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1.
Theonella swinhoei is a fairly common inhabitant of reefs throughout the Indian and Pacific Oceans. Metabolomic analyses of samples of T. swinhoei collected in different depths in the Gulf of Aqaba revealed two chemotypes differing in the profiles of the theonellamides they produce, some of which seem to be unknown. Driven by this finding, we examined a sample of T. swinhoei collected more than 40 years ago in the southern part of the Gulf of Aqaba. Large-scale extract of this sample yielded four theonellamides, the known theopalauamide (4), as the major component, and three new metabolites, theonellamide J (1), 5-cis-Apoa-theopalauamide (2), and theonellamide K (3), as the minor components. The planar structure of these complex cyclic glycopeptides was elucidated by combination of 1D and 2D NMR techniques and HRESIMS. The absolute configuration of the amino acids was established by Marfey’s and advanced Marfey’s methods, and the absolute configuration of its galactose unit using “Tanaka’s method” for monosaccharides. The biological activity of the pure compounds was tested for antibacterial activity and for cytotoxicity to HTC-116 cell line. The compounds presented significant cytotoxicity against the HTC-116 cell line, illuminating the importance of the Apoa subunit for the activity. 相似文献
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OBJECTIVE: To determine in vitro vasoactive potency of monoamines formed in the cecum and found in the systemic circulation of horses. SAMPLE POPULATION: Segments of digital blood vessels obtained from 6 healthy mixed-breed horses and ponies euthanatized at an abattoir and platelets isolated from 4 healthy ponies. PROCEDURE: Paired rings of digital artery and vein from the same horse were examined, and isometric tension was recorded. Concentration-response curves for tryptamine (TRP), tyramine (TYR), phenylethylamine (PEA), isoamylamine (IAA), and isobutylamine (IBA) were obtained. Vasoconstrictor mechanisms were investigated for TRP and TYR by the use of antagonists. Washed platelets loaded with [3H]-5-hydroxytryptamine (5-HT) were incubated with monoamines; the amount of radioactivity displaced after 30 minutes was estimated. RESULTS: TRP, TYR, and PEA were potent constrictors of arteries and veins, with TRP and TYR being more potent in veins than arteries. Constrictions induced by TYR were inhibited by benextramine (alpha-antagonist) and nisoxetine (neuronal-uptake blocker), whereas TRP responses were inhibited by ketanserin (5-HT receptor antagonist). All 5 amines displaced 5-HT from platelets with the order of potency being TYR > TRP > PEA > IAA > IBA. CONCLUSIONS AND CLINICAL RELEVANCE: Amines from the equine cecum cause digital vasoconstriction. The most potent (TRP and TYR) cause selective venoconstriction. Tyrosine activates predominantly alpha-adrenoceptors through the release of neuronal norepinephrine, whereas TRP activates 5-HT receptors. All amines tested released 5-HT from platelets. Amines formed in the cecum and released into the systemic circulation warrant additional investigation as trigger factors for digital ischemia and subsequent laminitis. 相似文献
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ABSTRACT Sweet pepper-Leveillula taurica microclimate relations were studied under controlled conditions and in commercial greenhouses. Conidial germination occurred at 10 to 37 degrees C and was optimal at 20 degrees C. Conidial viability declined as temperatures increased to 40 degrees C for 6 h. Leaf colonization was optimal at 15 to 25 degrees C. Severe leaf infections occurred at 15 to 20 degrees C and conidiation was suppressed at 20 to 25 degrees C. Highest germination rates were observed at 75 to 85% relative humidity (RH). Severity of leaf coverage by symptoms was high for plants which were subjected to longer periods of temperatures between 10 to 15 degrees C and daytime RH between 85 to 95%, and positively correlated with nighttime RH. Disease severity was negatively correlated with lengthy periods of temperatures >25 degrees C, day and night average temperatures, and average daytime RH. Conversely, leaf shedding was relatively high under conditions characterized by long periods of temperatures >20 degrees C and <13 degrees C, and positively correlated with average daytime temperatures and periods of RH <75%. Increasing nighttime temperatures by heating and daytime temperatures by closing the greenhouse side walls reduced disease in two commercial greenhouse experiments. A midseason shift from a cooler greenhouse climate to warm daytime climate halted epidemic development. Flower number and yield were reduced in infected crops. 相似文献
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Menzies-Gow NJ Bailey SR Berhane Y Brooks AC Elliott J 《American journal of veterinary research》2008,69(3):349-355
OBJECTIVE: To determine the effect of endotoxin (lipopolysaccharide [LPS]) on vasoactive mediator production by cultured equine digital vein endothelial cells (EDVECs). SAMPLE POPULATION: EDVECs obtained from forelimb digital veins of 7 healthy adult horses. PROCEDURES: EDVECs were incubated with or without LPS (1 microg/mL) for 0, 2, 4, 6, 22, and 24 hours. The EDVECs were incubated for 18 hours with LPS (10 pg/mL to 1 microg/mL) with or without ibuprofen, cycloheximide, or L-nitroarginine methyl ester. Medium concentrations of prostacyclin, cyclic guanosine monophosphate, endothelin-1, and thromboxane A(2) were determined. Changes in inducible nitric oxide synthase and cyclooxygenase-2 expression were determined. RESULTS: LPS stimulated mean 4.2- and 14.1-fold increases in EDVEC prostacyclin and cyclic guanosine monophosphate production, respectively, after 22 hours. These effects were LPS concentration-dependent (LPS concentrations that induced a response halfway between the maximum response and baseline of 1.50 and 1.22 ng/mL, respectively). The LPS-induced cyclic guanosine monophosphate production was significantly inhibited (to basal concentrations) by L-nitroarginine methyl ester, and prostacyclin production was inhibited by cycloheximide and ibuprofen. Production of thromboxane A(2) by EDVECs was not detected. Endothelin-1 accumulated in the medium, but LPS did not enhance its production. Inducible nitric oxide synthase expression in EDVECs was not detected with the available antibodies, whereas LPS stimulated cyclooxygenase-2 expression in a time- and concentration-dependent manner. CONCLUSIONS AND CLINICAL RELEVANCE: LPS stimulated vasoactive mediator production by equine endothelial cells, which may play a role in LPS-induced digital hypoperfusion. 相似文献
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Jos Abel Fernndez Romero María Gabriela Paglini Christine Priano Adolfina Koroch Yoel Rodríguez James Sailer Natalia Teleshova 《Marine drugs》2021,19(12)
Lectins are proteins with a remarkably high affinity and specificity for carbohydrates. Many organisms naturally produce them, including animals, plants, fungi, protists, bacteria, archaea, and viruses. The present report focuses on lectins produced by marine or freshwater organisms, in particular algae and cyanobacteria. We explore their structure, function, classification, and antimicrobial properties. Furthermore, we look at the expression of lectins in heterologous systems and the current research on the preclinical and clinical evaluation of these fascinating molecules. The further development of these molecules might positively impact human health, particularly the prevention or treatment of diseases caused by pathogens such as human immunodeficiency virus, influenza, and severe acute respiratory coronaviruses, among others. 相似文献
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Cesar García-Hernández Javier Arece-García Rolando Rojo-Rubio German David Mendoza-Martínez Benito Albarrán-Portillo José Fernando Vázquez-Armijo Leonel Avendaño-Reyes Agustín Olmedo-Juárez Carine Marie-Magdeleine Yoel López-Leyva 《Tropical animal health and production》2017,49(1):55-61
Forty-five Pelibuey sheep were experimentally infested with nematodes to evaluate the effect of three free condensed tannin (FCT) levels of Lysiloma acapulcensis on fecal egg counts (FECs), packed cell volumes (PCV), ocular mucosa colors (OMC), average daily gain (ADG), and adult nematode count. Five treatments were used: 12.5, 25.0, and 37.5 mg of FCT kg?1 of body weight (BW); sterile water (control); and ivermectine (0.22 mg kg?1 of BW) as chemical group. The data were processed through repeated measurement analysis. Even though the three FCT doses decreased (P?<?0.05) the FEC, the highest reduction was obtained with 37.5 mg kg?1 of BW. No differences were observed in PCV and OMC. Higher ADG (P?<?0.05) was observed with 37.5 mg kg?1 of BW of FCT. The count of adult nematodes (females and males) in the higher dose of FCT was similar to chemical treatment. Dose of 37.5 mg kg?1 of BW decreased the parasite infection and improved the lamb performance. Therefore, this dose could be used as a nutraceutic product in sheep production. 相似文献
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Methods for induced spawning and artificial incubation of Tilapia nilotica and T. aurea are described. These methods were required for the production, in aquaria, of F1 hybrids between the two species. Spawning families were established in long aquaria from which sexually ripe individuals were selected for stripping by their “on heat” display coloration. Injections of pituitary hormones were not required. The fertilized eggs were incubated in a low speed “shaker”. At correct temperatures Tilapia fry may be produced by this artificial process all year round. 相似文献
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Crisostomos I. Dovas Efstathios Hatziloukas Raphael Salomon Erhard Barg Yoel Shiboleth Nikolaos I. Katis 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(7):677-684
A survey identified viruses infecting garlic, leek and onion crops and wild Allium species in Greece. Virus identification was based on ELISA, immunoelectron microscopy, and occasionally on RT-PCR. Samples of cultivated Allium species were collected from five districts, whereas samples of twenty-seven wild Allium species were also collected from all over Greece. Onion yellow dwarf
virus (OYDV) and Leek yellow stripe virus (LYSV) were identified in 98.5% and 83.7% of all samples, respectively, and were found in all regions. Allexiviruses were also detected in all regions and their incidence ranged from 62.5% to 70.5% (depending on region and type of allexivirus). Garlic common latent virus (GCLV) was detected in samples from Arcadia (97.6%) and Evia (18.0%) and in one field in Larissa (23.0%). Shallot latent virus (SLV) was found only in two areas (Evros and Theva) and in fields planted with imported propagative material, from Iran and China. The incidence of virus-like symptoms in leek crops ranged from 10.0% to 90.0% in different regions and fields and all symptomatic plants were found to be infected by LYSV. Onion yellow dwarf virus was only found in seven symptomatic onion samples from southern Greece. Allium ampeloprasum spp. ampeloprasum and Allium flavum, were the only wild Allium species found to be infected with LYSV. Finally Turnip mosaic virus (TuMV) was found in A. sphaerocephalon, A. guttatum, A. subhirsutum, and A. neapolitanum. 相似文献