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排序方式: 共有377条查询结果,搜索用时 171 毫秒
301.
Eugenia Migliavacca Christelle Golzio Katrin M?nnik Ian Blumenthal Edwin?C. Oh Louise Harewood Jack A. Kosmicki Maria?Nicla Loviglio Giuliana Giannuzzi Loyse Hippolyte Anne?M. Maillard Ali?Abdullah Alfaiz p. European Consortium Mieke M. van Haelst Joris Andrieux James F. Gusella Mark J. Daly Jacques S. Beckmann Sébastien Jacquemont Michael E. Talkowski Nicholas Katsanis Alexandre Reymond 《American journal of human genetics》2015,96(5):784-796
302.
The ultrastructure of the testes in two representatives of the enigmatic taxon Nemertodermatida was studied using transmission
electron microscopy. Nemertoderma westbladi has paired testes, which are delineated by lining cells. Within each testis, different follicles, each surrounded by a membrane-like
structure, are found. Flagellophora apelti has genuinely follicular testes, consisting of several follicles, each containing a certain stage of spermatogenesis. As
the gametes are not enclosed by a structure that can be called a true gonad, the structure of the testes differs from most
bilaterian animals, but resembles the organization of gametogenic areas of ctenophores. Each stage of spermatogenesis in F. apelti is described, enabling the inference of the origin of the structures seen in mature spermatozoa. The overall structure of
the mature spermatozoa is similar in all nemertodermatids and unique within the Metazoa: an elongated head containing the
nucleus; a middle piece containing an axoneme, mitochondrial derivatives and in F. apelti granular derivatives; and a flagellar tail. 相似文献
303.
Li D Baert L De Jonghe M Van Coillie E Ryckeboer J Devlieghere F Uyttendaele M 《Applied and environmental microbiology》2011,77(4):1399-1404
In this study, the inactivating properties of liquid hydrogen peroxide (L-H(2)O(2)), vaporized hydrogen peroxide (V-H(2)O(2)), UV light, and a combination of V-H(2)O(2) and UV light were tested on murine norovirus 1 (MNV-1) and bacteriophages (φX174 and B40-8) as models for human noroviruses. Disinfection of surfaces was examined on stainless steel discs based on European Standard EN 13697 (2001). For fresh-produce decontamination, a mixture of the viruses was inoculated onto shredded iceberg lettuce and treated after overnight incubation at 2°C. According to our results, L-H(2)O(2) (2.1%) was able to inactivate MNV-1 and φX174 on stainless steel discs by approximately 4 log(10) units within 10 min of exposure, whereas for B40-8, 15% of L-H(2)O(2) was needed to obtain a similar reduction in 10 min. Only a marginal reduction (≤1 log(10) unit after 5 min of exposure) by V-H(2)O(2) (2.52%) was achieved for the tested model viruses, although in combination with UV light, a 4-log(10)-unit decrease within 5 min of treatment was observed on stainless steel discs. Similar trends were observed for the decontamination of shredded iceberg lettuce, but the viral decline was reduced. These results demonstrated that both L-H(2)O(2) and a combination of V-H(2)O(2) and UV light can be used for norovirus inactivation on surfaces; V-H(2)O(2) (2.52%) in combination with UV light is promising for decontamination of fresh produce with much less consumption of water and disinfectant. 相似文献
304.
Ghassibe-Sabbagh M Desmyter L Langenberg T Claes F Boute O Bayet B Pellerin P Hermans K Backx L Mansilla MA Imoehl S Nowak S Ludwig KU Baluardo C Ferrian M Mossey PA Noethen M Dewerchin M François G Revencu N Vanwijck R Hecht J Mangold E Murray J Rubini M Vermeesch JR Poirel HA Carmeliet P Vikkula M 《American journal of human genetics》2011,88(2):2204-161
Cranial neural crest (CNC) is a multipotent migratory cell population that gives rise to most of the craniofacial bones. An intricate network mediates CNC formation, epithelial-mesenchymal transition, migration along distinct paths, and differentiation. Errors in these processes lead to craniofacial abnormalities, including cleft lip and palate. Clefts are the most common congenital craniofacial defects. Patients have complications with feeding, speech, hearing, and dental and psychological development. Affected by both genetic predisposition and environmental factors, the complex etiology of clefts remains largely unknown. Here we show that Fas-associated factor-1 (FAF1) is disrupted and that its expression is decreased in a Pierre Robin family with an inherited translocation. Furthermore, the locus is strongly associated with cleft palate and shows an increased relative risk. Expression studies show that faf1 is highly expressed in zebrafish cartilages during embryogenesis. Knockdown of zebrafish faf1 leads to pharyngeal cartilage defects and jaw abnormality as a result of a failure of CNC to differentiate into and express cartilage-specific markers, such as sox9a and col2a1. Administration of faf1 mRNA rescues this phenotype. Our findings therefore identify FAF1 as a regulator of CNC differentiation and show that it predisposes humans to cleft palate and is necessary for lower jaw development in zebrafish. 相似文献
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308.
Knoops K Bárcena M Limpens RW Koster AJ Mommaas AM Snijder EJ 《Journal of virology》2012,86(5):2474-2487
Virus-induced membrane structures support the assembly and function of positive-strand RNA virus replication complexes. The replicase proteins of arteriviruses are associated with double-membrane vesicles (DMVs), which were previously proposed to derive from the endoplasmic reticulum (ER). Using electron tomography, we performed an in-depth ultrastructural analysis of cells infected with the prototypic arterivirus equine arteritis virus (EAV). We established that the outer membranes of EAV-induced DMVs are interconnected with each other and with the ER, thus forming a reticulovesicular network (RVN) resembling that previously described for the distantly related severe acute respiratory syndrome (SARS) coronavirus. Despite significant morphological differences, a striking parallel between the two virus groups, and possibly all members of the order Nidovirales, is the accumulation in the DMV interior of double-stranded RNA, the presumed intermediate of viral RNA synthesis. In our electron tomograms, connections between the DMV interior and cytosol could not be unambiguously identified, suggesting that the double-stranded RNA is compartmentalized by the DMV membranes. As a novel approach to visualize and quantify the RNA content of viral replication structures, we explored electron spectroscopic imaging of DMVs, which revealed the presence of phosphorus in amounts equaling on average a few dozen copies of the EAV RNA genome. Finally, our electron tomograms revealed a network of nucleocapsid protein-containing protein tubules that appears to be intertwined with the RVN. This potential intermediate in nucleocapsid formation, which was not observed in coronavirus-infected cells, suggests that arterivirus RNA synthesis and assembly are coordinated in intracellular space. 相似文献
309.
Zilberg D Jones JB Burger MA Nicholls PK Nolan D Crockford M Stephens F 《Diseases of aquatic organisms》2012,100(3):219-230
Mulloway Argyrosomus japonicus is a native fish species in Western Australia, for which aquaculture production has recently been developed. A single cohort was stocked in a cage offshore at Geraldton, Western Australia, at a water depth of 6 m. Fish appeared healthy before stocking. Routine histological analysis was carried out from 10 mo post stocking and until completion of harvest (about 2.5 yr post stocking). No gross pathology was evident. Microscopically, however, granulomatous lesions were present in the kidneys of almost 100% of the fish examined. Enclosed in the granuloma was an aggregate of organisms, 4.2 to 5.4 μm in diameter. Kidney granulomas appeared as multi-focal aggregates. Granulomas at different stages of formation and finally fibrosing granulomas were observed. Granulomas also appeared infrequently in other organs: a few granulomas were found in the liver and spleen and a single granuloma in the heart of one fish. Transmission electron microscopy (TEM) revealed that the organism was composed of 2 cells, an outer cell enclosing an inner cell. The inner cell was surrounded by a double membrane and the outer cell by a single membrane. Cellular material, presumably of parasitic nature, surrounded the outer cell. The organism contained primitive mitochondria and abundant free ribosomes. Small subunit ribosomal DNA (SSU rDNA) sequence obtained by PCR revealed an 84% sequence identity with the myxosporean Latyspora scomberomori. Based on TEM and preliminary molecular results, we suggest that the organism is the extrasporogonic developmental stage of a myxozoan parasite, which failed to form spores in the mulloway host. 相似文献
310.