Medicine and Health Sciences Commons^™

Common And Distinct Mechanisms Of Different Redox-Active Carcinogens Involved In The Transformation Of Mouse Jb6p+ Cells, Sun Yang, Bobbye J. Misner, Rita Chiu, Frank L. Meyskens Jr.

Pharmacy Faculty Articles and Research

We transformed JB6P+ cells with prolonged intermittent low-dose UVB radiation or prolonged exposure to low-dose H2O2 or CdCl2. Stable transformation was confirmed by an anchorage-independence assay. The JB6P+ transformants formed more colonies (∼six folds) in soft agar as compared to their JB6P+ parent cells and were associated with increased intracellular reactive oxygen species (ROS) levels. Activating protein-1 (AP-1) is a family of transcription factors that are rapidly activated by elevated intracellular ROS levels, and their composition is important in the process of cellular transformation and/or tumor progression. To investigate if carcinogenesis induced by distinct carcinogens was via similar molecular mechanisms …

Uniform Particles Of Pure And Silica Coated Cholesterol, Vuk Uskoković, Egon Matijević

Pharmacy Faculty Articles and Research

Uniform crystalline colloidal cholesterol particles of narrow size distribution were obtained by precipitation. The method consisted of adding a miscible non-solvent (water) into cholesterol solutions of different alcohols and acetone, without any additives. The properties of the resulting particles depended in a sensitive way on the concentration of all reactants, temperature, pH, ionic strength, and aging time. The major observed effects were due to the solubility of cholesterol, which was strongly affected by the solvent mixture and temperature. Precipitation in 1-propanol/water system yielded stable dispersions of well-defined particles, which were used to evaluate the effects of different experimental parameters on …

Phenylalanyl-Trna Synthetase Editing Defects Result In Efficient Mistranslation Of Phenylalanine Codons As Tyrosine, Jiqiang Ling, Srujana S. Yadavalli, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Translational quality control is monitored at several steps, including substrate selection by aminoacyl-tRNA synthetases (aaRSs), and discrimination of aminoacyl-tRNAs by elongation factor Tu (EF-Tu) and the ribosome. Phenylalanyl-tRNA synthetase (PheRS) misactivates Tyr but is able to correct the mistake using a proofreading activity named editing. Previously we found that overproduction of editing-defective PheRS resulted in Tyr incorporation at Phe-encoded positions in vivo , although the misreading efficiency could not be estimated. This raised the question as to whether or not EF-Tu and the ribosome provide further proofreading mechanisms to prevent mistranslation of Phe codons by Tyr. Here we show that, …

An Aminoacyl-Trna Synthetase: Elongation Factor Complex For Substrate Channeling In Archaeal Translation, Corinne D. Hausmann, Mette Praetorius-Ibba, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Translation requires the specific attachment of amino acids to tRNAs by aminoacyl-tRNA synthetases (aaRSs) and the subsequent delivery of aminoacyl-tRNAs to the ribosome by elongation factor 1 alpha (EF-1α). Interactions between EF-1α and various aaRSs have been described in eukaryotes, but the role of these complexes remains unclear. To investigate possible interactions between EF-1α and other cellular components, a yeast two-hybrid screen was performed for the archaeon Methanothermobacter thermautotrophicus. EF-1α was found to form a stable complex with leucyl-tRNA synthetase (LeuRS; KD = 0.7 μ M). Complex formation had little effect on EF-1α activity, but increased the k_{cat …}

Fibrocystin/Polyductin, Found In The Same Protein Complex With Polycystin-2, Regulates Calcium Responses In Kidney Epithelia, Shizuan Wang, Jingjing Zhang, Surya M. Nauli, Xiaogang Li, Patrick G. Starremans, Ying Luo, Kristina A. Roberts, Jing Zhou

Pharmacy Faculty Articles and Research

Recent evidence suggests that fibrocystin/polyductin (FPC), polycystin-1 (PC1), and polycystin-2 (PC2) are all localized at the plasma membrane and the primary cilium, where PC1 and PC2 contribute to fluid How sensation and may function in the same mechanotransduction pathways. To further define the exact subcellular localization of FPC, the protein product encoded by the PKHD1 gene responsible for autosomal recessive polycystic kidney disease (PKD) in humans, and whether FPC has direct and/or indirect cross talk with PC2, which, in turn, is pivotal for the pathogenesis of autosomal dominant PKD, we performed double immunostaining and coimmunoprecipitation as well as a microfluorimetry …

Alcohol-Induced Suppression Of Gluconeogenesis Is Greater In Ethanol Fed Female Rat Hepatocytes Than Males, Ken D. Sumida, Alma A. Cogger, Aleksey V. Matveyenko

Physical Therapy Faculty Articles and Research

The impact of alcohol-induced suppression on hepatic gluconeogenesis (HGN) after chronic ethanol consumption between males and females is unknown. To determine the effects of chronic alcohol consumption (8 weeks) on HGN, the isolated hepatocyte technique was used on 24 h fasted male and female Wistar rats. Livers were initially perfused with collagenase and the hepatocytes were isolated. Aliquots of the cell suspension were placed in Krebs-Henseleit buffer and incubated for 30 min with lactate, [U-C-14]lactate, and nine different concentrations of ethanol (EtOH). Dose-effect curves were generated for the determination of maximal and half-maximal alcohol-induced inhibition on HGN. There was no …

Coupling Coherence Distinguishes Structure Sensitivity In Protein Electron Transfer, Tatiana Prytkova, Igor V. Kurnikov, David Beratan

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quantum mechanical analysis of electron tunneling in nine thermally fluctuating cytochrome b562 derivatives reveals two distinct protein-mediated coupling limits. A structure-insensitive regime arises for redox partners coupled through dynamically averaged multiple-coupling pathways (in seven of the nine derivatives) where heme-edge coupling leads to the multiple-pathway regime. A structure-dependent limit governs redox partners coupled through a dominant pathway (in two of the nine derivatives) where axial-ligand coupling generates the single-pathway limit and slower rates. This two-regime paradigm provides a unified description of electron transfer rates in 26 ruthenium-modified heme and blue-copper proteins, as well as in numerous photosynthetic proteins.

Flavin Charge Transfer Transitions Assist Dna Photolyase Electron Transfer, Spiros S. Skourtis, Tatiana Prytkova, David Beratan

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

This contribution describes molecular dynamics, semi-empirical and ab-initio studies of the primary photo-induced electron transfer reaction in DNA photolyase. DNA photolyases are FADH−-containing proteins that repair UV-damaged DNA by photo-induced electron transfer. A DNA photolyase recognizes and binds to cyclobutatne pyrimidine dimer lesions of DNA. The protein repairs a bound lesion by transferring an electron to the lesion from FADH−, upon photo-excitation of FADH− with 350–450 nm light. We compute the lowest singlet excited states of FADH− in DNA photolyase using INDO/S configuration interaction, time-dependent density-functional, and time-dependent Hartree-Fock methods. The calculations identify the lowest singlet excited state of FADH− …

The Pet Food Recall Puzzle: Who, What, Why, And How Much, Roxanne Greitz Miller

Education Faculty Articles and Research

Last spring, North America was gripped in the largest pet food recall in history. News outlets reported tens of thousands of dogs and cats becoming ill, and many dying, as a result of ingesting contaminated pet food. Several pet owners have filed lawsuits against the manufacturers and distributors of the pet food products. I think this is an excellent real-life science story to use with students to show science investigation in action, and to discuss the intersections between the role of regulatory agencies and the public.

In order to understand the case, you first have to know the facts. We'll …

Making Some Bones About It, Roxanne Greitz Miller, Frank Frisch

Education Faculty Articles and Research

The article discusses the importance of bone tissue to human beings and the ways to help students to understand its functions. The bone tissue forms the human skeleton to produce varied motions such as walking and talking. In addition, it protects the vital organs of a person and contributes the development of blood. The bone is composed of bone matrix, a dense material occupied by calcium and potassium salts. The matrix comprises several cell types including osteoblasts, osteocytes and osteoclasts. According to the author, a continuous influx of new calcium is necessary because of the constant remodeling of bone tissue. …

The Endogenous Cannabinoid Anandamide Inhibits Cromakalim-Activated K+ Currents In Follicle-Enclosed Xenopus Oocytes, Murat Oz, Keun-Hang Susan Yang, Meral Dinc, Toni S. Shippenberg

Mathematics, Physics, and Computer Science Faculty Articles and Research

The effect of the endogenous cannabinoid anandamide on K+ currents activated by the ATP-sensitive potassium (KATP) channel opener cromakalim was investigated in follicle-enclosed Xenopus oocytes using the two-electrode voltage-clamp technique. Anandamide (1–90 μM) reversibly inhibited cromakalim-induced K+ currents, with an IC50 value of 8.1 ± 2 μM. Inhibition was noncompetitive and independent of membrane potential. Coapplication of anandamide with the cannabinoid type 1 (CB1) receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR 141716A) (1 μM), the CB2 receptor antagonist N-[(1S)endo-1,3,3-trimethyl bicyclo heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528) (1 μM), or pertussis toxin (5 μg/ml) did not alter the inhibitory effect of anandamide, suggesting that known cannabinoid receptors …

Four Novel Co-Precipitation Procedures For The Synthesis Of Lanthanum-Strontium Manganites, Vuk Uskoković, Miha Drofenik

Pharmacy Faculty Articles and Research

Lanthanum-strontium manganites were synthesized using co-precipitation method with a reverse micellar microemulsion. Either oxalic acid, sodium hydroxide or tetramethylammonium hydroxide was used for the precipitation of precursor cations in a form that was subsequently calcined under various conditions in order to obtain perovskite manganite phase. Correlations between the properties of the synthesized powder and the calcination conditions have been put forth. The properties of the microemulsion-assisted synthesized material were compared with the samples prepared by following the supposedly similar chemical recombinations in bulk solutions, with an aim to challenge the fact that microemulsions in general have only templating effects on …

Protein Pyrophosphorylation By Inositol Pyrophosphates Is A Posttranslational Event, Rashna Bhandari, Adolfo Saiardi, Yousef Ahmadibeni, Adele M. Snowman, Adam C. Resnick, Troels Z. Kristiansen, Henrik Molina, Akhilesh Pandey, J. Kent Werner Jr., Krishna R. Juluri, Yong Xu, Glenn D. Prestwich, Keykavous Parang, Solomon H. Snyder

Pharmacy Faculty Articles and Research

In a previous study, we showed that the inositol pyrophosphate diphosphoinositol pentakisphosphate (IP(7)) physiologically phosphorylates mammalian and yeast proteins. We now report that this phosphate transfer reflects pyrophosphorylation. Thus, proteins must be prephosphorylated by ATIP to prime them for IP(7) phosphorylation. IP(7) phosphorylates synthetic phosphopeptides but not if their phosphates have been masked by methylation or pyrophosphorylation. Moreover, IP(7) phosphorylated peptides are more acid-labile and more resistant to phosphatases than ATIP phosphorylated peptides, indicating a different type of phosphate bond. Pyrophosphorylation may represent a novel mode of signaling to proteins.

Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang

Pharmacy Faculty Articles and Research

4-Thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 6603 1), and Aspergillus niger (ATCC 16404) (MIC = 4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks P-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by a-substitution. The unprecedented (+/-)-2-tiydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic …

Electromyographic Data Do Not Support A Progressive Recruitment Of Muscle Fibers During Exercise Exhibiting A Vo2 Slow Component, Daniel T. Cannon, Fred W. Kolkhorst, Daniel Cipriani

Physical Therapy Faculty Articles and Research

The origin of the slow component (SC) of oxygen uptake kinetics, presenting during exercise above the ventilatory threshold (VT), remains unclear. Possible physiologic mechanisms include a progressive recruitment of type II muscle fibers. The purpose of this study was to examine alterations in muscle activity through electromyography (EMG) and mean power frequency (MPF) analysis during heavy cycling exercise. Eight trained cyclists (mean±S.E.; age=30±3 years, height=177±4 cm, weight=73.8±6.5 kg, VO2max=4.33±0.28lmin−1) completed transitions from 20 W to a workload equaling 50% of the difference between VT and VO2max. VO2 was monitored using a breath-by-breath measurement system, and EMG data were gathered from …

Influence Of A Functional Knee Brace And Exercise On Lower Extremity Kinematics During Jogging, Brian M. Campbell, Daniel Cipriani, James A. Yaggie

Physical Therapy Faculty Articles and Research

ABSTRACT Context: Functional knee braces (FKB) are used prophylactically and in rehabilitation to aide in the functional stability of the knee joint. Objective: To determine if alterations in sagittal plane lower extremity kinematics remain evident throughout a one hour period in healthy individuals. Design: 2X5 repeated measures design. Setting: Biomechanics Laboratory. Subjects: Twenty subjects (14 male and 6 female, mean age 26.5±7 yrs; height 172.4±13 cm; weight 78.6±9 kg), separated into braced (B) and no brace (NB) groups. Intervention: A one-hour exercise program divided into three 20 minute increments. Main Outcome Measures: Synchronized three-dimensional …

Effects Of Methylprednisolone And Its Liver-Targeted Dextran Prodrug On Ischemia–Reperfusion Injury In A Rat Liver Transplantation Model, Anjaneya Chimalakonda, Reza Mehvar

Pharmacy Faculty Articles and Research

Purpose. To evaluate the effectiveness of a liver-targeted dextran prodrug (DMP) of methylprednisolone ( MP) in cold preservation-warm reperfusion injury associated with liver transplantation.

Methods. The effects of donor pretreatment with single 5 mg/kg doses of MP or DMP on ischemia reperfusion damage to the liver were studied after 8 or 24 h of cold preservation in both isolated perfused rat liver (IPRL) and syngeneic orthotopic rat liver transplantation (OLT) models.

Results. In IPRL studies, donor pretreatment with DMP, and to a lesser degree MP, significantly improved the uptake of hyaluronic acid (HA), a marker of endothelial …