CPT Pharmacometrics Syst Pharmacol
April 2018
A randomized, double-blind clinical trial was conducted to investigate long-term abuse effects of testosterone cypionate (TC). Thirty-one healthy men were randomized into a dose group of 100, 250, or 500 mg/wk and received 14 weekly injections of TC. A pharmacokinetic/pharmacodynamic (PK/PD) model was developed to characterize testosterone concentrations and link exposure to change in luteinizing hormone and spermatogenesis following long-term TC administration.
View Article and Find Full Text PDFBackground: Lithium was the first clinically effective mood stabilizer marketed worldwide. However, the medical literature suggests that lithium may have an indication as a neuroprotective agent.
Methods: This review discusses the pharmacologic activity and potential effectiveness of lithium in the context of Alzheimer disease (AD) and Parkinson's disease (PD), the 2 most prominent neurodegenerative disorders in the United States.
Lifespan extension through pharmacological intervention may provide valuable tools to understanding the mechanisms of aging and could uncover new therapeutic approaches for the treatment of age-related disease. Although the nematode Caenorhabditis elegans is well known as a particularly suitable model for genetic manipulations, it has been recently used in a number of pharmacological studies searching for compounds with anti-aging activity. These compound screens are regularly performed in amphipathic solvents like dimethyl sulfoxide (DMSO), the solvent of choice for high-throughput drug screening experiments performed throughout the world.
View Article and Find Full Text PDFHunter-killer peptides (HKPs) are synthetic peptides that target specific cell types for apoptosis. These studies report functional and structural characteristics of HKP9, an hunter-killer peptide that specifically targets tumor vasculature with a new apoptotic sequence. Vesicle leakage experiments were performed as a model for membrane perturbing activity.
View Article and Find Full Text PDFAlterations in Ca2+ homeostasis and accumulation of misfolded proteins in the endoplasmic reticulum (ER) cause ER stress that ultimately leads to programmed cell death. Recent studies have shown that ER stress triggers programmed cell death via an alternative intrinsic pathway of apoptosis that, unlike the intrinsic pathway described previously, is independent of Apaf-1 and cytochrome c. In the present work, we have used a set of complementary approaches, including two-dimensional gel electrophoresis coupled with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and nano-liquid chromatography-electrospray ionization mass spectrometry with tandem mass spectrometry, RNA interference, co-immunoprecipitation, immunodepletion of candidate proteins, and reconstitution studies, to identify mediators of the ER stress-induced cell death pathway.
View Article and Find Full Text PDFProtein engineering is an emerging area that has expanded our understanding of protein folding and laid the groundwork for the creation of unprecedented structures with unique functions. We previously designed the first native-like pore-forming protein, small globular protein (SGP). We show here that this artificially engineered protein has membrane-disrupting properties and anti-tumor activity in several cancer animal models.
View Article and Find Full Text PDFWe previously reported that the 18-mer amphiphilic alpha-helical peptide, Hel 13-5, consisting of 13 hydrophobic residues and five hydrophilic amino acid residues, can induce neutral liposomes (egg yolk phosphatidylcholine) to adopt long nanotubular structures and that the interaction of specific peptides with specific phospholipid mixtures induces the formation of membrane structures resembling cellular organelles such as the Golgi apparatus. In the present study we focused our attention on the effects of peptide sequence and chain length on the nanotubule formation occurring in mixture systems of Hel 13-5 and various neutral and acidic lipid species by means of turbidity measurements, dynamic light scattering measurements, and electron microscopy. We designed and synthesized two sets of Hel 13-5 related peptides: 1) Five peptides to examine the role of hydrophobic or hydrophilic residues in amphiphilic alpha-helical structures, and 2) Six peptides to examine the role of peptide length, having even number residues from 12 to 24.
View Article and Find Full Text PDFAlterations in Ca(2+) homeostasis and accumulation of unfolded proteins in the endoplasmic reticulum (ER) lead to an ER stress response. Prolonged ER stress may lead to cell death. Glucose-regulated protein (GRP) 78 (Bip) is an ER lumen protein whose expression is induced during ER stress.
View Article and Find Full Text PDFAccumulation of misfolded proteins and alterations in Ca2+ homeostasis in the endoplasmic reticulum (ER) causes ER stress and leads to cell death. However, the signal-transducing events that connect ER stress to cell death pathways are incompletely understood. To discern the pathway by which ER stress-induced cell death proceeds, we performed studies on Apaf-1(-/-) (null) fibroblasts that are known to be relatively resistant to apoptotic insults that induce the intrinsic apoptotic pathway.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2002
Organ specific drug targeting was explored in mice as a possible alternative to surgery to treat prostate diseases. Peptides that specifically recognize the vasculature in the prostate were identified from phage-displayed peptide libraries by selecting for phage capable of homing into the prostate after an i.v.
View Article and Find Full Text PDF