Stephen Barnes

Learn More
The pleomorphic nature of the immature and mature HIV-1 virions has made it difficult to characterize intersubunit interactions using traditional approaches. While the structures of isolated domains are known, the challenge is to identify intersubunit interactions and thereby pack these domains into supramolecular structures. Using high-resolution mass(More)
Monocyte-derived myeloid cells play vital roles in inflammation-related autoimmune/inflammatory diseases and cancers. Here, we report that exosomes can deliver anti-inflammatory agents, such as curcumin, to activated myeloid cells in vivo. This technology provides a means for anti-inflammatory drugs, such as curcumin, to target the inflammatory cells as(More)
The intestinal absorption, biliary excretion and metabolism of genistein, a potent and specific protein tyrosine kinase inhibitor that occurs naturally in soy foods, was examined in anesthetized, adult female rats fitted with indwelling biliary cannulas. 4-14C-Genistein, when infused into the duodenum, was rapidly absorbed from the intestine, taken up by(More)
Human serum albumin (HSA), the most abundant protein in plasma, has been proposed to have an antioxidant role. The main feature responsible for this property is its only thiol, Cys34, which comprises approximately 80% of the total free thiols in plasma and reacts preferentially with reactive oxygen and nitrogen species. Herein, we show that the thiol in HSA(More)
Superoxide dismutase (SOD) catalyzes the nitration of specific tyrosine residues in proteins by peroxynitrite (ONOO-), which may be the damaging gain-of-function resulting from mutations to SOD associated with familial amyotrophic lateral sclerosis (ALS). We found that disassembled neurofilament-L (light subunit) was more susceptible to tyrosine nitration(More)
The effect of isoflavones on the growth of the human breast carcinoma cell lines, MDA-468 (estrogen receptor negative), and MCF-7 and MCF-7-D-40 (estrogen receptor positive), has been examined. Genistein is a potent inhibitor of the growth of each cell line (IC50 values from 6.5 to 12.0 micrograms/ml), whereas biochanin A and daidzein are weaker growth(More)
A HPLC-MS procedure for the rapid, sensitive and specific measurement of the isoflavones, daidzein, dihydrodaidzein, O-desmethylangolensin and genistein, in human plasma has been developed. Synthetic radiolabeled genistein conjugates were used for evaluation of optimum conditions for solid phase extraction. Biochanin A was added to plasma as a recovery(More)
Superoxide (O2-.), nitric oxide (.NO), and their reaction product peroxynitrite (ONOO-) have all been shown to independently exert toxic target molecule reactions. Because these reactive species are often generated in excess during diverse inflammatory and other pathologic circumstances, we assessed the influence of .NO on membrane lipid peroxidation(More)
International variations in cancer rates have been attributed, at least in part, to differences in dietary intake. Recently, it has been suggested that consumption of soyfoods may contribute to the relatively low rates of breast, colon, and prostate cancers in countries such as China and Japan. Soybeans contain a number of anticarcinogens, and a recent(More)
We compared the effects of the tyrosine kinase inhibitor genistein, a naturally occurring isoflavone, to those of tyrphostin A25, tyrphostin A47, and herbimycin on avian osteoclasts in vitro. Inactive analogs daidzein and tyrphostin A1 were used to control for nonspecific effects. None of the tyrosine kinase inhibitors inhibited bone attachment. However,(More)