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排序方式: 共有249条查询结果,搜索用时 31 毫秒
11.
Burdick DJ Marsters JC Aliagas-Martin I Stanley M Beresini M Clark K McDowell RS Gadek TR 《Bioorganic & medicinal chemistry letters》2004,14(9):2055-2059
o-Bromobenzoyl l-tryptophan 1 inhibits the association of LFA-1 with ICAM-1 with an IC(50) of 1.7microM. Evaluation of the structure-activity relationship of the benzoyl moiety shows that 2,6-di-substitutions greatly enhance potency of this class of inhibitors. Electronegative substitutions that favor a 90 degrees angle between the benzoyl ring and the amide bond yield the most potent compounds. There is a strong correlation between the potency of the compounds and the difference between the ab initio energy at 90 degrees and the global minima energy for given compounds. Combining the favored benzoyl substitutions with l-histidine and l-asparagine resulted in a 15-fold increase in potency over compound 1. 相似文献
12.
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
13.
Lai CM Yu MJ Brankov M Barnett NL Zhou X Redmond TM Narfstrom K Rakoczy PE 《Genetic vaccines and therapy》2004,2(1):3
Background
Leber's congenital amaurosis (LCA) is a severe form of retinal dystrophy. Mutations in the RPE65 gene, which is abundantly expressed in retinal pigment epithelial (RPE) cells, account for approximately 10–15% of LCA cases. In this study we used the high turnover, and rapid breeding and maturation time of the Rpe65 -/- knockout mice to assess the efficacy of using rAAV-mediated gene therapy to replace the disrupted RPE65 gene. The potential for rAAV-mediated gene treatment of LCA was then analyzed by determining the pattern of RPE65 expression, the physiological and histological effects that it produced, and any improvement in visual function. 相似文献14.
Stinchcombe JR Rutter MT Burdick DS Tiffin P Rausher MD Mauricio R 《The American naturalist》2002,160(4):511-523
Measuring natural selection has been a fundamental goal of evolutionary biology for more than a century, and techniques developed in the last 20 yr have provided relatively simple means for biologists to do so. Many of these techniques, however, share a common limitation: when applied to phenotypic data, environmentally induced covariances between traits and fitness can lead to biased estimates of selection and misleading predictions about evolutionary change. Utilizing estimates of breeding values instead of phenotypic data with these methods can eliminate environmentally induced bias, although this approach is more difficult to implement. Despite this potential limitation to phenotypic methods and the availability of a potential solution, little empirical evidence exists on the extent of environmentally induced bias in phenotypic estimates of selection. In this article, we present a method for detecting bias in phenotypic estimates of selection and demonstrate its use with three independent data sets. Nearly 25% of the phenotypic selection gradients estimated from our data are biased by environmental covariances. We find that bias caused by environmental covariances appears mainly to affect quantitative estimates of the strength of selection based on phenotypic data and that the magnitude of these biases is large. As our estimates of selection are based on data from spatially replicated field experiments, we suggest that our findings on the prevalence of bias caused by environmental covariances are likely to be conservative. 相似文献
15.
Burdick DJ Paris K Weese K Stanley M Beresini M Clark K McDowell RS Marsters JC Gadek TR 《Bioorganic & medicinal chemistry letters》2003,13(6):1015-1018
The association of ICAM-1 with LFA-1 plays a critical role in several autoimmune diseases. N-2-Bromobenzoyl L-tryptophan, compound 1, was identified as an inhibitor to the formation of the LFA-1/ICAM complex. The SAR of the amino acid indicates that the carboxylic acid is required for inhibition and that L-histidine is the most favored amino acid. 相似文献
16.
Macrophage infiltration in human non-small-cell lung cancer: the role of CC chemokines 总被引:8,自引:0,他引:8
Arenberg DA Keane MP DiGiovine B Kunkel SL Strom SR Burdick MD Iannettoni MD Strieter RM 《Cancer immunology, immunotherapy : CII》2000,49(2):63-70
Bronchogenic carcinoma is the leading cause of malignancy-related mortality in the United States, with an overall 5-year
survival rate of less than 15%. This aggressive behavior reflects, among other traits, the capacity of the tumor to evade
normal host immune defenses, and to induce a pro-angiogenic environment. A central feature of any immune response toward tumors
is the recruitment of specific immune cell populations. In the present study we investigated the infiltration of monocytes
in human specimens of non-small-cell lung cancer (NSCLC). The presence of macrophages in NSCLC tumors was documented by immunohistochemistry.
In vitro chemotaxis assays demonstrated higher monocyte chemotactic activity in NSCLC tumor homogenates than in normal lung
tissue. We next investigated the expression of CC chemokines within specimens of NSCLC tumors. Levels of the CC chemokines
were higher in NSCLC tumor tissue than in normal lung tissue. Immunolocalization showed that the cells associated with antigenic
CC chemokines were the malignant tumor cells, as well as occasional stromal cells. Maximal inhibition of monocyte chemotaxis
induced by NSCLC in vitro occurred in the presence of neutralizing antibodies to MCP-1 and MIP-1β. On follow-up of 15 patients
in whom we quantified macrophage infiltration, we found that those with recurrence of disease had higher levels of macrophage
infiltration in their initial tumors. However, the functional significance of CC-chemokine-mediated macrophage infiltration
into NSCLC remains to be determined.
Received: 12 November 1999 / Accepted: 10 December 1999 相似文献
17.
18.
The reproducible pattern of organismal growth during metazoan development is the product of genetically controlled signaling pathways. Patterned activation of these pathways shapes developing organs and dictates overall organismal shape and size. Here, we show that patches of tissue that are mutant for the Drosophila Tsg101 ortholog, erupted, cause dramatic overproliferation of adjacent wild-type tissue. Tsg101 proteins function in endosomal sorting and are required to incorporate late endosomes into multivesicular bodies. Drosophila cells with impaired Tsg101 function show accumulation of the Notch receptor in intracellular compartments marked by the endosomal protein Hrs. This causes increased Notch-mediated signaling and ectopic expression of the Notch target gene unpaired (upd), which encodes the secreted ligand of the JAK-STAT pathway. Activation of JAK-STAT signaling in surrounding wild-type cells correlates with their overgrowth. These findings define a pathway by which changes in endocytic trafficking can regulate tissue growth in a non-cell-autonomous manner. 相似文献
19.
Sue RD Belperio JA Burdick MD Murray LA Xue YY Dy MC Kwon JJ Keane MP Strieter RM 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(6):3860-3868
Hyperoxia-induced lung injury is characterized by infiltration of activated neutrophils in conjunction with endothelial and epithelial cell injury, followed by fibrogenesis. Specific mechanisms recruiting neutrophils to the lung during hyperoxia-induced lung injury have not been fully elucidated. Because CXCL1 and CXCL2/3, acting through CXCR2, are potent neutrophil chemoattractants, we investigated their role in mediating hyperoxia-induced lung injury. Under variable concentrations of oxygen, murine survival during hyperoxia-induced lung injury was dose dependent. Eighty percent oxygen was associated with 50% mortality at 6 days, while greater oxygen concentrations were more lethal. Using 80% oxygen, we found that lungs harvested at day 6 demonstrated markedly increased neutrophil sequestration and lung injury. Expression of CXCR2 ligands paralleled neutrophil recruitment to the lung and CXCR2 mRNA expression. Inhibition of CXC chemokine ligands/CXCR2 interaction using CXCR2(-/-) mice exposed to hyperoxia significantly reduced neutrophil sequestration and lung injury, and led to a significant survival advantage as compared with CXCR2(+/+) mice. These findings demonstrate that CXC chemokine ligand/CXCR2 biological axis is critical during the pathogenesis of hyperoxia-induced lung injury. 相似文献
20.
Depletion of CXCR2 inhibits tumor growth and angiogenesis in a murine model of lung cancer 总被引:12,自引:0,他引:12
Keane MP Belperio JA Xue YY Burdick MD Strieter RM 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(5):2853-2860
The Glu-Leu-Arg(+) (ELR(+)) CXC chemokines are potent promoters of angiogenesis and have been demonstrated to induce a significant portion of nonsmall cell lung cancer-derived angiogenic activity and support tumorigenesis. ELR(+) CXC chemokines share a common chemokine receptor, CXCR2. We hypothesized that CXCR2 mediates the proangiogenic effects of ELR(+) CXC chemokines during tumorigenesis. To test this postulate, we used syngeneic murine Lewis lung cancer (LLC; 3LL, H-2(b)) heterotopic and orthotopic tumor model systems in C57BL/6 mice replete (CXCR2(+/+)) and deficient in CXCR2 (CXCR2(-/-)). We first demonstrated a correlation of the expression of endogenous ELR(+) CXC chemokines with tumor growth and metastatic potential of LLC tumors. Next, we found that LLC primary tumors were significantly reduced in growth in CXCR2(-/-) mice. Moreover, we found a marked reduction in the spontaneous metastases of heterotopic tumors to the lungs of CXCR2(-/-) mice. Morphometric analysis of the primary tumors in CXCR2(-/-) mice demonstrated increased necrosis and reduced vascular density. These findings were further confirmed in CXCR2(+/+) mice using specific neutralizing Abs to CXCR2. The results of these studies support the notion that CXCR2 mediates the angiogenic activity of ELR(+) CXC chemokines in a preclinical model of lung cancer. 相似文献