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1996

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Articles 1 - 30 of 30

Full-Text Articles in Cell Biology

Numa Assembles Into An Extensive Filamentous Structure When Expressed In The Cell Cytoplasm, Alejandro Saredi, Louisa Howard, Duane A. Compton Nov 1996

Numa Assembles Into An Extensive Filamentous Structure When Expressed In The Cell Cytoplasm, Alejandro Saredi, Louisa Howard, Duane A. Compton

Open Dartmouth: Faculty Open Access Scholarship

NuMA is a 236 kDa protein that participates in the organization of the mitotic spindle despite its strict localization in the nucleus during interphase. To test how cells progress through mitosis when NuMA is localized in the cytoplasm instead of the nucleus, we have deleted the nuclear localization sequence of NuMA using site-directed mutagenesis and transiently expressed this mutant protein (NuMA-DeltaNLS) in BHK-21 cells. During interphase, NuMA-DeltaNLS accumulates in the cytoplasm as a large mass approximately the same size as the cell nucleus. When cells enter mitosis, NuMA-DeltaNLS associates normally with the mitotic spindle without causing any apparent deleterious effects ...


Localization Of Hiv-1 Rna In Mammalian Nuclei, Guohong Zhang, Maria L. Zapp, Guochen Yan, Michael R. Green Oct 1996

Localization Of Hiv-1 Rna In Mammalian Nuclei, Guohong Zhang, Maria L. Zapp, Guochen Yan, Michael R. Green

Open Access Articles

The Rev protein of human immunodeficiency virus type 1 (HIV-1) facilitates the nuclear export of unspliced and partially spliced viral RNAs. In the absence of Rev, these intron-containing HIV-1 RNAs are retained in the nucleus. The basis for nuclear retention is unclear and is an important aspect of Rev regulation. Here we use in situ hybridization and digital imaging microscopy to examine the intranuclear distributions of intron-containing HIV RNAs and to determine their spatial relationships to intranuclear structures. HeLa cells were transfected with an HIV-1 expression vector, and viral transcripts were localized using oligonucleotide probes specific for the unspliced or ...


The Epidermis Still In Control?, Winfried Peters, A. Tomos Aug 1996

The Epidermis Still In Control?, Winfried Peters, A. Tomos

Winfried S. Peters

This paper has no abstract; these are the first two paragraphs. The search for a molecular mechanism of auxin action has rendered the “Auxin-Binding-Protein 1” (ABP-1) the top candidate for a functional auxin receptor (Venis and Napier, 1995), although its status remains disputed (Jones, 1994; Hertel, 1995; Napier, 1995; Venis, 1995). ABP-1 had long been thought to be localized exclusively in epidermal cells in coleoptiles (Löbler and Klämbt, 1985), and thus had fitted nicely the “epidermal-growth-control-hypothesis” (Kutschera, 1987, 1992). The recent report from the same lab of its uniform distribution throughout the coleoptile (Kayser and Klämbt, 1995) not only rises ...


Distribution Of Poly(Adp-Ribose) Glycohydrolase In Different Functional Domains Of The Cell Nucleus, Gustavo Pacheco-Rodriguez B.S., M.S. Aug 1996

Distribution Of Poly(Adp-Ribose) Glycohydrolase In Different Functional Domains Of The Cell Nucleus, Gustavo Pacheco-Rodriguez B.S., M.S.

Theses and Dissertations

Pacheco-Rodriguez, Gustavo, Distribution of Poly(ADP-ribose) Glycohydrolase in Different Functional Domains of the Cell Nucleus. Doctor of Philosophy (Biomedical Sciences), August, 1996, 147 pp, 3 tables, 44 illustrations, bibliography, 138 titles. In this study, the distributor poly(ADP-ribose) glycohydrolase (PARG) in different subdomains of the cell nucleus and the role of non-covalent interactions of poly(ADP-ribose) with nuclear proteins have been characterized. An assay that allows the simultaneous determination of specific non-covalent interactions of poly (ADP-ribose) with nuclear proteins as well as PARG activity by high resolution polyacrylamide gel electrophoresis was developed. This method was made possible by the enzymatic ...


Myosin Filament Structure In Vertebrate Smooth Muscle, Jun-Qing Xu, Beatrice A. Harder, Pedro Uman, Roger W. Craig Jul 1996

Myosin Filament Structure In Vertebrate Smooth Muscle, Jun-Qing Xu, Beatrice A. Harder, Pedro Uman, Roger W. Craig

Open Access Articles

The in vivo structure of the myosin filaments in vertebrate smooth muscle is unknown. Evidence from purified smooth muscle myosin and from some studies of intact smooth muscle suggests that they may have a nonhelical, side-polar arrangement of crossbridges. However, the bipolar, helical structure characteristic of myosin filaments in striated muscle has not been disproved for smooth muscle. We have used EM to investigate this question in a functionally diverse group of smooth muscles (from the vascular, gastrointestinal, reproductive, and visual systems) from mammalian, amphibian, and avian species. Intact muscle under physiological conditions, rapidly frozen and then freeze substituted, shows ...


Functional Mapping Of The Translation-Dependent Instability Element Of Yeast Matalpha1 Mrna, Aidan N. Hennigan, Allan Jacobson Jul 1996

Functional Mapping Of The Translation-Dependent Instability Element Of Yeast Matalpha1 Mrna, Aidan N. Hennigan, Allan Jacobson

Open Access Articles

The determinants of mRNA stability include specific cis-acting destabilizing sequences located within mRNA coding and noncoding regions. We have developed an approach for mapping coding-region instability sequences in unstable yeast mRNAs that exploits the link between mRNA translation and turnover and the dependence of nonsense-mediated mRNA decay on the activity of the UPF1 gene product. This approach, which involves the systematic insertion of in-frame translational termination codons into the coding sequence of a gene of interest in a upf1delta strain, differs significantly from conventional methods for mapping cis-acting elements in that it causes minimal perturbations to overall mRNA structure. Using ...


The History Of Tissue Tension, Winfried S. Peters, A. Deri Tomos Jun 1996

The History Of Tissue Tension, Winfried S. Peters, A. Deri Tomos

Winfried S. Peters

In recent years the phenomenon of tissue tension and its functional connection to elongation growth has regained much interest. In the present study we reconstruct older models of mechanical inhomogenities in growing plant organs, in order to establish an accurate historical background for the current discussion. We focus on the iatromechanic model developed in Stephen Hales' Vegetable Staticks, Wilhelm Hofmeister's mechanical model of negative geotropism, Julius Sachs' explanation of the development of tissue tension, and the differential-auxin-response-hypothesis by Kenneth Thimann and Charles Schneider. Each of these models is considered in the context of its respective historic and theoretical environment ...


Reversal Of Cell Fate Determination In Caenorhabditis Elegans Vulval Development, Susan Euling, Victor Ambros Apr 1996

Reversal Of Cell Fate Determination In Caenorhabditis Elegans Vulval Development, Susan Euling, Victor Ambros

Open Dartmouth: Faculty Open Access Scholarship

In Caenorhabditis elegans, the fates of the multipotent vulval precursor cells (VPCs) are specified by intercellular signals, The VPCs divide in the third larval stage (L3) of the wild type, producing progeny of determined cell types, In lin-28 mutants, vulva development is similar to wild-type vulva development except that it occurs precociously, in the second larval stage (L2), Consequently, when lin-28 hermaphrodites temporarily arrest development at the end of L2 in the dauer larva stage, these otherwise determined VPC progeny become reprogrammed back to the multipotent, signal- sensitive state of VPCs. Our results indicate that VPC fate determination by intercellular ...


Mitochondrial Dna Of The Thatching Ant, Formica Obscuripes, Gregory Park Apr 1996

Mitochondrial Dna Of The Thatching Ant, Formica Obscuripes, Gregory Park

Life and Environmental Sciences Undergraduate Theses

In a continuing attempt to purify mitochondrial DNA from the thatching ant, modifications were made to a previously developed extraction procedure. Although mitochondria were highly enriched in a subcellular fraction derived from the heads of the ants, when DNA purified from the fraction by an alkaline lysis procedure was electrophoresed, inconsistent results were obtained. Bands in the gel show a molecule larger than 22 kilobase pairs, which is not expected of mtDNA.


A Comparative Study Of The Binding Of Two Lectins In The Early Development Of The Freshwater Sponge, Ephydatia Mulleri, Jay Taylor Apr 1996

A Comparative Study Of The Binding Of Two Lectins In The Early Development Of The Freshwater Sponge, Ephydatia Mulleri, Jay Taylor

Life and Environmental Sciences Undergraduate Theses

Carbohydrates have been implicated in cell adhesion and in developmental processes. Lectin histochemistry using ConcanavalinA and Lotus lectin was used to localize lectin-accessible mannosyl and fucosyl residues in a maturing sponge developing from histoblasts generated during germination of a gemmule. With the exception of cystencytes found in the sponges stained with Lotus lectin, a similar staining pattern was seen with the two lectins, but there was a rather significant difference in the intensity of staining. This difference in staining intensity was thought to be a result of either more mannosyl residues available to the lectin or that the concentration of ...


Preliminary Attempts To Purify Genomic And Mitochondrial Dna From A Freshwater Sponge, Derek Gordon Apr 1996

Preliminary Attempts To Purify Genomic And Mitochondrial Dna From A Freshwater Sponge, Derek Gordon

Life and Environmental Sciences Undergraduate Theses

This project was intended to be a pair of preliminary experiments from which more detailed and specific experiments could be expanded. There were two procedures used in carrying out this study involving the isolation of DNA from a freshwater sponge. First, genomic DNA was isolated and purified. This genomic DNA was digested with the restriction endonuclease EcoR1 and then analyzed using agarose gel electrophoresis. The results showed an accumulation of the sponge DNA in one major band roughly slightly larger than the 21226 bp band generated by EcoR1 digestion of X-phage DNA. The second part of this experiment was an ...


Xist Rna Paints The Inactive X Chromosome At Interphase: Evidence For A Novel Rna Involved In Nuclear/Chromosome Structure, Christine Moulton Clemson, John A. Mcneil, Huntington F. Willard, Jeanne B. Lawrence Feb 1996

Xist Rna Paints The Inactive X Chromosome At Interphase: Evidence For A Novel Rna Involved In Nuclear/Chromosome Structure, Christine Moulton Clemson, John A. Mcneil, Huntington F. Willard, Jeanne B. Lawrence

GSBS Student Publications

The XIST gene is implicated in X chromosome inactivation, yet the RNA contains no apparent open reading frame. An accumulation of XIST RNA is observed near its site of transcription, the inactive X chromosome (Xi). A series of molecular cytogenetic studies comparing properties of XIST RNA to other protein coding RNAs, support a critical distinction for XIST RNA; XIST does not concentrate at Xi simply because it is transcribed and processed there. Most notably, morphometric and 3-D analysis reveals that XIST RNA and Xi are coincident in 2- and 3-D space; hence, the XIST RNA essentially paints Xi. Several results ...


A Novel, Mitogen-Activated Nuclear Kinase Is Related To A Drosophila Developmental Regulator, Gerald V. Denis, Michael R. Green Feb 1996

A Novel, Mitogen-Activated Nuclear Kinase Is Related To A Drosophila Developmental Regulator, Gerald V. Denis, Michael R. Green

Open Access Articles

Although the ultimate targets of many signal transduction pathways are nuclear transcription factors, the vast majority of known protein kinases are cytosolic. Here, we report on a novel human kinase that is present exclusively in the nucleus. Kinase activity is increased upon cellular proliferation and is markedly elevated in patients with acute and chronic lymphocytic leukemias. We have identified a human gene that encodes this nuclear kinase and find that it is closely related to Drosophila female sterile homeotic (fsh), a developmental regulator with no known biochemical activity. Collectively, these results suggest that this nuclear kinase is a component of ...


Heat Shock Factor Gains Access To The Yeast Hsc82 Promoter Independently Of Other Sequence-Specific Factors And Antagonizes Nucleosomal Repression Of Basal And Induced Transcription, Alexander M. Erkine, C. C. Adams, T. Diken, D. S. Gross Jan 1996

Heat Shock Factor Gains Access To The Yeast Hsc82 Promoter Independently Of Other Sequence-Specific Factors And Antagonizes Nucleosomal Repression Of Basal And Induced Transcription, Alexander M. Erkine, C. C. Adams, T. Diken, D. S. Gross

Scholarship and Professional Work – COPHS

Transcription in eukaryotic cells occurs in the context of chromatin. Binding of sequence-specific regulatory factors must contend with the presence of nucleosomes for establishment of a committed preinitiation complex. Here we demonstrate that the high-affinity binding site for heat shock transcription factor (HSF) is occupied independently of other cis-regulatory elements and is critically required for preventing nucleosomal assembly over the yeast HSC82 core promoter under both noninducing (basal) and inducing conditions. Chromosomal mutation of this sequence, termed HSE1, erases the HSF footprint and abolishes both transcription and in vivo occupancy of the TATA box. Moreover, it dramatically reduces promoter chromatin ...


Examination Of The Cell Wall Of Micrasterias Radiosa Var Radiosa (Conjugatophyceae) By Transmission And Scanning Electron Microscopy, Jennifer A. Akin, Richard L. Meyer Jan 1996

Examination Of The Cell Wall Of Micrasterias Radiosa Var Radiosa (Conjugatophyceae) By Transmission And Scanning Electron Microscopy, Jennifer A. Akin, Richard L. Meyer

Journal of the Arkansas Academy of Science

The cell wall of Micrasterias radiosa var. radiosa Ralfs 1848 (Conjugatophyceae) was examined by transmission and scanning electron microscopy. Previous electron microscopy of this taxon has not been performed; thus these are new observations. The cell wall was recognized to be of the Cosmarium type with complex pores external to the plasma membrane that penetrate the secondary wall and with ornamentation arising from the secondary wall. Subdivided regions of the pore apparatus, the pore head, pore bulb, connecting pore channel, and pore depression were detected. Pores of type 4 were located in the isthmal region and at the division of ...


Genetic Analysis Of Rhinichthys Atratulus (Pisces: Cyprinidae) In North Central West Virginia, Alan Harper Tennant Jan 1996

Genetic Analysis Of Rhinichthys Atratulus (Pisces: Cyprinidae) In North Central West Virginia, Alan Harper Tennant

Theses, Dissertations and Capstones

The blacknose dace, Rhinichthys atratulus, is a cyprinid minnow common to shallow streams throughout North America. It has been shown to be sensitive to anthropogenic stress and a study of the genetic nature of R. atratulus populations may yield information about their habitats. In West Virginia, two subspecies of R. atratulus are present, R. a. atratulus and R. a. obtusus, which are separated by the Allegheny divide. In north central West Virginia, R. a. atratulus was observed in the Cheat River drainage, an area previously thought be within the range of R. a. obtusus. Fish of the R. a. atratulus ...


Reconstruction Of Ribosomal Subunits And Rdna Chromatin Imaged By Scanning Force Microscopy, Wolfgang Fritzsche, Linda Martin, Drena Dobbs, Daniel Jondle, Richard Miller, James Vesenka, Eric Henderson Jan 1996

Reconstruction Of Ribosomal Subunits And Rdna Chromatin Imaged By Scanning Force Microscopy, Wolfgang Fritzsche, Linda Martin, Drena Dobbs, Daniel Jondle, Richard Miller, James Vesenka, Eric Henderson

Zoology and Genetics Publications

Scanning force microscopy (SFM) reveals surface topography by scanning a sharp tip in close proximity to the sample. Due to tip–sample interaction, artificial broadening of the real surface structure with the tip geometry occurs. One approach for image reconstruction is the use of calibration standards, preferably in the size range of the samples. In the present study, an image reconstruction method based on colloidal gold as a geometric standard was used to reconstruct SFM images of biomolecules. Sample and calibration standard size were in the nanometer range, and the standards were coadsorbed with the specimen. Raw and reconstructed images ...


Ultrastructural Characterization Of Colloidal Metal Films For Bioanalytical Applications By Scanning Force Microscopy, Wolfgang Fritzsche, Konstantin Sokolov, George D. Chumanov, Therese M. Cotton, Eric Henderson Jan 1996

Ultrastructural Characterization Of Colloidal Metal Films For Bioanalytical Applications By Scanning Force Microscopy, Wolfgang Fritzsche, Konstantin Sokolov, George D. Chumanov, Therese M. Cotton, Eric Henderson

Zoology and Genetics Publications

Colloidal metal films (CMFs) are prepared by the attachment of silver, gold, or platinum (or other metal) particles to a glass slide modified by silanization with 3‐mercaptopropyl silane. The covalent attachment of the metal particles occurs through the metal–sulfur bond. In these samples the local electromagnetic field is enhanced near the surface of the CMF due to excitation of plasmon resonances. This phenomenon can be used for a variety of analytical applications. Because the optical properties are strongly dependent on the morphology of the film, its structural characterization becomes of great importance. To further characterize CMFs we have ...


Regulation Of Dna Replication In Xenopus Laevis , Jing Fang Jan 1996

Regulation Of Dna Replication In Xenopus Laevis , Jing Fang

Retrospective Theses and Dissertations

The purpose of my research project is to make an attempt to understand some aspects of eukaryotic DNA replication by studying how this process is regulated positively or negatively in different physiological conditions. Using Xenopus egg extracts as the in vitro replication system, I studied the inhibitors of DNA replication found in nuclei of Xenopus quiescent cells. Replication of nuclei isolated from quiescent Xenopus cells was barely detectable in interphase extracts of Xenopus laevis eggs, although Xenopus sperm chromatin was replicated with about 100% efficiency in the same extracts. The evidence of the inhibitors came further from the fact that ...


Modulation Of Queuine Uptake And Incorporation Into Trna By Protein Kinase C And Protein Phosphatase, Rana C. Morris, Bonnie J. Brooks, K. Lenore Hart, Mark S. Elliot Jan 1996

Modulation Of Queuine Uptake And Incorporation Into Trna By Protein Kinase C And Protein Phosphatase, Rana C. Morris, Bonnie J. Brooks, K. Lenore Hart, Mark S. Elliot

Chemistry & Biochemistry Faculty Publications

It has been suggested that the rate of queuine uptake into cultured human fibroblasts is controlled by phosphorylation levels within the cell. We show that the uptake of queuine is stimulated by activators of protein kinase C (PKC) and inhibitors of protein phosphatase; while inhibitors of PKC, and down-regulation of PKC by chronic exposure to phorbol esters inhibit the uptake of queuine into cultured human fibroblasts. Activators of cAMP- and cGMP-dependent kinases exert no effect on the uptake of queuine into fibroblast cell cultures. These studies suggest that PKC directly supports the activity of the queuine uptake mechanism, and that ...


Identification Of Mouse Sip24/24p3 As A New Acute Phase Protein And Study Of Its Expression , Quansheng Liu Jan 1996

Identification Of Mouse Sip24/24p3 As A New Acute Phase Protein And Study Of Its Expression , Quansheng Liu

Retrospective Theses and Dissertations

Mouse SIP24 was originally discovered as a 24 k Da inducible protein secreted from quiescent Balb/c 3T3 fibroblast cells. Based on the analysis of peptide sequencing results and Western blot studies, SIP24 was identified as identical to the mouse protein encoded by 24P3 and is thus referred to as SIP24/24P3 in this thesis. SIP24/24P3 is a member of the lipocalin protein family, and its human homolog NGAL (neutrophil gelatinase associated lipocalin) has been reported to bind the chemotactic factor, fMLP (N-formylmethionyl-leucyl-phenylalanine);Studies were carried out to test the hypothesis that SIP24/24P3 is an acute phase protein ...


The Role Of Rat Brain Ptp-1 Surface Basic Residues In Substrate Reactivity , Deborah Sue Baedke Jan 1996

The Role Of Rat Brain Ptp-1 Surface Basic Residues In Substrate Reactivity , Deborah Sue Baedke

Retrospective Theses and Dissertations

Previous work by others has demonstrated that rat brain protein tyrosine phosphatase (rbPTP-1) exhibited increased reactivity toward substrates containing acidic residues N-terminal to phosphotyrosine. We show that substrates containing a single acidic residue C-terminal to the phosphotyrosine also enhanced reactivity with rbPTP-1. A substrate aspartate residue at the P+2 position exhibited the greatest enhancement of reactivity;Surface basic residues of rbPTP-1 were investigated for their role in the increased reactivity due to substrate acidic residues. Mutation of R47 or K120 to alanine decreased the enhancement of reactivity due to acidic residues N-terminal to phosphotyrosine by 78% and 73% respectively ...


Mechanisms Of Arginine Vasopressin-Induced Insulin Secretion In Rinm5f Cells , Ter-Hsin Chen Jan 1996

Mechanisms Of Arginine Vasopressin-Induced Insulin Secretion In Rinm5f Cells , Ter-Hsin Chen

Retrospective Theses and Dissertations

The present study was to investigate the mechanism by which AVP increases insulin secretion in RINm5F cells. A specific PLC inhibitor, U-73122, and a PLA2 inhibitor, N-(p-amylcinnamoyl)anthranilic acid (ACA) were used. U-73122 (2-8 [mu]M) inhibited the AVP-induced increases in the intracellular concentration of inositol 1,3,4-trisphosphate and (Ca2+]i dose-dependently. U-73122 (8 [mu]M) abolished the AVP's effect on IP3 and (Ca2+]i, but it only reduced the AVP-induced increase in insulin secretion by 35%. The discrepancy between the results of (Ca2+]i and insulin secretion may be due to the multiple signal transduction pathways ...


Utilization Of Fatigued And Non-Fatigued Isolated Guinea-Pig Papillary Muscles And Ventricular Myocytes On The Comparison Of Inotropic, Chronotropic And Intracellular Calcium Changes Induced By Monensin And Digoxin , Ismail Meral Jan 1996

Utilization Of Fatigued And Non-Fatigued Isolated Guinea-Pig Papillary Muscles And Ventricular Myocytes On The Comparison Of Inotropic, Chronotropic And Intracellular Calcium Changes Induced By Monensin And Digoxin , Ismail Meral

Retrospective Theses and Dissertations

Experiment 1. We investigated the effects of monensin and digoxin on contraction force (CF), initial contraction velocity (ICV), average contraction velocity (ACV), initial relaxation velocity (IRV) and stimulus to response time (ST) change in fatigued (defined as the level at which papillary muscle contraction had lost 30% of its original contraction force with the elapse of time) and non-fatigued guinea-pig papillary muscles. The five hours of measurement in Experiment 3 were divided into five periods (T0 was equilibration, T1, T2, T3, and T4 were respectively one, two, three, and four hours after drug administration). We found that both monensin and ...


Porcine Reproductive And Respiratory Syndrome Virus Infection Of Cells: Characterization Of The Early Stages Of Virus Infection And The Major Structural Proteins Of The Virus , Luiz Carlos Kreutz Jan 1996

Porcine Reproductive And Respiratory Syndrome Virus Infection Of Cells: Characterization Of The Early Stages Of Virus Infection And The Major Structural Proteins Of The Virus , Luiz Carlos Kreutz

Retrospective Theses and Dissertations

Porcine reproductive and respiratory syndrome (PRRS) is one of the major causes of economic losses to swine producers. The causative agent, the PRRS virus (PRRSV), has been tentatively classified as an arterivirus. PRRSV infect swine alveolar macrophages and induce persistent infection. In vitro, PRRSV replication is restricted to few continuous cell lines, none of which of porcine origin. The interaction of PRRSV with cells and the major structural proteins of the virus have been investigated in these studies, aiming to better understand the mechanisms governing cell tropism and replication in cells;Several cells were used to determine the mechanism of ...


Astrocyte Volume Regulation , Trent Allan Basarsky Jan 1996

Astrocyte Volume Regulation , Trent Allan Basarsky

Retrospective Theses and Dissertations

This dissertation deals with the regulation of synapse formation between cultured hippocampal neurons, and the volume dynamics of astrocytes during hyposmotic-induced swelling;The developmental time course of synapse formation in cultured hippocampal neurons was examined. After 12 days in culture (DIC) inhibitory and excitatory synapses formed which were sensitive to the N-type calcium channel antagonist [omega]-conotoxin GVIA ([omega]-CgTx) while, at 4 DIC, immature connections were present in which spontaneous, but rarely evoked, synaptic currents were detected. A comparison of 4 and 12 DIC neurons revealed the presence of the synaptic proteins rab3a, synapsin I, and synaptotagmin, but the ...


Single Cell Analysis By Capillary Electrophoresis With Laser-Induced Native Fluorescence Detection , Sheri Joanne Lillard Jan 1996

Single Cell Analysis By Capillary Electrophoresis With Laser-Induced Native Fluorescence Detection , Sheri Joanne Lillard

Retrospective Theses and Dissertations

Individual mammalian cells were analyzed by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). This technique was chosen due to its high separation efficiencies, small sample volumes and sensitive detection. Native fluorescence was used, in which the analyte was not tagged with a fluorophore. 275-nm excitation gave attomole (amol = 10-18 mol) detection limits for the intracellular species of interest. Two projects are described in which hemoglobin (Hb) variants were determined in single red blood cells. In the third experiment, individual mast cells were degranulated on-column, and exocytosis and serotonin release were monitored temporally;First, single red blood cells, in which Hb ...


Purification, Characterization And Molecular Cloning Of Muscle Paranemin , Philip Mark Hemken Jan 1996

Purification, Characterization And Molecular Cloning Of Muscle Paranemin , Philip Mark Hemken

Retrospective Theses and Dissertations

Paranemin is an incompletely characterized ~280 kilodalton protein previously identified and immunolocalized in embryonic chick skeletal muscle. Paranemin has been purified from the same tissue source, has the same molecular weight by SDS-PAGE, and has the same antibody localization at the Z-lines of adult avian cardiac muscle. The method developed for preparation of purified paranemin from embryonic (chick) skeletal muscle includes homogenization, centrifugation and gel filtration, hydroxyapatite, and DEAE-cellulose chromatography. By using this method, ~2 mg of purified paranemin was routinely obtained. Amino acid analysis revealed that paranemin has a high acidic to basic amino acid ratio, which agrees with ...


Cloning Of Bovine Intercellular Adhesion Molecules And Characterization Of Expression Of Neutrophil Adhesion Molecules In Periparturient Cows And Calves , Eunkyung Lee Jan 1996

Cloning Of Bovine Intercellular Adhesion Molecules And Characterization Of Expression Of Neutrophil Adhesion Molecules In Periparturient Cows And Calves , Eunkyung Lee

Retrospective Theses and Dissertations

The interactions of circulating leukocytes with the endothelium represent a key point in the effector functions of the immune system by regulating the specificity and strength of cell-cell interactions. The recruitment of neutrophils to sites of inflammation is initiated by chemoattractants. The initial contact of neutrophils on vascular endothelial cells is a rolling interaction mediated by members of the selectin family. These include E-selectin and P-selectin on the surface of activated endothelial cells, and L-selectin on neutrophils. The subsequent activation of leukocyte [beta]2 integrins, which bind to the glycoprotein intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, is essential for ...


Review: To Bud Until Death: The Genetics Of Aging In The Yeast, Saccharomyces, Father Nicanor Austriaco Dec 1995

Review: To Bud Until Death: The Genetics Of Aging In The Yeast, Saccharomyces, Father Nicanor Austriaco

Rev. Nicanor Austriaco, O.P.

Individual cells of the budding yeast, Saccharomyces cerevisiae, have a limited division capacity and undergo characteristicchanges as they senesce, primarily increasing both their cell size and cell cycle time. The mortality curve for ageing yeast cells can be described by the Gompertz equation, the classical definition for an ageing population. Recent work from several laboratories has demonstrated that genes can determine the yeast lifespan. Studies with the UTH genes have implicated changes in transcriptional silencing during yeast ageing, but the roles of the RAS2, LAG1 and PHBl genes in regulating yeast longevity are still unclear. What is becoming clearer, however ...