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31.
Amiloride does not alter NaCl avoidance in Fischer-344 rats 总被引:2,自引:2,他引:0
Fischer-344 (F-344) rats differ from other common rat strains in that they
fail to show any preference for NaCl at any concentration in two- bottle
preference tests. Because 100 microM amiloride partially blocks the
NaCl-evoked chorda tympani (CT) response in electrophysiological studies,
we tested NaCl preference (0.068-0.273 M) in F-344 rats with and without
100 microM amiloride solution as the solvent. A third group was tested with
unadulterated NaCl solutions following CT transection. Amiloride had no
significant effect on the NaCl preference-aversion function, whereas CT
transection significantly reduced NaCl avoidance. These results suggest
that the amiloride-sensitive component of the NaCl response is not
necessary for F-344 rats to display avoidance of NaCl, but the entire CT
input is.
相似文献
32.
33.
Guilherme L. Pinheiro Jimmy Esneider Rodriguez Gilberto B. Domont Wanderley de Souza Magno Junqueira Susana Frases 《Bioenergy Research》2017,10(1):1-12
Two general strategies have been proposed for microbial cellulose degradation: filamentous fungi and aerobic bacteria secrete uncomplexed cellulases, while some anaerobic bacteria produce a cell-associated and large extracellular multienzymatic complex called cellulosomes. By using a combination of 1D-blue native (BN)-PAGE, 2D-BN/SDS-PAGE, zymography, and LC-MS/MS methods, we demonstrate here that Streptomyces sp. I1.2, an aerobic bacterium associated with the land snail Achatina fulica, is able to degrade both crystalline cellulose and sugarcane bagasse through the production of cellulolytic multienzymatic complexes containing different combinations of cellobiohydrolases, endo-glucanases, xylanases, lytic polysaccharide monooxygenases (LPMOs), and peptidases. The assembly and subunit composition of these complexes is specifically affected by the carbon source, while the multienzymatic complexes produced after growth in crystalline cellulose are composed mainly by one cellobiohydrolase and chitinase, in which the complexes produced in response to sugarcane bagasse are more heterogeneous and contain cellobiohydrolases, endo-glucanases, pectate lyases, one LPMO, β-1,3-glucanases, and one xylanase. Our results suggest that Streptomyces sp. I1.2 displays an alternative mechanism for deconstruction of cellulose that depends upon a noncellulosomic association of catalytic subunits into high molecular weight complexes in order to achieve higher catalytic efficiencies. 相似文献
34.
Inspiratory muscle weakness in patients with COPD is of major clinical relevance. For instance, maximum inspiratory pressure generation is an independent determinant of survival in severe COPD. Traditionally, inspiratory muscle weakness has been ascribed to hyperinflation-induced diaphragm shortening. However, more recently, invasive evaluation of diaphragm contractile function, structure, and biochemistry demonstrated that cellular and molecular alterations occur, of which several can be considered pathologic of nature. Whereas the fiber type shift towards oxidative type I fibers in COPD diaphragm is regarded beneficial, rendering the overloaded diaphragm more resistant to fatigue, the reduction of diaphragm fiber force generation in vitro likely contributes to diaphragm weakness. The reduced diaphragm force generation at single fiber level is associated with loss of myosin content in these fibers. Moreover, the diaphragm in COPD is exposed to oxidative stress and sarcomeric injury. This review postulates that the oxidative stress and sarcomeric injury activate proteolytic machinery, leading to contractile protein wasting and, consequently, loss of force generating capacity of diaphragm fibers in patients with COPD. Interestingly, several of these presumed pathologic alterations are already present early in the course of the disease (GOLD I/II), although these patients appear not limited in their daily life activities. Treatment of diaphragm dysfunction in COPD is complex since its etiology is unclear, but recent findings indicate the ubiquitin-proteasome pathway as a prime target to attenuate diaphragm wasting in COPD. 相似文献
35.
Junqueira M Spirin V Santana Balbuena T Waridel P Surendranath V Kryukov G Adzhubei I Thomas H Sunyaev S Shevchenko A 《Journal of proteome research》2008,7(8):3382-3395
Only a small fraction of spectra acquired in LC-MS/MS runs matches peptides from target proteins upon database searches. The remaining, operationally termed background, spectra originate from a variety of poorly controlled sources and affect the throughput and confidence of database searches. Here, we report an algorithm and its software implementation that rapidly removes background spectra, regardless of their precise origin. The method estimates the dissimilarity distance between screened MS/MS spectra and unannotated spectra from a partially redundant background library compiled from several control and blank runs. Filtering MS/MS queries enhanced the protein identification capacity when searches lacked spectrum to sequence matching specificity. In sequence-similarity searches it reduced by, on average, 30-fold the number of orphan hits, which were not explicitly related to background protein contaminants and required manual validation. Removing high quality background MS/MS spectra, while preserving in the data set the genuine spectra from target proteins, decreased the false positive rate of stringent database searches and improved the identification of low-abundance proteins. 相似文献
36.
Luciane Mendes Hatadani James O. McInerney Hermes Fonseca de Medeiros Ana Carolina Martins Junqueira Ana Maria de Azeredo-Espin Louis Bernard Klaczko 《Molecular phylogenetics and evolution》2009,51(3):595-600
We suggest a new phylogenetic hypothesis for the tripunctata radiation based on sequences of mitochondrial genes. Phylogenetic trees were reconstructed by parsimony, maximum likelihood and Bayesian methods. We performed tests for hypotheses of monophyly for taxonomic groups and other specific hypotheses. Results reject the monophyly for the tripunctata group whereas monophyly is not rejected for the tripunctata radiation and other specific groups within the radiation. Although most of the basal nodes were unresolved we were able to identify four clusters within the tripunctata radiation. These results suggest the collection of additional data before a proper taxonomic revision could be proposed. 相似文献
37.
Li Ding Maciej Paszkowski-Rogacz Anja Nitzsche Mikolaj Michal Slabicki Anne-Kristin Heninger Ingrid de Vries Ralf Kittler Magno Junqueira Andrej Shevchenko Herbert Schulz Norbert Hubner Michael Xavier Doss Agapios Sachinidis Juergen Hescheler Roberto Iacone Konstantinos Anastassiadis A. Francis Stewart M. Teresa Pisabarro Antonio Caldarelli Ina Poser Frank Buchholz 《Cell Stem Cell》2009,4(5):403-415
38.
Impact of moisture on in vitro germination of Metarhizium anisopliae and Beauveria bassiana and their activity on Triatoma infestans 总被引:2,自引:1,他引:1
Gustavo Maximiano Junqueira Lazzarini Luiz Fernando Nunes Rocha Christian Luz 《Mycological Research》2006,110(4):485-492
The in vitro germination of 11 Metarhizium anisopliae and 11 Beauveria bassiana isolates originating from substrates collected in rural peridomestic areas in Central Brazil where triatomines are common was tested. Conidia completed germination up to 24 h after exposure to water activity of >0.99 aw in all isolates tested. At lower 0.93 aw germination was delayed but conidia of most isolates germinated at high rates (>98 %) within 216 h of incubation. Activities of 2 M. anisopliae and 2 B. bassiana isolates with different patterns of germination at 0.93 aw were tested in Triatoma infestans third instar nymphs. There was no relationship between germination kinetics in vitro at 0.93 aw and their activity in vivo at 98, 75 and 43 % relative humidity (rh). Isolates with accelerated germination at 0.93 aw were not more virulent at 75 and 43 % rh compared with isolates with retarded or no germination. Highest mortalities were observed at 98 % rh, and they did not exceed 25 % after 25 d incubation at lower 75 and 43 % rh. Isolates that originated from a region with an extensive annual arid period showed no adaptation to lower humidity in their activity against T. infestans. 相似文献
39.
Barbara L. Ignacio Luciana M. Julio Andrea O. R. Junqueira Maria A. G. Ferreira-Silva 《PloS one》2010,5(9)
Background
Biological invasions are a major cause of global species change. Nevertheless, knowledge about the distribution and ecology of introduced species is regionally biased, and many gaps in knowledge exist for most developing countries.Methodology/Principal Findings
To study the zoobenthos on the hard substratum of the Ilha Grande Bay, a survey was conducted on both natural and artificial substrata at three depths and seven sites. The species recorded were classified as native, cryptogenic or introduced. Multivariate analyses were conducted to assess the prevalence of introduced species in these communities and to compare the distribution of species on natural and artificial substrata of this bay to identify possible discrepancies in habitat use. Of the 61 species, 25 were cryptogenic, 10 were introduced and 26 were native. Similar numbers of introduced species were found on both natural and artificial substrata, though the community composition was significantly different between them. We also compared the species composition of the Ilha Grande Bay survey to other inventories taken around the world. The highest similarities were found between the Ilha Grande Bay inventory and the Atlantic coastal region (Tampa Bay, USA and the Gulf of Mexico), American Samoa and Pearl Harbor (USA) inventories.Conclusions/Significance
This study presents the first published comprehensive list of hard substratum sessile marine invertebrate species in a Brazilian bay. The high percentage of cryptogenic species reveals gaps in both zoological records and information on introduced species for the Brazilian coast. The introduced species successfully colonized different sites in the Ilha Grande Bay, including both natural and artificial substrata. In addition, we find that artificial structures may not be good surrogates for natural rocky shores and may represent an ecological threat. Comparisons with other inventories suggest a history of broad-scale invasion, though more evidence is needed to support this conclusion. 相似文献40.
Secondary Forests on Anthropogenic Soils of the Middle Madeira River: Valuation, Local Knowledge, and Landscape Domestication
in Brazilian Amazonia. Anthropogenic forests and soils are widespread throughout Amazonia and are the product of the landscape domestication process
carried out by Amazonian societies since pre-Colombian times. Areas of Terra Preta de índio (TPI, Amazonian Dark Earths) are recognized by local rural residents and associated with specific forms of use and management
of these soils and associated secondary forests. We used a quantitative approach to investigate how secondary forests on TPI
are recognized and used by local residents along the middle Madeira River, Central Amazonia. Sixty-two residents were interviewed
in three riverside communities and listed the ethnospecies and their uses in secondary forests on TPI and on non-anthropogenic
soils (NAS). Local residents mentioned more ethnospecies on TPI (mean ± standard deviation: 19.5 ± 8.9) than on NAS (17.4 ± 8.5),
and the use value of the environment to the informants (UVia) was higher on TPI (19 ± 5.7) than on NAS (16.2 ± 6.0). Eleven
ethnospecies were classified as anthropogenic soil indicators, among which three intensively used palms are widely recognized
as indicators of anthropogenic areas and two are domesticated to some degree. The intimate and lasting interactions between
humans and TPI have favored the maintenance of secondary forests in these domesticated landscapes with a diverse assemblage
of useful and domesticated species. Rural residents in Amazonia recognize these forests as an important source of food and
other resources. The use, management, and traditional knowledge related to these domesticated landscapes may provide useful
information for the understanding of Amazonian historical ecology and for the design of more efficient biodiversity management
and conservation plans. 相似文献