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51.
Amanda dos Santos Marina Tenório Botelho Willian Reina Joviano Vicente Gomes José Roberto Machado Cunha da Silva Gisela de Aragão Umbuzeiro 《Invertebrate Biology》2023,142(1):e12394
Hemocytes are circulating blood cells that play a crucial function in amphipods and other crustacean immune systems. The hemocytes of the marine tropical amphipod Parhyale hawaiensis have been used for the evaluation of DNA damage and micronuclei, but they have not been characterized in the scientific literature. The aim of this study was to describe the hemolymph cells of P. hawaiensis and study their phagocytotic activity. Basic dyes were used to differentiate the cell types and the presence of lipids. The total hemocyte counts (THCs) and the proportion and sizes of the hemocyte types were determined. Hemolymph was exposed to Escherichia coli for verification of the presence of phagocytosis. Three cell types, all containing lipids, were identified in P. hawaiensis: granulocytes (oval shape, 13.4 × 7.6 μm), semi-granulocytes (oval shape, 14.1 × 7.2 μm), and hyalinocytes (round shape, 9.6 × 7.2 μm). Those three cell types were found in different percentages in males (64.8%, 31.1%, and 4.2%) and females (70.1%, 28.2%, and 1.7%). THCs for males were 9007 ± 3800 cells per individual and 4695 ± 1892 cells per individual for females. The cells of E. coli were phagocytized by the hemocytes. Our findings increased the knowledge of hemocytes in P. hawaiensis and is a step forward in using hemocyte-based immune responses as an endpoint in ecotoxicology. 相似文献
52.
Simone Prospero Malve Heinz Eva Augustiny Ying-Yu Chen Juanita Engelbrecht Marina Fonti Aliona Hoste Beat Ruffner Romina Sigrist Noelani van den Berg Patrick Fonti 《Environmental microbiology》2023,25(11):2250-2265
Emerging diseases caused by both native and exotic pathogens represent a main threat to forest ecosystems worldwide. The two invasive soilborne pathogens Phytophthora cinnamomi and Phytophthora × cambivora are the causal agents of ink disease, which has been threatening Castanea sativa in Europe for several centuries and seems to be re-emerging in recent years. Here, we investigated the distribution, causal agents, and infection dynamics of ink disease in southern Switzerland. A total of 25 outbreaks were identified, 19 with only P. cinnamomi, 5 with only P. × cambivora, and 1 with both species. Dendrochronological analyses showed that the disease emerged in the last 20–30 years. Infected trees either died rapidly within 5–15 years post-infection or showed a prolonged state of general decline until death. Based on a generalized linear model, the local risk of occurrence of ink disease was increased by an S-SE aspect of the chestnut stand, the presence of a pure chestnut stand, management activities, the proximity of roads and buildings, and increasing annual mean temperature and precipitation. The genetic structure of the local P. cinnamomi population suggests independent introductions and local spread of the pathogen. 相似文献
53.
Many tropical animals inhabit mosaic landscapes including human-modified habitat. In such landscapes, animals commonly adjust feeding behavior, and may incorporate non-natural foods. These behavioral shifts can influence consumers' nutritional states, with implications for population persistence. However, few studies have addressed the nutritional role of non-natural food. We examined nutritional ecology of wild blue monkeys to understand how dietary habits related to non-natural foods might support population persistence in a mosaic landscape. We documented prevalence and nutritional composition of non-natural foods in monkey diets to assess how habitat use influenced their consumption, and their contribution to nutritional strategies. While most energy and macronutrients came from natural foods, subjects focused non-natural feeding activity on five exotic plants, and averaged about a third of daily calories from non-natural foods. Most non-natural food calories came from non-structural carbohydrates and least from protein. Consumption of non-natural foods related to time in human-modified habitats, which two groups used non-randomly. Non-natural and natural foods were similar in nutrients, and the amount of non-natural food consumed drove variation in nutritional strategy. When more daily calories came from non-natural foods, females consumed a higher ratio of non-protein energy to protein (NPE:P). Females also prioritized protein while allowing NPE:P to vary, increasing NPE while capitalizing on non-natural foods. Overall, these tropical mammals achieved a similar nutrient balance regardless of their intake of non-natural foods. Forest and forest-adjacent areas with non-natural vegetation may provide adequate nutrient access for consumers, and thus contribute to wildlife conservation in mosaic tropical landscapes. 相似文献
54.
Janaine Almeida Neto Daniel Amando Nery Katia Simoni Bezerra Lima Maria Eduarda Gomes da Cruz Silva Tarcísio Cícero de Lima Araújo Nathália Andrezza Carvalho de Souza Rodolfo Hideki Vicente Nishimura Camila de Souza Araújo Ana Paula de Oliveira Jackson Roberto Guedes da Silva Almeida Larissa Araújo Rolim 《化学与生物多样性》2023,20(3):e202201039
This article describes the phytochemical study of Cannabis sativa roots from northeastern Brazil. The dried plant material was pulverized and subjected to exhaustive maceration with ethanol at room temperature, obtaining the crude ethanolic extract (Cs-EEBR). The volatile compounds were analyzed by gas chromatography coupled with mass spectrometry (GC/MS), which allowed to identify 22 compounds by comparing the linear retention index (LRI), the similarity index (SI) and the fragmentation pattern of the constituents with the literature. By this technique the major compounds identified were: friedelan-3-one and β-sitosterol. In addition, two fractions were obtained from Cs-EEBR by classical column chromatography and preparative thin layer chromatography. These fractions were analyzed by NMR and IR and together with the mass spectrometry data allowed to identify the compounds: epifriedelanol, friedelan-3-one, β-sitosterol and stigmasterol. The study contributed to the phytochemical knowledge of Cannabis sativa, specifically the roots, as there are few reports on the chemical constituents of this part of the plant. 相似文献
55.
Viviane Fátima de Oliveira Lucas Figueiredo Gabriel de Oliveira Correia Maria de Fátima Pires da Silva Machado Hugo Zeni Neto Wanderley Dantas dos Santos Claudete Aparecida Mangolin 《Global Change Biology Bioenergy》2023,15(12):1465-1476
The burgeoning cellulosic ethanol industry necessitates advancements in enzymatic saccharification, effective pretreatments for lignin removal, and the cultivation of crops more amenable to saccharification. Studies have demonstrated that natural inhibitors of lignin biosynthesis can enhance the saccharification of lignocellulose, even in tissues generated several months post-treatment. In this study, we applied daidzin (a competitive inhibitor of coniferaldehyde dehydrogenase), piperonylic acid (a quasi-irreversible inhibitor of cinnamate 4-hydroxylase), and methylenedioxy cinnamic acid (a competitive inhibitor of 4-coenzyme A ligase) to 60-day-old crops of two conventional Brazilian sugarcane cultivars and two energy cane clones, bred specifically for enhanced biomass production. The resultant biomasses were evaluated for lignin content and enzymatic saccharification efficiency without additional lignin-removal pretreatments. The treatments amplified the production of fermentable sugars in both the sugarcane cultivars and energy cane clones. The most successful results softened the most recalcitrant lignocellulose to the level of the least recalcitrant of the biomasses tested. Interestingly, the softest material became even more susceptible to saccharification. 相似文献
56.
Giovanna Cacciapuoti Maria Angela Moretti Sabrina Forte Assunta Brio Laura Camardella Vincenzo Zappia Marina Porcelli 《European journal of biochemistry》2004,271(23-24):4834-4844
The extremely heat-stable 5'-methylthioadenosine phosphorylase from the hyperthermophilic archaeon Pyrococcus furiosus was cloned, expressed to high levels in Escherichia coli, and purified to homogeneity by heat precipitation and affinity chromatography. The recombinant enzyme was subjected to a kinetic analysis including initial velocity and product inhibition studies. The reaction follows an ordered Bi-Bi mechanism and phosphate binding precedes nucleoside binding in the phosphorolytic direction. 5'-Methylthioadenosine phosphorylase from Pyrococcus furiosus is a hexameric protein with five cysteine residues per subunit. Analysis of the fragments obtained after digestion of the protein alkylated without previous reduction identified two intrasubunit disulfide bridges. The enzyme is very resistant to chemical denaturation and the transition midpoint for guanidinium chloride-induced unfolding was determined to be 3.0 M after 22 h incubation. This value decreases to 2.0 M in the presence of 30 mM dithiothreitol, furnishing evidence that disulfide bonds are needed for protein stability. The guanidinium chloride-induced unfolding is completely reversible as demonstrated by the analysis of the refolding process by activity assays, fluorescence measurements and SDS/PAGE. The finding of multiple disulfide bridges in 5'-methylthioadenosine phosphorylase from Pyrococcus furiosus argues strongly that disulfide bond formation may be a significant molecular strategy for stabilizing intracellular hyperthermophilic proteins. 相似文献
57.
Marina S. Trofimova Inna M. Zhestkova Valentina P. Kholodova Igor M. Andreev Evgeny M. Sorokin Anna G. Kruglova Vladimir V. Kuznetsov 《Physiologia plantarum》2003,118(2):232-239
The osmotic water permeability ( P os ) of cell membranes isolated from leaves of 40-, 50- and 60-day-old Mesembryanthemum crystallinum plants was estimated by measuring light-scattering kinetics using stopped-flow spectrophotometry. The measurements were performed on the plasma membrane (PM), purified tonoplast (TP), and TP-enriched vesicles. The PM and TP-enriched vesicles were obtained by partitioning the microsomal fraction in an aqueous polymer two-phase system, whereas the purified TP vesicles were prepared by microsomal vesicle flotation on a sucrose cushion. The P os of isolated membranes declined with plant age. The kinetic experiments showed that there was no difference between the P os of the PM and TP isolated from plants of all ages. A 24-h exposure of plants to 400 m M NaCl caused a decline in the P os as well. These findings suggest that, during M. crystallinum transition to CAM, which was induced by plant ageing or salinity, plant osmoregulatory responses included changes in the P os of the leaf-cell membranes. These variations in the P os are discussed in the context of adaptive mechanisms responsible for the maintenance of the water balance in the common ice plant. 相似文献
58.
Abstract: We studied the action of H2 O2 on the exocytosis of glutamate by cerebrocortical synaptosomes. The treatment of synaptosomes with H2 O2 (50–150 µ M ) for a few minutes results in a long-lasting depression of the Ca2+ -dependent exocytosis of glutamate, induced by KCl or by the K+ -channel inhibitor 4-aminopyridine. The energy state of synaptosomes, as judged by the level of phosphocreatine and the ATP/ADP ratio, was not affected by H2 O2 , although a transient decrease was observed after the treatment. H2 O2 did not promote peroxidation, as judged by the formation of malondialdehyde. In indo-1-loaded synaptosomes, the treatment with H2 O2 did not modify significantly the KCl-induced increase of [Ca2+ ]i . H2 O2 inhibited exocytosis also when the latter was induced by increasing [Ca2+ ]i with the Ca2+ ionophore ionomycin. The effects of H2 O2 were unchanged in the presence of superoxide dismutase and the presence of the Fe3+ chelator deferoxamine. These results appear to indicate that H2 O2 , apparently without damaging the synaptosomes, induces a long-lasting inhibition of the exocytosis of glutamate by acting directly on the exocytotic process. 相似文献
59.
60.
Maria Pellegrini Stefano Mammi Marina Gobbo Raniero Rocchi Evaristo Peggion 《Biopolymers》1995,36(4):461-472
The conformation of the head-to-tail cyclic analogue of bradykinin in DMSO was investigated by nmr. Three sets of resonances were detected and fully assigned. These were attributed to the presence of three stable conformers, two of which were exchanging on the nmr time scale. A fourth, incomplete set of resonances was detected but not assigned. The three major conformers differ in the conformation at the three X-Pro bonds present. From nuclear Overhauser effect spectroscopy (NOESY) spectra, three sets of interproton distances were derived and used in NOE-restrained distance geometry calculations. The resulting structures were refined by energy minimization to yield families of structures. Conformer I is characterized by the presence of two type VIb β-turns between Arg1 and Gly4 and between Phe5 and Phe8. The first β-turn is present also in conformer II, while an inverse γ-turn bridging Pro3 is the most pronounced structural feature of conformer III. © 1995 John Wiley & Sons, Inc. 相似文献