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排序方式: 共有540条查询结果,搜索用时 15 毫秒
81.
Ruben Attali Sharon Aharoni Susan Treves Ori Rokach Michal Becker Cohen Yakov Fellig Rachel Straussberg Talya Dor Muhannad Daana Stella Mitrani-Rosenbaum Yoram Nevo 《PloS one》2013,8(7)
We describe an autosomal recessive heterogeneous congenital myopathy in a large consanguineous family. The disease is characterized by variable severity, progressive course in 3 of 4 patients, myopathic face without ophthalmoplegia and proximal muscle weakness. Absence of cores was noted in all patients. Genome wide linkage analysis revealed a single locus on chromosome 19q13 with Zmax = 3.86 at θ = 0.0 and homozygosity of the polymorphic markers at this locus in patients. Direct sequencing of the main candidate gene within the candidate region, RYR1, was performed. A novel homozygous A to G nucleotide substitution (p.Y3016C) within exon 60 of the RYR1 gene was found in patients. ARMS PCR was used to screen for the mutation in all available family members and in an additional 150 healthy individuals. This procedure confirmed sequence analysis and did not reveal the A to G mutation (p.Y3016C) in 300 chromosomes from healthy individuals. Functional analysis on EBV immortalized cell lines showed no effect of the mutation on RyR1 pharmacological activation or the content of intracellular Ca2+ stores. Western blot analysis demonstrated a significant reduction of the RyR1 protein in the patient’s muscle concomitant with a reduction of the DHPRα1.1 protein. This novel mutation resulting in RyR1 protein decrease causes heterogeneous clinical presentation, including slow progression course and absence of centrally localized cores on muscle biopsy. We suggest that RYR1 related myopathy should be considered in a wide variety of clinical and pathological presentation in childhood myopathies. 相似文献
82.
Carl W. White Dee-dee H. Nguyen Keiichiro Suzuki Naoyuki Taniguchi Lee S. Rusakow Karen B. Avraham Yoram Groner 《Free radical biology & medicine》1993,15(6):629-636
In evaluating the relative expression of copper-zinc and manganese superoxide dismutase (CuZnSOD and MnSOD) in vivo in states like Down syndrome in which one dismutase is present at increased levels, we measured activities of both enzymes, in tissues of control and transgenic mice constitutively expressing increased levels of CuZnSOD, during exposure to normal and elevated oxygen tensions. Using SOD gel electrophoresis assay, CuZnSOD and MnSOD activities of brain, lung, heart, kidney, and liver from mice exposed to either normal (21%) or elevated (>99% oxygen, 630 torr) oxygen tensions for 120 h were compared. Whereas CuZnSOD activity was elevated in tissues of transgenic relative to control mice under both normoxic or hyperoxic conditions, MnSOD activities in organs of transgenic mice were remarkably similar to those of controls under both conditions. To confirm the accuracy of this method in quantitating MnSOD relative to CuZnSOD expression, two other methods were utilized. In lung, which is the organ exposed to the highest oxygen tension during ambient hyperoxia, a sensitive, specific ELISA for MnSOD was used. Again, MnSOD protein was not different in transgenic relative to control mice during exposure to air or hyperoxia. In addition, lung MnSOD protein was not changed significantly by exposure to hyperoxia in either group. In kidney, a mitochondrion-rich organ, SOD assay, before and after inactivation of CuZnSOD with diethyldithiocarbamate, was used. MnSOD activity was not different in organs from air-exposed transgenic relative to control mice. The data indicated that expression of MnSOD in vivo was not affected by overexpression of the CuZnSOD and, therefore, the two enzymes are probably regulated independently. 相似文献
83.
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85.
Noam Leader Jonathan Wright† & Yoram Yom-Tov 《Ethology : formerly Zeitschrift fur Tierpsychologie》2002,108(4):367-376
Male orange-tufted sunbirds ( Nectarinia osea ) exhibit distinct song dialects throughout Israel. Recently, two distinct local dialects with a sharp boundary were discovered in a small (1.5 km2 ) urban neighborhood densely inhabited by 63 territorial sunbird pairs. We conducted playback experiments to determine song dialect discrimination capability by sunbird males in this neighborhood. Males of both dialects responded significantly more strongly to playback of their own dialect than to that of the adjacent dialect. In spite of the extreme proximity between the two dialect areas, we found no effect of distance to the neighboring dialect on the intensity of any the behavioral responses. We suggest that due to the complex acoustic properties of this urban neighborhood, sunbirds are extremely limited in the number of neighboring males they can assess to establish what the local song is. A stronger response to one's own dialect is therefore expected, and we discuss how local dialects could be maintained via this mechanism regardless of the very small distances between territories and dialect populations. 相似文献
86.
The preparation of polygalacturonic acid [14C]-labeled methyl ester (pectic acid ester) is described. This labeled polysaccharide is employed as the substrate in a simple, sensitive, and rapid assay procedure for measuring pectin methyl esterase activity. 相似文献
87.
Ethylene has a stabilizing effect on the enzymatic activityof yeast alcohol dehydrogenase solutions. The effects of variousconcentrations of ethylene on enzyme activity are demonstrated. (Received August 8, 1972; ) 相似文献
88.
Prevalence of CagA, VacA Antibodies in Symptomatic and Asymptomatic Children with Helicobacter pylori Infection 总被引:12,自引:0,他引:12
Yoram Elitsur Cheryl Neace Matthew C. Werthammer and William E. Triest 《Helicobacter》1999,4(2):100-105
Background. Limited data are available on the prevalence of CagA and VacA Helicobacter pylori antibodies in children. The aim of this study was to investigate the antibody prevalence to the H. pylori virulence factors CagA and VacA in symptomatic and asymptomatic children with H. pylori infection and to correlate these antibodies with the severity of gastric inflammation or density of H. pylori organisms in the gastric mucosa.
Materials and Methods. Twenty-three symptomatic children and 132 asymptomatic children with positive H. pylori serology participated in this study. Anti– H. pylori IgG antibody and CagA or VacA H. pylori antibodies were measured by enzyme immunoassay (HM-CAP; sensitivity and specificity> 90%) and Western immunoblot (Helicoblot 2.0) methods, respectively. Gastric inflammation and H. pylori density were graded histologically using the revised Sydney criteria.
Results. The prevalence of CagA and VacA antibodies were 69% and 35% in symptomatic children and 54% and 52% in asymptomatic children, respectively. Multiple regression analysis showed a correlation between CagA antibody and the severity of gastritis but no correlation with other histological features, including the number of neutrophils or lymphoid follicles. Neither antibody correlated with the degree of bacterial density in the gastric mucosa.
Conclusion. CagA and VacA H. pylori antibodies are common in the pediatric population. The combined CagA/VacA antibodies correlated weakly with the degree of mucosal inflammation. 相似文献
Materials and Methods. Twenty-three symptomatic children and 132 asymptomatic children with positive H. pylori serology participated in this study. Anti– H. pylori IgG antibody and CagA or VacA H. pylori antibodies were measured by enzyme immunoassay (HM-CAP; sensitivity and specificity> 90%) and Western immunoblot (Helicoblot 2.0) methods, respectively. Gastric inflammation and H. pylori density were graded histologically using the revised Sydney criteria.
Results. The prevalence of CagA and VacA antibodies were 69% and 35% in symptomatic children and 54% and 52% in asymptomatic children, respectively. Multiple regression analysis showed a correlation between CagA antibody and the severity of gastritis but no correlation with other histological features, including the number of neutrophils or lymphoid follicles. Neither antibody correlated with the degree of bacterial density in the gastric mucosa.
Conclusion. CagA and VacA H. pylori antibodies are common in the pediatric population. The combined CagA/VacA antibodies correlated weakly with the degree of mucosal inflammation. 相似文献
89.
Association of Rab25 and Rab11a with the Apical Recycling System of Polarized Madin–Darby Canine Kidney Cells
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James E. Casanova Xiaoye Wang Ravindra Kumar Sheela G. Bhartur Jennifer Navarre Julie E. Woodrum Yoram Altschuler Greg S. Ray James R. Goldenring 《Molecular biology of the cell》1999,10(1):47-61
Recent evidence suggests that apical and basolateral endocytic pathways in epithelia converge in an apically located, pericentriolar endosomal compartment termed the apical recycling endosome. In this compartment, apically and basolaterally internalized membrane constituents are thought to be sorted for recycling back to their site of origin or for transcytosis to the opposite plasma membrane domain. We report here that in the epithelial cell line Madin–Darby Canine Kidney (MDCK), antibodies to Rab11a label an apical pericentriolar endosomal compartment that is dependent on intact microtubules for its integrity. Furthermore, this compartment is accessible to a membrane-bound marker (dimeric immunoglobulin A [IgA]) internalized from either the apical or basolateral pole, functionally defining it as the apical recycling endosome. We have also examined the role of a closely related epithelial-specific Rab, Rab25, in the regulation of membrane recycling and transcytosis in MDCK cells. When cDNA encoding Rab25 was transfected into MDCK cells, the protein colocalized with Rab11a in subapical vesicles. Rab25 transfection also altered the distribution of Rab11a, causing the coalescence of immunoreactivity into multiple denser vesicular structures not associated with the centrosome. Nevertheless, nocodazole still dispersed these vesicles, and dimeric IgA internalized from either the apical or basolateral membrane was detected in endosomes labeled with antibodies to both Rab11a and Rab25. Overexpression of Rab25 decreased the rate of IgA transcytosis and of apical, but not basolateral, recycling of internalized ligand. Conversely, expression of the dominant-negative Rab25T26N did not alter either apical recycling or transcytosis. These results indicate that both Rab11a and Rab25 associate with the apical recycling system of epithelial cells and suggest that Rab25 may selectively regulate the apical recycling and/or transcytotic pathways. 相似文献
90.
Surface charge of nanoparticles determines their endocytic and transcytotic pathway in polarized MDCK cells 总被引:2,自引:0,他引:2
A major challenge in drug delivery is the internalization through the apical plasma membrane of the polarized epithelial cells lining organs facing the external environment, e.g., lungs and the gastrointestinal tract. The reduced permeation of drugs entering through this pathway is in part due to the mucosal barrier and low rate of endocytosis at these membranes. We investigated the possible role of nanoparticle surface charge on its entry through the apical plasma membrane and its intracellular pathway. We found that both cationic and anionic nanoparticles are targeted mainly to the clathrin endocytic machinery. A fraction of both nanoparticle formulations is suspected to internalize through a macropinocytosis-dependent pathway. A significant amount of nanoparticles transcytose and accumulate at the basolateral membrane. Some anionic but not cationic nanoparticles transited through the degradative lysosomal pathway. Taken together, these observations indicate that cationic nanoparticles, in addition to their potential for drug delivery to epithelia, may be promising carriers for transcytosing drugs to the blood stream. 相似文献