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61.
Herbert Budzikiewicz Mathias Schäfer Diana Uría Fernández Sandra Matthijs Pierre Cornelis 《Biometals》2007,20(2):135-144
Characteristic fragment ions of the various chromophores of the pyoverdin siderophore family obtained by collision activated
dissociation of the [M+2H]2+ ions are reported allowing unambiguous identification. Tandem mass spectrometrical studies revealed the existence of the
first example of a ferribactin with a succinamide side chain, and they add some information to the problem in which way a
malic acid side chain is attached to the chromophore. 相似文献
62.
Yveta Lhotáková Luká? Plí?til Alena Morávková Pavel Kubát Kamil Lang Jitka Forstová Ji?í Mosinger 《PloS one》2012,7(11)
Novel biomaterials based on hydrophilic polycaprolactone and polyurethane (Tecophilic®) nanofibers with an encapsulated 5,10,5,20-tetraphenylporphyrin photosensitizer were prepared by electrospinning. The doped nanofiber textiles efficiently photo-generate O2(1Δg), which oxidize external chemical and biological substrates/targets. Strong photo-virucidal effects toward non-enveloped polyomaviruses and enveloped baculoviruses were observed on the surface of these textiles. The photo-virucidal effect was confirmed by a decrease in virus infectivity. In contrast, no virucidal effect was detected in the absence of light and/or the encapsulated photosensitizer. 相似文献
63.
Eduardo Blanco-Hernández Pablo Valle-Leija Viviana Zomosa-Signoret René Drucker-Colín Román Vidaltamayo 《PloS one》2012,7(10)
The olfactory system, particularly the olfactory epithelium, presents a unique opportunity to study the regenerative capabilities of the brain, because of its ability to recover after damage. In this study, we ablated olfactory sensory neurons with methimazole and followed the anatomical and functional recovery of circuits expressing genetic markers for I7 and M72 receptors (M72-IRES-tau-LacZ and I7-IRES-tau-GFP). Our results show that 45 days after methimazole-induced lesion, axonal projections to the bulb of M72 and I7 populations are largely reestablished. Furthermore, regenerated glomeruli are re-formed within the same areas as those of control, unexposed mice. This anatomical regeneration correlates with functional recovery of a previously learned odorant-discrimination task, dependent on the cognate ligands for M72 and I7. Following regeneration, mice also recover innate responsiveness to TMT and urine. Our findings show that regeneration of neuronal circuits in the olfactory system can be achieved with remarkable precision and underscore the importance of glomerular organization to evoke memory traces stored in the brain. 相似文献
64.
Ingrid Garzón Victor Carriel Ana Belén Marín-Fernández Ana Celeste Oliveira Juan Garrido-Gómez Antonio Campos María del Carmen Sánchez-Quevedo Miguel Alaminos 《PloS one》2012,7(12)
Temporo-mandibular joint disc disorders are highly prevalent in adult populations. Autologous chondrocyte implantation is a well-established method for the treatment of several chondral defects. However, very few studies have been carried out using human fibrous chondrocytes from the temporo-mandibular joint (TMJ). One of the main drawbacks associated to chondrocyte cell culture is the possibility that chondrocyte cells kept in culture tend to de-differentiate and to lose cell viability under in in-vitro conditions. In this work, we have isolated human temporo-mandibular joint fibrochondrocytes (TMJF) from human disc and we have used a highly-sensitive technique to determine cell viability, cell proliferation and gene expression of nine consecutive cell passages to determine the most appropriate cell passage for use in tissue engineering and future clinical use. Our results revealed that the most potentially viable and functional cell passages were P5–P6, in which an adequate equilibrium between cell viability and the capability to synthesize all major extracellular matrix components exists. The combined action of pro-apoptotic (TRAF5, PHLDA1) and anti-apoptotic genes (SON, HTT, FAIM2) may explain the differential cell viability levels that we found in this study. These results suggest that TMJF should be used at P5–P6 for cell therapy protocols. 相似文献
65.
66.
Mercedes Soriano Luis Cistué María P. Vallés Ana M. Castillo 《Plant Cell, Tissue and Organ Culture》2007,91(3):225-234
The aim of this work was to study the effects of colchicine application on chromosome doubling and androgenic response in
anther and microspore culture of different bread wheat genotypes. Colchicine was applied during a mannitol stress pretreatment
or during the first 48 h of culture at concentrations of 0, 150 and 300 mg l−1. When colchicine was applied during stress pretreatment, the percentage of doubling depended on genotype and concentration.
A significant increase in doubling was observed with 300 mg l−1 in the low androgenic responding cv. Caramba. Colchicine incorporation during the first hours of culture improved percentage
of doubling in all genotypes, in both anther and microspore culture. Application of 300 mg l−1 colchicine improved the percentage of doubling in the two low responding genotypes, to 118% of control in DH24033, and 75%
in Caramba in microspore and anther culture, respectively. Concerning the androgenic response, the effect of colchicine on
embryo formation and percentage of green plants depended on the genotype and on the culture method. In cv. Pavon, a 2- and
a 3-fold increase in percentage of embryogenesis and green plants, respectively, were obtained with 300 mg l−1 colchicine in microspore culture. However, no significant differences in these two variables were observed in anther culture.
The number of green doubled haploid (DH) plants reflects the index of success of the procedure. Regardless of the culture
method, when colchicine was incorporated during the first hours of culture, the number of green DH plants increased significantly
in three of four genotypes. These results confirm the usefulness of colchicine application during the first hours of culture
in wheat breeding programs. 相似文献
67.
Ylenia Chiari Pablo Orozco-terWengel Miguel Vences David R. Vieites Augustin Sarovy Jasmin E. Randrianirina Axel Meyer Edward Louis Jr. 《Conservation Genetics》2006,7(4):473-482
Dyscophus antongilii and D. guineti are two morphologically very similar microhylid frogs from Madagascar of uncertain taxonomy. D. antongilii is currently included in Appendix I of the Convention on the International Trade in Endangered Species (CITES) and its exportation is banned completely. In contrast, D. guineti does not receive any legal protection and it is regularly exported. Field data on ecology and behaviour are to a large extent lacking. Here we report on a genetic survey of D. antongilii and D. guineti using nuclear and mitochondrial DNA markers. Sequences of a fragment of 501 bp of the mitochondrial cytochrome b gene from one population of D. antongilii and two populations of D. guineti resulted in a single haplotype network, without haplotype sharing among the populations. However, haplotypes of D.␣guineti were only 1–4 mutational steps from those of D. antongilii, and did not form a clade. The analysis of eight microsatellites newly developed and standardized for D. antongilii revealed an excess of homozygotes and the absence of Hardy–Weinberg equilibrium. The microsatellite data clearly distinguished between D. antongilii and D. guineti, and fixed differences were observed at one locus. Although confirmation of the status of Dyscophus antongilii and D. guineti as separate species requires further data, our study supports the definition of these two taxa as different evolutionary significant units under the adaptive evolutionary conservation concept. 相似文献
68.
D. Padilla F. Acosta J. A. García F. Real Jose R. Vivas 《Archives of microbiology》2009,191(3):191-198
Hafnia alvei, a Gram negative bacillus related to the Enterobacteriaceae family, is considered an opportunistic pathogen of several animal species and humans. In this communication, we describe
fimbrial-like structures from different strains of H. alvei that cannot be easily ascribed to any of the previously reported fimbrial types in this species (type I or type III). Polymerase
chain reaction (PCR) and immunofluorescence assays were carried out to study fimbriae and flagella in H. alvei strains isolated from different sources. No correlation between the results obtained by PCR and those obtained by phenotypic
methods were found, and the antibodies used gave cross or different recognition patterns of the surface structures present
in these strains. We report as well that strain and growth temperature influence fimbriation and expression of flagella in
human and animal isolates of H. alvei. This study also indicates that the absence of fimbriae have a significant positive influence on the initial adhesion of
H. alvei to human epithelial cells. 相似文献
69.
Christopher A. Fraker Camillo Ricordi Luca Inverardi Juan Domínguez‐Bendala 《Biology of the cell / under the auspices of the European Cell Biology Organization》2009,101(8):431-440
Beyond its role as an electron acceptor in aerobic respiration, oxygen is also a key effector of many developmental events. The oxygen‐sensing machinery and the very fabric of cell identity and function have been shown to be deeply intertwined. Here we take a first look at how oxygen might lie at the crossroads of at least two of the major molecular pathways that shape pancreatic development. Based on recent evidence and a thorough review of the literature, we present a theoretical model whereby evolving oxygen tensions might choreograph to a large extent the sequence of molecular events resulting in the development of the organ. In particular, we propose that lower oxygenation prior to the expansion of the vasculature may favour HIF (hypoxia inducible factor)‐mediated activation of Notch and repression of Wnt/β‐catenin signalling, limiting endocrine cell differentiation. With the development of vasculature and improved oxygen delivery to the developing organ, HIF‐mediated support for Notch signalling may decline while the β‐catenin‐directed Wnt signalling is favoured, which would support endocrine cell differentiation and perhaps exocrine cell proliferation/differentiation. 相似文献
70.