carlos Guillermo Quiroz  Caroline Rigotto  Simone Quintana de Oliveira  Maria Tereza Rojo de Almeida  éverson Miguel Bianco  Maria Izabel Goulart Moritz  Jo?o Luís Carraro  Jorge Alejandro Palermo  Gabriela Cabrera  Eloir Paulo Schenkel  Flávio Henrique Reginatto  Cláudia Maria Oliveira Sim?es 《Marine drugs》2013,11(11):4176-4192

The n-butanol fraction (BF) obtained from the crude extract of the marine sponge Petromica citrina, the halistanol-enriched fraction (TSH fraction), and the isolated compounds halistanol sulfate (1) and halistanol sulfate C (2), were evaluated for their inhibitory effects on the replication of the Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the viral plaque number reduction assay. The TSH fraction was the most effective against HSV-1 replication (SI = 15.33), whereas compounds 1 (SI = 2.46) and 2 (SI = 1.95) were less active. The most active fraction and these compounds were also assayed to determine the viral multiplication step(s) upon which they act as well as their potential synergistic effects. The anti-HSV-1 activity detected was mediated by the inhibition of virus attachment and by the penetration into Vero cells, the virucidal effect on virus particles, and by the impairment in levels of ICP27 and gD proteins of HSV-1. In summary, these results suggest that the anti-HSV-1 activity of TSH fraction detected is possibly related to the synergic effects of compounds 1 and 2.  相似文献   

Diversity in bacterium-host interactions within the species Helicobacter heilmannii sensu stricto     

Myrthe Joosten  Caroline Blaecher  Bram Flahou  Richard Ducatelle  Freddy Haesebrouck  Annemieke Smet 《Veterinary research》2013,44(1):65

Helicobacter (H.) heilmannii sensu stricto (s.s.) is a zoonotic bacterium that naturally colonizes the stomach of dogs and cats. In humans, this microorganism has been associated with gastritis, peptic ulcer disease and mucosa associated lymphoid tissue (MALT) lymphoma. Little information is available about the pathogenesis of H. heilmannii s.s. infections in humans and it is unknown whether differences in virulence exist within this species. Therefore, a Mongolian gerbil model was used to study bacterium-host interactions of 9 H. heilmannii s.s. strains. The colonization ability of the strains, the intensity of gastritis and gene expression of various inflammatory cytokines in the stomach were determined at 9 weeks after experimental infection. The induction of an antrum-dominant chronic active gastritis with formation of lymphocytic aggregates was shown for 7 strains. High-level antral colonization was seen for 4 strains, while colonization of 4 other strains was more restricted and one strain was not detected in the stomach at 9 weeks post infection. All strains inducing a chronic active gastritis caused an up-regulation of the pro-inflammatory cytokine IL-1β in the antrum. A reduced antral expression of H⁺/K⁺ ATPase was seen in the stomach after infection with 3 highly colonizing strains and 2 highly colonizing strains caused an increased gastrin expression in the fundus. In none of the H. heilmannii s.s.-infected groups, IFN-γ expression was up-regulated. This study demonstrates diversity in bacterium-host interactions within the species H. heilmannii s.s. and that the pathogenesis of gastric infections with this microorganism is not identical to that of an H. pylori infection.  相似文献   

Experimental infection of domestic pigeons with pigeon circovirus     

Schmidt V  Schlömer J  Lüken C  Johne R  Biere B  Müller H  Krautwald-Junghanns ME 《Avian diseases》2008,52(3):380-386

Pigeon circovirus (PiCV) infection and young pigeon disease syndrome (YPDS), associated with high morbidity and mortality, have been recognized in young racing pigeons from large portions of Central Europe. There exist a number of data indicating that YPDS is a consequence of PiCV infection and subsequent immunosuppression. In order to prove PiCV to be one of the crucial factors of YPDS, an experimental infection with PiCV was performed under controlled conditions. Twenty-four domestic pigeons (Columba livia forma domestica) were divided into two groups with 12 pigeons each; an infection group and a control group. All birds were between their fourth to eighth week of life. Pigeons in the infection group were infected both intramuscularly and orally with PiCV purified from naturally infected birds, while pigeons in the control group received a placebo. To test a possible influence of the PiCV infection on the immune system, the animals in both groups were vaccinated simultaneously, on the same day, against PMV-1 (Lasovac plus, IDT, Dessau-Tornau, Germany). Weekly virologic testing showed a viraemic period, and excretion of the infection virus, in pigeons in the infection group. Replication of PiCV could be proved on the basis of histologic findings of multiglobular inclusion bodies, mainly observed in macrophages of the bursa of Fabricius. A PiCV, genetically distinct from the experimental virus, was detected in the control group by polymerase chain reaction (PCR) testing, but any histologic findings comparable to the infection group were absent. None of the pigeons revealed clinical signs of illness, or hints that immunosuppression had occurred, regardless of their group. The absence of stressful conditions, considered as a trigger for the development of YPDS, may be responsible for the failure of disease reproduction in our infection model.  相似文献   

In vitro effects of the chemotherapy agent water‐soluble micellar paclitaxel (Paccal Vet) on canine hemangiosarcoma cell lines     

Caroline R. Reckelhoff  Amandine Lejeune  Patrick M. Thompson  Keijiro Shiomitsu 《Veterinary and comparative oncology》2019,17(1):32-41

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Ocular anomalies and holoprosencephaly in a lamb     

Zeiss CJ  Zarfoss MK  Johnson EE  Dubielzig RR 《Veterinary ophthalmology》2008,11(1):30-33

The brain and eyes from a 1-day-old, male mixed-breed lamb with bilateral microphthalmia were examined. Bilateral ventral colobomata of choroid, sclera, retina and optic nerve were accompanied by agenesis of the optic nerve, and dilated lateral and third ventricular cavities that communicated with the subarachnoid space. Abundant neuroretinal tissue extending through the colobomatous defect to retro-orbital connective tissue, the meningeal surface and ventricular system were identified by histologic examination. Positive immunolabeling of these structures for recoverin (a photoreceptor marker) established the retinal origin of ectopic structures. The optic nerve was replaced by a short fibrous stalk containing glial nests. Sections of brainstem revealed extensive architectural disorganization. A developmental abnormality resulting from defective optic nerve and retina compartmentalization, accompanied by abnormalities of midline development consistent with the holoprosencephaly syndrome, was diagnosed. These lesions are consistent with signaling defects in the sonic hedgehog signaling pathway. Genetic and toxic causes of sonic hedgehog signaling defects are discussed.  相似文献   

Gait and electromyographic alterations due to early onset of injury and eventual rupture of the cranial cruciate ligament in dogs: A pilot study     

Caroline P. Adrian  Kevin K. Haussler  Christopher E. Kawcak  Raoul F. Reiser  Cheryl Riegger‐Krugh  Ross H. Palmer  C. Wayne McIlwraith  Robert A. Taylor 《Veterinary surgery : VS》2019,48(3):388-400

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Remission after complete excision of an intramedullary hemangioma with an identifiable tumor plane in a dog     

Amy B. Yanke  Margaret A. Miller  Caroline V. Fulkerson  Kendra Bohn  R. Timothy Bentley 《Veterinary surgery : VS》2019,48(8):1507-1513

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