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81.
Torregrosa-Hetland CJ Villanueva J López-Font I Garcia-Martinez V Gil A Gonzalez-Vélez V Segura J Viniegra S Gutiérrez LM 《Cellular and molecular neurobiology》2010,30(8):1315-1319
In chromaffin cells, SNARE proteins, forming the basic exocytotic machinery are present in membrane clusters of 500–600 nm
in diameter. These microdomains containing both SNAP-25 and syntaxin-1 are dynamic and the expression of altered forms of
SNAREs modifies not only their motion but also the mobility of the associated granules. It is also clear that SNARE microdomain
location defines the place for individual vesicle fusion and that the alteration of cluster dynamics affects the fusion process
itself. Interestingly, these SNARE patches colocalize with the borders of F-actin cages forming the cytoskeletal cortical
network, and these borders also contain clusters of L- and P/Q type calcium channels. The organization of the secretory machinery
in association with the borders of cytoskeletal cages seems to be an effective way to promote fast coupling between calcium
entry and catecholamine release as demonstrated with the use of mathematical secretory models. 相似文献
82.
Félix Hernández Elena Langa Raquel Cuadros Jesús Avila Nieves Villanueva 《Molecular and cellular biochemistry》2010,344(1-2):211-215
Dephosphorylation of phospho GSK3 isoforms, from COS-7 cells, was determined in vitro and in cultured cells in the absence or the presence of okadaic acid and lithium. Our results indicate a preferential dephosphorylation of phospho GSK3α by PP2A phosphatase, whereas dephosphorylation of phospho GSK3β mainly takes place by PP1 phosphatase. 相似文献
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This study aimed to elucidate the role of charge in mediating chondrocyte response to loading by employing synthetic 3D hydrogels. Specifically, neutral poly(ethylene glycol) (PEG) hydrogels were employed where negatively charged chondroitin sulfate (ChS), one of the main extracellular matrix components of cartilage, was systematically incorporated into the PEG network at 0%, 20% or 40% to control the fixed charge density. PEG hydrogels were employed as a control environment for extracellular events which occur as a result of loading, but which are not associated with a charged matrix (e.g., cell deformation and fluid flow). Freshly isolated bovine articular chondrocytes were embedded in the hydrogels and subject to dynamic mechanical stimulation (0.3 Hz, 15% amplitude strains, 6 h) and assayed for nitric oxide production, cell proliferation, proteoglycan synthesis, and collagen deposition. In the absence of loading, incorporation of charge inhibited cell proliferation by ~ 75%, proteoglycan synthesis by ~ 22–50% depending on ChS content, but had no affect on collagen deposition. Dynamic loading had no effect on cellular responses in PEG hydrogels. However, dynamically loading 20% ChS gels inhibited nitrite production by 50%, cell proliferation by 40%, but stimulated proteoglycan and collagen deposition by 162% and 565%, respectively. Dynamic loading of 40% ChS hydrogels stimulated nitrite production by 62% and proteoglycan synthesis by 123%, but inhibited cell proliferation by 54% and collagen deposition by 52%. Upon removing the load and culturing under free-swelling conditions for 36 h, the enhanced matrix synthesis observed in the 20% ChS gels was not maintained suggesting that loading is necessary to stimulate matrix production. In conclusion, extracellular events associated with a charged matrix have a dramatic affect on how chondrocytes respond to mechanical stimulation within these artificial 3D matrices suggesting that streaming potentials and/or dynamic changes in osmolarity may be important regulators of chondrocytes while cell deformation and fluid flow appear to have less of an effect. 相似文献
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87.
Abiotic influences on embryo growth: statoliths as experimental tools in the squid early life history 总被引:1,自引:0,他引:1
Roger Villanueva Natalie A. Moltschaniwskyj Anna Bozzano 《Reviews in Fish Biology and Fisheries》2007,17(2-3):101-110
Statolith size and growth was used to determine the influence of abiotic factors on the growth of Loligo vulgaris and Sepioteuthis australis embryos. Recently spawned egg masses collected from the field were incubated in the laboratory under different levels of
light intensity, photoperiod, or short periods of low salinity (30‰). Double tetracycline staining was used to follow statolith
growth. In L. vulgaris constant light conditions produced significantly slower growth in the embryonic statoliths and embryos held at summer photoperiod
had slower statolith growth than those held at winter photoperiods. However once they hatched out there was no evidence that
photoperiod affected statolith growth. After hatching, in all photoperiods statolith growth rates decreased in comparison
with late embryonic rates. In S. australis embryos, differences between the high and medium light intensities for summer and intermediate photoperiods were found, suggesting
that under summer incubation temperature, longer daylengths at medium light intensity favoured higher statolith growth for
this species. In comparison to controls, slower statolith growth in S. australis embryos due to low salinity only occurred when exposed for 72 h. Comparison with previous studies indicates that temperature
seems to be the main abiotic factor influencing statolith growth during early stages, however, interactions among all abiotic
factors needs to be determined as well as the unknown influence of other isolated factors, e.g., oxygen concentration within
the egg mass. 相似文献
88.
N. A. Moltschaniwskyj K. Hall Marek R. Lipinski J. E. A. R. Marian M. Nishiguchi M. Sakai D. J. Shulman B. Sinclair D. L. Sinn M. Staudinger R. Van Gelderen R. Villanueva K. Warnke 《Reviews in Fish Biology and Fisheries》2007,17(2-3):455-476
When using cephalopods as experimental animals, a number of factors, including morality, quality of information derived from
experiments, and public perception, drives the motivation to consider welfare issues. Refinement of methods and techniques
is a major step in ensuring protection of cephalopod welfare in both laboratory and field studies. To this end, existing literature
that provides details of methods used in the collection, handling, maintenance, and culture of a range of cephalopods is a
useful starting point when refining and justifying decisions about animal welfare. This review collates recent literature
in which authors have used cephalopods as experimental animals, revealing the extent of use and diversity of cephalopod species
and techniques. It also highlights several major issues when considering cephalopod welfare; how little is known about disease
in cephalopods and its relationship to senescence and also how to define objective endpoints when animals are stressed or
dying as a result of the experiment. 相似文献
89.
90.
Pedroche NB Villanueva LM De Dirk W 《Communications in agricultural and applied biological sciences》2007,72(3):659-666
The root-knot nematode, Meloidogyne incognito (Kofoid et White) Chitwood is an important pathogen of vegetables. Five commercial cultivars of lettuce (Lactuca sativa L.) were evaluated under greenhouse conditions for resistance to Meloidogyne incognita, Benguet population. Plants were inoculated with 1000 eggs collected from 'Apollo' tomato (Lycopersicon esculentum) roots. The degree of galling and number of egg masses were assessed 4 and 8 weeks after inoculation. Host plant response was classified as immune, highly resistant, resistant, moderately resistant, intermediate, moderately susceptible, and highly susceptible based on the resistance index of Kouamè et at., 1998 [RI = (gall2 + egg2)]. Inoculation of 1000 eggs/plant significantly affected the growth and yield of the five lettuce cultivars 4 and 8 weeks after inoculation. A significant interaction was observed between treatment and cultivar during the two evaluation periods in terms of marketable and non-marketable yield, plant height, root weight, number of galls and number of egg masses. A reduction in growth and yield was observed in the cultivars Ballon, Lollo Rosa and Red Wave. Significant differences were noted in the number of galls and egg masses among the different cultivars tested. The highest average number of galls was obtained from the cultivars Red Wave, Ballon and Lollo Rosa. Cultivar Ballon had the highest average number of recovered nematode while Gilaben had the lowest with 15 and 4 per roots, respectively after 4 weeks inoculation. After 8 weeks, nematode was highest in cultivar Red Wave (615) and lowest in Great Lakes (70). Based on the host response, cultivars Great Lakes and Gilaben were rated highly resistant and resistant, respectively, while Red Wave, Ballon and Lollo Rosa were rated intermediate. 相似文献