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Chemicals and Drugs

2007

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Articles 1 - 30 of 54

Full-Text Articles in Medicine and Health Sciences

Acetylation In Nuclear Receptor Signaling And The Role Of Sirtuins, Chenguang Wang, Michael J. Powell, Vladimir M. Popov, Richard G. Pestell Dec 2007

Acetylation In Nuclear Receptor Signaling And The Role Of Sirtuins, Chenguang Wang, Michael J. Powell, Vladimir M. Popov, Richard G. Pestell

Department of Cancer Biology Faculty Papers

It has been known since the early 1970s that nuclear receptor complexes bind DNA in association with co-regulatory proteins. Characterization of these nuclear receptor coregulators has revealed diverse enzymatic activities which temporally and spatially coordinate nuclear receptor activity within the context of local chromatin in response to diverse hormone signals. Chromatin modifying proteins, which dictate the higher order chromatin structure in which DNA is packaged, in turn orchestrate orderly recruitment of nuclear receptor complexes. Modifications of histones include acetylation, methylation, phosphorylation, ubiquitylation, sumoylation, ADP ribosylation, deimination and proline isomerization (1). At this time, we understand how a subset of these …


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. Dec 2007

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 …


Localization Of A Microsporidia Adam (A Disintegrin And Metalloprotease Domain) Protein And Identification Of Potential Binding Partners., Carrie E. Jolly Dec 2007

Localization Of A Microsporidia Adam (A Disintegrin And Metalloprotease Domain) Protein And Identification Of Potential Binding Partners., Carrie E. Jolly

Electronic Theses and Dissertations

Microsporidia are spore-forming, obligate intracellular pathogens typically associated with opportunistic infections in immunocompromised individuals. Treatment options for microsporidia infections in humans are limited and additional research is necessary to create better therapeutic agents. For many pathogenic organisms, adhesion to the host cell surface is a prerequisite for tissue colonization and invasion. Our previous research has demonstrated a direct relationship between adherence of microsporidia spores to the surface of host cells and infectivity in vitro. In an effort to better understand adherence, we have turned our attention to determining what proteins may be involved in this process. Examination of the …


Antibiotics That Inhibit 30s Or 50s Ribosomal Subunit Formation: Hygromycin B, Quinupristin-Dalfopristin And Xrp 2868., Susan Mabe Mcgaha Dec 2007

Antibiotics That Inhibit 30s Or 50s Ribosomal Subunit Formation: Hygromycin B, Quinupristin-Dalfopristin And Xrp 2868., Susan Mabe Mcgaha

Electronic Theses and Dissertations

Several antibiotics that prevent translation by binding to ribosomal subunits have been shown to also inhibit ribosomal subunit assembly (Champney and Tober 2003). The aminoglycoside hygromycin B was examined in Escherichia coli cells for inhibitory effects on translation and ribosomal subunit assembly. The streptogramin antibiotics quinupristin-dalfopristin and XRP 2868 (NXL 103) were examined for similar effects on these 2 cellular functions in antibiotic-resistant strains of Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae.

Pulse chase experiments were performed which verified slower rates of ribosomal subunit formation in drug treated cells. Hygromycin B exhibited a concentration dependent inhibitory effect …


Intake Of Coffee And Tea And Risk Of Ovarian Cancer: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Meera Jain, Geoffrey R. Howe, Anthony B. Miller, Thomas E. Rohan Dec 2007

Intake Of Coffee And Tea And Risk Of Ovarian Cancer: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Meera Jain, Geoffrey R. Howe, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

There is some evidence from case-control studies that coffee consumption might be positively associated with ovarian cancer risk, whereas the epidemiologic evidence regarding tea consumption and ovarian cancer is inconsistent. To date, there have been few prospective studies of these associations. Therefore, we examined ovarian cancer risk in association with both coffee and tea intake in a prospective cohort study of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending …


A Quantitative Synthesis Of The Medicinal Ethnobotany Of The Malinké Of Mali And The Asháninka Of Peru, With A New Theoretical Framework, Nathaniel Bletter Dec 2007

A Quantitative Synthesis Of The Medicinal Ethnobotany Of The Malinké Of Mali And The Asháninka Of Peru, With A New Theoretical Framework, Nathaniel Bletter

Publications and Research

Background: Although ethnomedically and taxonomically guided searches for new medicinal plants can improve the percentage of plants found containing active compounds when compared to random sampling, ethnobotany has fulfilled little of its promise in the last few decades to deliver a bounty of new, laboratory-proven medicinal plants and compounds. It is quite difficult to test, isolate, and elucidate the structure and mechanism of compounds from the plethora of new medicinal plant uses described each year with limited laboratory time and resources and the high cost of clinical trials of new drug candidates.

Methods: A new quantitative theoretical framework of mathematical …


Enzyme Architecture And Flexibility Affect Dna Topoisomerase I Function, Mariè Van Der Merwe Dec 2007

Enzyme Architecture And Flexibility Affect Dna Topoisomerase I Function, Mariè Van Der Merwe

Theses and Dissertations (ETD)

DNA topoisomerase I (Top1) is a highly conserved enzyme composed of four domains: a positively charged N-terminus; a DNA binding/core domain that circumscribes duplex DNA; a non-conserved linker domain; and a C-terminal/catalytic domain. Top1 catalyzes changes in DNA topology by transient cleavage of a single DNA strand and the concomitant formation of a phosphotyrosyl linkage between the enzyme and the 3’ DNA end. This covalent Top1-DNA complex is the binding site for camptothecin (CPT), which selectively inhibits religation of the cleaved DNA strand. CPT binding stabilizes the covalent complex, while the collision of replication forks with CPT-Top1-DNA adducts produces DNA …


The Role Of Multi-Drug Resistance Associated Protein 4 And P-Glycoprotein In Resistance Of Neuroblastoma To Topotecan And Irinotecan, Patricia Kellie Turner Dec 2007

The Role Of Multi-Drug Resistance Associated Protein 4 And P-Glycoprotein In Resistance Of Neuroblastoma To Topotecan And Irinotecan, Patricia Kellie Turner

Theses and Dissertations (ETD)

High-risk neuroblastoma presents a significant therapeutic challenge because the 5-year survival rate remains less than 30% despite the use of surgery, multi-agent chemotherapy, radiation, and autologous bone marrow transplant. Novel therapeutic modalities are under development. The camptothecin analogs topotecan and irinotecan have been identified as successful cytotoxic agents. For topotecan, pharmacokinetically guided dosing to achieve a systemic exposure associated with preclinical anti-tumor activity in neuroblastoma xenograft models is feasible and has elicited favorable responses in children with high-risk neuroblastoma. However, some children with high-risk disease did not respond to the putatively effective topotecan systemic exposure. These children represent a subset …


Micro Rna 145 Targets The Insulin Receptor Substrate-1 And Inhibits The Growth Of Colon Cancer Cells, Bin Shi, Laura Sepp-Lorenzino, Marco Prisco, Peter Linsley, Tiziana Deangelis, Renato Baserga Nov 2007

Micro Rna 145 Targets The Insulin Receptor Substrate-1 And Inhibits The Growth Of Colon Cancer Cells, Bin Shi, Laura Sepp-Lorenzino, Marco Prisco, Peter Linsley, Tiziana Deangelis, Renato Baserga

Department of Cancer Biology Faculty Papers

The insulin receptor substrate-1 (IRS-1), a docking protein for both the type 1 insulin-like growth factor receptor (IGF-IR) and the insulin receptor, is known to send a mitogenic, anti-apoptotic, and anti-differentiation signal. Several micro RNAs (miRs) are suggested by the data base as possible candidates for targeting IRS-1. We show here that one of the miRs predicted by the data base, miR145, whether transfected as a synthetic oligonucleotide or expressed from a plasmid, causes down-regulation of IRS-1 in human colon cancer cells. IRS-1 mRNA is not decreased by miR145, while it is down-regulated by an siRNA targeting IRS-1. Targeting of …


Anopheles Gambiae Purine Nucleoside Phosphorylase: Catalysis, Structure And Inhibition, Erika Taylor, Agnes Rinaldo-Matthis, Lei Li, Mahmoud Ghanem, Keith Hazleton, M. Belen Cassera, Steven Almo, Vern Schramm Oct 2007

Anopheles Gambiae Purine Nucleoside Phosphorylase: Catalysis, Structure And Inhibition, Erika Taylor, Agnes Rinaldo-Matthis, Lei Li, Mahmoud Ghanem, Keith Hazleton, M. Belen Cassera, Steven Almo, Vern Schramm

Erika A. Taylor, Ph.D.

The purine salvage pathway of Anopheles gambiae, a mosquito that transmits malaria, has been identified in genome searches on the basis of sequence homology with characterized enzymes. Purine nucleoside phosphorylase (PNP) is a target for the development of therapeutic agents in humans and purine auxotrophs, including malarial parasites. The PNP from Anopheles gambiae (AgPNP) was expressed in Escherichia coli and compared to the PNPs from Homo sapiens (HsPNP) and Plasmodium falciparum (PfPNP). AgPNP has kcat values of 54 and 41 s-1 for 2'-deoxyinosine and inosine, its preferred substrates, and 1.0 s-1 for guanosine. However, the chemical step is fast for …


Sirtuins, Nuclear Hormone Receptor Acetylation And Transcriptional Regulation, James R. Whittle, Michael J. Powell, Vladimir M. Popov, L. Andrew Shirley, Chenguang Wang, Richard G. Pestell Oct 2007

Sirtuins, Nuclear Hormone Receptor Acetylation And Transcriptional Regulation, James R. Whittle, Michael J. Powell, Vladimir M. Popov, L. Andrew Shirley, Chenguang Wang, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Endocrine signaling via nuclear receptors (NRs) is known to play an important role in normal physiology as well as in human tumor progression. Hormones regulate gene expression by altering local chromatin structure and, thereby, accessibility of transcriptional co-regulators to DNA. Recently it has been shown that non-histone proteins involved in hormone signaling, such as nuclear receptors and NR co-activators, are regulated by acetylation, resulting in their altered transcriptional activity. NAD-dependent protein deacetylases, the sirtuins (Sir2-related enzymes), directly modify NRs. Because sirtuins have been shown to regulate tumor cellular growth, aging, metabolic signaling and endocrine hormone signaling, they might play a …


In Vivo Construction Of Recombinant Molecules Within The Caenorhabditis Elegans Germ Line Using Short Regions Of Terminal Homology, Benedict J. Kemp, Julia Hatzold, Laura A. Sternick, Joshua Cornman-Homonoff, Jessica M. Whitaker, Pamela J. Tieu, Eric J. Lambie Sep 2007

In Vivo Construction Of Recombinant Molecules Within The Caenorhabditis Elegans Germ Line Using Short Regions Of Terminal Homology, Benedict J. Kemp, Julia Hatzold, Laura A. Sternick, Joshua Cornman-Homonoff, Jessica M. Whitaker, Pamela J. Tieu, Eric J. Lambie

Dartmouth Scholarship

Homologous recombination provides a means for the in vivoconstruction of recombinant DNA molecules that may be problematic to assemble in vitro . We have investigated the efficiency of recombination within the Caenorhabditis elegans germ line as a function of the length of homology between recombining molecules. Our findings indicate that recombination can occur between molecules that share only 10 bp of terminal homology, and that 25 bp is sufficient to mediate relatively high levels of recombination. Recombination occurs with lower efficiency when the location of the homologous segment is subterminal or internal. As in yeast, recombination can also be …


Phenylalanyl-Trna Synthetase Editing Defects Result In Efficient Mistranslation Of Phenylalanine Codons As Tyrosine, Jiqiang Ling, Srujana S. Yadavalli, Michael Ibba Sep 2007

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 Sep 2007

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 kcat …


The Effects Of Nicotine Conditioned Place Preference In D2 Primed Adolescent Rats: Age-Related And Gender Effects., Yoko Emily Ogawa Aug 2007

The Effects Of Nicotine Conditioned Place Preference In D2 Primed Adolescent Rats: Age-Related And Gender Effects., Yoko Emily Ogawa

Electronic Theses and Dissertations

This study investigated nicotine conditioned place preference (CPP) in two different ages of adolescence using a rodent model of schizophrenia. Both 2- and 3-chambered CPP apparatuses were used to test whether the CPP was due to an aversion to the white chamber. Animals were neontally treated with the dopamine D2/D3 agonist, quinpirole, or saline and raised to either early postweanling age (P 22) or adolescence (P 29). Rats were conditioned to prefer the white chamber using nicotine. Results showed that nicotine induced CPP and appeared to alleviate an increased stress response in D2 primed animals, which …


Stabilization Of Smar1 Mrna By Pga2 Involves A Stem Loop Structure In The 5' Utr, Lakshminarasimhan Pavritha, Shravanti Rampalli, Surajit Sinha, Kadreppa Sreenath, Richard G. Pestell, Samit Chattopadhyay Aug 2007

Stabilization Of Smar1 Mrna By Pga2 Involves A Stem Loop Structure In The 5' Utr, Lakshminarasimhan Pavritha, Shravanti Rampalli, Surajit Sinha, Kadreppa Sreenath, Richard G. Pestell, Samit Chattopadhyay

Department of Cancer Biology Faculty Papers

Prostaglandins are anticancer agents known to inhibit tumor cell proliferation both in vitro and in vivo by affecting the mRNA stability. Here we report that a MAR-binding protein SMAR1 is a target of Prostaglandin A2 (PGA2) induced growth arrest. We identify a regulatory mechanism leading to stabilization of SMAR1 transcript. Our results show that a minor stem and loop structure present in the 5' UTR of SMAR1 (1-UTR) is critical for nucleoprotein complex formation that leads to SMAR1 stabilization in response to PGA2. This results in an increased SMAR1 transcript and altered protein levels, that in turn causes downregulation of …


The Effect Of Mtad On Eight Strains Of E. Faecalis In Contaminated Root Canals, Bradley M. Newberry Aug 2007

The Effect Of Mtad On Eight Strains Of E. Faecalis In Contaminated Root Canals, Bradley M. Newberry

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to determine the antimicrobial effect of Biopure MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) as a final irrigant on eight strains of Enterococcus faecalis (E. faecalis) in contaminated root canals of extracted human teeth. In addition, the Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) of MTAD were also measured on the same strains of bacteria. Two-hundred and forty extracted human teeth were instrumented using 1.3% NaOCl followed by 17% EDTA to remove the smear layer. The teeth were randomly contaminated with one of eight strains of E. …


Plant-Derived Epcam Antigen Induces Protective Anti-Cancer Response., Robert Brodzik, Sergei Spitsin, Max Golovkin, Katarzyna Bandurska, Carla Portocarrero, Monika Okulicz, Zenon Steplewski, Hilary Koprowski Jul 2007

Plant-Derived Epcam Antigen Induces Protective Anti-Cancer Response., Robert Brodzik, Sergei Spitsin, Max Golovkin, Katarzyna Bandurska, Carla Portocarrero, Monika Okulicz, Zenon Steplewski, Hilary Koprowski

Department of Cancer Biology Faculty Papers

Immunotherapy holds great promise for treatment of infectious and malignant diseases and might help to prevent the occurrence and recurrence of cancer. We produced a plant-derived tumor-associated colorectal cancer antigen EpCAM (pGA733) at high yields using two modern plant expression systems. The full antigenic domain of EpCAM was efficiently purified to confirm its antigenic and immunogenic properties as compared to those of the antigen expressed in the baculovirus system (bGA733). Recombinant plant-derived antigen induced a humoral immune response in BALB/c mice. Sera from those mice efficiently inhibited the growth of SW948 colorectal carcinoma cells xenografted in nude mice, as compared …


Autocrine Prolactin Promotes Prostate Cancer Cell Growth Via Janus Kinase-2-Signal Transducer And Activator Of Transcription-5a/B Signaling Pathway., Ayush Dagvadorj, Sean Collins, Jean-Baptiste Jomain, Junaid Abdulghani, James Karras, Tobias Zellweger, Hongzhen Li, Martti Nurmi, Kalle Alanen, Tuomas Mirtti, Tapio Visakorpi, Lukas Bubendorf, Vincent Goffin, Marja T Nevalainen Jul 2007

Autocrine Prolactin Promotes Prostate Cancer Cell Growth Via Janus Kinase-2-Signal Transducer And Activator Of Transcription-5a/B Signaling Pathway., Ayush Dagvadorj, Sean Collins, Jean-Baptiste Jomain, Junaid Abdulghani, James Karras, Tobias Zellweger, Hongzhen Li, Martti Nurmi, Kalle Alanen, Tuomas Mirtti, Tapio Visakorpi, Lukas Bubendorf, Vincent Goffin, Marja T Nevalainen

Department of Cancer Biology Faculty Papers

The molecular mechanisms that promote progression of localized prostate cancer to hormone-refractory and disseminated disease are poorly understood. Prolactin (Prl) is a local growth factor produced in high-grade prostate cancer, and exogenously added Prl in tissue or explant cultures of normal and malignant prostate is a strong mitogen and survival factor for prostate epithelium. The key signaling proteins that mediate the biological effects of Prl in prostate cancer are Signal Transducer and Activator of Transcription (Stat)-5a/5b via activation of Janus kinase-2. Importantly, inhibition of Stat5a/b in prostate cancer cells induces apoptotic death. Using a specific Prl receptor antagonist (Delta1-9G129R-hPRL), we …


Transition-State Variation In Human, Bovine, And Plasmodium Falciparum Adenosine Deaminases, Minkui Lou, Vipender Singh, Erika Taylor, Vern Schramm May 2007

Transition-State Variation In Human, Bovine, And Plasmodium Falciparum Adenosine Deaminases, Minkui Lou, Vipender Singh, Erika Taylor, Vern Schramm

Erika A. Taylor, Ph.D.

Adenosine deaminases (ADAs) from human, bovine, and Plasmodium falciparum sources were analyzed by kinetic isotope effects (KIEs) and shown to have distinct but related transition states. Human adenosine deaminase (HsADA) is present in most mammalian cells and is involved in B- and T-cell development. The ADA from Plasmodium falciparum (PfADA) is essential in this purine auxotroph, and its inhibition is expected to have therapeutic effects for malaria. Therefore, ADA is of continuing interest for inhibitor design. Stable structural mimics of ADA transition states are powerful inhibitors. Here we report the transition-state structures of PfADA, HsADA, and bovine ADA (BtADA) solved …


An Analysis Of Nicotine Exacerbation Of Reductions In Ppi In A Rodent Model Of Schizophrenia., Amanda Marie Maple May 2007

An Analysis Of Nicotine Exacerbation Of Reductions In Ppi In A Rodent Model Of Schizophrenia., Amanda Marie Maple

Electronic Theses and Dissertations

Prepulse inhibition (PPI) is an operational measure of sensorimotor gating and is known to be reduced when the dopamine D2 receptor is activated. We used a rodent model of psychosis in which increases in dopamine D2 receptor sensitivity are produced through neonatal quinpirole (a dopamine D2 / D3 agonist) treatment to rats. Rats were administered quinpirole (1mg/kg) or saline from postnatal day (P) 1-21. Rats were raised to adulthood and tested on PPI. Results showed that neonatal quinpirole treatment produced a significant reduction in PPI, and nicotine exacerbated this reduction. This reduction was partially blocked by …


Nicotine Sensitization In A Rodent Model Of Schizophrenia: A Comparison Of Adolescents, Adults, And Neurotrophic Factors., Marla Kay Perna May 2007

Nicotine Sensitization In A Rodent Model Of Schizophrenia: A Comparison Of Adolescents, Adults, And Neurotrophic Factors., Marla Kay Perna

Electronic Theses and Dissertations

The behavioral effects of nicotine on locomotor activity in a rodent model of psychosis were analyzed. This model is based on neonatal quinpriole treatment (a dopamine D2/D3 agonist) which causes increased D2 receptor sensitivity, a phenomenon known as D2 priming that is common in schizophrenia. D2-primed adolescent rats did not demonstrate nicotine-induced hypoactivity early in training, and males demonstrated more rapid sensitization to nicotine as compared to controls administered nicotine. D2-primed females administered nicotine demonstrated increased stereotypic behavior. D2-primed adult rats given nicotine demonstrated significantly more robust sensitization to nicotine than controls given nicotine. Brain-derived neurotrophic factor (BDNF) was analyzed …


Biochemical Characteristics Of Inconsistent Free T₄ Assays, Kristofer S. Fritz May 2007

Biochemical Characteristics Of Inconsistent Free T₄ Assays, Kristofer S. Fritz

Loma Linda University Electronic Theses, Dissertations & Projects

Serum levels of free thyroxine (T4) are helpful in the clinical evaluation of patients who are suspected of having thyroid disease, since free T4 (unbound) is known to closely relate to hyper, eu and hypothyroidism. There are documented inconsistencies among commercially available direct free thyroxine immunoassays. The biochemical basis for these inconsistencies is not understood and has not been characterized. Direct free T4 measurements have been linked to both T4-binding serum protein concentrations and protein-bound T4 concentrations. A free T4 reference method using direct equilibrium dialysis radioimmunoassay has been well characterized. New …


The Effect Of Radiation And Repeated Sub-Culturing On Tgf-Β1 Signaling In Frtl-5 Cells, Cheryl G. Burrell May 2007

The Effect Of Radiation And Repeated Sub-Culturing On Tgf-Β1 Signaling In Frtl-5 Cells, Cheryl G. Burrell

Loma Linda University Electronic Theses, Dissertations & Projects

From our ongoing in vitro studies using the Fisher Rat Thyroid cell line-5 (FRTL-5) we recorded accelerated growth, reduced follicularization and reduction in thyroxin release that occurred as the cells were repeatedly sub-cultured. We also recorded that these changes occurred earlier and more rapidly following radiation exposure. We determined that TGF-β1 production increased under both conditions. We hypothesized that alteration in the TGF-β1 signaling pathway contributed to the changes observed in the cellular properties of FRTL-5 cells. Our objective was to examine some of the players in the TGF-β1 signaling pathway to determine whether radiation and/or repeated subculturing promoted changes …


Acyclic Ribooxacarbenium Ion Mimics As Transition State Analogues Of Human And Malarial Purine Nucleoside Phosphorylases, Erika Taylor, Keith Clinch, Peter Kelly, Lei Li, Gary Evans, Peter Tyler, Vern Schramm Apr 2007

Acyclic Ribooxacarbenium Ion Mimics As Transition State Analogues Of Human And Malarial Purine Nucleoside Phosphorylases, Erika Taylor, Keith Clinch, Peter Kelly, Lei Li, Gary Evans, Peter Tyler, Vern Schramm

Erika A. Taylor, Ph.D.

Transition state analogues of PNP, the Immucillins and DADMe-Immucillins, were designed to match transition state features of bovine and human PNPs, respectively. A third generation of inhibitors has been designed that contain an acyclic iminoalcohol to replace the cyclic mimic of the ribooxacarbenium ion at the transition states of PNPs. The best third generation inhibitor is equivalent to the best inhibitors found in the previous transition state analogues.


Synthesis Of 5‘-Methylthio Coformycins:  Specific Inhibitors For Malarial Adenosine Deaminase, Peter Tyler, Erika Taylor, Richard Froehlich, Vern Schramm Apr 2007

Synthesis Of 5‘-Methylthio Coformycins:  Specific Inhibitors For Malarial Adenosine Deaminase, Peter Tyler, Erika Taylor, Richard Froehlich, Vern Schramm

Erika A. Taylor, Ph.D.

Transition state theory suggests that enzymatic rate acceleration (kcat/knon) is related to the stabilization of the transition state for a given reaction. Chemically stable analogues of a transition state complex are predicted to convert catalytic energy into binding energy. Because transition state stabilization is a function of catalytic efficiency, differences in substrate specificity can be exploited in the design of tight-binding transition state analogue inhibitors. Coformycin and 2‘-deoxycoformycin are natural product transition state analogue inhibitors of adenosine deaminases (ADAs). These compounds mimic the tetrahedral geometry of the ADA transition state and bind with picomolar dissociation constants to enzymes from bovine, …


Effects Of Angiotensin 1-7 On The Actions Of Angiotensin Ii In The Renal And Mesenteric Vasculature Of Hypertensive And Streptozotocin-Induced Diabetic Rats, Mohd Rais Mustafa, Murugan Dharmani, Francis I. Achike, Meng-Kwoon Sim Apr 2007

Effects Of Angiotensin 1-7 On The Actions Of Angiotensin Ii In The Renal And Mesenteric Vasculature Of Hypertensive And Streptozotocin-Induced Diabetic Rats, Mohd Rais Mustafa, Murugan Dharmani, Francis I. Achike, Meng-Kwoon Sim

Mohd Rais Mustafa

Angiotensin 1-7, a heptapeptide derived from metabolism of either angiotensin I or angiotensin II, is a biologically active peptide of the renin–angiotensin system. The present study investigated the effect of angiotensin 1-7 on the vasopressor action of angiotensin II in the renal and mesenteric vasculature of Wistar-Kyoto (WKY) rats, spontaneously hypertensive rats (SHR) and streptozotocin-induced diabetic rats. Angiotensin II-induced dose-dependent vasoconstrictions in the renal vasculature. The pressor response was enhanced in the SHR and reduced in the streptozotocin-diabetic rat compared to WKY rats. Angiotensin 1-7 attenuated the angiotensin II pressor responses in the renal vasculature of WKY and SHR rats. …


Smallpox Subunit Vaccine Produced In Planta Confers Protection In Mice, Maxim Golovkin, Sergei Spitsin, Vyacheslav Andrianov, Yuriy Smirnov, Yuhong Xiao, Natalia Pogrebnyak, Karen Markley, Robert Brodzik, Yuri Gleba, Stuart N Isaacs, Hilary Koprowski Apr 2007

Smallpox Subunit Vaccine Produced In Planta Confers Protection In Mice, Maxim Golovkin, Sergei Spitsin, Vyacheslav Andrianov, Yuriy Smirnov, Yuhong Xiao, Natalia Pogrebnyak, Karen Markley, Robert Brodzik, Yuri Gleba, Stuart N Isaacs, Hilary Koprowski

Department of Cancer Biology Faculty Papers

We report here the in planta production of the recombinant vaccinia virus B5 antigenic domain (pB5), an attractive component of a subunit vaccine against smallpox. The antigenic domain was expressed by using efficient transient and constitutive plant expression systems and tested by various immunization routes in two animal models. Whereas oral administration in mice or the minipig with collard-derived insoluble pB5 did not generate an anti-B5 immune response, intranasal administration of soluble pB5 led to a rise of B5-specific immunoglobulins, and parenteral immunization led to a strong anti-B5 immune response in both mice and the minipig. Mice immunized i.m. with …


Scope: A Web Server For Practical De Novo Motif Discovery, Jonathan M. Carlson, Arijit Chakravarty, Charles E. Deziel, Robert H. Gross Apr 2007

Scope: A Web Server For Practical De Novo Motif Discovery, Jonathan M. Carlson, Arijit Chakravarty, Charles E. Deziel, Robert H. Gross

Dartmouth Scholarship

SCOPE is a novel parameter-free method for the de novoidentification of potential regulatory motifs in sets of coordinately regulated genes. The SCOPE algorithm combines the output of three component algorithms, each designed to identify a particular class of motifs. Using an ensemble learning approach, SCOPE identifies the best candidate motifs from its component algorithms. In tests on experimentally determined datasets, SCOPE identified motifs with a significantly higher level of accuracy than a number of other web-based motif finders run with their default parameters. Because SCOPE has no adjustable parameters, the web server has an intuitive interface, requiring only a …


Stability Of Eukaryotic Elongation Factor One Alpha Protein In The Cell, Jennifer Watry Apr 2007

Stability Of Eukaryotic Elongation Factor One Alpha Protein In The Cell, Jennifer Watry

Honors Theses

Eukaryotic Elongation Factor One Alpha (eEF1A) is an abundant protein found in every cell of every organism and is involved in functions concerning protein synthesis and degradation, the cytoskeleton, and signaling. How these functions are regulated is not yet understood for this protein. Regulation of the protein may be controlled by transcription of the genes encoding the protein or the stability and modification of the protein. The goal of this project was to determine the stability of eEf1A proteins in Arabidopsis thaliana. Protein stability was determined by treating tissues with cycloheximide, an inhibitor of protein synthesis. Gel electrophoresis and …