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排序方式: 共有407条查询结果,搜索用时 15 毫秒
351.
Cardoso MV Scarcelli E Grasso LM Teixeira SR Genovez ME 《Animal reproduction science》2000,63(3-4):137-143
The species Ureaplasma diversum is associated with bovine reproductive illnesses, in particular granular lesions of the vulva and vagina or granular vulvovaginitis (GVV). In Brazil, this pathology is unknown and, until this point in time, the presence of U. diversum in the Brazilian herds has been ignored. With the intention of detecting the microorganism, vulvovaginal mucuses of 152 animals located on seven farms in the S?o Paulo State, Brazil were analyzed. Those animals had evidence of reproductive disorders at the time of the sample collection. The technique used for microorganism detection was bacterial isolation. Statistical analysis assessed: the exposure of studied farms to U. diversum, relative risks for different symptoms, susceptibility of the animals according to age and breed. The frequency of that microorganism in tested animals was 38.8% and this frequency suggests that U. diversum can be related to GVV in Brazilian herds and possibly with other reproductive illnesses. As a result, the U. diversum differential diagnosis could be very important. 相似文献
352.
Magro G Perris R Romeo R Marcello M Lopes M Vasquez E Grasso S 《The Histochemical journal》2001,33(4):221-226
The human mesonephros is currently regarded as a simplified version of the foetal metanephros, primarily due to the close morphological resemblance between these two structures. The aim of the present study was to define whether human mesonephric and foetal metanephric nephrons share immunophenotypical traits in their corresponding structures (glomeruli, proximal and distal tubules). For this purpose we first investigated immunohistochemically the overall expression and topographical distribution of cytokeratins 7, 8, 18, 19, and 20, vimentin and -smooth muscle actin in mature mesonephric nephrons and compared the results with those obtained in maturing-stage foetal metanephric nephrons. No expression of cytokeratins 7 and 20 was found. Cytokeratins 8, 18, and 19 and vimentin showed a restricted and basically coincident expression along the different components of both mesonephric and metanephric nephrons. These findings indicate that the intermediate filament protein profile of human mature mesonephric nephrons closely recapitulates that observed in developing metanephros and thereby strengthens the concept that human mesonephros, a transient ontogenic structure, is largely similar to the foetal metanephros.The sole difference between human mesonephros and foetal metanephros was the divergent expression of -smooth muscle actin. This protein exhibited an increasingly accentuated mesangial expression paralleling the morphological maturation of metanephric glomerulus, whereas it was absent from the mesonephric one. This would suggest that the mesangial cells in these two renal structures have a different function during the foetal life. 相似文献
353.
354.
Dott. Vincenzo Grasso 《Plant biosystems》2013,147(1-2):279-289
Riassunto Si descrivono modificazioni morfologiche e anatomiche di un melo (Pirus Malus) cresciuto su una montagna del Sannio (Montagnola di Civitanova) in un ambiente molto sfavorevole per gli eccessi o difetti di temperature. Si premette una descrizione anatomica del fusto e in seguito si trattano vari casi di cicatrizzazione di ferite semplici e complesse. In ultimo si esaminano alcune saldature naturali di rametti e concrescimenti che sono molto frequenti e morfologicamente importanti. Gli agenti che hanno provocato queste strutture anomali del melo sia sulla chionia sia nello sviluppo sono: vento, fieddo, caldo, e morsicature di animali superiori, specialmente di vacche, che sulla Montagnola durante l'estate sono raccolte in numerosi greggi. 相似文献
355.
Luigino Grasso Romain Wyss Joachim Piguet Michael Werner Ghérici Hassa?ne Ruud Hovius Horst Vogel 《PloS one》2013,8(8)
Cellular signaling is classically investigated by measuring optical or electrical properties of single or populations of living cells. Here we show that ligand binding to cell surface receptors and subsequent activation of signaling cascades can be monitored in single, (sub-)micrometer sized native vesicles with single-molecule sensitivity. The vesicles are derived from live mammalian cells using chemicals or optical tweezers. They comprise parts of a cell’s plasma membrane and cytosol and represent the smallest autonomous containers performing cellular signaling reactions thus functioning like minimized cells. Using fluorescence microscopies, we measured in individual vesicles the different steps of G-protein-coupled receptor mediated signaling like ligand binding to receptors, subsequent G-protein activation and finally arrestin translocation indicating receptor deactivation. Observing cellular signaling reactions in individual vesicles opens the door for downscaling bioanalysis of cellular functions to the attoliter range, multiplexing single cell analysis, and investigating receptor mediated signaling in multiarray format. 相似文献
356.
Lisa Dovere Stefania Fera Margherita Grasso Dante Lamberti Cesare Gargioli Barbara Muciaccia Anna Maria Lustri Mario Stefanini Elena Vicini 《PloS one》2013,8(4)
In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell population found on the basal membrane of the seminiferous tubules. A large body of evidence has demonstrated that glial cell line-derived neurotrophic factor (GDNF), a Sertoli-derived factor, is essential for in vivo and in vitro stem cell self-renewal. However, the mechanisms underlying this activity are not completely understood. In this study, we show that GDNF induces dose-dependent directional migration of freshly selected undifferentiated spermatogonia, as well as germline stem cells in culture, using a Boyden chamber assay. GDNF-induced migration is dependent on the expression of the GDNF co-receptor GFRA1, as shown by migration assays performed on parental and GFRA1-transduced GC-1 spermatogonial cell lines. We found that the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP) is specifically expressed in undifferentiated spermatogonia. VASP belongs to the ENA/VASP family of proteins implicated in actin-dependent processes, such as fibroblast migration, axon guidance, and cell adhesion. In intact seminiferous tubules and germline stem cell cultures, GDNF treatment up-regulates VASP in a dose-dependent fashion. These data identify a novel role for the niche-derived factor GDNF, and they suggest that GDNF may impinge on the stem/progenitor compartment, affecting the actin cytoskeleton and cell migration. 相似文献
357.
The olive oil phenol hydroxytyrosol (3), as well its metabolite homovanillic alcohol (4), were subjected to chemoselective lipase-catalysed acylations, affording with good yield 10 derivatives (5-14) bearing C(2), C(3), C(4), C(10) and C(18) acyl chains at C-1. Hydroxytyrosol (3) and its lipophilic derivatives showed very good DPPH. radical scavenging activity. Compounds 3, 4 and their lipophilic analogues 5-14 were subjected to the atypical Comet test on whole blood cells: 3 and its analogues 5 and 6, with little hydrophobic character (logP相似文献
358.
Keith J. Mickolajczyk Patrick M.M. Shelton Michael Grasso Xiaocong Cao Sara E. Warrington Amol Aher Shixin Liu Tarun M. Kapoor 《Biophysical journal》2021,120(6):1020-1030
The superfamily 1 helicase nonstructural protein 13 (nsp13) is required for SARS-CoV-2 replication. The mechanism and regulation of nsp13 has not been explored at the single-molecule level. Specifically, force-dependent unwinding experiments have yet to be performed for any coronavirus helicase. Here, using optical tweezers, we find that nsp13 unwinding frequency, processivity, and velocity increase substantially when a destabilizing force is applied to the RNA substrate. These results, along with bulk assays, depict nsp13 as an intrinsically weak helicase that can be activated >50-fold by piconewton forces. Such force-dependent behavior contrasts the known behavior of other viral monomeric helicases, such as hepatitis C virus NS3, and instead draws stronger parallels to ring-shaped helicases. Our findings suggest that mechanoregulation, which may be provided by a directly bound RNA-dependent RNA polymerase, enables on-demand helicase activity on the relevant polynucleotide substrate during viral replication. 相似文献
359.
Graziano Fiorito Andrea Affuso David B. Anderson Jennifer Basil Laure Bonnaud Giovanni Botta Alison Cole Livia D’Angelo Paolo De Girolamo Ngaire Dennison Ludovic Dickel Anna Di Cosmo Carlo Di Cristo Camino Gestal Rute Fonseca Frank Grasso Tore Kristiansen Michael Kuba Fulvio Maffucci Arianna Manciocco Felix Christopher Mark Daniela Melillo Daniel Osorio Anna Palumbo Kerry Perkins Giovanna Ponte Marcello Raspa Nadav Shashar Jane Smith David Smith António Sykes Roger Villanueva Nathan Tublitz Letizia Zullo Paul Andrews 《Invertebrate neuroscience : IN》2014,14(1):13-36
Cephalopods have been utilised in neuroscience research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentiation) and anatomical features facilitating physiological studies (e.g. squid giant axon and synapse). On 1 January 2013, research using any of the about 700 extant species of “live cephalopods” became regulated within the European Union by Directive 2010/63/EU on the “Protection of Animals used for Scientific Purposes”, giving cephalopods the same EU legal protection as previously afforded only to vertebrates. The Directive has a number of implications, particularly for neuroscience research. These include: (1) projects will need justification, authorisation from local competent authorities, and be subject to review including a harm-benefit assessment and adherence to the 3Rs principles (Replacement, Refinement and Reduction). (2) To support project evaluation and compliance with the new EU law, guidelines specific to cephalopods will need to be developed, covering capture, transport, handling, housing, care, maintenance, health monitoring, humane anaesthesia, analgesia and euthanasia. (3) Objective criteria need to be developed to identify signs of pain, suffering, distress and lasting harm particularly in the context of their induction by an experimental procedure. Despite diversity of views existing on some of these topics, this paper reviews the above topics and describes the approaches being taken by the cephalopod research community (represented by the authorship) to produce “guidelines” and the potential contribution of neuroscience research to cephalopod welfare. 相似文献
360.
Alessia Mori Natale E. Baldaccini Mariella Baratti Chiara Caccamo Francesco Dessì‐Fulgheri Rosario Grasso Said Nouira Ridha Ouni Enrica Pollonara Felipe Rodriguez‐Godoy Maria T. Spena Dimitri Giunchi 《Ibis》2014,156(3):687-692
The Eurasian Stone‐curlew is a species of conservation concern in Europe. We investigate for the first time the extent of population structure among populations sampled from six geographical areas, representing four subspecies inhabiting the western part of the species' distribution. Neither mitochondrial nor nuclear markers fully supported current subspecies boundaries. However, both markers support significant differentiation of the Canary Island populations from those sampled from the Mediterranean. Further work is needed to establish the taxonomic status of this potentially distinct Macaronesian taxon. More broadly, further genetic research is required to design and implement an effective conservation plan for this species. 相似文献