Life Sciences Commons^™

Vimentin Overexpression Contributes To The Biological Properties Of Metastatic Head And Neck Cancer Cells, Rachel J. Paccione

Theses and Dissertations

Epithelial to mesenchymal transition occurs in the later stages of epithelial tumor progression, with cells expressing mesenchymal markers. Of these, the intermediate filament protein vimentin is frequently upregulated in metastatic carcinomas. Previously, microarray studies showed that the gene encoding vimentin is highly upregulated in metastatic HN12 cells compared to a related primary tumor cell line. In this study, we confirmed this difference using real-time quantitative PCR, western blot analysis, and immunostaining. Furthermore, EGF and TGF-β, growth factors that induce migration and invasion of HN12 cells, produced synergistic increases in vimentin expression. To assess the contribution of vimentin to the biological …

Type-5 Phosphodiesterase Inhibition In The Prevention Of Doxorubicin Cardiomyopathy, Patrick William Fisher

Theses and Dissertations

Prior studies have demonstrated the effect of diazoxide in protecting against apoptosis via mitochondrial KATP channel opening in vitro. The current investigations are designed to determine if sildenafil, a phosphodiesterase-5 inhibitor and known mitochondrial KATP channel opener, would protect against chronic doxorubicin cardiomyopathy both in vivo and in vitro.Male ICR mice were randomized to 1 of 4 treatments: saline, sildenafil (0.7 mg/kg IP), doxorubicin (5 mg/kg IP), and sildenafil (0.7 mg/kg IP)+doxorubicin. Apoptosis was determined using the terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling and in situ oligo ligation methods. Desmin distribution was determined via immunofluorescence. Bcl-2 was analyzed by …

The Effect Of Loading On Disturbance Sounds Of The Atlantic Croaker Micropogonius Undulatus: Air Versus Water, Michael L. Fine, Justin Schrinel, Timothy M. Cameron

Biology Publications

Physiological work on fish sound production may require exposure of the swimbladder to air, which will change its loading (radiation mass and resistance) and could affect parameters of emitted sounds. This issue was examined in Atlantic croaker Micropogonius chromis by recording sounds from the same individuals in air and water. Although sonograms appear relatively similar in both cases, pulse duration is longer because of decreased damping, and sharpness of tuning (Q factor) is higher in water. However, pulse repetition rate and dominant frequency are unaffected. With appropriate caution it is suggested that sounds recorded in air can provide a useful …

Seeding The Universe With Life: Securing Our Cosmological Future, Michael Noah Mautner

Chemistry Publications

Life is unique in Nature, and for us, it is precious. Life is unique in its complex patterns, and in its purposeful self-continuation. We belong to life and share its drive for self-propagation. Belonging to life then implies a human purpose to secure, expand and propagate our family of gene/protein life.

This purpose is best achieved in space, where life has an immense future. We can start now to secure this future, by seeding with life new solar systems. New species can develop there into intelligent beings who will further expand life in the galaxy. Filling the universe with life …

Regulation Of Fc Receptor Expression And Signaling On Murine Mast Cells, Hey Jin Chong

Theses and Dissertations

Mast cells have long been appreciated as the primary effector cells in allergy and asthma, and recently have been implicated in other inflammatory diseases. Using high density oligonucleotide probe arrays, we assessed genome-wide transcriptional profiles after FcεRI aggregation for 90 minutes, 5 hours and 24 hours. We describe novel gene regulation in response to FcεRI signaling, including altered expression of CD44, Pari, osteopontin, Nur77, E4BP4, and NDRG 1. In addition, the gene encoding FcεRI β was downregulated 5 hours after mast cell activation according to both microarray analysis and RPA, and western blotting confirmed the downregulation of the beta subunit …

Effects Of Emphysema And Chronic Hypoxemia On Skeletal Muscle Oxygen Supply And Demand, John D. Lowman Jr.

Theses and Dissertations

Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD) is a condition in which peripheral skeletal muscle undergoes myopathic changes which impair muscle function, limit physical performance, and can lead to significant disability. While the etiology of the dysfunction is unknown, this study was conducted to test the hypothesis that chronic hypoxemia leads to alterations in oxygen transport and muscle function. A primary objective was to validate elastase-induced emphysema in rats as an animal model of skeletal muscle dysfunction in COPD.Arterial blood gases were used to determine the severity of hypoxemia and sodium dodecyl sulfate- polyacrylamide gel electrophoresis was used …

Surface Characteristics Of Bacillus Spores, Darlene Danette Sabio

Theses and Dissertations

Rapid isolation and identification of spores from various environmental samples is necessitated because anthrax spores can be used as biological weapons. The hydrophobic nature of spores may allow for their rapid concentration and partial purification from contaminating materials. In this study, spores from four taxonomic groups of Bacillaceae were isolated, purified and characterized for hydrophobicity by hexadecane partitioning, surface morphology by scanning electron microscopy, and steady-state fluorescence by spectroscopy. The morphology of spores was similar within taxonomic groups and dissimilar between groups. Spore hydrophobicity ranged from 0.3% to 65% and all spores had fluorescence emission peaks at 335 nm and …

Acoustic Communication In Two Freshwater Gobies: Ambient Noise And Short-Range Propagation In Shallow Streams, Marco Lugli, Michael L. Fine

Biology Publications

Noise is an important theoretical constraint on the evolution of signal form and sensory performance. In order to determine environmental constraints on the communication of two freshwater gobies Padogobius martensii and Gobius nigricans, numerous noise spectra weremeasured from quiet areas and ones adjacent to waterfalls and rapids in two shallow stony streams. Propagation of goby sounds and waterfall noise was also measured. A quiet window around 100 Hz is present in many noise spectra from noisy locations. The window lies between two noise sources, a low-frequency one attributed to turbulence, and a high-frequency one (200–500 Hz) attributed to bubble …

Vascular Cell Dysfunction And Transendothelial Migration Of Neutrophils In Preeclampsia, Courtney Elizabeth Leik

Theses and Dissertations

Oxidative stress, hyperlipidemia, neutrophil activation and endothelial cell dysfunction are characteristic of women with preeclampsia. We used in vitro experiments to test if a combination of oxidative stress and linoleic acid favors a mechanism for neutrophil transendothelial migration. We used linoleic acid because it is one of the fatty acids elevated in preeclampsia and the precursor for arachidonic acid and its inflammatory metabolites. For these studies, we developed a methodology for isolating and Culturing human vascular smooth muscle cells from placental chorionic plate arteries. Treatment of these cells with an oxidizing solution enriched with linoleic acid, but neither component alone, …

Planetary Bioresources And Astroecology 1. Planetary Microcosm Bioassays Of Martian And Carbonaceous Chondrite Materials: Nutrients, Electrolyte Solutions, And Algal And Plant Responses, Michael Noah Mautner

Chemistry Publications

The biological fertilities of planetary materials can be assessed using microcosms based on materials in martian and carbonaceous chondrite meteorites. Their biological fertilities are rated based on soluble electrolyte nutrients, on the growth of mesophile and cold-tolerant algae, and of plant tissue cultures. The Murchison CM2 carbonaceous chondrite meteorite and DaG 476 martian shergottite contain high levels of water-extractable Ca, Mg, and SO4–S. The martian meteorites DaG 476 and EETA 79001 also contain high levels of extractable nutrients NO3–N (0.013–0.017 g kg⁻¹) and PO4–P (0.019–0.046 g kg⁻¹). The yields of most of the water-extractable …

Cyanonews (Vol. 17, No. 1, 2002), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

Acoustic Competition In The Gulf Toadfish Opsanus Beta: Acoustic Tagging, Robert F. Thorson, Michael L. Fine

Biology Publications

Nesting male gulf toadfish Opsanus beta produce a boatwhistle advertisement call used in male–male competition and to attract females and an agonistic grunt call. The grunt is a short-duration pulsatile call, and the boatwhistle is a complex call typically consisting of zero to three introductory grunts, a long tonal boop note, and zero to three shorter boops. The beginning of the boop note is also gruntlike. Anomalous boatwhistles contain a short-duration grunt embedded in the tonal portion of the boop or between an introductory grunt and the boop. Embedded grunts have sound-pressure levels and frequency spectra that correspond with those …

Cyanonews (Vol. 16, No. 1, December 2001), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

Cyanonews (Vol. 15, No. 1, July 2000), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

Functional Characterization Of Mitogen-Dependent And Self-Perpetuating Nb2 Lymphoma Cell Lines, Charlotte Cockrell

Theses and Dissertations

This investigation involved the functional characterization of four Nb2 sub lines (Nb2-U- 17, Nb2-l l , SFJCD l , and D5) for their mitogenic and apoptotic responses to DEX ± PRL treatment. Many protein factors have been implicated to be crucial in controlling the apoptotic and mitogenic pathways. In conjunction with functional studies, an immunocytochemical investigation of four protein signals (NFKB, IKBa, STAT 5b, and the GR) was undertaken in an attempt to establish a relationship between the functional responsiveness of a given cell line and the concentration of a particular protein marker. Comparison of the functional data obtained for …

Studies On The Role Creb As A Mediator Of Neurotrophin-3 Actions In Oligodendrocytes, Jamie Richard Johnson

Theses and Dissertations

In the central nervous system (CNS), oligodendrocytes (OLGs) are the cells responsible for producing the myelin membrane which allows for the saltatory conduction of neuronal impulses. We have previously shown that CREB (cAMP response element binding protein), a transcription factor that belongs to a large family bZip (basic leucine zipper) proteins, could be a mediator of neuronal signals that, coupled to different signal transduction pathways, may play different regulatory roles at specific stages of oligodendrocyte development. We have found before that, in committed OLGs, CREB activation by phosphorylation can be triggered by β-adrenergic stimulation and appears to play a role …

Characterization Of Rat Pulmonary Carboxylesterase, Timothy J. Wallace

Theses and Dissertations

The 1839 bp cDNA for rat pulmonary carboxylesterase was cloned by reverse transcription polymerase chain reaction (RT PCR) from total rat lung RNA using specific primers derived from the 5' and 3' untranslated regions of rat hepatic cholesteryl ester hydrolase (CEH). The unique cDNA was sequenced and found to have 99% homology with hepatic CEH. This homology extends to the predicted amino acid sequences which show only six amino acid residue differences in the coding region: three conserved and three nonconserved changes. However, the catalytic activitites of the two proteins are dramatically different. While CEH hydrolyzes cholesterol oleate, the pulmonary …

The Roles Of Several Kinases In Mice Tolerant To Delta-9-Tetrahydrocannabinol, Matthew C. Lee

Theses and Dissertations

It has been suggested that the CB1 G-protein-coupled receptor is internalized following agonist binding and activation of the second messenger pathways. The process of desensitization and resensitization is intimately involved with receptor internalization. Phosphorylation alters tolerance to cannabinoids thus contributing to tolerance. It is proposed that phosphorylation enhances the down-regulation of the CB1 receptor. These findings led us to look at which kinase(s) may be involved in cannabinoid tolerance. We therefore hypothesize that by preventing phosphorylation of the CB1 receptor, we may reverse tolerance. We evaluated our hypothesis by testing the role of several kinases in tolerance: protein kinase A …

Examination Of Signals Involved In Dexamethasone Induced Apoptosis In Nb2 Lymphoma Cells, Suhas Badarinath

Theses and Dissertations

Consistent with previous studies, we demonstrated that dexamethasone (Dex) caused cytolysis/apoptosis in log phase Nb2 lymphoma cells, while prolactin (Prl) inhibited this effect. The Nb2 model was used to investigate the mechanisms of apoptosis control with the aid of immunocytochemistry (ICC). We established with absorption the specificity of staining due to Fas, Fas Ligand, Bcl-2, and Bax antibodies (the specificity of anti-p53 could not be verified). Dex-induced cytolysis/apoptosis was detected in synchronized (G⁰/G¹) cells after 6 and 8 hours of Dex exposure. A novel, computerized technique was used to quantitate the proportion of cells immunostained for the signals of interest …

Correlation Of Visualized Glucocorticoid Receptor And Apoptosis In Individual Clones Of Nb2 Cells, Devang M. Patel

Theses and Dissertations

The Nb2 lymphoma cell line is susceptible to glucocorticoid (GC)-induced apoptosis in the absence of mitogen and this effect is inhibited by the mitogen prolactin (PRL). This process is believed to be mediated by the glucocorticoid receptor (GR) and various downstream signals. The purpose of this study was to use the limiting dilution method to isolate subsets of Nb2 clones which expressed either highly enriched amounts of GR or an absence of GR and to relate the amount of GR to the magnitude of GC induced cytolysis. The presence of GR in these clones was determined by immunocytochemistry (ICC) using …

Cyanonews (Vol. 14, No. 1, August 1998), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

Chemical Synthesis, Bacterial Expression, And Characterization Of Pro-Gnrh/Gap, A Precursor Protein Of Two Biologically Active Peptide Hormones, Louis E. Mcadory

Theses and Dissertations

Two biologically active peptides, gonadotropin releasing hormone (GnRH) and GnRH associated peptide (GAP) are both derived from a common prohormone precursor protein, pro-GnRH/GAP. Both peptides are cosecreted from hypothalamic neurosecretory granules and are involved in the regulation of mammalian reproduction. A calcium dependent, neutral pH serine protease discovered in this laboratory, GAP-releasing enzyme, is the most likely processing enzyme of pro-GnRH/GAP. GAP-releasing enzyme is immunologically related to PC1/3, a member of the prohormone convertase (PC) class of processing endoproteinases.

GAP-releasing enzyme recognizes the eight residue processing site within pro-GnRH/GAP, G⁶LRPGGKR¹³, and correctly cleaves the R^{13 …}

Determination Of Rates And Patterns Of Recombination At The Maize Red Color (R1) Locus, William R. Dietrich

Theses and Dissertations

Homologous recombination has been studied in many plant and animal systems. In maize, most recombination occurs intragenically. The current study assessed the frequency and location of meiotic recombination at the maize red color (r1) gene. Three independent mutant (colorless seed) alleles derived from the colored seed allele, R-sc:124, were made heterozygous with the colored plant allele, r-r:n142. Each mutant resulted from the insertion of a Dissociation (Ds) transposable element into the 3' end of R-sc:124. In the presence of Activator (Ac), each Ds insertion allele (r-sc:mutables) produced spotted seeds and germinal reversion to fully colored seeds due to the vi …

Immunocytochemical Study Of Apoptosis Signaling In Nb2 Lymphoma Cells, Angelo P. Guanzon

Theses and Dissertations

In the absence of mitogen, administration of Dexamethasone (Dex) induces apoptosis, or programmed-cell death in the Nb2 lymphoma cell. Addition of prolactin (Prl), on the other hand, blocks this effect. As a model for apoptosis, we were able to investigate this Dex-Prl interaction by means of a morphological approach: one that could be visualized under a light microscope. This approach allowed us to achieve several aims. First, we were able to develop a method of cell quantification befitting a morphological study based upon the hemacytometer. Second, with Trypan Blue exclusion, we were able to verify Dex/Prl-responsiveness in the Nb2 cells. …

Trophic Ecology Of Native And Introduced Catfishes In The Tidal James River, Virginia, Louis Fairfax Chandler

Theses and Dissertations

Species introductions have been linked to the decline of native taxa, and in many cases have resulted in the elimination of native species in both terrestrial and aquatic systems throughout the United States. In aquatic systems, a particular threat is the introduction of large piscivorous fish that may alter the native fish community structure. For example, introductions of large ictalurids such as blue catfish, (lctalurus furcatus), and flathead catfish, (Pylodictus olivaris), into coastal Virginia rivers, including the James River twenty years ago have resulted in the establishment of these large, predatory fishes.

This study described the trophic ecology of four …

Cyanonews (Vol. 13, No. 1, July 1997), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

Electrophysiological Effects Of Lysoplasmenylcholine On Rabbit Ventricular Myocytes, Ray Caldwell

Theses and Dissertations

Myocardial ischemia activates a phospholipase A2 that targets plasmalogen phospholipids and liberates 1-0-alkenyl-Iysoplasmenylcholine (LPLC) in preference to 1-0- acyl-Iysophosphatidylcholine (LPC). Although LPC is a pro arrhythmic ischemic metabolite, the effect of LPLC on cardiac electrophysiology is unknown. At the lowest doses investigated, LPLC induced spontaneous contractions in otherwise quiescent rabbit ventricular myocytes significantly faster than LPC. Spontaneous contractions developed with median times of 16.4 (n = 64), 27.4 (n = 36), and >60 min (n = 25) during exposure to 5, 2.5, and 1 JlM LPLC compared with 38.0 (n = 48) and >60 min (n = 29) for 5 …

Stem Cell Factor And Kit Expression In Type I Neurofibromatosis, Kenneth Eugene Roth

Theses and Dissertations

Neurofibromatosis type 1 (NF1) is an inherited disease characterized by the appearance of multiple neurofibromas and an increased incidence of malignant schwannomas, both of which contain hyperproliferative Schwann cells. Our laboratory previously reported that Schwann cells produce stem cell factor (SCF), a multi potential growth factor known to be involved in mast cell migration and growth. Given the fact that mast cell numbers are increased in both neurofibromas and malignant schwannomas, we set out to evaluate a potential role for SCF in the development of NF1 lesions. First we studied the effects of high doses of recombinant SCF on mast …

Estimation Of The Ld100p When P Is Small, Daniel Bettendorf

Theses and Dissertations

This thesis concerns the estimation of extreme quantiles on a dose-response curve. It focuses on the Robbins-Monro and up-and-down procedures. Simulation studies run in search of the LD15 and LD30 using a variety of methods suggest that the Robbins-Monro procedure is optimal in terms of Monte Carlo MSE and bias. The up-and-down procedure's performance differs in many cases only slightly from that of the Robbins-Monro process, therefore indicating its value as a practical alternative to the Robbins-Monro process for extreme-quantile estimation.

Molecular Cloning And Analysis Of The Promoter For Rat Hepatic Neutral Cholesterol Ester Hydrolase, Ramesh Natarajan

Theses and Dissertations

Neutral cholesterol ester hydrolase (CEH) is a key enzyme in regulating hepatic free cholesterol. Using the CEH specific cDNA sequence in the 5'-untranslated region as a primer, 1.3 kb of sequence upstream of the ATG initiation codon was amplified and cloned. Primer extension analysis with total RNA from rat primary hepatocytes identified a transcription initiation site, 60 bases upstream from the initiation codon. No typical TATA-box sequences were found upstream from the transcription start site. However, a consensus GC-box, which can bind the positive transcription factor SP1, was found 35 bases upstream from the transcription start site. In addition the …