Medicine and Health Sciences Commons^™

Mitotic Spindle Poles Are Organized By Structural And Motor Proteins In Addition To Centrosomes, Tirso Gaglio, Mary A. Dionne, Duane A. Duane A. Compton

Dartmouth Scholarship

The focusing of microtubules into mitotic spindle poles in vertebrate somatic cells has been assumed to be the consequence of their nucleation from centrosomes. Contrary to this simple view, in this article we show that an antibody recognizing the light intermediate chain of cytoplasmic dynein (70.1) disrupts both the focused organization of microtubule minus ends and the localization of the nuclear mitotic apparatus protein at spindle poles when injected into cultured cells during metaphase, despite the presence of centrosomes. Examination of the effects of this dynein-specific antibody both in vitro using a cell-free system for mitotic aster assembly and in …

The Type 2 Iodothyronine Deiodinase Is Expressed Primarily In Glial Cells In The Neonatal Rat Brain, Ana Guadaño-Ferraz, Maria Jesus Obregón, Donald L. St. Germain, Juan Bernal

Dartmouth Scholarship

Thyroid hormone plays an essential role in mammalian brain maturation and function, in large part by regulating the expression of specific neuronal genes. In this tissue, the type 2 deiodinase (D2) appears to be essential for providing adequate levels of the active thyroid hormone 3,5,3′-triiodothyronine (T3) during the developmental period. We have studied the regional and cellular localization of D2 mRNA in the brain of 15-day-old neonatal rats. D2 is expressed in the cerebral cortex, olfactory bulb, hippocampus, caudate, thalamus, hypothalamus, and cerebellum and was absent from the white matter. At the cellular level, D2 is expressed predominantly, if not …

Sqt1, Which Encodes An Essential Wd Domain Protein Of Saccharomyces Cerevisiae, Suppresses Dominant-Negative Mutations Of The Ribosomal Protein Gene Qsr1., Dominic P. Eisinger, Frederick A. Dick, Elke Denke, Bernard L. Trumpower

Dartmouth Scholarship

QSR1 is an essential Saccharomyces cerevisiae gene, which encodes a 60S ribosomal subunit protein required for joining of 40S and 60S subunits. Truncations of QSR1 predicted to encode C-terminally truncated forms of Qsr1p do not substitute for QSR1 but do act as dominant negative mutations, inhibiting the growth of yeast when expressed from an inducible promoter. The dominant negative mutants exhibit a polysome profile characterized by 'half-mer' polysomes, indicative of a subunit joining defect like that seen in other qsr1 mutants (D. P. Eisinger, F. A. Dick, and B. L. Trumpower, Mol. Cell. Biol. 17:5136-5145, 1997.) By screening a high-copy …

Increased Focal Adhesion Kinase- And Urokinase-Type Plasminogen Activator Receptor-Associated Cell Signaling In Endothelial Cells Exposed To Asbestos, A Barchowsky, B M. Lannon, L C. Elmore, M D. Treadwell

Dartmouth Scholarship

Exposure of low-passage endothelial cells in culture to nonlethal amounts of asbestos, but not refractory ceramic fiber-1, increases cell motility and gene expression. These changes may be initiated by the fibers mimicking matrix proteins as ligands for receptors on the cell surface. In the present study, 1- to 3-hr exposures of endothelial cells to 5 mg/cm2 of chrysotile asbestos caused marked cell elongation and motility. However, little morphological change was seen when chrysotile was added to cells pretreated with either mannosamine to prevent assembly of glycophosphatidylinositol (GPI)-anchored receptors or with herbimycin A to inhibit tyrosine kinase activity. Affinity purification of …

Qsr1p, A 60s Ribosomal Subunit Protein, Is Required For Joining Of 40s And 60s Subunits., Dominic P. Eisinger, Frederick A. Dick, Bernard L. Trumpower

Dartmouth Scholarship

QSR1 is a recently discovered, essential Saccharomyces cerevisiae gene, which encodes a 60S ribosomal subunit protein. Thirty-one unique temperature-sensitive alleles of QSR1 were generated by regional codon randomization within a conserved 20-amino-acid sequence of the QSR1-encoded protein. The temperature-sensitive mutants arrest as viable, large, unbudded cells 24 to 48 h after a shift to 37 degrees C. Polysome and ribosomal subunit analysis by velocity gradient centrifugation of lysates from temperature-sensitive qsr1 mutants and from cells in which Qsr1p was depleted by down regulation of an inducible promoter revealed the presence of half-mer polysomes and a large pool of free 60S …

Identification Of A Gal/Galnac Lectin In The Protozoan Hartmannella Vermiformis As A Potential Receptor For Attachment And Invasion By The Legionnaires' Disease Bacterium, Chandrasekar Venkataraman, Bradley J. Haack, Subbarao Bondada, Yousef Abu Kwaik

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Legionnaire's disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen which invades and replicates within two evolutionarily distant hosts, free-living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaire's disease. Although attachment and invasion of human macrophages by L. pneumophila is mediated in part by the complement receptors CR1 and CR3, the protozoan receptor involved in bacterial attachment and invasion has not been identified. To define the molecular events involved in invasion of protozoa by L. pneumophila, we examined the role of protein tyrosine phosphorylation …

The Beneficial Effect Of Vitamin E And Selenium During Experimental Chagas' Disease, Yue Hou

Masters Theses & Specialist Projects

The present study was conducted to determine if vitamin E and selenium could have a positive synergistic effect during experimental Chagas' disease. In the first phase of the study, 25 female C3HeB/FeJ mice were infected with a Brazil strain of Trypanosoma cruzi while receiving vitamin E supplementation of 0 IU/kg, 200 IU/kg, 400 IU/kg, 600 IU/kg, 800 IU/kg in their diets. In the second phase, 20 female C3HeB/FeJ mice were infected while receiving 400 IU/kg vitamin E plus selenium supplementation of 2 ppm, 4 ppm, 8 ppm, 16 ppm in their drinking water. The results demonstrate that vitamin E does …

The Clastogenic Effects Of Cyclophosphamide And A Sixty Hertz Electromagnetic Field On Bone Marrow Cells Of Cd-1 Mice, Kevin K. Block

Dissertations

Extremely low frequency (ELF) electromagnetic fields (EMF) have been correlated with the induction of cancer in a number of epidemiological studies (Feychting and Ahlbom, 1993; T,m and Lee, 1994; London e t al. 1991; Lovely et al., 1994; Tomenius, 1986; Wertheimer and Leeper, 1979, 1982). Two hypothesis were tested in the present study. The first hypothesis tested was that exposure to a 7.3 G magnetic field for 24 hours would increase the frequency of clastogenic and/or mutagenic events in bone m arrow cells of mice. The second hypothesis tested was that exposure to a 7.3 G magnetic field for 24 …

Assembly And Regulation Of The Cd40 Receptor Complex In Human B Cells, Michelle R. Kuhné, Michael Robbins, John E. Hambor, Matthew F. Mackey, Yoko Kosaka, Toshihide Nishimura, Jason P. Gigley, Randolph J. Noelle, David M. Calderhead

Dartmouth Scholarship

CD40 is a member of the tumor necrosis factor (TNF) receptor superfamily. Studies with human B cells show that the binding of CD154 (gp39, CD40L) to CD40 recruits TNF receptor– associated factor 2 (TRAF2) and TRAF3 to the receptor complex, induces the downregulation of the nonreceptor-associated TRAFs in the cell and induces an increased expression of Fas on the cell surface. Combined signaling through the interluekin 4 receptor and CD40 induces an increased expression of Fas with a commensurate increase in the level of TRAF2, but not TRAF3, that is recruited to the receptor complex. In contrast, engagement of the …

Hybrid Vector And Method Resulting In Protein Overproduction By Eukaryotic Cells, Robert E. Rhoads, Arrico De Benedetti

Molecular and Cellular Biochemistry Faculty Patents

A hybrid vector carrying a first and second DNA segments operationally linked thereto, the first DNA segment encoding a protein capable of cross-linking to the cap structure of mRNA and mediating ribosome-binding, and the second DNA segment encoding a polypeptide or protein, the vector being capable of replication, transcription and translation to express the factor and the polypeptide or protein upon transformation of a eukaryotic host, and the polypeptide or protein being expressed at a level higher than the level of expression thereof in the absence of the first DNA segment. A eukaryotic host is transformed with this hybrid vector. …

Analysis Of Enhancer Function Of The Hs-40 Core Sequence Of The Human Alpha-Globin Cluster, Hsiaoli Chen, Christopher H. Lowrey, George Stamatoyannopoulos

Dartmouth Scholarship

HS-40 is the major regulatory element of the human α-globin locus, located 40 kb upstream of the ζ-globin gene. To test for potential interactions between HS-40 and the β- or the γ-globin gene promoters in stable transfection assays, the HS-40 core sequence was cloned upstream of either the β promoter or the γ promoter driving the neomycin phosphotransferase gene and enhancer activity was measured using a colony assay. In K562 or in MEL cells, enhancer activity of HS-40 was higher than that of the individual core sequences of the DNase I hypersensitive sites (HS) of the β-globin locus control region …

Transcranial Magnetic Stimulation Of The Prefrontal Cortex Delays Contralateral Endogenous Saccades, Tony Ro, Avishai Henik, Liana Machado, Robert D. Rafal

Publications and Research

The contributions of the superior prefrontal cortex (SPFC) and the superior parietal lobule (SPL) in generating voluntary endogenous and reflexive visually guided saccades were investigated using transcranial magnetic stimulation (TMS). Subjects made choice saccades to the left or right visual field in response to a central arrowhead (endogenous go signal) or a peripheral asterisk (exogenous go signal) that were presented along with a single TMS pulse at varying temporal intervals. TMS over the SPFC increased latencies for saccades made in response to an endogenous go signal toward the contralateral hemifield. No effects were observed when the go signal was exogenous …

Regulation Of The Rat Liver Sodium-Dependent Bile Acid Cotransporter Gene By Prolactin. Mediation Of Transcriptional Activation By Stat5, Tanmoy C. Ganguly, Michelle L. O'Brien, Saul J. Karpen, James F. Hyde, Fredrick J. Suchy, Mary Vore

Toxicology and Cancer Biology Faculty Publications

The intracellular mechanism(s) underlying the upregulation of the hepatic Na+/taurocholate cotransporting polypeptide (ntcp) by prolactin (PRL) are unknown. In this report, we demonstrate a time-dependent increase in nuclear translocation of phosphorylated liver Stat5 (a member of the ignal ransducers and ctivators of ranscription family) that correlated with suckling-induced increases in serum PRL levels. In electrophoretic mobility gel shift assays, nuclear Stat5 exhibited specific DNA-binding ability towards IFN-gamma-activated sequence (GAS)-like elements (GLEs; 5'TTC/A-PyNPu-G/TAA-3') located in the -937 to -904 bp region of the ntcp promoter. Transient cotransfections in HepG2 cells revealed that PRL inducibility (2.5-3-fold) required coexpression of the long form …

The Glucose Transporter Glut4 And The Aminopeptidase Vp165 Colocalise In Tubulo-Vesicular Elements In Adipocytes And Cardiomyocytes, Sally Martin, Jacqueline E. Rice, Gwyn W. Gould, Susanna R. Keller

Dartmouth Scholarship

The aminopeptidase vp165 is one of the major polypeptides enriched in GLUT4-containing vesicles immuno-isolated from adipocytes. In the present study we have confirmed and quantified the high degree of colocalisation between GLUT4 and vp165 using double label immuno-electron microscopy on vesicles isolated from adipocytes and heart. The percentage of vp165-containing vesicles that also contained GLUT4 was 91%, 76%, and 86% in rat adipocytes, 3T3-L1 adipocytes, and rat heart, respectively. Internalisation of a transferrin/HRP (Tf/HRP) conjugate by 3T3-L1 adipocytes, followed by diaminobenzidine treatment in intact cells, resulted in ablation of only 41% and 45% of GLUT4 and vp165, respectively, whereas endosomal …

Cellular Responses In Escherichia Coli To Lethal And Sublethal Doses Of Ozone, Indira Ruth Komanapalli

Loma Linda University Electronic Theses, Dissertations & Projects

Ozone is a major component of photochemical smog. High levels of this pollutant, sufficient to affect human health are found in many urban areas worldwide. Though limited studies in humans are supported by extensive findings from animal experiments, a difficulty in interpreting the results of these experiments has lead to an ambiguity on the biochemical mechanism of ozone toxicity. To elucidate the mechanism by which ozone causes cell damage and eventual cell death we conducted a comprehensive study using Escherichia coli K-12 as a model.

Studies on the comparative inactivation of bacteriophage lambda (λ), Escherichia coli, and Candida albicans …

Reference Serum Chemistry And Hematological Values For Spinal Cord Injured Patients, Michael S. Laymon, Antone L. Davis Ii

Loma Linda University Electronic Theses, Dissertations & Projects

Serum chemistry and hematological values from 220 traumatic spinal cord injured patients (157 male and 63 female between the ages of 15-47, with greater than six months from injury) were compiled via chart review. Traumatic spinal cord injured patient’s reference ranges were determined and compared with the general population reference ranges. Reference ranges within the spinal cord population were compared by age, gender, level of injury and chronicity of injury. The reference ranges determined for all groups within this spinal cord population fall within the reference ranges of the general population. This supports recent research which suggests that a decrease …

Effect Of Long-Term Hypoxia On Myocardial Alpha1- Receptors, Bihong T. Chen

Loma Linda University Electronic Theses, Dissertations & Projects

To determine the developmental changes in myocardial α₁-adrenergic receptor system, we employed [³H-Prazosin] binding technique to characterize α₁-adrenergic receptors in both fetal and adult sheep myocardial ventricular membrane preparations. Myocardial α₁-adrenergic receptor density (Bmax) declined during developmental process with both fetal left ventricle(LV) and fetal right ventricle(RV) having significantly more binding sites than respective adult ventricles. We also demonstrated that the positive inotropic response to the α₁-adrenergic agonist phenylephrine did not differ significantly between the fetal and adult ventricles.

The present study also investigated the effect of long-term high-altitude hypoxemia …

Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole

Dartmouth Scholarship

The ability of DNA tumor virus proteins to trigger apoptosis in mammalian cells is well established. For example, transgenic expression of a simian virus 40 (SV40) T-antigen N-terminal fragment (N-termTag) is known to induce apoptosis in choroid plexus epithelial cells. SV40 T-antigen-induced apoptosis has generally been considered to be a p53-dependent event because cell death in the brain is greatly diminished in a p53-/- background strain and is abrogated by expression of wild-type (p53-binding) SV40 T antigen. We now show that while N-termTags triggered apoptosis in rat embryo fibroblasts cultured in low serum, expression of full-length T antigens unable to …

Distribution Of Endosomal, Lysosomal And Mhc Markers In A Monocytic Cell Line Infected With Chlamydia Psittaci, David M. Ojcius, Raymond Hellio, Alice Dautry-Varsat

All Dugoni School of Dentistry Faculty Articles

The intracellular fate of Chlamydia psittaci during infection of a monocytic cell line, THP1, was characterized. Cytochalasin D inhibited phagocytosis of latex beads but had no effect on infection by C. psittaci, and vacuoles expressed the transferrin receptor, suggesting accessibility to the endocytic pathway. Early Chlamydia-containing vacuoles expressed major histocompatibility complex (MHC) class I molecules, and most vacuoles fused with host cell lysosomes, since they expressed LAMP-1 and had acidic pHs. In cells prestimulated with gamma interferon, vacuoles also expressed MHC class II molecules, suggesting that the monocytes might effectively process Chlamydia-derived antigens for presentation by MHC class I and …

Molecular And Cellular Biology Of Prostate Cancer, El-Nasir Lalani, Marc Elie Laniado, Paul David Abel

Department of Pathology and Laboratory Medicine

Prostate cancer is an enigmatic disease. Although prostatic-intraepithelial neoplasia appears as early as the third decade and as many as 80% of 80 year old men have epithelial cells in their prostate that fit the morphological criteria for cancer, only about 10% of men will ever have the clinical disease and less than 3% will die from it. There have been no significant proven interventions which have altered the natural history of the disease since hormone down regulation was introduced in the 1940s and new research has been poorly supported. There is however an urgent need to develop new criteria …

Hallucinations, Peter J. Whitehouse, Marian B. Patterson, Milton E. Strauss, David S. Geldmacher, James L. Mack, Grover C. Gilmore, Elizabeth Koss

Faculty Scholarship

No abstract provided.

Dna-Protein Cross-Linking By Pyrrolizidine Alkaloids, Gail L. Drew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pyrrolizidine alkaloids (PAs) are natural plant compounds found in hundreds of plant species worldwide and are reported to have cytotoxic, carcinogenic, antimitotic, and genotoxic activity. PAs are metabolized by the cytochrome P450 (CYP) system to the pyrrole or the N-oxide form. The pyrroles are bifunctional electrophilic alkylators that bind cellular nucleophiles such as DNA and proteins and sirupt normal cell processes, including DNA replication and gene transcription and can cause megalocytosis. The pyrroles dehydrosenecionine (DHSN) and dehydromonocrotaline (DHMO) are among the most potent PA cross-linkers and inducers of megalocytosis. DHSN and DHMO-induced cross-links in cultured normal (MDBK) and neoplastic (MCF7) …

Aflatoxin B1 Metabolism In Mammalian Pulmonary Tissue, J. Michael Eichelberger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin B₁ (AFB₁) is a potent dietary hepatocarcinogen and may be a lung carcinogen when inhaled. To study the relative ability of lung and liver to metabolize AFB₁, a susceptible (Swiss-Webster rat) and resistant species (Syrian golden hamster) were pretreated with inducing agents in order to identify specific AFB₁ metabolizing enzymes in each tissue.

Analysis of AFB₁-exo-epoxide (AFBO) formation, O-dealkynation assays, and protein immunoblots demonstrated that cytochrome P450 (CYP) 1A proteins were overexpressed in both the lung and liver of hamsters pretreated with 3-methylchyolanthrene (3-MC). Only CYP1A1 was expressed in the lung …

Spin Trapping Pharmaceutical Compositions And Methods For Use Thereof, John M. Carney, Robert A. Floyd

Pharmacology and Nutritional Sciences Faculty Patents

Spin trapping compositions in general have now been discovered to be effective in treating a variety of disorders, including disorders such as those arising from ischemia, infection, inflammation, exposure to radiation or cytotoxic compounds, not just of the central and peripheral nervous systems but of peripheral organ disease having a wide variety of etiologies. In the preferred embodiment, the compositions for treating tissue damage from ischemia contain PBN, or active derivatives thereof, in a suitable pharmaceutical carrier for intravenous, oral, topical, or nasal/pulmonary administration. Many different disorders can be treated using these compounds, including diseases or disorders of the central …

The Influence Of Low Dietary Fat Intake On Incidence And Severity Of Migraine Headache, Zuzana Bic

Loma Linda University Electronic Theses, Dissertations & Projects

Migraine headaches are a common and debilitating syndrome causing untold suffering and loss of productivity. A review of the literature indicates that there are two primary factors involved in triggering these headaches: high levels of blood lipids and high levels of free fatty acids. Under these conditions platelet aggregability is increased, which is associated with decreases in serotonin and heightened prostaglandins levels. These conditions may produce vasodilation, the most immediate precursor to migraine headache. A high fat diet is one factor that may directly affect this process. This study was undertaken to evaluate the impact of dietary fat intake on …

Dissection Of A Circadian Oscillation Into Discrete Domains, Martha W. Merrow, Norman Y. Garceau, Jay C. Dunlap

Dartmouth Scholarship

The circadian oscillator in Neurospora is a negative feedback loop involving as principal players the products of the frequency (frq) locus. frq encodes multiple forms of its protein product FRQ, which act to depress the amounts of frq transcript. In this scheme there are two discrete and separable steps to the circadian cycle, negative feedback itself (repression) in which FRQ acts to decrease the levels of its own transcript, and recovery from repression (derepression) in which frq transcript levels return to peak amounts. By introducing an exogenously regulatable frq transgene into a frq loss-of-function strain (frq^{9 …}

Anti-Idiotype Monoclonal Antibody 1a7 And Use For The Treatment Of Melanoma And Small Cell Carcinoma, Malaya Chatterjee, Kenneth A. Foon

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention relates isolation of anti-idiotypic antibody 1A7 raised against anti-GD2 mAb 14G2a and its use for the treatment of melanoma and small cell carcinoma. The antibody may be used as a substitute for isolated purified GD2 antigen in any appropriate application.

Update - March 1997, Loma Linda University Center For Christian Bioethics

Update

In this issue:

-- James Walters publishes book on Personhood
-- Prayer and Health Care: An "Altared" Responsibility
-- Conference Report on "Bioethics and Human Destiny: Jewish and Christian Perspectives"

Drift Macroalgal Abundance In Seagrass Beds: Investigating Large-Scale Associations With Physical And Biotic Attributes, Susan S. Bell, Margaret O. Hall

Integrative Biology Faculty and Staff Publications

The relationship between a suite of physical and biological factors and drift macroalgal abundance was examined in 12 seagrass sites spanning a distance of over 50 km within Tampa Bay, Florida, USA. Field sampling was conducted in December 1991, and drift algal abundance was determined by recording algal percent cover from 25 quadrants at each site. Additionally, drift macroalgae were collected from gridded plots and dry weight biomass measured. Sediment characteristics and seagrass biomass, shoot density, blade length and percent cover at each site were also determined. Likewise, position of site within Tampa Bay was categorized by spatial coordinates. Step-wise …

Transgenic Mice Which Overexpress Nerve Growth Factor, Kathryn M. Albers, Brian M. Davis

Neuroscience Faculty Patents

Transgenic mice that express increased levels of nerve growth factor (NGF) in the epidermis and other stratified, keratinized epithelium. The nerve growth factor expressing transgenic mice are useful in the study of neurodegenerative disorders of the brain such as Parkinson's syndrome and Alzheimer's disease and for testing for drug candidates for the treatment of these diseases.