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排序方式: 共有104条查询结果,搜索用时 15 毫秒
1.
M T Knabb G G Ahumada B E Sobel J E Saffitz 《The journal of histochemistry and cytochemistry》1985,33(8):744-748
A tissue processing procedure was evaluated for fixation of endogenous long-chain acyl carnitine (LCA) to facilitate autoradiographic subcellular localization of this amphiphile. Suspensions of neonatal rat myocytes labeled with exogenous 14C-palmitoyl carnitine retained 85.2% of the radiolabel after tissue processing. Autoradiography demonstrated no significant translocation of radiolabeled LCA from myocytes to unlabeled sheep erythrocytes mixed in equal proportions and processed together. To evaluate endogenous LCA fixation, cultured myocytes were incubated for 3 days with 3H-carnitine. Radioactivity was distributed in LCA, short-chain acyl carnitine, and free carnitine pools in proportion to the physiological concentrations of the metabolites traced. Before tissue processing, LCA contained 4.5% of total radioactivity. After tissue processing, labeled water-soluble components were lost and 88% of the retained radioactivity was in the LCA pool. The enrichment of endogenous LCA radioactivity was attributable to the selective extraction of endogenous short-chain and free carnitine. Nearly 75% of endogenous LCA was preserved. In contrast, 99.5% of both endogenous short-chain and free carnitine were extracted. Thus, endogenous LCA can be selectively preserved, permitting quantitative subcellular localization of this amphiphile with ultrastructural autoradiography. 相似文献
2.
Population genetics and phylogenetics of DNA sequence variation at multiple loci within the Drosophila melanogaster species complex 总被引:14,自引:1,他引:13
Two regions of the genome, a 1-kbp portion of the zeste locus and a 1.1-
kbp portion of the yolk protein 2 locus, were sequenced in six individuals
from each of four species: Drosophila melanogaster, D. simulans, D.
mauritiana, and D. sechellia. The species and strains were the same as
those of a previous study of a 1.9-kbp region of the period locus. No
evidence was found for recent balancing or directional selection or for the
accumulation of selected differences between species. Yolk protein 2 has a
high level of amino acid replacement variation and a low level of
synonymous variation, while zeste has the opposite pattern. This contrast
is consistent with information on gene function and patterns of codon bias.
Polymorphism levels are consistent with a ranking of effective population
sizes, from low to high, in the following order: D. sechellia, D.
melanogaster, D.mauritiana, and D. simulans. The apparent species
relationships are very similar to those suggested by the period locus
study. In particular, D. simulans appears to be a large population that is
still segregating variation that arose before the separation of D.
mauritiana and D. sechellia. It is estimated that the separation of
ancestral D. melanogaster from the other species occurred 2.5-3.4 Mya. The
separations of D. sechellia and D. mauritiana from ancestral D. simulans
appear to have occurred 0.58- 0.86 Mya, with D. mauritiana having diverged
from ancestral D. simulans 0.1 Myr more recently than D. sechellia.
相似文献
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6.
Peter W. Glunz Xiaojun Zhang Yan Zou Indawati Delucca Alexandra H. Nirschl Xuhong Cheng Carolyn A. Weigelt Daniel L. Cheney Anzhi Wei Rushith Anumula Joseph M. Luettgen Alan R. Rendina Mark Harpel Gang Luo Robert Knabb Pancras C. Wong Ruth R. Wexler E. Scott Priestley 《Bioorganic & medicinal chemistry letters》2013,23(18):5244-5248
Aminoisoquinoline and isoquinoline groups have successfully replaced the more basic P1 benzamidine group of an acylsulfonamide factor VIIa inhibitor. Inhibitory activity was optimized by the identification of additional hydrophobic and hydrophilic P′ binding interactions. The molecular details of these interactions were elucidated by X-ray crystallography and molecular modeling. We also show that decreasing the basicity of the P1 group results in improved oral bioavailability in this chemotype. 相似文献
7.
C García-Vielma MI Dávila-Rodríguez F Hernández-Garza RM Cerda-Flores 《Biotechnic & histochemistry》2016,91(2):102-107
We performed a hospital-based, unmatched case-control study to investigate the association between progressive stages of cervical neoplasia and digital analysis of cell proliferation by silver stained nucleolus organizer region associated proteins (AgNORs). We measured cell proliferation levels in the cervical epithelial cells of 10 women with low grade squamous intraepithelial lesions (LG-SIL), eight with high grade squamous intraepithelial lesions (HG-SIL), 11 with cervical cancer (CC) and eight with no cervical lesions (controls) using the AgNORs technique. Cell proliferation was measured by digital image analysis (DIA). DIA revealed increased total areas of AgNORs in HG-SIL and CC compared to LG-SIL and control patients. AgNORs with a kidney or cluster shape exhibited greater areas than those with a spherical or long shape. We propose a cut-off of 118 pixels to differentiate benign (control and LG-SIL) from malignant (HG-SIL and CC) lesions. DIA of AgNORs is a simple and inexpensive method for studying proliferation. The increased total area of AgNORs in malignant lesions provides information regarding cell behavior and may be related to cervical carcinogenesis; however, further validation studies are required to establish its usefulness in cytological analysis. 相似文献
8.
Smallheer JM Alexander RS Wang J Wang S Nakajima S Rossi KA Smallwood A Barbera F Burdick D Luettgen JM Knabb RM Wexler RR Jadhav PK 《Bioorganic & medicinal chemistry letters》2004,14(21):5263-5267
Modifications to the P4 moiety and pyrazole C3 substituent of factor Xa inhibitor SN-429 provided several new compounds, which are 5-10nM inhibitors of factor IXa. An X-ray crystal structure of one example complexed to factor IXa shows that these compounds adopt a similar binding mode to that previously observed with pyrazole inhibitors in the factor Xa active site both with regard to how the inhibitor binds and the position of Tyr99. 相似文献
9.
1-Thio-beta-D-galactofuranosides: synthesis and evaluation as beta-D- galactofuranosidase inhibitors
Marino C; Marino K; Miletti L; Manso Alves MJ; Colli W; de Lederkremer RM 《Glycobiology》1998,8(9):901-904
Beta-D-galactofuranosidase is a good chemotherapeutic target for the design
of inhibitors, since beta-D-galactofuranose is a constituent of important
parasite glycoconjugates but is not present in the host mammals. With this
aim, we have synthesized for the first time alkyl, benzyl and aryl
1-thio-beta-D-galactofuranosides by condensation of
penta-O-benzoyl-alpha,beta-D-galactofuranose with the corresponding thiols,
in the presence of SnCl4as catalyst. The complete chemical and
spectroscopical characterization of these compounds showed that the
reaction was stereoselective. Debenzoylation with sodium methoxide afforded
the beta-S-galactofuranosides in high yield. The thioglycosides were tested
as inhibitors of the beta-D- galactofuranosidase of Penicillium fellutanum,
using for the first time 4-nitrophenyl-beta-D-galactofuranoside as
chromogenic substrate. The 4- aminophenyl-1-thio-beta-D-galactofuranoside,
obtained by catalytic hydrogenation of the nitrophenyl derivative, was the
best inhibitor being then an adequate ligand for the preparation of an
affinity phase aimed at the isolation of beta-d-galactofuranosidases from
different sources. Also the inhibitory activity of d-galactono-1, 4-lactone
was shown.
相似文献
10.
Rebecca Vicente-Steijn Roderick W. C. Scherptong Boudewijn P. T. Kruithof Sjoerd N. Duim Marie Jose T. H. Goumans Lambertus J. Wisse Bin Zhou William T. Pu Robert E. Poelmann Martin J. Schalij Michelle D. Tallquist Adriana C. Gittenberger-de Groot Monique RM Jongbloed 《PloS one》2015,10(9)