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101.
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Pontes B Viana NB Salgado LT Farina M Moura Neto V Nussenzveig HM 《Biophysical journal》2011,(1):582-52
We perform a detailed investigation of the force × deformation curve in tether extraction from 3T3 cells by optical tweezers. Contrary to conventional wisdom about tethers extracted from cells, we find that actin filaments are present within them, so that a revised theory of tether pulling from cells is called for. We also measure steady and maximum tether force values significantly higher than previously published ones for 3T3 cells. Possible explanations for these differences are investigated. Further experimental support of the theory of force barriers for membrane tube extension is obtained. The potential of studies on tether pulling force × deformation for retrieving information on membrane-cytoskeleton interaction is emphasized. 相似文献
104.
Recent bamboo collections from Brazil, and the study of specimens from several Brazilian herbaria revealed that the species
described as Eremocaulon setosum, subtribe Guaduineae, in fact fits within the Arthrostylidiinae genus Aulonemia, based on floral and anatomical characters. Several characters found in this species, such as paniculate determinate synflorescences,
solitary spikelets, an abaxial marginal green stripe on the foliage leaf blades, absence of stomata on the entire adaxial
side of the leaf blade, and intercostal fibers in the mesophyll are typical features of the subtribe Arthrostylidiinae. The
new combination Aulonemia setosa is here proposed, an epitype is designated, and a broader distributional range of this species is documented. 相似文献
105.
Rodríguez-Díaz J Montava R Viana R Buesa J Pérez-Martínez G Monedero V 《Biotechnology letters》2011,33(6):1169-1175
The efficacy of recombinant Lactococcus lactis as a delivery vehicle for a rotavirus antigen was evaluated in a mouse model. The rotavirus VP8* protein was expressed intracellularly
and extracellularly in L. lactis wild type and in an alr mutant deficient in alanine racemase activity, necessary for the synthesis of the cell-wall component d-alanine. When the mucosal immune response was evaluated by measuring VP8*-specific IgA antibody in faeces, wild-type L. lactis triggered a low IgA synthesis only when the secreting strain was used. In contrast, VP8*-specific IgA was detected in faeces
of both groups of mice orally given the alr mutant expressing extracellular VP8* and intracellular VP8*, which reached levels similar to that obtained with the wild
type secreting strain. However, oral administration of the recombinant strains did not induce serum IgG or IgA responses.
L. lactis cell-wall mutants may therefore provide certain advantages when low-antigenic proteins are expressed intracellularly. However,
the low immune response obtained by using this antigen-bacterial host combination prompts to the use of new strains and vaccination
protocols in order to develop acceptable rotavirus immunization levels. 相似文献
106.
Soon, the genetic basis of most human Mendelian diseases will be solved. The next challenge will be to leverage this information to uncover basic mechanisms of disease and develop new therapies. To understand how this transformation is already beginning to unfold, we focus on the ciliopathies, a class of multi-organ diseases caused by disruption of the primary cilium. Through a convergence of data involving mutant gene discovery, proteomics, and cell biology, more than a dozen phenotypically distinguishable conditions are now united as ciliopathies. Sitting at the interface between simple and complex genetic conditions, these diseases provide clues to the future direction of human genetics. 相似文献
107.
Ferro FE de Sousa Lima VB Soares NR de Sousa Almondes KG Pires LV Cozzolino SM do Nascimento Marreiro D 《Biological trace element research》2011,143(2):787-793
Alterations in antioxidant defense in obese people with metabolic syndrome can contribute to oxidative stress. This study
assessed the relationship between the parameters of metabolic syndrome and the zincemia, activity of superoxide dismutase,
and glutathione peroxidase enzymes in obese women. Seventy-three premenopausal women, aged between 20 and 50 years, were divided
into two groups: case group, composed of obese (n = 37), and control group, composed of no obese (n = 36). Analyses of zinc intake, parameters of metabolic syndrome, plasma, and erythrocyte zinc, and activities of superoxide
dismutase and glutathione peroxidase were carried out. The mean values of body mass index of obese women and control group
were 34.5 ± 3.4 and 21.7 ± 1.9 kg/m2, respectively (p < 0.05). In the study, body mass index, waist circumference, and zinc intake were higher in obese women than control group
(p < 0.05). The plasma zinc and activity of superoxide dismutase did not show significant differences between obese and controls
(p > 0.05). The values of erythrocyte zinc was 36.4 ± 15.0 μg/gHb and 45.4 ± 14.3 μg/gHb and of glutathione peroxidase was 46.4 ± 19.4 U/gHb
and 36.7 ± 13.6 U/gHb in obese women and controls, respectively (p < 0.05). The study shows that there are alterations in biochemical parameters of zinc in obese women, with low zinc concentrations
in erythrocytes. Regression analysis demonstrates that the erythrocyte zinc and activity of superoxide dismutase enzyme is
influenced by components of the metabolic syndrome, and the plasmatic glucose, body mass index, and waist circumference have
a negative correlation with this enzyme. 相似文献
108.
Srivastava RM de Almeida Lima A Viana OS da Costa Silva MJ Catanho MT de Morais JO 《Bioorganic & medicinal chemistry》2003,11(8):1821-1827
The synthesis of six 3-aryl-5-(n-propyl)-4,5dihydro-1,2,4-oxadiazoles 3a-f has been achieved in a facile manner by the reaction of an appropriate arylamidoxime 1a-f with butyraldehyde 2. Oxidation of 3a-f individually using MnO(2) in CH(2)Cl(2) or sodium hypochlorite in THF/H(2)O furnished 1,2,4-oxadiazoles 4a-f in good to excellent yields. Compounds 4a-f were also evaluated against inflammation. Except 4e, all of them reduced inflammation, however, 4c presented better antiinflammatory activity. A preliminary antimicrobial activity tests of 3a-f showed that these compounds possess activity against some microorganisms. In fact, 3c and 3f have been found to be more effective against Staphylococcus aureus, Mycobacterium smegmatis, and Candida albicans. 相似文献
109.