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排序方式: 共有339条查询结果,搜索用时 343 毫秒
281.
282.
Nakazawa T Kuriu T Tezuka T Umemori H Okabe S Yamamoto T 《Journal of neurochemistry》2008,105(4):1384-1393
The NMDA receptor regulates spine morphological plasticity by modulating Rho GTPases. However, the molecular mechanisms for NMDA receptor-mediated regulation of Rho GTPases remain elusive. In this study, we show that p250GAP, an NMDA receptor-associated RhoGAP, regulates spine morphogenesis by modulating RhoA activity. Knock-down of p250GAP increased spine width and elevated the endogenous RhoA activity in primary hippocampal neurons. The increased spine width by p250GAP knock-down was suppressed by the expression of a dominant-negative form of RhoA. Furthermore, p250GAP is involved in NMDA receptor-mediated RhoA activation. In response to NMDA receptor activation, exogenously expressed green fluorescent protein (GFP)-tagged p250GAP was redistributed. Thus, these data suggest that p250GAP plays an important role in NMDA receptor-mediated regulation of RhoA activity leading to spine morphological plasticity. 相似文献
283.
John L. Woodard Andrew C. Huntsman Pratiq A. Patel Hee-Byung Chai Ragu Kanagasabai Soumendrakrishna Karmahapatra Alexandria N. Young Yulin Ren Malcolm S. Cole Denisse Herrera Jack C. Yalowich A. Douglas Kinghorn Joanna E. Burdette James R. Fuchs 《Bioorganic & medicinal chemistry》2018,26(9):2354-2364
A series of arylnaphthalene lignan lactones based on the structure of the phyllanthusmins, a class of potent natural products possessing diphyllin as the aglycone, has been synthesized and screened for activity against multiple cancer cell lines. SAR exploration was performed on both the carbohydrate and lactone moieties of this structural class. These studies have revealed the importance of functionalization of the carbohydrate hydroxy groups with both acetylated and methylated analogues showing increased potency relative to those with unsubstituted sugar moieties. In addition, the requirement for the presence and position of the C-ring lactone has been demonstrated through reduction and selective re-oxidation of the lactone ring. The most potent compound in this study displayed an IC50 value of 18?nM in an HT-29 assay with several others ranging from 50 to 200?nM. In an effort to elucidate their potential mechanism(s) of action, the DNA topoisomerase IIa inhibitory activity of the most potent compounds was examined based on previous reports of structurally similar compounds, but does not appear to contribute significantly to their antiproliferative effects. 相似文献
284.
285.
Alexandra M. Montoya Mariana Elizondo-Zertuche Rogelio de J. Treviño-Rangel Miguel Becerril-García Gloria M. González 《Revista iberoamericana de micología》2018,35(1):22-26
Background
Trichosporon asahii is a yeast-like fungus that has recently gained importance as a cause of opportunistic systemic infections. The pathogenicity and virulence factors of T. asahii remain largely unknown. Because of the association between invasive infections and the use of catheters and related devices, the ability of the microorganism to adhere and form biofilms may play an important role in the pathogenicity during a trichosporonosis.Aims
The aim of this study is to identify an association between biofilm formation by T. asahii isolates and their genotype and/or clinical source.Methods
The biofilm production of 49 T. asahii strains isolated from Mexican patients was measured using the crystal violet stain method, and a comparison made with different adhesion phase incubation times. Antifungal susceptibility testing was performed using a modified CLSI protocol coupled with the quantification of the viable cells with the XTT reduction method.Results
All the T. asahii isolates assayed were able to produce biofilm in vitro, with an intraspecific variability being observed. Overall, increased biofilm production was found when extending the adhesion phase incubation time from 2 to 4 h. No association could be established between the biofilm-producing phenotype and either the genotype or clinical source. Higher antifungal resistance to amphotericin B and fluconazole was linked to increased biofilm production by T. asahii.Conclusions
All clinical isolates tested were able to produce biofilm. No association could be established between biofilm formation and genotype or clinical source. 相似文献286.
Ricardo Andreotti Siqueira Andre Mario Doi Paulo Petrus de Petrus Crossara Paula Celia Mariko Koga Alexandre Gimenes Marques Fabiane Gomes Nunes Jacyr Pasternak Marines Dalla Valle Martino 《Revista iberoamericana de micología》2018,35(2):83-87
Background
An increased incidence of fungal infections caused by Candida species, especially Candida glabrata and Candida krusei, which are less susceptible to azoles, has been observed. Standardized susceptibility testing is essential for clinical management and for monitoring the epidemiology of resistance.Aims
We evaluated the performance of two different susceptibility testing commercial methods, Vitek 2® and Sensititre YeastOne®, and compared them with the standard broth microdilution method (CLSI).Methods
A total of 80 isolates of several Candida species (Candida albicans, Candida parapsilosis complex, Candida tropicalis, C. glabrata and C. krusei) were selected for this study.Results
We analyzed the categorical agreement (CA) between the methods, stratifying the disagreements. The average CA between the methods was 96.3% for Vitek 2® and 84% for Sensititre YeastOne®. No very major errors were observed. Major errors and minor errors were found for all the isolates tested. With the azoles, both Vitek 2® and Sensititre YeastOne® had good and similar performance levels, except for C. tropicalis and C. krusei (Sensititre YeastOne® showed low CA, 56.2%). With the echinocandins, both methods showed good performance for C. albicans, C. parapsilosis and C. tropicalis. However, we observed important discrepancies for C. krusei with caspofungin: Vitek 2® had 100% CA while Sensititre YeastOne® had only 25%. With amphotericin B, both Vitek 2® and Sensititre YeastOne® had good performance with high CA.Conclusions
Despite the limited isolates tested, we concluded that both methods have good performance and are reliable for antifungal susceptibility testing. However, caspofungin activity against C. krusei and C. glabrata should be interpreted carefully when using Sensititre YeastOne® because we observed a low CA. 相似文献287.
Song Yang Yanping Zhao Yuanrui Tian Yanchun Chen Xianghai Zhao Ying Li Hailong Zhao Xiaotian Chen Lijun Zhu Zhengmei Fang YingShui Yao Zhibing Hu Chong Shen 《生物化学与生物物理学报:疾病的分子基础》2018,1864(3):778-783
The Rho kinases (ROCKs) are recognized as a critical regulator of vascular functions in cardiovascular disorders. It is crucial to illustrate the association of ROCKs genetic variation and hypertension and/or stroke events. Herein we aimed at investigating the association of ROCK1 and ROCK2 with hypertension and stroke in Chinese Han population. Seven tagSNPs at ROCK1 and ROCK2 were genotyped in a community-based case-control study consisting of 2012 hypertension cases and 2210 normotensive controls and 4128 subjects were further followed up. In stroke case-control study, 1471 ischemic stroke (IS) inpatients and 607 hemorrhagic stroke (HS) inpatients were collected, and 2443 age-matched controls were selected from the follow-up population. Risks were estimated as odds ratio (OR) and hazard ratio (HR) by logistic and Cox regression. The community-based case-control study didn't identify any significant tagSNPs associated with hypertension even after adjustment for covariates. The follow-up analysis showed that rs1481280 of ROCK1 significantly associated with incident hypertension (HR = 1.130, P = 0.048) after adjusting for covariates. rs7589629 and rs978906 of ROCK2 were significantly associated with incident IS (HR = 1.373, P = 0.004; HR = 1.284, P = 0.026) respectively. In stroke case-control study, rs288980, rs1481280 and rs7237677 were significantly associated with IS and the adjusted ORs (P values) of additive model were 0.879 (0.010), 0.895 (0.036) and 0.857 (0.002) respectively. Furthermore, rs288980, rs7237677 and rs978906 were significantly associated with HS and the adjusted ORs (P values) of additive model were 0.857 (0.025), 0.848 (0.018) and 0.856 (0.027) respectively. Our findings suggest that ROCK1 and ROCK2 contribute to the genetic susceptibility of hypertension and stroke. 相似文献
288.
Molecular characterization of a novel RhoGAP, RRC-1 of the nematode Caenorhabditis elegans 总被引:1,自引:0,他引:1
Delawary M Nakazawa T Tezuka T Sawa M Iino Y Takenawa T Yamamoto T 《Biochemical and biophysical research communications》2007,357(2):377-382
The GTPase-activating proteins for Rho family GTPases (RhoGAP) transduce diverse intracellular signals by negatively regulating Rho family GTPase-mediated pathways. In this study, we have cloned and characterized a novel RhoGAP for Rac1 and Cdc42, termed RRC-1, from Caenorhabditis elegans. RRC-1 was highly homologous to mammalian p250GAP and promoted GTP hydrolysis of Rac1 and Cdc42 in cells. The rrc-1 mRNA was expressed in all life stages. Using an RRC-1::GFP fusion protein, we found that RRC-1 was localized to the coelomocytes, excretory cell, GLR cells, and uterine-seam cell in adult worms. These data contribute toward understanding the roles of Rho family GTPases in C. elegans. 相似文献
289.
《Endocrinología y nutrición》2014,61(3):147-152
IntroductionTo validate the use of supine position and CT images for assessing abdominal circumference (AC).MethodA prospective study in consecutive patients undergoing scheduled abdominal CT at our center between 17 and 25 September 2012.AC was measured four times:
- 1.Standing.
- 2.While lying on the CT table.
- 3.On CT images with a skin contour line, using OsiriX software.
- 4.On CT images with an ellipse perimeter formula, using RAIM Alma 2010 software.
290.
BACKGROUND: Anaplastic lymphoma kinase (ALK) inhibitor crizotinib has proven to be effective in the treatment of ALK-mutated neuroblastoma, but crizotinib resistance was commonly observed in patients. We aimed to overcome crizotinib resistance by combining with the MEK inhibitor trametinib or low-dose metronomic (LDM) topotecan in preclinical neuroblastoma models. METHODS: We selected a panel of neuroblastoma cell lines carrying various ALK genetic aberrations to assess the therapeutic efficacy on cell proliferation in vitro. Downstream signals of ALK activation, including phosphorylation of ERK1/2, Akt as well as HIF-1α expression were evaluated under normoxic and hypoxic conditions. Tumor growth inhibition was further assessed in NOD/SCID xenograft mouse models. RESULTS: All NBL cell lines responded to crizotinib treatment but at variable ED50 levels, ranging from 0.25 to 5.58 μM. ALK-mutated cell lines SH-SY5Y, KELLY, LAN-5, and CHLA-20 are more sensitive than ALK wild-type cell lines. In addition, we demonstrated that under hypoxic conditions, all NBL cell lines showed marked decrease of ED50s when compared to normoxia except for KELLY cells. Taking into consideration the hypoxia sensitivity to crizotinib, combined treatment with crizotinib and LDM topotecan demonstrated a synergistic effect in ALKF1174L-mutated SH-SY5Y cells. In vivo, single-agent crizotinib showed limited antitumor activity in ALKF1174L-mutated SH-SY5Y and KELLY xenograft models; however, when combined with topotecan, significantly delayed tumor development was achieved in both SH-SY5Y and KELLY tumor models. CONCLUSIONS: Oral metronomic topotecan reversed crizotinib drug resistance in the ALKF1174L-mutated neuroblastoma preclinical model. 相似文献