The clinical benefits of pan-mTOR active-site inhibitors are limited by toxicity and relief of feedback inhibition of receptor expression. To address these limitations, we designed a series of compounds that selectively inhibit mTORC1 and not mTORC2. These 'bi-steric inhibitors' comprise a rapamycin-like core moiety covalently linked to an mTOR active-site inhibitor.
View Article and Find Full Text PDFAssessment of synergistic effects of drug combinations in vitro is a critical part of anticancer drug research. However, the complexities of dosing and analyzing two drugs over the appropriate range of doses have generally led to compromises in experimental design that restrict the quality and robustness of the data. In particular, the use of a single dose response of combined drugs, rather than a full two-way matrix of varying doses, has predominated in higher-throughput studies.
View Article and Find Full Text PDFObjective: Rheumatoid arthritis therapies that are based on inhibition of a single cytokine, e.g., tumor necrosis factor α (TNFα) or interleukin-6 (IL-6), produce clinically meaningful responses in only about half of the treated patients.
View Article and Find Full Text PDFThis protocol describes the nonlinear optical phenomenon known as second-harmonic generation (SHG) and discusses its special attributes for imaging membrane-potential changes in single cells and multicellular preparations. Undifferentiated N1E-115 mouse neuroblastoma cells are used as a model cellular system for membrane electrophysiology. Styryl and naphthylstyryl dyes, also known as hemicyanines, are a class of electrochromic membrane-staining probes that have been used to monitor membrane potential by fluorescence; they also produce SHG images of cell membranes with SHG intensities that are sensitive to voltage.
View Article and Find Full Text PDFJun N-terminal kinase (JNK) is a stress activated serine/threonine protein kinase that phosphorylates numerous cellular protein substrates including the transcription factors c-Jun and ATF2. In this study, we defined the kinetic mechanism for the active form of JNK2alpha2. Double reciprocal plots of initial rates versus concentrations of substrate revealed the sequential nature of the JNK2alpha2 catalyzed ATF2 phosphorylation.
View Article and Find Full Text PDFArticular cartilage undergoes matrix degradation and loss of mechanical properties when stimulated with proinflammatory cytokines such as interleukin-1 (IL-1). Aggrecanases and matrix metalloproteinases (MMPs) are thought to be principal downstream effectors of cytokine-induced matrix catabolism, and aggrecanase- or MMP-selective inhibitors reduce or block matrix destruction in several model systems. The objective of this study was to use metalloproteinase inhibitors to perturb IL-1-induced matrix catabolism in bovine cartilage explants and examine their effects on changes in tissue compression and shear properties.
View Article and Find Full Text PDFBackground: The purpose of this study is to evaluate the efficacy of aortic valve-sparing repair with glutaraldehyde-treated autologous pericardium in congenital valvular pathology.
Methods: Sixty-two patients underwent reparative aortic valve surgery from January 1997 through December 2003. The mean age was 25 +/- 20 years (+/- standard deviation) (range, 10 days to 81 years).