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排序方式: 共有391条查询结果,搜索用时 115 毫秒
71.
72.
Handzlik J Maciag D Kubacka M Mogilski S Filipek B Stadnicka K Kieć-Kononowicz K 《Bioorganic & medicinal chemistry》2008,16(11):5982-5998
In the search for new antiarrhythmic agents, some active 2-methoxyphenylpiperazine derivatives of phenytoin were obtained as a chemical modification of compound AZ-99 (3-ethyl-1-[2-hydroxy-3-(4-phenylpiperazin-1-yl)-propyl]-2,4-dioxo-5,5-diphenylimidazolidine). These compounds possessed structural properties similar to those of alpha(1)-adrenoceptor antagonists. In the present study, the affinities of the 2-methoxyphenylpiperazine derivatives (1a-3a) for alpha(1)- and alpha(2)-adrenoceptors were evaluated using radioligand ([(3)H]prazosin, [(3)H]clonidine) binding assays. In the next step, a new series of phenylpiperazine derivatives of phenytoin (4a-16a) containing 2-methoxyphenyl-, 2-ethoxyphenyl-, 2-pyridyl- or 2-furoylpiperazine moiety, as well as, various ester or alkyl substituents at 3-position of hydantoin ring were synthesized. The newly synthesized compounds were tested for their affinity to alpha(1)- and alpha(2)-adrenoceptors. They have shown affinities for alpha(1)-adrenoceptors at nanomolar to submicromolar range. Some compounds were moderately selective ligands of alpha(1)-adrenoceptors. Selected compounds (3a-5a, 7a, 13a, 14a) were also evaluated for their alpha(1)-adrenoceptor antagonistic properties in functional bioassays. A SAR study indicated that the most active compounds contain 2-alkoxyphenylpiperazine moieties and methyl or 2-methylpropionate substituent at 3-N position in hydantoin. The exchange of 2-alkoxyphenyl moiety into 2-furoyl or 2-pyridyl group significantly decreased affinities for alpha(1)-adrenoceptors. Molecular modelling results obtained using conformational analysis CONFLEX and PM5 method for geometry optimization, allowed for comparison of the spatial properties of tested compounds with pharmacophore model created by Barbaro et al. for the ideal alpha(1)-adrenoceptor antagonist. 相似文献
73.
74.
Simon Rajendran Slawomir Salwa Xuefeng Gao Sabin Tabirca Deirdre O'Hanlon Gerald C. O'Sullivan Mark Tangney 《Journal of visualized experiments : JoVE》2010,(41)
This video describes the establishment of liver metastases in a mouse model that can be subsequently analysed by bioluminescent imaging. Tumour cells are administered specifically to the liver to induce a localised liver tumour, via mobilisation of the spleen and splitting into two, leaving intact the vascular pedicle for each half of the spleen. Lewis lung carcinoma cells that constitutively express the firefly luciferase gene (luc1) are inoculated into one hemi-spleen which is then resected 10 minutes later. The other hemi-spleen is left intact and returned to the abdomen. Liver tumour growth can be monitored by bioluminescence imaging using the IVIS whole body imaging system. Quantitative imaging of tumour growth using IVIS provides precise quantitation of viable tumour cells. Tumour cell death and necrosis due to drug treatment is indicated early by a reduction in the bioluminescent signal. This mouse model allows for investigating the mechanisms underlying metastatic tumour-cell survival and growth and can be used for the evaluation of therapeutics of liver metastasis. Download video file.(57M, mp4) 相似文献
75.
Domon MM Besson F Bandorowicz-Pikula J Pikula S 《Biochemical and biophysical research communications》2011,405(2):192-196
Niemann-Pick type C (NPC) disease is characterized by excessive accumulation of cholesterol in the late endosome/lysosome compartment. Some members of the annexin family of proteins such as annexin A2 (AnxA2) and annexin A6 (AnxA6) follow the same route as cholesterol during the endocytic pathway and are found, as AnxA6, attached to the membranes of the cholesterol storage compartment in NPC disease fibroblasts. Therefore, the purpose of this work was to test the hypothesis that AnxA6 participates in the NPC-induced changes in the organization of membrane microdomains resistant to solubilization by a nonionic detergent, Triton X-100, i.e., detergent-resistant microdomains (DRMs). Using cellular fractionation, fluorescence microscopy and specific antibodies we observed that in the absence of calcium AnxA6 was found in the DRM-depleted membrane fractions isolated from NPC and control fibroblasts. In the presence of calcium, AnxA6 re-located to the fractions enriched in DRMs only in the NPC cells, suggestive of AnxA6 participation in organization of these microdomains. 相似文献
76.
Kilanczyk E Filipek S Filipek A 《Biochemical and biophysical research communications》2011,404(1):179-183
Recently, we have reported that the CacyBP/SIP protein binds ERK1/2 (Kilanczyk et al., BBRC, 2009). In this work we show that CacyBP/SIP exhibits a phosphatase activity toward ERK1/2 kinases while its E217K mutant does not. The Km and Vmax values established for a standard phosphatase substrate, p-NPP, are 16.9 ± 3.6 mM and 4.3 ± 0.4 μmol/min, respectively. The CacyBP/SIP phosphatase activity is decreased by okadaic acid (IC50 = 45 nM). Our experimental results are supported by a theoretical analysis which revealed important sequence similarities between CacyBP/SIP and the phosphatase-like proteins as well as certain MAP kinase phosphatases. 相似文献
77.
Michalina Kosiorek Paulina Podszywalow-Bartnicka Ludmila Zylinska Krzysztof Zablocki Slawomir Pikula 《Biochemical and biophysical research communications》2011,411(2):89
PMCA1–4 isoforms have been recently recognised as regulators of various signalling pathways in mammalian cells. PMCAs were found to interact with calcineurin A in an isoform specific manner. In this study we focus on the interaction of calcineurin A with PMCA4 and its effect on catecholamine secretion in PC12 cells with reduced PMCA2 or PMCA3 content. Reduction of synthesis of PMCA2 or PMCA3 led to upregulation of PMCA4 manifested by preferential interaction of PMCA4 with calcineurin A. On the other hand, we observed a significant reduction of dopamine secretion, which did not correspond with an increased [Ca2+]c. This result indicates that the interaction of PMCA4 with calcineurin A plays a regulatory role in the signalling during catecholamine secretion. 相似文献
78.
Ajay P. Nayak Françoise M. Blachere Justin M. Hettick Slawomir Lukomski Detlef Schmechel Donald H. Beezhold 《Mycopathologia》2011,171(1):23-34
Fungal hemolysins are potential virulence factors. Some fungal hemolysins belong to the aegerolysin protein family that includes
cytolysins capable of lysing erythrocytes and other cells. Here, we describe a hemolysin from Aspergillus terreus called terrelysin. We used the genome sequence database to identify the terrelysin sequence based on homology with other
known aegerolysins. Aspergillus terreus mRNA was isolated, transcribed to cDNA and the open reading frame for terrelysin amplified by PCR using specific primers.
Using the pASK-IBA6 cloning vector, we produced recombinant terrelysin (rTerrelysin) as a fusion product in Escherichia coli. The recombinant protein was purified and using MALDI-TOF MS determined to have a mass of 16,428 Da. Circular dichroism analysis
suggests the secondary structure of the protein to be predominantly β-sheet. Results from thermal denaturation of rTerrelysin
show that the protein maintained the β-sheet confirmation up to 65°C. Polyclonal antibody to rTerrelysin recognized a protein
of approximately 16.5 kDa in mycelial extracts from A. terreus. 相似文献
79.
Dobrzycka B Terlikowski SJ Garbowicz M Niklinski J Chyczewski L Kulikowski M 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2011,49(4):631-635
The objective of this study was to verify the frequency of P53 and BCL-2 immunohistochemical expression in 98 patients with endometrial carcinoma, and to correlate it with clinical stage and patient survival. A significant difference was found regarding the frequency of P53 expression when comparing type I and II tumors (23.7% and 54.5%, respectively; p = 0.006). A positive correlation was observed between P53 immunoexpression and patient survival in type I and II tumors (p = 0.009 and p = 0.036, respectively). BCL-2 expression was significantly more frequent in early clinical stages in both types of endometrial cancer (p 〈 0.001 and 0.002) and correlated with a decrease in overall survival in type I endometrial cancer (p = 0.014). Thus, the prognostic value of these biomarkers in endometrial cancer needs to be further investigated. 相似文献
80.
Charatsi I Luschnig S Bartoszewski S Nüsslein-Volhard C Moussian B 《Mechanisms of development》2003,120(2):219-226
In Drosophila, the dorsoventral axis is set up by the action of the dorsal group of genes and cactus, which have been ordered genetically in a linear pathway. We have identified and characterised krapfen (kra) as a new member of the dorsal-group genes. kra encodes for the Drosophila homologue of MyD88, an adapter protein operating in the mammalian IL-1 pathway. Epistasis experiments reveal that kra acts between the receptor Toll and the cytoplasmic factor Tube. We show that there is a direct interaction between Kra and Tube presumably mediated by the death domains present in both proteins. Tube in turn interacts with its downstream effector Pelle through death domain association. We therefore suggest that upon Toll activation, Kra associates with Pelle and Tube, in an heterotrimeric complex. 相似文献