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Articles 7201 - 7230 of 7421

Full-Text Articles in Cell and Developmental Biology

Characterization Of Two Temperature-Sensitive Mutants Of Escherichia Coli Exhibiting An Altered L22 Ribosomal Protein, Bonnie A. Burnette-Vick Aug 1991

Characterization Of Two Temperature-Sensitive Mutants Of Escherichia Coli Exhibiting An Altered L22 Ribosomal Protein, Bonnie A. Burnette-Vick

Electronic Theses and Dissertations

Analysis of E. coli strains SK1047 and SK1048 have shown them to be temperature-sensitive, protein-synthesis deficient. An alteration in ribosomal protein L22 was detected in both strains using two dimensional gel electrophoresis. Protein L22 was purified from both strains by reversed phase high performance liquid chromatography and from two dimensional electrophoretic gels. Purified ribosomal protein L22 was labeled by reductive methylation and used in 23S RNA binding assays with and without ribosomal protein L4. At the permissive temperature, protein L22 from SK1047 bound less efficiently than the control while protein L22 from SK1048 bound as efficiently as the control. At …

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The Submembrane Machinery For Nicotinic Acetylcholine Receptor Clustering, S. C. Froehner Jul 1991

The Submembrane Machinery For Nicotinic Acetylcholine Receptor Clustering, S. C. Froehner

Dartmouth Scholarship

No abstract provided.

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Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu May 1991

Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu

Electronic Theses and Dissertations

Tryptase, a mast cell-specific serine protease with trypsin-like specificity, has been identified in a mouse mast cell line (ABFTL-6) based on it's enzymatic activity, inhibition properties, and cross-reactivity to a human mast cell tryptase antibody. The effects of fibroblast-conditioned medium and sodium butyrate on ABFTL-6 mast cell differentiation and tryptase expression have been examined. ABFTL-6 mouse mast cells undergo phenotypic changes upon culturing in media supplemented with fibroblast-conditioned media at 50% or 1 mM sodium butyrate. The induced cells increased in size, had larger and more metachromatic cytoplasmic granules, and increased their total cellular protein about four-fold. Tryptase activity increased …

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Fertilization And Mouse Embryo Development In The Presence Of Midazolam, Maria Leavitt Apr 1991

Fertilization And Mouse Embryo Development In The Presence Of Midazolam, Maria Leavitt

Biological Sciences Theses & Dissertations

The development of mouse embryos in vitro has provided a unique opportunity for the study of cellular differentiation and the influence of various agents on differentiation. Midazolam is administered for conscious sedation in the recovery of human ova. In the Norfolk IVF Program, midazolam is found in varying concentrations in follicular fluid. Mouse embryo formation and development has been used to test midazolam's effect on fertilization and early development as a model of human in vitro fertilization and development. Midazolam' s effects were studied using varying doses of midazolam on (1) in vivo fertilization and subsequent cell division, and (2) …

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Cells That Express All Five Proteins Of Vesicular Stomatitis Virus From Cloned Cdnas Support Replication, Assembly, And Budding Of Defective Interfering Particles, Asit K. Pattnaik, Gail W. Wertz Feb 1991

Cells That Express All Five Proteins Of Vesicular Stomatitis Virus From Cloned Cdnas Support Replication, Assembly, And Budding Of Defective Interfering Particles, Asit K. Pattnaik, Gail W. Wertz

School of Veterinary and Biomedical Sciences: Faculty Publications

An alternative approach to structurefunction analysis of vesicular stomatitis virus (VSV) gene products and their interactions with one another during each phase of the viral life cycle is described. We showed previously by using the vaccinia viruslT7 RNA polymerase expression system that when cells expressing the nucleocapsid protein (N), the phosphoprotein (NS), and the large polymerase protein (L) of VSV were superinfected with defective interfering (DI) particles, rapid and efflicient replication and amplification of DI particle RNA occurred. Here, we demonstrate that all five VSV proteins can be expressed simultaneously when cells are cotransfected with plasmids containing the matrix protein …

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Cloning And Immunogenicity Of A Chlamydia Trachomatis 36 Kilodalton Recombinant Gene Product In Escherichia Coli, Hector Rivera Jan 1991

Cloning And Immunogenicity Of A Chlamydia Trachomatis 36 Kilodalton Recombinant Gene Product In Escherichia Coli, Hector Rivera

Theses Digitization Project

No abstract provided.

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Photoreactivation Of Uv-Induced Damage In G1 Phase Xenopus Cells That Leads To A Sister Chromatid Exchanged And Cell Death, Dawn Laswell, Jennifer Barber, H. Gaston Griggs Jan 1991

Photoreactivation Of Uv-Induced Damage In G1 Phase Xenopus Cells That Leads To A Sister Chromatid Exchanged And Cell Death, Dawn Laswell, Jennifer Barber, H. Gaston Griggs

Journal of the Arkansas Academy of Science

Experiments were conducted with the A87 Xenopus tissue culture cell line which centered on use of the line's efficient photoreactivation (PR) mechanism to: (1) determine the extent to which sister chromatid exchanges (SCEs), induced by exposing early G1 phase cells to low UV fluenced, are photoreactivable, and (2) determine the extent to which the photoreactivable SCEs resulting from these low UV fluences constitute lethal lesions. For the first determination, UV fluences - SCE frequency relations and UV fluence + PR fluence - SCE frequency relations were established for UV fluences in the range 0-12 J/m2 and a single PR fluence …

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Cell Surface-Binding Sites For Progesterone Mediate Calcium Uptake In Human Sperm, Peter F. Blackmore, Joseph Neulan, Frank Lattanzio, Stephen J. Beebe Jan 1991

Cell Surface-Binding Sites For Progesterone Mediate Calcium Uptake In Human Sperm, Peter F. Blackmore, Joseph Neulan, Frank Lattanzio, Stephen J. Beebe

Bioelectrics Publications

Recent studies (e.g. Blackmore, P. F., Beebe, S. J., Danforth, D. R., and Alexander, N.) (1990) J. Biol. Chem. 265, 1376-1380) have shown that in human sperm, progesterone produces a rapid increase in intracellular free calcium ([Ca2+]i) and an induction of the acrosome reaction (e.g. Osman, R. A., Andria, M. L., Jones, A. D., and Meizel, S. (1989) Biochem. Biophys. Res. Commun. 160, 828-833). In this study, the location of progesterone receptors on the cell surface of human sperm was identified using progesterone immobilized on bovine serum albumin (BSA) (progesterone 3-(O-carboxymethyl)oxime:BSA) as well as progesterone and its 3-O-carboxymethyloxime derivative. Using …

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A Role For Fibronectin In The Development Of Beat In Chick Embryo Cardiogenesis, W. Kimryn Rathmell Jan 1991

A Role For Fibronectin In The Development Of Beat In Chick Embryo Cardiogenesis, W. Kimryn Rathmell

Presidential Scholars Theses (1990 – 2006)

Fibronectin is believed to play a directional role in the migration of precardiac mesodermal cells and m~y be involved in other aspects of cardiogenesis. In this study we investigated the role of fibronectin in the development development of heart beat by employing a chick precardiac explant culture system. Fibronectin is recognized by an integrin receptor molecule via an RGD amino acid sequence. Using a synthetic RGD peptide we have blocked the ability of any existing receptor molecules to interact with fibronectin in an attempt to break communication of the mesodermal cells with the extracellular environment. Explanted tissues treated with this …

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Reproductive Performance Of Female White-Tailed Deer On Holla Bend National Wildlife Refuge, Thomas A. Nelson Jan 1991

Reproductive Performance Of Female White-Tailed Deer On Holla Bend National Wildlife Refuge, Thomas A. Nelson

Journal of the Arkansas Academy of Science

Aspects of the reproductive biology of female white-tailed deer (Odocoileus virginianus) on Holla Bend National Wildlife Refuge were investigated by examining the reproductive tracts of 121 deer harvested during the 1985-90 archery seasons. The presence of corpora albicantia in yearlings suggested that 27% of female fawns conceived, producing a mean of 1.0 ova/breeding fawn. Pregnancy rates among yearlings and adults averaged 94% and 97%, respectively. Ovulation rates averaged 1.4 and 2.0 ova/female among yearlings and adults. Some females were ovulating in early-October, but the earliest conceptions occurred during the last week of October. The peak breeding period for yearlings and …

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Monoclonal Antibodies To The Fusion Protein Of Bovine Respiratory Syncytial Virus, Kent M. Mulkey, Gary A. Anderson Jan 1991

Monoclonal Antibodies To The Fusion Protein Of Bovine Respiratory Syncytial Virus, Kent M. Mulkey, Gary A. Anderson

School of Veterinary and Biomedical Sciences: Faculty Publications

Five monoclonal antibodies specific for bovine respiratory syncytial virus were characterized by Western immunoblotting, radioimmunoprecipitation, and epitope mapping assays. The monoclonal antibodies were found to be specific for the fusion protein, and there were at least two antigen binding sites, one of which was neutralizing.

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Evidence For The Elevation Of Serum Carcinoembryonic Antigen And Tumor-Associated Glycoprotein-72 Levels In Patients Administered Interferons, John Greiner, Fiorella Guadagni, David Goldstein, Ernest Borden, Roy Ritts, Patricia Witt, Albert Lobuglio, Mansoor Saleh, Jeffrey Schlom Jan 1991

Evidence For The Elevation Of Serum Carcinoembryonic Antigen And Tumor-Associated Glycoprotein-72 Levels In Patients Administered Interferons, John Greiner, Fiorella Guadagni, David Goldstein, Ernest Borden, Roy Ritts, Patricia Witt, Albert Lobuglio, Mansoor Saleh, Jeffrey Schlom

Haematology and Oncology, East Africa

Sera were collected from 111 patients diagnosed with adenocarcinoma or nonadenocarcinoma malignancies who received different schedules of interferon (IFN)-γ or IFN-βser alone or in combination. Serum carcinoembryonic antigen (CEA) and tumor-associated glycoprotein-72 (TAG-72) antigen levels were measured to determine whether interferon could enhance the tumor shedding and, thereby, the serum level of either tumor antigen. Less than 10% of the sera samples from patients diagnosed with nonadenocarcinoma malignancies (e.g., hairy cell leukemia, melanoma) had positive titers of TAG-72 or CEA, and interferon neither increased nor resulted in the appearance of either tumor antigen in those sera. In contrast, 59.2% and …

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The Effects Of Glutathione On Human Keratinocyte, Manisha N. Trivedi Jan 1991

The Effects Of Glutathione On Human Keratinocyte, Manisha N. Trivedi

Theses and Dissertations in Biomedical Sciences

Cultured human keratinocytes were grown in vitro to assess the effects of glutathione, a thiol, on human keratinocyte proliferation. Single keratinocytes were harvested from newborn (greater than 5 days old) foreskin and were grown in culture flasks such that experiments could be performed in approximately 2 to 3 weeks. In order to evaluate the effects of glutathione (GSH) on keratinocyte growth, experiments were performed to determine the growth curve, plating efficiency, and incorporation of radiolabelled thymidine. Growth studies, performed with different concentrations of glutathione, revealed that 0.065 μM was the most effective concentration when compared to control cell cultures, and …

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Laminin Potentiates Differentiation Of Pcc4uva Embryonal Carcinoma Into Neurons, T. M. Sweeney, Roy C. Ogle, C. D. Little Sep 1990

Laminin Potentiates Differentiation Of Pcc4uva Embryonal Carcinoma Into Neurons, T. M. Sweeney, Roy C. Ogle, C. D. Little

School of Medical Diagnostics & Translational Sciences Publications

The embryonal carcinoma PCC4uva differentiates into neurons in response to treatment with retinoic acid and dbcAMP. We used this in vitro model system to study the effects of laminin on early neural differentiation. Laminin substrata markedly potentiate neural differentiation of retinoic acid and dbcAMP-treated cultures. Only laminin induced more rapid neural cell body clustering, neurite growth and neurite fasciculation as compared to type IV collagen, type I collagen, and fibronectin substrata. Exogenous laminin substrata promoted greater cell attachment, cellular spreading and growth to confluence than type IV collagen, type I collagen, fibronectin and glass substrata. Laminin-induced effects were inhibited by …

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Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss Aug 1990

Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss

Electronic Theses and Dissertations

The electrophysiologic technique (Reuss, L., Proc. Natl. Acad. Sci. USA 82:6014, 1985) was modified to measure changes in steady-state hepatocyte volume during osmotic stress. Hepatocytes in mouse liver slices were loaded with tetramethylammonium ion (TMA$\sp{+}$) during transient exposure of cells to nystatin. Intracellular TMA$\sp{+}$ activity (a$\sp{\rm i}\sb{\rm TMA}$) was measured with TMA$\sp{+}$-sensitive, double-barreled microelectrodes. Loading hepatocytes with TMA$\sp{+}$ did not change their membrane potential (V$\sb{\rm m}$), and under steady-state conditions a$\sp{\rm i}\sb{\rm TMA}$ remained constant over 4 min in single impalements. Hyperosmotic solutions (50, 100, & 150 mM sucrose added to media) and hyposmotic solutions (sucrose in media reduced by …

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Effects Of Chemical Aneuploidogens On Taxol Purified Drosophila And Mouse Brain Microtubules Polymerization And Depolymerization In Vitro, Anil Sehgal Jul 1990

Effects Of Chemical Aneuploidogens On Taxol Purified Drosophila And Mouse Brain Microtubules Polymerization And Depolymerization In Vitro, Anil Sehgal

Biological Sciences Theses & Dissertations

The effects of aneuploidogens (aneuploidy causing agents) on taxol-purified microtubules from Drosophila and mouse brain in vitro were studied by using a spectrophotometric assay and electron microscopy. Colchicine, acetonitrile, propionitrile, acrylonitrile, dimethyl sulfoxide (DMSO), griseofulvin and cadmium chloride inhibited microtubule polymerization whereas methoxyethyl acetate (MEA) and methyl mercuric chloride (MMC) did not. All aneuploidogens tested (at 50mM) resulted in reduced rate of elongation of mouse brain microtubules. MMC, cadmium chloride and DMSO resulted in increased rates of Drosophila microtubule elongation whereas the rest of the drugs resulted in decreases. The in vitro results from Drosophila correlate well with the previously …

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Evidence Of A Neurogenic Component During Ige-Mediated Inflammation In Murine Skin, Victoria Jean Cavanaugh Jul 1990

Evidence Of A Neurogenic Component During Ige-Mediated Inflammation In Murine Skin, Victoria Jean Cavanaugh

Biological Sciences Theses & Dissertations

The direct stimulation of sensory nerves or the intradermal injection of neuropeptides triggers a cutaneous inflammatory response that involves the degranulation of mast cells. These neurogenic inflammatory reactions are physiologically similar to IgE-mediated hypersensitivity responses, which also depend on mast cells. Although non-antigenic stimuli distinguish neurogenic from IgE-mediated inflammation, the similarity of their effector stages suggested that peripheral nerves may also participate in lgE-mediated responses. To examine this hypothesis, IgE responses were elicited in denervated skin. A murine model was developed where the footpad was denervated by surgically removing a 2 mm segment of the sciatic nerve, proximal to the …

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Replication And Amplification Of Defective Interfering Particle Rn As Of Vesicular Stomatitis Virus In Cells Expressing Viral Proteins From Vectors Containing Cloned Cdnas, Asit K. Pattnaik, Gail W. Wertz Jun 1990

Replication And Amplification Of Defective Interfering Particle Rn As Of Vesicular Stomatitis Virus In Cells Expressing Viral Proteins From Vectors Containing Cloned Cdnas, Asit K. Pattnaik, Gail W. Wertz

School of Veterinary and Biomedical Sciences: Faculty Publications

Replication and amplification of RNA genomes of defective interfering (DI) particles of vesicular stomatitis virus (VSV) depend on the expression of viral proteins and have untD now been attained only in ceUs coinfected with helper VSV. In the work described in this report, we used a recombinant vaccinia virus-T7 RNA polymerase expression system to synthesize individual VSV proteins in cells transfected with plasmid DNAs that contain cDNA copies of the VSV genes downstream of the T7 RNA polymerase promoter. In this way, we were able to examine the ability of VSV proteins, individually and in combination, to support DI particle …

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N-Ethylmaleimide-Sensitive Protein(S) Involved In Cortical Exocytosis In The Sea-Urchin Egg - Localization To Both Cortical Vesicles And Plasma-Membrane, Robert C. Jackson, Paul A. Modern Mar 1990

N-Ethylmaleimide-Sensitive Protein(S) Involved In Cortical Exocytosis In The Sea-Urchin Egg - Localization To Both Cortical Vesicles And Plasma-Membrane, Robert C. Jackson, Paul A. Modern

Dartmouth Scholarship

The exocytotic release of secretory products from fragments of sea urchin egg cortex has been shown to be inhibited by covalent modification of membrane sulfhydryl groups with N-ethylmaleimide (NEM). Exocytotically competent preparations of reconstituted cortex, formed by recombination of purified cortical vesicles (CVs) with fragments of egg plasma membrane (PM) were also inhibited by treatment with NEM. The cellular localization of sulfhydryl-containing constituent(s) responsible for inhibition was investigated by treating CVs and/or PM with NEM prior to reconstitution. Both native cortex and cortex reconstituted with NEM-treated components were challenged with calcium-containing buffers. Exocytosis was monitored by phase-contrast microscopy, and quantitated …

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A Retinoic Acid Responsive Gene, Mk, Produces A Secreted Protein A With Heparin Binding Activity, Masaru Nakamoto Jan 1990

A Retinoic Acid Responsive Gene, Mk, Produces A Secreted Protein A With Heparin Binding Activity, Masaru Nakamoto

Biology Faculty Publications

MK is a gene whose expression increases transiently during retinoic acid-induced differentiation of embryonal carcinoma cells. MK polypeptide was secreted by differentiating HM-1 embryonal carcinoma cells and by L-cells transfected with an MK cDNA under the control of the S-actin promoter and Rous sarcoma virus enhancer. MK polypeptide was found to have heparin binding activity. Conditioned medium of the transfected L-cells promoted growth of PC-12 pheochromocytoma cells. These findings support the view that MK polypeptide is a secreted factor involved in regulation of growth and differentiation.

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Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander Jan 1990

Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander

Bioelectrics Publications

Progesterone and 17 alpha-hydroxyprogesterone (but not other steroids such as testosterone, corticosterone, beta-estradiol, estrone, dehydroepiandrosterone, 20 alpha-hydroxypregnen-3-one, androstenedione, and pregnenolone) were shown to cause an immediate increase, in free cytosolic calcium ([Ca2+]i) in both capacitated and noncapacitated human sperm, using the fluorescent indicator fura 2. Significant increases in [Ca2+]i were observed with 10 ng/ml progesterone, while maximum effects were seen with 1 microgram/ml progesterone. Two other steroids 11 beta-hydroxyprogesterone and 5 alpha-pregnane-3,20-dione exhibited significant activity to increase [Ca2+]i. This increase in [Ca2+]i elicited by progesterone was entirely due to Ca2+ influx from the extracellular medium since the increase in [Ca2+]i …

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Time Course Of Photoreactivation Of Uv Induced Damage In G1 Phase Xenopus Cells That Leads To Chromosome Breaks Observable By Premature Chromosome Condensation, Robert Wright, Stephen Ruble, H. Gaston Griggs Jan 1990

Time Course Of Photoreactivation Of Uv Induced Damage In G1 Phase Xenopus Cells That Leads To Chromosome Breaks Observable By Premature Chromosome Condensation, Robert Wright, Stephen Ruble, H. Gaston Griggs

Journal of the Arkansas Academy of Science

No abstract provided.

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The Status Of The Fetus In Mosaic Law, Ron Du Preez Jan 1990

The Status Of The Fetus In Mosaic Law, Ron Du Preez

Journal of the Adventist Theological Society

No abstract provided.

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Efficacy Of A Cell Extract From Actinobacillus (Haemophilus) Pleuropneumoniae Serotype 1 Against Disease In Swine, P. J. Fedorka-Cray, M.J. Huether, D.L. Stine, G. A. Anderson Jan 1990

Efficacy Of A Cell Extract From Actinobacillus (Haemophilus) Pleuropneumoniae Serotype 1 Against Disease In Swine, P. J. Fedorka-Cray, M.J. Huether, D.L. Stine, G. A. Anderson

School of Veterinary and Biomedical Sciences: Faculty Publications

We partially characterized a cell extract (CE) from Actinobacillus pleuropneumoniae serotype 1 and used the CE to test the efficacy of secreted proteins against disease. Secreted products from 4-h culture supernatants were precipitated with 20% polyethylene glycol. Analysis of the CE indicated the presence of protein, endotoxin, and carbohydrate. Hemolytic activity to bovine erythrocytes and cytotoxic activity to porcine mononuclear leukocytes was also demonstrated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the CE from a 4-h culture showed a major band at 110 kilodaltons (kDa), while a CE of a 26-h culture indicated the presence of a number of additional …

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The Role Of Small Peptides In Cancer Physiology And Chemotherapy, Bao-Ling Tsay Jan 1990

The Role Of Small Peptides In Cancer Physiology And Chemotherapy, Bao-Ling Tsay

Theses and Dissertations in Biomedical Sciences

The targeting of proven anticancer drugs specifically to cancer cells would provide a unique opportunity to restrict neoplasms without damaging the cancer patient. The present research utilizes the phenomenon of illicit transport, i.e. the coupling of normally impermeant metabolites to permeant metabolites, in targeting the drug melphalan to mouse Ehrlich ascites tumor cells. The dipeptide beta-alanyl-melphalan was synthesized and tested in vitro for toxicity towards mouse Ehrlich ascites tumor cells, mouse liver cells, and mouse 3T3 embryonic cells. The parent compound, melphalan, was used as a control treatment. In addition, both melphalan and beta-alanyl-melphalan were utilized in in vivo chemotherapeutic …

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Embryonic Chicken Fibroblast Collagen Binding Proteins: Distribution, Role In Substratum Adhesion, And Relationship To Integrins, Roy C. Ogle, A. Jeannette Potts, Marchall Yacoe, Charles D. Little Oct 1989

Embryonic Chicken Fibroblast Collagen Binding Proteins: Distribution, Role In Substratum Adhesion, And Relationship To Integrins, Roy C. Ogle, A. Jeannette Potts, Marchall Yacoe, Charles D. Little

School of Medical Diagnostics & Translational Sciences Publications

Collagen binding proteins (CBP) are hydrophobic, cell surface polypeptides, isolated by collagen affinity chromatography. Antibodies to CBPs inhibit the attachment of embryonic chicken heart fibroblasts to native type I collagen fibrils in a dose-dependent manner. The CBP antibodies also induce rounding and detachment of cells adherent to a planar substratum. This process of antibody-mediated substratum detachment resulted in a clustering of CBP and cell-associated extracellular matrix at the cell surface, and the rearrangement of filamentous actin. Other functional studies showed that cells grown within a three-dimensional gel of type I collagen cannot be immunostained at the cell surface with CBP …

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Immunosuppressive Activity Derived From The Uc729-6 Lymphoblastoid And M21-Hpb Melanoma Cell Lines, Charlene J. Repique Aug 1989

Immunosuppressive Activity Derived From The Uc729-6 Lymphoblastoid And M21-Hpb Melanoma Cell Lines, Charlene J. Repique

Loma Linda University Electronic Theses, Dissertations & Projects

Previous work conducted in our laboratories, using a murine model, suggested that soluble factors secreted by tumor cells suppress lymphocyte responses. To apply this premise to human tumors, we studied the effects of UC729-6 (lymphoblastoid B-cell) and M21-HPB (malignant melanoma) conditioned media (CM) on lymphocyte proliferation assays, as well as on the growth of other cells. The CM was collected at 2-5 day intervals from cultures of UC729-6 and M21- HPB cells in serum-free media. In assays using phytohemagglutinin (PHA) and concanavalin A (ConA), mononuclear peripheral blood cells from healthy human donors showed decreased [3H]-thymidine ([3H]-Tdr) …

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Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure Aug 1989

Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure

Loma Linda University Electronic Theses, Dissertations & Projects

The best understood functional activity of the pineal gland is its diurnal production of melatonin in response to environmental lighting cues. Several enzymes of the melatonin pathway respond to daily photoperiod changes, for example hydroxyindole-O-methyltransferase (HIOMT) and serotonin N-acetyltransferase (SNAT). Increased levels of the glycolytic enzyme neuron-specific enolase (NSE) are thought to reflect increased physiological demands placed on neurons and neuroendocrine tissues. Homodimer non-neuronal enolase isoenzyme (NNE) is immunolocalized to cells, and the hybrid enolase (consisting of subunits from NSE and NNE) has been seen in cerebellar stellate and basket cells. Although not rate limiting, concentrations of both NSE and …

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Collagen Binding Proteins Derived From The Embryonic Fibroblast Cell Surface Recognize Arginine-Glycine-Aspartic Acid, Roy C. Ogle, Charles D. Little Jun 1989

Collagen Binding Proteins Derived From The Embryonic Fibroblast Cell Surface Recognize Arginine-Glycine-Aspartic Acid, Roy C. Ogle, Charles D. Little

School of Medical Diagnostics & Translational Sciences Publications

Several cell surface proteins (Mr = 120,000, 90,000, 63,000 and 47,000) apparently integral to embryonic fibroblast plasma membranes were extracted with detergent and isolated by collagen affinity chromatography. Certain of these proteins (Mr = 120,000, 90,000, and 47,000) were specifically eluted from collagen affinity columns by synthetic peptides containing the amino acid sequence arginyl-glycyl-aspartic acid (RGD). These data show that a number of collagen binding proteins exist on the embryonic fibroblast cell surface. Some of the proteins may be collagen receptors binding to RGD sequences in the collagen molecule while at least one of the proteins (Mr = 63,000) recognizes …

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Hypoxanthine-Induced Differentiation Of Cultured Human Leukemia Cells, Gayle Jennette Singleton Apr 1989

Hypoxanthine-Induced Differentiation Of Cultured Human Leukemia Cells, Gayle Jennette Singleton

Chemistry & Biochemistry Theses & Dissertations

Human cultured leukemia cells appear to have a decreased amount of inosine in their tRNA. When cells with inosine deficient tRNA are placed in a hypoxanthine fortified media, they incorporate hypoxanthine into their tRNA by the action of the enzyme tRNA-hypoxanthine ribosyl transferase. This generates the nucleoside inosine in the tRNA. The cultured human leukemia cell lines, CCRF-CEM, HL-60, and HGPRT(-) HL- 60, incorporate hypoxanthine into their tRNA, as determined by tRNA isolation, hydrolysis, and HPLC analysis. Hypoxanthine treatment dramatically inhibited cell growth in conjunction with partial induction of differentiation in the CCRF-CEM, HL-60, and HGPRT ( - ) HL-60 …

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