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Articles 13111 - 13140 of 13694

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Adsorption To Dipalmitoylphosphatidylcholine Membranes In Gel And Fluid State: Pentachlorophenolate, Dipicrylamine, And Tetraphenylborate, Pavel Smejtek, S. R. Wang Nov 1990

Adsorption To Dipalmitoylphosphatidylcholine Membranes In Gel And Fluid State: Pentachlorophenolate, Dipicrylamine, And Tetraphenylborate, Pavel Smejtek, S. R. Wang

Physics Faculty Publications and Presentations

We measured the dependence of electrophoretic mobility of dipalmitoylphosphatidylcholine (DPPC) vesicles on the aqueous concentration of negatively charged ions of pentachlorophenol (PCP), dipicrylamine (DPA), and tetraphenylborate (TPhB). The objective was to determine how the physical state of hydrocarbon chains of lipids affects adsorption of lipophilic ions. The studies were done at 25 and 42 degrees C to determine adsorption properties of DPPC membrane in the gel and fluid state, respectively. From the analysis of zeta-potential isotherms in terms of Langmuir-Stern-Grahame model we obtained the association constant, K, the area of the adsorption site, Ps, and the linear partition coefficient, beta. …


Mega Doses Of Methotrexate In The Treatment Of Osteosarcoma, M P. Iqbal, I A. Malik Oct 1990

Mega Doses Of Methotrexate In The Treatment Of Osteosarcoma, M P. Iqbal, I A. Malik

Department of Biological & Biomedical Sciences

Abstract is not provided by the author/publisher


Activation In Vitro Of Transfer Rna-Guanine Ribosyltransferase By Protein Kinase C, Panayota Eriotou Oct 1990

Activation In Vitro Of Transfer Rna-Guanine Ribosyltransferase By Protein Kinase C, Panayota Eriotou

Chemistry & Biochemistry Theses & Dissertations

The purpose of this study was to isolate and purify the enzymes, transfer RNA-guanine ribosyltrasferase and protein kinase C, and to determine whether the phosphorylating enzyme activates the insertion enzyme in vitro. Transfer RNA-guanine ribosyltransferase lost activity within several days after isolation and total, complete reactivation was accomplished in the presence of protein kinase C. This demonstrated that ribosyltransferase's instability is related to the degree of its phosphorylation. It is proposed that modification of tRNA is controlled by protein kinase C. Deactivation of the insertion enzyme leads to hypomodified tRNA which in turn is associated with neoplasia. Potential use …


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 …


Highway Deicing Salts And The Mobilization Of Selected Heavy Metals From Stream Sediments, Harlie David Cole Aug 1990

Highway Deicing Salts And The Mobilization Of Selected Heavy Metals From Stream Sediments, Harlie David Cole

Dissertations

This study was undertaken to: (a) determine the effect of sodium chloride concentration on mobilizing cadmium, copper, lead, nickel, and zinc from stream sediments; (b) determine if chloro-metal complexes may play a role in any such mobilization; and (c) determine the correlations between chloride ion and each of these metals in an urban stream during winter road-salting periods.

The drainage basin of the Red Run, an urban stream draining all or parts of several cities north of Detroit, Michigan, was chosen as a study site. Stream sediments containing the five heavy metals were stirred with sodium chloride or sodium nitrate …


Kinematic Considerations Of Elite Alpine Slalom Ski Racers, David Andrew Goodwin Aug 1990

Kinematic Considerations Of Elite Alpine Slalom Ski Racers, David Andrew Goodwin

Masters Theses

This study described specific kinematic parameters associated with success on the international level in alpine slalom ski racing. Sixteen male athletes representing twelve countries comprised the subject pool. Subject selection was based on finish position in the men's special slalom at the 1989 World Alpine Ski Championships in Vail, Colorado. Cinematographical records were analyzed by a method known as direct linear transformation.

The findings of the study indicated that: (a) hip and knee joint angles of the turning leg must approximate 1.80 to 1.83 radians and 1.82 to 2.21 radians, respectively, for efficiency in this turn; (b) a decrease in …


The Use Of Synthetic Oligodeoxyribonucleotides In Direct Analysis Of Single Nucleotide Variations And Inhibition Of Eukaryotic Gene Expression, Daniel Y. Wu Aug 1990

The Use Of Synthetic Oligodeoxyribonucleotides In Direct Analysis Of Single Nucleotide Variations And Inhibition Of Eukaryotic Gene Expression, Daniel Y. Wu

Loma Linda University Electronic Theses, Dissertations & Projects

The present thesis work contributes to two areas of molecular genetics, namely the development of methods for identifying single nucleotides and the understanding of the mechanism by which antisense oligonucleotides inhibit eukaryotic gene expression. Three single nucleotide detection methods are presented. The first method utilizes hybridization with synthetic oligonucleotide probes to detect single or multiple nucleotide differences between alleles in genomic DNA without electrophoretic separation. Total genomic DNA (either digested or undigested with restriction endonucleases) was immobilized in depressions in an agarose gel (in situ dots) and hybridized with radiolabeled, allele-specific oligonucleotide probes. We show that this method can be …


Development Of Catalytic Rnas As Potential Anti-Hiv-1 Agents, Pairoj Sae Chang Aug 1990

Development Of Catalytic Rnas As Potential Anti-Hiv-1 Agents, Pairoj Sae Chang

Loma Linda University Electronic Theses, Dissertations & Projects

RNA molecules with enzymatic activity (ribozymes) targeted to the genome of HIV-1 were developed and demonstrated to mediate site-specific cleavage of the HIV-1 RNA in vitro and to inhibit viral proliferation intracellularly. Two classes of ribozymes that incorporate a "hammerhead" catalytic center were utilized, eotide elements in the viral sequence to provide half of the The first class used nuclcatalytic center. A complementary strand harboring the remaining active site nucleotides was supplied in trans and directed the site-specific cleavage of the HIV-1 RNA target. A second type of ribozyme incorporated the entire catalytic center, minus the site of cleavage, within …


Proto-Oncogene Regulation By Growth Factors In Bone Cells, Harold Lyndon Merriman Aug 1990

Proto-Oncogene Regulation By Growth Factors In Bone Cells, Harold Lyndon Merriman

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have shown that bone cells in culture produce a number of growth factors that are important in bone regulation. Chick and mouse primary calvarial cultures consist of a mixture of cell types that make it difficult to interpret the results from these model systems. In contrast, MC3T3-E1 cells are a clonal mouse osteoblast-like cell line. Since MC3T3-E1 cells consist of a single population of calvarial cells, they make an ideal system in which to study the autocrine effects of bone growth factors.

Based on this work, MC3T3-E1 cells are now known to produce IGF-I, TGF-beta and IGF-II in …


K-Casein And Its Interaction In Human Milk Micelles, Barbara C. Dev Aug 1990

K-Casein And Its Interaction In Human Milk Micelles, Barbara C. Dev

Loma Linda University Electronic Theses, Dissertations & Projects

Human milk K-casein was isolated from the acid-precipitated casein fraction on Sephadex G-200 and Mono Q HPLC. Samples of K-casein purified from different donors were found similar in both amino acid and carbohydrate composition. A molar extinction coefficient of 11.2 was determined on the basis of amino acid analysis with a norleucine internal standard. Tracer K-casein for human micelle studies was 3H-labeled in the sialic acid moiety of its carbohydrate. The human micelle system was investigated in its native form at 37°C. Micelle reformation by re-equilibration in skimmed milk at 4°C (overnight) followed by 3 h at 37°C was …


Trace Element Studies On Karachi Populations Part V: Blood Lead Levels In Normal Healthy Adults And Grammar School Children, W W. Manser, R Lalani, S Haider, M A. Khan Jul 1990

Trace Element Studies On Karachi Populations Part V: Blood Lead Levels In Normal Healthy Adults And Grammar School Children, W W. Manser, R Lalani, S Haider, M A. Khan

Department of Biological & Biomedical Sciences

Blood lead levels of healthy Karachi population were estimated. Mean levels for males, females, soldiers and school children were 34.4, 31.8, 29.9 and 38.2 micrograms/dl respectively. About 93% cases of either sex had elevated lead levels, of whom 30% males and 10% females had levels above the safety limits (40 micrograms/dl). Soldiers living in relatively pollution free area though had levels lower than the rest of the population but 91% had levels over 25 micrograms/dl and only two had acceptable levels. Ninety-two percent children showed levels above 25 micrograms/dl with a large number having levels over 40 micrograms/dl. A very …


The Determination Of Clomiphene Citrate And Tamoxifen In Human Blood Plasma And Semen, Janice Irene Kiss Jul 1990

The Determination Of Clomiphene Citrate And Tamoxifen In Human Blood Plasma And Semen, Janice Irene Kiss

Chemistry & Biochemistry Theses & Dissertations

Triphenylethylene antiestrogen compounds are used to stimulate ovulation in anovulary women and spermatogenesis in oligozoospermatic males. Clomiphene Citrate (CC) is given therapeuticaly as a mixture of the trans (E) and cis (Z) isomers. Each of these isomers has its own characteristic agonist-antagonist profiles. Only the trans form of Tamoxifen (T) is administered therapeutically.

HPLC methodologies were developed for the determination of CC and Tin human blood and seminal plasma. The methodologies involved extraction of the triphenylethylene compounds using hexane, followed by evaporation of the hexane under N2. The residue was then taken up in a volume of HPLC …


Microwell Based Solid Phase Competitive Enzyme Immunoassay For Estradiol And Estriol, Jeng-Ting Yang Jul 1990

Microwell Based Solid Phase Competitive Enzyme Immunoassay For Estradiol And Estriol, Jeng-Ting Yang

Chemistry & Biochemistry Theses & Dissertations

A sensitive and simple microwell based competition enzyme immunoassay for the quantitative determination of estradiol (E2) and estriol (E3) was developed. Nicrowells coated with antibody were incubated with antigen followed by adding horseradish peroxidase (HRPO) conjugate. The assay, which can be performed within two hours at room temperature, involved simultaneous incubation of E2 - or E3-HRPO conjugate and serum sample in polystyrene microwells coated with anti- E2 or anti-E3 gamma globulin fraction.

Gamma globulin was isolated from whole anti-serum by DEAE-cellulose chromatography. A carbodiimide coupling method was utilized to prepare the …


Separation Of Transfer Rna Isoacceptors By Reversed Phase W-Porex C-4 High Pressure Liquid Chromatography, Christine D. Witte Jul 1990

Separation Of Transfer Rna Isoacceptors By Reversed Phase W-Porex C-4 High Pressure Liquid Chromatography, Christine D. Witte

Chemistry & Biochemistry Theses & Dissertations

Transfer RNA (tRNA), is a complex class of small molecules which have been proven to play a major role in protein synthesis. Transfer RNA is composed of 20 families of isoacceptors which may recognize only one particular amino acid. This family of isoacceptors may differ from each other by primary sequence or modified nucleosides. Queuine is a modified nucleoside which is found in the anticodon regions of tRNA isoacceptors for asparagine, aspartic acid, tyrosine and histidine. Queuine has gained the interest of many researchers since queuine deficient tRNA was found in many neoplastic and undifferentiated cell-lines. It is often difficult …


Development Of A Solid Phase Enzyme Immunoassay For Total Serum Testosterone, Li Li Jul 1990

Development Of A Solid Phase Enzyme Immunoassay For Total Serum Testosterone, Li Li

Chemistry & Biochemistry Theses & Dissertations

An enzyme-labeled immunoassay of sufficient range and sensitivity was developed for serum testosterone determination. In this method, the testosterone in the serum sample and testosterone-HRPO conjugate compete with each other for the limited antibody binding sites on the anti-testosterone gamma globulin coated microwell. The assay can be performed in only 2.5 hours.

The gamma globulin fraction was isolated from the anti-testosterone whole serum by DEAE-cellulose column chromatography. Testosterone-peroxidase conjugate was prepared by a carbodiimide coupling method. The interference which arises from the binding of testosterone to steroid hormone binding protein was eliminated by the addition of 17 beta-estradiol. All assay …


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 …


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 …


Maternal Immunomodulation Of Neonatal Alloantigen Response, Leh Chang Jun 1990

Maternal Immunomodulation Of Neonatal Alloantigen Response, Leh Chang

Loma Linda University Electronic Theses, Dissertations & Projects

Remarkable success has been achieved in the transplantation of allogeneic cardiac grafts into newborn infants at Loma Linda University Medical Center. The superior graft survival rate documented in these patients has not correlated with the degree of immunosuppression rendered, or the selection of genetically matched donors. However, the clinical success has correlated with the age of the recipient at the time of receiving a transplant. Patients receiving an allograft within the first few weeks of life are unique in that they seem to accept the alloantigens of their cardiac graft while responding aggressively to antigens in their environment. These observations …


Purification And Characterization Of Enoyl-Acp Reductase From Euglena Gracilis, Margie M. Tucker May 1990

Purification And Characterization Of Enoyl-Acp Reductase From Euglena Gracilis, Margie M. Tucker

Electronic Theses and Dissertations

Enoyl-(acyl-carrier-protein) reductase was purified from the phytoflagellate Euglena gracilis. Its purification employed DEAE-Sephacel chromatography, Matrex Orange chromatography, and affinity chromatography using acyl carrier protein (ACP) covalently bound to Sepharose as the affinity ligand. Matrex Orange chromatography resolved two different enoyl-ACP reductases having different characteristics. Euglena gracilis appears to resemble higher plants in the possession of two isoforms of this enzyme. Antibodies specific for the cofactor binding site of NADP (H)-requiring dehydrogenases were obtained. They were isolated from a polyclonal population of antibodies directed against yeast glucose-6-phosphate dehydrogenase by affinity chromatography using chicken liver malic enzyme as the affinity ligand. The …


Energetic Requirements For Bacterial Protein Export, John Andrew Corbett May 1990

Energetic Requirements For Bacterial Protein Export, John Andrew Corbett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bacterial protein export involves the translocation of precursor proteins across the inner cytoplasmic membrane. Over 100 proteins are exported from Escherichia coli. This study showed that energy in the form of ATP and membrane gradient energy is essential for the export of leucine specific binding protein and β-lactamase precursors. Ionophores or combinations of ionophores (SF6847, valinomycin/nigericin and valinomycin/monensin) which dissipate protonmotive force inhibit protein export. Valinomycin alone also inhibits export, but not as well as reagents which dissipate protonmotive force. Nigericin or monensin alone slightly stimulate protein export. These results suggest that the transmembrane electrical potential (∆Ψ) is the …


The Role Of The Voltage Gradient In The Agarose Gel Electrophoresis Of Dna, David Wheeler Apr 1990

The Role Of The Voltage Gradient In The Agarose Gel Electrophoresis Of Dna, David Wheeler

Theses and Dissertations in Biomedical Sciences

In Part I of this dissertation, empirical equations for predicting DNA mobility during agarose gel electrophoresis (AGE) from voltage gradient are developed from the data of McDonnel (36) for electrophoresis in a 1.6% agarose gel. These equations represented the data well for DNA between 2 and 10 kilobase pairs (KBp) in length. A computer program, called GELSIM, which incorporates these equations is described in Part II. GELSIM was designed to allow researchers to analyze electrophoresis data by predicting the effect on DNA migration of altering the voltage of electrophoresis. In this way, electrophoretic banding patterns produced using different voltages could …


Some Diazinon Analogues Containing The 4-Trifluoromethyl Group / Herman Gershon, Donald D. Clarke, Anthony T. Grefig, And Thomas E. Anderson Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, Ny 14853, U.S.A. Department Of Chemistry, Fordham University, Bronx, Ny 10458, U.S.A., Herman Gershon, Donald Dudley Clarke Phd, Anthony T. Grefig, Thomas E. Anderson Jan 1990

Some Diazinon Analogues Containing The 4-Trifluoromethyl Group / Herman Gershon, Donald D. Clarke, Anthony T. Grefig, And Thomas E. Anderson Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, Ny 14853, U.S.A. Department Of Chemistry, Fordham University, Bronx, Ny 10458, U.S.A., Herman Gershon, Donald Dudley Clarke Phd, Anthony T. Grefig, Thomas E. Anderson

Chemistry Faculty Publications

Diazinon analogues were prepared containing trifluoromethyl in place of the 4-methyl group and methylthio (2a), amino (2b), dimethylamino (2c), methylphenylamino (2d), or isopropyl (2e) in position 2 of the pyrimidine ring. The most active analogue (2 b) was less than half as insecticidal as Diazinon


Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick Jan 1990

Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick

Faculty Publications, Biological Sciences

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic for mevalonate. …


Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad Jan 1990

Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad

Journal of the Arkansas Academy of Science

The compact ordered conformations of the molecule N-Acteyl-L-Prolyl-D-Alanyl-Methylamide have been studied by semiempirical energy calculations in vacuum and circular dichroism (CD) in solution. The presence of ordered structure has been observed in hydrogen bond promoting solvents like trifluoroethanol by CD studies. In hydrogen bond breaking solvents, like trifluoroacetic acid (TFA), significant fraction of the ordered conformers probably assume extended conformation without intramolecular hydrogen bonds and perhaps are in equilibrium with the fraction of compact ordered structures. The trend observed in going from nonpolar to polar solvent is also compatible with the previous NMR studies in solution. The semiempirical energy calculations …


Estuarine Studies : An Activities Text For Maine Schools, Education Division - Department Of Marine Resources Jan 1990

Estuarine Studies : An Activities Text For Maine Schools, Education Division - Department Of Marine Resources

Maine Collection

Estuarine Studies : An Activities Text for Maine Schools

Fisheries Education Unit #16 - Produced by The Education Division, Department of Marine Resources, State House Station 21, Augusta, Maine 04333-0021.

Revised 1990. Printed Under Appropriation No. 3140.3260.



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.


Rotational Symmetries Of Nuclear States: Spin Determinations In Advanced Laboratory, Wilfred J. Braithwaite Jan 1990

Rotational Symmetries Of Nuclear States: Spin Determinations In Advanced Laboratory, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

An advanced laboratory experiment is described which shows the connection between the rotational symmetries of nuclear states and the assignments of spins to discrete nuclear states. Standard angular correlation methods were used to study the two sequential gamma ray transitions in each ⁶⁰Ni nucleus, populated by unobserved beta decays from a weak radioactive ⁶⁰Co source. The chosen electronics and detectors were inexpensive and easy to operate. This experiment was extended to introduce students to real-world data acquisition, using finite-geometry detectors, which resulted in enormously larger coincident data rates.


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 …


Primary Sequence Of The Escherichia Coli Fadba Operon, Encoding The Fatty Acid-Oxidizing Multienzyme Complex, Indicates A High Degree Of Homology To Eucaryotic Enzymes, Concetta C. Dirusso Jan 1990

Primary Sequence Of The Escherichia Coli Fadba Operon, Encoding The Fatty Acid-Oxidizing Multienzyme Complex, Indicates A High Degree Of Homology To Eucaryotic Enzymes, Concetta C. Dirusso

Department of Biochemistry: Faculty Publications

In Escherichia coli at least five enzyme activities required for the beta-oxidation of fatty acids are associated with a multienzyme complex composed of two subunits in α2β2 conformation (A. Pramanik et al., J. Bacteriol. 137:469-473, 1979). In the present work, the DNA sequence of the genes encoding these two subunits, fadB and fadA, has been determined. The direction of transcription was from fadB to fadA rather than from fadA to fadB, as suggested previously (S. K. Spratt et al., J. Bacteriol. 158:535-542, 1984). Only 10 nucleotides separated the coding sequences for the two peptides, confirming …


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 …