Medicine and Health Sciences Commons^™

Embryonic Origins Of A Motor System: Motor Dendrites Form A Myotopic Map In Drosophila, Matthias Landgraf, Victoria Jeffrey, Miki Fujioka, James B. Jaynes, Michael Bate

Department of Biochemistry and Molecular Biology Faculty Papers

The organisational principles of locomotor networks are less well understood than those of many sensory systems, where in-growing axon terminals form a central map of peripheral characteristics. Using the neuromuscular system of the Drosophila embryo as a model and retrograde tracing and genetic methods, we have uncovered principles underlying the organisation of the motor system. We find that dendritic arbors of motor neurons, rather than their cell bodies, are partitioned into domains to form a myotopic map, which represents centrally the distribution of body wall muscles peripherally. While muscles are segmental, the myotopic map is parasegmental in organisation. It forms …

Protection Against Ischemia And Reperfusion Injury, Peter R. Oeltgen, Paul D. Bishop, Mark S. Kindy, Juan A. Sanchez

Molecular and Cellular Biochemistry Faculty Patents

A compound and method for using compound-D SEQ ID NO:1 to reduce injury associated with ischemia and reperfusion of mammalian organs such as the heart. The compound may be administered as part of a preconditioning strategy which reduces the extent of injury and improves organ function following cessation and restoration of blood flow. The compound may be used in preparation for planned ischemia or in a prophylactic manner in anticipation of further ischemic events.

Waddington’S Widget: Hsp90 And The Inheritance Of Acquired Characters, Douglas M. Ruden, Mark D. Garfinkel, Vincent E. Sollars, Xiangyi Lu

Biochemistry and Microbiology

Conrad Waddington published an influential model for evolution in his 1942 paper, Canalization of Development and Inheritance of Acquired Characters. In this classic, albeit controversial, paper, he proposed that an unknown mechanism exists that conceals phenotypic variation until the organism is stressed. Recent studies have proposed that the highly conserved chaperone Hsp90 could function as a “capacitor,” or an “adaptively inducible canalizer,” that masks silent phenotypic variation of either genetic or epigenetic origin. This review will discuss evidence for, and arguments against, the role of Hsp90 as a capacitor for morphological evolution, and as a key component of what …

Topographical Expression Of Class Ia And Class Ii Phosphoinositide 3-Kinase Enzymes In Normal Human Tissues Is Consistent With A Role In Differentiation, Soha Salama El Sheikh, Jan Domin, Prakitpunthu Tomtitchong, Paul Abel, Gordon Stamp, El-Nasir Lalani

Department of Pathology and Laboratory Medicine

Background: Growth factor, cytokine and chemokine-induced activation of PI3K enzymes constitutes the start of a complex signalling cascade, which ultimately mediates cellular activities such as proliferation, differentiation, chemotaxis, survival, trafficking, and glucose homeostasis. The PI3K enzyme family is divided into 3 classes; class I (subdivided into IA and IB), class II (PI3K-C2α, PI3K-C2β and PI3K-C2γ) and class III PI3K. Expression of these enzymes in human tissue has not been clearly defined.

Methods: In this study, we analysed the immunohistochemical topographical expression profile of class IA (anti-p85 adaptor) and class II PI3K (PI3K-C2α and PI3K-C2β) enzymes in 104 formalin-fixed, paraffin embedded …

Computational Models For Diffusion Of Second Messengers In Visual Transduction, Harihar Khanal

Publications

The process of phototransduction, whereby light is converted into an electrical response in retinal rod and cone photoreceptors, involves, as a crucial step, the diffusion of cytoplasmic signaling molecules, termed second messengers. A barrier to mathematical and computational modeling is the complex geometry of the rod outer segment which contains about 1000 thin discs. Most current investigations on the subject assume a well-stirred bulk aqueous environment thereby avoiding such geometrical complexity. We present theoretical and computational spatio-temporal models for phototransduction in vertebrate rod photoreceptors, which are pointwise in nature and thus take into account the complex geometry of the …

Characterization Of Mutations And Loss Of Heterozygosity Of P53 And K-Ras2 In Pancreatic Cancer Cell Lines By Immobilized Polymerase Chain Reaction, James Butz, Eric Wickstrom, Jeremy Edwards

Department of Biochemistry and Molecular Biology Faculty Papers

Background

The identification of known mutations in a cell population is important for clinical applications and basic cancer research. In this work an immobilized form of the polymerase chain reaction, referred to as polony technology, was used to detect mutations as well as gene deletions, resulting in loss of heterozygosity (LOH), in cancer cell lines. Specifically, the mutational hotspots in p53, namely codons 175, 245, 248, 249, 273, and 282, and K-ras2, codons 12, 13 and 61, were genotyped in the pancreatic cell line, Panc-1. In addition LOH analysis was also performed for these same two genes in Panc-1 by …

Vam10p Defines A Sec18p-Independent Step Of Priming That Allows Yeast Vacuole Tethering, Masashi Kato, William Wickner

Dartmouth Scholarship

YOR068c, termed VAM10 (altered vacuole morphology), lies within the VPS5 gene on the opposite DNA strand. VAM10 deletion causes vacuole fragmentation in vivo. The in vitro fusion of purified yeast vacuoles is stimulated by recombinant Vam10p and blocked by antibody to Vam10p. Vam10p acts early in the priming stage of fusion, independent of Sec18p. After priming, recombinant Vam10p will not stimulate fusion and anti-Vam10p antibodies will not inhibit; Vam10p provides a functional marker for this Sec18p-independent priming step. Pure Vam10p restores normal, Ypt7p-dependent tethering to vacuoles from a vam10Δ strain.

Copper Chelation Represses The Vascular Response To Injury, Lazar Mandinov, Anna Mandinova, Stanimir Kyurkchiev, Dobroslav Kyurkchiev, Ivan Kehayov, Vihren Kolev, Raffaella Soldi, Cinzia Bagala, Ebo D. De Muinck, Volkhard Lindner, Mark J. Post, Michael Simons

Dartmouth Scholarship

The induction of an acute inflammatory response followed by the release of polypeptide cytokines and growth factors from peripheral blood monocytes has been implicated in mediating the response to vascular injury. Because the Cu2+-binding proteins IL-1alpha and fibroblast growth factor 1 are exported into the extracellular compartment in a stress-dependent manner by using intracellular Cu2+ to facilitate the formation of S100A13 heterotetrameric complexes and these signal peptideless polypeptides have been implicated as regulators of vascular injury in vivo, we examined the ability of Cu2+ chelation to repress neointimal thickening in response to injury. We observed that the oral administration of …

Rhythmic Binding Of A White Collar-Containing Complex To The Frequency Promoter Is Inhibited By Frequency, Allan C. Froehlich, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

The biological clock of Neurospora crassa includes interconnected transcriptional and translational feedback loops that cause both the transcript and protein encoded by the frequency gene (frq) to undergo the robust daily oscillations in abundance, which are essential for clock function. To understand better the mechanism generating rhythmic frq transcript, reporter constructs were used to show that the oscillation in frq message is transcriptionally regulated, and a single cis-acting element in the frq promoter, the Clock Box (C box), is both necessary and sufficient for this rhythmic transcription. Nuclear protein extracts used in binding assays revealed that a White Collar (WC)-1- …

Mammalian Erv46 Localizes To The Endoplasmic Reticulum–Golgi Intermediate Compartment And To Cis-Golgi Cisternae, Lelio Orci, Mariella Ravazzola, Gary J. Mack, Charles Barlowe, Stefan Otte

Dartmouth Scholarship

Yeast endoplasmic reticulum (ER) vesicle protein Erv46p is a novel membrane protein involved in transport through the early secretory pathway. Investigation of mammalian Erv46 (mErv46) reveals that it is broadly expressed in tissues and protein-secreting cells. By immunofluorescence microscopy, mErv46 displays a crescent-shaped perinuclear staining pattern that is characteristic of the Golgi complex. Quantitative immunoelectron microscopy indicates that mErv46 is restricted to the cis face of the Golgi apparatus and to vesicular tubular structures between the transitional ER and cis-Golgi. Minor amounts of mErv46 reside in ER membranes and later Golgi cisternae. On Brefeldin A treatment, mErv46 redistributes to punctate …

Seventeen Amino Acid Peptide (Peptide P) For Treating Ischemia And Reperfusion Injury, Peter R. Oeltgen, Mark S. Kindy

Molecular and Cellular Biochemistry Faculty Patents

Peptide P, having the amino acid sequence Tyr-D-Ala-Phe-Ala-Asp-Val-Ala-Ser-Thr-Ile-Gly-Asp-Phe-Phe-His-Ser-Ile-NH2, is useful to treat ischemia.

High Dietary Level Of Synthetic Vitamin E On Lipid Peroxidation, Membrane Fatty Acid Composition And Cytotoxicity In Breast Cancer Xenograft And In Mouse Host Tissue, Ivan L. Cameron, Jesus Munoz, Christopher J. Barnes, W. Elaine Hardman

Biochemistry and Microbiology

Background

d-α-tocopherol is a naturally occurring form of vitamin E not previously known to have antitumor activity. Synthetic vitamin E (sE) is a commonly used dietary supplement consisting of a mixture of d-α-tocopherol and 7 equimolar stereoisomers. To test for antilipid peroxidation and for antitumor activity of sE supplementation, two groups of nude mice bearing a MDA-MB 231 human breast cancer tumor were fed an AIN-76 diet, one with and one without an additional 2000 IU/kg dry food (equivalent to 900 mg of all-rac-α-tocopherol or sE). This provided an intake of about 200 mg/kg body weight per day. The mice …

Transfection Of Il-10 Expression Vectors Into Endothelial Cultures Attenuates Alpha4beta7-Dependent Lymphocyte Adhesion Mediated By Madcam-1., Makoto Sasaki, Paul Jordan, Jeff Houghton, Xianmin Meng, Makoto Itoh, Takashi Joh, J Steven Alexander

Department of Dermatology and Cutaneous Biology Faculty Papers

BACKGROUND: Enhanced expression of MAdCAM-1 (mucosal addressin cell adhesion molecule-1) is associated with the onset and progression of inflammatory bowel disease. The clinical significance of elevated MAdCAM-1 expression is supported by studies showing that immunoneutralization of MAdCAM-1, or its ligands reduce inflammation and mucosal damage in models of colitis. Interleukin-10 (IL-10) is an endogenous anti-inflammatory and immunomodulatory cytokine that has been shown to prevent inflammation and injury in several animal studies, however clinical IL-10 treatment remains insufficient because of difficulties in the route of IL-10 administration and its biological half-life. Here, we examined the ability of introducing an IL-10 expression …

The Characterization Of Two Differentially Expressed Plasma Proteins In Obese Versus Lean Rats In Two Rodent Models Of Obesity, Roger D. Boggs

Theses, Dissertations and Capstones

Zucker fa and La/N faf rats are widely studied models of genetic obesity and its complications. These two rodent models of obesity were utilized to search for a circulating protein marker for obesity. Plasma samples from both of these models of obesity were collected and analyzed via SDS-PAGE analysis. Two proteins were found which demonstrate differential expression between lean and obese rats. Both proteins demonstrated increased expression in the obese rats compared to the lean. One differentially expressed protein migrated on SDS-PAGE gels at 116 KD while the second migrated at 22 KD compared to molecular weight markers. The 22 …

A Mechanistic Study In The Nephrotoxicity Of P-Aminophenol, R. Christopher Harmon

Theses, Dissertations and Capstones

The acetaminophen metabolite, p-aminophenol (PAP), is a known nephrotoxicant. The current study is directed at understanding the mechanism of this nephrotoxicity. Renal cortical slices isolated from F344 rats were incubated with 0 – 0.5 mM PAP with or without pretreatments. Renal slices exposed to PAP showed toxicity as measured by increased lactate dehydrogenase leakage (LDH), decreased pyruvate-stimulated gluconeogenesis, and decreased total adenine nucleotides. There was, however, an increase in ATP as percent of total, implying maintained mitochondrial function. These data show that PAP is directly toxic to renal cortical slices. Pretreatment with EDTA or EGTA provided protection from PAP- induced …

The Role Of Oxidative Stress In Alzheimer's Disease, Robin Petroze

Kaleidoscope

Over four million individuals in the United States currently suffer from Alzheimer's disease (AD), a devastating disorder of progressive dementia. Within the next several decades, AD is expected to affect over 22 million people globally. AD can only be definitively diagnosed by postmortem examination. Thus, investigation into the specific pathogenesis of neuronal degeneration and death in AD on a biochemical level is essential for both earlier diagnosis and potential treatment and prevention options. Overproduction of amyloid [3-peptide (A[3) in the brain leads to both free radical oxidative stress and toxicity to neurons in AD. My undergraduate biochemical studies with regard …